Temperature responsive control for lighting apparatus including light emitting devices providing different chromaticities and related methods
First Claim
1. A lighting apparatus comprising:
- a plurality of light emitting devices including a first light emitting device configured to emit light having a first chromaticity, a second light emitting device configured to emit light having a second chromaticity different than the first chromaticity, and a third light emitting device configured to emit light having the second chromaticity;
a temperature sensor configured to generate a temperature sense signal responsive to heat generated by at least one of the plurality of light emitting devices; and
a compensation circuit coupled to the third light emitting device wherein the compensation circuit is configured to vary a level of electrical current through the third light emitting device relative to an electrical current through the first and second light emitting devices responsive to the temperature sense signal.
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Accused Products
Abstract
A lighting apparatus may include a plurality of light emitting devices, a temperature sensor, and a compensation circuit. The plurality of light emitting devices may include a first light emitting device configured to emit light having a first chromaticity, a second light emitting device configured to emit light having a second chromaticity different than the first chromaticity, and a third light emitting device configured to emit light having the second chromaticity. Moreover, the first, second, and third light emitting devices may be electrically coupled in series. The temperature sensor may be configured to generate a temperature sense signal responsive to heat generated by at least one of the plurality of light emitting devices. The compensation circuit may be coupled to the third light emitting device, with the compensation circuit being configured to vary a level of electrical current through the third light emitting device relative to the electrical current through the first and second light emitting devices responsive to the temperature sense signal. Related methods are also discussed.
411 Citations
32 Claims
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1. A lighting apparatus comprising:
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a plurality of light emitting devices including a first light emitting device configured to emit light having a first chromaticity, a second light emitting device configured to emit light having a second chromaticity different than the first chromaticity, and a third light emitting device configured to emit light having the second chromaticity; a temperature sensor configured to generate a temperature sense signal responsive to heat generated by at least one of the plurality of light emitting devices; and a compensation circuit coupled to the third light emitting device wherein the compensation circuit is configured to vary a level of electrical current through the third light emitting device relative to an electrical current through the first and second light emitting devices responsive to the temperature sense signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A lighting apparatus comprising:
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a plurality of light emitting devices including a first light emitting device configured to emit light having a first chromaticity and a second light emitting device configured to emit light having a second chromaticity different than the first chromaticity, wherein the plurality of light emitting devices are oriented to combine the light emitted thereby to provide a combined optical output; a temperature sensor configured to generate a temperature sense signal responsive to heat generated by at least one of the plurality of light emitting devices; and a compensation circuit coupled to the second light emitting device, wherein the compensation circuit is configured to vary an electrical current passing through the second light emitting device responsive to the temperature sense signal, wherein the compensation circuit is configured to set a first level of current passing through the second light emitting device so that the combined optical output has a first color point responsive to a first temperature sense signal representing a first temperature, and wherein the compensation circuit is configured to set a second level of current passing through the second light emitting device different than the first level so that the combined optical output has a second color point different than the first color point responsive to a second temperature sense signal representing a second temperature greater than the first temperature wherein the first color point is redder than the second color point. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A method of operating a lighting apparatus including a plurality of light emitting devices including a first light emitting device configured to emit light having a first chromaticity, a second light emitting device configured to emit light having a second chromaticity different than the first chromaticity, and a third light emitting device configured to emit light having the second chromaticity, the method comprising:
varying a level of electrical current through the third light emitting device relative to the electrical current through the first and second light emitting devices responsive to a temperature of the lighting apparatus, wherein the first light emitting device is configured to emit light having the first chromaticity, and wherein the second and third light emitting devices are configured to emit light having the second chromaticity different than the first chromaticity. - View Dependent Claims (25, 28, 29, 30, 31)
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26. A method of operating a lighting apparatus including a plurality of light emitting devices including a first light emitting device configured to emit light having a first chromaticity and a second light emitting device configured to emit light having a second chromaticity different than the first chromaticity, wherein the plurality of light emitting devices are oriented to combine the light emitted thereby to provide a combined optical output, the method comprising:
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setting a first level of current passing through the second light emitting device so that the combined optical output has a first color point responsive to a first temperature of the lighting apparatus; and setting a second level of current passing through the second light emitting device different than the first level so that the combined optical output has a second color point responsive to a second temperature of the lighting apparatus greater than the first temperature, wherein the first color point is redder than the second color point. - View Dependent Claims (27, 32)
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Specification