Circadian-friendly LED light source
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.
1. A light source comprising:
at least one first solid-state light emitting device emitting a first light having a peak in a range 420 to 430 nm, and one or more radiation sources for emitting second light of one or more wavelengths;
wherein said light source is configured in at least a first way to emit a first emitted light comprising at least a portion of said first light and said second light, the first emitted light being substantially white light characterized by a first spectral power distribution (SPD), a first CCT, and a first chromaticity; and
wherein the power of said first SPD in the range of 400 to 440 nm is more than 8% of the power of said first SPD in the range of 380 to 850 nm, said CCT is in a range of about 2500° to about 5000° K, and said chromaticity is within +/− five Du′v′ points of a Planckian locus when calculated with the 1964 CIE color matching functions.
2. The light source of claim 1 , wherein said first emitted light has a color rendering index Ra above 80.
3. The light source of claim 1 , wherein said first emitted light has a color rendering index R9 above 80.
4. The light source of claim 1 , wherein said radiation sources are color-converting materials excited by said first light.
5. The light source of claim 1 , further comprising at least one second solid-state light-emitting device emitting a third light having a peak in a range 440 to 500 nm.
6. The light source of claim 5 , configured in a second way to emit a second emitted light comprising at least a portion of said third, the second emitted light being substantially white light characterized by a second spectral power distribution (SPD), wherein the power of said second SPD in the range of 440 to 500 nm is more than 10% of the power of said first SPD in the range of 380 to 850 nm.
7. The light source of claim 6 , further comprising circuitry to selectively drive said first and second at least one solid state light emitting devices to selectively emit said first and second emitted light.
8. The light source of claim 1 , wherein the at least one first solid-state light emitter is one of: an LED, a laser diode, an OLED.
9. A method of configuring a light source based on the age of a user, said method comprising:
configuring one or more solid-state light emitting devices (LEDs) and one or more radiation sources, wherein at least one of said one or more LEDs emits a first light having a peak in a range 405 to 430 nm, and said one or more radiation sources emit a second light of one or more wavelengths, said one or more LEDs and said one or more radiation sources being configured such that said light source emits at least one emitted light, said at least one emitted light being characterized by an SPD in the range of 380 to 850 nm, a violet SPD in the range of 400 to 440 nm, and a blue SPD in the range of 440 to 500 nm, and said at least one emitted light having a chromaticity within +/− five Du′v′ points of a Planckian locus based on CIE color matching functions for said age of said user; and
wherein said at least one emitted light comprises a first emitted light comprising at least a portion of said first light and said second light, wherein the power of said blue SPD is less than 5% of the power of said SPD.
10. The method of claim 9 , wherein the power of said violet SPD is greater than 8% of the power of said SPD in said first emitted light.
11. The method of claim 9 , wherein the power of said blue SPD is less than 1% of the power of said SPD in said first emitted light.
12. The method of claim 9 , wherein said first emitted light has a color rendering index Ra above 80.
13. The method of claim 9 , wherein said first emitted light has a color rendering index R9 above 80.
14. The method of claim 9 , wherein said radiation sources are color-converting materials excited by said first light.
15. The method of claim 9 , wherein at least one of said one or more LEDs emits a third light having a peak in a range 440 to 500 nm.
16. The method of claim 15 , wherein said at least one emitted light comprises a second emitted light comprising at least a portion of said third light, said second emitted light being substantially white light and wherein the power of said blue SPD is more than 10% of the power of said SPD.
17. The method of claim 16 , further comprising circuitry to selectively power said one or more LEDs to selectively emit said first or second emitted light.
18. The method of claim 9 , further comprising determining a temperature of the light source.