Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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ORGANIC AND INORGANIC LIGHT ACTIVE DEVICES
AND METHODS FOR MAKING THE SAME
BACKGROUND OF THE INVENTION:
The present invention pertains to organic and inorganic light active devices,
and
hybrids thereof, and methods of making the same. More particularly, the
present
invention pertains to devices and methods for fabricating Light active devices
that
can be used for applications such as general lighting, display backlighting,
video
displays, Internet appliances, electronic books, digital newspapers and maps,
stereoscopic vision aides, head mounted displays, advanced vehicle
windshields,
solar cells, cameras and photodetectors. A mufti-color single layer light
active
device is disclosed. Also disclosed is a sequential burst driving scheme for a
mufti-color single layer display. Further disclosed are methods for making
light
active material particulate, as well as an organic Light active fiber. Still
further
disclosed are methods for fabricating injection and other plastic molded
organic
light active devices. Further still there are disclosed compositions for light
active
material.
A polymer is made up of organic molecules bonded together. Fox a polymer to be
electrically conductive it must act like a metal with the electrons in the
bonds
mobile and not bound to the atoms making up the organic molecules. A
conductive polymer must have alternate single and double bonds, termed
conjugated double bonds. Polyacetylene is a simple conjugated polymer. It is
made by the polymerization of acetylene. In the early 1970's, a researcher
named
Shirakawa was studying the polymerization of acetylene. When too much catalyst
was added, the mixture seemed to have a metallic appearance. But unlike
metals,
the resulting polyacetylene film was not an electrical conductor. In the mid-
1970's this material was reacted with iodine vapor. The result was an extreme
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increase in the conductivity of the polymer film, and ultimately resulted in a
Nobel Prize in Chemistry for the researchers who discovered it.
Although polyacetylene can be made as conductive as some metals, its
conductivity drops rapidly in contact with air. This has led to the
development of
more stable, conjugated polymers, for example, polypyrrol, polyaniline and
polytiophene.
There is now intensive development working with conjugated polymers in their
un-doped, semiconductive state. It was found that some conjugated polymers
exhibit electroluminescence when a voltage is applied. Further, the absorption
of
light by the semiconductive polymer results in positive and negative charges
that
produce an electric current. Thus, conjugated polymers can be used to make
solar
cells and light detectors.
Organic light active material ("OLAMTM") makes use of the relatively recent
discovery that polymers can be made to be conductors. Organic light emitting
diodes ("OLED") convert electrical energy into light, behaving as a forward
biased pn junction. OLAMs can be light emitters or light detectors, depending
on
the material composition and the device structure. For the purpose of this
disclosure, the term OLAM and OLED can be interchanged. In its basic form, an
OLED is comprised of a layer of hole transport material upon which is formed a
layer of electron transport material. The interface between these layers forms
a
heterojunction. These layers are disposed between two electrodes, with the
hole
transport layer being adjacent to an anode electrode and the electron
transport
layer being adjacent to a cathode electrode. Upon application of a voltage to
the
electrodes, electrons and holes are injected from the cathode electrode and
the
anode electrode. The electron and hole carriers recombine at the
heterojunction
forming excitons and emitting light.
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The basic structure of an OLED display is similar to a conventional LCD, where
the reactive material (in the LCD case, a liquid crystal, in the OLED case, a
conjugated polymer) is sandwiched between electrodes. When an electric field
is
applied by the electrodes, the OLED material is brought into an excited energy
state, this energy state drops down by the emission of photons, packets of
light.
Thus, .each pixel of the OLED display can be controlled to emit light as
needed to
create a displayed image.
OLEDs used as pixels in flat panel displays have significant advantages over
backlit active-matrix LCD displays. OLED displays have a greater viewing
angle,
lighter weight, and quicker response. Since only the part of the display that
is
actually lit up consumes power, OEDs use less power. Based on these
advantages, OLEDs have been proposed for a wide range of display applications
including computer monitors, televisions, magnified microdisplays, wearable,
head-mounted computers, digital cameras, personal digital assistants, smart
pagers, virtual reality games, and mobile phones as well as medical,
automotive,
and other industrial applications. The unstoppable march of technology often
changes the way we see the world. Now, the way we see the world is about to be
transformed by a new kind of display technology. The discovery of organic
light
emitting polymer technology (OLED) is creating a new class of flat panel
displays
that are set to change not only the nature of the display products that are
all
around us, but how they are manufactured as well. Articulated Technologies,
has
developed an advanced full color OLED display fabrication method. One of the
biggest challenges to the OLED display industry is from contamination by water
and oxygen. The materials involved in small molecule and polymer OLEDs are
vulnerable to contamination by oxygen and water vapor, which can trigger early
failure. This issue is exacerbated when non-glass substrates are used. Since
OLEDs offer the promise of a bendable display, attempts have been made to use
plastic substrates in place of glass. Elaborate barrier mechanisms have been
proposed to encapsulate the OLED device and protect the organic stack from the
ingress of water and oxygen. Also, desiccants have been used to reduce the
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contamination. Neither of these solutions is adequate, adding to the cost and
complexity of forming an OLED device. In the end, the problems caused by the
ingress of water and oxygen to the organic stack continue to pose serious
technical issues. Figure 111 illustrates a prior art OLED device. Very
basically,-
an OLED is comprised of extremely thin layers of organic material forming an
organic stack. These layers are sandwiched between an anode electrode and a
cathode electrode. When voltage is applied to the electrodes, holes and
electrons
are injected into the organic stack. The holes and electrons combine to from
unstable excitons. When the excitons decay, light is emitted.
The current state of every available OLED fabrication technology requires the
formation of very thin films of organic light emitting material. These thin
films
are formed by a variety of known techniques such as vacuum deposition, screen
printing, transfer printing and spin coating, or by the re-purposing of
existing
technology such as ink jet printing. In any case, the current state of the art
has at
its core the formation of very thin film layers of organic material. These
thin films
must be deposited uniformly and precisely. Such thin layers of organic
material
are susceptible to major problems, such as loss of film integrity,
particularly when
applied to a flexible substrate. Figure 112 illustrates a prior art OLED
device
wherein a dust spec creates an electrical short between the electrodes. The
extreme thinness of the layers of organic material between conductors also
results
in electrical shorts easily forming due to even very small specks of dust or
other
contaminants. Because of this limitation, costly cleanroom facilities must be
built
and maintained using the conventional OLED thin film fabrication techniques.
Currently, inkjet printing has gained ground as a promising fabrication method
for
making OLED displays. However, there are some serious disadvantages to the
adapting of inkjet printing to OLED display fabrication. Inkjet printing does
not
adequately overcome the problem of material degradation by oxygen and water
vapor. Figure 113 illustrates a prior art OLED device wherein the thin organic
film stack is degraded by the ingress of oxygen and/or water. Elaborate and
expensive materials and fabrication processes are still required to provide
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adequate encapsulation to protect and preserve the thin organic films. It is
difficult
to align display pixel-sized electrodes and inkjet printed OLED material with
the
accuracy needed to effect a high resolution display.
Besides attractive picture quality, an OLED display device consumes less power
than liquid crystal display technologies because it emits its own light and
does nat
need backlighting. OLED displays are thin, lightweight, and may be able to be
manufactured on flexible materials such as plastic.
Unlike liquid-crystal displays, OLEDs emit light that can be viewed from any
angle, similar to a television screen. As compared to LCDs, OLEDs are expected
to be much less expensive to manufacture, use less power to operate, emit
brighter
and sharper images, and "switch" images faster, meaning that videos or
animation
run more smoothly.
Recently, an effort has been made to create equipment and provide services for
manufacturing OLED screens. The potential OLED display market includes a
wide range of electronic products such as mobile phones, personal digital
assistants, digital cameras, camcorders, micro-displays, personal computers,
Internet appliances and other consumer and military products.
There is still a need, for example, for a thin, lightweight, flexible, bright,
wireless
display. Such a device would be self-powered, robust, include a built-in user-
input mechanism, and ideally functional as a multipurpose display device for
Internet, entertainment, computer, and communication use. The discovery of the
OLED phenomenon puts this goal within sight.
However, there are still some technical hurdles that remain to be solved
before
OLED displays will realize their commercial potential. OLED's light emitting
materials do not have a long service life. Presently, optimum performance in
commercially viable volume production is achievable only for small screens,
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around 3.5 inches square or less. Storage lifetimes of at least 5 years are
typically
required by most consumer and business products, and operating lifetimes of
>20,000 hours are relevant for most applications.
Organic light emitting diode technology offers the prospect of flexible
displays on
plastic substrates and roll-to-roll manufacturing processes. One of the
biggest
challenges to the OLED display industry is from contamination by water and
oxygen. The materials involved in small molecule and polymer OLEDs are
vulnerable to contamination by oxygen and water vapor, which can trigger early
failure. As an example of an~OLED device, US Patent No. 5,247,190 issued to
Friend et al., teaches an electroluminescent device comprising a semiconductor
layer in the form of a thin dense polymer film comprising at least one
conjugated
polymer sandwiched between two contact layers that inject holes and electrons
into the thin polymer film. The injected holes and electrons result in the
emission
of light from the thin polymer film.
There has been recent activity in developing thin, flexible displays that
utilize
pixels of electro-luminescent materials, such as OLEDs. Such displays do not
require any back lighting since each pixel element generates its own light.
Typically, the organic materials are deposited by solution processing such as
spin-
coating, by vacuum deposition or evaporation. As examples, US Patent No.
6,395,328, issued to May, teaches an organic light emitting color display
wherein
a mufti-color device is formed by depositing and patterning thin layers of
light
emissive material. US Patent No. 5,965,979, issued to Friend, et al., teaches
a
method of making a light emitting device by laminating two self-supporting
components, at least one of which has a thin layer of light emitting layer. US
Patent No. 6,087,196, issued to Strum, et al., teaches a fabrication method
for
forming organic semiconductor devices using ink jet printing for forming thin
layers of organic light emitting material. US Patent 6,416,885 B 1, issued to
Towns et al., teaches an electro-luminescent device wherein a conductive
polymer
thin layer is disposed between an organic light emitting thin layer and a
charge-
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injecting thin layer that resists lateral spreading of charge carriers to
improve the
display characteristics. US Patent 6,48,200 B1, issued to Yamazaki et al.,
teaches
a method of manufacturing an electro-optical device using a relief printing or
screen printing method for printing thin layers of electro-optical material.
US
Patent No. 6,402,579 B 1, issued to Pichler et al., teaches an organic light-
emitting device in which a multi-layer structure is formed by DC magnetron
sputtering to form multiple thin layers of organic light emitting material.
Electrophoretic displays are another type of display that has recently been
the
subject of research. US Patent No. 6,50,687 B 1, issued to Jacobson, teaches
an
electronically addressable microencapsulated ink and display. In accordance
with
the teachings of this reference, microcapsules are formed with a reflective
side
and a light absorbing side. The microcapsules act as pixels that can be
flipped
between the two states, and then keep that state without any additional power.
In
accordance with the teaching of this reference, a reflective display is
produced
where the pixels reflect or absorb ambient light depending on the orientation
of
the microcapsules.
Other examples of OLED-type displays include US Patent No. 5,858,561, issued
to Epstein et al. This reference teaches a light emitting bipolar device
consisting
of a thin layer of organic light emitting material sandwiched between two
layers
of insulating material. The device can be operated with AC voltage or DC
voltage. US Patent No. 6,433,355 Bl, issued to Riess et al., teaches an
organic
light emitting device wherein a thin organic film region is disposed between
an
anode electrode and a cathode electrode, at least one of the electrodes
comprises a
non-degenerate wide band-gap semiconductor to improve the operating
characteristic of the light emitting device. US Patent No. 6,445,126 B 1,
issued to
Arai et al., teaches an organic light emitting device wherein an organic thin
layer
is disposed between electrodes. An inorganic electrode or hole injecting thin
film
is provided to improve efficiency, extend effective life and lower the cost of
the
light emitting device.
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It is known to form a thin OLED layer by various methods including vacuum
deposition, evaporation or spin coating. Thin layers of hole transport
material and
then electron transport material are formed by these known methods over a grid
of
anode electrodes. The anode electrodes are formed on a glass plate. A grid of
cathode electrodes is then placed adjacent to the electron transport material
supported by a second glass plate. Thus, the basic OLED organic stack is
sandwiched between electrodes and glass plate substrates. It is generally very
difficult to form the electrodes with the precise alignment needed for forming
a
pixilated display. This task is made even more difficult in a multicolor
display,
where the OLED pixels emitting, for example, red, green and blue, are formed
side-by-side to fabricate a full color display. Because the OLED material and
electrodes can be made transparent, it is possible to stack the color OLED
pixels
on top of each other, allowing for a higher pixel packing density and thus the
potential for a higher resolution display. However, the electrode alignment
issue
still poses a problem. Typically, the well-known use of shadow masks are
employed to fabricate the pixel components. Aligning the shadow masks is
difficult, and requires extreme precision.
Currently, inkjet printing has gained ground as a promising fabrication method
for
making OLED displays. The core of this technology is very mature, and can be
found in millions of computer printers around the world. However, there are
some serious disadvantages to the adapting of inkjet printing to OLED display
fabrication. It is still difficult to lay down precise layers of material
using the
spray heads of inkjet printers. Inkjet printing does not adequately overcame
the
problem of material degradation by oxygen and water vapor. Elaborate and
expensive materials and fabrication processes are needed to provide adequate
encapsulation of the display elements to prevent early degradation of the OLED
material due to water and oxygen ingress. As an attempt to solve this
contamination problem, Vitex Systems, Sunnyvale, CA, has developed a barrier
material in which a monomer vapor is deposited on a polymer substrate, and
then
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the monomer is polymerized. A thin layer of aluminum oxide a few hundred
angstroms thick is deposited on the polymerized surface. This process is
repeated
a number of times to form an encapsulation barrier over an OLED display. This
elaborate encapsulation barrier is an example of the effort taken to prevent
water
and oxygen from contaminating the easily degraded OLED films that form a
conventional OLED display device. Even with this elaborate encapsulation
process, the edges of the OLED display still need to be sealed.
It is difficult to align display pixel-sized electrodes and inkjet printed
OLED
material with the accuracy needed to effect a high resolution display. All of
the
known fabrication methods for manufacturing an OLED device require the
formation and preservation of very thin layers of reactive organic material.
These
ultra thin layers are disposed between oppositely charged electrodes.
Electrical
shorts and the destruction of pixels result from the inclusion of even
miniscule
foreign particles when forming the organic thin film layers. To limit this
serious
drawback, the conventional fabrication processes requires the use of expensive
clean room or vacuum manufacturing facilities. Even with a gh clean room or
vacuum chamber, the typical OLED display device either has to use glass
substrates or an elaborate encapsulation system to overcome the problems of
water and oxygen ingress. Accordingly there is an urgent need for an improved
fabrication method for forming OLED devices.
There is also a need for a multi-color OLED structure whereby two or more
colors
of light can be produced from a single pixel or OLED device. US Patent No.
6,117,567, issued to Andersson et al, teaches a light emitting polymer device
for
obtaining voltage controlled colors based on a thin polymer film incorporating
more than one electroluminescent conjugated polymer. The polymer thin film is
sandwiched between two electrodes. Upon application of different voltages to
the
electrodes, different colors of light are emitted from the conjugated polymers
contained in the thin film. It is hoped that multiple color OLED films will
somehow facilitate the formation of a full color emissive display screen.
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Typically, a full color display is obtained by forming pixels comprised of
three
separately controllable subpixels. Each subpixel is capable of controlling the
emission of a wavelength of one of the three primary colors light, red, green
and
blue.
Edwin Land introduced a theory of color vision based on centerlsurround
retinex
(see, An Alternative Technique for the Computation of the Designator in the
Retinex Theory of Color Vision," Proceedings of the National Academy of
Science, Volume 83, pp. 3078-3080, 1986). Land disclosed his retinex theory in
"Color Vision and The Natural Image," Proceedings of the National Academy of
Science, Volume 45, pp. 115-129, 1959. These retinex concepts are models for
human color perception. Others have shown that a digital image can be improved
utilizing the phenomenon of retinex (see, U.S. Patent No. 5,991,456 issued to
Rahman et al, the disclosure of which is incorporated by reference herein).
The
inventors of the 5,991,456 patent used Land's retinex theory and devised a
method of improving a digital image where the image is initially represented
by
digital data indexed to represent positions on a display. According to the
inventors
of the 5,991,456 patent, an improved digital image can then be displayed based
on
the adjusted intensity value for each i-th spectral band so-filtered for each
position. For color images, a novel color restoration step is added to give
the
image true-to-life color that closely matches human observation.
Nanoparticles are used in unrelated applications, such as drug deliver
devices.
Others have shown that very small polymer-based particles can be made by a
variety of methods. These drug delivery nanoparticles vary in size from 10 to
1000 nm. A drug can be dissolved, entrapped, encapsulated or attached to a
nanoparticle matrix. Depending on the method of preparation, nanparticles,
nanospheres or nanocapsules can be obtained. (see, Biodegradable Polymeric
Na~ZOparticles as Drug Delivery Devices, K.S., Soppimath et al., Journal of
Controlled Release, 70(2001) 1-20).
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Recently, researchers have demonstrated a process for making a composite
material comprised of polymer interspersed with liquid-crystal droplets. The
optical response of this material can be controlled by applying a voltage, and
has
been used to create photonic crystals that modulate the transmission of light.
(see,
Liquid-Crystal Holograms Forfn Photoyzic Crystals, by Graham P. Collins,
Scientific American, July, 2003). A mixture of monomer molecules and liquid-
crystal molecules are disposed between two sheets of a substrate. The
substrate
can be, for example, glass plated with a thin layer of conducting material.
The
mixture is irradiated with two or more laser beams. The laser beams are
aligned
and polarized to generate a specific holographic interference pattern having
alternating dark and light areas. At the bright regions in the pattern, the
monomers undergo polymerization. As the polymerization reaction progresses,
the monomer migrates from the dark regions to the bright regions, causing the
liquid crystal to become concentrated in the dark regions. The end result is a
solid
polymer with droplets of liquid crystal embedded in a pattern corresponding to
the
dark regions of the holographic interference pattern.
The current state of the OLED fabrication technology requires the formation of
very thin films of organic light emitting material. These thin films are
formed by
known techniques such as vacuum deposition, screen printing, transfer printing
and spin coating, or by the re-purposing of existing technology such as ink
jet
printing. In any case, the current state of the art has at its core the
formation of
very thin film layers of organic material. These thin films must also be
deposited
very uniformly and precisely, which has proven extremely difficult to do.
These
thin layers of organic material are susceptible to major problems, such as
shortened device lifetime due to ingress of water and oxygen, and
delamination,
particularly when applied to a flexible substrate. The extreme thinness of the
layers of organic material between conductors also results in electrical
shorts
easily forming due to even very small specks of dust or other contaminants.
Because of this limitation, costly cleanroom facilities must be built and
maintained using the conventional OLED thin film fabrication techniques.
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Organic light emitting devices offer tremendous potential due to the inherent
qualities of the organic materials, however, the current state of the art
fabrication
methods are limiting the delivery of this potential to the consumer.
SUMMARY OF THE INVENTION:
It is an object of the present invention to overcome the drawbacks of the
prior art.
It is an object of the present invention to provide a method of fabricating a
light
active device by dispersing three dimensionally a semiconductor particulate
within a carrier material. The resulting structure has individual point
sources of
light emission dispersed within a protective barrier material. The barrier
material
provides strength to the device and adhesion to the electrodes and/or other
films
and prevents contamination of the semiconductor particulate. The inventive
fabrication method also allows multiple colors to be emitted from the
inventive
mixture between a single pair of electrodes forming a pixel or device. In an
inventive display driving scheme, an array of such pixels is driven so that
bursts
of color emissions occur in rapid succession resulting in the perception by
the
human eye of a range of colors in the visible spectrum. Thus, in accordance
with
this aspect of the invention, a single emissive layer and pair of electrodes
can be
used to create a full color video display. The inventive Organic Light Active
Material (OLAMTM) structure can also be used to detect a spectrum of colors
when the device is constructed as a photodetector.
It is another object of the present invention to provide a light active fiber
that has
the advantages of the OLED phenomenon. The inventive light active fiber
includes an elongated hardened conductive carrier material. A semiconductor
particulate is dispersed within the conductive carrier material. A first
contact area
is provided so that on application of an electric field charge carriers of a
first type
are injected into the semiconductor particulate through the conductive carrier
material. A second contact layer is provided so that on application of an
electric
field to the second contact layer charge carriers of a second type are
injected into
the semiconductor particulate through the conductive carrier material. The
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semiconductor particulate may comprise at least one of an organic and an
inorganic semiconductor.
The conductive carrier material may comprise a binder material with one or
more
characteristic controlling additives. The characteristic controlling additives
are a
particulate and/or a fluid and may include a dessicant; a conductive phase, a
semiconductive phase, an insulative phase, a mechanical strength enhancing
phase, an adhesive enhancing phase, a hole injecting material, an electron
injecting material, a low work metal, a blocking material, and an emission
enhancing material
The first and the second contact may comprise a first conductive member
disposed longitudinally within the elongated hardened conductive carrier
material.
The other of the first and the second contact may comprises a second
conductive
member disposed adjacent to the first conductive member so that at least a
portion
of the semiconductor particulate is disposed between the first conductive and
the
second conductive member.
The first conductive member comprises a conductive material comprised of at
least one of a metal and a conductive polymer disposed in the interior of the
elongated hardened conductive carrier material; and the second conductive
member comprises a conductive material comprised of at least one of a metal
and
a conductive polymer disposed as a coating on the exterior of the elongated
hardened conductive carrier material.
In accordance with another aspect of the present invention, an injection
moldable
light active material is provided comprising: a semiconductor light active
particulate dispersed within a hardenable carrier material. The semiconductor
light active particulate may include at least one of an organic and an
inorganic
semiconductor. The organic light active particulate can include particles
including at least one of hole transport material, organic emitter, and
electron
transport material. The organic light active particulate can include particles
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including a polymer blend. The polymer blend may include an organic emitter
blended with at least one of a hole transport material, an electron transport
material and a blocking material. Additional organic emitters can be included
within the polymer blend. The organic light active particulate can comprise
microcapsules including a polymer shell encapsulating an internal phase
comprised of a polymer blend.
The carrier material can be a hardenable binder material with one or more
characteristic controlling additives. The characteristic controlling additives
may
include at least one of a particulate and a fluid. The characteristic
controlling
additives may include a dessicant, a scavenger, a conductive phase, a
semiconductive phase, an insulative phase, a mechanical strength enhancing
phase, an adhesive enhancing phase, a hole injecting material, an electron
injecting material, a low work metal, a blocking material, and an emission
enhancing material. The particulate may include at least one of an organic
emitter, an inorganic emitter, hole transport material, blacker material,
electron
transport material, and performance enhancing materials. The carrier may
include
at least one of an organic emitter; an inorganic emitter, hole transport
material,
blacker material, electron transport material, and performance enhancing
materials (e.g., the characteristic controlling additives).
In accordance with the present invention, the injection moldable light active
material can be provided wherein the semiconductive light active particulate
is
comprised of first emitting particles for emitting a number of photons of a
first
color in response to a first turn-on voltage applied to the electrodes and
emitting a
different number of photons of the first color in response to other turn-on
voltages. The semiconductive light active particulate may further include
second
emitting particles. The second emitting particles emit a number of photons of
a
second color in response to a second turn-on voltage and a different number of
photons of the second color in response to other turn-on voltages. By this
composition and construction, a mufti-colored light active material is
obtained.
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The particulate can be composed so as to have a first end having an electrical
polarity and a second end having an opposite electrical polarity. The
particulate is
alignable within the conductive carrier so that charge carriers of a first
type are
more easily injected into the first end and charge carriers of a second type
are
more easily injected into the second end.
In accordance with another aspect of the present invention, a photon receptive
light active device is provided.. A first electrode and a second electrode are
provided disposed adjacent defining a gap there between. A light active
mixture
is provided comprised of a carrier material and a photon receptive particulate
for
receiving a photon of light and converting the photon of light into electrical
energy. The light active mixture being disposed within the gap between the
first
electrode and the second electrode so that when light energy is received by
the
photon receptive particulate, electrical energy is produced that can be
derived
from an electrical connection with the first electrode and the second
electrode.
With this composition and construction, a light-to-energy device is obtained
from
which a solar cell, photodetector or camera element can be made.
The photon receptive particulate may include at least one of an organic photon
receiver; an inorganic photon receiver, hole transport material, blocker
material,
electron transport material, and performance enhancing materials. The carrier
can
include at least one of an organic photon receiver; an inorganic photon
receiver,
hole transport material, blocker material, electron transport material, and
performance enhancing materials. Further, additional layers may be formed
within the gap between the first electrode and the second electrode. These
additional layers help to define the mechanical, electrical and optical
characteristics of the inventive device. The additional layers may include at
least
one of an organic photon receiver; an inorganic photon receiver, hole
transport
material, blocker material, electron transport material, and performance
enhancing
materials (e.g., the characteristic controlling additives).
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Applicants have discovered that the ultra thin film nature of a conventional
organic light active device results in many disadvantages. These disadvantages
include, but are not limited to, electrical shorts caused by the inclusion of
small
foreign particles, cross talk among pixels in a display array, delamination of
the
thin film, deterioration of the thin film by the ingress of oxygen and water,
and
other serious failings. In accordance with the present invention, the
disadvantages
caused by having an extremely small gap distance between electrodes is
overcome
by expanding this gap distance. Thus, in accordance with the present
invention,
an organic light active device includes a first electrode and a second
electrode
disposed adjacent to the first electrode. The first and second electrode
define a
gap there between. An organic emissive layer is' disposed within said gap. To
overcome the thin.film issues, and to enhance the performance of the inventive
device, a gap expanding composition is also disposed within said gap. This gap
expanding composition is effective to increase the gap distance between the
top
and bottom electrode.
The gap expanding composition may include at least one of an insulator, a
conductor and a semiconductor. The gap expanding composition can include at
least one additional layer formed between the first electrode and the second
electrode. The additional layers may include at least one of an organic photon
receiver; an inorganic photon receiver, hole transport material, blocker
material,
electron transport material, radiation emitting material and performance
enhancing materials. The gap expanding composition can include at least one of
a
dessicant; a scavenger, a conductive material, a semiconductive material, an
insulative material, a mechanical strength enhancing material, an adhesive
enhancing material, a hole injecting material, an electron injecting material,
a low
work metal, a blocking material, and an emission enhancing material.
The emissive layer can comprise an emissive particulate dispersed within a
carrier.
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The emissive particulate has a first end having an electrical polarity and a
second
end having an opposite electrical polarity. The particulate can be alignable
within
the conductive carrier so that charge carriers of a first type are more easily
injected into the first end and charge carriers of a second type are more
easily
injected into the second end.
The emissive layer may be an organic thin film layer. The gap expanding
composition can include a conductive, insulative andlor semiconductive
material
composition that reduces the emission efficiency of the emissive layer while
increasing the light active device effectiveness by expanding the gap distance
between the electrodes. With a careful selection of constituent components,
this
reduction in efficiency can be limited so that the benefits of expanding the
gap
distance between the electrodes can be obtained without too much cost in
device
efficiency.
In accordance with another aspect of the present invention, a light active
device
includes a semiconductor particulate dispersed within a carrier material. A
first
contact layer is provided so that on application of an electric field, charge
carriers
having a polarity are injected into the semiconductor particulate through the
conductive carrier material. A second contact layer is provided so that on
application of the electric field to the second contact layer, charge carriers
having
an opposite polarity are injected into the semiconductor particulate through
the
conductive carrier material. The semiconductor particulate comprises at least
one
of an organic and an inorganic semiconductor. The semiconductor particulate
may comprise an organic light active particulate that includes at least one
conjugated polymer. When an electric field is applied between the first and
second contact layers to the semiconductor particulate through the conductive
carrier material, the second contact layer becomes positive relative to the
first
contact layer and charge carriers of opposite polarity are injected into the
semiconductor particulate. The opposite polarity charge carriers combine to
form
in the conjugated polymer charge carrier pairs which decay radiatively so that
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radiation is emitted from the conjugated polymer. In this case, the inventive
light
active device acts as a light emitting diode.
Importantly, the present invention can be used with small molecule OLED
materials as well as large molecule OLED materials. It is very difficult or
impossible to dissolve small molecule OLED materials in a liquid and so the
current state-of-the-art requires such material to be vacuum deposited as a
very
thin film to form an OLED device, using for example, a process similar to the
fabrication of a computer microprocessor chip. But because the displays are
typically much larger than chips, that fabrication process is prohibitively
expensive for forming a large display. However, in accordance with the present
invention, particulate of the small molecule OLED material can be mixed with
the
carrier material aisposed within the gap between the electrodes. The
particulate can include other materials, such as organic and inorganic
characteristic enhancing materials to control the electrical, chemical,
optical,
mechanical and magnetic properties of the light active device.
The organic light active particulate may include particles comprised from a
polymer blend. The polymer blend including at least one organic emitter
blended
with at least one of a hole transport material, a blocking material, and an
electron
transport material. The organic light active particulate may include
microcapsules
having a polymer shell encapsulating an internal phase. The internal phase
and/or
the shell can be comprised of a polymer blend including an organic emitter
blended with at least one of a hole transport material, a blocking material,
and an
electron transport material.
To form a display device, the first contact layer and the second contact layer
can
be arranged to form an array of pixel electrodes. Each pixel includes a
portion of
the semiconductor particulate dispersed within the conductive carrier
material.
Each pixel is selectively addressable by applying a driving voltage to the
appropriate first contact electrode and the second contact electrode.
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Another aspect of the present invention provides a voltage controlled light
active
device for emitting two or more colors of light. A first electrode and a
second
electrode are disposed adjacent to each other with a gap between them. A
mixture
of an organic light active particulate and a conductive carrier material is
disposed
within the gap. Because of the particulate/carrier mixture, the gap between
the
electrodes (or whatever layers are sandwiching the organic emissive layer) can
be
much wider than the thickness of°the emissive particulate. The
particulate is
dispersed three dimensionally throughout a conductive carrier. By this
construction, many of the drawbacks, such as electrical shorts, delamination,
etc.,
that plague the very thin polymer film fabrication methods are overcome.
In the voltage controlled multi-color embodiment, the organic light active
particulate is comprised of first emitting particles including a first
electroluminescent conjugated polymer. The first emitting particles emit a
number of photons of a first color in response to a first turn-on voltage
applied to
the electrodes. The first emitting particles also emit a different number of
photons, zero or more, of the first color in response to other turn-on
voltages. The
organic light active particulate further comprises second emitting particles
including a second conjugated polymer. The second emitting particles emit a
number of photons of a second color in response to a second turn-on voltage
and a
different number of photons of the second color in response to other turn-on
voltages. Thus, in the case of a mufti-colored diode or display, different
colors
are perceivable by the human eye depending on the applied turn-on voltage.
The organic light active layer may also include third emitting particles
including a
third electroluminescent conjugated polymer. The third emitting particles emit
a
number of photons of a third color and/or intensity in response to a third
turn-on
voltage applied to the electrodes and a different number of photons of the
third
color and/or intensity in response to other turn-on voltages. A full color
display
can be obtained by incorporating an array of pixels, each capable of emitting
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different colors, such as a first color red, a second color green and a third
color
blue. The color emitters can be a mix of organic and inorganic materials. For
example, an organic conjugated polymer emitter can be used as a red emitter
and
an inorganic rare earth metal or metal alloy, or doped inorganic
semiconductor,
can be used as a green emitter. This combination of organic and inorganic
emitters may expand the potential candidates for emissive materials enabling
the
inventive device to be tuned for specific applications.
The voltage controlled organic light active device can be constructed as a
display.
In this case, the first electrode is part of an x-grid of electrodes and the
second
electrode is part of a y-grid of electrodes. The mixture of the organic light
active
particulate and the conductive carrier material in the gap between the first
electrode and the second electrode make up an emissive component of a pixel of
a
display device. Depending on the device structure it can be driven as a
passive
matrix or an active matrix device.
In accordance with the present invention, an organic light active display
device
includes a substrate with a first grid of driving electrodes formed on the
substrate.
A second grid of electrodes is disposed adjacent to the first grid of
electrodes and
defines a gap there- between. A mixture of an organic light active particulate
and
a conductive carrier material is disposed within the gap. The organic light
active
particulate includes first particles. including a first electroluminescent
conjugated
polymer having a first turn-on voltage and second particles including a second
electroluminescent conjugated polymer having a second turn-on voltage
different
than the first turn-on voltage. When the first turn-on voltage is applied, a
first
color is emitted by the first electroluminescent conjugated polymer. Light
having
a second color is emitted by the second electroluminescent conjugated polymer
in
response to the second turn-on voltage applied to the first electrode and the
second electrode. Additional color emitters can be included, including
emitters
that emit photons predominately in the visible andlor non-visible range of the
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photon radiation spectrum. Also, the color emitters can be comprised of other
organic or inorganic materials.
In accordance with the present invention, a method is provided for driving a
multi-color light emitting device, the multi-color light emitting device is
capable
of emitting two or more colors in sequence. Each color is emitted in response
to a
respective different applied turn-on voltage. During an emission cycle, a
first turn-
on voltage is applied having a duration to the light emitting device so that a
first
burst of a predominant number of photons of a first color are emitted. A
second
turn-on voltage is then applied during the emission cycle having a duration
and at
least one of a magnitude and a polarity different than a magnitude and
polarity of
the first turn-on voltage. For example, a 5 volt turn-on voltage may cause a
predominate emission of red photons, and a 10 volt turn-on voltage may cause a
predominate emission of green photons. In response to the second turn-on
voltage
duration, a second burst of a predominant number of photons of a second color
are
emitted. In this way, during the emission cycle the first burst and the second
burst, (and possibly third or more burst), occur in rapid succession. A human
eye
and vision system receiving the first burst and the second burst, and so on,
is
stimulated to perceive a color that is different than the first color and the
second
color (the emitted burst colors).
In accordance with another aspect of the present invention, a method is
provided
for forming a layered organic light active material particulate. This layered
organic light active material particulate is mixed with the conductive carrier
material and disposed between the electrodes to form the inventive light
emitting
devices. To form the particulate,°a first mixture is formed of a first
organic light
active component material and a first carrier fluid. A second mixture is
formed of
a second organic light active component material and a second carrier fluid. A
first mist is generated of the first mixture in an environment so that a first
particulate of the first organic light active component material is
temporarily
suspended in the environment. A second mist of the second mixture is generated
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in the environment so that a second particulate of the second organic light
active
component material is temporarily suspended in the environment. The first
particulate and the second particulate are allowed to commingle and attract
together in the environment to form a first layered organic light active
material
particulate. A charge of opposite polarity can be applied to the constituents
in
each mist to promote electrical attraction. When the charged particles join
together an electrically neutral organic light active particulate is obtained.
The
layered organic light active particulate has a first layer made up of the
first
organic light active component material and a second layer made up of the
second
organic light active component material. Additional layers can be added to the
multilayered structure by forming another mixture of another organic light
active
component material and another carrier fluid and forming yet another mixture
of a
previously formed layered organic light active material particulate and yet
another
carrier fluid. The resulting particles are suspended in the environment as
described above and allowed to commingle and attract together to form the
multilayered particulate stmcture. This method can be repeated to build up
multilayered organic light active material particulate having a range of
selectable
electrical, optical, mechanical and chemical attributes. Further, depending on
the
desired particulate characteristics, the constituents of the multilayered
structure
may be organic and/or inorganic materials. The use of organic and inorganic
materials broadens the potential candidates of materials that can be combined
to
form the multilayered particulate. Further, the inventive method may be
applied
for making multilayered particles for other applications, such as drug
delivery
vehicles, electrical circuit components, bi-polar electrophoretic
microdevices,
nanomachines, etc.
The environment in which the particulate is formed can be an inert gas,
reactive
gas, a vacuum, a liquid or other suitable medium. For example, it may be
advantageous for the environment to include elements that perform a catalytic
function to promote a chemical reaction in or between the constituents in the
mists. A characteristic enhancing treatment may be performed on the formed
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layered organic light active material particulate. The treatment may be a
temperature treatment, a chemical treatment, a light energy treatment to
cause, for
example, light activated cross-linking, a shell forming treatment, or other
characteristic enhancing treatment to impart desired attributes to the formed
particulate. Further, it may be beneficial to form the particulate under
controlled
conditions such as weightlessness. The treatments can be performed on the
constituent materials and/or the multilayered particles to impart specific
characteristics or improved qualities. For example, a heat treatment may be
performed to drive out moisture or oxygen or other contaminants to increase
the
lifetime and emission efficacy of the particulate. A hot isostatic heat
treatment
can be performed to enhance the interface between the constituent particle
layers.
The particles can be brought up to about 80% of the melt temperature and
placed
under pressure in an inert atmosphere. The interface between the multilayers
can
then become diffused which may result in enhancements of the particulate
characteristics.
In accordance with the present invention, an OLED device includes a first
electrode and a second electrode. The second electrode is disposed adjacent to
the
first electrode so that a gap is defined between them. Unlike the prior art,
the
present invention does not require the formation and preservation of thin
films of
OLED material with extremely wide surface area (as compared to the film
thickness) and very little material between the electrodes. Instead, the
present
invention utilizes OLED particulate dispersed within a conductive carrier. The
OLED particulate is dispersed within the carrier material, which is disposed
within the gap between the electrodes. When an electric potential is applied
to the
electrodes, the electrical energy passes through the carrier material raising
the
energy state of the OLED particulate, resulting in the emission of light.
In a simple form, the OLED particulate may comprise layered organic particles,
each particle including a hole transport layer and an electron transport
layer. A
heterojunction is formed at the interface between the hole transport layer and
the
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electron transport layer. Each layered organic particle may also include a
blocking layer adjacent to the electron transport layer and an emissive layer
adjacent to the hole transport layer (or other stack order and component
layers),
thereby forming a stacked organic layered structure. The blocking layer is
provided for facilitating the injection and combining of electrons and holes,
and
the emissive layer is provided fox facilitating the emission of photons when
the
energy state of the OLED particulate is raised.
In accordance with an aspect of the present invention, the OLED particulate
comprises microcapsules. Each microcapsule includes an internal phase and a
shell. The internal phase and/or the shell include the OLED material. The
internal phase and/or the shell may also include a field reactive material.
Depending on the OLED fabrication method and the desired OLED
characteristics, the field reactive material may be an electrostatic material
and/or a
magnetically reactive material.
As described further herein, the microcapsule or particulate composition may
be
effective for enabling a "self healing" capability of the fabricated OLED
device.
In this case, the microcapsule includes a composition that causes the
microcapsule
to rupture or otherwise change shape if electrical energy above a threshold is
applied to the microcapsule. For example, a particular microcapsule may end up
positioned so that during use of the OLED device, it becomes a short between
the
electrodes. The microcapsule may end up positioned adjacent to a dust particle
or
other foreign inclusion, creating such a short. Tn this case, electrical
energy
exceeding a predetermined threshold will pass through the microcapsule causing
the capsule to become disrupted and disconnect the short. By this
construction,
the microcapsule is automatically removed from the path of conduction of
electrical energy in the event of a short. Further, a particulate mixture can
include
different species of emitters. The different species can each have a
particular
turn-on voltage. Two or more of the species can emit the same color of light,
but
have different turn-on voltages. Typically, different color emitters have
different
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service lifetimes. For example, a blue emitter may have a shorter service life
than
a red emitter, and a green emitter may have a service life between the other
two.
As the emitters of one color lose their potency, the display loses its color
vibrancy
and display effectiveness. However, in accordance with this aspect of the
invention, more than one species of a specific color OLED particulate can be
included in the particulate mixture. Each species has a different turn-on
voltage at
which it most effectively emits the colored light. The loss of intensity of,
say, the
blue emitter, can be detected and the other blue emitter species driven by
altering
the pixel driving voltage.
In accordance with another aspect of the invention, the microcapsule shell
and/or
internal phase may include a composition effective to provide a barrier
against
degradation of the OLED material. The OLED microcapsules are dispersed
within a carrier fluid. This carrier fluid also provides a barrier against the
intrusion of substances which degrade the OLED material.
The OLED microcapsules can have constituent parts including at least one of
hole
transport material, electron transport material, field reactive material,
solvent
material, color material, shell forming material, barrier material, desiccant
material, scavenger material, and heat meltable material. The constituent
parts
form at least one internal phase and at least one shell. The constituent parts
are
selected so as to have electrical characteristics that result in a preferred
path of
electrical conduction through the hole transport material and the electron
transport
material. By this construction, the microcapsule behaves, for example, as a pn
junction upon application of an electrical potential to the first electrode
and the
second electrode.
The OLED device can be constructed of suitably chosen materials so that the
carrier material is relatively less electrically conductive than the OLED
particulate, this ensures that the OLED particulate offers a path of less
electrical
resistance than the carrier material. Thus, the electric potential applied to
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electrodes will pass through the carrier material, which has some electrical
conductivity, and through the OLED particulate, which has relatively higher
electrical conductivity. In this way, the preferred path of electrical
conduction is
through the OLED particulate. Likewise, the shell of the OLED microcapsules
are relatively less electrically conductive than the OLED material itself, so
that
the OLED material offers a path of less electrical resistance than the shell.
The typical OLED includes an OLED component that is a hole transport material
and an OLED component that is an electron transport materil. In accordance
with a formulation of the inventive microcapsules, the shell comprises an OLED
component material that is either the hole transport material or the electron
transport material, and the internal phase of the microcapsule includes the
OLED
component material that is the other of the hole transport material and the
electron
transport material. Depending on the desired optical qualities of the
fabricated
OLED device, the carrier material can be selected so that it has optical
properties
during use of the OLED device that are transparent, diffusive, absorptive,
and/or
reflective to light energy. During the hardening process of the carrier, it
can be
selectively cured so that it is more light transmissive through the volume
between
the top and bottom electrodes and less light transmissive or more light
absorbing
through the volume that is not between the electrodes. With this construction,
the
contrast of the display is improved and ambient light is absorbed rather than
reflected from the display to reduce glare. Also, depending on the composition
of
the carrier material and characteristic enhancing material incorporated in it,
the
selective curing of the carrier fluid can control the conduction of electrical
energy
through it. In this way, the volume between the pixels is controlled to be
less
conductive than the volume between the top and bottom electrodes of each
pixel.
This mechanism further reduces cross talk between the pixels. Further, the
OLED
particulate may be more conductive than the carrier material. The composition
of
the OLED particulate can be selected so that the electrical characteristics of
the
OLED particulate includes an electro or magneto rheological characteristic.
This
rheological characteristic is effective for causing the OLED particulate to
move
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within the carrier and orient in response to an applied electrical or magnetic
field.
By migrating the OLED particulate to the regions of the pixels during the
particulate aligning step, the carrier material volume between the pixels will
have
a lower conductivity than the volume between the top and bottom electrodes.
This will also reduce cross talk between the pixels.
In accordance with another composition of the OLED microcapsule, the internal
phase comprises OLED material and a magnetically reactive material disposed
within a first shell. An electrolyte and a curable fluid material are disposed
surrounding the shell. A second shell encapsulates the first shell, the
electrolyte
and the curable material. In response to an applied magnetic field, the
position of
the first shell is changeable relative to the second shell. Upon curing the
curable
material, the position of the first shell relative to the second shell is
locked in
place. As is described in detail herein, this microcapsule structure can be
used to
form capacitorlOLED microcapsules which may be particularly effective for use
in passive matrix displays. This construction can be used to form other
electronically active microcapsules for forming electronic circuit components.
For example, semiconductor characteristics of the OLED-type polymers andlor
inorganic materials can enable transistor, capacitor and other electronic
circuit
elements to form, for example, memory, processing, transceivers, power
supplies
and other electronic circuit devices.
In accordance with the present invention, a method for forming an OLED device
is provided. A top electrode and a bottom electrode are provided defining a
gap
there between. Within the gap, a field reactive OLED particulate is disposed
randomly dispersed within a fluid carrier. An aligning field is applied
between
the top electrode and the bottom electrode to form a desired orientation of
the
field reactive OLED particulate within the fluid carrier. The fluid carrier
comprises a hardenable material. While the desired orientation of the field
reactive OLED particulate is maintained, the carrier is cured to form a
hardened
support structure within which is locked in position the OLED particulate. In
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some cases it may not be necessary to align the particles by migration through
the
carrier fluid. They can remain randomly dispersed, or simply rotated so that
the
bipolar particulate, for example, is properly oriented between the electrodes
to
improve the electrical to light or light to electrical energy conversion.
The OLED particulate may comprise a bipolar OLED microcapsule. The OLED
particulate is formed by the steps of first providing a first particle
comprised of a
hole transport material. The hole transport material has a net first
electrical
charge. A second particle comprised of an electron transport material is
provided
having a net second electrical charge. The first electrical charge is of
opposite
polarity from the second electrical charge. The first particle and the second
particle are brought together to form a unified OLED particulate having a hole
transport layer and an electron transport layer forming a heterojunction
between
them. The first particle may further include a photon-active layer. This
photon-
active layer may be a light emissive layer in which case the OLED forms a
light
emitting device, or a light receptive layer, in which case the OLED forms a
light
detecting device.
The OLED particulate can be formed by microencapsulating an internal phase
within a shell. The internal phase or the shell includes an OLED material and
either the internal phase or the shell includes a field reactive material. The
field
reactive material comprises either or both an electrostatic and a magnetically
reactive material. In accordance with another composition of the inventive
microcapsule, the internal phase comprises an OLED emitter material and other
materials (such as an OLED hole transport material) dispersed in solution
andlor
suspension, or a polymer blend. Color dyes may also be included within the
internal phase or shell. The fluid within the internal phase may be a carrier
fluid
or solvent. In order to provide the alignment capabilities of the
microcapsules,
either the internal phase or the shell may include a field reactive component.
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In accordance with another aspect of the present invention, a stacked OLED
device is provided. The inventive OLED device includes a first OLED pixel
layer
comprised of a first layer electrode. A second layer electrode is disposed
adjacent
to the first layer electrode. A first layer gap is defined between the
electrodes. An
OLED particulate is dispersed within a carrier and contained within the first
layer
gap. At least one subsequent OLED pixel layer is formed over the first OLED
pixel layer. Each subsequent OLED pixel layer includes a first subsequent
layer
electrode. A second subsequent layer electrode is disposed adjacent to the
first
subsequent layer electrode defining a second layer gap there between. An OLED
particulate in a carrier material is disposed between the electrodes.
To achieve a full color OLED display, the OLED particulate of the first OLED
pixel layer emits light of a first wavelength range in response to a drive
voltage
being applied to the first layer electrode and the second layer electrode.
Each
subsequent OLED pixel layer emits light of a different wavelength range in
response to the driving voltage applied to the respective electrode pairs so
that an
RGB color display can be formed.
Further, a dichromatic pixel layer can be formed adjacent to the last
subsequent
OLED pixel layer. The dichromatic pixel layer can be formed from an LCD
display-type layer or from a electrophoretic microcapsule display layer along
the
lines described in the 6,50,687 B 1 patent issued to Jacobson. This
dichromatic
pixel layer, as described more fully herein, results in a display that can
viewed in
direct bright sunlight as well as with improved contrast in indoor ambient
lighting
conditions. Further, additional subsequent OLED pixel layers can be provided
which emit light in additional color range having a color andlor light
intensity
different from the color andlor light intensity of the other OLED pixel
layers. In
this construction, the display can be driven, for example, as an infrared
display for
stealth night-vision applications.
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Further, the inventive OLED device can be configured so as to detect light
impinging on a pixel grid formed in accordance with the present invention. In
this
case, the OLED particulate of a first OLED pixel layer emits an electrical
energy
in response to the reception of photons and applies the electrical energy as a
detectable signal to the first and second layer electrodes. Further, a full
color
CCD-type camera can be formed by tuning the wavelength range at which
subsequent layers of OLED pixels are photo reactive.
In accordance with another aspect of the present invention, a method is
provided
for making a light active device. A mixture is provided containing a monomer
and light active material. The light active material contains at least one of
a
energy-to-light material for emitting light in response to an applied
electrical
energy and a radiation-to-energy material and generating electrical energy in
response to irradiation. The monomer is selectively cross-linked in a pattern
to
form a polymer. As the cross-linking reaction progresses, the monomer migrates
in response to the selective cross-linking pattern, causing the cross-linked
monomer (a polymer) and the light active material to become concentrated in
separate regions. The end result is a solid polymer with light active regions
embedded in a pattern corresponding to the selective cross-linking pattern.
In accordance with another aspect of the present invention, a light active
device is
provided. Light active material is provided in a first region. A polymer is
provided in a second region. The polymer is formed by selectively cross-
linking a
monomer from a mixture containing the monomer and the light active material.
The selective cross-linking causes a concentration of the light active
material at
the first region and a concentration of the polymer at the second region.
In accordance with another aspect of the present invention, a method is
provided
for making a light emitting device. The inventive steps include providing a
bottom substrate, with a bottom electrode over the bottom substrate. An
emissive
layer is disposed over the bottom electrode. The emissive layer includes a
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mixture of a dispersed OLED particulate in a monomer fluid carrier. The
monomer is selectively polymerized causing the OLED particulate to concentrate
in emissive regions and the polymerized monomer to concentrate in
polymerization regions.
In accordance with another aspect of the invention, a method is provided for
making a light emitting device. A bottom substrate is provided and a bottom
electrode provided over the bottom substrate. An emissive layer comprising a
mixture including an emissive/more-conductive material and a non-emissive/less-
conductive material is disposed over the bottom substrate. The mixture is
selectively patterned causing the emissive/more-conductive material to
concentrate in emissive regions and the non-emissivelless-conductive material
to
concentrate in non-emissive regions.
BRIEF DESCRIPTION OF THE DRAWINGS:
Figure 1 illustrates an embodiment of the inventive thin, lightweight,
flexible,
bright wireless display having components capable of being manufactured by the
inventive display fabrication method, showing the simultaneous display of
mapped hyperlinked content, a videophone stream and a broadcast TV stream;
Figure 2 illustrates a particle of OLED material for being dispersed in a
carrier
fluid in accordance with the inventive display fabrication method;
Figure 3 illustrates an inventive microcapsule comprised of an internal phase
of
OLED material encapsulated within a polymer shell;
Figure 4 illustrates an inventive bipolar microcapsule comprised of an
internal
phase of OLED material encapsulated within a polymer shell;
Figure 5 illustrates an inventive microcapsule comprised of a first
microcapsule
including an internal phase of OLED material and magnetic material, along with
a
mixture of electrolyte and uncured monomer, all encapsulated within a polymer
shell;
Figure 6 illustrates an inventive microcapsule comprised of an internal phase
of
OLED material encapsulated within a double-wall shell, each wall having a
31
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composition selected fox imparting a desired electrical, optical, magnetic
andlor
mechanical property to the microcapsule;
Figure 7 illustrates an inventive microcapsule comprised of an internal phase
consisting of a mixture of OLED material with other components so as to tailor
the electrical, optical, magnetic andlor mechanical property of the
microcapsule;
Figure 8 illustrates an inventive microcapsule comprised of a first
microcapsule
including an internal phase comprised of an OLED material, and a corrosion
barrier material, all encapsulated within a polymer shell;
Figure 9 illustrates an inventive microcapsule comprised of a multi-walled
microcapsule structure wherein layers of corrosion barrier material are
encapsulated within polymer shells with an internal phase of OLED material;
Figure 10 illustrates an inkjet-type or other nozzle fabrication method for
forming
a layer of OLED microcapsules dispersed within a light curable monomer
carrier;
Figure I 1 illustrates a layer of OLED microcapsules fixed within a cured
monomer barrier disposed between a top electrode and a bottom electrode;
Figuxe 12 illustrates sealed fabrication stations for forming a barrier
protected
OLED microcapsule display stratum;
Figuxe I3 illustrates an inventive display fabrication line using modular
stations
for forming various stratum of a thin, lightweight, flexible wireless display;
Figuxe 14 illustrates a highly organized OLED microcapsule structure formed in
accordance with the inventive OLED device fabrication method;
Figuxe 15 illustrates a chain structure of OLED microcapsules formed in
accordance with the inventive OLED device fabrication method;
Figure 16 illustrates a full color OLED display formed in accordance with the
inventive OLED device fabrication method;
Figure 17 illustrates a layer of conductive microcapsules for forming an
electrode
layer in accordance with the inventive device fabrication method;
Figure 18 illustrates the formation of OLED microcapsule chains formed on an
electrode layer;
Figure 19 illustrates the formation of OLED rnicrocapsule chains formed
between
top and bottom electrode layers;
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Figure 20 illustrates the formation of OLED microcapsule chains within a cured
carrier for forming a corrosion barrier;
Figure 21 illustrates a full color display formed in accordance with the
inventive
OLED device fabrication method;
Figure 22 illustrates step one of an embodiment of the inventive OLED device
fabrication method;
Figure 23 illustrates step two of an embodiment of the inventive OLED device
fabrication method;
Figure 24 illustrates step three of an embodiment of the inventive OLED device
fabrication method;
Figure 25 illustrates step four of an embodiment of the inventive OLED device
fabrication method;
Figure 26 illustrates step five of an embodiment of the inventive OLED device
fabrication method;
Figure 27 illustrates step six of an embodiment of the inventive OLED device
fabrication method;
Figure 28 shows a magnetically reactive OLED microcapsule for forming a
capacitor OLED microcapsule with the aligning field turned off;
Figure 29 shows a magnetically reactive OLED microcapsule for forming a
capacitor OLED microcapsule with the magnetic aligning field turned on with
uncured electrolyte mixture;
Figure 30 shows a magnetically reactive OLED microcapsule for forming a
capacitor OLED microcapsule with the magnetic aligning field turned on with
cured electrolyte mixture;
Figure 31 shows a pixel comprised of a chain of capacitor OLED being charged
by a charging voltage;
Figure 32 shows a pixel comprised of a chain of capacitor OLED being triggered
for light emission by a trigger voltage;
Figure 33 shows OLED microcapsules randomly dispersed within a fluid but
hardenable carrier fluid;
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Figure 34 shows OLED microcapsule chains aligned within an applied aligning
field formed within unhardened carrier fluid;
Figure 35 shows OLED microcapsule chains aligned within an applied aligning
field held in alignment within hardened carrier;
Figure 36 shows the OLED microcapsule structure shown in Figure 35 with a
drive voltage applied and light being emitted from the OLED microcapsule
chains;
Figure 37 illustrates a method for forming an OLED particulate having a hole
transport layer and an electron transport layer;
Figure 38 illustrates a method for forming an encapsulated OLED particulate;
Figure 39 illustrates a first step in forming a mufti-layered OLED
particulate;
Figure 40 illustrates a second step in forming a mufti-layered OLED
particulate;
Figure 41 illustrates a third step in forming a mufti-layered OLED
particulate;
Figure 42 schematically shows a full-color OLED display constructed in
accordance with the present invention, and having a dichromatic display layer
for
improving the display contrast, power efficiency and for providing display
viewing in bright sunlight;
Figure 43 schematically shows the full-color OLED display shown in Figure 42,
with the dichromatic pixels oriented for reflecting emitted OLED light;
Figure 44 schematically shows the full-color OLED display shown in Figure 42,
showing the relative strength of reflected light depending on the dichromatic
pixel
orientations;
Figure 45 shows magnetically-active OLED microcapsules randomly dispersed
within a fluid but hardenable carrier fluid along with desiccant particulate;
Figure 46 shows the magnetically-active OLED microcapsule chains aligned
within an applied magnetic aligning field within the unhardened carrier fluid;
Figure 47 shows the magnetically-active OLED microcapsule chains aligned
within the applied magnetic aligning field held in position within the
hardened
carrier;
Figure 48 shows the magnetically-active OLED microcapsule structure with light
being emitted from the OLED microcapsule chains;
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Figure 49 schematically illustrates a full color OLED display having high
intensity visible light display layers and an infrared display layer;
Figure 50 shows an OLED display layer and a liquid crystal display layer;
Figure 51 shows an inventive OLED display fabricated with thin films of
organic
material with photodetection elements and photodetection pixel elements;
Figure 52 shows an OLED microcapsule wherein the shell is slightly less
conductive than the encapsulated OLED material;
Figure 53 shows an OLED microcapsule wherein the OLED material is
encapsulated along with an electrolyte and a magnetic inner microcapsule
having
an electrically insulative shell;
Figure 54 shows an OLED microcapsule wherein the OLED material and the hole
transport material are contained in solution within a conductive shell;
Figure 55 shows the OLED microcapsules shown in Figure 54 including a
magnetically active material and color dye in the inner phase and heat
meltable
material in the shell;
Figure 56 illustrates the OLED microcapsule shown in Figure 54 used for
creating
a general lighting or display back lighting OLED device;
Figure 57 illustrates a transparent, flexible OLED display fabricated for use
as
part of a vehicle windshield;
Figure 58 is a block diagram showing the basic components of an active
windshield display system using an OLED display;
Figure 59 illustrates an OLED light emissive element;
Figure 60 shows the OLED light emissive element having a conventional light
bulb form factor;
Figure 61 illustrates an OLED device fabricated using light emissive layers
and
light detecting layers;
Figure 62 illustrates stereoscopic goggles having OLED device elements;
Figure 63 illustrates a flexible OLED display having a curvature that
compensates
for the human eye's range of motion;
Figure 64 illustrates a flexible OLED display having optical lens elements for
focusing emitted light at the appropriate physical location within a human
eye;
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Figure 65 illustrates a wraparound visor having a curved, flexible OLED
display
and speakers;
Figure 66(a) illustrates a wall of a house having an inventive OLED display
window, the window being driven so as to be transparent with trees outside the
house visible through the window;
Figure 66(b) illustrates the wall of a house having the inventive OLED display
window, the window being driven so as to display multiple simultaneous video
stream including video phone communication, Internet web page and a television
program;
Figure 66(c) illustrates the wall of a house having the inventive OLED display
window, the window being driven so as to be a mirror;
Figure 67(a) illustrates the use of an inventive flexible large format display
as part
of a camouflage system for a vehicle, such as a military tank;
Figure 67(b) illustrates the camouflage system shown in Figure 67(a) wherein
the
display area has a curved viewing area;
Figure 67(c) illustrates the use of an inventive flexible clothing display as
part of a
camouflage system for a person;
Figure 67(d) shows the inventive clothing camouflage system shown in Figure
67(b) in use;
Figure 68(a) shows the use of flexible, lightweight solar panels as a sunlight-
to-
energy system fox powering an aircraft, such as a military observation drone;
Figure 68(b) is a block diagram illustrating some system elements of the
military
observation drone shown in Figure 68(a);
Figure 69 illustrates an embodiment of the inventive light active device
showing a
semiconductor particulate randomly dispersed within a conductive carrier;
Figure 70 illustrates an embodiment of the inventive light active device
showing
the semiconductor particulate aligned between electrodes;
Figure 71 illustrates an embodiment of the inventive light active device
showing
semiconductor particulate and other performance enhancing particulate randomly
dispersed within the conductive carrier material;
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Figure 72 illustrates an embodiment of the inventive light active device
showing
different species of organic light active particulate dispersed within a
carrier
material;
Figure 73 illustrates an organic light active particle formed from a polymer
blend;
Figure 74 illustrates the polymer blend organic light active particulate
dispersed
within a conductive carrier;
Figure 75 illustrates the polymer blend organic light active particle showing
light
active sites;
Figure 76 illustrates a polymer blend organic light active particulate having
a field
attractive constituent for aligning the particle in an aligning field;
Figure 77 illustrates composite microcapsules containing multilayered organic
light active particles, each having a different light wavelength emission and
turn-
on voltage;
Figure 78 illustrates another composite microcapsule containing multilayered
organic light active particles,, at least one having a field attractive
constituent;
Figure 79 illustrates three light emitting microcapsule species, each species
having a turn-on voltage controlled by the internal phase composition and the
encapsulating shell composition;
Figure 80 illustrates an embodiment of the inventive voltage controlled light
active device showing the composite microcapsule particulate randomly
dispersed
within a carrier;
Figure 81 illustrates an embodiment of the inventive voltage controlled light
active device showing the composite microcapsule particulate aligned between
electrodes;
Figure 82 illustrates the retinal response of the human eye to wavelengths of
light
in the visible spectrum;
Figure 83 illustrates the inventive primary color burst driving method for
producing a perceived full color image by the rapid and sequential bursts of
primary colored light emission;
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Figure 84 illustrates the inventive retinex burst driving method for producing
a
perceived full color image by the rapid and sequential bursts of colored light
emission;
Figure 85 illustrates the inventive adjusted color burst driving method for
producing a perceived full color image by the rapid and sequential bursts of
adjusted colored light emission;
Figure 86 is a flow chart showing the steps of the inventive method for
forming a
multilayered organic light active material particulate;
Figure 87 illustrates a layered organic light active material particulate
formed by
the commingling of a particle of hole transport material with a particle of
emissive
layer material;
Figure 88 illustrates the inventive method of forming a layered organic light
active material particulate from a hole transport constituent and an emissive
layer
constituent;
Figure 89 illustrates a multi-layered organic light active material
particulate
formed by the commingling of a layered particle of hole transportiemissive
layer
material with a particle of electron transport material;
Figure 90 illustrates the inventive method of forming a mufti-layered organic
light
active material particulate from a hole transport/emissive layer constituent
and an
electron transport constituent;
Figure 91 illustrates a layered organic light active material particulate
formed by
the commingling of a particle of blocking material with a particle of electron
transport material;
Figure 92 illustrates the inventive method of forming a layered organic light
active material particulate from a blocking constituent and an electron
transport
constituent;
Figure 93 illustrates a layered organic light active material particulate
formed by
the commingling of a particle of emissive layer material with a particle of
hole
transport material;
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Figure 94 illustrates the inventive method of forming a layered organic light
active material particulate from an emissive layer constituent and a hole
transport
constituent;
Figure 95 illustrates a multi-layered organic Iight active material
particulate
formed by the commingling of a layered particle of blockingielectron transport
material with a layered particle of emissive layer/hole transport material;
Figure 96 illustrates the inventive method of forming a mufti-Layered organic
light
active material particulate from a blocking/electron transport constituent and
a
hole transportlemissive layer constituent;
Figure 97 illustrates a layered organic light active material particulate
formed by
the commingling of a particle of field attractive material with a particle of
electron
transport material;
Figure 98 illustrates the inventive method of forming a layered organic light
active material particulate from a field attractive constituent and an
electron
transport constituent;
Figure 99 illustrates a layered organic light active material particulate
formed by
the commingling of a particle of emissive layer material with a particle of
hole
transport material;
Figure 100 illustrates the inventive method of forming a layered organic light
active material particulate from an emissive layer constituent and a hole
transport
constituent;
Figure 101 illustrates a mufti-layered organic light active material
particulate
formed by the commingling of a layered particle of field attractive/electron
transport material with a layered particle of emissive Iayerlhole transport
material;
Figure 10~ illustrates the inventive method of forming a mufti-layered organic
Light active material particulate from a field attractive/electron transport
constituent and a hole transportlemissive layer constituent;
Figure 103 is a cross section of a coated cathode fiber having a blocking
layer
formed on the cathode fiber and an electron transport Layer formed on the
blocking Layer;
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Figure 104 is a cross section of a coated anode fiber having a hole transport
layer
formed on the anode fiber and an emissive layer formed on the hole transport
layer;
Figure 105 illustrated the coated cathode fiber and the coated anode fiber
twisted
together to form an emissive fiber;
Figure 106 shows a method for coating an electrode wire with organic light
active
device material;
Figure 107 is a schematic view of a fabrication line utilizing the inventive
OLED
particulatefconductive carrier mixture;
Figure 108 shows the step of printing an electrode pattern on a polymer sheet
substrate;
Figure 109 illustrates the expanded gap distance between electrodes in
accordance
with the present invention;
Figure 110 illustrates a single layered mufti-color pixel in accordance with
the
present invention;
Figure 111 illustrates a prior art OLED device;
Figure 112 illustrates a prior art OLED device showing a dust particle
creating an
electrical short between electrodes;
Figure 113 illustrates a prior art OLED device showing the degradation of the
organic thin film stack by the ingress of oxygen and water through the
substrates;
Figure 114 is a cross sectional schematic view illustrating the extrusion of
light
active fiber having aligned OLED particulate;
Figure 115 is a perspective schematic view illustrating the extrusion of light
active
fiber;
Figure 116 is a cross section of a segment of extruded light active fiber
Figure 117 is a schematic view of the segment of extruded light active fiber
driven
by a voltage applied between electrodes;
Figure 118 is a cross sectional schematic view illustrating an extruded light
active
fiber having a conductive electrode core and a transparent electrode coating;
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Figure 119 is a perspective schematic view illustrating the extrusion of the
Iight
active fiber having a conductive electrode core and a transparent electrode
coating;
Figure 120 illustrates an extruded light active fiber having a conductive
electrode
core and a transparent electrode coating connected with a voltage source;
Figure 121 is a cross sectional schematic view illustrating the extrusion of
light
active ribbon having aligned OLED particulate;
Figure 122 is a perspective schematic view illustrating the extrusion of light
active
ribbon;
Figure 123 is a segment of extruded light active ribbon;
Figure 124 is a cross-sectional view of the segment of extruded light active
ribbon
having wire electrodes incorporated within the ribbon and driven by a voltage
applied between electrodes;
Figure 125 illustrates a light active fiber extrusion and chopping mechanism
for
forming uniform lengths of OLED light active fiber;
Figure 126 illustrates OLED light active fiber randomly dispersed between two
electrodes;
Figure 127 illustrated the OLED light active fibers aligned between the two
electrodes;
Figure I28 illustrates OLED light active fibers randomly dispersed between two
electrodes having a gap distance close to the uniform length of the fibers;
Figure 129 illustrated the OLED light active fibers aligned between the two
electrodes having a gap distance close to the uniform length of the fibers;
Figure 130 illustrates light active fibers woven into carpeting;
Figure 131 illustrates a light active cloth weave;
Figure 132 illustrates a curved large format surround display formed in
accordance with the present invention by tiling length of display sections;
Figure 133 illustrates a method of forming two layer ultra-thin multilayered
OLED fiber by drawing and thinning;
Figure 134 illustrates a method of forming four layer ultra-thin multilayered
OLED fiber by drawing and thinning;
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Figure 135 is a cross sectional view showing a wire having an electron
transport
coating layer;
Figure 136 is a cross sectional view showing a wire having a hole transport
coating layer;
Figure 137 illustrates coated wire intersecting electrodes for forming light
emitting pixels at the intersections;
Figure 138 illustrates the inventive OLED particulatelconductive carrier
mixture
formulated for being formable into useful products through plastic molding
techniques;
Figure 139 illustrates an inventive OLED solid state light having a
conventional
light bulb form factor;
Figure 140 illustrates a step of spray painting a reflective conductive layer
of an
OLED device;
Figure 141 illustrates a step of spray painting an emissive layer of an OLED
device;
Figure 142 illustrates a step of spray painting a transparent electrode of an
OLED
device;
Figure 143 illustrates a step in an inventive method for making a light active
device showing a light active mixture disposed between an x and y electrode
grid;
Figure 144 illustrates another step in the inventive method for making a light
active device, showing a polymerizationlmigration step;
Figure 145 illustrates another step in the inventive method for making a light
active device, showing an aligning step;
Figure 146 illustrates another step in the inventive method for making a light
active device, showing a controlled pixelated light emission;
Figure 147 illustrates a step in an inventive method for making a light active
device, showing a bottom substrate having a bottom electrode pattern formed
thereon;
Figure 148 illustrates another step in the inventive method for making a light
active device, showing a light active mixture disposed at a light active layer
over
the bottom electrode pattern;
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Figure 149 illustrates another step in the inventive method for making a light
active device, showing the patterning of the light active layer by irradiation
through a mask;
Figure I50 illustrates another step in the inventive method for making a light
active device, showing the migration of light active material into light
active
regions;
Figure ISI illustrates the composition of constituents in a mufti-color light
active
mixture;
Figure 152 illustrates a step in an inventive method for making a mufti-color
light active device, showing a mufti-color light active mixture disposed over
a
patterned bottom electrode grid;
Figure 153 illustrates a step in the inventive method for making a mufti-color
light
active device, showing the selective patterning of one of the color light
active
regions;
Figure 154 illustrates a step in the inventive method for making a mufti-color
light
active device, showing the patterned color light active regions;
Figure 155 illustrates a full-color light active device having red, green and
blue
side-by-side patterned color light active regions;
Figure 156 illustrates a step in an inventive method for making a pixilated
light
active device; showing a mixture of light active material disposed over a
patterned
bottom electrode grid;
Figure 157 illustrates another step in the inventive method for making a
pixilated
light active device, showing selective patterning through a pixel grid mask;
Figure 158 illustrates another step in the inventive method for making a
pixilated
light active device, showing the migration of light active material to pixel
regions;
Figure 159 illustrates the composition of constituents in a light active
device
having pixels and conductive pathways formed by a self-assembly process;
Figure 1&0 illustrates a step in an inventive method for making a light active
device having pixels and conductive pathways formed by a self-assembly
process;
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Figure 161 illustrates another step in the inventive method for making a light
active device by self assembly, showing the selective patterning of the
conductive
pathways by irradiation through a mask;
Figure 162 illustrates another step in the inventive method far making a light
active device by self assembly, showing the patterned conductive pathways;
Figure 163 illustrates another step in the inventive method for making a light
active device by self assembly, showing the selective patterning of pixel
regions
by irradiation through a mask;
Figure 164 illustrates another step in the inventive method for making a light
active device by self assembly, showing the patterned pixel regions and
conductive pathways;
Figure 165 schematically illustrates a light active device made by self-
assembly,
showing emissive/more conductive zones, non-emissivelmore conductive zones
and non-emissiveilass conductive zones;
Figure 166 illustrates a cubic volume of a randomly dispersed light active
material
in a light polymerizable monomer carrier; and
Figure 167 illustrates the cubic volume shown in Figure 166, showing the light
active material and polymerized carrier after holographic patterning using an
interference pattern generated by laser beams.
DETAILED DESCRIPTION OF THE INVENTION:
For purposes of promoting an understanding of the principles of the invention,
reference will now be made to the embodiments illustrated in the drawings and
specific language will be used to describe the same. It will nevertheless be
understood that no limitation of the scope of the invention is thereby
intended,
there being contemplated such alterations and modifications of the illustrated
device, and such further applications of the principles of the invention as
disclosed herein, as would normally occur to one skilled in the art to which
the
invention pertains.
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Figure 1 illustrates an embodiment of the inventive thin, lightweight,
flexible,
bright wireless display having components capable of being manufactured by the
inventive display fabrication method, showing the simultaneous display of
mapped hyperlinked content, a videophone stream and a broadcast TV stream.
Figure 1 illustrates an embodiment of an inventive thin, lightweight,
flexible,
bright, wireless display showing the simultaneous display of three received
display signal. The wireless display utilizes a simple DSP and transceiver. It
has a
unique printed battery power supply and printed user-input mechanism.
The inventive thin, lightweight, flexible, bright, wireless display includes a
flexible substrate to provide a support structure upon which components can be
manufactured by a fabrication method. As described in the co-owned U5 Patent
Application Serial Number 101234,302,entitled "A Thin, Lightweight, Flexible,
Bright, Wireless Display", the disclosure of which is incorporated by
reference
herein, a unique and effective method for transmitting display information to
a
single or multiple displays enables such displays to not have to have
substantial
onboard storage or processing power. In accordance with this aspect of the
invention, the energy drain, bulk, weight and cost normally associated with
such
devices is avoided, and the durability and convenience of the display is
increased.
Further, as shown schematically in Figure l, multiple streams of display
information can be simultaneously received and displayed. For example,
broadcast video content such as a television program may be shown at a first
portion of the display, personalized video content, such as a videophone
2~ conversation may be shown at a second portion and a web page, including
mapped hyperlink content, may be shown at a third portion. Most of the
processing, networking, signal tuning, data storage, etc., etc., that it takes
to create
such a set of displayed content streams is not performed by the inventive
wireless
display. Other devices, such as a centralized computer, A/V or gateway device
perform these functions thus allowing the opportunity for the inventive
display to
have tremendous mobility and convenience.
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Figure 1 illustrates an embodiment of the inventive thin, lightweight,
flexible,
bright wireless display having components capable of being manufactured by the
inventive fabrication method, showing the simultaneous display of mapped
hyperlinked content, a videophone stream and a broadcast TV stream. In
accordance with the present invention, a thin, lightweight, flexible, bright
wireless
display is obtained having components capable of being manufactured by the
inventive fabrication method. The present invention enables a low cost,
flexible,
robust, full color video display to be obtained. This wireless display is
capable of
receiving multiple display information signals and displaying the simultaneous
screens of the received display information in re-configurable formats. A
relatively simple signal receiving and processing circuit, using, for example,
a
digital signal processor such as those available from Texas Instruments, Texas
or
Oxford Microdevices, Connecticut, enables multiple video and still image
screens
to be displayed. An inventive manufacturing method described herein and in the
co-owned patent application entitled "Printer and Method for Manufacturing
Electronic Circuits and Displays" (incorporated by reference herein) enables
the
inventive wireless display to be fabricated at low cost and with the
advantageous
features described herein. As will be described in more detail, a flexible
substrate
provides a support structure upon which components can be manufactured by a
fabrication method. A display stratum includes light emitting pixels for
displaying information. The light emitting pixels are formed, by printing or
otherwise forming a pixel layers) of light-emitting conductive polymer. An
electronic circuit stratum includes signal transmitting components for
transmitting
user input signals to a display signal generating device for controlling
display
information transmitted from the display signal generating device. Signal
receiving components receive the display information transmitted from the
display signal- generating device. Display driving components drive the
display
layer according to the received display information. A user input stratum
receives
user input and generates the user input signals. A battery stratum provides
electrical energy to the electronic circuit stratum, the user input stratum
and
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display stratum components. The signal receiving components may include first
radio frequency receiving components for receiving a first display signal
having
first display information carried on a first radio frequency and second radio
frequency receiving components for receiving a second display signal having
second display information carried on a second radio frequency. In this
manner,
two or more simultaneously transmitted video displays can be simultaneously
displayed. The display driving components may include signal processor
components for receiving the first display signal and the second display
signal and
generating a display driving signal for simultaneously displaying the first
display
information at a first location on the display stratum and the second display
information at a second location on the display stratum. At least some of the
components in the battery, display, user input and electronic circuit stratums
can
be formed by printing electrically active material to form circuit elements
including resistors, capacitors, inductors, antennas, conductors and
semiconductor
devices.
The inventive thin, lightweight, wireless display includes OLAM fabrication,
such
as that described herein. In accordance with the present invention,
microcapsule
10 or particulate are randomly dispersed within a monomer carrier fluid 12
that is
injected or otherwise disposed between two electrodes 14. Generally, the term
particulate can refer herein to particles of material or microcapsules 10, and
vice-
versa. The microcapsules 10 may include additives that impart Theological
andlor
phoretic properties. The microcapsules 10 form chains between the electrodes
14
when a voltage is applied. Holding the voltage to keep the chains formed, the
carrier fluid 12 is polymerized and the OLAM microcapsule chains locked into
alignment between the electrodes 14. The thus formed OLAM pixels emit light
(or detect or convert light into electricity). The problem of contamination of
the
OLAM material is the major factor limiting the display life span, and thus far
has
been a bar to commercial success. The inventive fabrication method results in
the
moisture sensitive OLAM material being protected by the microcapsule shell and
the cured carrier 12. The pixel alignment is automatic, since the microcapsule
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chains are formed only between the electrodes 14. This pixel array structure
also
greatly limits cross talk between pixels and the optical properties of the
cured
monomer can be controlled to improve contrast, display brightness,
transparency,
etc.
Solar cell components or layers can be used to "recycle" the energy emitted by
the
OLED emitters. Some of the emitted and ambient light energy impinges on the
solar cells and generate electricity. This, along with the inventions
described
herein and the sheet battery described in the above-referenced co-owned Patent
Applicant entitled "Printer and Method for Manufacturing Electronic Circuits
and
Displays", can enable lightweight, relatively inexpensive, dichromatic
newspapers
(as described herein in Figure 1) that recharge in sunlight (or even indoor
ambient
light) to enable full-color emissive video display.
Figure 2 illustrates a particle of OLED material for being dispersed in a
carrier
fluid 12 in accordance with the inventive display fabrication method. A
typical
OLED organic stack consists of a layer of hole transport material and a layer
of
electron transport material. In the conventional art, these layers are formed
by
spin coating, vacuum deposition or inkjet printing. In accordance with the
present
invention, the OLED material is provided as particulate dispersed within a
carrier
12 material. The carrier 12 material with the dispersed particulate is
disposed
between electrodes 14. Electrical potential applied to the electrodes 14
causes
light emission to occur within the OLED particulate. In accordance with the
present invention, the OLED phenomenon can be used to create general or
specialty lighting devices, monochrome or color displays, stereoscopic vision
aids, digital maps and newspapers, advanced vehicle windshields and the like.
Also, the particulate can be organic light active material ("OLAMTM") that is
capable of generating a flow of electrons in response to impinging light
energy.
This phenomenon can be used to create photodetectors, cameras, solar cells and
the like. In this application, where appropriate, the term OLED can mean a
light
emissive or a light detective material configuration.
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Figure 3 illustr ates an inventive microcapsule 10 comprised of an internal
phase
of OLAM material encapsulated within a polymer shell. To create a path of
least
resistance through the OLED material, the shell composition is selected to be
less
conductive than the OLED material.
Figure 4 illustrates an inventive electro-statically active microcapsule 10
comprised of an internal phase of OLED material encapsulated within a polymer
shell. The shell is composed of a material that can be oriented by the
application
of an electric field. The electrical properties of the shell enable the
microcapsules
10 to be aligned into a desired formation within a fluid carrier 12 in
response to an
applied electric field.
Figure 5 illustrates an inventive microcapsule 10 comprised of a first
microcapsule 10 including an internal phase of OLED material and magnetic
material, along with a mixture of electrolyte and uncured monomer, all
encapsulated within a polymer shell. The magnetic properties of the magnetic
material enable the microcapsules 10 to be aligned into a desired formation
within
a fluid carrier 12 in response to an applied magnetic field.
Figure 6 illustrates an inventive microcapsule 10 comprised of an internal
phase
of OLED material encapsulated within a double-wall shell, each wall having a
composition selected for imparting a desired electrical, optical, magnetic
and/or
mechanical property to the rnicrocapsule. In accordance with the present
invention, the OLED particulate comprises microcapsules 10. For example, the
microcapsule 10 includes an internal phase and a shell that is composed of
material selected according to a desired combination of electrical,
mechanical,
optical and magnetic properties. The internal phase andlor the shell may
include
the OLED material. The internal phase and/or the shell may also include a
field
reactive material. Depending on the OLED fabrication method and the desire
OLED characteristics, the field reactive material may be an electrostatic
material
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and/or a magnetically reactive material. The microcapsule 10 composition may
be effective for enabling a "self healing" capability of the fabricated OLED
device. In this case, the microcapsule 10 includes a composition that causes
the
microcapsule 10 to rupture if electrical energy above a threshold is applied
to the
microcapsule. A heat meltable material that heats up when electrical energy
above a threshold is applied can be incorporated as the microcapsule shell.
For
example, if a particular microcapsule 10 ends up positioned so that during use
of
the OLED device it becomes a short between the electrodes 14, or if the
microcapsule 10 is adjacent to a dust particle or other foreign inclusion,
creating
such a short, when an electric potential is applied between the electrodes 14,
energy exceeding a predetermined threshold will pass through the microcapsule
10 causing the capsule to rupture and disconnect the short. By this
construction,
the microcapsule 10 is automatically removed from the path of conduction of
electrical energy in the event of a short.
Figure 7 illustrates an inventive microcapsule 10 comprised of an internal
phase
consisting of a mixture of OLED material with other components so as to tailor
the electrical, optical, magnetic and/or mechanical property of the
microcapsule.
The other components can be field reactive, such as magnetic or electro-
statically
reactive materials for imparting orientation and aligning properties. Heat
expandable materials can be included to provide the microcapsule 10 with the
ability to burst or otherwise change shape or electrical characteristic in
response to
an electrical short to disconnect the microcapsule 10 and overcome the
electrical
short. Colorants, such as dyes and colored particles can be included to tune
the
light emitted from the microcapsule. Desiccant and/or scavenger material can
be
included to provide protection against contamination of the OLED material.
Figure 8 illustrates an inventive microcapsule 10 comprised of a first
microcapsule 10 including an internal phase comprised of an OLED material, and
a corrosion barrier material, all encapsulated within a polymer shell. In
accordance with this aspect of the invention, the microcapsule shell andJor
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internal phase may include a composition effective to provide a barrier
against
degradation of the OLED material. The OLED microcapsules 10 are dispersed
within a carrier fluid 12. This carrier fluid 12 also provides a barrier
against the
intrusion of substances which degrade the OLED material.
Figure 9 illustrates an inventive microcapsule 10 comprised of a mufti-walled
microcapsule 10 structure wherein layers of barrier material are encapsulated
within polymer shells with an internal phase of OLED material. As in the
microcapsule 10 shown in Figure 7, within the shell of the microcapsule 10
other
components can be included that are field reactive, such as magnetic or
electro-
statically reactive materials for imparting orientation and aligning
properties.
Heat expandable materials can be included to provide the microcapsule 10 with
the ability to burst in response to an electrical short to disconnect the
microcapsule 10 and overcome the electrical short. Colorants, such as dyes and
colored particles can be included to tune the light emitted from the
micracapsule.
Desiccant, getter and scavenger material can be included to provide protection
against contamination of the OLED material.
Figure 10 illustrates an inkjet-type or other nozzle 36 fabrication method for
forming a layer of OLED microcapsules 10 dispersed within a light curable
monomer carrier 12. OLED microcapsules 10 dispersed in an uncured monomer
carrier fluid 12 can be utilized with inkjet printing technology to create a
film of
OLED microcapsules 10 contained with flexible cured monomer. The inkjet-type
or other nozzle fabrication technique, such as slot-die, can be utilized to
form
controlled OLED deposition, with the OLED contained within a curable carrier
12. As is described elsewhere herein, desiccant particulate can be included
within
the carrier 12 to enhance the protection of the OLED material.
Figure 11 illustrates a layer of OLED microcapsules 10 fixed within a cured
monomer barrier disposed between a top electrode 14 and a bottom electrode 14.
The cured monomer and the shell of the microcapsules 10 provide a barrier to
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contamination from water vapor and oxygen. The OLED device can be
constructed of suitably chosen materials so that the carrier material 12 is
relatively
less electrically conductive than the OLED particulate, this ensures that the
OLED
particulate offers a path of less electrical resistance than the carrier
material 12.
Thus, the electric potential applied to the electrodes 14 will pass through
the
carrier material 12, which has some electrical conductivity, and through the
OLED particulate, which has relatively higher electrical conductivity. In this
way, the preferred path of electrical conduction is through the OLED
particulate.
Likewise, the shell of the OLED microcapsules 10 is relatively less
electrically
conductive than the OLED material itself, so that the OLED material offers a
path
of less electrical resistance than the shell. Field-attractive microcapsules
10
containing OLED material randomly dispersed within a monomer carrier fluid 12
are injected or otherwise disposed between two electrodes 14. The
microcapsules
10 may include additives that impart electro or magneto rheological-type
properties. When used for a pixilated display layer, the microcapsules 10 form
chains between the electrodes 14 when an aligning field is applied. Holding
the
aligning field to keep the chains formed, the carrier fluid 12 is polymerized
and
the OLED microcapsule chains are locked into alignment between the electrodes
14.
The problem of contamination of the OLED material is the major factor limiting
the display life span, and thus far has been a bar to commercial success. The
inventive fabrication method results in the moisture and oxygen sensitive OLED
material being protected by the microcapsule shell and the cured carrier 12,
and
the pixel alignment is automatic, since the microcapsule chains are formed
only
between the electrodes 14 or where the aligning field is applied. This pixel
array
structure also greatly limits cross talk between pixels and the optical
properties of
the cured carrier 12 can be controlled to improve contrast, display
brightness,
transparency, etc. The OLED particulate in a carrier 12 disposed between two
or
more electrodes 14 can be utilized to create roll-to-roll sheets of displays
or lights,
used as "filament" in a light bulb, used to form solar cells, solar cell
housing
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shingles, light detectors, cameras, vision aides, heads-up display windshields
and
the like. This OLAM construction can even be formed as fibers for light
emitting
flooring, wall coverings, specialty lighting, clothing, shoes, building
materials,
furniture, etc. The OLAM material can be injection molded, or otherwise formed
using known polymer fabrication methods.
Figure 12 illustrates sealed fabrication stations 22 for forming a barrier
protected
OLED microcapsule display stratum. The microcapsules 10 are dispersed in a
carrier fluid 12. The upper and lower plates 16 control the intensity of the
attraction toward and/or between the flexible substrate 24 and sheet electrode
14.
Seals 18 keep out water and air, using a vacuum airlock. The curing station 20
cures the carrier fluid 12 into a flexible water and oxygen barrier. The
microcapsules 10 can be for forming emitters, detectors, various electronic
circuit
elements (as described in the referenced co-owned patent application). The
microcapsules 10 may also be for adding other mechanical (structure,
expansive,
meltable, desiccant, etc.), optical (reflective, diffusive, opaque, colorant,
etc.),
electrical (conductive, resistive, semi-conductive, insulative, etc.). The
upper and
lower plate 16s are controlled to vary the attractive andlor aligning field
and
create controlled accumulations and alignments of the microcapsules 10. The
viscosity of the fluid can also be controlled to control the accumulations of
microcapsules 10 (for three-dimensional buildup, control spread of pixels,
etc.).
As an example, lower viscosity carrier fluid 12 with an agitator may be
preferred.
There can be, for example, two simultaneously applied aligning fields,
magnetic
and electrostatic. A mix of microcapsules 10 can be dispersed, (e.g.,
magnetically
and conductive OLED microcapsules 10 and electro-statically conductive
insulators fox creating a more controllable path of least resistance).
Figure 13 illustrates an inventive display fabrication line using modular
printers
for forming various stratum of a thin, lightweight, flexible wireless display.
Display fabrication line uses mix of different fabrication stations 22.
Examples
of fabrication stations 22 can be found in co-owned US Patent Application
Serial
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No. 10/234,301 entitled "Printer and Method for Manufacturing Electronic
Circuits and Displays". The various layers of a display include battery,
electronic
circuit, user input and display stratums are foamed at different fabrication
stations
22. In accordance with the present invention, fabrication stations 22 for
forming
an OLED light emissive device is provided. A top electrode 14 and a bottom
electrode 14 define a gap there between. Disposed Within the gap, field
reactive
OLED particulates are randomly dispersed within a fluid carrier 12. Depending
on the device being fabricated, an aligning field may be applied between the
top
electrode 14 and the bottom electrode 14 to form a desired orientation of the
field
reactive OLED particulate within the fluid carrier 12 between the top
electrode 14
and the bottom electrode 14. The carrier 12 comprises a hardenable material,
such as a light-curable liquid monomer. The carrier 12 is cured to form a
hardened carrier 12 for maintaining the desired orientation of the field
reactive
OLED particulate within the hardened carrier 12. The OLED particulate may
comprise a bipolar OLED microcapsule 10 or other OLED-based structure that is
capable of forming chains between the electrodes 14.
Depending on the quality of the barrier created by the inventive fabrication
method, there may be no need for additional barrier layers 30 other than
substrates
24 since cured carrier 12 and microcapsule shells protect OLED material from
water vapor and oxygen. Alternatively, additional barrier layers 30, including
monomer, polymer, ceramic or thin metal layers can be included in the
structure
as needed to protect the OLED material from contamination. Each color layer
can
be built on the previous by fabrication method. The conductors 26 that make up
the pixel electrodes 14 can also be used to fabricate the OLED microcapsule 10
structure. In this case the substrate 24 and pixel electrode 14 grid become
integral
parts of the completed OLED device. Further, the electric field created by
applying voltage to the electrodes 14 can be used to align the OLED
microcapsules 10 in chains as shown elsewhere herein. The mechanism for this
alignment is similar to the phenomenon that causes electro-rheological fluids
to
form chains within a carrier fluid 12. In this case, the OLED microcapsule 10
or
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the OLED particle itself includes the appropriate material component that
enables
the electro-rheological effect. In addition, or alternatively, magnetic
material can
be employed with a magnetic field being applied as the aligning field. The
light
emitted from the OLED material when energized by the applied voltage can be
used to cure the monomer surrounding the microcapsules 10. Thus, the voltage
applied to the electrodes 14 during device fabrication are utilized to form
the pixel
orientation and simultaneously cure the barrier material.
Figure 14 illustrates a highly organized OLED microcapsule 10 structure formed
in accordance with the inventive OLED device fabrication method. Pixels can be
controlled down to the microcapsule 10 size, spaced apart as needed. The
conductive shell having a semi-insulative or semi-conductive electrical
property.
The insulative or semiconductor shell creates a preferred path for the
electron
movement. By controlling the conductivity of the cured carrier fluid 12, the
preferred path can be more pronounced through the OLED material.
Figure 15 illustrates a chain structure of OLED microcapsules 10 formed in
accordance with the inventive OLED device fabrication method. Chains of
microcapsules 10 can be formed encased in a somewhat opaque cured carrier 12,
creating more intense columns of light and defined pixels, or the carrier 12
can be
an optical diffusion layer to create a mixing of light from adjacent pixels
with
electrical cross talk between the pixels reduced or eliminated by the
inventive
OLED device structure). Depending on the desired optical qualities of the
fabricated OLED device, the carrier material can be selected so that it has
optical
properties during use of the OLED device that are transparent, diffusive,
absorptive, and/or reflective to light energy. During the hardening process of
the
carrier, it can be selectively cured so that it is more light transmissive
through the
volume between the top and bottom electrodes and less light transmissive or
more
light absorbing through the volume that is not between the electrodes. With
this
construction, the contrast of the display is improved and ambient light is
absorbed
rather than reflected from the display to reduce glare. Also, depending on the
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composition of the carrier material and characteristic enhancing material
incorporated in it, the selective curing of the carrier fluid can control the
conduction of electrical energy through it. In this way, the volume between
the
pixels is controlled to be less conductive than the volume between the top and
bottom electrodes of each pixel. This mechanism further reduces cross talk
between the pixels. In accordance with the present invention, an OLED device
includes a first electrode 14 and a second electrode 14. The second electrode
14 is
disposed adjacent to the first electrode 14 so that a gap is defined between
them.
An OLED particulate is dispersed within a carrier material 12, which is
disposed
within the gap. When an electric potential is applied to the electrodes 14,
the
electrical energy passes through the carrier material 12 raising the energy
state of
the OLED particulate, resulting in the emission of light. The typical OLED
includes an OLED component that is a hole transport material and an OLED
component that is an electron transport material. In accordance with a
formulation of the inventive microcapsules 10, the shell comprises an OLED
component material that is either the hole transport material or the electron
transport material, and the internal phase of the microcapsule 10 includes the
OLED component material that is the other of the hole transport material or
the
electron transport material. Depending on the desired optical qualities of the
fabricated OLED device, the carrier 12 material can be selected so that it has
optical properties during use of the OLED device that are transparent,
diffusive,
absorptive, and/or reflective to light energy, andlor have such optical
properties
tuned for specific wavelengths of light.
Figure 16 illustrates a full color OLED display formed in accordance with the
inventive OLED device fabrication method. The inventive
microcapsulelparticulate fabrication is used to create a full color emissive
display.
Pixels can be controlled down to the microcapsulelparticulate size, spaced
apart as
needed. The conductive shell can have a semi-conductive, conductive or an
insulative over shell. The composition creates a preferred path for the
electron
movement. By controlling the conductivity of the cured carrier fluid 12, the
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preferred path can be more pronounced. The inventive OLED device includes a
first OLED pixel layer comprised of a first layer electrode 14. A second layer
electrode 14 is disposed adjacent to the first layer electrode 14. A first
layer gap
is defined between the electrodes 14. An OLED particulate is dispersed within
a
carrier 12 and contained within the first layer gap. At least one subsequent
OLED
pixel layer is formed over the first OLED pixel layer. Each subsequent OLED
pixel layer includes a first subsequent layer electrode 14. A second
subsequent
layer electrode 14 is disposed adjacent to the first subsequent layer
electrode 14
defining a second layer gap there between. An OLED particulate in a carrier
material 12 is disposed between the electrodes 14. To achieve a full color
OLED
display, the OLED particulate of the first OLED pixel layer emits light of a
first
wavelength range in response to a drive voltage being applied to the first
layer
electrode 14 and the second layer electrode 14. Each subsequent OLED pixel
layer emits light of a different wavelength range in response to the driving
voltage
applied to the respective electrode 14 pairs so that an RGB color display can
be
formed.
Figure 17 illustrates a layer of conductive microcapsules 10 for forming an
electrode layer in accordance with the inventive device fabrication method.
The
buildup of microcapsule layers may occur in successive fabrication steps. The
conductor 26 may be microencapsulated, or just a field attractive material.
For
example, a ferrous metal powder can be magnetically attracted to form one or
more of the conductors. The OLED microcapsule 10 can be electrostatic or
magnetically attractive. The carrier substrate 24 has to pass the applied
field, and
a second, more robust substrate may be added later, or barrier layers may be
formed as needed. The carrier fluid 12 is heat or light hardenable by energy
emitted from a curing source 28 to lock the microcapsules 10 in place.
Alternatively, the carrier fluid 12 can be a plastic material capable of being
injection molded, or a multi-part mixture such as an epoxy, a conductive
powder
and a hardener.
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Figure 18 illustrates the formation of OLED microcapsule chains formed on an
electrode layer. Conductive pixels can be etched into optomagnetic or
optoelectric coating to improve resolution. Or the location of the pixel that
is
energized can be controlled by light or laser pulse or other mechanism. The
light
curable polymer can be cured to a desired depth to capture the microcapsules
10
that have been attracted, and thus lock in, fox example, a microcapsule chain
having a desired length.
Figure 19 illustrates the formation of OLED microcapsule chains formed between
top and bottom electrode layers. The electrodes 14 can be formed in previous
fabrication steps, and may be attracted by a mechanism other than the
mechanism
that orients the OLED particulate.
Figure 20 illustrates the formation of OLED microcapsule chains within a cured
carrier 12 for forming a corrosion and/or contamination barrier. The substrate
24
upon which the microcapsules 10 a.re printed may be a mufti-layered
composition
of polymer, cured monomer, ceramic and fiber, such as glass, creating a
durable,
flexible substrate 24 that is also a barrier to corrosion for the OLED (as is
the
microcapsule shell and the cured carrier fluid 12). The conductors 26 that
make
up the pixel electrodes 14 can also be used to apply the aligning field used
to
fabricate the OLED microcapsule structure.
Figure 21 illustrates a full color display formed in accordance with the
inventive
OLED device fabrication method. Depending on the quality of the barrier
created
by the inventive fabrication method, there may be no need fox additional
barrier
layers 30 other than substrates 24 since cured carrier 12 and microcapsule
shells
protect the OLED material from water vapor and oxygen. Alternatively,
additional barrier layers 30, including monomer, polymer, ceramic, fiber,
desiccant, getter, scavenger and/or thin metal layers can be included in the
structure as needed to protect the OLED material from contamination. Each
color
layer can be built on the previous, by a fabrication station. The conductors
26 that
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make up the pixel electrodes 14 can also be used to fabricate the OLED
microcapsule structure. In this case, the substrate 24 and pixel electrode
grid
become integral parts of the completed OLED device. The electric field created
by applying voltage to the electrodes 14 can be used to align the OLED
microcapsules 10 in chains as shown elsewhere herein. The mechanism for this
alignment is similar to the phenomenon that causes electro-rheological
particulate
to form chains within a carrier fluid 12. In this case, the OLED microcapsule
10
or the OLED particle itself includes the appropriate material component that
enables the rheological or phoretic effect (i.e., the movement of the OLED
particulate within the carrier). In addition, or alternatively, magnetic
material can
be used with a magnetic field being applied as the aligning field. The light
emitted from the OLED material when energized by the applied driving voltage
can be used to cure the monomer surrounding the microcapsules 10. Thus, the
voltage applied to the electrodes 14 during device fabrication can be utilized
to
form the pixel orientation and simultaneously cure the barrier material.
Figures 22-27 illustrate the steps for forming an OLED device in accordance
with
an embodiment of the present invention. Figure 22 illustrates step one of an
embodiment of the inventive OLED device fabrication method. Step One:
Provide Top and Bottom Flexible Substrates. Step Two: Form Barrier layers 30
on Top and Bottom Flexible Substrates 24 (Figure 23). Step Three: Form Top
and Bottom Electrodes 14 on Barrier layer 30 (Figure 24). Step Four: Fill Void
between Top and Bottom Electrode 14 with OLED microcapsules 10 dispersed in
uncured carxier fluid 12 (Figure 25). Step Five: Apply potential to electrodes
14
to organize OLED microcapsules and/or particulate 10 into chains (Figure 26).
Step Six: Cure carrier 12 to lock OLED microcapsule chains between the
electrodes 14 to form pixels (Figure 27). The composition of the OLED
particulate can be selected so that the characteristics of the OLED
particulate
includes an electro or magneto rheological or phoretic characteristic. This
rheological or phoretic characteristic is effective for causing the OLED
particulate
to orient and/or migrate in an applied aligning field.
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Figure 28 shows a magnetically reactive OLED microcapsule 10 for forming a
capacitor OLED microcapsule 10 with the aligning field from an aligning field
source 32 turned off. An OLED microcapsule 10 is formed having a capacitor
capability. An OLED material internal phase is encapsulated within a first
shell.
An electrolyte surrounds the first shell and a second shell encapsulates the
first
shell and the electrolyte. The OLED material internal phase includes a field
reactive material. The field reactive material comprises at least one of a
magnetically reactive material and an electrically reactive material effective
to
orient the OLED microcapsule 10 within an aligning field applied from the
aligning field source 32. By this construction, OLED material and field
attractive
material, such as magnetic material, are microencapsulated within an
electrically
conductive shell, forming an OLED/Mag internal core. The OLED/Mag internal
core is microencapsulated along with a mixture of electrolyte and light
curable
monomer liquid phase within a second electrically conductive shell. The
microcapsule shell material is selected to have the appropriate breakdown
voltage
at which charge conduction occurs. The microcapsules 10 act as capacitor
elements that are, for example, charged up with a charging voltage. A trigger
voltage is then applied when the OLED pixel is to emit light.
Figures 28-30 illustrate the formation of an OLED/Capacitor microcapsule.
OLED material and field attractive material, such as magnetic material, are
microencapsulated within an electrically conductive shell, forming an OLEDIMag
core. The OLED/Mag core is microencapsulated along with a mixture of
electrolyte and light curable monomer liquid phase within a second
electrically
conductive shell. The microcapsule shell material is selected to have the
appropriate breakdown voltage at which charge conduction occurs. Figure 29
shows a magnetically reactive OLED microcapsule 10 for forming a capacitor
OLED microcapsule 10 with the magnetic aligning field turned on with uncured
r
electrolyte mixture. Figure 30 shows a magnetically reactive OLED microcapsule
10 for forming a capacitor OLED microcapsule 10 with the magnetic aligning
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field turned on with cured electrolyte mixture. In accordance with this
composition of the OLED microcapsule, the internal phase comprises OLED
material and a magnetically reactive material disposed within a first shell.
An
electrolyte and a curable fluid material surround the first shell. A second
shell
encapsulates the first shell, the electrolyte and the curable material. In
response to
an applied magnetic field, the position of the first shell is changeable
relative to
the second shell. Upon curing the curable material, the position of the first
shell
relative to the second shell is locked in place. This microcapsule 10
structure can
be used to form capacitors/OLED rnicrocapsules 10 which may be particularly
effective for use in passive matrix displays. Typically, a passive matrix
display is
driven with a relatively high driving energy so that the emission of light by
a
driven pixel is intense. This intensity overcomes the short driving time of
the
pixel (as compared with the more controllable active matrix backplane). This
passive matrix driving scheme results in shorter display life, higher power
consumption and lower display quality. When a charging voltage is applied
(such
as during a charging scan of a passive matrix OLED display grid), the
capacitor
elements of the microcapsule 10 store applied electrical energy. The charging
voltage can be controllably applied to selected pixels and in multiple scans
to vary
the stored charge in the microcapsules 10 associated with each pixel. When a
trigger voltage is applied (during the display writing scan), the OLED
material
emits light in response to the trigger voltage and in a manner dependent on
the
stored charge. With the proper selection of microcapsule 10 materials, an RC
circuit is formed giving the OLED pixel an increased and more controlled light
emission time and intensity.
Figure 31 shows a pixel comprised of a chain of capacitor OLED microcapsules
being charged by a charging voltage. Figure 32 shows a pixel comprised of a
chain of capacitor OLED microcapsules being triggered for light emission by a
trigger voltage. The microcapsules 10 act as capacitor elements that are
charged
up with a charging voltage. A trigger voltage is then applied when the OLED
pixel is to emit light. Alternatively, the charging voltage may just result in
the
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emission of light, but the RC circuit nature of the OLED microcapsule creates
a
longer light emission pulse than the voltage charging pulse, resulting in a
higher
quality passive matrix displayed image.
Figure 33 shows OLED microcapsules 10 randomly dispersed within a fluid but
hardenable carrier fluid 12. A first electrode 14 and a second electrode 14
are
provided defining a gap there between. Within the gap, field reactive OLED
particulate is randomly dispersed within a fluid carrier 12. The electrodes 14
can
be preformed on a substrate, such as glass. Alternatively, one or both grids
of
electrodes 14 can be preformed on a flexible carrier 12 enabling roll-to-roll
manufacturing. The inventive fabrication technology overcomes the last hurdles
to
widespread commercialization of OLED devices. In the first step of the
inventive
fabrication method, a mixture of randomly dispersed OLED particulate in a
fluid
conductive carrier is disposed between a grid of x and y electrodes. The
electrodes are pre-patterned on a top and bottom substrate (shown, for
example, in
Figures 13, 107 and 108). The substrates are a flexible polymer. Because of
the
barrier qualities of the carrier, elaborate encapsulation layers are not
required.
Figure 34 shows OLED microcapsule chains aligned within an applied aligning
field formed within unhardened carrier fluid 12. Upon application of an
aligning
field, the OLED field-reactive material orient along the field lines and form
chains
within the still-fluid carrier 12 (analogous to electro rheological fluid
mechanics).
The next step is to apply an aligning field selectively to the volume between
the x-
and y-electrodes. The randomly dispersed particulate orient and migrate under
the
influence of the aligning field to form pixels of aligned OLED particulate.
PreferOrably, the spaces between the pixels are devoid of any particulate. The
composition of the carrier and the particulate are selected so that the
preferred
path of electrical conductivity is through the aligned particulate. This
structure
makes most efficient use of the OLED material and eliminates cross talk
between
the display pixels.
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Figure 35 shows OLED microcapsule chains aligned within an applied aligning
field held in alignment within hardened carrier 12. With the aligning field
still
applied, the carrier 12 is cured (for example, using light or heat) to form a
solid
phase to lock the chains of OLED field-reactive material into position. With
the
proper selection of carrier 12 material, the OLEDs can be energized to create
the
curing light to simplify the fabrication process. Alternatively, a light
source 28
such as a laser or other light emitter, can be used to controllably apply the
curing
light. The aligning field maintains the position of the particulate while the
carrier
is cured. The carrier changes from a fluid monomer to a hardened cross-linked
polymer by applying ultraviolet light. The formation and preservation of ultra-
thin layers of organic material is not necessary. The gap between the x- and y-
electrodes is much wider, so many of the problems of the current state-of the-
art
OLED fabrication methods are avoided. The resulting display structure is
flexible, solid-state and highly robust.
Figure 36 shows the OLED microcapsule 10 structure shown in Figure 35 with a
drive voltage applied and light being emitted from the OLED microcapsule
chains. When a voltage is applied to the electrodes 14, the OLED chain enables
hole and electron movement, raising the energy state of the OLED material and
generating light. The completed display consists of point sources of light
emission
(aligned particulate) in a solid-state protective matrix (hardened carrier).
The
resulting device structure is impervious to water and oxygen. The much wider
gap
between the electrodes greatly reduces the problem of dust and particle
contamination. If a short between the electrodes does occur, the structure is
self-
healing by automatically disconnecting the short without losing a pixel.
During
fabrication, pixel electrode alignment occurs automatically and precisely.
Extremely high resolution, full color, large-sized video displays are
obtainable.
Cross talk between pixels is eliminated, and there is no need fox any
elaborate
device encapsulation. The inventive fabrication process is readily adaptable
to
roll-to-roll processing on flexible plastic substrates using the adaptation of
well-
established polymer film fabrication methods.
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Figure 37 illustrates a method for forming an OLED particulate having a hole
transport layer and an electron transport layer. Hole transport material and
electron transport material are combined to form stable particles. Figure 37
illustrates the formation of an OLED particle. Hole transport material having
a
net positive charge and electron transport material having a net negative
charge
are mixed together in a liquid so that the opposing polarities of the
particles
creates an attractive force resulting in electrically stable particles. The
OLED
particulate is fomned by providing a first particle, comprised of a hole
transport
material that has a net positive electrical charge. A second particle is
provided
comprised of an electron transport material having a net negative electrical
charge. The hole transport particle and the electron transport particle are
brought
together in a liquid and combined to form a unified OLED particulate having a
hole transport layer and an electron transport layer forming a heterojunction
between them.
Figure 38 illustrates a method for forming an encapsulated OLED particulate.
The hole transport material and the electron transport material can be
combined
into a single particle by ejecting the constituent particles towards each
other. The
positive and negative charges will attract to form an electrically neutral
bipolar
particle. This particle may be coated with an encapsulating shell or left
uncoated.
Figures 39 - 41 show the steps for forming a multi-layered OLED particle. In
this
case, as shown in Figure 39, individual particles of electron transport
material are
imparted with a net negative electrical charge by a charge source 34 and
ejected
from a nozzle 36. Particles of a blocking material are imparted with a net
positive
charge and ejected from a second nozzle 36 towards the stream of electron
transport material particles. Field applying electrodes 38 may be provided for
directing the respective charged particles so that they combine together to
form an
electrically neutral dual layer particle. The field applying electrodes 38 may
also
be useful for attracting and removing from the combined particle stream the
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charged particles that do not combine in the dual layer particle. In a similar
manner, a dual layer hole transport and photo active layer particles can be
ejected
with induced charges and directed to combine into a dual layer particle
containing
the hole transport material and the photo active material. As shown in Figure
41,
the two dual layer particles are imparted with opposite electrical charge and
ejected from nozzle 36 towards each other where they combine to form the
completed mufti layered OLED particulate. The amount of charge induced in the
particles can be controlled to adjust the alignment of attracted constituents.
The
number of layers and their order can also be controlled as needed.
The OLED particulate comprises layered organic particles, which include a hole
transport layer and an electron emitter layer. A heterojunction is formed at
the
interface between the hole transport layer and the electron emitter layer.
Each
layered organic particle may also include a blocking layer adjacent to the
electron
emitter layer and an emissive layer adjacent to the hole transport layer,
thereby
forming a stacked organic layered structure. The blocking layer is provided
for
facilitating the proper flow of electrons and hole, and the emissive layer is
provided for facilitating the emission of photons when the energy state of the
OLED particulate is raised.
Figure 40 illustrates a second step in forming a mufti-layered OLED
particulate.
The amount of charge induced in particles can be controlled to adjust
alignment of
attracted constituents. Figure 41 illustrates a third step in forming a mufti-
layered
OLED particulate. Relatively weak attractive field keeps layered particles
properly aligned, without causing attachment of particles to electrodes 14.
The
relatively more negatively attractive ETL side attracted to a positive
attractive
force. More positive towards one end, with an overall net positive charge on
HTL/EML layered particle and more negative towards another end, with an
overall net negative charge on ETLBL layered particle. With the proper
selection
of constituent materials, the electrical properties of the HTL and ETL
material
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should be effective to cause the larger degree of induced charge to occur at
the
ends of the layered particles.
The OLED particulate may comprise a bipolar OLED microcapsule. The OLED
particulate is formed by the steps of first providing a first particle
comprised of a
hole transport material. The hole transport material has a net first
electrical
charge. A second particle comprised of an electron transport material is
provided
having a net second electrical charge. The first electrical charge is of
opposite
polarity from the second electrical charge. The first particle and the second
particle are brought together to form a unified OLED particulate having a hole
transport layer and an electron transport layer forming a heterojunction
between
them. The first particle may further include a photon-active layer. This
photon-
active layer may be a light emissive layer in which case the OLED forms a
light
emitting device, or a light receptive layer, in which case the OLED forms a
light-
detecting device.
Figure 42 schematically shows a full-color OLED display, constructed in
accordance with the present invention, having a dichromatic display layer for
improving the display contrast, power efficiency and for providing display
viewing in bright sunlight. The dichromatic display layer may be formed, for
example, using a conventional LCD pixilated light modulator layer. Further,
the
dichromatic display layer can be comprised of dichromatic microcapsules that
can
be oriented to reflect or absorb impinging light using an aligning field. The
microcapsules 40 can be electrophoretic and oriented using an applied
electrical
field. In this case, the electrophoretic microcapsules 40 are electrically
reactive.
Alternatively, in accordance with the present invention, the dichromatic
microcapsules may be magnetically reactive. In this case, the microcapsule can
be constructed having a north magnetic pole and a south magnetic pole, each
pole
being associated with a respective color of a bi-color microcapsule (e.g.,
reflective/absorbtive). A construction similar to the capacitor/OLED
microcapsule shown in Figures 2$ - 32 can be used to create microcapsules that
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can be controllably oriented in an applied magnetic field. The dichromatic
display layer provides a light reflective display for use in bright sunlight
and other
appropriate ambient light conditions, as well as other display enhancing
effects.
The dichromatic pixel layer can be formed adjacent to the last subsequent OLED
pixel layer. This dichromatic pixel layer results in a display that can be
viewed in
direct bright sunlight as well as with improved contrast in indoor ambient
lighting
conditions. Further, additional subsequent OLED pixel layers can be provided
which emit light in additional color range having a color and/or light
intensity
different from the color and/or light intensity of the other OLED pixel
layers.
To control the reflection of the emitted light from the OLED RGB pixels in
automatic mode the OLED brightness and the reflection/absorption dichromatic
microcapsule 40 is automatically controlled to optimize power consumption and
display quality. Photodetection elements are used to determine the level of
ambient light and adjust the reflection/absorption/image displaying
capabilities of
the inventive display. Further, the inventive OLED device can be configured so
as to detect light impinging on a pixel grid formed in accordance with the
present
invention. In this case, the OLED particulate of a first OLED pixel layer
emits
electrical energy in response to the reception of photons and applies the
electrical
energy as a detectable signal to the first and second layer electrodes 14.
Further, a
black and white and/or full color CCD-type camera can be formed, by tuning the
wavelength range at which subsequent layers of OLED pixels are photo reactive.
Photodetectors are used to determine when to use dichromatic display elements.
If the dichromatic pixels (e.g., dichromatic microcapsules 40) are turned to
the
reflection side, OLED emission will be reflected and more light emitted from
the
display. If turned to the absorption side, better display contrast may be
obtained.
If the OLED layers are turned off, the dichromatic pixels become a reflective
(or
two color) display for use in bright light or energy saving conditions. This
driving
scheme requires very low power - only have to apply power to the pixels to
change orientation, then the state remains until power is applied again. For
applications such as cell phones, the ability to see a display in bright light
is an
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important consideration. When the phone is in bright sunlight, the dichromatic
display elements are used and the OLEDs are off and transparent (the display
is
reflective and can monochrome (e.g., a black and white display) or full
color).
When the phone is indoors or in lower ambient light, the emissive pixels are
used
(full color display). As examples of how the dichromatic display layer
improves
the inventive display, under normal ambient light (indoor, office lighting)
the
dichromatic microcapsules 40 can be oriented to absorb the reflection of
ambient
light to improve the contrast of the display.
In low ambient light (airplane, car, dusk) the dichromatic display elements
can be
turned oriented to reflect the OLED emission so that the OLED display elements
can be driven with lower energy consumption. The dichromatic display elements
can be automatically oriented and controlled to provide power savings and
improve contrast. Light filters and side/side pixels can be mixed with the
display
stack to create a variety of display options. Further, IR and other emitters
and
detectors can also be included to create "invisible" maps that can only be
read
with night vision aides. Other display possibilities include windshields that
automatically block out high light sources like the sun and oncoming high
beams;
and goggles that enhance vision, provide night vision, and include telescopic
and
stereoscopic capabilities.
Figure 43 schematically shows the full-color OLED display shown in Figure 42,
with the dichromatic pixels oriented for reflecting emitted OLED light. When
the
dichromatic picture elements are reflective (oriented so that the reflective
side of
the sphere is facing toward the emissive side of the display), then the light
emitted
from the OLED elements is reflected for use in forming the display image. The
orientation of the dichromatic picture elements can be automatically
controlled
depending on the ambient light detected by a photodetector.
Figure 44 schematically shows the full-color OLED display shown in Figure 42,
showing the relative strength of reflected light depending on the dichromatic
pixel
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orientations. The orientation of each respective pixel stack's dichromatic
pixel
element, determines the contrast, ambient and emitted light reflectivity.
Figure 45 shows magnetically-active OLED microcapsules 10 randomly dispersed
within a fluid but hardenable carrier fluid 12 along with desiccant
particulate. The
carrier fluid 12 can include a conductive element, carbon or powdered iron for
example. The carrier fluid 12 should be selected to have the appropriate
electrical
properties so that the path of least electrical resistance in the completed
display
device is through the OLED material, and not through the carrier 12.
Accordingly, the carrier fluid 12 may have a semi-conductive composition.
Desiccant and/or scavenger particles 42 are included within the carrier fluid
12 to
improve protection against contamination. The desiccant can be for example, a
finely powdered silica based particulate, and specific oxygen scavenger
material
can also be included to further enhance the protection of the OLAM and other
constituents. Examples of the oxygen scavenger material include
dimethylpropanolamine, diethylaminoethanol, cyclohexylamine, n-n-
diethylhydroxylamine (DEHA), 2-amino-2-methyl-1-propanol, other amines, or
other suitable material composition. The specific scavenger material is
selected
depending on the other components in the device to optimize its effectiveness,
taking into consideration factors such as the device optical, electrical and
mechanical characteristics. This desiccant/scavenger can be included in the
shell
and/or the internal phase of the OLAM microcapsules, depending on the
microcapsule composition.
Figure 46 shows the magnetically-active OLED microcapsule chains aligned
within an applied magnetic aligning field within the unhardened carrier fluid
12.
The applied magnetic field can be obtained by permanent magnets brought into
position relative to the display electrodes, or electromagnets that are
controlled to
apply the magnetic field as needed to cause the desired microcapsule alignment
and orientation.
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Figure 47 shows the magnetically-active OLED microcapsule chains aligned
within the applied magnetic aligning field held in position within the
hardened
carrier 12. The carrier fluid 12 can include a conductive element - carbon,
for
example. Desiccant (water andlor oxygen scavenger) particles 42 are included
within the carrier fluid 12 to improve protection against contamination.
Figure 48 shows the magnetically-active OLED microcapsule structure with light
being emitted from the OLED microcapsule chains in response to a driving
voltage applied to the electrodes. Figure 49 schematically illustrates a full
color
OLED display having high intensity visible light display layers and an
infrared
display layer.
Figure 50 shows an OLED display layer and a liquid crystal light modulating
layer 44. The liquid crystal light modulating layer 44 can be used as the
dichromatic display layer described above. The liquid crystal light modulating
layer 44 can also provide the inventive display with the capability of being
selectively reflective. With this capability, the light-blocking windshield
described with regard to Figures 57 and 58 is obtained. Further, a window can
be
formed that is transparent when needed, can be switched to being an emissive
display (viewable from both or only one side), is selectively light blocking,
and
can be a bi-color or reflective display.
Figure 51 shows an inventive OLED display fabricated with thin films of
organic
material with photodetection elements. Photodetector elements can be
incorporated into each pixel stack, or disposed in a different resolution
grid. The
ambient light, whether sunlight, lamplight or firelight, received by the
photodetectors is used to control the optical characteristics of the OLED
pixels
associated with each photodetector. This construction can be used with
microcapsule-based fabrication or any other display constructions. This
enables
features such as windshields that block out (using, for example, LCD-type
shutters) high light sources, such as bright sunshine, overhead streetlights,
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headlights beaming from another car. OLED solar cell components or pixel
layers can be used to "recycle" the energy emitted by the OLED emitters. Some
of the emitted light energy impinges on the solar cells and generate light.
This,
along with the inventions described herein and the sheet battery described in
the
above-referenced co-owned Patent Applicant entitled "Printer and Method for
Manufacturing Electronic Circuits and Displays", can enable lightweight,
relatively inexpensive, dichromatic newspapers (as described herein in Figure
1)
that recharge in sunlight (or even indoor ambient light) to enable full-color
emissive video or still images.
Figure 52 shows an OLED microcapsule 10 wherein the shell is slightly less
conductive than the encapsulated OLED material. The shell is slightly more
resistive than the OLED material so that current does not flow around the
shell,
but instead flows through OLED material. The particulate can be organic or
inorganic, with chips of LED material combined and oriented, as necessary,
with
other materials as is described herein with regard to OLAM materials.
Figure 53 shows an OLED microcapsule 10 wherein the OLED material is
encapsulated along with an electrolyte. A hole transport material comprises
the
shell, and a shell around MAG is insulative to keep the magnetic material from
having unwanted influence of the electrical behavior of microcapsule. OLED
material is contained within the electrolyte solution, the electron carriers
in the
electrolyte can be controlled depending on the needed specification of the
microcapsules 10. For example, the microcapsules 10 charge- carrying
requirements of the electrolyte can be tailored to match the electrical flow
for a
particular OLED constituent material. Thus, microcapsules 10 can be formulated
based on the empirically or otherwise determined characteristics of a
particular
formula, or even a particular batch, of OLAM. Other additional material can be
included in the internal phase or the shell of the microcapsule, or added to
the
carrier material, or included as other microcapsules 10 within the carrier 12.
For
example, a phosphorescent OLED microcapsule 10 may require different light-
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inducing applied electrical energy. Light of a particular wavelength, for
example
infrared, can trigger the OLED emission at other wavelengths. In this case,
OLAM, or other material such an inorganic semiconductor, is included to
generate electricity in response to IR light. The generated electricity is
used to
cause an emission of other wavelengths of light by the OLED pixel layers.
Alternatively, the other wavelengths of light can be generated by particles
having
florescent or phosphorescent phenomenon. This capability makes possible a map,
for example, that can be read with an infrared flashlight (keeping the stealth
advantage, while avoiding the need for the map reader to have night vision, as
is
the case when the map is the IR emitt.
Figure 54 shows an OLED microcapsule 10 wherein the OLED material and the
hole transport material are contained in solution within a conductive shell.
This
construction may be driven with AC or DC current. The OLED particulate is
formed by microencapsulating an internal phase within a shell. The internal
phase
or the shell includes an OLED material and either the internal phase or the
shell
includes a field reactive material. The field reactive material comprises
either or
both an electrostatic and a magnetically reactive material. In accordance with
another composition of the inventive microcapsule, the internal phase
comprises
an OLED emitter material and an OLED hole transport material dispersed in
solution. Color dyes rnay also be included within the internal phase. The
solvent
may be a fluid organic solvent. In order to provide the alignment capabilities
of
the microcapsules 10, either the internal phase or the shell may include a
field
reactive component.
Figure 55 shows the OLED microcapsules 10 shown in Figure 54 including a
magnetically active material. The magnetic material is included as a separate
microcapsule 10 with an electrically insulative shell contained within the
internal
phase of a second conductive shell that also encapsulates a solution of the
OLED
material (electron transport material and hole transport material). The
electrically
insulated magnetic material enables microcapsule alignment within a magnetic
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field, without it becoming an electrical short within the microcapsule. The
OLED
microcapsules 10 can have constituent parts including at least one of hole
transport material, electron transport material, field reactive material,
solvent
material, color material, shell forming material, barrier material, desiccant
material, scavenger material, colorant material, light curable, heat
expandable,
heat contracting, heat curable and heat meltable material. The constituent
parts
of the microcapsule 10 form at least one internal phase and at least one
shell. The
constituent parts are selected so as to have electrical characteristics that
result in a
preferred path of electrical conduction (or electron and hole mobility)
through the
hole transport material and the electron transport material. By this
construction,
the microcapsule 10 behaves as a pn junction upon application of an electrical
potential to the first electrode 14 and the second electrode 14.
Figure 56 illustrates the OLED microcapsule 10 shown in Figure 54 used for
creating a general lighting or display back lighting OLED device. For general
lighting purposes, OLED and hole transport material can be microencapsulated
in
solvent form. The microcapsules 10 are randomly dispersed within a conductive
carrier 12 material, for example a conductive epoxy mixture. The microcapsules
10 can be disposed between two planer electrodes 14. The "self-healing"
capabilities described herein are used to correct electrical shorts between
the
planar electrodes 14.
Figure 57 illustrates a transparent, flexible OLED display fabricated for use
as
part of a vehicle windshield. A liquid crystal (or other) light- modulating
grid
may also be included. The light- modulating grid is used to provide a shutter
for
blocking a high intensity light source 28, such as the sun or oncoming
headlights.
Photodetector elements (which may be included in grid form within the
windshield and/or in another arrangement such as an array) detects when a
light
source 28 is at a higher intensity than the ambient light. At the location of
the
detected high intensity light source 28, the light is shuttered (e.g., liquid
crystal
within certain pixels is oriented so that the incoming light is blocked). A
radar
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system, IR camera of other object detecting system can be used to determine
when
an object is in the road, such as a deer, pedestrian, or a dog. If such an
object is
detected, its image of that object or some indication is produced in the OLED
display at the location on the windshield corresponding to where the object
would
be viewed by the driver. Information, such as speed, radio channel, incoming
cellphone call number, etc., can be displayed by the OLED display as a heads
up
display image. For an example of a driver circuit for the light shutter, a
photoactive grid generates an electrical potential between two electrodes 14.
That
electrical potential (amplified if necessary) is effective to cause structures
(molecules or crystals or molecular chains) to orient so that light is
selectively
blocked. This mechanism may also be used to create a fresnel-type lens system
(creating a curvature (focus ability) of a received light image using an
essentially
flat optical element.
Figure 58 is a block diagram showing the basic components of a driver display
system using an OLED display. A controller controls a display grid and
receives
input from a photodetector grid. A display driver drives the display grid,
under
the control of the controller, in response to the photodetector grid, an IR
camera
and/or other detection system such as a radar, sonar, ultrasonic, or the like.
Figure 59 illustrates an OLED light emissive element. The OLED element can be
constructed from sheets of OLED organic material stacks 46, and can be formed
on glass or plastic substrates 24 and cut to size. The electrode leads can be
fixed
to the cut OLED stack 46 and disposed within an evacuated or inert gas filled
bulb. The bulb can be solid and transparent or light diffusive, forming a
robust,
solid state, light bulb for flashlights or other applications where a
conventional
LED may otherwise be employed.
Figure 60 shows the OLED light emissive element having a conventional light
bulb form factor. OLED light can be fabricated into the same form factor as a
conventional light bulb so that it can be easily installed into existing light
sockets.
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The orientation of the organic stack 46, reflective electrode and transparent
electrode enables the light to be projected outward fiom the bulb. An array of
devices can be configured so that the light is emitted in an omni-directional
or
directional manner. The OLED element can be constructed from sheets of OLED
light stacks 46, and can be formed on glass or plastic substrates 24 and cut
to size.
The electrode leads can be fixed to the cut light stack and disposed within an
evacuated or inert gas filled bulb. The threaded portion of the bulb can
include an
ac to do converting circuit so that the conventional sockets, lampshades,
etc.,
already in the home or office are still usable. Alternatively, another form
factor,
such as holiday lighting, rope lighting, etc., can be used. The cut OLED light
stack can be shaped as desired, square, long and thin, etc. Also, the same
basic
structure can be used to make OLED light in a conventional LED package.
Figure 61 illustrates an OLED device fabricated using light emissive layers
and
light detecting layers. The OLED display device can include layers of light
emission pixels and layers of light detection pixels. The light detection
pixels can
be used to detect ambient light and control the intensity of the light
emission
pixels. As with some of the other device constmctions described herein, the
formation of the OLED pixel layers can be done using the inventive
microcapsule
fabrication method and/or a combination with other fabrication methods such as
inkjet, spin coating, vacuum deposition, evaporation, etc. for forming an OLED
organic stack 46.
Figure 62 illustrates stereoscopic goggles having OLED display device elements
48. The photodetection pixels can be formed so as to effect a camera
incorporated
within the OLED display device elements 48. The camera optics can include
lenses that change shape andlor focal point depending on whether the image is
focusing on the human eye or the camera pixel elements. Alternatively, or in
addition, CCD-type cameras 50 can be provided adjacent to the OLED display
device elements 48.
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Figure 63 illustrates a flexible OLED display having a curvature that
compensates
for the human eye's range of motion. The image displayed on the curved
wraparound OLED display is refreshed so that the eye movement as well as the
head movement of the user is accounted for. With this stereoscopic vision
aide,
the user's head movement can be determined by accelerometers and gyroscopic
circuits. The eye movement is determined by reflecting IR (or some wavelength
depending on the ambient light) off the retina and detecting the reflection by
photodetectors which may be incorporated in or adjacent to the OLED display
Figure 64 illustrates a flexible OLED display having microlens elements 52 for
focusing emitted light at the appropriate physical location within a human
eye.
An optical lens can be used to focus light onto CCD-type elements to create
microlens elements 52 that focus the pixel light source 54 at the focus spot
in the
human eye. The optical properties of the microlens element 52 can compensate
for vision problems
Figure 65 illustrates a wraparound visor 56 having a curved, flexible OLED
display and speakers 58. The inventive stereoscopic vision aid has a high
resolution OLED display. The OLED display is shaped so that field of vision is
as full as practical.
Figure 66(a) illustrates a wall 60 of a house having an inventive OLED display
window 62, the window 62 being driven so as to be transparent with trees 64
outside the house visible through the window 62. The inventive window 62 can
be
constructed along the lines of the OLED displays described herein. As with all
of
the applications for the inventive OLED technology, the various elements
comprising the various versions of the invention described herein can be mixed
and matched depending on the intended use fox a particular OLED display or
device. Thus, in this case, the inventive window 62 can be driven so that it
is
transparent when needed, can be switched to being an emissive display
(viewable
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from both or only one side), is selectively light blocking, and can be a full
color,
multi-color, monochrome or reflective display.
Figure 66(b) illustrates the wall 60 of a house having the inventive OLED
display
window 62, the window 62 being driven so as to display multiple simultaneous
video streams 66 including videophone communication, Internet web page and a
television program. Multiple streams of display information 66 can be
simultaneously received and displayed. For example, broadcast video content
such as a television program may be shown at a first portion of the display,
personalized video content, such as a videophone conversation may be shown at
a
second portion and a web page, including mapped hyperlink content, may be
shown at a third portion. With an LCD light modulating layer, the content
displayed on the inventive OLED display window 62 can
be viewable from outside the house (from poolside, for example), or LCD light
modulating layer can be controlled so that the emitted display light can be
blocked
from view from outside the house.
Figure 66(c) illustrates the wall 60 of a house having the inventive OLED
display
window 62, the window being driven so as to be a mirror. In this case, the LCD
light modulating layer can be controlled to block light from being transmitted
through the window. Further, as shown in Figure 57, relatively high intensity
light (such as from sun beaming onto the window) can be selectively blocked to
prevent glare within the house and to keep the house cooler in the summer.
Figure 67(a) illustrates the use of an inventive flexible large format display
as part
of a camouflage system for a vehicle, such as a military tank. In accordance
with
this aspect of the present invention, a camouflage system is provided that
includes
a video camera system that captures a field of view in a direction away from
the
object to be camouflaged, such as a military tank. On the opposite side of the
tank
relative to the field of view, a flexible large format display is used to
display to an
external viewer the captured image of the field of view. Figure 67(b)
illustrates
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the camouflage system shown in Figure 67(a) wherein the display area has a
curved viewing area. As shown in Figure 67(b), the effect of displaying the
captured field of view on the flexible display is to create the illusion for
the
external viewer that enables the military tank to effectively disappear into
the
background scene.
Figure 67(c) illustrates the use of an inventive flexible clothing display as
part of a
camouflage system for a person. As described above, a camera system captures a
field of view. This captured image is displayed on the clothing of the wearer
so
that an illusion is created that the wearer disappears into the background
scene.
Figure 67(d) shows the inventive clothing camouflage system shown in Figure
67(b) in use. The clothing may be fabricated in the manner described herein.
Figure 68(a) shows the use of flexible, lightweight solar panels as a sunlight-
to-
energy system for powering an aircraft, such as a military observation drone.
Figure 68(b) is a block diagram illustrating some system elements of the
military
observation drone shown in Figure 68(a). The flexible, lightweight solar
panels
fabricated in accordance with the present invention enable an aircraft, such
as an
observation drone, to continuously fly while being propelled, for example, by
a
propeller driven by an electric motor. The electric motor and other onboard
electrical systems receive power directly from the solar panels, or from a
battery
that is recharged by the solar panels.
Figure 69 illustrates an embodiment of the inventive light active device
showing a
semiconductor particulate randomly dispersed within a conductive carrier. A
light
active device includes a semiconductor particulate dispersed within a carrier
material. The carrier material may be conductive, insulative or semiconductive
and allows charges to move through it to the semiconductor particulate. The
charges of opposite polarity moving into the semiconductive material combine
to
form charge carrier pairs. The charge carrier pairs decay with the emission of
photons, so that light radiation is emitted from the semiconductor material.
Alternatively, the semiconductor material and other components of the
inventive
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light active device may be selected so that light received in the
semiconductor
particulate generates a flow of electrons. In this case, the light active
device acts
as a light sensor.
A first contact layer or first electrode is provided so that on application of
an
electric field charge carriers having a polarity are injected into the
semiconductor
particulate through the conductive carrier material. A second contact layer or
second electrode is provided so that on application of the electric field to
the
second contact layer charge carriers having an opposite polarity are injected
into
the semiconductor particulate through the conductive carrier material. To form
a
display device, the first contact layer and the second contact layer can be
arranged
to form an array of pixel electrodes. Each pixel includes a portion of the
semiconductor particulate dispersed within the conductive carrier material.
Each
pixel is selectively addressable by applying a driving voltage to the
appropriate
first contact electrode and the second contact electrode.
The semiconductor particulate comprises at least one of an organic and an
inorganic semiconductor. The semiconductor particulate can be, for example, a
doped inorganic particle, such as the emissive component of a conventional
LED.
The semiconductor particulate can be, for another example, an organic light
emitting diode particle. The semiconductor particulate may also comprise a
combination of organic and inorganic materials to impart characteristics such
as
voltage control emission, aligning field attractiveness, emission color,
emission
efficiency, and the like.
The electrodes can be made from any suitable conductive material including
electrode materials that may be metals, degenerate semiconductors, and
conducting polymers. Examples of such materials include a wide variety of
conducting materials including, but not limited to, indium-tin-oxide ("ITO"),
metals such as gold, aluminum, calcium, silver, copper, indium and magnesium,
alloys such as magnesium-silver, conducting fibers such as carbon fibers, and
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highly-conducting organic polymers such as highly-conducting doped
polyaniline,
highly-conducting doped polypyrrole, or polyaniline salt (such as PAN-CSA) or
other pyridyl nitrogen-containing polymer, such as polypyridylvinylene. Other
examples may include materials that would allow the devices to be constructed
as
hybrid devices through the use of semiconductive materials, such as n-doped
silicon, n-doped polyacetylene or n-doped polyparaphenylene.
In accordance with another aspect of the present invention, a photon receptive
light active device is provided. A first electrode and a second electrode are
provided disposed adjacent defining a gap there between. A light active
mixture
is provided comprised of a carrier material and a photon receptive particulate
for
receiving a photon of light and converting the photon of light into electrical
energy. The light active mixture being disposed within the gap between the
first
electrode and the second electrode so that when light energy is received by
the
photon receptive particulate, electrical energy is produced that can be
derived
from an electrical connection with the first electrode and the second
electrode.
With this composition and construction, a light-to-energy device is obtained
from
which a solar cell, photodetector or camera element can be made.
The photon receptive particulate may include at least one of an organic photon
receiver; an inorganic photon receiver, hole transport material, Mocker
material,
electron transport material, and performance enhancing materials. The carrier
can
include at least one of an organic photon receiver; an inorganic photon
receiver,
hole transport material, blocker material, electron transport material, and
performance enhancing materials. Further, additional layers may be formed
within the gap between the first electrode and the second electrode. These
additional layers help to define the mechanical, electrical and optical
characteristics of the inventive device. The additional layers may include at
least
one of an organic photon receiver, an inorganic photon receiver, hole
transport
material, blocker material, electron transport material, and performance
enhancing
materials (e.g., the characteristic controlling additives).
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As shown in Figure 70, an embodiment of the inventive light active device may
have the semiconductor particulate aligned between electrodes. The emissive
particulate acts as point light sources within the carrier material when holes
and
electrons are injected and recombine forming excitons. The excitons decay with
the emission of radiation, such as light energy. In accordance with the
present
invention, the emissive particulate can be automatically aligned so that a
significant majority of the point light sources are properly oriented and
disposed
between the electrodes (or array of electrodes in a display). This maximizes
the
light output from the device, greatly reduces cross-talk between pixels, and
creates a protected emissive structure within the water, oxygen and
contamination
boundary provided by the cured carrier material.
In this case, the mixture disposed within the gap between the top and bottom
electrodes includes a field reactive OLED particulate that is randomly
dispersed
within a fluid carrier. An aligning field is applied between the top electrode
and
the bottom electrode. The field reactive OLED particulate move within the
carrier
material under the influence of the aligning field. Depending on the
particulate
composition, carrier material and aligning field, the OLED particulates form
chains between the electrodes (similar to the particulate in an electrical or
magnetic rheological fluid in an electric or magnetic field), or otherwise
becomes
oriented in the aligning field. The aligning field is applied to form a
desired
orientation of the field reactive OLED particulate within the fluid carrier.
The
fluid carrier comprises a hardenable material. It can be organic or inorganic.
While the desired orientation of the field reactive OLED particulate is
maintained
by the aligning field, the carrier is cured to form a hardened support
structure
within which is locked in position the aligned OLED particulate.
Figure 71 illustrates an embodiment of the inventive light active device
showing
semiconductor particulate and other performance enhancing particulate randomly
dispersed within the conductive carrier material. The semiconductor
particulate
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may comprise an organic light active particulate that includes at least one
conjugated polymer. The conjugated polymers having a sufficiently low
concentration of extrinsic charge carriers. An electric field applied between
the
first and second contact layers causes holes and electrons to be injected into
the
semiconductor particulate through the conductive carrier material. For
example,
the second contact layer becomes positive relative to the first contact layer
and
charge carriers of opposite polarity are injected into the semiconductor
particulate.
The opposite polarity charge carriers combine to form in the conjugated
polymer
charge carrier pairs or excitons, which emit radiation in the form of light
energy.
Depending on the desired mechanical, chemical, electrical and optical
charactistics of the light active device, the conductive carrier material can
be a
binder material with one or more characteristic controlling additives. For
example, the binder material may be a cross-linkable monomer, or an epoxy, or
other material into which the semiconductor particulate can be dispersed. The
characteristic controlling additives may be in a particulate andlor a fluid
state
within the binder. The characteristic controlling additives may include, for
example, a desiccant, a scavenger, a conductive phase, a semiconductive phase,
an
insulative phase, a mechanical strength enhancing phase, an adhesive enhancing
phase, a hole injecting material, an electron injecting material, a low work
metal,
a blocking material, and an emission enhancing material. A particulate, such
an
TTO particulate, or a conductive metal, semiconductor, doped inorganic, doped
organic, conjugated polymer, or the like can be added to control the
conductivity
and other electrical, mechanical and optical characteristics. Color absorbing
dyes
can be included to control the output color from the device. Florescent and
phosphorescent components can be incorporated. Reflective material or
diffusive
material can be included to enhance the absorption of received light (in the
case,
for example, of a display or photodetector) or enhance the emitted light
qualities.
In the case of a solar collector, the random dispersal orientation of the
particulate
may be preferred because it will enable a solar cell to have light receiving
particulate that are randomly oriented and the cell can receive light from the
sun
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efficiently as it passes aver head. The orientation of the particulate may
also be
controlled in a solar cell to provide a bias for preferred direction of
capture light.
The characteristic controlling additives may also include materials that act
as heat
sinks to improve the thermal stability of the OLED materials. The low work
metal additives can be used so that more efficient materials can be used as
the
electrodes. The characteristic controlling additives can also be used to
improve
the mobility of the carriers in the organic materials and help improve the
light
efficiency of the light- emitting device.
Figure 72 illustrates an embodiment of the inventive light active device
showing
different species of organic light active particulate dispersed within a
carrier
material. The turn-on voltage for each species can be different in polarity
and/or
magnitude. Emissions of different wavelengths or colors can be obtained from a
single layer of the mixture of the organic light active particulate and
carrier
material. The color, duration and intensity of the emission is thus dependent
on
the controlled application of an electric field to the electrodes. This
structure has
significant advantages over other full color or multicolor light devices, and
can
also be configured as a wide spectrum photodetector for applications such as
cameras. The organic light active particulate can include organic and
inorganic
particle constituents including at least one of hole transport material,
organic
emitters, electron transport material, magnetic and electrostatic material,
insulators, semiconductors, conductors, and the like. As is described herein,
a
mufti-layered organic light active particulate can be formed so that its
optical,
chemical, mechanical and electrical properties are controlled by the various
particle constituents.
Figure 73 illustrates an organic light active particle formed from a polymer
blend
and Figure 74 illustrates the polymer blend organic light active particulate
dispersed within a conductive carrier. The organic light active particulate
may
include particles comprised from a polymer blend, including at least one
organic
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emitter blended with at least one of a hole transport material, an electron
transport
material and a blocking material. The polymer blend may be comprised of
emitters that respond to different turn-on voltages to effect a multicolor
device.
The polymer blend particulate can be dispersed within a carrier that includes
at
least one of the hole transport, electron transport, hole Mocker, or other
OLED
constituent. The carrier may also include other performance enhancing
materials,
such as lithium, calcium, low work metals, charge injection facilitators,
light-to-
light emitters (similar to the coating on a florescent light tube) to obtain
the
desired light emission. As described elsewhere herein, other particulate and
carrier additives can be incorporated to enhance the characteristics of the
OLED
device. Figure 75 illustrates the polymer blend organic light active particle
showing light active sites. Upon the application of electrical field to the
electrodes, sites within the polymer blend particle will act as point sources
of light
emissions. These light active sights are located where the appropriate
constituents
of the polymer blend meet so that electrons and holes injected into the
semiconductor material combine into excitons and decay with the release of
photons. The organic light active particulate may include microcapsules having
a
polymer shell encapsulating an internal phase. The internal phase and/or the
shell
can be comprised of the polymer blend including an organic emitter blended
with
at least one of a hole transport material, an electron transport material and
a
blocking material. As with the other constructions of the inventive OLAM
devices and material compositions, depending on the material compositions and
the device structure, this polymer blend can be used to emit radiation of
different
wavelengths and can also be used fox light-to-energy devices, such as solar
cell
and photodetectors. These structures and compositions can also be used for bio-
sensors and other organic light active applications.
One way to make the polymer blend particulate is to precipitate out the
particles
from a solution comprised of the OLED constituents in a common solvent.
Applicant has experimentally formed a polymer blend particulate from the
constituents Poly[2-Methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene]; N,N-
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Di-(napthalen-a-yl)-N,N-diphenyl-benzidine; and 2,9-Dimethyl-4,7-diphenyl-
1,1-phenanthroline. These OLED materials were obtained from H.W., Sands
Corp, Jupiter, Florida. The three OLED constituents were first dissolved in a
common solvent, chloroform, and then a non-solvent was added to form a
precipitant of the blended polymers.
Nanoparticles are used in applications, such as drug deliver devices. Others
have
shown that very small polymer-based particles can be made by a variety of
methods. These nanoparticles vary in size, typically from 10 to 1000 nm. A
drug
can be dissolved, entrapped, encapsulated or attached to a nanoparticle
matrix.
Depending on the method of preparation, nanparticles, nanospheres or
nanocapsules can be obtianed. (see, BiodegYadable Polymeric Naraoparticles as
Drug Delivery Devices, K.S., Soppimath et al., Journal of Controlled Release,
70(2001) 1-20, incorporated by reference herein). In accordance with the
present
invention, an OLED particulate can be formed having a very small particle
size.
The small particle size offers a number of advantages. For example, the
ultimate
resolution available of a display may be dependent on the size limitation of
the
OLED particles. Thus OLED nanoparticles utilized in accordance with the
inventive fabrication methods will enable extremely high resolution display
devices. Also, the very small OLED particle size will enable more light point
sources within a given volume, such as the volume making up a display pixel. A
large number of light point sources can result in more uniform pixel
characteristics, longer device lifetimes and more efficient power consumption.
In
accordance with the present invention, various methods can be employed to form
the OLED nanoparticles. The various methods disclosed in this reference for
the
formation of drug delivery nanoparticles can be adapted for the formation of
OLED nanoparticles. These methods include the solvent evaporation method,
spontaneous emulsification, solvent diffusion method, salting
out/emulsification-
diffusion method, production of OLED nanoparticles using supercritical fluid
technology, the polymerization of monomers, and nanoparticles prepared from
hydrophilic polymers.
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Figure 76 illustrates a polymer blend organic light active particulate having
a field
attractive constituent for aligning the particle in an aligning field. In this
case, the
particulate includes a field reactive material, such as a magnetically
reactive
speck. The magnetically reactive speck can be included in the particulate
through
an appropriate encapsulation, mixing, blending or coating technique.
Figure 77 illustrates composite microcapsules containing mufti-layered organic
light active particles, each having a different light wavelength emission and
turn-
on voltage. The composite microcapsules or different species of particulate
can
be used to form a single layer voltage controlled light active device for
emitting
two or more colors of light. Instead of needing a separate set of electrodes
and a
separate layer of the semiconductor and carrier material mixture, the present
invention enables a single layered device with a single pair of electrodes to
controllably emit two or more colors of light.
Figure 78 illustrates another composite microcapsule containing mufti-layered
organic light active particles, at least one having a field attractive
constituent. The
field attractive constituent may be required to enable alignment of the
particles
between the driving electrodes. When an aligning field is applied, the field
reactive OLED particulate moves within the carrier material under the
influence
of the aligning field. The aligning field is applied to form a desired
orientation of
the field reactive OLED particulate within the fluid carrier.
Figure 79 illustrates three light emitting microcapsule species, each species
having a turn-on voltage controlled by the internal phase composition and the
encapsulating shell composition. The shell may be formed of a polymer having a
conductivity based on thickness and/or composition so that the specific turn-
on
voltage of the encapsulated conjugated polymer particulate is of a desired
magnitude. By this additional turn-on voltage control enabled by the
shelllinternal phase electrical characteristics, the photons emitted by each
species
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of conjugated polymer in response to an applied voltage can be tailored as
required. The carrier fluid can be formulated so that it is more of an
insulator
prior to curing, and has the proper degree of conductivity after curing. In
this
case, the carrier fluid can act, more or less, like the oil in an
oillparticulate
electrical Theological fluid. The high voltage required to align the
particulate
between the electrodes can be applied without too much current passing through
the particulate and burning them out. Once aligned, the electrical field can
be
reduced or eliminated as the carrier fluid cures. The carrier fluid can also
have
additives that affect the turn-on voltages of the different emitter species so
that the
appropriate number of photons is emitted from each point light source for each
applied turn-on voltage.
Figure 80 illustrates an embodiment of the inventive voltage controlled light
active device showing the composite microeapsule particulate randomly
dispersed
within a carrier. The internal phase may be a polymer blend containing two or
more conjugated polymers, each with a specific turn-on voltage for the
controlled
emission of color light. In an embodiment of a voltage controlled multi-
colored
light emitting device, a first electrode is provided with a second electrode
disposed adjacent to it and defining a gap there- between. A mixture of an
organic light active particulate and a conductive carrier material is disposed
within said gap. The organic light active particulate is comprised of first
emitting
particles including a first electroluminescent conjugated polymer. The first
emitting particles emit a number of photons of a first color in response to a
first
turn-on voltage applied to the electrodes. The first emitting particles also
emit a
different number of photons, zero or more, of the first color in response to
other
turn-on voltages. The organic light active particulate further comprises
second
emitting particles including a second conjugated polymer. The second emitting
particles emit a number of photons of a second color in response to a second
turn-
on voltage and a different number of photons of the second color in response
to
other turn-on voltages. Thus, in the case of a mufti-colored diode or display,
different colors are perceivable by the human eye depending on the applied
turn-
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on voltage. The organic light active layer may also include third emitting
particles
including a third electroluminescent conjugated polymer. The third emitting
particles emit a number of photons of a third color and/or intensity in
response to
a third turn-on voltage applied to the electrodes and a different number of
photons
of the third color and/or intensity in response to other turn-on voltages. A
full
color display can be obtained by having the first color red, the second color
green
and the third color blue.
The composite microcapsule can contain three OLED particles or microcapsules,
or it may be made from conjugated polymers and other material, such as non-
conjugated polymers, organic light active materials, field attractive
materials,
inorganic light active material, etc.. Each emitter emits light of a specific
color
range, R, G or B. Each color particle is formulated so that it emits light
when a
voltage in a specific voltage range is applied between the electrodes. A
plurality
of composite microcapsules are dispersed Within a carrier fluid. The carrier
fluid
may be a hardenable material, such as an epoxy, resin, curable organic or
inorganic material, heat or light curable monomer, and the like.
Figure 81 illustrates an embodiment of the inventive voltage controlled light
active device showing the composite microcapsule particulate aligned between
electrodes. An aligning field applied between the top electrode and the bottom
electrode causes the field reactive OLED particulate to move under the
influence
of the aligning field. Depending on the particulate composition, carrier
material
and aligning field, the OLED particulate forms chains between the electrodes
(similar to the particulate in an electrical or magnetic rheological fluid
when an
electrical or magnetic field is applied), or otherwise becomes oriented in the
aligning field. The aligning field is applied to form a desired orientation of
the
field reactive OLED particulate within the fluid carrier. The fluid carrier
may
comprise a hardenable material. While the desired orientation of the field
reactive
OLED particulate is maintained by the aligning field, the carrier is cured to
form a
hardened support structure within which is locked in position the aligned OLED
particulate.
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Figure 82 illustrates the retinal response of the human eye to wavelengths of
light
in the visible spectrum. When light enters the eye, it first passes through
the
cornea at the front of the eye and ultimately reaches the retina at the back
of the
eye. The retina is the light-sensing structure of the eye. The retina includes
two
types of cells, called rods and cones. Rods are responsible for vision in low
light,
and cones responsible for color vision and detail. There are three types of
cones,
each type responsive primarily to a specific segment of the visual spectrum.
The
light received by these rod and cone cells sets off complex chemical
reactions.
The chemical that is formed (activated rhodopsin) creates electrical impulses
in
the optic nerve. The brain interprets these electrical impulses in the visual
cortex.
The color-responsive chemicals in the cones are called cone pigments and are
very similar to the chemicals in the rods. There are three kinds of color-
sensitive
pigments, red-sensitive pigment, green-sensitive pigment and blue-sensitive
pigment
Each cone cell has one of these pigments so that it is sensitive to that
color. The
human eye can sense almost any gradation of color when red, green and blue are
mixed. Humans are able to perceive color throughout the visual spectrum
because
of the responsiveness of the three types of cones. Red absorbing cones absorb
best
at the relatively long wavelengths peaking at 565 nm. Green absorbing cones
have a peak absorption at 535 nm and blue absorbing cones have a peak
absorption at 440 nm. The three types of cones axe each most responsive to
different portions (R,G,B) of the visible spectrum, but the segment of
responsiveness overlap. Light of a given wavelength (color), for example 500
nm
(green), stimulates all three types of cones, but the green-absorbing cones
will be
stimulated most strongly.
Typically, a full color display has side by side RGB pixels and generates
three
simultaneous emissions of RGB colored light, producing a mixture of
wavelengths of light. Color is perceived by the eye through the simultaneous
stimulation of the three types of cones by the color light mixture. In
accordance
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with the present invention, a color is obtained by driving a multi-color
producing
light active device with an emission cycle during which the appropriate number
of
photons of different colors are produced in successive bursts of light
emissions. A
predominance of photons of a color is produced during a burst of emission in
response to the application of a turn-on voltage. Another burst of a
predominance
of photons of another color is produced in response to the application of a
different turn-on voltage. A fraction of the emission cycle is determined
during
which each turn-on voltage is applied so that an appropriate number of photons
for each color is produced for each burst. The eye perceives the desired color
by
the successive predominate stimulation of each type of cone cell. Color is
obtained by the combination of Xd # of photons of Red + Yd # of photons of
Green Zd # of photons of Blue. It may turn out experimentally that other
wavelengths of light can be used to stimulate the vision system to perceive
variable colors from the burst emission of photons, in which case the number
and
wavelength of the different colors along the emissive spectrum can be
employed.
The shell of each particle may be a controlling effect on the turn-on voltage
of the
encapsulated OLED. The composition of the encapsulated OLED controls the
color of the light emitted. The shell thickness and composition can be
controlled
so that the turn-on voltage of each primary color particulate is distinct from
the
turn-on voltage of the others. For example, each RGB particle can have a
specific
shell structure selected so that when a high turn-on voltage is applied, the
electrons move too slowly through the lower voltage shell and/or internal
phase to
cause complete or partial turn-on (i.e., reduced number of emitted photons) of
the
encapsulated emitter.
Each color emitter can be formulated so that it has a different threshold turn-
on
voltage and/or a different threshold turn-on pulse width and/or a different
threshold turn-on polarity. As an example, since more electrons and holes move
at higher voltage potential, the higher voltage emitter made to have a lower
pulse
width would emit the same number of photons as the lower voltage, longer pulse
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width emitters. But, even though the voltage threshold for lower voltage
emitters
is exceeded when the higher voltage emitter is driven, the pulse width of the
higher voltage is too short to turn-on the lower voltage emitter. As an
example,
the hole and/or electron transport material can be formulated to slow down the
progress of the electrons and holes in the lower voltage material so that even
though more electrons and holes are injected at the higher voltage, are not
able to
cross through the material and recombine in the lower voltage emitter (the
recombination of the holes and electrons results in a photon).
A variable DC/AC voltage/current source applies electrical energy to the
electrodes. In response to the applied energy, light is emitted from the
particulate
through the top electrode. In an AC voltage application, each cycle has a
predetermined voltage. With each cycle, a predominant color of light (for
example, R, G, B) is emitted in response to the predetermined voltage (or no
color
is emitted). The color emitted depends on the turn-on voltage of the R, G or B
particles. Dual color particles or tri color particles (or 4 colors, including
IR, for
example) are obtainable by the various known particulate construction
techniques
and those described herein. The burst emission cycles are fast enough that the
eye
perceives the desired color of the visible spectra. Fox example, rods and
cones of
the eye are stimulated by the three primary colors separately but in quick
succession so that each frame of a video, for example, is perceived in full
color.
Because of the very fast turn-on times of the emitting particles, and the
burst
emission driving scheme, a passive matrix can be used while still obtaining
superior video images. Each individual scan cycle of an electrode pair can
have a
large number of burst cycles. With each burst cycle, a particular predominant
color is emitted. Thus, in each scan cycle, the eye see separate colored light
bursts but the cones and rods are stimulated in such quick succession that a
mix of
the primaxy colors (or, if preferable other two or more colors) is perceived
by the
brain from the optic nerve.
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By selecting the appropriate formula of the conductive carrier, it can be a
hole
transport vehicle and an electron transport vehicle. The organic emitter may
not
have to be a multi-layered particulate, but rather, it may be just particles
of pure
organic emitter.
Depending on the configuration and composition of the various components, the
inventive voltage controlled light active device can be AC driven, with the
first
turn-on voltage having a polarity and the second turn-on voltage having an
opposite polarity. The different turn-on voltages can be a mix of voltages of
different polarities and magnitudes.
The organic light active layer may also comprise at least one additional
emitting
particles containing another electroluminescent conjugated polymer. The
additional emitting particles emitting a number of photons in response to a
turn-on
voltage and a different number of photons in response to other turn-on
voltages.
The photons emitted by the additional emitting particles can have a color that
is
within the visible spectrum. In this case, the additional emitting particles
can
enhance the visible display capabilities. For example, the intensity of the
light
emitted by one of the primary color emitters may become diminished because of
the emitter service lifetime. Other emitters having the same color, but
different
turn-on voltage can be put into service to maintain the effectiveness of the
total
display. The photons emitted by the emitting particles may also be outside the
range of the visible spectrum. For example, infra-red photons can be
controllably
emitted to enable stealth military application of the inventive display.
The voltage controlled organic light active device can be constructed as a
display.
In this case, the first electrode is part of an x-grid of electrodes and the
second
electrode is part of a y-grid of electrodes. The mixture of the organic light
active
particulate and the conductive carrier material in the gap between the first
electrode and the second electrode make up an emissive component of a pixel of
a
display device.
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As an example of voltage controlled emitter, the first and the second
electroluminescent conjugated polymers may include a plurality of members
selected from the group consisting of polythiophenes, poly(paraphenylenes),
and
poly(paraphenylene vinylene), at least some of said members having
substituents
selected from the group consisting of alkyl, alkoxy, cycloalkyl, cycloalkoxy,
flouroalkyl, alkylphenylene, and alkoxyphenylene vinylene.
An organic light active display device includes a substrate with a first grid
of
driving electrodes formed on the substrate. A second grid of electrodes is
disposed adjacent to the first grid of electrodes and defining a gap there-
between.
A mixture of an organic light active particulate and a conductive carrier
material
is disposed within the gap. The organic light active particulate comprising
first
particles including a first electroluminescent conjugated polymer having a
first
turn-on voltage and second particles including a second electroluminescent
conjugated polymer having a second turn-on voltage different than the first
turn-
on voltage. When the first turn-on voltage is applied, a first color is
emitted by
the first electroluminescent conjugated polymer. Light having a second color
is
emitted by the second electroluminescent conjugated polymer in response to the
second turn-on voltage applied to the first electrode and the second
electrode.
Figure 83 illustrates the inventive primary color burst driving method for
producing a perceived full color image by the rapid and sequential bursts of
primary colored light emission. Tn accordance with the present invention, a
method is provided for driving a mufti-color light emitting device, the mufti-
color
light emitting device capable of emitting two or more colors in sequence. Each
color is emitted in response to a respective different applied turn-on
voltage.
During an emission cycle, a first turn-on voltage is applied having a duration
to
the light emitting device so that a first burst of a predominant number of
photons
of a first color are emitted. A second turn-on voltage is then applied during
the
emission cycle having a duration and at least one of a magnitude and a
polarity
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different than a magnitude and polarity of the first turn-on voltage. For the
second turn-on voltage duration, a second burst of a predominant number of
photons of a second color are emitted. In this way, during the emission cycle
the
first burst and the second burst. occur in rapid succession. A human eye
receiving
the first burst and the second burst is stimulated to perceive a color that is
different than the first color and the second color.
During the emission cycle, a third turn-on voltage can be applied having a
duration and at least one of a magnitude and a polarity different than the
magnitude and polarity of the other turn-on voltages. A third burst of a
predominant number of photons of a third color are emitted. During the
emission
cycle, the first burst, the second burst and the third burst occur in rapid
succession
and the human eye receiving the bursts is stimulated to perceive a color
different
than the first color, the second color and the third color.
In accordance with the present invention, the first color is in the red
portion of the
visible spectrum, the second color is in the green portion of the visible
spectrum
and the third color is in the blue portion of the visible spectrum. The light-
emitting device is controlled so that the number of photons of each color
emitted
during each burst of the emission cycle results in a predetermined color
within the
visible spectrum being perceivable by the human eye. Even though there is not
the three simultaneous emissions of R,G,B emitted by a typical full color
display,
in accordance with the present invention, the successive burst emission
results in
the perception of a predetermined color in the visible spectrum.
Figure 84 illustrates the inventive retinex burst driving method for producing
a
perceived full color image by the rapid and sequential bursts of colored light
emission. In accordance with another aspect of the present invention, the
intensity, duration and color emitted by the multi-color light emitting device
is
adjusted according to a retinex display operation. Edwin Land introduced a
theory
of color vision based on center/surround retinex (see, An Alternative
Technique
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for the Computation of the Designator in the Retinex Theory of Color Vision,"
Proceedings of the National Academy of Science, Volume 83, pp. 3078-3080,
1986). Land disclosed his retinex theory in "Color Vision and The Natural
Image," Proceedings of the National Academy of Science, Volume 45, pp. 115-
129, 1959. These retinex concepts are models for human color perception. The
earlier retinex concepts involved the computations based on when color
boundaries were crossed in the light emitted from an image. Land's retinex
concept of human vision has a center/surround spatial computation with a
center
having 2-4 arc-minutes in diameter and a surround that is an inverse square
function with a diameter of about 200-250 times that of the center. Others
have
shown that a digital image can be improved utilizing the phenomenon of retinex
(see, U.S. Patent No. 5,991,456 issued to Rahman et al, the disclosure of
which is
incorporated by reference herein). The inventors of the 5,991,456 patent used
Land's retinex theory and devised a method of improving a digital image where
the image is initially represented by digital data indexed to represent
positions on
a display. The digital data is indicative of an intensity value Lsub.i (x,y)
for each
position (x,y) in each i-th spectral band. The intensity value for each
position in
each i-th spectral band is adjusted to generate an adjusted intensity value
for each
position in each i-th spectral band in accordance with an equation based on
the
total number of unique spectral bands. A surround function is used to improve
some aspect of the digital image, e.g., dynamic range compression, color
constancy, and lightness rendition. The adjusted intensity value for each
position
in each i-th spectral band is filtered with a common function. According to
the
inventors of the 5,991,456 patent, an improved digital image can then be
displayed based on the adjusted intensity value for each i-th spectral band so-
filtered for each position.
Figure 85 illustrates the inventive adjusted color burst driving method for
producing a perceived full color image by the rapid and sequential bursts of
adjusted colored light emission. The retinex display operation may include the
steps of providing digital data indexed to represent positions on a display.
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digital data is indicative of an intensity for each position in each spectral
band.
The intensity of each position in each spectral band is adjusted to generate
an
adjusted intensity value in accordance with a predetermined mathematical
equation. The adjusted intensity value is filtered for each position with a
common
function. The turn-on voltages are controlled so that the emission of photons
of
each color is based on the adjusted intensity value for each filtered spectral
for
each position.
Figure 86 is a flow chart showing the steps of the inventive method for
forming a
multi-layered organic light active material particulate. Figure 87 illustrates
a
layered organic light active material particulate formed by the commingling of
a
particle of hole transport material with a particle of emissive layer
material. In
this example, a first mist comprises a hole transport material (HT) and
carrier, and
a second mist comprises an emission layer material (EL) and carrier. Figure 88
illustrates the inventive method of forming a layered organic light active
material
particulate from a hole transport constituent and an emissive layer
constituent.
Referring to Figures 86-88, a first mixture ((HT) and carrier) is formed of a
first
organic light active component material and a first carrier fluid (step one).
A
second mixture ((EL) and carrier) is formed of a second organic light active
component material and a second carrier fluid (step two). A first mist or very
fine
droplets is generated of the first mixture in an environment so that a first
particulate of the first organic light active component material is
temporarily
suspended in the environment (step three). A second mist of the second mixture
is
generated in the environment so that a second particulate of the second
organic
light active component material is temporarily suspended in the environment
(step
four). The first particulate and the second particulate are allowed to
commingle
and attract together in the environment to form a first layered organic light
active
material particulate ((HT)(EL)) (step six). The layered organic light active
particulate has a first layer of the first organic light active component
material and
a second layer of the second organic light active component material.
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Figure 89 illustrates a multi-layered organic light active material
particulate
formed by the commingling of a layered particle of hole transport/ennissive
layer
material with a particle of electron transport material. Figure 90 illustrates
the
inventive method of forming a multi-layered organic light active material
particulate from a hole transport/emissive layer constituent and an electron
transport constituent. An organic light active material particulate can be
formed
having multiple layers. A third mixture is formed of a third organic light
active
component material (ET) and a third carrier fluid. A fourth mixture is formed
of
the first layered organic light active material particulate ((HT)(EL)) and a
fourth
carrier fluid. A mist of the third mixture is generated in the environment so
that a
third particulate of the third organic light active component material is
temporarily suspended. A mist of the fourth mixture is generated so that the
first
layered organic light active material particulate is temporarily suspended in
the
environment. The third particulate and the first layered organic light active
material particulate are allowed to commingle and attract together in the
environment to form a second layered organic light active material
particulate.
This second layered organic light active material particulate includes the
first
organic light active material particulate and the third organic light active
component material. Thus the resulting organic light active material
particulate
has a mufti-layered structure that includes all three of the organic light
active
component materials arranged in a desired order ((HT)(EL)(ET)).
In accordance with the present invention, a multilayered particulate structure
can
be obtained for obtaining electrophosphorescent OLED particulate. Figure 91
illustrates a layered organic light active material particulate formed by the
commingling of a particle of blocking material with a particle of electron
transport
material. Figure 92 illustrates the inventive method of forming a layered
organic
light active material particulate from a blocking constituent and an electron
transport constituent. Figure 93 illustrates a layered organic light active
material
particulate formed by the commingling of a particle of emissive layer material
with a particle of hole transport material. Figure 94 illustrates the
inventive
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method of forming a layered organic light active material particulate from an
emissive layer constituent and a hole transport constituent. Figure 95
illustrates a
mufti-layered organic light active material particulate formed by the
commingling
of a layered particle of blockinglelectron transport material with a layered
particle
of emissive layerihole transport material. Figure 96 illustrates the inventive
method of forming a mufti-layered organic light active material particulate
from a
blockinglelectron transport constituent and a hole transport/emissive layer
constituent. As shown in Figures 89-96, a mufti-layered particle can be built
up
having the constituent parts ordered in a desired manner so that the mufti-
layered
particle is an effective point source light emitter.
Additional layers can be added to the mufti-layered structure by forming
another
mixture of another organic light active component material and another carrier
fluid and forming yet another mixture of a previously formed layered organic
light
active material particulate and yet another carrier fluid. The resulting
particles are
suspended in the environment as described above and allowed to commingle and
attract together to form the mufti-layered particulate structure.
At least one of the first, second and subsequent organic active component
material
may comprise at least one of a hole transport material, an emission layer
material,
an electron transport material, and a blocking material. Other organic active
component material can include at least one of a magnetic material, an
electrostatic material, a desiccant, hole injecting material, and an electron
injecting material. Thus, a selection of constituents can be made so that a
multi-
layered particulate structure can be formed having desired electrical,
optical,
mechanical, field attractive and chemical properties. The number of layers and
their order and composition can be controlled depending on the desired
particulate
attributes.
Figure 97 illustrates a layered organic light active material particulate
formed by
the commingling of a particle of field attractive material with a particle of
electron
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transport material. Figure 98 illustrates the inventive method of forming a
layered
organic light active material particulate from a field attractive constituent
and an
electron transport constituent. Figure 99 illustrates a layered organic light
active
material particulate formed by the commingling of a particle of emissive layer
material with a particle of hole transport material. Figure 100 illustrates
the
inventive method of forming a layered organic light active material
particulate
from an emissive layer constituent and a hole transport constituent. Figure
101
illustrates a mufti-layered organic light active material particulate formed
by the
commingling of a layered particle of field attractive/electron transport
material
with a layered particle of emissive layerlhole transport material. Figure 102
illustrates the inventive method of forming a mufti-layered organic light
active
material particulate from a field attractive/electron transport constituent
and a hole
transport/emissive layer constituent. As shown in Figures 97-102, the point
source light emitting particulate can be field attractive by the inclusion of
a
material, such as a magnetically reactive material, as one of the constituents
of the
particulate.
At least one of the first and the second and subsequent carrier fluids may be
a
solvent of the organic light active component material, and the solvent
removed
by evaporation or otherwise to leave the particulate suspended in the
environment.
Alternatively, a precipitation can be obtained by a suitable chemical reaction
depending on the component material and the solvent. The chemical reaction may
be caused by the addition of material to the solution prior to or after
forming the
mist. The chemical reaction may be caused by the carrier material of the
opposing mist, or the precipitating material may be otherwise applied when the
solution is in the mist form. The environment can be gaseous, liquid or a
vacuum.
It may have a flow, such as a flow of inert gas, to carry away evaporated
solvent
andlor to more the very fine droplets and the commingled particulate.
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The first, second and subsequent organic light active component material may a
fine particulate insoluble in the respective first, second and subsequent
carrier
fluids.
The third and subsequent organic light active particulate may be a multi-
layered
organic light active material particulate, which may be formed by the
inventive
method, microencapsulation, chemical reaction of two or more constituents,
electric or magnetic attraction of two or more constituents, or other means
for
forming a multi-layered organic light active material particulate. The organic
light active material particulate formed in accordance with the inventive
method
may also be encapsulated in a shell to impart chemical, magnetic, electrical
or
optical attributes to the particulate. For example, in the case of a voltage
controlled emitter, the microcapsule shell can be composed of a material
selected
to prevent unwanted photon emission from the internal phase emitter, andlor to
promote wanted photon emission from the emitter, depending on the applied turn-
on voltage.
The environment in which the particulate is formed can be an inert gas,
reactive
gas, a vacuum, a liquid or other suitable medium. For example, it may be
advantageous for the environment to include elements that perform a catalytic
function to promote a chemical reaction in or between the constituents in the
mists. A characteristic enhancing treatment may be performed on the formed
layered organic light active material particulate. The treatment may be a
temperature treatment, a chemical treatment, a light energy treatment to
cause, for
example, light activated cross-linking, or other characteristic enhancing
treatment
to impart desired attributes to the formed particulate.
The constituents that attract and form the particulate may be given a charge
to
encourage the commingling into the particulate. For example, the first mist
may
be given a charge have a polarity and the second mist given a charge having an
opposite polarity. The electrical attraction is thus enhanced between the
first
organic light active particulate and the second organic light active
particulate.
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Figure 103 is a cross section of a coated cathode fiber having a blocking
layer
formed on the cathode fiber and an electron transport layer formed on the
blocking layer. Figure 104 is a cross section of a coated anode fiber having a
hole
transport layer formed on the anode fiber and an emissive layer formed on the
hole transport layer.
Figure 105 illustrates the coated cathode fiber and the coated anode fiber
twisted
together to form an emissive fiber. In accordance with this aspect of the
invention, a conductive fiber is coated with the organic light emitting
material. A
single conductive fiber can be coated with all or any number of the layers of
the
organic stack, including a blocking layer, electron transport layer, emissive
layer,
hole transport layer, etc. A second conductor can then be formed over the
organic
stack, such as TTO, so that light generated in the organic stack is emitted
through
the transparent ITO layer. Alternatively, a conductive wire can be coiled
around
the organic stack to act as the second conductor. As shown in Figures 35 and
36,
as another alternative, the cathode and anode fibers can be coated with
respective
layers of the organic stack and then, as shown in Figure 105, twisted together
to
form an emissive fiber.
Figure 106 shows a method for coating an electrode fiber with organic light
active
device material. The electrode fiber can be spray coated, spin coated, dip
coated
and/or plated with the appropriate layers of the organic stack. Alternatively,
the
electrode fiber can be vacuum coated, evaporation coated, etc. These emissive
fibers can be used for making items, such as lights, clothing, wall hangings
and
carpeting that emit light.
Figure 107 is a schematic view of a fabrication line utilizing the inventive
OLED
particulatelconductive carrier mixture. In accordance with the present
inveniton,
traditional polymer film fabrication techniques can be applied to the
formation of
a solid state, flexible, high resolution display. These fabrication techniques
can
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also be used to form other solid state light active devices such as lighting
components and solar panels.
An example of the inventive fabrication method in a roll-to-roll process
begins
with a supply roll of bottom substrate and a supply roll of top substrate. The
substrates have preformed on them transparent electrode patterns. A slot-die
coating stage introduces onto the bottom substrate a film of a fluid carrier
containing randomly dispersed OLED particulate. The top substrate is placed
over this film. Pressure rollers ensure the proper uniform thickness of the
particulate/carrier mixture between the substrates. At an aligning stage, an
aligning field is applied to the OLED particulate. This applied field causes
the
particulate to orient and align within the still fluid carrier. With the
applied field
maintaining the position of the aligned particulate, the carrier is hardened
at the
curing stage. The aligned particulate is locked in position between the top
and
bottom electrode grids within the now solid-state carrier. A treatment stage
can
be provided, as necessary, to perform a heat or pressure treatment, or other
process, on the completed display before it is rolled up by the take-up reel.
Our fabrication method has the advantage of utilizing existing polymer film
substrates, and mature roll-to-roll processing technology. Further, our OLED
particulate/carrier fluid composition can be used in other fabrication
processes,
including screen and lithographic printing, injection molding, and resin
casting.
Using the inventive OLED material composition and fabrication method, the
problems of OLED display encapsulation are overcome by the combination of the
barrier properties of our cured carrier, desiccant and scavenger protective
particulate (if necessary), and the well-known water/oxygen polymer film
barriers
used in other applications, like pharmaceuticals. Delicate organic thin films
are
replaced by robust OLED particulate or microcapsules that are protected within
a
solid-state matrix. Display contrast is enhanced by selecting the appropriate
optical qualities of the cured carrier, avoiding the need for costly
alternatives such
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as anti-reflection layers. The inventive fabrication method will be extremely
fast
and material efficient, and will make the manufacture of an inexpensive, thin,
lightweight, bright, flexible display a near-term practical reality.
Figure 108 shows a polymer sheet substrate having printed on it an electrode
pattern. The pre-patterned electrodes can be formed on the substrate using a
drum
printing method, screen printing, spray, offset, inkjet or other suitable
printing
technique. The electrode may be comprised of a conductive printable ink that
include, for example, a conductive polymer in solution. After printing the
electrode pattern, the solvent evaporates leaving behind the patterned
conductive
electrode. Electrochemically prepared polythieno[3,4-b]thiophene is highly
transparent and conductive. This material, or other suitable conductive
polymer,
metal, or other material can be used as the conductive pre-patterned
electrode.
One of the biggest challenges to the OLED display industry is from
contamination
by water and oxygen. The materials involved in small molecule and polymer
OLEDs are vulnerable to contamination by oxygen and water vapor, which can
trigger early failure. This issue is exacerbated when non-glass substrates are
used.
Since OLEDs offer the promise of a bendable display, attempts have been made
to
use plastic substrates in place of glass. Elaborate barrier mechanisms have
been
proposed to encapsulate the OLED device and protect the organic stack from the
ingress of water and oxygen. Also, externally applied desiccants have been
used
to reduce the contamination. Neither of these solutions is adequate, adding to
the
cost and complexity of forming an OLED device. In the end, the problems caused
by the ingress of water and oxygen to the organic stack continue to pose
serious
technical issues. Figure 111 illustrates a prior art OLED device. Very
basically,
an OLED is comprised of extremely thin layers of organic material forming an
organic stack. These layers are sandwiched between an anode electrode and a
cathode electrode. When voltage is applied to the electrodes, holes and
electrons
are injected into the organic stack. The holes and electrons combine to from
unstable excitons. When the excitons decay, light is emitted.
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The current state of every available OLED fabrication technology requires the
formation of very thin films of organic light emitting material. These thin
films
are formed by a variety of known techniques such as vacuum deposition, screen
printing, transfer printing and spin coating, or by the re-purposing of
existing
technology such as ink jet printing. In any case, the current state of the art
has at
its core the formation of very thin film layers of organic material. These
thin films
must be deposited uniformly and precisely. Such thin layers of organic
material
axe susceptible to major problems, such as oss of film integrity, particularly
when
applied to a flexible substrate. Figure 112 illustrates a prior art OLED
device
wherein a dust spec creates an electrical short between the electrodes. The
extreme thinness of the layers of organie material between conductors also
results
in electrical shorts easily forming due to even very small specks of dust ar
other
contaminants. Because of this limitation, costly cleanroom facilities must be
built
and maintained using the conventional OLED thin film fabrication techniques.
Currently, inkjet printing has gained ground as a promising fabrication method
for
making OLED displays. However, there are some serious disadvantages to the
adaptation of inkjet printing to OLED display fabrication. Inkjet printing
does not
adequately overcome the problem of material degradation by oxygen and water
vapor. Figure 113 illustrates a prior art OLED device wherein the thin organic
film stack is degraded by the ingress of oxygen and/or water. Elaborate and
expensive materials and fabrication processes are still required to provide
adequate encapsulation to protect and preserve the thin organic films. It is
difficult
to align display pixel-sized electrodes and inkjet printed OLED material with
the
accuracy needed to affect a high-resolution display.
Figure 109 illustrates the expanded gap distance between electrodes in
accordance
with the present invention. For illustrative purposes, the difference between
the
gap distance of the electrodes in a thin film organic stack is shown in prior
art
Figure 111, as compared with the much greater gap distance between the
electrodes in accordance with the present invention as shown in Figure 109. In
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fact, the gap distance difference can be much greater than even that
illustrated,
depending on the composition of the particle/carrier matrix and the applied
voltage. A thin film OLED device typically has organic stack layers that are
deposited with a thickness on the order of about 100 nm. Some layers axe less,
some are more depending on the material, the desired structure and the thin
film
forming method. However, in any case all the conventional methods for forming
thin film OLED devices result in extremely thin amounts of material disposed
between electrodes that are spaced very close apart. One of the salient points
is
that the greatly expanded gap distance between electrodes enabled by the
inventive OLED device structure translates into many advantages over the thin
film OLED device structures. Among the advantages are the reduction or
elimination of cross talk between pixels, much greater tolerance for
inclusions of
foreign particles, the additional of performance enhancing materials into the
matrix structure, as well as the many mechanical, electrical and optical
advantages
discussed elsewhere herein and other such advantages that are not enumerated.
Further, the composition of the particulate and the carrier can be tailored
depending on the desired OLED characteristics. The particulate can include a
mixture or single component of organic and inorganic emitter(s), hole
transport,
blocker, electron transport, and performance enhancing materials. Also, the
carrier can include a mixture or single component of organic and inorganic
emitter(s), hole transport, Mocker, electron transport, and performance
enhancing
materials. Additional layers can be formed between the electrodes and the
paxticulate/carrier layer. These additional layers can include a mixture or
single
component of organic and inorganic emitter(s), hole transport, blocker,
electron
transport, and performance enhancing materials.
Applicants have discovered that the ultra thin film nature of a conventional
organic light active device results in many disadvantages. These disadvantages
include, but are not limited to, electrical shorts caused by the inclusion of
small
foreign particles, cross talk among pixels in a display array, delamination of
the
thin film, deterioration of the thin film by the ingress of oxygen and water,
and
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other serious failings. In accordance with the present invention, the
disadvantages
caused by having an extremely small gap distance between electrodes is
overcome
by expanding this gap distance. Thus, in accordance with the present
invention,
an organic light active device includes a first electrode and a second
electrode
disposed adjacent to the first electrode. The first and second electrode
define a
gap there between. An organic emissive layer is disposed within said gap. To
overcome the thin film issues, and to enhance the performance of the inventive
device, a gap expanding composition is also disposed within said gap. This gap
expanding composition is effective to increase the gap distance between the
top
and bottom electrode.
The gap expanding composition may include at least one of an insulator, a
conductor and a semiconductor. The gap expanding composition can include at
least one additional layer which may be formed between the first electrode and
the
second electrode. The additional layers may include at least one of an organic
photon receiver, an inorganic photon receiver, hole transport material,
blocker
material, electron transport material, radiation emitting material and
performance
enhancing materials. The gap expanding composition can include at least one of
a
dessicant; a scavenger, a conductive material, a semiconductive material, an
insulative material, a mechanical strength enhancing material, an adhesive
enhancing material, a hole injecting material, an electron injecting material,
a low
work metal, a blocking material, and an emission enhancing material.
The emissive layer can comprise an emissive particulate dispersed within a
carrier.
The emissive particulate has a first end having an electrical polarity and a
second
end having an opposite electrical polarity. The particulate can be alignable
within
the conductive carrier so that charge carriers of a first type are more easily
injected into the first end and charge carriers of a second type are more
easily
injected into the second end.
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The emissive layer may be an organic thin film layer. The gap expanding
composition can include a conductive, insulative and/or semiconductive
material
composition that reduces the emission efficiency of the emissive layer while
increasing the light active device effectiveness by expanding the gap distance
between the electrodes. With a careful selection of constituent components,
this
reduction in efficiency can be limited so that the benefits of expanding the
gap
distance between the electrodes can be obtained without too much cost in
device
efficiency.
Figure 110 illustrates a single layered mufti-color pixel in accordance with
the
present invention. In accordance with one of the embodiments of the present
invention, a multicolor OLED device is formed that includes particulate that
is
capable of emitting photons corresponding to a visible (or invisible) spectrum
of
radiation depending on an applied voltage or other emission triggering
mechanism.
Figure 114 is a cross sectional schematic view illustrating the extrusion of
light
active fiber having aligned OLED particulate. Figure 115 is a perspective
schematic view illustrating the extrusion of light active fiber. Figure 116 is
a cross
section of a segment of extruded light active fiber. Figure 117 is a schematic
view
of the segment of extruded light active fiber driven by a voltage applied
between
electrodes. The inventive light active fiber includes an elongated hardened
conductive carrier material. A semiconductor particulate is dispersed within
the
conductive carrier material. As shown in Figure 117, a first contact area is
provided so that on application of an electric field charge carriers of a
first type
are injected into the semiconductor particulate through the conductive carrier
material. A second contact layer is provided so that on application of an
electric
field to the second contact layer charge carriers of a second type are
injected into
the semiconductor particulate through the conductive carrier material. As
shown
in Figures 114 and 115, the randomly dispersed particulate within a carrier is
contained within a vessel and may be extruded to form an emissive fiber. The
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fiber is formed, for example, in a manner similar to the formation of
monofiliment
fishing line. The particulate/carrier mixture exits the vessel through an exit
port
and, may then be subjected to an aligning field so that the particulate is
aligned
prior to the carrier being hardened. The semiconductor particulate may
comprise
at least one of an organic and an inorganic semiconductor. The particulate can
include an organic light active particulate including at least one conjugated
polymer. The conjugated polymer has a sufficiently low concentration of
extrinsic charge carriers so that on applying an electric field between the
first and
second contact layers to the semiconductor particulate (through the conductive
carrier material) the second contact layer becomes positive relative to the
first
contact layer and charge carriers of said first and second types are injected
into the
semiconductor particulate. The injected charge carriers combine to form in the
conjugated polymer charge carrier pairs which decay radiatively so that
radiation
is emitted from the conjugated polymer. The organic light active particulate
can
include particles including at least one of hole transport material, organic
emitters,
and electron transport material. The organic light active particulate can
include
particles including a polymer blend. The polymer blend includes an organic
emitter blended with at least one of a hole transport material, an electron
transport
material and a blocking material. Depending on the phrasing, the emitter can
be
considered an electron transport material and/or a blocking material, etc. The
salient point being the formation of a particulate that is capable of photon
emission in response to an applied voltage. The organic light active
particulate
may comprise microcapsules including a polymer shell encapsulating an internal
phase. The internal phase may comprise, for example, a polymer blend including
an organic emitter blended with at least one of a hole transport material, an
electron transport material and a blocking material. The conductive carrier
material may comprise a binder material with one or more characteristic
controlling additives. The characteristic controlling additives are a
particulate
and/or a fluid and may include a dessicant; a conductive phase, a
semiconductive
phase, an insulative phase, a mechanical strength enhancing phase, an adhesive
enhancing phase, a hole injecting material, an electron injecting material, a
low
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work metal, a blocking material, and an emission enhancing material. For
example, a low work function metal particulate can be included as a
characteristic
controlling material within the carrier material andlor as a constituent of
the
emissive particulate.
The light active fiber can be used, for example, in lighting, light-to energy
devices, displays (as described below) or other uses. For example, the fiber
can
be an active component in a light fiber data transmission line. A section of
the
light active fiber which converts light to energy can be provided for
receiving a
Iight signal and converting it into electrical energy. This electrical energy
can be
amplified and used as a signal to drive another section of light active fiber
which
is emissive. In this way, along the pathway of the light fiber data
transmission
line, the inventive light active fiber can be used to amplify the signal and
improve
transmission quality and distance.
Figure 118 is a cross sectional schematic view illustrating an extruded light
active
fiber having a conductive electrode core and a transparent electrode coating.
Figure 119 is a perspective schematic view illustrating the extrusion of the
light
active fiber having a conductive electrode core and a transparent electrode
coating. Figure 120 illustrates an extruded light active fiber having a
conductive
electrode core and a transparent electrode coating connected with a voltage
source. The first and the second contact may comprise a first conductive
member
disposed longitudinally within the elongated hardened conductive carrier
material.
The other of the first and the second contact may comprise a second conductive
member disposed adjacent to the first conductive member so that at least a
portion
of the semiconductor particulate is disposed between the first conductive and
the
second conductive member. The first conductive member may be a conductive
material comprised of at least one of a metal and a conductive polymer
disposed
in the interior of the elongated hardened conductive carrier material; and the
second conductive member comprises a conductive material comprised of at least
one of a metal and a conductive polymer disposed as a coating on the exterior
of
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the elongated hardened conductive carrier material. Further, the composition
of
the particulate and the carrier can be tailored depending on the desired OLED
characteristics. The particulate can include a mixture or single component of
organic and inorganic emitter(s), hole transport, blocker, electron transport,
and
performance enhancing materials. Also, the carrier can include a mixture or
single component of organic and inorganic emitter(s), hole transport, blocker,
electron transport, and performance enhancing materials. Additional layers can
be
formed between the electrodes and the particulate/carrier layer. These
additional
layers can include a mixture or single component of organic and inorganic
emitter(s), hole transport, blocker, electron transport, and performance
enhancing
materials.
Figure 121 is a cross sectional schematic view illustrating the extrusion of
light
active ribbon having aligned OLED particulate. Figure 122 is a perspective
schematic view illustrating the extrusion of light active ribbon. Figure 123
is a
segment of extruded light active ribbon. Figure 124 is a cross-sectional view
of
the segment of extruded light active ribbon having wire electrodes
incorporated
within the ribbon and driven by a voltage applied between electrodes. The
extruded shape and orientation of the aligned particulate can be controlled
depending on desired characteristics of the light active fiber.
Figure 125 illustrates a light active fiber extrusion and chopping mechanism
for
forming uniform lengths of OLED light active fiber. In this case, the extruded
fiber can be formed and chopped into uniform lengths. These lengths can be
dispersed within a carrier and become the particulate in the
particulate/carrier
mixture disclosed herein.
Figure 126 illustrates OLED light active fiber randomly dispersed between two
electrodes. Figure 127 illustrated the OLED light active fibers aligned
between
the two electrodes. Figure 128 illustrates OLED light active fibers randomly
dispersed between two electrodes having a gap distance close to the uniform
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length of the fibers. Figure 129 illustrates the OLED light active fibers
aligned
between the two electrodes having a gap distance close to the uniform length
of
the fibers. As shown elsewhere herein, in accordance with the present
invention,
emissive particulate dispersed within a carrier can be used to form an organic
light
active device. In accordance with this embodiment, the emissive particulate
can
be elongated fiber having the composition described herein. The advantages of
the elongated particulate can be the formation of light channels within the
carrier.
These light channels may be effective for increasing the efficiency and/or the
display or device qualities.
Figure 130 illustrates light active fibers woven into carpeting. Figure 131
illustrates a light active cloth weave. The light active fiber described
herein can
be spun into thread then woven into yarn. These light active threads and yarn
can
be formed into various articles, including carpeting, wall hangings, clothing
and
other like articles.
Figure 132 illustrates a curved large format surround display formed in
accordance with the present invention by tiling length of display sections.
One of
the many advantages of a flexible display is the ability to create a wrap
around
display and provide more complete immersion within the display content. In
accordance with the present invention, the length of display that can be
fabricated
is extremely long due to the roll-to-roll fabrication processing. By tiling
strips of
roll-to-roll fabricated displays together, large format, surround displays can
be
obtained.
Figure 133 illustrates a method of forming a two layer ultra-thin mufti-
layered
OLED fiber by drawing and thinning. Figure 134 illustrates a method of forming
four layer ultra-thin mufti-layered OLED fiber by drawing and thinning. By
pulling the constituent OLED materials into fibers through a die (if
necessary) and
adjacent to each other a mufti-layer thin fiber can be formed. Electrode
layers can
be simultaneously formed, later coated or otherwise applied, or the mufti-
layered
fiber can be particlized to form the particulate of the inventive
particlelcarrier
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mixture. The particlization can include low temperature to improve the
process.
Further, another method for making the particles is to form layers of the
constituent OLED materials on a slippery surface, such as a teflon surface, or
a
smooth surface, such as glass, and then scrap the layers and chop the
scrapping, as
necessary into particles or fibers.
Figure 135 is a cross sectional view showing a wire having an electron
transport
coating layer. Figure 136 is a cross sectional view showing a wire having a
hole
transport coating layer. Figure 137 illustrates coated wire intersecting
electrodes
for forming light emitting pixels at the intersections. By coating appropriate
electrode wires, and then intersecting the coated wires, the OLED layered
stack
can be obtained at the wire intersection. These wires can then be driven to
form a
display or light.
Figure 138 illustrates the inventive OLED particulate/conductive carrier
mixture
formulated for being formable into useful products through plastic molding
techniques. The carrier material can be composed so that it is formable into
items
using conventional plastic molding techniques, such as injection or vacuum
molding. The particulate can be aligned, or remain random, while the carrier
is
fluid, depending on the desired characteristics of the molded device. In
accordance with this aspect of the present invention, an injection moldable
light
active material is provided comprising: a semiconductor light active
particulate
dispersed within a hardenable carrier material. The semiconductor light active
particulate may include at least one of an organic and an inorganic
semiconductor.
The organic light active particulate can include particles including at least
one of
hole transport material, organic emitter, and electron transport material. The
organic light active particulate can include particles including a polymer
blend.
The polymer blend may include an organic emitter blended with at least one of
a
hole transport material, an electron transport material and a blocking
material.
Additional organic emitters can be included within the polymer blend. The
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organic light active particulate can comprise microcapsules including a
polymer
shell encapsulating an internal phase comprised of a polymer blend.
The carrier material can be a haxdenable binder material with one or more
characteristic controlling additives. The characteristic controlling additives
may
include at least one of a particulate and a fluid. The characteristic
controlling
additives may include a dessicant, a scavenger, a conductive phase, a
semiconductive phase, an insulative phase, a mechanical strength enhancing
phase, an adhesive enhancing phase, a hole injecting material, an electron
injecting material, a low work metal, a blocking material, and an emission
enhancing material. The particulate may include at least one of an organic
emitter, an inorganic emitter, hole transport material, blocker material,
electron
transport material, and performance enhancing materials. The carrier may
include
at least one of an organic emitter, an inorganic emitter, hole transport
material,
blocker material, electron transport material, and performance enhancing
materials (e.g., the characteristic controlling additives).
In accordance with the present invention, the injection moldable light active
material can be provided wherein the semiconductive light active particulate
is
comprised of first emitting particles for emitting a number of photons of a
first
color in response to a first turn-on voltage applied to the electrodes and
emitting a
different number of photons of the first color in response to other turn-on
voltages. The semiconductive light active particulate may further include
second
emitting particles. The second emitting particles emit a number of photons of
a
second color in response to a second turn-on voltage and a different number of
photons of the second color in response to other turn-on voltages. By this
composition and construction, a mufti-colored light active material is
obtained.
The particulate can be composed so as to have a first end having an electrical
polarity and a second end having an opposite electrical polarity. The
particulate is
alignable within the conductive carrier so that charge carriers of a first
type are
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more easily injected into the first end and charge carriers of a second type
are
more easily injected into the second end.
Figure 139 illustrates an inventive OLED solid state light having a
conventional
light bulb form factor. Global lighting is currently a 40 billion dollar
industry
world-wide,
posting sales of over 12 billion a year. The U.S. Dept. of Energy predicts
that
LED's will account for 20°l0 of all illumination by 2010, and slash
energy use
worldwide 10% by 2025. The inventive OLED solid state Iight can include a self
IO contained voltage converter so that a conventional light bulb form factor
can be
used, and the OLED solid state light easily substituted for the convention,
inefficient, light bulb.
Figure 140 illustrates a step of spray painting a reflective conductive layer
of an
OLED device. Figure 141 illustrates a step of spray painting an emissive layer
of
an OLED device. Figure 142 illustrates a step of spray painting a transparent
electrode of an OLED device. A reflective electrode can be applied or sprayed
onto a surface to form a first electrode. A particulate/carrier mixture can
next be
sprayed or rolled over the first electrode layer. The carrier can be composed
of a
solvent and material having an adhesive quality so that the mixture acts Iike
a
conventional spray paint. A second electrode can be formed over the
particulate/carrier mixture. Appropriate contact lands and insulative
components
are also applied to drive the electrodes so that the light active particulate
emits
radiation, and/or converts light to energy.
Figure 143 illustrates a step in an inventive method for making a light active
device showing a Iight active mixture disposed between an x and y electrode
grid.
In accordance with another aspect of the present invention, a method is
provided
for making a light active device. A mixture is provided containing a monomer
and light active material. The light active material contains at least one of
an
energy-to-light material for emitting light in response to an applied
electrical
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energy and a radiation-to-energy material and generating electrical energy in
response to irradiation.
In accordance with the present invention, a light active device is
manufactured
using a self-assembly technique. Light active material is provided in a first
region. A polymer is provided in a second region. The polymer is formed by
selectively cross-linking a monomer from a mixture containing the monomer and
the light active material. The selective cross-linking causes a concentration
of the
light active material at the first region and a concentration of the polymer
at the
second region. A first electrode and a second electrode may be provided having
the polymer and the light active material disposed there between.
The light active material may be organic light emitting diode material for
emitting
light when a voltage is applied to the first electrode and the second
electrode. The
light active material may comprise inorganic light emitting diode material for
emitting light when a voltage is applied to the first electrode and the second
electrode. The light active material may comprise a radiation-to-energy
material
for generating an electrical current in response to radiation, depending on
the
intended use, the radiation may be in the visible and/or invisible spectrum.
The light active material may comprise an organic light active material
including
at least one conjugated polymer. The conjugated polymer having a sufficiently
low concentration of extrinsic charge carriers so that on applying an electric
energy to the light active material charge carriers are injected into the
light active
material and combine to form in the conjugated polymer charge carrier pairs
which decay radiatively so that radiation is emitted from the conjugated
polymer.
The light active material may comprise an organic and/or an inorganic
semiconductor. The light active material may comprise organic particles
including a polymer blend. The polymer blend can be an organic emitter blended
with at least one of a hole transport material, an electron transport
material; a
blocking material and a liquid crystal. The light active material can be
provided as
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nanostructures, and could include molecules synthesized having constituent
parts
that provide different functionality to the nanostructure. For example, a
liquid
crystal molecule can provide alignment and migration properties, a chromophore
molecule can provide light emission properties, and a cross-linkable monomer
can
provide selective hardening and migration properties.
The light active material may comprise microcapsules including a polymer shell
encapsulating an internal phase including an organic emitter. The mixture may
also include characteristic controlling additives. The characteristic
controlling
additives may include, for example, a dessicant; a conductive phase, a
semiconductive phase, an insulative phase, a mechanical strength enhancing
phase, an adhesive enhancing phase, a hole injecting material, an electron
injecting material, a low work metal, a blocking material, an emission
enhancing
material and a liquid crystal.
Figure 144 illustrates another step in the inventive method for making a light
active device, showing a polymerizationlmigration step. The monomer is
selectively cross-linked in a pattern to form a polymer. As the cross-linking
reaction progresses, the monomer migrates in response to the selective cross-
linking pattern, causing the cross-linked monomer (a polymer) and the light
active
material to become concentrated in separate regions. Figure 145 illustrates
another
step in the inventive method for making a light active device, showing an
aligning
step. The end result is a solid polymer with light active regions embedded in
a
pattern corresponding to the selective cross-linking pattern.
Figure 146 illustrates another step in the inventive method for making a light
active device, showing a controlled pixelated light emission. The mixture may
be
disposed between a first electrode and a second electrode, which may form the
electrode grid of a pixilated display or light sensor. The light active
material may
comprise organic light emitting diode material for emitting light when a
voltage is
applied to the first electrode and the second electrode. The light active
material
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may comprise inorganic light emitting diode material for emitting light when a
voltage is applied to the first electrode and the second electrode. The light
active
material may comprise a radiation-to-energy material for generating an
electrical
current in response to radiation in the visible spectrum, andlor it may be
responsive to radiation in the invisible spectrum, such as x-ray, ultraviolet
or
infrared radiation.
Figure 147 illustrates a step in an inventive method for making a light active
device, showing a bottom substrate having a bottom electrode pattern formed
thereon. In accordance with another aspect of the present invention, a method
is
provided for making a light-emitting device. The inventive steps include
providing a bottom substrate, with a bottom electrode over the bottom
substrate.
Figure 148 illustrates another step in the inventive method for making a light
active device, showing a light active mixture disposed at a light active layer
over
the bottom electrode pattern. An emissive layer is disposed over the bottom
electrode. The emissive layer includes a mixture of a dispersed OLED
particulate
in a monomer fluid carrier. Figure 149 illustrates another step in the
inventive
method for making a light active device, showing the patterning of the light
active
layer by irradiation through a mask. The monomer is selectively polymerized
causing the OLED particulate to concentrate in emissive regions and the
polymerized monomer to concentrate in polymerization regions.
Figure 150 illustrates another step in the inventive method for making a light
active device, showing the migration of light active material into light
active
regions. The light active material may include at least one of an organic
emitter,
an inorganic emitter, hole transport material, blocker material, electron
transport
material, and performance enhancing materials. The particles of the light
active
material may have a first end having an electrical polarity and a second end
having an opposite electrical polarity. The particulate may be alignable
within the
carrier so that charge carriers of a first type are more easily injected into
the first
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end and charge carriers of a second type are more easily injected into the
second
end.
Figure 151 illustrates the composition of constituents in a mufti-color light
active
mixture. In accordance with the present invention, energy-to-light, or light-
to-
energy material can be a constituent of, or be formulated as, a cross-linkable
monomer material. As shown in Figure 151, red, green and blue emissive
components can be associated with respective monomers or hardenable material,
each having a specific polymerization parameter such as a wavelength or
radiation, a catalyst, a temperature, or the like.
The light active material may comprise first emitting particles emitting a
number
of photons of a first color in response to a first turn-on voltage and
emitting a
different number of photons of the first color in response to other turn-on
voltages. The light active material may further comprise second emitting
particles. The second emitting particles emitting a number of photons of a
second
color in response to a second turn-on voltage, and a different number of
photons
of the second color in response to other turn-on voltages. The light active
material may further comprise third emitting particles. The third emitting
particles emitting a number of photons of a third color in response to a third
turn-
on voltage applied to the electrodes and a different number of photons of the
third
color in response to other turn-on voltages.
As shown in Figures 152-155, the inventive method can be used to form a full
color light active device. As shown in Figure 152, the inventive method for
making a mufti-color light active device includes disposing a mufti-color
light
active mixture disposed over a patterned bottom electrode grid. Red, green and
blue emissive components can be associated with respective monomers or
hardenable material, each having a specific polymerization parameter such as a
wavelength or radiation, a catalyst, a temperature, or the like. The emissive
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components can also be associated with a migration assisting material, such as
a
liquid crystal.
Figure 153 illustrates a step in the inventive method for making a mufti-color
light
active device, showing the selective patterning of one of the color light
active
regions. In this case, the red emissive components migrate into rows (or into
pixels) by the selective patterning and polymerization of monomerl associated
with the red emissive component.
Figure 154 illustrates a step in the inventive method for making a mufti-color
light
active device, showing the patterned color light active regions. As shown,
when
the mixture is irradiated through the patterned mask, at the bright regions in
the
pattern, the monomerl undergoes polymerization. As the polymerization reaction
progresses, monomerl and the red component migrates from the dark regions to
the bright regions, causing the other components, green and blue, to become
concentrated in the dark regions. The end result is a solid polymer containing
the
red emissive component formed in the selective pattern.
Figure 155 illustrates a full-color light active device having red, green and
blue
side-by-side patterned color light active regions. By patterning and
irradiating the
mixture in a manner similar to the patterning of the red component, the green
and
blue components are formed into rows. A fourth monomer (not shown), having
yet another polymerization parameter can also be included which is then
polymerized between the emissive rows.
Figure 156 illustrates a step in an inventive method for making a pixilated
light
active device; showing a mixture of light active material disposed over a
patterned
bottom electrode grid. A mixture containing a light active material, such as
an
emissive particulate (ep) dispersed in a monomer carrier. The monomer may be
selectively polymerized using a radiation source transmitted through a
patterned
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mask to form light and dark regions corresponding to the polymerization
regions
and the emissive regions. Figure 157 illustrates another step in the inventive
method for making a pixilated light active device, showing selective
patterning
through a pixel grid mask. The emissive regions can be formed into individual
pixels surrounded by the polymerization regions. Figure 158 illustrates
another
step in the inventive method for making a pixilated light active device,
showing
the migration of light active material to pixel regions. The patterned mask
includes at least one of the bottom electrode and a top electrode provided
over the
emissive layer.
Figure 159 illustrates the composition of constituents in a light active
device
having pixels and conductive pathways formed by a self-assembly process. The
light active materials, such as emissive components (ep) can be associated
with a
monomer or hardenable material, each having a specific polymerization
parameter
such as a wavelength or radiation, a catalyst, a temperature, or the like. Or,
the
light active material can be associated with a migration facilitating
material, such
as a liquid crystal, magnetic, paramagnetic or electrostatic material. A
conductive
material (C) can also be provided. The conductive material can be associated
with
another or hardenable material, each having a specific polymerization
parameter
such as a wavelength or radiation, a catalyst, a temperature, or the like. Or,
the
light active material can be associated with a migration facilitating
material, such
as a liquid crystal, magnetic, paramagnetic or electrostatic material.
Figure 160 illustrates a step in an inventive method for making a light active
device having pixels and conductive pathways formed by a self-assembly
process.
A light active mixture is disposed over a bottom electrode formed on a
substrate.
Figure 161 illustrates another step in the inventive method for making a light
active device by self-assembly, showing the selective patterning of the
conductive
pathways by irradiation through a mask. A non-conductive monomer (not shown)
can be selectively patterned into the emissive regions to form conductive
pathways between the polymerization regions. The conductive pathways can form
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an electrode grid of a display device. The mixture can further include a
conductive
material capable of being patterned into the conductive pathways. Figure 162
illustrates another step in the inventive method for making a light active
device by
self-assembly, showing the patterned conductive pathways. The conductive
components ((ep) and (C)) patterned into the conductive pathways.
Figure 163 illustrates another step in the inventive method for making a light
active device by self assembly, showing the selective patterning of pixel
regions
by irradiation through a mask. The monomer can be polymerized under a first
polymerization condition such as a first irradiation wavelength, temperature
or
other polymerization causing parameter. The conductive material can include a
second monomer capable of being polymerized under a second polymerization
condition, such as a second irradiation wave- length, temperature or other
polymerization causing parameter. Figure 164 illustrates another step in the
inventive method for making a light active device by self-assembly, showing
the
patterned pixel regions and conductive pathways. The emissive particulate and
the conductive material can be patterned in the conductive pathways by
selectively polymerizing the conductive material, causing the emissive
particulate
to concentrate in emissive pixels and the conductive material to concentrate
in
non-emissive regions between the emissive pixels. An aligning field can be
applied during the polymerization step or other time when emissive or light
active
particulate is able to migrate. The aligning field can be magnetic or
electric, and
the patterned electrodes can be used to define the aligning fields.
Figure 165 schematically illustrates a light active device made by self
assembly,
showing emissive/more conductive zones, non-emissive/more conductive zones
and non-emissive/less conductive zones. The light active particulate can
include a
liquid crystal constituent and a chromophore constituent. A top electrode over
the
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emissive layer, the top electrode can be patterned into an electrode grid so
that the
device acts as a pixilated display or light sensor. At least one performance
enhancing layer (not shown) can be provided between the bottom substrate and
the emissive layer. This performance enhancing layer can include, for example,
a
light absorbing or reflecting layer, a charge injection inhibiting or
facilitating
layer, and/or a barrier layer for preventing the ingress of, for example,
moisture or
oxygen. In accordance with the invention, a light-emitting device can be
manufactured using self-assembly techniques. A bottom substrate is provided
and
a bottom electrode provided over the bottom substrate. An emissive layer
comprising a mixture including an emissive/more-conductive material and a non-
emissive/less-conductive material is disposed over the bottom substrate. The
mixture is selectively patterned causing the emissive/more-conductive material
to
concentrate in emissive regions and the non-emissive/less-conductive material
to
concentrate in non-emissive regions.
Figure 166 illustrates a cubic volume of a randomly dispersed light active
material
in a light polymerizable monomer carrier. A mixture of a light active material
and
a light polymerizable monomer fill a volume. The mixture is irradiated with
two
or more laser beams. The laser beams are aligned and polarized to generate a
specific holographic interference pattern having alternating dark and light
areas.
Figure 167 illustrates the cubic volume shown in Figure 166, showing the light
active material and polymerized carrier after holographic patterning using an
interference pattern generated by laser beams. At the bright regions in the
pattern,
the monomers undergo polymerization. As the polymerization reaction
progresses, the monomer migrates from the dark regions to the bright regions,
causing the light active material to become concentrated in the dark regions.
The
end result is a solid polymer with droplets of liquid crystal embedded in a
pattern
corresponding to the dark regions of the holographic interference pattern.
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Thus, in accordance with the present invention, a laser interference pattern
can be
used to selectively pattern the mixture to form a three dimensional
arrangement of
light and dark regions corresponding to the non-emissive regions and the
emissive
regions. The three-dimensional pattern can be used to selectively pattern the
mixture to form a three dimensional structure containing the light active
material
(ep), and may also include other components, such as the conductor material
(C)
not shown, making a desired pattern of conductive pathways and emissive
material within the mixture volume. The emissive regions are formed into
individual pixels surrounded by the non-emissive regions. The mixture can
further comprise a non-emissive/more-conductive material. The emissive/more-
conductive material and the non-emissive/more-conductive material can be
patterned into conductive pathways between the non-emissive regions. The
emissive/more-conductive material and/or the non-emissive/more-conductive
material can include a liquid crystal constituent.
With respect to the above description, it is realized that the optimum
dimensional
relationships for parts of the invention, including variations in size,
materials,
shape, form, function, and manner of operation, assembly and use, are deemed
readily apparent and obvious to one skilled in the art. All equivalent
relationships
to those illustrated in the drawings and described in the specification are
intended
to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles
of the
invention. Further, since numerous modifications and changes will readily
occur
to those skilled in the art, it is not desired to limit the invention to the
exact
construction and operation shown and described. Accordingly, all suitable
modifications and equivalents may be resorted to, falling within the scope of
the
invention.
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