Methods For Generating Melatonin-Response-Tuned White Light With High Color Rendering

Abstract

The present disclosure provides methods for generating tunable white light with controllable circadian energy performance. The methods use a plurality of LED to generate light with color points that fall within blue, yellow/green, red, and cyan color ranges, with each LED being driven with a separately controllable drive current in order to tune the generated light output. Different light emitting modes can be selected that utilize different combinations of the plurality of LED in order to tune the generated white light.

1 . A method of generating white light, the method comprising:
 producing light from a first light emitting diode (“LED”) that comprises a blue LED with peak wavelength of between about 405 nm and about 470 nm;   producing light from a second LED that comprises a blue LED with peak wavelength of between about 405 nm and about 470 nm;   producing light from a third LED that comprises a blue LED with peak wavelength of between about 405 nm and about 470 nm, a fourth LED that comprises a cyan LED with peak wavelength of between about 485 nm and about 520 nm; and   passing the light produced by each of the first, second, third, and fourth LED through one of a plurality of respective luminophoric mediums;   wherein the light produced by the second LED generates a red color point after passing through one of the plurality of respective luminophoric mediums;   wherein spectral power distribution for the wavelengths of red color point includes at least between 8.7% to 20.5% for 541 nm to 580 nm, between 48.5% and 102.8% for 581 nm to 620 nm, 100% for between 621 nm to 660 nm, between 1.8% to 74.3% for 661 nm to 700 nm, between 0.5% to 29.5% for 701 nm to 740 nm; and   combining the light exiting the plurality of respective luminophoric mediums together into the white light;   wherein the white light corresponds to at least one of a plurality of points along a predefined path near the black body locus in the 1931 CIE Chromaticity Diagram.