# US 8,772,691 B2 · Optical integrating cavity lighting system using multiple LED light sources > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,772,691 B2 - Document ID: US8772691B2 - Status: Granted - Kind: B2 - Application number: 12/762,001 - Filed: 2010-04-16 - Published: 2010-08-12 - Granted: 2014-07-08 - Earliest claimed: 2003-06-23 - Assignees: ABL IP Holding LLC - Applicants: Donald F. May; Jack C. Rains, Jr. - Inventors: Donald F. May; Jack C. Rains, Jr. - Web page: https://patentgrep.com/patent/US8772691B2 ## CPC - F21K 9/60: Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction - F21K 9/62: using mixing chambers, e.g. housings with reflective walls - G01J 3/0254: {Spectrometers, other than colorimeters, making use of an integrating sphere} - G01J 3/10: Arrangements of light sources specially adapted for spectrometry or colorimetry - F21Y 2115/10: Light-emitting diodes [LED] - G01J 3/0264: {Electrical interface; User interface} - G01J 3/501: {Colorimeters using spectrally-selective light sources, e.g. LEDs} - F21K: NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR - G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N) - F21Y: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED ## 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. ## Claims ### Claim 1 A lighting device, comprising: at least one thermal conduction element; a plurality of solid state light emitters, wherein the plurality of solid state light emitters comprise multiple LED light sources for emitting multiple, different spectral characteristics of light; at least a first reflective element, wherein the first reflective element is white, highly diffusely reflective and forms an optical integrating cavity for combining light from the LED light sources; at least one conical deflector having a specular reflective inner surface coupled to an output aperture of the optical integrating cavity; a control circuit for controlling the LED light sources to provide a predetermined characteristic in the combined light for output from the lighting device; and a sensor for sensing a parameter during operation of the lighting device, wherein the control by the control circuit is responsive to the parameter sensed by the sensor, 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. ### Claim 2 (depends on 1) A lighting device as recited in claim 1, wherein the sensor comprises a temperature sensor. ### Claim 3 (depends on 1) A lighting device as recited in claim 1, wherein the sensor comprises a light intensity sensor. ### Claim 4 (depends on 1) A lighting device as recited in claim 1, wherein the sensor comprises a color sensor. ### Claim 5 A lighting device, comprising: at least one thermal conduction element; a plurality of solid state light emitters, wherein the plurality of solid state light emitters comprise multiple LED light sources for emitting multiple, different spectral characteristics of light; at least first and second reflective elements, wherein the first reflective element is white, highly diffusely reflective and forms an optical integrating cavity for combining light from the LED light sources; at least one conical deflector having a specular reflective inner surface coupled to an output aperture of the optical integrating cavity; a control circuit for controlling the LED light sources to provide a predetermined characteristic in the combined light for output from the lighting device; and a sensor for sensing a parameter during operation of the lighting device, wherein the control by the control circuit is responsive to the parameter sensed by the sensor, 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. ### Claim 6 (depends on 5) A lighting device as recited in claim 5, wherein the sensor comprises a temperature sensor. ### Claim 7 (depends on 5) A lighting device as recited in claim 5, wherein the sensor comprises a light intensity sensor. ### Claim 8 (depends on 5) A lighting device as recited in claim 5, wherein the sensor comprises a color sensor. ### Claim 9 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, wherein the plurality of solid state emitters comprise multiple LED light sources for emitting multiple, different spectral characteristics of light; at least one reflective element, said reflective element also being mounted on said first side of said thermal conduction element, wherein the first reflective element is white, highly diffusely reflective and forms an optical integrating cavity for combining light from the LED light sources; at least one conical deflector having specular reflective inner surface coupled to an output aperture of the optical integrating cavity; 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; a control circuit for controlling the LED light sources to provide a predetermined characteristic in the combined light for output from the lighting device; and a sensor for sensing a parameter during operation of the lighting device, wherein the control by the control circuit is responsive to the parameter sensed by the sensor. ### Claim 10 (depends on 9) A lighting device as recited in claim 9, wherein the sensor comprises a temperature sensor. ### Claim 11 (depends on 9) A lighting device as recited in claim 9, wherein the sensor comprises a light intensity sensor. ### Claim 12 (depends on 9) A lighting device as recited in claim 9, wherein the sensor comprises a color sensor. ### Claim 13 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, wherein the plurality of solid state emitters comprise multiple LED light sources for emitting multiple, different spectral characteristics of light; at least one reflective element, said reflective element also being mounted on said first side of said thermal conduction element, wherein the first reflective element is white, highly diffusely reflective and forms an optical integrating cavity for combining light from the LED light sources, wherein the one conduction element opening forms a passageway through which the optically integrated light is emitted from the cavity; 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; a control circuit for controlling the LED light sources to provide a predetermined characteristic in the combined light for output from the lighting devices; and a sensor for sensing a parameter during operation of the lighting device, wherein the control by the control circuit is responsive to the parameter sensed by the sensor. ### Claim 14 (depends on 13) A lighting device as recited in claim 13, wherein the passageway formed by the one conduction element opening allows output of optically integrated light but precludes direct viewing of the LED light sources.