Circadian-friendly LED light sources

Patent metadata

Field	Value
Publication number	US-9915775-B2
Application number	US-201614996143-A
Country	US
Kind code	B2
Filing date	Jan 14, 2016
Priority date	Aug 29, 2013
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80.

First claim

What is claimed is:

1. A light-emitting system comprising:
at least one solid-state lighting emitter emitting with a peak between 400 and 430 nm;
at least one first phosphor having a peak emission between 500 nm and 550 nm, and at least one second phosphor having a peak emission between 600 nm and 670 nm; and
wherein said lighting emitter and said first and second phosphors are configured such that the light-emitting system emits an emitted light having a spectral power distribution (SPD), wherein the SPD has a local minimum in a spectral region between 440 am and 480 am and wherein an area under the SPD in the range of 440 nm to 480 am is less than 2% of an area under the SPD in a range of 380 nm to 780 nm.

2. The system of claim 1 , wherein said first and second phosphors are selected from silicates, fluorosilicates doped with Eu 2+ , chalcogenides doped with Eu 2+ , nitridosilicates, oxynitridosilicates, oxynitridoaluminosilicates, β-sialons doped with Eu 2+ carbidooxynitridosilicates doped with Eu 2+ , nitridosilicates doped with Eu 2+ ; carbidonitridosilicates doped at least with Eu 2+ ; chalcogenides doped with Eu 2+ , oxides, oxyfluorides, complex fluorides doped with Mn 4+ , and combinations thereof.

3. The system of claim 1 , wherein said emitted light has a certain correlated color temperature (CCT), is configured to produce a predetermined illuminance of about 50 lux to about 5000 lux, and a circadian stimulation no greater than about 50% of a reference circadian stimulation of a reference illuminant configured to produce an illuminance essentially the same as said predetermined illuminance and having a CCT the same as said certain CCT.

4. The system of claim 3 , wherein said certain CCT is greater than or equal to 2700K.

5. The system of claim 1 , wherein the area under the SPD within a range of 440 nm and 480 nm is less than 0.5% of the area under the SPD within a range of 380 nm to 780 nm.

6. The system of claim 1 , wherein an absolute distance from the Planckian locus (Duv) is less than 0.006.

7. The system of claim 1 , wherein the system comprises a general CRI index (Ra) is greater than or equal to 80.

8. The system of claim 1 , wherein the system comprises a special CRI index #9 (R9) greater than or equal to 0.

9. The system of claim 1 , further comprising a filter substantially absorbing or reflecting light having a wavelength within a range of 430 nm to 490 nm.

10. The system of claim 9 , wherein the filter does not significantly affect a chromaticity of the emitted light.

11. The system of claim 1 , wherein the first phosphor and the second phosphor are disposed in layers or in a pattern of small patches around the LED pump.

Assignees

• Soraa Inc

Inventors

• Krames Michael R
• David Aurelien J F
• Radkov Emil
• Smitt Willem

Classifications

• H05B45/20

  Controlling the colour of the light · CPC title

• H05B47/16

  by timing means · CPC title

• F21W2107/10

  for land vehicles · CPC title

• F21Y2115/10

  Light-emitting diodes [LED] · CPC title

• F21S4/20

  with light sources held by or within elongate supports · CPC title