Methods of providing tunable warm white light

Abstract

The present disclosure provides methods for generating tunable white light. The methods include using a plurality of LED strings to generate light with color points that fall within white, red, and yellow/green color ranges, with each LED string being driven with a separately controllable drive current in order to tune the generated light output.

1 . A method of generating white light, the method comprising:
 passing the light produced by each of a first, second, and third LED strings through one of a plurality of respective luminophoric mediums to produce a first unsaturated light, a second unsaturated light, and a third unsaturated light, respectively;   combining the first unsaturated light, the second unsaturated light, and the third unsaturated light together into the fourth unsaturated light;   producing the fourth unsaturated light output which corresponds to at least one of a plurality of points along a predefined path near a black body locus in the 1931 CIF Chromaticity Diagram within a 7-step NilacAdain ellipse around any point on the black body locus having a correlated color temperature between about 1800K and about 3200K; and,   wherein the second unsaturated light has spectral power distribution including at least spectral power intensities of 1.4% and 12.2% for wavelengths between 501-540 nm, between 8.7% and 24.7% for wavelengths between 541-580 nm, between 48.5% and 102.8% for wavelengths between 581-62.0 nm, between 1.8% and 74.3% for wavelengths between 661-700 nm, between 0.5% and 29.5% for wavelengths between 701-740 nm, and between 0.3% and 9% for wavelengths between 741-780 nm, relative to the normalized range for wavelengths between 621-660 nm with a value of 100.0%.