U.S. patent application number 10/113834 was filed with the patent office on 2002-11-28 for systems and methods for converting illumination.
Invention is credited to Ducharme, Alfred D..
Application Number | 20020176259 10/113834 |
Document ID | / |
Family ID | 34199371 |
Filed Date | 2002-11-28 |
United States Patent
Application |
20020176259 |
Kind Code |
A1 |
Ducharme, Alfred D. |
November 28, 2002 |
Systems and methods for converting illumination
Abstract
An illumination system according to the principles of the
invention may include a first LED and a carrier material. The
carrier material may be comprised of plastic, synthetic material,
polymer, latex, rubber or other material. The carrier material may
also contain a phosphor, fluorescent material, organic fluorescent
material, inorganic fluorescent material, impregnated phosphor,
phosphor particles, phosphor material, YAG:Ce phosphor, or other
material for converting electromagnetic radiation into illumination
or visible light. The illumination system may also have a housing
wherein the housing has an open end. The first LED may be arranged
to project emitted light through the open end and the carrier
material may be cooperatively arranged with the housing such that
the emitted light from the first LED is projected through the
carrier material.
Inventors: |
Ducharme, Alfred D.;
(Orlando, FL) |
Correspondence
Address: |
WOLF GREENFIELD & SACKS, PC
FEDERAL RESERVE PLAZA
600 ATLANTIC AVENUE
BOSTON
MA
02210-2211
US
|
Family ID: |
34199371 |
Appl. No.: |
10/113834 |
Filed: |
April 1, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10113834 |
Apr 1, 2002 |
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09716819 |
Nov 20, 2000 |
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60280215 |
Mar 30, 2001 |
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60166533 |
Nov 18, 1999 |
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60201140 |
May 2, 2000 |
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60235678 |
Sep 27, 2000 |
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Current U.S.
Class: |
362/545 ;
362/800 |
Current CPC
Class: |
F21V 3/04 20130101; F21V
13/08 20130101; H05B 47/165 20200101; H05B 45/20 20200101; F21V
9/38 20180201; F21Y 2113/13 20160801; F21Y 2115/10 20160801; H05B
45/22 20200101; F21V 9/32 20180201; F21W 2131/406 20130101; F21Y
2103/10 20160801; Y10S 362/80 20130101; F21K 9/64 20160801 |
Class at
Publication: |
362/545 ;
362/800 |
International
Class: |
F21V 021/00 |
Claims
1. An illumination system comprising: at least one LED; a
conversion material comprising at least one of a plastic, a
synthetic material, a polymer, latex, rubber, a phosphor, a
fluorescent material, an organic fluorescent material, an inorganic
fluorescent material, an impregnated phosphor, phosphor particles,
a phosphor material, and a YAG:Ce phosphor; and a housing having an
open end, wherein: the at least one LED is arranged to project
emitted light through the open end of the housing; and the
conversion material is cooperatively arranged with the housing such
that the emitted light from the at least one LED is projected
through the material.
Description
[0001] CROSS REFERENCES TO RELATED APPLICATIONS
[0002] This application claims the benefit, under 35 U.S.C.
.sctn.119(e), of U.S. provisional application Ser. No. 60/280,215,
filed Mar. 30, 2001, entitled "Systems and Methods for Converting
Illumination. This application also claims the benefit, under 35
U.S.C. .sctn.120, as a continuation-in-part (CIP) of U.S.
non-provisional patent application Ser. No. 09/716,819, filed Nov.
20, 2000, entitled "Systems and Methods for Generating and
Modulating Illumination Conditions." This application also claims
the benefit, under 35 U.S.C. .sctn.120, of the following U.S.
provisional applications, as the above-identified U.S.
non-provisional application similarly is entitled to the benefit of
the following applications:
[0003] Ser. No. 60/166,533, filed Nov. 18, 1999, entitled
"Designing Lights With LED Spectrum;
[0004] Ser. No. 60/235,678, filed Sep. 27, 2000, entitled
"Ultraviolet Light Emitting Diode Device; and
[0005] Ser. No. 60/201,140, filed May 2, 2000, entitled "Systems
and Methods for Modulating Illumination Conditions.
[0006] Each of the foregoing applications hereby is incorporated
herein by reference.
BACKGROUND
[0007] 1. Field of the Invention
[0008] The present invention relates to light emitting diode
devices. In particular the invention relates to illumination
systems using LEDs along with various materials to convert the
light emitted from the LEDs.
[0009] 2. Description of Related Art
[0010] Light emitting diodes (LEDs) are becoming a viable
alternative to conventional light sources in many applications. For
years, LEDs were used as indicator lights because of their long
life, reliability and energy efficiency. Most recently, LEDs have
been making a big impact in the field of illumination. LEDs have
been exponentially increasing in brightness over the years, leading
to their acceptance into the field of illumination.
[0011] While many LEDs provide nearly 100,000 hours of performance,
white LEDs have significantly shorter lives. Both the expected
lifetime and the lumen maintenance over the lifetime are
significantly reduced compared to conventional non-white
high-brightness LEDs. There may be several reasons for this
drop-off in performance. The white LED package uses a blue or
ultraviolet die to pump an active phosphor impregnated in the die,
package or epoxy used in the package of the LED to produce white
light. The phosphor converts the blue or ultraviolet wavelengths
produced by the die into a white light. The die itself usually
produces a rather narrow spectrum of blue light and the phosphor
down converts this energy to longer wavelength energy. The
resulting spectrum is shifted from the narrow blue towards the
middle of the visible spectrum and the spectrum is typically
broadened. White LEDs are available through companies such as
Nichia. Because of imperfections in this down conversion, the white
LEDs produce a very blue-white light meaning the color temperature
of the illumination and the quality of the light is not acceptable
for many general illumination applications.
SUMMARY OF THE INVENTION
[0012] In various embodiments, methods and systems are provided for
improved white light LED systems. In an embodiment, the present
invention is an apparatus for providing an efficient,
computer-controlled, multicolored illumination network capable of
high performance and rapid color selection and change.
[0013] An embodiment of an illumination system may include a first
LED and a carrier material. The carrier material may be comprised
of plastic, synthetic material, polymer, latex, rubber or other
material. The carrier material includes a phosphor, fluorescent
material, organic fluorescent material, inorganic fluorescent
material, impregnated phosphor, phosphor particles, phosphor
material, YAG:Ce phosphor, or other material which can convert
electromagnetic radiation into illumination and/or visible light.
The illumination system may also have a housing wherein the housing
has an open end. The first LED may be arranged to project emitted
light through the open end and the carrier material may be
cooperatively arranged with the housing such that the emitted light
from the first LED is projected through the carrier material.
[0014] Another embodiment of an illumination system may include a
first LED and a carrier material. The carrier material may be
comprised of plastic, synthetic material, polymer, latex, rubber or
other material. The carrier material may also contain a phosphor,
fluorescent material, organic fluorescent material, inorganic
fluorescent material, impregnated phosphor, phosphor particles,
phosphor material, YAG:Ce phosphor, or other material which can
convert electromagnetic radiation into illumination and/or visible
light. The illumination system may also include a housing wherein
the housing may be made of a transparent material, translucent
material, semi-transparent material, semi-translucent material or
other material capable of at least partial transmission of
electromagnetic radiation. The LED may be arranged to project
emitted light through the housing. The carrier material may be
cooperatively arranged with the housing such that the emitted light
from the first LED is projected through the material.
[0015] Another embodiment of an illumination system may include a
first LED and a housing. The housing may be formed from a carrier
material; wherein the material comprises plastic, synthetic,
polymer, latex, rubber or other material. The carrier material may
further comprise a phosphor, fluorescent material, organic
fluorescent material, inorganic fluorescent material, impregnated
phosphor, phosphor particles, phosphor material, YAG:Ce phosphor,
or other material which can convert electromagnetic radiation into
illumination and/or visible light. The LEDs may be arranged to
project emitted light through the housing.
[0016] Another embodiment of an illumination system may include a
second LED wherein the second LED produces a different spectral
distribution from the first LED. The second LED may produce amber
light, yellow light, red light, or any other light or
electromagnetic radiation.
[0017] Yet another embodiment of an illumination system may include
two different colored LEDs and a housing. The housing may comprise
a transparent material, translucent material, semi-transparent
material, semi-translucent material, or other material capable of
at least partial transmission of electromagnetic radiation. The two
different colored LEDs may be arranged to project light through the
housing. A carrier material comprising plastic, synthetic, polymer,
latex, rubber or other material may be associated with the housing.
The carrier material may further comprise a phosphor. fluorescent
material, organic fluorescent material, inorganic fluorescent
material, impregnated phosphor, phosphor particles, phosphor
material, YAG:Ce phosphor or other material which can convert
electromagnetic radiation into illumination and/or visible light.
The first material may be selectively arranged in cooperation with
the housing such that the light produced by one of the two LEDs is
projected through the carrier material and light produced by one of
the two LEDs is projected from the illumination system without
passing through the carrier material.
[0018] At least one of the two LEDs in an embodiment may produce
blue light, violet light, ultraviolet light or other light or
electromagnetic radiation. At least one of the two LEDs in an
embodiment may produce amber light, yellow light, red light or
other light.
[0019] In an embodiment, one of the LEDs may produce
short-wavelength light. The short-wavelength LED produces may
produce blue light, violet light, ultraviolet light or other
short-wavelength light. The carrier material may be selectively
arranged in strips such that the light from the short-wavelength
LED is projected through the first material.
[0020] The carrier material may alternatively be selectively
arranged as a continuous sheet with holes such that the light from
the short-wavelength LED is projected through the carrier
material.
[0021] The system may comprise a first carrier material and a
second material. The first carrier material may be comprised of
plastic, synthetic, polymer, latex, rubber or other material. The
first material may further comprise a phosphor, fluorescent
material, organic fluorescent material, inorganic fluorescent
material, impregnated phosphor, phosphor particles, phosphor
material, YAG:Ce phosphor or other material which can convert
electromagnetic radiation into illumination and/or visible light.
The second carrier material may be comprised of plastic, synthetic,
polymer, latex, rubber or other material. The second material may
further comprise a phosphor, fluorescent material, organic
fluorescent material, inorganic fluorescent material, impregnated
phosphor, phosphor particles, phosphor material, YAG:Ce phosphor or
other material which can convert electromagnetic radiation into
illumination and/or visible light. The second carrier material may
be different than the first carrier material. The first carrier
material may be selectively arranged such that the light from at
least one of the short-wavelength LED is projected through the
first carrier material; and wherein the second carrier material may
be selectively arranged such that the light from the
short-wavelength LED is projected through the second carrier
material.
[0022] In any of the above embodiments the first LED may emit blue
light, violet light, ultraviolet light or other light. The first
LED may emit a peak wavelength of approximately 480 nm in one
embodiment or any wavelength(s) less than 550 nm in another
embodiment. In an embodiment of the invention, the housing may form
a reflector housing, linear lamp housing, cove housing, MR16
housing, C-Series housing, ColorBlast housing, a lighting fixture
housing, or other housing. Some housings which may be used are
described in U.S. patent app. Ser. No. 09/669,121 for "Multicolored
LED Lighting Method and Apparatus," U.S. patent app. Ser. No.
60/235,966 for "Optical System for Light-Emitting Semiconductors,"
U.S. patent application Ser. No. 09/333,739 for "Diffuse
Illumination Systems and Methods," U.S. patent app. Ser. No.
29/138,407 for "Lighting Fixture," U.S. patent app. Ser. No.
09/215,624 for "Smart Light Bulb," and U.S. patent app. Ser. No.
09/805,368 for "Light-emitting Diode based products." The entire
disclosures of each of these applications is incorporated herein by
reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The following figures depict certain illustrative
embodiments of the invention which like reference numerals refer to
like elements. These depicted embodiments arc be understood as
illustrative of the invention and not as limiting in any way.
[0024] FIG. 1 depicts an exemplary lighting system;
[0025] FIG. 2 illustrates an embodiment of an illumination
system;
[0026] FIG. 3 shows an embodiment of an illumination system with
alternative sectional views;
[0027] FIGS. 3A, 3B, 3C, and 3D show cross sectional view of the
embodiment of FIG. 3 at the line A-A;
[0028] FIG. 4 depicts an embodiment of an illumination system with
selectively arranged material;
[0029] FIG. 5 illustrates an embodiment of an illumination system
with selectively arranged material;
[0030] FIG. 6 illustrates an embodiment of an illumination system
with two different types of material; and
[0031] FIG. 7 shows another embodiment of an illumination
system.
DETAILED DESCRIPTION
[0032] The description below pertains to several illustrative
embodiments of the invention. Although many variations of the
invention may be envisioned by one skilled in the art, such
variations and improvements are intended to fall within the compass
of this disclosure. Thus, the scope of the invention is not to be
limited in any way by the disclosure below.
[0033] As used herein, the term "LED" means any system that is
capable of receiving electrical signal and producing a color of
light in response to the signal. Thus, the term "LED" should be
understood to include light emitting diodes of all types, light
emitting polymers, semiconductor dies that produce light in
response to current, organic LEDs, electro-luminescent strips, and
other such systems. In an embodiment, an "LED" may refer to a
single light emitting diode having multiple semiconductor dies that
are individually controlled. It should also be understood that the
term "LED" does not restrict the package type of the LED. The term
"LED" includes packaged LEDs, non-packaged LEDs, surface mount
LEDs, chip on board LEDs and LEDs of all other configurations. The
term "LED" also includes LEDs packaged or associated with phosphor
wherein the phosphor may convert energy from the LED to a different
wavelength.
[0034] An LED system is one type of illumination source. As used
herein "illumination source" should be understood to include all
illumination and/or light sources, including LED systems, as well
as incandescent sources, including filament lamps, pyro-luminescent
sources, such as flames, candle-luminescent sources, such as gas
mantles and carbon arch radiation sources, as well as
photo-luminescent sources, including gaseous discharges,
fluorescent sources, phosphorescence sources, lasers,
electro-luminescent sources, such as electro-luminescent lamps,
light emitting diodes, and cathode luminescent sources using
electronic satiation, as well as miscellaneous luminescent sources
including galvano-luminescent sources, crystallo-luminescent
sources, kine-luminescent sources, thermo-luminescent sources,
triboluminescent sources, sonoluminescent sources, and
radioluminescent sources. Illumination sources may also include
luminescent polymers capable of producing primary colors.
[0035] The term "illuminate" should be understood to refer to the
production of a frequency of radiation by an illumination source.
The term "color" should be understood to refer to any frequency of
radiation within a spectrum; that is, a "color," as used herein,
should be understood to encompass a frequency or combination of
frequencies not only of the visible spectrum, but also frequencies
in the infrared and ultraviolet areas of the spectrum, and in other
areas of the electromagnetic spectrum.
[0036] There have been significant advances in the control of LEDs.
U.S. patents in the field of LED control include U.S. Pat. Nos.
6,016,038, 6,150,774, and 6,166,496. U.S. patent application Ser.
No. 09/716,819 for "Systems and Methods for Generating and
Modulating Illumination Conditions" also describes, among other
things, systems and controls. The entire disclosure of all these
documents is herein incorporated by reference.
[0037] One embodiment of U.S. patent application Ser. No.
09/716,819 teaches of combining white LEDs with LEDs of different
colors to produce a high quality white light with acceptable and/or
alterable color temperature. One embodiment also teaches of
modulating the power to at least one of the LEDs in the
illumination system for controlling the color temperature of the
light. This can, for example, be useful for modulating the
illumination conditions within a room. This could be used to change
the color temperature in a room from a warm sunrise color in the
morning through a cooler noon-time color and back to an evening
sunset condition.
[0038] FIG. 1 illustrates a block diagram of one embodiment of an
illumination system 100. A processor 2 is associated with several
controllers 3. The controllers 3 control the power to the LEDs 4.
As used herein, the term processor may refer to any system for
processing electronic signals. A processor may include a
microprocessor, microcontroller, programmable digital signal
processor, other programmable device, a controller, addressable
controller, microprocessor, microcontroller, addressable
microprocessor, computer, programmable processor, programmable
controller, dedicated Processor, dedicated controller, integrated
circuit, control circuit or other processor. A processor may also,
or instead, include an application specific integrated circuit, a
programmable gate array, programmable array logic, a programmable
logic device, a digital signal processor, an analog-to-digital
converter, a digital-to-analog converter, or any other device that
may be configured to process electronic signals. In addition, a
processor may include discrete circuitry such as passive or active
analog components including resistors, capacitors, inductors,
transistors, operational amplifiers, and so forth, as well as
discrete digital components such as logic components, shift
registers, latches, or any other separately packaged chip or other
component for realizing a digital function. Any combination of the
above circuits and components, whether packaged discretely, as a
chip, as a chipset, or as a die, may be suitably adapted to use as
a processor as described herein. It will further be appreciated
that the term processor may apply to an integrated system, such as
a personal computer, network server, or other system that may
operate autonomously or in response to commands to process
electronic signals such as those described herein. Where a
processor includes a programmable device such as the microprocessor
or microcontroller mentioned above, the processor may further
include computer executable code that controls operation of the
programmable device. In an embodiment, the processor 2 is Microchip
PIC processor 12C672 and the LEDs 4 may be red, green and blue.
[0039] The controller 3 may be a pulse width modulator, pulse
amplitude modulator, pulse displacement modulator, resistor ladder,
current source, voltage source, voltage ladder, switch, transistor,
voltage controller, or other controller. The controller controls
the current, voltage or power through the LED 4. The controller
also has a signal input wherein the controller is responsive to a
signal received by the signal input. The signal input is associated
with the processor such that the processor communicates signals to
the signal input and the controller regulates the current, voltage
and or power through the LED. In an embodiment, several LEDs with
different spectral output may be used. Each of these colors may be
driven through separate controllers. The processor and controller
may be incorporated into one device. This device may power
capabilities to drive several LEDs in a string or it may only be
able to support one or a few LEDs directly. The processor and
controller may also be separate devices. By controlling the LEDs
independently, color mixing can be achieved for the creation of
lighting effects. In an embodiment, memory 6 is also be provided.
The memory 6 is capable of storing algorithms, tables, or values
associated with the control signals. The memory 6 may store
programs for controlling the LEDs 4. The memory may be memory,
read-only memory, programmable memory, programmable read-only
memory, electronically erasable programmable read-only memory,
random access memory, dynamic random access memory, double data
rate random access memory, Rambus direct random access memory,
flash memory, or any other volatile or non-volatile memory for
storing program instructions, program data, address information,
and program output or other intermediate or final results. A
program, for example, may store control signals to operate several
different colored LEDs 4. A user interface I may also be associated
with the processor 2. The user interface may be used to select a
program from memory, modify a program from memory, modify a program
parameter from memory, select an external signal or provide other
user interface solutions. Several methods of color mixing and pulse
width modulation control are disclosed in U.S. Pat. No. 6,016,038
"Multicolored LED Lighting Method and Apparatus," the entire
disclosure of which is incorporated by reference herein. The
processor 2 can also be addressable to receive programming signals
addressed to it.
[0040] Another useful interface is an interface that is associated
with a power source. An energy storage element can be associated
with a power source. The energy storage device cart also be
associated with a processor. The energy storage element may be a
capacitor, non-volatile memory, battery backed memory, relay,
storage device or other energy storage element. The element may
communicate a logic high and a logic low signal to the processor
depending on the state of the element. For example, the element may
communicate a low logic signal when the device is connected to the
power source and a high logic signal when the device is
disconnected from the power source. The high logic signal may
change to a low logic signal following a predetermined period of
time and the processor may be monitoring the signal. The lighting
device could be programmed such that a last lighting program may be
operating when the device is de-energized. If the device is
re-energized within a predetermined period, while the logic signal
is still high, the device may select a new program from memory to
execute. If the device is not re-energized within the predetermined
period, the device may start up in the last lighting program or a
default program or vice-versa. A non-volatile memory, battery
backed memory or other memory may be provided such that the last
program is remembered. The technique can be used to change the
program, a program parameter or other setting. This technique can
be used in a device that does not include a separate user interface
by turning the power to the lighting device off and on. A separate
switch could also be employed to provide the user interface as well
as an on/off switch.
[0041] As used herein the term "convert" shall mean a process
method, or similar thing that changes the properties of the
electromagnetic radiation generated by illumination source. This
process may also be generally referred to as down converting. This
process is generally used to describe an active phosphor as in a
fluorescent lamp for example. The phosphor coating on a fluorescent
lamp converts (or down converts) the ultraviolet energy produced by
the mercury discharge into visible light. Different phosphors can
be combined into one mixture such that several different conversion
processes occur simultaneously. Many fluorescent lamps use three
phosphors or a tri-phosphor to convert the ultraviolet light into
three different spectral power distributions. This conversion
generally results in the ultraviolet light appearing as "white
light" in the visible spectrum. Converting within this disclosure
can be from any wavelength(s) of electromagnetic radiation into any
other wavelength(s) of electromagnetic radiation including the same
wavelength(s).
[0042] An illumination system 200 according to the principles of
the invention may include a carrier material 204. The system 200
may also include a system 100 with one or more LEDs 4. The carrier
material 204 may be arranged such that illumination from an LED 4
is projected through the carrier material 204. The carrier material
is designed to convert the light received into a different spectral
power distribution. The LED spectral power distribution may be
narrow and the carrier material 204 may be used to AR the spectra
and/or broaden the spectral power distribution or otherwise change
the spectral power distribution. The carrier material 204 may be
made of plastic, synthetic material, polymer, latex, rubber or
other material. The carrier material 204 may also be comprised of a
phosphor, fluorescent material, organic fluorescent material,
inorganic fluorescent material, impregnated phosphor, phosphor
particles, phosphor material, YAG:Ce phosphor, or other material to
convert the electromagnetic radiation projected from the LED or
other illumination source into illumination and/or visible light.
Combinations of the above carrier material 204 or material to
convert are also included an embodiment of the invention. One
possible carrier material with these properties can be purchased
from ARI International, 2015 S. Arlington Heights, Ill. 60005. ARI
International has a rubber-based product referred to as White Cap.
ARI International offers several different materials to convert the
light from a blue LED into several different colors.
[0043] The illumination system may also comprise a housing 202. The
housing 202 may be designed to house the LED system 100. The
carrier material 204 may be cooperatively arranged with the housing
such that the illumination from at least one of the LEDs passes
through the carrier material 204. FIG. 2 illustrates a
configuration according to the principles of the invention where
the carrier material 204 is placed over the exit aperture or open
end 208 of the housing. FIG. 7 illustrates another configuration
according to the principles of the invention where the carrier
material 204 is placed over the inlet to the reflector. The carrier
material 204 can be arranged in any position such that the
illumination from any of the LEDs passes through the carrier
material.
[0044] FIGS. 3, 3A, 3B, 3C, and 3D illustrate another configuration
of an illumination system according to the principles of the
invention. This system includes a housing 202 wherein the LEDs 4
are substantially contained. In this configuration, the LED
illumination is projected through the housing 202. The housing 202
may be made of a transparent material, translucent material,
semi-transparent material, semi-translucent material, or other
material designed to allow for the transmission or partial
transmission of electromagnetic radiation. A carrier material 204
may be cooperatively associated with the housing 202 such that the
electromagnetic radiation emitted from at least one of the LEDs
passes through the carrier material 204. For example, FIG. 3A shows
the carrier material 204 enclosing the housing 202. FIG. 3B shows a
system where the carrier material 204 is selectively arranged to
cover a portion of the housing. FIG. 3C shows another alternative
example where the housing 202 is formed of the carrier material
202. FIG. 3D shows the carrier material selectively arranged to
cover a portion of the housing. With this arrangement, some of the
light from an LED may be converted while some of the light from the
LED may not be converted.
[0045] FIG. 4 illustrates another exemplary illumination system
where the carrier material 204 is selectively arranged. The carrier
material 204 may cover or be formed in sections of the housing
while not covering other sections. For instance, "holes" or
openings may be left in the carrier material 204 to reveal housing
202 or so that there is no carrier material at the "hole." This
arrangement may be designed to allow the carrier material 204 to
cover certain LEDs while allowing other LEDs to project light
without passing through the carrier material. A useful example of
this arrangement could be where at least two different colored LEDs
are provided in the illumination system. The LEDs may be
alternating blue and amber for example. The blue LEDs may be
arranged to project illumination through the carrier material 204
and the amber LEDs may be arranged to project illumination through
the housing 202 and/or hole without passing through the carrier
material 204. This arrangement could be useful for producing a
different color temperature light or variable color temperature
light or other lighting effects. U.S. patent application Ser. No.
09/716,819 describes some methods of modulating illumination
conditions which could be used for such radiation and the entire
disclosure is hereby incorporated by reference herein. The system
could be controlled such that the intensity of each of the colors
within the system could be modulated to change the illumination
conditions produced by the system. For example, the blue LED may be
driven at a high level and the amber LED power may be varied. The
light projected from the several LEDs combines and this technique
can be used to change the overall color of the system. In this
example, the carrier material 204 is used to convert the blue LED
radiation to white radiation and the amber LED is used to lower the
color temperature of the resultant radiation. It will be obvious to
one of ordinary skill in the art that there are many combinations
of LEDs that could be used to produce useful colors, illumination,
and changing illumination effects. Some of these are also disclosed
in the above referenced U.S. patent application Ser. No.
09/716,819.
[0046] Another configuration of a system according to the
principles of the invention is illustrated in FIG. 5. The carrier
material 204 is selectively arranged in strips to cover portions of
the housing. The strips may be arranged such that the illumination
from at least one of the LEDs is projected through the carrier
material 204.
[0047] Another useful embodiment according to the principles of the
invention is depicted in FIG. 6. In this example, the illumination
system is using at two or more different types of carrier material
201 The LEDs 4 may produce the same color or they may be different
colors. Providing a system with one or more LEDs of the same color
can be useful. For example, if a blue LED is provided along with
two different carrier materials, the light projected through the
two different carrier materials will produce two different colors.
One carrier material may produce a high color temperature white
light while the other carrier material produces a low color
temperature white light. The illumination from the system would
produce a combined color temperature from the two carrier materials
and allow for control over the color temperature. A system with two
blue LEDs, for example, along with two different types of material
may be useful for producing a combined color from the system. The
illumination conditions could also be adjusted by modulating the
power of the separate LEDs. Through this modulation, the light
emitted through one or more of the carrier materials can be changed
to change the overall color emitted from the system.
[0048] In yet another embodiment of the invention, illumination
systems having three or more colors of LEDs could be generated with
any number of these LEDs having their illumination converted by one
or more types of carrier material 204. The principles of building
such a system extend from the above examples and would be
understood by one of skill in the art.
[0049] In another configuration there can be partitions, reflectors
or other dividers separating LEDs so that light from any single LED
can be directed at a particular location such as carrier material
204, housing 202 or a hole while limiting spill from the LED into
the other locations.
[0050] All articles, patents, and other references set forth above
are hereby incorporated by reference. While the invention has been
disclosed in connection with the embodiments shown and described in
detail, various equivalents, modifications, and improvements will
be apparent to one of ordinary skill in the art from the above
description. Such equivalents, modifications, and improvements are
encompassed herein.
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