Optical integrating cavity lighting system using multiple led light sources

Abstract

A system to provide radiant energy of selectable spectral characteristic (e.g. a selectable color combination) uses an integrating cavity to combine energy of different wavelengths from different sources. The cavity has a diffusely reflective interior surface and an aperture for allowing emission of combined radiant energy. Sources of radiant energy of different wavelengths, typically different-color LEDs, supply radiant energy into the interior of the integrating cavity. In the examples, the points of entry of the energy into the cavity typically are located so that they are not directly visible through the aperture. The cavity effectively integrates the energy of different wavelengths, so that the combined radiant energy emitted through the aperture includes the radiant energy of the various wavelengths. The apparatus also includes a control circuit coupled to the sources for establishing output intensity of radiant energy of each of the sources. Control of the intensity of emission of the sources sets the amount of each wavelength of energy in the combined output and thus determines a spectral characteristic of the radiant energy output through the aperture.

1 - 35 . (canceled) 
     
     
         36 . A lighting device, comprising:
 at least one thermal conduction element;   a plurality of solid state light emitters; and   at least a first reflective element,   wherein said solid state light emitters are mounted on at least a first portion of said thermal conduction element and said first reflective element is positioned such that at least a portion of light emitted from at least one of said solid state light emitters is reflected by said first reflective element, and   wherein a second portion of said thermal conduction element is exposed to ambient air.   
     
     
         37 . A lighting device as recited in  claim 36 , wherein at least a first of said solid state light emitters is a light emitting diode. 
     
     
         38 . A lighting device as recited in  claim 36 , wherein said thermal conduction element defines at least one conduction element opening. 
     
     
         39 . A lighting device as recited in  claim 38 , wherein said conduction element opening is covered by a light transmitting plate, so that light which is emitted by any of said solid state light emitters and which passes through said conduction element opening must pass through said light transmitting plate. 
     
     
         40 . A lighting device as recited in  claim 38 , wherein said thermal conduction element surrounds said conduction element opening. 
     
     
         41 . A lighting device as recited in  claim 36 , wherein said reflective element is mounted on a second portion of said thermal conduction element. 
     
     
         42 . A lighting device as recited in  claim 36 , wherein a second reflective element is positioned on said thermal conduction element. 
     
     
         43 . A lighting device as recited in  claim 36 , further comprising at least one battery and circuitry selectively connecting said battery electrically to at least one of said solid state light emitters. 
     
     
         44 . A lighting device, comprising:
 at least one thermal conduction element, said thermal conduction element having a first side and a second side, said first side of said thermal conduction element comprising at least a first surface, said thermal conduction element defining at least one conduction element opening;   a plurality of solid state light emitters mounted on said first side of said thermal conduction element;   at least one reflective element, said reflective element also being mounted on said first side of said thermal conduction element; and   at least one shield member, said shield member extending from said first side of said thermal conduction element away from said second side of said thermal conduction element.   
     
     
         45 . A lighting device as recited in  claim 44 , wherein said thermal conduction element is annular. 
     
     
         46 . A lighting device as recited in  claim 44 , wherein said conduction element opening is covered by a light transmitting plate, so that light which is emitted by any of said solid state light emitters and which passes through said conduction element opening must pass through said light transmitting plate. 
     
     
         47 . A lighting device as recited in  claim 44 , wherein at least one of said solid state light emitters is an LED. 
     
     
         48 . A lighting device as recited in  claim 44 , wherein said thermal conduction element surrounds said conduction element opening. 
     
     
         49 . A lighting device as recited in  claim 44 , wherein said first side is a first surface and said second side comprises a second surface, and said first surface and said second surface are substantially parallel to each other and are spaced from each other by a distance which is not greater than 10% of the maximum distance between any two points on said second surface. 
     
     
         50 . A lighting device as recited in  claim 49 , wherein said thermal conduction element is annular. 
     
     
         51 . A lighting device as recited in  claim 48 , wherein said first surface comprises only a portion of said first side. 
     
     
         52 . A lighting device as recited in  claim 51 , wherein said second surface comprises only a portion of said second side. 
     
     
         53 . A lighting device as recited in  claim 51 , wherein said second surface comprises an entirety of said second side. 
     
     
         54 . A lighting device as recited in  claim 51 , wherein said second surface comprises only a portion of said second side. 
     
     
         55 . A lighting device as recited in  claim 51 , wherein said first surface comprises an entirety of said first side. 
     
     
         56 . A lighting device as recited in  claim 55 , wherein said second surface comprises only a portion of said second side. 
     
     
         57 . A lighting device as recited in  claim 51 , wherein said second surface comprises an entirety of said second side. 
     
     
         58 . A lighting device as recited in  claim 44 , wherein said second surface comprises an entirety of said second side. 
     
     
         59 . A lighting device as recited in  claim 36 , wherein the plurality of solid state emitters comprise multiple LED light sources for emitting multiple, different spectral characteristics of light. 
     
     
         60 . A lighting device as recited in  claim 59 , wherein the first reflective element is diffusely reflective and forms an optical integrating cavity for combining light from the LED light sources. 
     
     
         61 . A lighting device as recited in  claim 60 , further comprising a control circuit for controlling the LED light sources to provide a predetermined characteristic in the combined light for output from the lighting device. 
     
     
         62 - 65 . (canceled) 
     
     
         66 . A lighting device, comprising:
 at least one thermal conduction element;   a plurality of solid state light emitters;   at least first and second reflective elements, wherein:   said solid state light emitters are mounted on at least a first portion of said thermal conduction element and said first reflective element is positioned such that at least a portion of light emitted from at least one of said solid state light emitters is reflected by said first reflective element, and   said second reflective element is positioned on said thermal conduction element.   
     
     
         67 . A lighting device as recited in  claim 66 , wherein the plurality of solid state emitters comprise multiple LED light sources for emitting multiple, different spectral characteristics of light. 
     
     
         68 . A lighting device as recited in  claim 67 , wherein the first reflective element is diffusely reflective and forms an optical integrating cavity for combining light from the LED light sources. 
     
     
         69 . A lighting device as recited in  claim 68 , further comprising a control circuit for controlling the LED light sources to provide a predetermined characteristic in the combined light for output from the lighting device. 
     
     
         70 - 73 . (canceled) 
     
     
         74 . A lighting device as recited in  claim 44 , wherein the plurality of solid state emitters comprise multiple LED light sources for emitting multiple, different spectral characteristics of light. 
     
     
         75 . A lighting device as recited in  claim 74 , wherein the first reflective element is diffusely reflective and forms an optical integrating cavity for combining light from the LED light sources. 
     
     
         76 . A lighting device as recited in  claim 75 , further comprising a control circuit for controlling the LED light sources to provide a predetermined characteristic in the combined light for output from the lighting device. 
     
     
         77 - 80 . (canceled) 
     
     
         81 . A lighting device as recited in  claim 60 , wherein the first reflective element is highly diffusely reflective to energy in the visible, near-infrared, and ultraviolet wavelengths. 
     
     
         82 . A lighting device as recited in  claim 81 , wherein the first reflective element comprises diffusely reflective plastic material. 
     
     
         83 . A lighting device as recited in  claim 60 , wherein the first reflective element comprises a rigid substrate having an interior surface, and a diffusely reflective coating layer formed on the interior surface of the rigid substrate. 
     
     
         84 . A lighting device as recited in  claim 83 , wherein the diffusely reflective coating layer is a flat-white paint including a zinc-oxide based pigment mixed with an alkali metal silicate vehicle-binder. 
     
     
         85 . A lighting device as recited in  claim 68 , wherein the first reflective element is highly diffusely reflective to energy in the visible, near-infrared, and ultraviolet wavelengths. 
     
     
         86 . A lighting device as recited in  claim 85 , wherein the first reflective element comprises diffusely reflective plastic material. 
     
     
         87 . A lighting device as recited in  claim 68 , wherein the first reflective element comprises a rigid substrate having an interior surface, and a diffusely reflective coating layer formed on the interior surface of the rigid substrate. 
     
     
         88 . A lighting device as recited in  claim 87 , wherein the diffusely reflective coating layer is a flat-white paint including a zinc-oxide based pigment mixed with an alkali metal silicate vehicle-binder. 
     
     
         89 . A lighting device as recited in  claim 75 , wherein the first reflective element is highly diffusely reflective to energy in the visible, near-infrared, and ultraviolet wavelengths. 
     
     
         90 . A lighting device as recited in  claim 89 , wherein the first reflective element comprises diffusely reflective plastic material. 
     
     
         91 . A lighting device as recited in  claim 75 , wherein the first reflective element comprises a rigid substrate having an interior surface, and a diffusely reflective coating layer formed on the interior surface of the rigid substrate. 
     
     
         92 . A lighting device as recited in  claim 91 , wherein the diffusely reflective coating layer is a flat-white paint including a zinc-oxide based pigment mixed with an alkali metal silicate vehicle-binder.