Tuning of emitter with multiple LEDs to a single color bin
First Claim
1. A method for tuning a color produced by a lamp having a plurality of light emitting diodes (LEDs) including at least three groups of LEDs wherein each group of LEDs produces light having a different color and wherein a current applied to each group of LEDs is independently variable, the method comprising:
- defining a target color;
identifying, based on the target color, a first tuned color intermediate between a first color of light produced by a first one of the groups of LEDs and a second color of light produced by a second one of the groups of LEDs;
identifying a second tuned color intermediate between the first tuned color and a third color of light produced by the third group of LEDs, the second tuned color being closer than the first tuned color to the target color;
determining, based at least in part on one or more measurements of light produced by the lamp while current is supplied only to the first group of LEDs and the second group of LEDs, a first distribution of a total current between the first group of LEDs and the second group of LEDs that produces light having the first tuned color, the first distribution of the total current defining a target current ratio;
determining, based at least in part on one or more measurements of light produced by the lamp while holding the target current ratio constant, a second distribution of the total current between the first and second groups of LEDs combined and the third group of LEDs that produces light having the second tuned color.
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Abstract
The color of an LED-based lamp can be tuned to a desired color or color temperature. The lamp can include two or more independently addressable groups of LEDs associated with different colors or color temperatures and a total-internal-reflection (TIR) color-mixing lens to produce light of a uniform color by mixing the light from the different groups of LEDs. The color of the output light is tuned by controllably dividing an input current among the groups of LEDs. Tuning can be performed once, e.g., during manufacture, and the lamp does not require active feedback components for maintaining color temperature.
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Citations
20 Claims
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1. A method for tuning a color produced by a lamp having a plurality of light emitting diodes (LEDs) including at least three groups of LEDs wherein each group of LEDs produces light having a different color and wherein a current applied to each group of LEDs is independently variable, the method comprising:
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defining a target color; identifying, based on the target color, a first tuned color intermediate between a first color of light produced by a first one of the groups of LEDs and a second color of light produced by a second one of the groups of LEDs; identifying a second tuned color intermediate between the first tuned color and a third color of light produced by the third group of LEDs, the second tuned color being closer than the first tuned color to the target color; determining, based at least in part on one or more measurements of light produced by the lamp while current is supplied only to the first group of LEDs and the second group of LEDs, a first distribution of a total current between the first group of LEDs and the second group of LEDs that produces light having the first tuned color, the first distribution of the total current defining a target current ratio; determining, based at least in part on one or more measurements of light produced by the lamp while holding the target current ratio constant, a second distribution of the total current between the first and second groups of LEDs combined and the third group of LEDs that produces light having the second tuned color. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for tuning a color produced by a lamp having a plurality of light emitting diodes (LEDs) including at least four groups of LEDs wherein each group of LEDs produces light having a different color and wherein a current applied to each group of LEDs is independently variable, the method comprising:
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defining a target color; identifying, based on the target color, a first tuned color intermediate between a first color of light produced by a first one of the groups of LEDs and a second color of light produced by a second one of the groups of LEDs; determining, based at least in part on one or more measurements of light produced by the lamp while current is supplied only to the first group of LEDs and the second group of LEDs, a first distribution of a total current between the first group of LEDs and the second group of LEDs that produces light having the first tuned color, the first distribution of the total current defining a target current ratio; selecting, based on the first tuned color, one of the groups of LEDs other than the first and second groups as a supplemental group of LEDs, the selection based on comparing the first tuned color and the target color; identifying a second tuned color intermediate between the first tuned color and a third color of light produced by the supplemental group of LEDs, the second tuned color being closer than the first tuned color to the target color; and determining, based at least in part on one or more measurements of light produced by the lamp while holding the target current ratio constant, a second distribution of the total current between the first and second groups of LEDs combined and the supplemental group of LEDs that produces light having the second tuned color. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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Specification