Note: Descriptions are shown in the official language in which they were submitted.
CA 02280022 1999-07-28
Patent Application
of
W. Steve G. Mann
for
CONTACT LENS FOR THE DISPLAY OF INFORMATION SUCH AS
TEXT, GRAPHICS, OR PICTURES
of which the following is a specification:
FIELD OF THE INVENTION
The present invention pertains generally to a data display that provides the
wearer
with a view of a computer screen, text, graphics, picture data, or the like.
BACKGROUND OF THE INVENTION
In photography (and in movie and video production), it is desirable to capture
events in a. natural manner with minimal intervention and disturbance. Thus a
display
device that will show pictt.ire information (motion pictures, still pictures,
etc.) is of
great use. Other hinds of data are also useful. For exannple, it is useful to
be able to
look up the book value of a used car while negotiating with a possibly
dishonest used
car salesman, or to consult legal documents while talking with a corrupt
politician.
Current state-of-the-art data displays a,re cumbersome, and, at the very
least,
create a visual disturbance to others. The act of looking at such displays
attracts
considerable attention, whether looking clown at a handheld display, or
bringing a
device such as an eyes°up viewfinder ttp to the eye. Even if the size
of the device could
be reduced to the point of being negligible (e.g. no bigger than the. just the
eyecup
portion of a typical camera viewfinder, for example), the very gesture of
holding a.
device up to, or bringing a. device up to the eye is unnatural and attracts
considerable.
attention, creating a disturbance to normal activities.
CA 02280022 1999-07-28
Wearable displays such as virtual reality headsets, and their portable
counterparts
(smaller and lighter monocular displays) still obstruct natural eye contact,
and are
still obvious to others.
Moreover, there a,re numerous people who don't like the idea of wearing
eyeglasses,
no matter how lightweight. Therefore adding further weight to eyeglasses is
unaccept-
able for a large number of people, especially those who don't like wearing
eyeglasses
to begin with.
SUMMARY OF THE INVENTION
Accordingly, the present invention in one aspect comprises a contact lens with
diffractor and orienter, so that the orienter will keep the diffractor
oriented the right
way, allowing the wearer of such a contact lens to see display data, text,
graphics, pic-
tures, or the like, while maintaining full eye contact with another person.
Preferably
the orienter is a weighting in the contact lens so that gravity will tend to
keep it ori-
ented in a particular way. Preferably the diffractor is a holographic optical
element,
e.g. a. diffraction grating. Preferably the diffraction grating is of the
Leith Upatnieks
variety, e.g. one that is an off axis transmission hologram (formed by having
the
object and reference beams on the same side of the contact lens during
construction.
Preferably the contact lens will diffract light arriving from approximately 45
degrees
off-axis, from a. special monochromatic display device, such that the light
will bend
directly onto the optical axis, so that a.n image of the display device will
appear
directly in front of the wearer of the contact lens.
According to another aspect of the invention, there is provided a diffractor
com-
prising a superposition of a plurality of sets of fringes, one for each of a
plurality of
colour channels. Preferably there are three colour channels, one for each of
red, green,
and blue.
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CA 02280022 1999-07-28
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BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in more detail, by way of examples which
in no way are meant to limit the scope of the invention, but, rather, these.
examples
will serve to illustrate the invention with reference to the accompanying
drawings, in
which:
FIG. 1 illustrates the use of the Contact Display while the wearer maintains
eye
contact with another person.
FIG. 2a illustrates the manufacture of the Contact Display lens with no change
in focus (only change in direction).
FIG. 2a illustrates the manufacture of the Contact Display lens with change in
focus (to help the wearer focus on closer objects, or to make the image
severely out
of focus in the case of a teleview type display system).
FIG. 3 shows the problem of colour abasing, so that the reader can better
under-
stand low it Inav be overcome with a. trichrornatic displa,v system.
FIG. 4 illustrates how three sets of hinges are superimposed into a single
contact
lens during manufacture.
FIG. 5 shows an embodiment of the Contact Display with a contact lens that is
only diffractive in the central region, so that it does not appreciably cloud
the wearer's
vIS10I1.
FIG. 6 shows the teleview display that is based on a contact lens with change
of
focus so severe that light is extremely out of focus to the extent that a
large circle
of confusion results, with the display of data appearing sharply defined
within this
circle of confusion.
FIG. 7 shows an embodiment of the teleview display where there are multiple
output beams so that the user can choose to look into any one of these to
experience
a large blurry circle of confusion in which t;he sharp well defined image data
appears.
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CA 02280022 1999-07-28
FIG. 8a shows an electromagnetically powered contact lens.
FIG. 8b shows the schematic and timing waveforms of the electromagnetically
powered contact lens.
FIG. 8c shows a photonically powered contact lens.
FIG. 8d shows the schematic and timing waveforms of the photonica,lly powered
contact lens.
FIG. 9a shows a photonically powered contact lens driven by a light source con-
cealed in a baseball cap.
FIG. 9b shows a photonically powered contact lens driven by a light source con-
cealed in a. eyeglasses worn in addition to the contact lens, where the
eyeglasses also
contain an eye tap camera,.
FICx. 9c shows a. photonically powered contact lens driven by a. light source
also
bearing information to which a spatial light modulator inside the contact lens
is
sensitive.
FIG. 9d shows a. photonically powered contact lens clock.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the invention shall now be described, in detail, with reference to the
pre-
ferred embodiments shown in the drawings, it should be understood that the
descrip-
tion is not to limit the invention only to the particular embodiments shown
but rather
to cover all alterations, modifications and equivalent arrangements possible
within the
scope of the appended claims.
When it is said that object "A'' is ''borne" by object "B", this shall include
the
possibilities that A is attached to B, that A is bonded onto the surface of B,
that A
is imbedded inside B, that A is part of B, that; A is built into B, or that A
is B.
FIG. 1 is a diagram depicting a contact lens 100 incorporating a diffractor.
The
optical axis 101 of the contact lens 100 defines the central axis of sight
102. In this
way, the. optical axis 101 of lens 100 is assumed to correspond approximately
with
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CA 02280022 1999-07-28
the optical axis of the eye 110 of the wearer of the contact lens, a,nd thus
both are
denoted as common optical axis 101.
Rays of incoming light 102 entering the eye pass through contact lens 100 and
are
not appreciably affected or distorted by contact lens 100. Likewise, rays of
light 103
leaving the eye of the wearer can be seen by another person 104, so that the
other
person 104 does not see anything unusual in the appearance of contact lens
100.
While the wearer of contact lens 100 is looking straight ahead, he or she can
also
see the screen of a handheld device 130, held downard and in front of the
wearer
of lens 100 by the wearer of lens 100. The screen of handheld device 130
comprises
backlight 131 and spatial light modulator 132. Backlight 131 may be
switcha.ble from
regular white light to coherent red laser light or other narrowband light,
typically
red or green, during off axis covert viewing as depicted in Fig 1.
Alternatively, a
red filter 1:33 may be disposed on the sv.irface of the screen of the handheld
device
130. In either case, a point 140 on the screen of device 130 radiates light in
various
directions. Some of these rays 141 of light go from point 140 to contact lens
100, a,nd
shine through contact lens 100. C'on tact lens 100 contains a diffractor,
comprising
fringes 120 that diffract the particular wavelength of light of rays 141, so
that rays
141 bend when passing through contact lens 100 a.nd emerge as diffracted rays
142.
These ra,y-s 142 are focused by the lens 111 of eye 110 onto a. point on the
retina 143.
Thus the point 140 of illumination on the display of device 130 is imaged as a
point
on the retina 143, and appears superimposed upon the center of the wearer's
field of
view superimposed on the. image of the person 140.
Another point 150 on the display of device 130 also produces rays 1.50 of
light,
some of which pass through contact lens 100 and are diffracted to emerge as
rays 152,
focused by the lens 111 of eye 110, to form a point 153 on the retina of eye
110.
Obviously Fig 1 is not drawn to scale. Eye 110 is enlarged relative to person
104.
Also the fringes 120 are enlarged relative to a wavelength of red light, or
the. like,
etc.. Subsequent figures in this disclosure are also not necessarily drawn to
scale for
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CA 02280022 1999-07-28
similar and obvious reasons.
FIG. 2 depicts a manufacture of lens 100 in a one-off process. Rays of light
200
from a wavefront of light 201 are made to interfere with rays of light 210
from a
wavefront 211. Rays 200 and rays 210 are preferably from a laser light source,
and
are both derived from the same light source, with path length difference well
within
the coherence length of the laser (preferably path lengths are approximately
equal).
Rays 200 a,nd 210 interfere in lens 100 to form fringes 120.
Lens 100 may be made from or contain a photopolymer. A satisfactory polymer
is the DuPont Photopolymer, which is exposed to laser light to establish the
fringes,
and then cured under ultraviolet light. Because the. DuPont Photopolymer may
adversely affect the mucous membranes of the eye, the contact lens is
preferably
coated with a material that prevents irritation of the eye, and also protects
the delicate
photopolymer from the cleaning solutions ordinarily used with contact lenses.
Contact lens 100 may include the prescription of the wearer, or may have a
neutral
(zero power) prescription and be used simply for a display device.
FIG. 3 shows how a secondary lens may be incorporated into the diffraction
fringes
220 formed in lens 100. Here a conjugate (virtual) rays 230 are used instead
of the
collimated rays 210 that were used in Fig 2. The virtual rays 230 are
converging rays
of light, so that their conjugate would be diverging rays of light from a
display device
at possibly very close range. Thus fringes 220 embody a holographic optical
element
that focuses light in addition to bending light through an angle of
approximately 45
degrees along the central optical axis.
hl ote that the holographic lens is separate from the functionality of the
prescription
of the contact lens, in the sense that the contact lens 100 may have zero
power
prescription and yet there may still be a diffraction lens incorporated into
fringes
220. Conversely, contact lens 100 may have a very strong refractive
prescription
together with a weaker diffractive lens. Since the two can be varied
separately, it is
possible to design a contact lens that allows the wearer to focus on near
objects such
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CA 02280022 1999-07-28
as a handheld display and simultaneously focus on distant objects such as
people
behind a counter at a i.ised car sales desk. In this sense the refractive
component of
lens 100, together with the effect of lens 111 of eye 110 might, for example,
focus
at distance of 2 or .'3 meters. while at the same time, the eye 110 is
simultaneously
focused by the. diffrac-five component of lens 100 which, when taken together
with the
overall effects of lens 100 and lens 111 of eye 110 gives rise to a sharp
focus on objects
30 centimeters away and downwards at a 45 degree angle.
In this way, the wearer of the contact lens can simultaneously focus on an
object
2 or 3 meters away, directly in front of the eye, and another object 30
centimeters
away and 45 degrees downward.
FIG. 4 depicts colour abasing. A handheld device 130 with a red screen is held
in
front of the eye and 45 degrees downaward, and produces monochromatic- rays
141 of
red light. These rays 141 converge and focus on point 143 of the retina..
Hypothetically, imagine that the handheld device produced monochromatic green
light. With the same contact lens 100, having the same fringe pattern 120
designed
for red light, one would need to hold this device higher ttp than normal.
Device 330
depicts the loc-anon where one would need to hold a device that produced green
light,
in order to have monochromatic rays 341 of green light be diffracted by
fringes 120
so and be collinear with rays 142 to also form an image on the retina at point
143.
Suppose that one wishes to have a. contact lens that will work the same with
either
a red display or a green display. One. could record two sets of fringes into
the contact
lens, one set. of fringes for red light, and another finer set of fringes that
would bend
light more severely for use with a green display. Note that both sets of
fringes would
be imbedded into the contact lens, so that while using the red display, there
would
also be an additional set of fine fringes (intended for green light) that bend
red light
more severely, so there would be a double image of two red displays, one that
appears
right in front of the user, and another above it. When using the green
display, there
will be an additional set of coarse fringes (intended for red light) that will
bend green
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CA 02280022 1999-07-28
light less than the usual 45 degrees. Thus one image of the green display will
appear
directly in front of the wearer of the contact lens, and a second image of the
green
display will appear below it.
FIG. 4a depicts a set of coarse fringes 120 in a contact lens. The pitch of
these
fringes 120 is such that the diffraction grating will bend red light through
an angle
of 45 degrees.
FIG. 4b depicts a. set of medium sized fringes 420 in a contact lens. The
pitch of
these fringes 420 is such that the diffraction grating will bend green light
through an
angle of 45 degrees.
FIG. 4c depicts a set of fine fringes 4'21 in a contact lens. The pitch of
these
fringes 421 is such that the diffraction grating will bend blLie light through
an angle
of 45 degrees.
FIG. 4d depicts a set of coarse. fringes 120, a set of medium sized fringes
420, and
a set of fine fringes 421 all within the same contact lens.
With the "white." contact lens of Fig 4d, a trichromatic display may be used
to
show an image in what appears to be a white colour. Of course there will be
colour
abasing, in the sense that the fringes 120 will bend green and blue components
of the
displayT only slightly, and these will therefore appear to hover below the
white image
of the display. Likewise, fringes 4'?0 will bend red light too much and blue
light not
enough, causing coloured images to appear above and below the central white
image.
Fringes 421 will bend red a,nd green light e~:cessively, e.g. more than 45
degrees,
causing the. red and green images to appear above the central white image.
Thus the wearer of the "white" contact lens of Fig 4d, when holding a handheld
device with trichroma,tic display downward at a 45 degree angle, will see a
central
white image in a forward direction, a yellow image below it, and a red image
still
further down, a,s well as a cyan image above it and a blue image still further
up.
So long as the display subtends a. visual angle less than the angle between
abased
colours, a clearly visible white (e.g. full true colour display screen is
visible. Thus
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the apparatus of the invention can be used to give a full colour display
covertly
superimposed directly in front of the wearer, while the wearer makes full eye
contact
with another individual.
FIG. 5 depicts a contact; lens having a diffractor only in a certain region of
the
contact. lens. In this way, the slight fogging effect arising from looking
through a
diffraction grating can be minimized, without appreciably reducing the
diffraction
efficiency as might be necessary if the grating were weakened to reduce this
fogging
effect. The lens 100 has fringes 120 only in a small region, resulting in a
sharp clear
display without noticable fogging of the refractive light rays 102.
FIG. 6 depicts a contact lens display based on a teleview drive. Contact lens
100
has fringes 120 that are constructed so that they bend light arriving at the
optical
axis through an angle of approximately 45 degrees, but also so that light
arriving off
the optical axis (also from a 45 degree angle) is deflected severely from the
optical
axis. Thus lens 100 also contains the effect of a diffractive lens of very
short focal
length. This males the light rays 641 entering the contact lens apear as
severely out
of focus. Instead of focusing to a point in the eye, these rays spread out to
define a
very large cone of light 642.
A handheld drive device that may be suitable for such a contact lens display
is
shown as device 630 containing a. spatial light modulator 632, light source
635, and
optics 636. Preferably light source 635 is a red monochromatic point source. A
satisfactory monochromatic point source may be made from a laser diode and an
appropriate spatial filter. An image is projected along rays 641, and is seen
on the
retina of eye 110 as a sharply defined image within the circle of confusion
created by
the blur of rays 64'?.
The concept of a circle of confusion is well known. For example, when looking
at
a point source through an incorrect eyeglass prescription, one will see
instead a large
circle. If the prescription is more severely incorrect the circle will be
larger. This
phenomenon can be easily demonstrated and understood by wearing a. -f-25
diopter
CA 02280022 1999-07-28
contact lenses (e.g. having a focal length of 40mm) in addition to any
prescription one
normally wears. Looking outside late at night, one will see the distant light
sources
of the. city, or the like, as large circles. These are the circles of con
fuszo~z.
Ordinarily this is undesirable, but in this aspect of the invention, another
phe-
nomenon results, in which the out of focus circle of confusion of the point
source 635
reveals the. material upon spatial light modulator 632, as a sharply defined
image.
In this case, the severe misfocusing results from the diffraction grating in
lens 100,
and not from its prescription. In fact the contact lens 100 should have the
correct
prescription for the wearer, so that objects other than the light source 635
are sharp.
Preferably the misfocus is so severe that eye lens 111 is too weak to focus on
point
source 635, or bring rays 641 into focus, so that they spread out and strike
the retina
defining a large circ.ula,r dish of light. Point source 635 is typically red
or green, so
that dish of light appears as a large circle of red or green light.
The enact shape of this disk of light is determined by the shape of the
opening
in the eye, and will also show imperfections in the eye lens 111, such as dust
on eye
lens 111, or any irregularities in the eye iris of eye lens 111, blood vessels
in the eye,
as well as dust on eye lens 11.1 or contact lens 100.
Also, each time the wearer blinks, the wipe lines of the eyelids will appear
in much
the same way as the lines made by the windshield wipers on an automobile
windshield.
These wipe lines are. strangely disturbing at first, because when the wearer
tries to
look at them, they go away. Each time the eye tries to foveate on them, the
eye
moves and the eyelids wipe away the. very thing that the wearer is trying to
look at.
However, after some. getting used to, the apparatus of the invention is quite
effective
and usefwl. This kind of display in which a. sharply defined or somewhat
sharply
defined image appears within a circle of confusion will be. referred to as a.
Blurry
Information Display.
Despite these irregularities, the circular disk of light will indicate to the
wearer
the visual information present on spatial light modulator 623.
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Moreover, the colour and state of the light source 635 (e.g. whether the light
source 635 is flashing, and at what rate, and in the case of a multicolour
light source,
whether it is red or green or whichever other colours it may assume) may
convey
additional information to the wearer of the contact lens display system.
The handheld devices of the invention may also include. a camera 637 with lens
638 pointing up toward a person standing in front of the wearer of contact
lens 100.
In this way the wearer can use the contact lens display system of the
invention to aim
the camera, and compose a. picture. Even if the teleview system suffers some
blur due
to diffraction along rays 641, enough resolution will still be present to make
a good
photographic composition.
It should also be noted that the large field of view of the teleview contact
lens
display system is of great benefit, even if the implementation is poor in
terms of
resolution. For example., with an ordinary display, one will need to move the
eye
around to foveate on different parts of the. display. However, with the large
field of
view of the. teleview display system, it is not necessary look directly at
parts of the
display 1_>ecause the severe magnification makes these elements visible even
in the
periphery of the view. Therefore matters su<:h as photographic composition can
be
planned quite well without averting gaze from straight ahead a.t the subject
being
photographed.
The low camera angle. is particularly effective in shooting documentary videos
of
questionable used car salesmen, corrupt officials, or dishonest politicians.
FIG. 7 depicts a contact lens display based on a teleview drive followed by a
beam
multiplier. A beam multiplier 7 00 spreads the beam out so that in addition to
the
central image beam's rays 641, there ai°e also other beams with rays
741.
To use the apparatus, all the user has to do is move device 630 around until
it is
oriented so that any one of the beams is shining into his or her eye.
The beam multiplier 700 may be a simple diffraction grating. If properly
designed,
it will spread the beams just enough that they are densely tesselated at a
typical
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CA 02280022 1999-07-28
holding distance such as .30 centimeters, or whatever the expected distance at
which
the user will hold the device 6.30 from his or her eye.
FIG. 8a depicts an electromagnetica,lly powered contact lens. A power supply
for
the contact lens of the invention is of great use for a variety of reasons.
For example,
the diffration grating may be turned ofF using liquid crystal technology.
Similarly,
the colour of the lens may be changed rapidly, to sequence through three
different
colours, red, green, and blue, and this colour field sequencing may be
synchronized to
a. handheld device or wristworn device, so that there will be no colour
abasing when
covertly viewing the device using the contact lens display system.
A coil 800 of wire picks up alternating current electricity by way of
induction.
The wire is located in greater proportion and more heavily toward the. bottom
and
the connections to the device to be powered are made at the bottom where wires
801 contribute more to the weight at the. bottom to help contribute to or
define the
weighting that is a method of orienting the contact lens. Preferably the wire
colour
and composition is such that it matches the appearance of the eye, so that it
is not
apparent to other people looking into the wearer's eyes.
In this example., the contact lens contains two durable. glass conductive ITO
(indium-tin oxide) coatings having transmissivity in the visible region, and
typically
having resistivity in the range of 10 to 10,000 ohms~square.
The. ITO (indium-tin oxide) coating is typical of what is used in LC'Ds
(Liquid
Crystal Displays).
A first coating 810 is separated from a second coating 811 by an insulating
layer.
The. insulating la,ver contains the portion of the contact lens display that
is to be
controlled or switched. For example, in a c-olour selector, the material in
between
coating 810 and coating 811 may be driven with alternating current so that it
switches
or changes colour rapidly, for example, at 180 Hz.
In a three colour systerm, colours selected at this frequency, with proper
phase
ordering, provide red, green, and blue field sequencing.
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CA 02280022 1999-07-28
Alternatively, the diffraction effect may be switched in and out so that it is
only
on for a short time. This removes any possibility of another person detecting
the
subtle rainbow appearance typical of the contact lens displays previosly
described in
this disclosure.
FIG. 8b depicts the timing information and schematic block diagram of the elec-
tromagnetically powered contact lens. A Hand Held Device (HHD) 830 has two
antennas, a first antenna. 800 for communication with the outside world
(Internet
connection, etc..) and a. second antenna. 860 for communication with the
contact lens.
Antenna 860 is preferably a loop antenna that acts like the primary of a
transformer
of which coil 800 is the secondary. The frequency of the alternating current
may be
quite high, preferably above the range of hearing so that the acoustic.
emissions are
no detected. A satisfactory choice of frequency is 100 kHz, allowing for more
than
500 cycles per cycle of the. display update rate of 180 Hz. With a duty cycle
of 10%~
this provides 50 cycles per on period, and a. higher frequency than 100 kHz
can easily
be used if more cycles per on time are desired (e.g. for a highly resonant
power re-
ceive circuit), or if lesser duty cycles are desired. The transmitted waveform
(e.g. a
100 kHz sinusoid) is amplitude shift keyed, on and ofl~, using a waveform
having long
on periods 862 and short off periods 863. The on periods 862 cause the
diffraction
pattern to be broken up (disturbed). by the twisting of a. liquid crystal
material, away
from the way it was when the diffraction grating was formed. The off periods
86:3
allow the liquid crystal material of the contact lens to relax into its usual
state, so
that diffraction results.
A laser beam 841 in device. 830 projects an image into the eye. The laser beam
is
only on for time period 843 corresponding to when the antenna 860 is not
radiating.
If the system is running at 180 Hz, the laser will appear to the wearer as if
it were.
on constantly, but the fact that the diffractor is permitted to be switched
off (to be
active a,nd diffract) when the laser is switched on, will ensure that the
wearer cannot
focus on the laser beam. This will prevent eye damage or discomfort, and will
also
1=1
CA 02280022 1999-07-28
allow the image. to be seen in the blurry circle of confusion formed by the
out of focus
laser beam.
As a failsafe precaution, should power be lost to the transmitter or should
recep-
tion of the signal from antenna 860 falter, the contact lens will go into the
state where
it misfocuses laser light, so that the wearer will not be able to see any
laser light in
sharp focus. This will likely prevent or reduce eye damage or discomfort from
the
laser beam.
FIG. 8c depicts a photonicallv powered contact lens display system. Because
the
laser is needed for the display, it is appropriate that the display get its
power from
the laser. A lightcell 880 picks up laser light and provides power to lens
coating 810
and coating 811, by way of wires 881. A lightcell is a cell that generates
power when
light is incident upon it. An example of a lightcell is a selenium solar cell
used in
a photographic. light meter in which no battery power is required to power the
light
meter, because the selenium solar cell powers the meter movement directly.
Many
of the older fully manual cameras also contain selenium cells and therefore do
not
need a battery to power the light meter section of the camera. (Some early
automatic
cameras also used selenium cells and did not require a battery either.
Wires 881 and lightcell 880 are located at the bottom of the. contact lens for
two
reasons:
~ their weight helps orient the contact lens in the correct orientation;
~ the light is coming from below, so the lightcell is on the curved surface of
the
eye. where it will pick ttp maximum light.
In this case, the situation must be reversed, so that the desired rrtisfocus
or other
effect happens when the lens is powered. When laser 641 turns on, contact lens
100
defocuses it. Such a contact lens is useful in and of itself, for example, ~s
a. laser
safety device. Moreover, such lenses may work with teleview photonic drives
located
throughout the environment.
to
CA 02280022 1999-07-28
Preferably lightcell 880 is responsive primarily to laser light (e.g. either
responsive
mainly t.o red light, or responsive only to light that is monochromatic in
nature).
FIG. 8d depicts the timing information and schematic block diagram of the pho-
tonically powered contact lens. When laser beam 641 turns on during time 843,
the
contact lens diffracts, and when it turns off during time 842 the contact lens
does
not diffract. Note that in this case handheld device 630 does not have. or
need an
antenna. to communicate with the contact lens. Of course device 630 ma,v still
have
an antenna 850 to communicate with the outside world.
FIG. 9a depicts a photonically powered contact lens worn with a light source
in
a baseball cap 900. In this case, lightcell 880 is at the top of the contact
lens 100 to
receive light rays 141 and rays 151. Since lightcell 880 is at the top of the
contact
lens, it must be either lighter than the rnateria,l in which it is imbedded,
or there must
be another orienter in the lens 100 to keep it oriented properly.
The light source is typically a flat panel display with red backlight.
A louvre 910 prevents others from seeing the light source.
FIG. 9b depicts a photonically powered contact lens worn with eyeglasses
defined
by eyeglass frames 901. Light sensitive arrays 930 are built into the frames
901 of
the eyeglasses. Filters 940 ensure the arrays are only sensitive to red light
of a very
narrow range of wavelengths. Filters 940 also include a loi.mre selecting a
narrow
range of angular inputs. The louvre is preferably implemented as a holographic
optical element.
Eyeglass lenses 920 also function as holographic optical elements. A red
portion of
a ray of light 951 is difFiacted downward to sensor array 930 and lands on
point 953.
Point 953 results therefore in the absorption and quantification of a. red
portion of ray
951. The rest of light ray 951 continues on into the eye 110 and lands on
point 15:3 of
the retina. At the same time., the video signal from sensor array 938 is
responsive to
the light falling on point 953 of the array. The video signal from sensor
array 930 is
supplied to the contact lens display by way of point 150, where rays 151 are
therefore
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responsive to ray 952. Rays 151 therefore. enter the eye and also land on
point 153.
Thus the portion of ray 951 that was diverted from its usual path contributes
to a
perceived effect at point 153, where the nondiverted light also appears. Thus
the
diverted light and the nondiverted light meet at the same place.
An imaging system that diverts a. portion of the light that would otherwise
enter
an eye of the. user (e.g. a device that behaves as if it were a camera with
effective
center of projection that matches the center of projection the lens of an eye
of the
user) will be referred to as an Eye Tap Camera.
An optical system that directs light into the lens of an eye of the user, such
that
there exists a capability for rays of this light to be collinear with and
responsive to
corresponding rays of light diverted by an Eye Tap Camera will be referred to
as
an Eye Tap Aremac. (The word "aremac" is derived by spelling the word "camera"
backwards.)
As the wearer looks around, eye 110 will no necessarily be always pointed
straight
ahead. However, to the extent that the point 153 moves relative to the retina
when
the eye looks around in different directions, this relative movement will
affect, ap-
proximately equally, light ray 951 as well as light rays 152 arising from
diffracted rays
151. Thus a properly sustained illusory transparency will remain, where light
that is
diverted will be reconstituted in register with that which was diverted to
make it.
This process of diverting and reconstituting the light may seem fruitless, but
for
the fact that instead of simply feeding the video signal from array 930
straight into
the contact lens display system, the signal is first passed through a computer
image
processing system. Thus the. apparatus of the invention may function as a
"Reality
Mediator'', altering the perception of a portion of the wearer's visual
reality.
FIG. 9c depicts a photonically powered contact lens 100 including a defocuser
960. The defocuser 960 is, in this case an optical defoc.user. Ordinarily, an
optical
defocuser would prevent the wearer from seeing, but for the fact that in this
case,
the optical defocuses is only present over a portion of the contact lens
through which
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CA 02280022 1999-07-28
the wearer sees. Around the optical defocuser there is a non-defocused region
999
through which the wearer can see ordinary objects in an ordinary way. The
wearer
therefore sees a mixture of focused a.nd defocused light.
A concentric lightcell 880 surrounds the outermost region of the contact lens
where
the eye of the wearer is opaque, such that the light blocked by the lightcell
does not
adversely affect the wea.rer's ability to see. The lightcell 880 preferably ha-
s roughly
the same colour and shine as the brown, green, blue, or the like of the eye
(and is
therefore preferably made to match the wea.rer's particular eye).
Light cell 880 also conceals a computer or information processor 990
underneath
lightcell 880.
Wires 980 connect processor 990 to conductive transparent material 970. A sat-
isfactory material 970 is ITO. One surface of material 970 may be broken up
into
separate regions so that the computer processor 990 can separately address
each por-
tion. Wires 980 are preferably made to match the colour and shine of the
active region
(e.g. iris) of the eye where light enters. Wires 980 which extend radially
outward from
material 970 may also be randomized, in their layout, to have similar
appearance to
the eye's iris.
FIG. 9d depicts a photonically powered contact lens 100 in which there is a
clock.
Hourhand segments 996 are. addressable by processor 990. Minute - hour (minute
minus hour) hand segments 995 make up the difference between a minute hand and
an hour hand.
The time of clay is displayed by way of processor 990 selecting the
appropriate
three segments of the 24 segments in layer 970.
Additional information can be conveyed by- flashing segments, etc..
The clock is powered by any light arriving on the contact lens, and may be
viewed
whenever there is a point source of light present in the scene. For example,
at night,
looking out at the city lights, the wearer may see hundreds of tiny clocks,
one sur-
rounding each point source of light. Looking into automobile headlights will
reveal a
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CA 02280022 1999-07-28
pair of cloc.kfa,ces side by side.
During the day, the occasional glint of sunlight off a specular object will
reveal
the tune of clay.
BENEFITS OF THE INVENTION
The apparatus of this invention allows the wearer to view an information dis-
play while maintaining full eye contact with other people, without the need to
be
encumbered by cumbersome headgear or eyeglasses.
From the foregoing description, it will thus be evident that the present
invention
provides a design of a contact lens for information display. As various
changes can
be made in the. above embodiments and operating methods without departing from
the spirit or scope of the invention, it is intended that all matter contained
in the
above description or shown in the accompanying drawings should be interpreted
as
illustrative and not in a limiting sense.
Variations or modifications to the design and construction of this invention,
within
the scope of the invention, may occur to those skilled in the art upon
reviewing
the disclosure herein. Such variations or modifications, if within the spirit
of this
invention, are intended to be encompassed within the scope of any claims to
patent
protection issuing upon this invention.
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