Step-wise intensity control of a solid state lighting system
First Claim
1. A lighting system, comprising:
- a first solid state light emitting element for emitting a color of light;
a second solid state light emitting element for emitting the same color of light emitted from the first solid state light emitting element;
an optical processing element coupled to receive light emitted from the first and second solid state light emitting elements, for processing the received light to produce a virtual source of light of said color at a luminous output area of the lighting system; and
a control circuit connected to the first and second solid state light emitting elements, wherein the control circuit is configured to implement functions, including functions to;
(a) drive each of the first and second solid state light emitting elements to operate at a respective predetermined level; and
(b) selectively activate and deactivate function (a) with respect to the first and second solid state light emitting elements to selectively switch the first and second solid state light emitting elements to and from said respective predetermined levels, in combinations to provide a plurality of discrete intensity levels for the virtual source of light of said color at the luminous output area of the lighting system.
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Accused Products
Abstract
A solid state lighting system controls overall light output level in a step-wise manner by discretely controlling the ON/OFF state of its light emitters. Solid state emitters that are ON at a given time are set and kept at a level intended to produce a desired output characteristic, e.g. at a level to produce a described color of light. The system utilizes optical processing of the generated light, for example by diffuse reflection in an optical integrating cavity, sufficient to convert the point source output(s) from the emitting elements into a uniform virtual source output. The virtual source output appears uniform regardless of how many emitters are ON or OFF, and only the perceptible intensity of the light output changes with the number of emitters that the system has ON.
31 Citations
24 Claims
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1. A lighting system, comprising:
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a first solid state light emitting element for emitting a color of light; a second solid state light emitting element for emitting the same color of light emitted from the first solid state light emitting element; an optical processing element coupled to receive light emitted from the first and second solid state light emitting elements, for processing the received light to produce a virtual source of light of said color at a luminous output area of the lighting system; and a control circuit connected to the first and second solid state light emitting elements, wherein the control circuit is configured to implement functions, including functions to; (a) drive each of the first and second solid state light emitting elements to operate at a respective predetermined level; and (b) selectively activate and deactivate function (a) with respect to the first and second solid state light emitting elements to selectively switch the first and second solid state light emitting elements to and from said respective predetermined levels, in combinations to provide a plurality of discrete intensity levels for the virtual source of light of said color at the luminous output area of the lighting system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. In a solid state lighting system comprising a first solid state light emitting element for emitting a color of light and a second solid state light emitting element for emitting the same color of light as the first solid state light emitting element, a method of controlling intensity of light output from the system, the method including steps comprising:
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receiving a first input representing a first desired brightness level; in response to the first input, activating the first solid state light emitting element to emit light of a color at a predetermined intensity level for the first solid state light emitting element by turning a current to the first solid state light emitting element ON, while maintaining the second solid state light emitting element in a deactivated state by keeping current to the second solid state light emitting element OFF; diffusely processing light emitted from the first solid state light emitting element to produce a virtual source of light of said color at a luminous output area of the lighting system, corresponding in intensity to the first desired brightness level; receiving a second input representing a second desired brightness level higher than the first desired brightness level; in response to the second input, activating the first solid state light emitting element to emit light of the color at the predetermined intensity level for the first solid state light emitting element and activating the second solid state light emitting element to emit light of the color at a predetermined intensity level for the second solid state light emitting element by turning a current to each of the respective solid state light emitting elements ON; and diffusely processing light emitted from the first and second solid state light emitting elements to produce a virtual source of light of said color at the luminous output area of the lighting system corresponding in intensity to the second desired brightness level. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
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Specification