RYANAKAMENACLSEAAEALA
`
`US 20030230765A1
`
`as) United States
`a2) Patent Application Publication (i) Pub. No.: US 2003/0230765 Al
` Dry (43) Pub. Date: Dec. 18, 2003
`
`
`(54) LIGHT EMITTING DIODE LIGHT SOURCE
`Publication Classification
`(75)
`Inventor:
`Joel M. Dry, Winters, TX (US)
`(51) Unt, C17 ccnnsnsnsstnnnneseenni HOLL 31/0328
`(52) US. Che cessssnncneminsnnnnnnsnnninnnnnnsn 257/200
`
`Correspondence Address:
`DONALD J LENKSZUS
`PO BOX 3064
`CAREFREE, AZ 85377-3064 (US)
`.
`:
`.
`(73) Assignee: OPTOLUM,INC., Scottsdale, AZ
`(21) Appl. No.:
`10/430,698
`(22)
`Filed:
`May5, 2003
`Related U.S. Application Data
`(63) Continuation-in-part of application No. 10/156,810,
`filed on May 29, 2002, now Pat. No. 6,573,536.
`
`(57)
`
`ABSTRACT
`
`A light source that utilizes light emitting diodes that emit
`white light is disclosed. The diodes ae mounted on an
`elongate member having at least two surfaces upon which
`the light emitting diodes are mounted. The elongate member
`is thermally conductive and is utilized to cool
`the light
`emitting diodes.In theillustrative embodiment, the elongate
`memberis a tubular member through which a heat transfer
`medium flows. A cooling or fluid movement device coupled
`with the clongate thermally conductive member enhances
`cooling of ihe light emitting diodes.
`
`102 111
`
`102
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`1
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`APPLE 1052
`Apple v. Masimo
`IPR2022-01299
`
`APPLE 1052
`Apple v. Masimo
`IPR2022-01299
`
`1
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`

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`Patent Application Publication Dec. 18,2003 Sheet 1 of 4
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`US 2003/0230765 Al
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`FIG.3
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`FIG.1
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`2
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`Patent Application Publication Dec. 18,2003 Sheet 2 of 4
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`Patent Application Publication Dec. 18, 2003
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`Sheet 3 of 4
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`US 2003/0230765 Al
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`201
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`FIG. 7
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`201
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`FIG. 8
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`4
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`Patent Application Publication Dec. 18,2003 Sheet 4 of 4
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`US 2003/0230765 Al
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`199
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` Cooling
`
`Device
`
`303
`
`109
`
`109
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`
`
`Control
`
`305
`
`FIG. 9
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`US 2003/0230765 Al
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`Dec. 18, 2003
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`LIGHT EMITTING DIODE LIGHT SOURCE
`
`RELATED APPLICATIONS
`
`{0001] This application is a continuation-in-part of my
`co-pending application Ser. No. 10/156,810 filed May29,
`2002.
`
`FIELD OF THE INVENTION
`
`[0002] This invention pertains to lighting sources, in gen-
`eral, and to a lighting source that utilizes Light Emitting
`Diodes (LED’s), in particular
`
`BACKGROUND OF THE INVENTION
`
`[0003] LED’s have many advantages as light sources.
`However, in the past LED’s have found application only as
`specialized light sources such as for vehicle brake lights, and
`other vehicle related lighting, and recently as flashlights. In
`these prior applications, the LED’s are typically mounted in
`a planar fashion in a single plane that is disposed so as to be
`perpendicular to the viewing area. Typically the LED planar
`array is not used to provide illumination, but to provide
`signaling.
`
`[0004] Recent attempts to provide LED light sources as
`sources of illumination have been few, and generally unsat-
`isfactory from a general lighting standpoint.
`
`It is highly desirable to provide a light source
`[0005]
`utilizing LED’s that provides sufficient light output so as to
`be used as a general lighting source rather than as a signaling
`source.
`
`[0006] One problem that has limited the use of LED’s to
`specialty signaling and limited general illumination sources
`is that LED’s typically generate significant amountsofheat.
`The heat is such that unless the heat is dissipated, the LED
`internal
`temperature will
`rise causing degradation or
`destruction of the LED.
`
`It is therefore further desirable to provide an LED
`[0007]
`light source that efficiently conducts heat away from the
`LED’s.
`
`SUMMARY OF THE INVENTION
`
`In accordance with the principles of the invention,
`[0008]
`an improved light source is provided. The light source
`includes an elongate thermally conductive member having
`an outer surface. A plurality of light emitting diodes is
`carried on the elongate memberouter surface. At least some
`of the light emitting diodes are disposed in a first plane and
`others of said light emitting diodes are disposed in a second
`plane not coextensive with the first plane. Electrical con-
`ductors are carried by the elongate thermally conductive
`member and are connected to the plurality of light emitting
`diodes to supply electrical power thereto. The elongate
`thermally conductive member conducts heat away from the
`light emitting diodes to a thermally conductive fluid
`medium. A cooling device is utilized to remove heat from
`the light emitting diodes. In one aspect of the invention, the
`cooling device comprises a fluid moving device utilized to
`cause the fluid medium to flow to cause cooling of the
`elongate thermally conductive member and therefore to
`dissipate heat from the light emitting diodes. In another
`aspect of the invention,
`the cooling device may be an
`
`electronic or solid state device such as a Piezoelectric device
`or a device that uses the Peltier effect, known as a Peltier
`device.
`
`In accordance with the principles of the invention,
`[0009]
`a temperature sensor is provided to determine the tempera-
`ture of the light emitting diodes. The temperature sensor is
`coupled to a controller that monitors the temperature and
`controls the cooling device to vary the degree of cooling in
`accordance with the monitored temperature. In addition, the
`controller can be used to control the power provided to the
`light emitting diodes in response to the monitored tempera-
`ture. Still further, the controller may be operated to control
`the light output provided by the light emitting diodes.
`
`In the illustrative embodimentof the invention, the
`[0010]
`fluid medium is air and the fluid moving device is an air
`moving device.
`
`In accordance with one aspect of the invention, an
`(0011]
`illustrative embodiment of the invention utilizes light emit-
`ting diodes that emit white light. However, other embodi-
`ments of the invention mayutilize light emitting diodesthat
`are ofdifferent colors to produce monochromatic light or the
`colors may be chosen to produce white light or other colors.
`
`In accordance with another aspect of the invention
`[0012]
`the elongate thermally conductive member transfers heat
`from the light emitting diodes to a medium within said
`elongate thermally conductive member. In the illustrative
`embodimentof the invention, the medium isair.
`
`In accordance with another aspect of the invention,
`(0013]
`the elongate thermally conductive member has one or more
`projections or fins to enhance heat transfer to the medium.
`The projectionsor fins may be disposed on the outer surface
`or inner surtace of the elongate thermally conductive mem-
`ber or may be disposed on both the outer and inner surfaces.
`
`In accordance with another aspect of the invention
`(0014]
`the elongate thermally conductive member comprises a tube.
`In one embodimentof the invention, the tube has a cross-
`section in the shape of a polygon. In another embodiment of
`the invention, the tube has a cross-section having flat por-
`tions.
`
`In accordance with another embodiment of the
`[0015]
`invention, the elongate thermally conductive member com-
`prises a channel.
`
`In accordance with the principles of the invention,
`[0016]
`the elongate thermally conductive member may comprise an
`extrusion, and the extrusion can be highly thermally con-
`ductive material such as aluminum.
`
`In one preferred embodiment of the invention the
`[0017]
`elongate thermally conductive memberis a tubular member.
`The tubular member has a polygon cross-section. However,
`other embodiments my have a tubular memberoftriangular
`cross-section.
`
`In one embodiment of the invention, a flexible
`[0018]
`circuit is carried on a surface of said elongate thermally
`conductive member; the flexible circuit includes the electri-
`cal conductors.
`
`the flexible
`In another aspect of the invention,
`{0019]
`circuit comprises a plurality of apertures for receiving said
`plurality of light emitting diodes. Each of the light emitting
`diodes is disposed in a corresponding one of the apertures
`
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`US 2003/0230765 Al
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`Dec. 18, 2003
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`and affixed in thermally conductive contact with said elon-
`gate thermally conductive member.
`
`but may in some applications be a fluid other than air to
`provide for greater heat dissipation and cooling.
`
`conductive member
`thermally
`elongate
`[0020] The
`includes a thermal transfer media disposed therein in a flow
`channel.
`
`[0021] At least one clip for mounting the elongate ther-
`mally conductive memberin a fixture may be included.
`
`BRIEF DESCRIPTION OF THE DRAWING
`
`[0033] Cooling device 199 is coupled to elongate ther-
`mally conductive member 101 to enhance cooling of the
`LED’s. Cooling device in one embodimentof the invention
`is a medium moving device in fluid coupling with elongate
`thermally conductive member 101 to enhance the movement
`of medium 102. Medium moving device 199 is utilized to
`enhance fluid medium 102 to flow to cause cooling of the
`elongate thermally conductive member and therefore to
`[0022] The invention will be better understood from a
`dissipate heat fromthe light emitting diodes. Medium mov-
`
`reading of the following detailed description of a preferred ing device 199 inafirst illustrative embodimentis a fan and
`embodimentof the invention taken in conjunction with the
`may be an electromechanical fan, electronic fan, or solid-
`drawingfigures, in which like reference indicationsidentify
`state device such as a piezoelectric fan. In a second embodi-
`like elements, and in which:
`mentof the invention, cooling device 199 may comprise one
`or more solid state cooling devices utilizing the Peltier
`effect, otherwise knownas Peltier devices. Although cooling
`device 199 is shownat one end ofthe light source 100,it will
`be appreciated by those skilled in the art that where solid
`state devices are utilized, a plurality of solid state devices
`may be positioned at locations other than on an end of the
`light source 100. It will also be appreciated by those skilled
`in the art that solid state cooling devices such as Piezoelec-
`tric and Peltier devices are known.
`
`[0023] FIG. 1 is a planar side viewof a light source in
`accordance with the principles of the invention,
`
`[0024]
`FIG. 1;
`
`FIG.2 is a top planar view of the light source of
`
`[0025] FIG. 3 is a perspective view ofthe light source of
`FIG. 1 with mounting clips;
`
`[0026] FIG. 4 is a planar side view of the light source of
`FIG. 3 showing mounting clips separated from the light
`source;
`
`[0027] FIG. 5 is a top view of the light source and
`mounting clips of FIG. 4;
`
`[0028] FIG.6 is a partial cross-section of the light source
`of FIG. 1;
`
`[0029] FIG. 7 is a top view of an alternate elongate
`thermally conductive member,
`
`[0030] FIG.8 is a side view of the memberof FIG.7; and
`
`[0031] FIG. 9 is a block diagram of a control arrangement
`for the light source of the invention.
`
`DETAIT.ED DESCRIPTION
`
`[0032] A light source in accordance with the principles of
`the invention may be used as a decorative lighting element
`or may be utilized as a general illumination device. As
`shownin FIG.1, a light source 100 in accordance with the
`invention includes an elongate thermally conductive mem-
`ber or heat sink 101. Elongate heat sink 101 is formed of a
`material that provides excellent thermal conductivity. Elon-
`gate heat sink 101 in the illustrative cmbodiment of the
`invention is a tubular aluminum extrusion. To improve the
`heat dissipative properties oflight source 100, elongate heat
`sink 101 is configured to provide convective heat dissipation
`and cooling. As more clearly seen in FIG. 2, tubular heat
`sink 101 is hollow and has an interior cavity 103 that
`includes one or more surface discontinuities or heat dissi-
`
`pating protrusions 105. In the illustrative embodiment the
`surface discontinuities or heat dissipating protrusions 105
`are triangular shaped fins, but may take on other shapes. In
`yet other embodiments,
`the surface discontinuilies may
`include apertures or blind bores either alone or in combi-
`nations with heat dissipation protrusions. Protrusions 105
`are integrally formed on the interior of elongate heat sink
`101. In the illustrative embodiment movement of a medium
`102 through elongate heat sink 101 provides cooling.
`Medium 102 utilized in the illustrative embodimentis air,
`
`[0034] Acontroller 300 is provided in accordance with the
`principles of the invention. Controller 300 is coupled to a
`temperature sensor 301 that is disposed on light source 100
`so as to monitor the temperature ofthe light emitting diodes
`109. Controller 300 is utilized to control the rate of cooling
`provided by cooling device 199. It will be appreciated by
`those skilled in the art that although controller 300 and
`sensor 301 are shown separated from each other in the
`drawing, that such separation is provided merely for clarity
`in understanding the invention and controller 300 and sensor
`301 may be fabricated as a single integrated device.
`
`[0035] The exterior surface 107 of elongate heat sink 101
`has a plurality of Light Emitting Diodes 109 disposed
`thercon. Each LED 109 in the illustrative embodiment
`
`comprises a white light emitting LED of a type that provides
`a high light output. Each LED 109 also generates significant
`amount of heat that must be dissipated to avoid thermal
`destruction of the LED. As noted above cooling device 199
`provides cooling to avoid thermal destruction. By combin-
`ing a plurality of LEDs 109 on elongate thermally conduc-
`tive memberorheat sink 101,a high light output light source
`that may be used for general lighting is provided.
`
`[0036] Conductive paths 129 are provided to connect
`LEDs 109 to an electrical connector 111. The conductive
`
`paths may be disposed onanelectrically insulating layer 131
`or layers disposed on exterior surface 107. In the illustrative
`embodiment shown in the drawing figures, the conductive
`paths and insulating layer are provided by means of one or
`more flexible printed circuits 113 that are permanently
`disposed on surface 107. As more easily seen in FIG. 6,
`printed circuit 113 includes an electrically insulating layer
`131 that carries conductive paths 129. As will be appreciated
`by those skilled in the art, other means of providing the
`electrically conductive paths may be provided.
`
`[0037] Flexible printed circuit 113 has LED’s 109
`mounted to it in a variety of orientations ranging from 360
`degrees to 180 degrees and possibly others depending on the
`application. Electrical connector 111 is disposed at one end
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`Dec. 18, 2003
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`of printed circuit 113. Connector 113 is coupleable to a
`separate power supply to receive electrical current. Flexible
`printed circuit 113, in the illustrative embodimentis coated
`with a non-electrically conductive epoxy that may be
`infused with optically reflective materials. Flexible printed
`circuit 113 is adhered to the tube 101 with a heat conducting
`epoxyto aid in the transmission of the heat from LEDs 109
`to tube 101. Flexible printed circuit 113 has mounting holes
`134 for receiving LEDs 109 such that the backs of LEDs 109
`are in thermal contact with the tube surface 107.
`
`[0042] Light source 100 is mounted into a fixture and
`retained in position by mounting clips 121,123 as most
`clearly seen in FIGS. 3, 4, and 5 Lach ofthe clips is shaped
`so as to engage and retain light source 100. Each clip is
`affixed on one surface 122, 124 to a light fixture.
`
`[0043] Although light source 100 is shown as comprising
`elongate tubular thermally conductive members or heat
`sinks 101, 201, other extruded elongate members may be
`used such as channels.
`
`[0038] Tubular heat sink 101 in the illustrative embodi-
`mentis formed in the shape of a polygon and may have any
`number of sides. Although tubular heat sink 101 in the
`illustrative embodiment is extruded aluminum, tubular heat
`sink 101may comprise other thermal conductive material.
`Fins 105 may vary in numberand location depending on
`particular LED layouts and wattage In some instances,
`surface discontinuities such as heat dissipation protrusions
`or fins may be added to the exterior surface of tubular heat
`sink 101. In addition, apertures may be added as surface
`discontinuities to the tubular heat sink to enhance heat flow.
`
`[0039] FIGS. 7 and 8 show an alternate elongate ther-
`mally conductive member 201 that has both exterior surface
`discontinuities or heat dissipation protrusionsor fins 205 in
`additionto interior surface discontinuities or heat dissipation
`protrusionsor fins 241.
`
`[0040] Turning now to FIG.9, controller 300 is advanta-
`geously utilized in accordance with the principles of the
`invention. Controller 300 may be any one of a number of
`commercially available controllers. Each such controller is
`programmable and includes a processor, and memory
`(which are not shown). Controller 300 memoryis utilized to
`program operation of the microprocessor. It will be appre-
`ciated by those skilled in the art that controller 300 may be
`integrated into the same chip as sensor 301 andinterface 303
`that is utilized to interface controller 300 to the cooling
`device 199. Controller 300 is programmed so that when
`temperature sensor 301 detects a temperature that is too
`high, cooling device 199 is activated or, if activated at less
`than full capacity, is activated to a higher cooling capacity.
`In addition, controller 300 is coupled to power supply 305,
`which in turn provides power to LED’s 109 at the appro-
`priate voltage level and type via power bus 307, so that the
`amount of power provided to LED’s 109 may also be
`regulated to control the amount of power dissipated by
`LED’s 109. Controller 300 controls the amount of cooling
`provided by cooling device 199. The amount of cooling
`provided by cooling device 199 is increased when tempera-
`ture sensor 301 indicates a predetermined temperature. In
`addition, controller 300 will turn off all LED’s 109 in the
`event that a second predetermined temperature threshold is
`reached or exceeded. Controller 300 also operates to
`increase the power provided to LED’s 109 in the eventthat
`the temperature sensed is below another predetermined
`threshold. Controller 300 has control input 309 to reccive
`control inputs to determine the on-off status of LED’s 109
`and to determine the brightness level output of LED’s 109.
`In addition, controller 300 is programmed to be
`
`responsive to control signals that will command
`[0041]
`controller 300 to brighten or dim the light output of LED’s
`109 Interface 303 is provides the appropriate interface
`between controller 300 and cooling device 199
`
`In the illustrative embodiment shown, cooling by
`[0044]
`flow of air through elongate thermally conductive members
`or tubular heat sinks 101, 201 is utilized such that cool or
`unheated air enters elongate thermally conductive members
`101, 201 by fluid movement device 199, passes over the
`surface discontinuities or heat dissipation protrusions, and
`exits from the opposite end of elongate thermally conductive
`member 101, 201 as heated air. In higher wattage light
`sources, rather than utilizing air as the cooling medium,
`other fluids may be utilized. In particular, convective heat
`pumping maybe used to removeheat fromthe interior of the
`heat sink.
`
`In one particularly advantageous embodiment of
`[0045]
`the invention, the light source of the invention is configured
`to replace compact fluorescentlighting in decorative appli-
`cations.
`
`It will be appreciated by those skilled in the art that
`[0046]
`although the invention has been described in terms of light
`emitting diodes, the invention is equally applicable to other
`non-filament miniature lights sources such as organic light
`emitting diodes (OLED’s) and polymer type light sources.It
`is intendedthat the term “light emitting diode” or “LED” as
`used in the claims is intended to not be limited to solid state
`
`light emitting diodes, but is intended to include such other
`miniature light sources.
`
`It has further been determined that the uniformity
`[0047]
`of light distribution of a light source having an elongate
`thermally conductive member with heat dissipation protru-
`sions or fins 205 on the outer surface of the elongate
`thermally conductive member 201 is enhanced byutilization
`of an appropriately selected coating or treatment to the outer
`or exterior surfaces of elongate thermally conductive mem-
`ber 201. In particular, in a comparison of various surface
`coatings or treatments, it has been found that the use of a
`non-reflective or black surface on the protrusionsor fins 205
`provides a more uniform light output. It has been determined
`that the use of reflective or white surfaces on protrusions
`results in the protrusions producing shadows in the light
`output.
`
`[0048] As will be appreciated by those skilled in theart,
`the principles of the invention are not limited to the use of
`light emitting diodes that emit white light. Different colored
`light emitting diodes may be used to produce monochro-
`matic light or to produce light that is the combination of
`different colors.
`
`[0049] Controller 300 is programmable to be further
`responsive to control signals 309 to control which of dif-
`ferent colored LED’s are activated and the amount of power
`provided to the different colors such that the color output of
`lights source 100 is varied.
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`US 2003/0230765 Al
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`Dec. 18, 2003
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`
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`[0050] Althoughthe invention has been described in terms
`of illustrative embodiments,
`it
`is not
`intended that
`the
`invention be limited to the illustrative embodiments shown
`
`and described. It will be apparent to those skilled in the art
`that various changes and modifications may be madeto the
`embodiments shown and described without departing from
`the spirit or scope of the invention. It is intended that the
`invention be limited only by the claims appended hereto.
`Whatis claimedis:
`1. A light source comprising:
`
`an elongate thermally conductive member having an outer
`surface;
`
`a plurality of light emitting diodes (LED’s) carried on said
`elongate member outer surface at least some of said
`light emitting diodes being disposedin a first plane and
`others of said light emitting diodes being disposed in a
`second plane not coextensive with said first plane;
`
`said elongate thermally conductive member being con-
`figured to conduct heat away from said light emitting
`diodes to fluid contained by said elongate thermally
`conductive member;
`
`lemperature sensing apparatus providing signals repre-
`sentative of the temperature of said light emitting
`diodes; and
`
`a controller coupled to said LED’s andto said temperature
`sensing apparatus for controlling the temperature of
`said LED’s dependent upon predetermined tempera-
`tures.
`
`2. A light source in accordance with claim 1, comprising:
`
`a cooling device coupled to said elongate thermally
`conductive memberto enhance cooling of said LED’s,
`said fluid cooling device being controllable by said
`controller.
`
`3. A light source in accordance with claim 2, wherein:
`
`said cooling device comprises an electromechanical
`device.
`
`4. A light source in accordance with claim 3, whercin:
`
`said electromechanical device comprises a fan.
`5. A light source in accordance with claim 2, wherein:
`
`said cooling device comprises an electronic device.
`6. A light source in accordance with claim 2, wherein:
`
`said cooling device comprises a solid state device.
`7. A light source in accordance with claim 2, wherein:
`
`said cooling device comprises an piezoelectric device.
`8. A light source in accordance with claim 1, wherein:
`
`
`
`said elongate thermally conductive member is configured
`to conduct heat away from said light emitting diodes to
`fluid proximate said elongate member outer surface.
`
`9. A light source in accordance with claim 7, wherein:
`
`said fluid proximate said elongate memberouter surface
`comprises air.
`10. A light source in accordance with claim 2, wherein:
`
`said cooling device comprises a fan.
`11. A light source in accordance with claim 2, wherein:
`
`said cooling device comprises a Peltier device.
`12. A light source in accordance with claim 1, wherein:
`
`said controller controls the amount of power provided to
`each of said LED’s.
`
`13. A light source in accordance with claim 12, wherein:
`
`said controller determines the amount of power provided
`to each of said LED’s based upon control signal inputs.
`14. A light source in accordance with claim 13, wherein:
`
`said controller determines the amount of power provided
`to cach of said LED’s in dependence upon signals
`received from said temperature sensor.
`15. A light source in accordance with claim 1, wherein:
`
`at least some of said light emitting diodes emit colored
`light.
`16. A light source in accordance with claim 15, wherein:
`
`said controller controls each of said light emitting diodes
`to control the color of the light output of said light
`source.
`
`17. A light source comprising:
`
`an elongate thermally conductive member having an outer
`surface,
`
`at least one light emitting diode carried on said elongate
`member outer surface;
`
`said elongate thermally conductive member being con-
`figured to conduct heat away fromsaid at least one light
`emitting diode;
`
`a cooling apparatus coupled to said elongate thermally
`conductive memberto enhance cooling of said at least
`one light emitting diode; and
`
`a controller for controlling operation of said cooling
`apparatus.
`18. A light source in accordance with claim 17, wherein:
`
`said controller controls power providedto saidat least one
`light emitting diode.
`19. A light source in accordance with claim 17 wherein:
`
`said cooling device comprises a Peltier device
`20. A light source in accordance with claim 17 wherein:
`
`said cooling device comprises a Piezoelectric device.
`
`9
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`