LED illumination device with layered phosphor pattern
AssigneeLumination LLC
InventorsAnant Achyut Setlur, Joseph John Shiang, Alok Mani Srivastava, Holly Ann Comanzo, Stanton Earl Weaver, Charles Adrian Becker
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Abstract
A method of applying at least two phosphors to an LED, wherein a first phosphor material having a lower absorption, shorter luminescence decay time, and/or lower thermal quenching than a second phosphor material is positioned closer to the LED than the second phosphor. Such an arrangement provides a light emitting device with improved lumen output and color stability over a range of drive currents.
Claims20
A method of forming a light emitting device comprising depositing a first phosphor material over a semiconductor light emitter and depositing a second phosphor material over said first phosphor material, such that said first phosphor material is closer to said semiconductor light emitter than said second phosphor material, wherein said first phosphor material has at least one of a shorter decay time and a lower absorption of radiation from said semiconductor light emitter than said second phosphor material.
A method of forming a light emitting device comprising depositing a first phosphor material over a semiconductor light emitter and depositing a second phosphor material over said first phosphor material, such that the first phosphor material is closer to said semiconductor light emitter than said second phosphor material, wherein said first phosphor material has reduced thermal quenching than said second phosphor material.
Dependencies are inferred from the claim text.