Rules for efficient light sources using phosphor converted LEDs
First Claim
1. A light emitting device comprising an LED and at least one phosphor materials, wherein a first phosphor material with a decay time of less than about 3 ms is positioned close to the LED and a second phosphor material with a relatively slower decay time is positioned relatively further from the LED, and wherein for each phosphor material, the product of (incident LED flux)×
- (excitation cross-section of the phosphor)×
(phosphor material decay time) is less than 0.3.
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Accused Products
Abstract
An LED lamp including an LED and one or more phosphors, wherein for each phosphor, a figure of merit (FOM) defined as the product of (incident LED flux)×(excitation cross-section of the phosphor)×(phosphor material decay time) is less than 0.3. Such an arrangement provides a light emitting device with improved lumen output and color stability over a range of drive currents.
10 Citations
14 Claims
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1. A light emitting device comprising an LED and at least one phosphor materials, wherein a first phosphor material with a decay time of less than about 3 ms is positioned close to the LED and a second phosphor material with a relatively slower decay time is positioned relatively further from the LED, and wherein for each phosphor material, the product of (incident LED flux)×
- (excitation cross-section of the phosphor)×
(phosphor material decay time) is less than 0.3. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
- (excitation cross-section of the phosphor)×
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14. A method for producing a phosphor conversion LED lamp, the method comprising the steps of providing an LED chip and subsequently depositing at least one phosphor material over the LED chip, wherein a first phosphor material with a decay time of less than about 3 ms is positioned close to the LED and a second phosphor material with a relatively slower decay time is positioned relatively further from the LED, and wherein the phosphor materials are selected and deposited such that for each phosphor material, the product of (incident LED flux)×
- (excitation cross-section of the phosphor)×
(phosphor material decay time) is less than 0.3.
- (excitation cross-section of the phosphor)×
Specification