Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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INTEGRATED MODULAR LIGHTING UNIT
FIELD OF THE INVENTION
[0001] The present invention pertains to the field of lighting systems and in
particular to an integrated modular light-emitting device lighting unit
wherein the
modular lighting unit is capable of dimming and control of light colour and
correlated
colour temperature.
BACKGROUND
[0002] Having regard to general lighting, the first Edison base type
incandescent
style lamps and all of their derivatives have remained relatively unchanged
through to
the present day. While many incremental technologies have led to the
development of
longer lived, higher efficiency, and more consistent light sources throughout
many
decades, the basic form that gave rise to the construction of a luminaire has
remained
relatively stable.
[0003] Other lamp forms are commonly seen in the lighting industry. For
example,
fluorescent lamps can provide elongated cylindrical light sources. In the case
of high
intensity discharge lamps, their shapes are often similar to the typical
incandescent lamp
with glass bulb envelopes and metal screw type bases that mate to their
respective
electrical sockets. These forms of lighting devices are ubiquitous and pervade
the
general field of lighting that represents a large global industry.
[0004] These general lamp forms are well suited to the tasks of supporting the
respective general light emitting structure or process that is preseint within
each of their
glass bulb envelopes. In particular these lamp forms can provide a protective
mechanical surrounding that prevents either the escape of internal gases
and/or the
ingress of external gases that could contaminate the interior assembly of the
la.mp,
thereby disrupting their functionality. Additionally, these forms can provide
a stable
thennal environment that contains the internal gas and maintains temperatures
at levels
conducive to light output. They can also provide a reliable and standardized
form factor
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for the provision of electrical contacts at the base or ends of a lamp, for
example they
can mate to industry standard socket forms. The Edison screw base is the most
common
form for this interface since it provides a'mechanical linkage that supports
the entire
bulb while providing a reliable and redundant metallic electrical contact at
many points
along the screw shell. These general lamp forms can additionally provide a
convenient
optical shape for light emission that is suited to the reflector geometry and
optics of the
luminaire. The oldest and simplest forms of lamps provide a roughly spherical
light
emission paitern from the filament within a glass envelope. As lamp types
evolved over
time, the bulb formats gave rise to reflectorized types of lamps that contain
an integral
reflector added inside or outside the bulb to generate a' bearn" of light, for
exarnple.
Finally these general lamp forms can provide a convenient standard quantity of
light that
is usually suited to the illumination task. Over decades lamps have remained
relatively
unchanged and certain standard sizes and wattages have emerged that are often
consistent, even from manufacturer to manufacturer. Examples include the
common 60
Watt incandescent A-style lamp, the 40 Watt T12 fluorescent lamp and the 250
Watt
high pressure sodium lamp, wherein each of these devices has evolved to suit
specific
types of luminaires, applications and/or markets.
[0005] With the emergence of competitive light-emitting diode (LED)
technologies
that already surpass the performance of almost all.incandescent lamps in both
electrical
efficiency and life expectancy, industry forecasts predict that a performance
of 150
lumens per watt and even 200 lumens per watt are possible from LEDs. These
figures
easily surpass today's conventional white light sources that generate light
with less than
1001umens per watt. In view of the fact that the single greatest cost of
ownership of any
given lamp is its electrical consumption over its life, the LED can provide a
strong
economic case.
[0006] One of the key challenges for LEDs to achieve wide market adoption is
the
fact that they are significantly more variable in production and do not yet
exhibit a
standardized form or structure that is conducive to general illumination
applications.
For example, raw light output from a group of LED chips grown on the same
wafer
manufactured by the same equipment may. have as much as approximately a 3:1
variation in their luminous flux output over the same wafer. This fact gives
rise to a
binning strategy which 'is commonly used in the indushy, whereby LEDs are-=----
- -------
individually tested and binncd into categories of luminous flux output that
represent
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approximately 30% intervals. Likewise, forward voltage, dominant wavelength
and
beam spread may be other factors that are considered during the binning
process.
[0007] Structurally, LEDs are often packaged into single chip packages that
are
derived from the needs of the indicator lamp market. Many of these are
designed to be
soldered to circuit boards and are designed to employ electronics
manufacturing
equipment and processes. The optics associated with these packages are often
compromised in order to provide a specific or desired beam pattern, resulting
in optical
efficiencies of less than approximately 60%. For thermal regulation, many of
these LED
packages rely on a metallic frame acting as a heat sink for cooling, although
some of the
more recent LED packages are starting to employ a thermal contact pad that is
in
intimate contact with a substrate for efficient heat transfer,
[0008] Over the years there have been a number of illumination apparatuses
that
have been designed using light emitting diodes. ln particular European Patent
No.
1,416,219 discloses an LED illumination apparatus with a connector and drive
circuit.
The connector is coupled to an insertable and removable card-type LED
illumination
source, which includes multiple LEDs that have been mounted on one surface of
a
substrate. The lighting drive circuit is electrically connected to the card-
type LED
illumination source by way of this connector. The card-type LED illumination
source
preferably includes a metal base substrate and the multiple LEDs have been
mounted on
one side of this metal base substrate. The back surface of the metal base
substrate, upon
which no LEDs have been mounted, is in thermal contact with a portion of the
illumination apparatus. A feeder terminal'to be electrically connected to the
connector is
provided on the surface of the metal base substrate on which the LEDs are
provided,
thereby enabling electrical excitation of the LEDs mounted on the card-type
element.
[0009] This European patent discloses several features of a stand-alone
lighting
apparatus; however it does not provide a means for enabling colour control,
intensity
control, thermal control or any other control of the lighting apparatus beyond
straight
electrical drive of the LEDs. Furthermore, this stand-alone lighting apparatus
is not
enabled to interact or communicate with other lighting apparatuses and
therefore
functions autonomously.
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[0010] United States Patent No. 6,617,795 discloses a multichip light-emitting
diode
package having a support member, at least two light-emitting diode chips
disposed on
the support member, at least one sensor disposed on the support member for
reporting
quantitative colourimetric information to a controller relating to the light
output of the
light-emitting diodes, and a signal processing circuit which includes an
analog-to-digital
converter logic circuit, disposed on the support member for converting the
analog signal
output produced by the sensors to a digital signal output. The issue of
protecting LEDs
from overheating is introduced and it is proposed that the use of temperature
sensors can
provide a means to monitor this parameter. However, this apparatus does not
include a
proactive means for heat removal from the device or a means for heat
regulation within
this LED package. Furthermore, while this package allows for connection to
some type
of external power supply, control or limiting of the power transmitted to the
LEDs is not
provided and therefore this apparatus may suffer from thermal and control
limitations.
[0011] A modular warning signal light system is disclosed in United States
Patent
No. 6,462,669. This warning signal light system comprises at least one support
having
at least one module receiving port arranged to receive the support engagement
member
of another module in a removable manner. Each module includes at least one
visible
side that has at least one light emitting diode light source engaged thereto.
The light
emitting diode light source, module and support are all in independent
electrical
communication with a controller. The controller is constructed and arranged to
selectively activate at least one support, at least one module, at least one
light emitting
diode light source, and any combinations thereof to create at least one
warning light
signal. This system does not however include any means for heat management and
there
is no mention of any data collection during operation in order to control a
variety of
properties relating to the funetionality of the light system and therefore
this system may
suffer from thermal and control limitations.
[0012] United States Patent No. 6,331,063 discloses an LED luminaire formed in
a
manner that a plurality of LED chips are disposed three-dimensionally on a MID
(moulded interconnection device) substrate in a rectangular plate shape. The
mounting
of three LED chips on the bottom face of respective dents provided lengthwise
and
crosswise on one surface of the MID substrate is disclosed. The LED chips are
selected
from at least two types that are mutually different in luminous colour, and it
is disclosed
as being desirable that three types, namely red, blue, and green coloured LEDs
are used.
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In this manner optional light distribution characteristics may be thereby
obtainable
depending on the configuration of the substrate and the LEDs thereon. In this
manner
different colours such as white and daylight colours of inaandescent and
fluorescent
lamps are enabled by mixing the luminous colours of the respective LED chips.
There is
however, no mention of a self-contained modular illumination unit designed to
interact
with other modular illumination units for the creation of light, and there is
also no
disclosure relating to a modular design of the lighting units.
(0013] In addition a smart light emitting diode cluster and system is
disclosed in
United States Patent No. 6,208,073. The smart cluster and system includes a
central
processing unit (CPU) and a plurality of LED cluster strings, each comprising
an LED
cluster connected in series. Each LED cluster includes an LED drive circuit
and a
plurality of LEDs, wherein the CPU receives an external input image signal,
and then
the desired control signal and image data are sent to the LED cluster strings
by
appropriate processing. The control signal is used to switch the LEDs in the
cluster in
order to generate a desired image and related colour variation. Subsequently,
the control
signal and image data are transferred to the next LED cluster by the LED drive
circuit.
In this manner, the control signal and image data are progressively
transferred from the
first to the last cluster so that an entire image with colour variation can be
displayed by
all of the LED clusters in the system. There is, however, no reference to heat
regulation
or operational feedback for the individual LED clusters and therefore this
system may
suffer from thermal and control limitations.
[0014] United States Patent No. 6,441,558 discloses a luminaire light control
system
comprising a controller system coupled to a power supply stage. The controller
is
configured to provide control signals to the power supply so as to maintain
the DC
current signal at a desired level for producing the required light output.
There is further
disclosed the use of temperature and light sensors to provide feedback
regarding the
light emitting devices, in order for the controller to maintain a desired
luminous flux
output for each of the LEDs. There is disclosed a complete luminaire system
however
there is no mention of modular units for integration and forming of a
luminaire system.
Furthermore, although this system is intended to form a complete system, there
is no
disclosure of any method or means for heat management and therefore this
system may
suffer from the heat regulation problems.
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[0015] A system for controlling the luminous intensity of light emitting
diodes is
disclosed in United States Patent No. 5,783,909. The invention comprises a
sensor for
measuring the luminous intensity of the LEDs in addition to a power supply
capable of
providing a switched electrical supply to the LEDs. The switched power supply
uses a
pulsing strategy to modulate the output to the LEDs so as to maintain a
desired luminous
intensity. This system however does not include a means for dissipating heat
from the
LEDs or any optics for colour mixing, collimation or re-direction or any
modularity of
the lighting device. This system may therefore suffer from thermal problems in
addition
to problems with the generation of substantially uniform illumination.
[0016] United States Patent No. 6,741,351 discloses a luminaire with a means
for
maintaining a desired colour balance from an array of red, green, and blue
LEDs.
Photodiodes are used to intercept a sampling of the light emitted from the
LEDs. A
method for testing the luminous flux output of each different colour is
disclosed, using a
pulsing approach where LEDs are selectively turned on and off, thereby
enabling the
light sensor to measure each LED separately. There is however no disclosure
relating to
any heat management, heat removal, or any notion of modularity of the lighting
unit for
use in a larger lighting system. This system may therefore suffer from thermal
regulation issues.
[0017] It is clear that the evolution of LED based light sources into
consistent, user-
friendly modular devices for general illumination has not yet occurred. The
prior art
discloses efforts to address some of the difficulties associated with the use
of light-
emitting devices in lighting applications such as control over intensity and
chromaticity
and removal of heat from LEDs. However, an integrated solution to satisfy
general
lighting requirements while exploiting the benefits of light-emitting devices
is presently
not available. Therefore there is a need for a new integrated modular light-
emitting
device lighting unit that can function as a single unit or in combination with
other
modular units and maintain a given intensity and chromaticity while utilizing
the
efficacy of the light-emitting devices and their lifetime, thereby providing
designers
flexibility for the design of luminaires based on light-emitting devices.
[0018] This background information is provided for the purpose of making known
information believed by the applicant to be of possible relevance to the
present
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invention. No admission is necessarily intended, nor should be construed, that
any of
the preceding information constitutes prior art against the present invention.
SITIVIIVIARY OF THE INVENTION
[0019] An object of the present invention is to provide an integrated modular
lighting
unit. In accordance with an aspect of the present invention, there is provided
an
integrated lighting module comprising: one or more light-emitting elements for
generating illumination; an optical system optically coupled to the one or
more light-
emitting elements for manipulating the illumination; a feedback system for
collecting
information representative of operational characteristics of the one or more
light-
emitting elements, said feedback system generating one or more signals
representative
of said information; a thermal management system in thermal contact with the
one or
more light-emitting elements, said thermal management system for conducting
heat
away from the one or more light-emitting elements; a drive and control system
receiving
the one or more signals from the feedback system, said drive and control
system
regulating input power and generating and sending control signals to the one
or more
light-emitting elements, said control signals generated based on predetermined
control
parameters and said one or more signals.
[0020] In accordance with another aspect of the present invention, there is
provided a
networked lighting system comprising: two or more integrated lighting modules,
each
module including; one or more light-emitting elements for generating
illumination; an
optical system optically coupled to the one or more light-emitting elements
for
manipulating the illumination; a feedback system for collecting information
representative of operational characteristics of the one or more light-
emitting elements,
said feedback system generating one or more signals representative of said
information;
a thermal management system in thermal contact with the one or more light-
emitting
elements, said thermal management system for conducting heat away from the one
or
more light-emitting elements; a drive and control system receiving the one or
more
signals from the feedback system, said drive and control system regulating
input power
and generating and sending control signals to the one or more light-emitting
elements,
said control signals generated based on predetermined control parameters and
said one
or more signals; and a communication system operatively connected to the drive
and
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control system, said communication system eiiabling communication between the
two or
more integrated lighting modules.
BRIEF DESCRIPTION OF THE FIGURES
100211 Figure 1 is a diagram of the components of the integrated lighting
module
according to one embodiment of the present invention.
[0022] Figure 2 is a diagram of the functional blocks of drive and control
system
showing the division between drive and control of the integrated lighting
module
according to one embodiment of the present invention.
[0023] Figures 3A to 3G illustrate configurations of the driver sub-module of
the
drive and control system according to embodiment of the present invention.
[0024] Figure 4 is a cross sectional view of a cloverleaf compound parabolic
concentrator (CPC) optical element of the optical system according to one
embodiment
of the present invention.
[0025] Figure 5 is a cross sectional view of a parabolic reflector optical
element of
the optical system according to one embodiment of the present invention.
[0026] Figure 6 is a cross sectional view of a segmented parabolic reflector
optical
element of the optical system according to one embodiment of the present
invention.
[0027] Figure 7 is a cross sectional view of an optical element of the optical
system
comprising a parabolic mirror and a long pass filter arrangement according to
one
embodiment of the present invention.
[0028] Figure 8 illustrates a lighting unit comprising a rnulti module QFP
("Quad
Flat Pack") package incorporating heat pipes according to one embodiment of
the
present invention.
[0029] Figure 9 illustrates an integrated modular lighting unit torchiere
according to
another embodiment of the present invention.
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[0030] Figure 10 illustrates an integrated module lighting unit luminaire
according
to another embodiment of the present invention.
[0031] Figure 11 illustrates a lighting unit comprising multiple sub-modules
of.Iight-
emitting elements according to another embodiment of the present invention.
[0032] Figure 12 illustrates lighting unit with components in a stacked
con$guration
according to another embodiment of the present invention.
[0033] Figure 13 illustrates a]ighting module according to one embodimeni of
the
present invention.
[0034] Figure 14 illustrates a lighting module according to another embodiment
of
the present invention.
-[0035] Figure 15 illustrates the lighting module according to Figure 14
wherein the
optical system has been separated from the remainder of the lighting module.
[0036] Figure 16 is a cross sectional view of a lighting module integrated
within a
housirig according to one embodiment of the present invention.
[0037] Figure 17 illustrates the lighting module according to one embodiment
of the
present invention.
[003$] Figure 18 illustrates the optica[ system of the lighting module
according to
one embodiment of the present invention.
[0039] Figure 19 illustrates a thermal management system according to one
embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0040] The term "light-emitting element" is used to define any device that
emits
radiation in any region or combination of regions of the electromagnetic
spectrum for
example, the visible region, infrared and/or ultraviolet region, when
activated by
applying a potential differejice across it or passing a current tlirough it,
for example.
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Therefore a light-emitting element can have monochromatic, quasi-monochromatic
polychromatic or broadband spectral emission characteristics. Examples of
light-
emitting elements include semiconductor, organic, or polymer/polymeric light-
emitting
diodes, optically pumped phosphor coated light emitting diodes, optically
pumped nano-
crystal light-emitting diodes or any other similar light-emitting devices as
would be
readily understood by a worker skilled in the art. Furthermore, the term light-
emitting
element is used to define the specific device that emits the radiation, for
example a LED
die, and can equally be used to define a combination of the specific device
that emits the
radiation together with a housing or package within which the specific device
or devices
are placed.
[0041] As used herein, the term "about ' refers to a +/-10% variation from the
nominal value. It is to be understood that such a variation is always included
in any
given value provided herein, whether or not it is specifically referred to.
[0042] Unless defined otherwise, all technical and scientific terms used
herein have
the same meaning as commonly understood by one of ordinary skill in the art to
which
this invention belongs.
[0043] The present invention provides an integrated self-contained lighting
module
that can be used on its own or in conjunction with other modules to produce
white light,
or light of any other colour within the available colour gamut of light
emitting elements
associated therewith. Each module comprises one or more light-emitting
elements, a
drive and control system, a feedback system, thermal management system,
optical
system, and optionally a communication system enabling comrnunication between
modules and/or other control systems. Depending on the configuration, the
lighting
module can operate autonomously or its functionality can be determined based
on both
internal signals and externa.lly received signals, solely externally received
signals or
solely internal signals.
[0044] Figure 1 illustrates a diagram of the lighting module and its
components.
The lighting module 10 includes a light source 50 comprising one or more light-
emitting
elements for generation of illumination. An external power source 40 provides
power to
the lighting module 10 wherein this provided power is regulated by the drive
and control
system 20. This power regulation can include the conversion of the supplied
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power to a desired input power level that can be determined based on
characteristics of
the light-emitting elements within the module, for example. In addition, to
power
conversion, the drive and control system provides a means for controlling the
transmission of control signals to the light-emitting elements thereby
controlling their
activation. The drive and control system can receive input data from within
the lighting
module 10, for example from the feedback system 30 and may receive external
input
data from other lighting modules or other controlling devices. An optional
communication port 100 can provide the drive and control system with the
capability for
both input and output of signals to and from the module, respectively.
[0045] The feedback system 30 within the module 10 can comprise one or more
forms of detectors or other similar devices. For example an optical sensor 70
and/or
thermal sensor 80 can be integrated into the feedback system. The optical
sensor 70 can
detect and provide information to the drive and control system that can relate
to the
luminous flux and chromaticity of the illumination generated by the light-
ernitting
elements and additionally can relate to ambient daylight readings, for
example. This
form of information can enable the drive and control system to modify the
activation of
the light-emitting elements within the module in order that a desired
illumination is
generated. A thermal sensor 80 can detect the temperature of the substrate on
which the
light-emitting elements are mounted, the temperature of one of or each of the
light=
emitting elements and the temperature within the lighting module itself, for
example.
This temperature information can be transferred to the drive and control
system thereby
enabling the modification of the activation of the light-emitting elements in
order to
reduce thermal damage of the light-emitting elements due to overheating, for
example,
thereby improving the longevity thereof.
[0046] The thermal management system 90 provides a system for transferring
heat
generated by the light source 50 to a heat sink or other heat dissipation
device. The
thermal management system comprises intimate thermal contact with the light-
emitting
elements and provides a predefined thermal path for the heat to be transferred
away from
the light-emitting elements. Optionally, the thermal management system may
further
provide a means for transferring heat away from the drive and control system.
[00471 The optical system 60 receives the illumination created by the light
source 50
and provides a means for efficient optical manipulation of this illumination.
The optical
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system can for exarnple provide a means for the collection and/or collimation
of
luminous flux 110 emitted by the light source 50 and can provide colour mixing
of the
emission of multiple light-emitting elements. The optical system can also
provide
control over the spatial distribution of light emanating from the lighting
module. In
addition, the optical system can provide a means for directing a fraction of
the
illumination to the optical sensor 70 in order to enable feedback signals to
be generated
which are representative of the characteristics of the illumination generated
by the
lighting module.
[0045] In one embodiment the drive and control system 20 of a lighting module
can
operate independently of other externai lighting modules and an external
control system.
[0049] In another embodiment, the drive and control system 20 can receive
input
data from other lighting modules or an external control system via an optional
communications port 100, wherein this data can include status signals,
lighting signals,
feedback inforn7ation and operational commands, for example. The drive and
control
system 20 can equally transmit this externally received data or internally
collected or
generated data to other lighting modules or an external control system. This
transmission of information can be enabled by the optional communication port
100
coupled to the drive and control system.
Light Source
[0050] The light source comprises one or more light-emitting elements that can
be .
selected to provide a predetermined colour of light. The number, type and
colour of the
light-emitting elements within the light source can provide a means for
achieving high
luminous efficiency, a high Colour Rendering Index (CRI), and a large colour
gamut.
The light-emitting elements can additionally be positioned with respect to the
optical
system to achieve optimal colour mixing and collimation efficiency. The light-
emitting
elements can be manufactured using either organic material, for example OLEDs
or
PLEDs or inorganic material, for example semiconductor LEDs. The light-
emitting
elements can be primary light-emitting elements that can emit colours
including blue,
green, red or any other colour. The light-emitting elements can optionally be
secondary
light-emitting elements, which convert the emission of a primary source into
one or
more monochromatic wavelengths, polychromatic wavelengths or broadband
emissions,
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for example in the cases of blue or UV pumped phosphor coated white LEDs,
photon
recycling semiconductor LEDs or nanocrystal coated LEDs. Additionally a
combination
of primary" and/or secondary light-emitting elements can be employed. As would
be
readily understood by a worker skiIled in the art, the one or more light-
emitting elements
can be mounted for example on a PCB (printed circuit board), a MCPCB (metal
core
PCB), a metallized ceramic substrate or a dielectrically coated metal
substrate that
carries traces and connection pads. The light-emitting elements can be in
unpackaged
form such as in a die format or may be packaged parts such as LED packages or
may be
packaged with other components including drive circuitry, feedback circuitry,
optics" and
control circuitry.
[0051] In one embodiment, an array of light-emitting elements having spectral
outputs centred around wavelengths corresponding to the colours red, green and
blue
can be selected, for example. Optionally, light-emitting elements of other
spectral
output can additionally be incorporated into the array, for example light-
emitting
elements radiating at the red, green, blue and amber wavelength regions may be
configured as the light source or optionally may include one or more Iight-
emitting
elements radiating at the cyan wavelength region. The selection of light-
emitting
elements for the light source can be directly related to the desired colour
gamut and/or
the desired maximum luminous flux and colour rendering index to be created by
the
lighting module.
[0052] In another embodiment of the present invention, a plurality of light-
emitting
elements are combined in an additive manner such that any combination of
monochromatic, polychromatic and/or broadband sources is possible. Such a
combination of light-emitting elements includes a combination of red, green
and blue
(RGB) light-emitting elements, red, green, blue and amber (RGBA) light-
emitting
elements and combinations of said RGB and RGBA together with white light-
emitting
elements. The combination of both primary and secondary light-emitting
elements in an
additive manner is possible. Furthermore, the combination of monochromatic
sources
vvith polychromatic and broadband sources such as light-emitting elements
generating
light having colours RGB and white, GB (green and blue) and white, A (amber)
and
white, RA (red and amber) and white, and RGBA and white is also possible. The
number, type and colour of the multiple light-emitting elements can be
selected
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depending on the lighting application and to satisfy lighting requirements in
terms of a
desired luminous efficiency and/or CRI.
f
[0053] In one embodiment, the light-emitting elements may also be selected on
the
basis of similar temperature dependencies, for example phosphor-coated white
LEDs,
green LEDs, and blue LEDs that are based on a common InGaN semiconductor
technology. This selection criteria of light-emitting elements for the light
source may
provide for ease of temperature compensation during control of these light-
emitting
elements.
[0054] In one embodiment, multiple light-emitting elements can be connected
electrically in a plurality of configurations. For example, the light-emitting
elements can
be connected in series or parallel configurations or combinations of both. In
one
embodiment of the present invention, two or more light-emitting elements are
connected
in series as linear strings, wherein a string may comprise light-emitting
elements of the
same colour bin, or a combination of colours or colour bins, for example. In
this
embodiment of the present invention, all of the light-emitting elements in a
string are
electrically connected such that they are powered as a group by the drive and
control
system of the lighting module.
[0055] In another embodixnent of the present invention, the light-emitting
elements
are grouped in series as pairs of linear strings, wherein a string may
comprise light-
emitting elements from a combination of colour bins of the same generic
colour, for
example blue, wherein the dominant wavelengths of the light-emitting elements
for one
of the pair of linear strings are equal to or greater than a predetermined
wavelength and
the dominant wavelengths of the light-emitting elements of the other string of
the pair of
strings are equal to or less than this predetermined wavelength. Therefore, by
adjusting
the relative drive currents to each string of a pair of strings of a given
colour, it can be
possible to dynamically adjust the effective dominant wavelength of that given
colour
for the light module. In this manner a plurality of lighting modules forming a
lighting
network can exhibit the same colour gamut and generate light of the same
chromaticity
in response to a command for the entire lighting network.
[0056] In another embodiment of the present invention, light-emitting elements
are
electrically connected in order that each individual light-emitting element
can bc
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individually managed and controlled by the drive and control system of the
lighting
module. For example, a string of light-emitting elements can be wired such
that some
light-emitting elements can be bypassed either partially, or completely to
allow this
individual control of each light-emitting element independent of one another.
Drive and Control System
[0057] The integrated drive and control system can accept power from an
external
power source, regulate it and distribute it to the.light-emitting elements.
The drive and
control system can provide power control in response to signals received from
the
feedback system, for example optical and thermal feedback signals in order to
maintain
110 a set colour balance and light output within predefined limits. The
performance of the
drive and control system can be configured to have a high efficiency and
smooth
response in order to maintain a stable load on the extenlal power supply,
while at the
same time enabling the rapid switching of the activation of the light-emitting
elements
and changes in power settings without creating excessive current spikes or
visible
fluctuations in the light output. In addition, the drive and control system
can be flexible
in order to accommodate different types of light-emitting elements in the
lighting
module with different forward voltages'and/or current requirements without the
need for
binning thereof, as is presently performed in the prior art.
[0058] The drive and control system provides a means to control the supply of
power to the multiple light-emitting . elements. In one embodiment of the
present -
invention, the drive and control system uses digital switching to aehieve this
form of
control. The power supplied to the light-emitting elements can be digitally
switched
using techniques such as pulse width modulation (PWM), pulse code modulation
(PCM)
or any other similar approach known in the art. In this manner the control of
the
illumination generated by each of the light-emitting elements or strings
thereof can be
controlled, enabling the creation of a desired illumination effect such as
dimming,
strobing, or other visible or invisible effects, for example optical
communication signals.
[0059] In one embodiment of the present invention, light-emitting elements
connected in series can be powered by a single external power supply, wherein
all light-
emitting elements in the series can be controlled as a unit, by the drive and
control
system.
CA 02589238 2007-05-22
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[0060] The drive and control system can be configured to activate the light-
emitting
elements at a previously determined frequency, wherein this can be an optimal
frequency. In one embodiment, the selected switching frequency may be selected
in a
manner that one or more of the following characteristics are satisfied, for
example the
switching frequency is sufficiently high in order that visual flicker is not
perceptible for
example greater than about 60 Hz, audible resonances of the power components
are-
beyond the range of human hearing for example greater than about 16 kHz, and
thermal
stressing of the light-emitting elements can be minimized by ensuring that the
selected
switching period is substantially less than the thermal time constant of for
example the
LED die, which is typically on the order of ten milliseconds resulting in a
desired
switching frequency greater than about 1 kHz.
[0061] In another embodiment of the present invention, the junction
temperature of
the light-emitting element for example an LED die, is monitored and the
maximum
slope of change in drive current is limited in order to limit the maximum
change in
junction temperature over time, thereby limiting thermal stressing of the
light-emitting
element that may otherwise lead to premature device failure due to for example
wire
debonding or accelerated device aging due to non-radiative dislocation growth.
[0062] In one embodiment of the present invention, the drive and control
system
uses a microcontroller or a field programmable gate array (FPGA). The
microcontroller
or FPGA array can receive signals from the feedback system, relating to
operational
conditions of the lighting module, for example optical feedback, temperature
feedback
and can additionally receive external control signals in order to generate the
digital
switching signals to be transmitted to each light-emitting element or string
thereof. In
this manner, the intensity levels of the light-emitting elements can be
determined based
on the received information thereby enabling the generation of a desired
colour and
intensity of illumination.
[0063] Furthermore, in one embodiment each light-emitting element or string
thereof can he connected to a high-efficiency switching converter in order to
provide
constant current output from a common voltage supply rail. This can be
configured to
provide a constant DC current, or a constant peak current in the case where
the light-
emitting elements are to be digitally switched at varying duty cycles. In this
manner,
strings having varying voltage drops across a string can be appropriately
driven using the
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same voltage supply since each string would only be provided the voltage
required to
drive it at apredetermined current level. In one embodiment of the present
invention, a
buck converter associated with a particular light-emitting element or string
thereof can
be configured to regulate the power supplied thereto depending on the voltage
drop
across the light-emitting element or string and the specific voltage supplied
by the
common voltage supply rail. As would be readily understood by a worker skilled
in the
art, any form of switch-mode DC-DC converter can be used, for example a fly-
back,
buck, boost, or buck-boost converter.
[0064] In another embodiment of the present invention the drive current
supplied to
the light-emitting elements is reduced when the lighting module is dimmed. For
example, the drive current may be 100 percent of maximum over the range of 50
percent
to 100 percent of maximum luminous flux output, and 50 percent of maximum for
luminous 11ux output less than 50 percent of the maximum value. A particular
advantage of this configuration is that the duty factor of a PWM or PCM drive
signal is
increased for low light levels. This configuration can relax the timing
requirements for
example saurpling of the luminous flux output of an optical sensor or the
forward
voltage by a voltage sensor. Another advantage is that the drive current
harmonics due
to a binary pulse wave with a small duty factor can be reduced, thereby
alleviating
potential problems with power line harmonics and radio-frequency eniissions.
[0065] In one embodiment of the present invention the drive and control system
can
be integrated with other electronics on the same printed circuit board (PCB)
which can
further include the light emitting elements; in order to provide a small form
factor
design, as illustrated in Figures 8 or 9 for example. Alternatively, the drive
and control
system can be placed on a separate dedicated PCB adjacent to a PCB that holds
the other
'electronics and light-emitting elements, with these boards being electrically
and
mechanically interconnected to achieve a different form factor, as illustrated
in Figure
12, for example. A particular advantage of this using separate dedicated PCBs
is that
the drive and control system can be thermally isolated from the heat-
generating light-
emitting elements, thereby reducing device temperatures and improving system
reliability and the environmentaf operating temperature.
[0066] In one embodiment the drive and control system can be separated into
two
separate functional blocks as shown in Figure 2 wherein the driver module 1000
accepts
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input from the control module 1005 and interfaces to the light-emitting
elements, for
example red LEDs 1010, green LEDs 1015 and blue LEDs 1020 to maintain a drive
level based upon that input. The multiple colour LEDs 1010, 1015 and 1020,
driver
module 1005, control module 1000 and sensor module 1025 can be configured as
shown
in Figure 2. The sensor module forms a portion of the feedback system 30 as
illustrated
in Figure 1. The operating characteristics of the LEDs 1010, 1015, 1020 can be
monitored by the sensor module 1025 which detects their light output,
operating
temperature, or other information, and therefore the sensor module may include
one or
more optical sensors, one or more temperature sensors, and any other requi'red
sensor
depending on the desired information to be collected.
[0067] In one embodiment, some light emitted by the LEDs 1010, 1015, 1020 may
be sent directly to the optical sensors in the sensor module 1025 without
passing through
the optics 1030. In an altemate embodiment an optical signal representative of
the
characteristics of the light generated by the LEDs may be indirectly measured
within the
optics 1030 as 'light first passes through the optics. Thus in one embodiment
of the
system which uses multiple colours of LEDs, for example red, green, and blue,
the
signal detected by the optical sensors can be representative of the mixed
light from all
the LEDs.
[0068] In the embodiment illustrated in Figure 2, the control module 1000 can
send
a signal or signals to the driver module 1005 to drive the red LEDs 1010,
green LEDs
1015 and blue LEDs 1020 to a desired level such that the combined output from
these
LEDs is maintained at a desired intensity and chromaticity set point,
wherein'this signal
or signals can be based on the one or more feedback signals from the sensor
module
1025. For example, this set point may be stored internally in the control
module, or the
set point may be adjusted based on user input via a user interface, for
example. In one
embodiment, the control module can act autonomously to maintain white light
output
from the lighting module, such that this light output lies substantially on
the black body
locus. Through the active monitoring of the mixed light output generated by
the lighting
module through the use of the feedback system, the control module can evaluate
and
send control signals to the driver module in order to maintain the desired
light output.
[0069] In one embodiment, in response to inputs from a user interface, the
control
module can be made to adjust the CCT of the white output light. In this case,
the user
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WO 2006/056066 PCT/CA2005/001792
does not have any direct control over the output of the light-emitting
elements as the
control module can perform appropriate calculations in order to actively
adjust the light-
emitting element drive current levels and hence the colour balance can be
maintained at
a desired white point. This procedure can greatly simplify adjustments of the
CCT by
the user and allow for a basic user interface, such as a wall dimmer.
[0070] In another embodiment, a user can increase or decrease the overall
light
output intensity of the lighting module while allowing the control module to
maintain
the proper ratios of intensity between the different colours of light-emitting
elements,
and hence maintain substantially the same white point even while dinuning. In
another
embodiment, the control module can be configured to maintain any point or set
of points
within the colour gamut of the light-emitting elements of the light source. In
another
embodiment, a sophisticated user interface may provide a user with the ability
to select
any of the colours in the colour gamut, wherein the control module can
maintain this
selected colour through the active data received from the feedback system.
[0071] Figures 3A to 3G illustrate how a driver module can regulate power to
the
light-emitting elements, for example LEDs. As is known, LEDs are constant
current
devices, and in one embodiment shown in Figure 3A, the driver module 2000 and
in
particular a driver 2005 or 2010 sends a drive signal to the LED or LED string
2015 or
2020 and receives a return signal back therefrom, thereby allowing for closed
loop
current control of the LEDs. In one embodiment, the drive signal and return
signal are
the drive and return currents supplied to the LEDs. Within a driver, the level
of current
supplied to the LED can be monitored to ensure that for a given control input
from the
control module, a fixed current level is maintained through the LED regardless
of
variations in forward voltage due to temperature, aging, or other degradation
effects of
the LED. In one embodiment, a driver includes a currcnt scnsc resistor in
order to allow
the drive current to be monitored. In one embodiment, as illustrated in Figure
3A, one
driver accepts one control input and drives one LED or one string of LEDs, and
multiple
drivers are used for multiple LEDs or multiple strings of LEDs. This
configuration of
the drive module can allow for example one driver to be connected to LEDs of
one
colour, in order that one control input can enable the setting of all of the
LEDs of a
single colour to the same level without affecting any other colours of LEDs or
strings of
LEDs. The driver module configuration as illustrated in Figure 3A can remain
essentially the same regardless of a difference in forward voltage
requirements between
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WO 2006/056066 PCT/CA2005/001792
different LED sirings. Alternately, as illustrated in Figure 3B, a single
driver with
multiple outputs can be used to drive multiple LEDs or multiple strings of
LEDs based
on multiple control inputs.
[0072] Figures 3C to 3G show alternate configurations of information transfer
between a driver and the LED or string of LEDs that it controls, wherein these
configurations enable closed loop current control. In Figure 3C the driver can
send a
drive signal to the LED and receive an associated return signal from the LED
and further
receive a sense signal from the LED. The sense signal can indicate for example
the
voltage across one or more of the LEDs in the string, wherein th.is can be
used to
manitor the current level. In an alternate embodiment as illustrated in Figure
3D, the
return path from the LED to the driver can be eliminated by connecting the LED
to
ground. In a further embodiment as illustrated in Figure 3E, the sense signal
can be
eliminated when a current sensing device is integrated within the driver.
Figure 3F
illustrates an embodiment, wherein the drive signal can be eliminated by
connecting the
LEDs directly to the input power supply, however this configuration requires a
return
signal for the driver to maintain the current at a desired level which can be
performed
using internal current sensing and limiting at the LEDs. In another embodiment
as
illustrated in Figure 3G a return signal and sense signal can be input into
the driver for
an instance where current sensing is not performed within the driver.
[0073] In one embodiment the control module can send digital signals to the
driver
module which is configured to switch the drive signal to the light-emitting
elements on
and off in response to the signals received from the control module, wherein
this
switching can be performed using pulse width modulation (PWM), pulse code
modulation (PCM), or other digital switching protocol, wherein the on time of
the light-
emitting elements can be varied. Since the driver module maintains a constant
current
through the light-emitting elements while they are on, the peak current
remains the same
while the average current or average power through the light-emitting elements
is varied.
Hence the intensity of the output 'light is directly proportional to the on
time or duty
cycle of the switching signal. This dinuning method can provide a means for
minimizing wavelength shift. As the peak wavelength of a light-emitting
element can
be strongly influenced by the junction temperature, the thermal management
system
associated with the lightin.g nlodule can be configured to prevent excessive
junction
temperatures from arising, even during periods when the light-emitting
elements are
CA 02589238 2007-05-22
WO 2006/056066 PCT/CA2005/001792
being driven at higher than typical current levels. Large changes in peak
current, even
for the same average power, or junction temperature, may cause noticeable
wavelength
shifts. Therefore by maintaining the same peak current while changing the
average
current can assist in ensuring that there is reduced peak wavelength shift
over the full
dimming range, thereby improving the ability of the drive and control system
to
maintain a given chromaticity.
[0074] In another embodiment the control module can send digital signals to
the
driver module, wherein the driver module is configured to convert these
digital signals
into analog drive signals for transmission to the light-emitting elements,
wherein this
conversion can be performed by a digital-to-analog converter.
[0075] In one embodiment the digital signals transmitted to the light-emitting
elements are transmitted at a desired frequency in order to eliminate visible
flicker from
the generated illumination and to ensure a desired level of resolution at low
duty cycles
which may be required to maintain control of the output intensity and
chromaticity. In
another embodiment of the system, the control module may send more than one
control
input to each driver module, wherein this secondary signal may be used to
adjust the
peak current level which the driver module sends to the light-emitting
elements thereby
providing a means to improve the resolution at low dimming levels.
[0076] In one embodiment of the present invention, the electronic components
of the
driver module and control module are mounted on a common circuit board such as
polyimide or polyester laminates. In another embodiment, the electronic
components of
the driver module and control module are mounted on separate single or
multilayer
circuit boards that are electrically and mechanically interconnected via one
or more
flexible layers. These configurations of the circuit board or boards for the
driver module
and control module electronic components may be positioned within the lighting
module
in order to provide a potentially desirable small form factor and/or to
facilitate the
dissipation of heat generated by the driver module and control module
electronic
components.
[0077] In one embodiment of the present invention, the drive and control
system 20
receives input signals from and responds to external devices via
communications port
100, whcrein these external devices may include occupancy sensors, timers,
daylight
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WO 2006/056066 PCT/CA2005/001792
sensors, infrared communications sensors, optical communications sensors,
wireless
communications modules, building management systems, Iighting network routers
and
bridges, data communications network routers and bridges, personal computers,
and user
interfaces, for example. The responses to these received input signals may
include
scheduled lighting control sequences, on/off and dinuning and control and/or
colour
changing, occupancy sensor responses, load shedding, daylight harvesting,
emergency
lighting responses, status and fault reporting, and system and/or component
lifetime
information reporting.
[0078] In another embodiment of the present invention, the maximum drive
current
supplied to the light-emitting elements is initially less than the
manufacturer's rated
maximum current. The maximum drive current is then slowly increased over the
lifetime
of the light-emitting elements (which may be on the order of tens of thousands
of hours)
so as to compensate for device aging and consequent lamp lumen depreciation,
until the
maximum drive current is equal to the manufacturer's rated drive current at
the
estimated end-of-life of the light-emitting elements.
[0079] In one embodiment of the present invention, as the lighting module
comprises a thermal management system the drive and control system can be
configured
to operate the light-emitting eleinents beyond a manufacturer's maximum rated
current,
for example the light-emitting elements can be overdriven, in order to
increase the
luminous flux output of the lighting module, when required. The thermal
management
system provides a means for effectively transferring heat away from the light-
emitting
elements, thereby providing a means the light-emitting elements to be
overdriven
without reducing the longevity or operational characteristics of the light-
emitting
elements due to thermal considerations.
Feedback System
[0080] The lighting module further comprises a feedback system for collecting
and
forwarding operational characteristics of the lighting module to the drive and
control
system, thereby enabling modification of the operational characteristics to
meet
predetermined criteria. The operational characteristics can include lighting
or
illumination characteristics, thermal characteristics, and/or other
characteristics as
required. The feedback system within the lighting module can comprisc one or
more
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forms of detectors or other feedback-type devices. For example, an optical
sensor and/or
thermal sensor can be integrated into the feedback system. The optical sensor
can detect
and provide information to the drive and control system that relates to the
radiant flux
and chromaticity of the light-emitting elements in addition to ambient
daylight readings,
for example. This information can enable the drive,and control system'to
modify the
activation of the light-emitting elements within the lighting module in order
that a
desired illumination is generated. For example, this form of feedback can
enable the
lighting module to maintain a desired illumination level and colour, and may
further
'enable compensation for ambient light conditions. The feedback system can be'
configured to enable the drive and control system to react with sufficient
speed and
stability in order that changes in the light level or colour cannot be
detected visually by
an observer. In one embodiment, the feedback system can operate at a sampling
frequency of greater than or equal to about 250 Hz.
[0081J Feedback can also be provided by thermal sensors that detect the
temperature
of the substrate or circuit board on which the light-emitting elements are
mounted, the
temperature of one or more of the light-emitting elements, and the temperature
within
the lighting module itself, for example. This information can be transferred
to the drive
and control system, thereby enabling the modification of the activation of the
light-
emitting elements in order to prevent thermal damage of the light-emitting
elements due
to overheating, for example thereby improving the longevity thereof.
Furthermore,
through the monitoring of temperature, control of the operation of the
lighting module
can be performed in a manner that results in temperature-insensitive operation
such that
the desired illumination level and colour are maintained within predefined
limits
regardless of the temperature, wherein this temperature can be the ambient
temperature
or a temperature measured within the lighting module.
[0082] In one embodiment of the present invention, a thermal sensor is
configured to
monitor the temperature of the one or more optical sensors. In this manner the
variations in the light detection characteristics of the one or more optical
sensors due to
temperature variations can be compensated for by the drive and control system.
This
compensation of the optical sensors temperature dependence may provide a means
for
the lighting module to generate and maintain desired illumination
characteristics in an
effective and efficient manner.
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[0083] The feedback system can comprise one or more sensors with the required
circuitry, wherein the collected information is subsequently transmitted to
the drive and
control system. In one embodiment, one or more optical sensors are positioned
geometrically in order to optimize the reception of adequate illumination for
appropriate
operation of the optical sensor. Furthermore the one or more optical sensors
can be
interfaced with appropriate circuitry in order to condition and/or amplify the
signals
generated by the optical sensors, as required. The circuitry interfaced with
the one or
more optical sensors can additionally provide a means for providing one or
both of
signal gain control and modification of an integration time constant.
[0084] In one embodiment and having particular regard to the collection of
optical
characteristics of the light generated by the light source, the light-emitting
elements
forming the light source are grouped into two or more clusters of one or. more
light-
emitting elements with the clusters arranged such that a portion of the light
emitted from
each cluster is directly incident upon a central axis, wherein every point
along the central
axis is equidistant from each cluster. The light-emitting elements within each
cluster are
typically placed close to each other relative to the distance between each
eluster. The
path length of the light from each light-emitting element incident on each
point along
the central axis is thus approximately equal for all the light-emitting
elements. One or
more optical sensors also having a central axis associated thercwith are
positioned such
that the central axis of the clusters and the central axis of the optical
sensor coincide. In
this manner a substantially equal optical path length from each cluster to the
optical
sensor is provided and can ensure that substantially an equal portion of light
from each
cluster is incident upon the optical sensor.
[0085] In one embodiment of the present invention, the feedback system
comprises a
plurality of filtered optical sensors with associated colour filters, for
example silicon
photodiodes with dyed plastic filters, to measure the chromaticity and
intensity of the
illumination generated by the lighting module. Thin-fihn interference filters
and
polymer optical interference filters based on giant birefringent optics (GBO)
as
described for example by R. Strharsky and J. Wheatley in "Polymer Optical
Interference
Filters," Optics & Photonics New, Nov. 2002, pp.34 - 40, may also be used, as
may
planar dielectric waveguide gratings as described for example by R. Magnusson
and S.
Wang, 1992, "New Principles for Optical Filters," Applied Physics Letters
61(9): 1002-
1024 and S. Peng and G. M. Morris, 1996, "Experimcntal Demonstration of
Resonant
24
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Anomalies in Dif&action from Two-Dimensional Gratings," Optics Letters
21(8):549-
551. Each colour filter can for example exhibit spectral bandpass
characteristics that
limit the response of an optical sensor to a predetermined range of
wavelengths of
visible light, such as for example red, green, and blue. In a further
embodiment, the
temperature of the filtered optical sensors is monitored so that possible
temperature-
dependent changes in the optical filter spectral absorption characteristics
(such as is
known to occur with thin-film interference filters) can be estimated. This
thermal
monitoring of the optical sensor can enable comperisation of the temperature
dependence thereof. Appropriate circuitry can also be incorporated in the
optical sensor
in order to filter out any unwanted noise and additionally provide
amplification of
optical sensor signals as required.
[0086] In one embodiment of the present invention, a single optical sensor is
used to
monitor each of the light-emitting elements individually for their
contribution to the
total light output of the lighting module. In this embodiment, a polling
sequence can'be
used in order to collect illumination contributions of each of the light-
emitting elements
individually, through for example sequential activation of each light-emitting
element
individually.
[0087] In another embodiment of the present invention, a plurality of optical
sensors
is used to monitor a single light-emitting element or group thereof.
[0088] In one embodiment of the present invention, a light-emitting element,
when
in a deactivated state can be used to measure the intensity and chromaticity
of the light
incident thereupon thereby providing another means for illumination detection.
[0089] In another embodirnent an optical sensor can comprise a linear array of
light
detectors that act as a spectroradiometer, thereby enabling a more complete
25. representation of the illumination. This optical sensor can provide a
means for the drive
and control system to more accurately control the light-emitting elements, as
it provides
both intensity and chromaticity information.
[0090] In one embodiment the temperature sensor is a thermistor, thermocouple,
semiconductor diode, or transistor with a known temperature dependency curve,
thereby
enabling collection of a temperature feedback sxgnal. In addition, temperature
feedback
relating to the operation of the lighting module can be derived from the
forward voltage
CA 02589238 2007-05-22
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of the one or more light-emitting elements or other known parameters that vary
with
temperature, for example the peak wavelength of a light-emitting element.
[0091] In one embodiment of the present invention, the feedback system
comprises a
proportional-integral-derivative (PID) controller to accept sensor inputs and
provide
feedback signals to the drive and ,control system in such a manner as to
maintain
constant luminous flux output and chromaticity, and to minimize visually
perceptible
undershoot or overshoot of luminous flux output and chromaticity in response
to
changes in the feedback signals.
[0092] In another embodiment of the present invention, the feedback system
includes a trainable neural network such as is described in United States
Patent
Application Publication No. 2005/0062446, "Control System for an Illumination
Device
Incorporating Discrete Light Sources," to linearize the feedback sensor
signals prior to
their input to the PID controller. In this embodiment the feedback system
comprises a
computing means for receiving. the information from one or more sensors and
determining control parameters based on a multivariate function having a
solution
defining the hyperplane representing constant luminous intensity and
chromaticity.
Under these conditions the computing means can essentially linearise the
information
from the one or more sensors, thereby determining a number of control
parameters from
the input information, for transmission to the drive and control system. The
drive and
control system can subsequently determine the control signals to be sent to
the light-
emitting elements in order to control the illumination produced thereby.
Thermal Management System
[0093] The lighting module further comprises a thermal management system for
the
removal of heat,generated by the light-emitting elements. The thermal
management
system comprises intimate themial contact with the light-emitting elements and
provides
a predefined thermal path for the heat to be transferred away from the light-
emitting
elements. The thermal path has a low thermal resistance along the transference
pathways
and contacts between these pathways and the Iight-emitting elements.
Passive Coolina
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[0094] In one embodiment of the present invention, the thermal management
system
comprises one or more heat pipes. A heat pipe has a condenser end and an
evaporator
end, wherein the condenser end may attach to a heat sink, or other heat
removal or
dissipation device, which enables the transfer of heat to a medium extemal to
the
lighting module. The evaporator end is in thermal contact with the light-
emitting
elements. The light-emitting elements can be in direct physical contact with
the
evaporator end of the heat pipe or may optionally be mounted on a thermally
conductive
substrate, for exatnple a metal core printed circuit board (MCPCB) or a
thermally
conductive substrate with conductive metallic traces applied thereupon,
wherein the
substrate is in direct contact with the evaporator end of the heat pipe. The
working fluid
associated with the heat pipe, wherein the working fluid transfers the heat
from the
evaporator end to the condenser end of the heat pipe, can be selected from a
variety of
fluids including water and other suitable liquids, for example, as would be
readily
understood. In addition, the one or more heat pipes can be designed with a
specific
shape, length and working fluid for a.desired application of the lighting
module.
[0095] In one embodiment, one or more heat sinks are thermally connected to
the
one or more heat pipes along their length.
[0096] Figure 19 illustrates one embodiment of the thermal management system
wherein the heat pipes 1028 are thermally connected to a heat sink 1029
comprising a
plurality of fins which are positioned in an angled orientation relative to
the length of the
heat pipes. The angle of the connection between the fins and the heat pipe may
provide
a means for improvement of the movement of air though the heat sink relative
to fins
mounted perpendicular to the longitudinal direction of the heat pipes.
[0097] In one embodiment the thermal resistance of the contact location
between a
heat pipe evaporator end and the substrate can be minimised using a thermally
conductive material such as thermal grease, solder or thermally-conductive
epoxy.
Furthermore, the evaporator end of the heat pipe can be shaped, polished or
machined to
increase the contact area between the heat pipe and the substrate, thereby
improving
thermal conductivity there between. In addition, the substrate on which the
light-
cmitting elements are mounted can be constructed of a thin, highly thermally
conductive
material, for example chemical vapour deposition (CVD) diamond, aluminium
nitride
ceramic, beryllium oxide ceramic, alumina ceramic, copper and polyimide,
silicon or
27
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silicon carbide. The attachment of the light-emitting elements to the
substrate can be.
made in a manner so as to substantially maximise thermal conductivity
therebetween. In
this embodiment, the evaporator of the heat pipe can be integrated into the
substrate,
submount or package upon which the light-emitting elements are mounted.
[0098] In another embodiment of the present invention, the thermal management
system comprises a thermosyphon device. A thermosyphon transfers heat away
from the
light-emitting elements using an evaporator/condenser scheme similar to a heat
pipe as
previously described, but wherein the evaporator and condenser are connected
by a
continuous loop for fluid and vapour flow. In this embodiment the evaporator
of the
thermosyphon can be integrated into the substrate upon which the light-
emitting
elements are mounted.
Active Cool
[0099] In one embodiment of the present invention, the thermal management
system
comprises a Peltier-effect thermoelectric cooling device or thermotunneling
cooling
device as disclosed in for example U.S. Patent No. 6,876,123 that can be
attached to, or
integrated into, the substrate upon which the light-emitting elements are
mounted. A
thermoelectric device is a solid-state device that, upon application of an
electric bias,
would enable heat transfer from the light-emitting elements to a thermal
pathway that
can be defined by a heat pipe or thermosyphon, for example. In this
embodiment, a heat
pipe or thermosyphon can be thermally connected to the hot side of the
thermoelectric or
thermotunneling device.
[00100] In another embodiment the thermal management system includes a
thermionic device as described for example in A. Shakouri and J. E. Bowers,
1997,
"Heterostructure Integrated Thermionic Coolers," Applied Physics Letters
71(9):1234-
1236, which is attached to, or integrated into, the substrate upon which the
light-emitting
elements are mounted. In a thermionic device, the application of an electric
bias can
provide a means for heat to flow away from one surface, for example the
substrate.
[00101] In another embodiment the thermal management system comprises a fluid
cooling system, for example water or cooling oil, that is pumped through a
heat
exchanger that is attached to, or integrated into, the substrate upon which
the light-
emitting elements are mounted. The fluid can act as a thermal pathway and
transfer heat
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to another heat exchanger, for subsequent transfer to an external medium, for
example
ambient air. Alternatively, the fluid can be pumped over any or all of the
surfaces of the
light-emitting elements using a mechanical pump or a microfluidic pump.
[00102] In one embodiment of the present invention, the external medium to
which
heat is transferred by the thermal management system is a fluid readily
available to the
lighting module. For example in some configurations, an air-conditioning
system or a
water system may be proximate to the lighting module and therefore the thermal
management system can be configured to enable transfer of the heat to this
external
system, as an alternative to ambient air.
[00103] In another embodiment the thermal management.system comprises a fan or
other mechanical device for enabling airflow in order to enhance thermal
transfer and
dissipatioii.
Optfcal,System
[00104] The optical system provides a means for efficient light extraction and
efficient optical manipulation of the emissian of the light source. The
optical system
can provide a means for the extraction and collection of radiation,
collimation of the
emission and mixing of the spectral content of the emission from multiple
light-emitting
elements, for example. The optical system can also provide control over the
spatial
distribution of light emanating from the lighting module. In addition, the
optical system'
can provide a means for directing a fraction of the emission to an optical
sensor and may
additionally block ambient light from the optical sensor in order to enable
generation of
feedback relating to the lighting module's output illumination
characteristics.
[00105] The optical system can be designed to provide characteristics
including any
one or more of optimal collection efficiency of the illumination emitted by
thc light
source, minimal losses in the optics, beam collimation with low residual
divergence or a
closely-matched Lambertian beam profile, optimal colour mixing within a short
optical
path length, and geometrically-controllable luminous distribution without
undesired
spatial luminous intensity or chromaticity variations.
100106] The optical system can use a variety of optical elements to produce a
desired
luminous intensity and ehromaticity distribution. The optical elements can
include one
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or more of refractive elements, for example glass or plastic lenses, compound
parabolic
concentrators (CPC) or advanced modifications thereof such as tailored
dielectric total
internal reflection optics, Fresnel lenses, GRIN lenses and microlens arrays.
The optical
elements can also include reflective and diffractive elements, including
holographic
diffusers and GBO-based mirrors.
[00107] In one embodiment the lighting module can comprise a set of
submodules.
In this configuration the optical system can be divided into primary optics to
collect and
manipulate the emission of the light-emitting elements of a submodule and
secondary
optics to manipulate the output of each submodule and thereby further shape
the output
of the lighting module. Optionally, secondary optics may not be required if
the primary
optics provide desired manipulation of the emitted luminous flux. Providing
primary
and secondary optical elements can enable multiple manipulation stages of the
illumination generated by the light-emitting elements of the lighting module,
thereby
enabling the creation of a desired illumination pattern. In one embodiment the
primary
optics are configured to perform light extraction and collimation and the
secondary
optics are configured to perform light mixing. It would be readily understood
that the
primary and secondary optics can perform any desired manipulation of the light
generated by the light source.
1001081 In one embodiment light-emitting elements of RGB or RGBA or white or
a'
combination of white and colour light-emitting elements are closely packed and
encapsulated in encapsulation material that enhances light extraction. An
optic to,
enhance the light extraction, such as a dome lens can be placed in close
proximity to the
light-emitting elements. A reflective optic such as a tapered hollow light
pipe can
collimate and mix the light emission. It is understood that the optic can take
different
sectional shapes such as a parabola or a collcction of tailored multi
segmented straight
lines. Optionally a final optic such as a convex glass lens, Fresnel lens or a
more
complex lens can aid in shaping the beam output of such a submodule. A
secondary
optic such as a holographic diffuser can be placed over the submodule to
modify the
luminous distribution of the single submodule or an arrangement of multiple
submodules.
[00109] In one embodiment of the present invention, a dielectric total
internal
reflection concentrator (DTIRC) such as a CPC optical element can be used to
collect
CA 02589238 2007-05-22
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the emission from a multiplicity of light-emitting elements. As an example, a
square
array of four light-emitting elements can foxm the light source for the
lighting module or
submodule, and the optical system can be a segmented CPC arranged in a
cloverleaf
pattern in order to achieve a desired collection efficiency. Figure 4
illustrates a cross
section of a segmented CPC optic element 140 in proximity of two light-
emitting
elements 142. It is readily understood that the sectional shape of the
concentrator is not
limited to parabolic, but can also take the shape for example of a hyperbola,
ellipse,
trumpet, or a connection of many line segments wherein each segment is
designed to
meet the optical purpose desired.
1001101 In a set of embodiments of the present invention, the optical system
comprises a structure having multiple partially reflective surfaces used to
redirect,
colour mix and if required collimate the emission of a plurality of light-
emitting
elements, for example a RGBA configuration of light-emitting elements. Figure
5
illustrates a sectional view of a two dimensional arrangement of light-
emitting elements
wherein a parabolic reflector 150 is positioned proximate to the light-
emitting elements
152. Figure 6 illustrates a segmented parabolic reflector comprising three
segments 154,
156 and 158 positioned proximate to the light-emitting elements 152, also in a
sectional
view of a two dimensional arrangement. Figure 7 shows a microlens array 162
and
dichroic reflector/filter assembly 160 that can provide collimation of the
emissions from
the light-emitting elements 164. The reflective surfaces illustrated in Figure
7 are flat
however they can be any shape required, for example the reflective surfaces
can
optionally be parabolic or elliptical. These reflective surfaces can be
selectively
transmissive, for example they can be transniissive to the illumination
entering the rear
of the reflector, but reflective to the illumination generated by the light-
emitting
elements they face.
[001111 In one embodiment, an optical element of the optical system can have
the
shape.of a cup or half cup for example. This form of configuration can be-
envisioned by
rotating the 2 dimensional section views illustrated in Figures 5, 6 or 7
around an axis
parallel and in proximity to the location of the light-emitting elements. For
example this
rotation around a defined axis would be 360 for a cup shaped optical element
and 180
for a half cup shaped optical element, In an'alternate embodiment, an optical
element
can have the shape of a cone or half cone by rotating the 2 dimensional
sectional views
illustrated in Figures 5, 6 and 7 around an axis parallel and distant to the
light-emitting
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elements, by 3600 and 180 , respectively. In another embodiment, the optical
element
can take the shape of a linear optical element having a cross sectional view
as illustrated
in Figures 5, 6 and 7. Other forms of optical elements would be readily
understood by a
worker skilled in the art.
[00112] In another embodiment, the optical system comprises a plurality of
microlenses or an array of microlenses that are designed to either redirect
the emissions
of the light-emitting elements or a subset thereof to a common point, or
optionally create
a collimated illumination output.
[00113] In another embodiment the optical system comprises a diffractive
optical
element (DOE) that is used as a primary optic to create a desired luminous
intensity
distribution from the light-emitting elements. The DOE employs diffraction to
alter the
path of light incident thereupon, and can be combined with fiuther optics to
manipulate
the luminous distribution generated by the lighting module.
[00114] In another embodiment, the optical system comprises a photonic crystal
structure such -as is described in for example S. Fan, P. R. Villeneuve, J. D.
Joannopoulos, and E. F. Schubert, 1997, "Photonic Crystal Light Emitting
Diodes,"
SPIE Vol. 3002, pp. 67-73, and which when directly placed or deposited onto
the light-
emitting element that can be designed to enhance the emission of the light-
emitting
element by reducing the level of total internal retlection within the light-
emitting
element, and which may fitrther manipulate the luminous intensity distribution
of the
light-eniitting element.
[00115] In another embodiment of the present invention, the optical system can
comp.rise secondary optics wherein the secondary optics can be a DOE used to
further
modify the luminous intensity distribution. Furthermore the secondary optics
can
optionally be randomly oriented diffractive multigrating structures that
exhibit
iridescence over wide viewing angles, as described for example by T.-H. Wong,
M. C.
Gupta, B. Robins, and T. L. Levendusky, 2003, "Colour Generation in Butterfly
Wings
and Fabrication of Such Structures," Optics Letters 28(23):2342-2344..
[00116] In a further embodiment the optical system comprises secondary optics
which include - one, multiple or a combination of reflective optical elements
and/or
refractive optical elements and/or diffractive optical elements. For example,
reflective
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optical elements can include parabolic reflectors or elliptical reflectors.
Refractive
optical elements can include Fresnel lenses, regular plano-convex, biconvex,
concave-
convex lenses and diffractive optical elements can include holographic and
kinofonn
diffusers, for example.
[001171 In a furthcr embodiment of the present invention, an optical element
of the
optical system can be designed to enable the geometrical luminous distribution
of the
lighting module to be dynamically controlled by the drive and control system
or an
external operator. Optical properties of the optical. system can be changeable
in a
number of ways. The light-emitting elements can be combined with fluid lenses
such as
are disolosed in for example US Patent 2,062,468, featuring electrostatically
adjustable
focus capabilities, or liquid crystal Ienses. The application of an electric
field upon the
fluid lens causes the curvature of the lens to change and in turn alters the
focal lcngth.
Upon application of an inhomogeneous electrical field on the liquid crystal
material, a
gradient index profile can be created which in turn enables an alteration of
the focal
length of the controllable optical system. Optionally, the optical system can
comprise a
means for mechanically adjusting the one or more optical elements therein,
thereby
providing a means for dynamic alteration of the level of manipulation of the
illumination
performed by the optical system.
[00118] In one embodiment of the present invention, a function of the optical
system
is to provide a sampling of the illumination generated by the light-emitting
elements to
an optical sensor or array thereof, in order for emission characteristics to
be fed back to
the drive and control system. In one embodiment the optical system comprises
an
optical element to reflect or transmit a portion of the illumination emitted
by the light-
emitting elements onto an optical sensor or array of optical sensors. This
optical
element can optionally be coupled to a form of light guide enabling the
guiding of the
illumination to the optical sensors.
[00119] In one embodiment a rod-like structure is mounted on top of a sensor
or
sensors providing optical feedback of the luminous intensity and spectral
distribution of
the illumination. The surface of the rod can be patterned to preferentially
admit
illumination from proximate light-emitting elements and absorb or reflect
illumination
from other directions. Illumination admitted to the interior of the rod-like
structure can
be preferentially conducted towards the optical sensor or sensors. In another
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WO 2006/056066 PCT/CA2005/001792
embodiment, the rod-like structure can be connected to or be part of a final
optic or
window associated with the optical system. In this configuration the rod
provides a
means for funnelling by means of total internal reflection or Fresnel
reflections, some of
the emissions that are trapped in the optic to an optical sensor or sensor
array. In
another embodiment one or more optical elements can be designed to leak a
desired
amount of eniission of the light-emitting elements from one or more predefined
locations. The predefmed locations can be selected in order that the leaked
emissions
are either directly incident to an optical sensor or sensor array or are
selected such that
the leaked emissions of each submodule are guided through a hollow or solid
light guide
onto the optical sensor or sensor array. Such a light guide can include a
mixing chamber
in which contributions from. all submodules are mixed.
[00120] In one embodiment of the present invention, the optical system is
designed so
as to diffuse the direct view of the light-emitting elements such that their
luminances are
within the industry-standard thresholds established for eye safety.
Communication System
[00121] In one embodiment of the present invention the lighting module
comprises a
communication module that provides a means for the drive and control system to
communicate with a network of other said lighting modules and other
controlling
devices external to the lighting module. The communications system can enable
the
lighting module to interface to a network and can enable data transfer using a
range of
prior art data transmission media and data transfer protocols as would be
known to one
skilled in the art. Such data transmission media.can be for example, Ethernet,
fibre
optic, wireless, or infrared communication systems. Examples of suitable
protocols,
depending on communications needs, include analog 0-10 VDC, Digital
Addressable
Lighting Interface (DALI), ESTA protocols including D11rIX512A, RDM, and ACN,
IEEE 802.11 wireless protocols including Bluctooth and Zigbee, infrared
protocols
including IrDA and Ultra F'ast Infrared (UFIR), or any other protocol as would
be readily
understood.
[00122) The communication system can provide a means for the operation of the
lighting module in an integrated manner amongst an array of other such
lighting
modules. Each lighting module can have a communication system and associated
data
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transfer, capability and can be further integrated into a communications
network
connecting the array of lighting modules. For example the transfer of data
related to
radiant flux of the light-emitting elements, daylight and/or ambient colour
temperature,
lighting module and board temperature thereby enabling the array of lighting
modules to
operate in a unified manner.
[001231 In one embodiment of the invention the communication system c.sn
enable
the drive and control system to transmit or receive data via one or a
plurality of physical
communication formats including hardware serial or parallel bus, fibre optic
receiver or
transceiver, wireless receiver or transceiver, infrared receiver or
transmitter, or visible
light receiver. The network topology can be selected from bus, star, token
ring, mesh, or
wireless for example. Alternate network topologies would be readily understood
by a
worker skilled in the art.
[00124] In one embodiment of the present invention, the communication system
enables a network physical layer selected from those including hardwired,
fibre optic,
wireless, infrared or visible light for example. In another embodiment the
communication system enables a network comprising visible light transmitters
and
receivers wherein the transmitters are light-emitting elements and wherein the
luminous
flux output of light-emitting elements is modulated with serial data.
[001251 In one embodiment of the present invention other controlling devices
external to the lighting module may include occupancy sensors, daylight
sensors, timers,
other lighting networks, and building management systems.
[00126] The invention will now be described with reference to specific
examples. It
will be understood that the following examples are intended to describe
embodiments of
the invention and are not intended to limit the invention in any way.
EXAMPLES
EXAMPLE 1:
1001271 Figure 8 illustrates a first example of the present invention
integrated into a
multi-lighting module quad flat pack (QFP) package. The lighting unit
comprises a
CA 02589238 2007-05-22
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plurality of light-emitting elements 300 which also includes proximate optical
elements.
The reflector optic 310 manipulates the emissions from the light-emitting
elements in a
desired direction that may subsequently interact with a secondary optic 320,
if this
sceondary optical is provided. In one embodiment this secondary optic can be a
snap-on
type optic thereby enabling ease of removal and inclusion of this optic. The
light-
emitting elements can be mounted on a CVD diamond substrate 370 through the
use of a
thermally conductive adhesive thereby enabling thermal conductivity there
through. In
direct thermal contact to the CVD diamond substrate is a heat pipe 360 which
can be
held in a desired position by a housing 350. The heat pipe(s) can enable
transfer of heat
generated by the light-emitting elements away therefrom. P'urthermore the
lighting unit
comprises a substrate 340 which for example can be manufactured from FR4,
which is a
woven glass reinforced epoxy resin or alternately a MCPCB if desired. Upon the
substrate 340 can be mounted electronic components 330 including a controller,
feedback system and other desired electronic devices. Traces on the substrate
340 can
provide a means for the interconnection between the light emitting elements
and the
controller or other electrical devices as would be required, for example. In
this exannple,
a sensor that forms a portion of the feedback system can be mounted within
close
proximity of the light-emitting elements, for example proximate to one or more
light-
emitting elements within each reflector optic. Optionally a sensor can be
positioned on
the substrate 340 wherein the optical system can provides a means for
directing a portion
of the emission from the light-emitting elements thereto.
EXAMPLE 2:
[00128] Figure 9 illustrates a second example of the present invention formed
as a
modular lighting unit torchiere. The light-emitting elements 210 are mounted
on a
thermally conductive substrate 290 that is also thermally bonded to a heat
pipe 220,
thereby enabling heat transfer from the light-emitting elements to the heat
pipe for
subsequent dissipation. The ends of the heat pipe are in contact with the
housing 250
which may comprise slits 280 therein enabling the flow of air within the
housing thereby
providing an additional means for heat dissipation. Positioned below and in
operative
contact with the light-emitting elements in a PC board 240 including a drive
and control
system mounted thereon, wherein this PC board can be operatively connected to
a power
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WO 2006/056066 PCT/CA2005/001792
supply 260, for example. Furthermore the emissions from the light-emitting
elements
can be manipulated by an optical diffuser 230.
EXAMPLE 3:
[00129] Figure 10 illustrates a third example of the present invention formed
as a
modular lighting unit luminaire wherein the light-emitting elements 420 are
mounted on
a substrate or a heat pipe 410 or optionally the light-emitting elements can
be directly
mounted to the sidewall of the heat pipe. Positioned below the heat pipe and
operatively
connected to the light-emitting elements is a control board 430. A
diffuser/reflector 400
is provided to enable manipulation of the emissions of the light-emitting
elements.
EXAMPLE 4:
[00130] Figure 11 illustrates a lighting unit that comprises multiple sub-
modules
interconnected together. Each sub-module comprises light-emitting elements
520, an
optical element 540 and a heat pipe 530 in intimate thermal contact with the
light-
emitting elements. The sub-modules can be coupled together by a PC board upon
which
other electronic components 500 and 510 that can include electronic devices
providing
drive, control and feedback to one or more of the sub-modules, can be mounted.
For
example, each sub-module can comprise one or more light-emitting elements that
can
enable the creation of white light. The light-emitting elements can include
monochromatic, polychromatic or broadband wavelength emission light-emitting
elements or a combination thereof. In addition the light-emitting elements can
include
primary or secondary light-emitting elements, wherein secondary light-emitting
elements
can be phosphor-coatcd LEDs or quantum dot LEDs.
EXAMPLE 5:
[00131] Figure 12 illustrates cross section of a lighting unit wherein the
lighting and
electronic components are designed in a stacked formation. Within the housing
630 of
the lighting unit is positioned, in a stacked configuration, the power supply,
drive,
feedback, control and other required electronics on the PC boards 640, 650 and
660.
There may optionally be a fewer or greater number of PC boards depending on
the
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required electronics. These PC boards can be in thermal contact with one or
more heat
pipes 670, which can provide a means for transferring heat frorn the PC boards
to a heat
sink 680 or other heat dissipation system, for cxample. In this manner the PC
boards
may be more closely positioned due to the thermal regulation provided by the
heat pipe
or other thermal management system, thereby enabling a smaller lighting unit
to be
manufactured. The heat pipe additionally is in intimate thermal contact with
one or
more light-emitting elements 620 that can enable the removal of heat created
thereby. In
addition the emissions of the light-emitting elements can be manipulated by an
optical
element 600 positioned proximate to the light-emitting elements. A light
and/or thermal
sensor 610 can be positioned proximate to the light-emitting elements thereby
enabling
the collection of information relating to the chromaticity of the emissions in
addition to
the junction temperatures of the light-emitting elements. The lighting-
emitting elements
and the one or more sensors can be mounted on a FR4 board or MCPCB for
example.
The PC boards, the light-emitting elements and the one or more sensors are
operatively
connected to 'each other in a manner that provides each of these elements
their desired
fiznctionality.
EXAMPLE 6:
[001321 Figure 13 is a photograph of a lighting module according to one
embodiment
of the present invention. The light-emitting elements and optics are formed
into clusters
730 wherein these clusters are thermally connected to one or more heat pipes
700. The
heat transferred by the heat pipes is dissipated using multiple heat sinks 710
formed as
finned heat sinks in order to enhance heat dissipation. An optical feedback
system 740
is positioned relative to the multiple clusters in such a manner as to provide
optical
characteristics of the illumination generated by the multiple light-emitting
elements.
Required electronic components for the operation of the light module are
mounted on a
plurality of PCB boards 720. These required electronic components includes the
drive
and control system.
EXAIVIPLE 7:
[00133] Figure 14 is a lighting module according to another embodiment of the
present irivention. This embodiment of the lighting module is configured
similar to that
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illustrated in Figure 13, wherein the light-emitting eterrxents and optical
system 850 are
formed as clusters wherein these light-emitting elements these clusters are
thermally
connected to a plurality of heat pipes 800. The heat pipes pass through the
PCB boards
in order to make thermal contact with the clusters of light-emitting elements.
The heat
transferred by the heat pipes is dissipated using multiple heat sinks 810
which are
designed in the form of sleeves. A heat sink sleeve surrounds the perimeter of
a heat
pipe wherein thermal contact thercbetween can be enhanced using a thermal
grease or
other material. The heat sink sleeve can have fins along its length in order
to enhance
heat dissipation thereby. An optical feedback system 840 is positioned
relative to the
multiple clusters of light-emitting elements in such a manner as to provide
optical
characteristics of the illumination generated by the multiple light-emitting
elements.
Required electronic components for operation of the light module are mounted
on PCB
board 825 and the light-emitting elements together with the sensor system are
mounted
on PCB board 820. In one embodiment, wherein the drive and control system is
formed
for a control module and a drive module, the drive module and controller
module can be
mounted on different PCBs. For example, the control module can be mounted on
PCB
board 820 and the driver module can be mounted on PCB board 825. The
[00134] Figure 15 illustrates the embodiment of Figure 14, wherein the optical
system
850 has been separated from the light module thereby exposing the groups of
light-
cmitting elements 860 mounted on PCB board 820.
[00135] The embodiments of the invention being thus described, it will be
obvious
that the same may be varied in many ways. Such variations are not to be
regarded as a
departure from the spirit and scope of the invention, and all such
modifications as would
be obvious to one skilled in the art are intended to be included within the
scope of the
following claims.
EXAMPLE 8:
[00136] Figure 16 illustrates a lighting module according to one embodiment of
the
present invention as it may be mounted within a shaped housing 1001. The
optical
system comprises a quadertiary optic 1002, a tertiary optic 1003 for
collimating the
light, a secondary optic 1004 configured as a conical pipe for mixing the
light, wherein
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the primary optic is positioned proximate to the light-emitting elements and
the primary
optic is configured to enhance light extraction from the light-emitting
elements.
i00137) The substrate upon which the light-emitting elements are mourited is
designed to be highly thermally conductive and configured to interface with
the heat
pipe 1008 to provide a means for efficient heat transfer away from the light-
emitting
elements. The heat pipes are thermally connected to a heat sink 1009 which
provides a
means for dissipation of the heat to the environment, for example the ambient
air.
1001381 The LED PCB 1006 has mounted thereon the control module, one or more
sensors and communication system which are all configured for communication
with the
light-emitting elements. In addition the driver PCB 1007 has mounted thereon
the drive
module which is in operation communication with the control module.
EXAMPLE 9:
[00139] Figure 17 illustrates a lighting module according to one embodiment of
the
present invention. The optical system comprises a tertiary optic 1013 for
collimating the
light, a secondary optic 1014 configured as a hexagonal tapered pipe for
mixing the
light, wherein the primary optic is positioned proximate to the light-emitting
elements
and the primary optic is configured to enhance light extraction from the light-
emitting
elements.
[001401 The substrate upon which the light-emitting clements are mounted is
designed to be highly thermalty conductive and configured to interface with
the heat
pipe 1018 to provide a means for efficient heat transfer away from the light-
emitting
elements. The heat pipes are thermally connected to a heat sink 1019 which
provides a
means for dissipation of the heat to the environment, for example the ambient
air.
[00141] The LED PCB 1016 has mounted thereon the control module, one or more
sensors and communication system which are all configured for communication
with the
light-emitting elements. The substrate upon which the light-emitting elements
are
mounted is inferiorly mounted to the LED PCB, wherein a hole is located at the
location
of the light-emitting elements. In addition the driver PCB 1017 has mounted
thereon the
drive module which is in operation communication with the control module.
CA 02589238 2007-05-22
WO 2006/056066 PCT/CA2005/001792
[00142] A mounting pin 1010 can be mechanically connected to the lighting
module
and can provide a means for mechanical connection between the lighting module
and a
housing.
EXAMPLE 10:
[00143] Figure 18 illustrates an optical system according to one embodiment of
the
present invention. The optical system comprises a secondary optic 1030
configured as a
concial pipe for mixing the light, wherein the primary optic 1021 is
positioned
proximate to the light-emitting elements and the primary optic is configured
to enhance
light ex-traction from the light-emitting elements.
[00144] The substrate upon which the light-emitting elements are mounted is
designed to be highly thermally conductive and configured to interface with a
heat pipe
to provide a means for efficient heat transfer away from the light-emitting
elements.
[00145] The LED PCB 1023 has mounted thereon the control module, one or more
sensors and communication system which are all configured for communication
with the
light-emitting elements. The substrate 1005 upon which the light-emitting
elements are
mounted is inferiorly mounted to the LED PCB, wherein a hole is located at the
location
of the light-emitting elements.
[00146] The disclosure of all patents, publications, including published
patent
applications, and database entries referenced in this specification are
specifically
incorporated by reference in their entirety to the same extent as if each such
individual
patent, publication, and database entry were specifically and individually
indicated to be
incorporated by reference.
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