US Patent No. 10,602,583

SYSTEMS FOR PROVIDING TUNABLE WHITE LIGHT WITH HIGH COLOR RENDERING


Patent No. 10,602,583
Issue Date March 24, 2020
Title Systems For Providing Tunable White Light With High Color Rendering
Inventorship Raghuram L. V. Petluri, Los Angeles, CA (US)
Paul Kenneth Pickard, Los Angeles, CA (US)
Assignee Ecosense Lighting Inc., Los Angeles, CA (US)

Claim of US Patent No. 10,602,583

5. A semiconductor light emitting device, comprising:a first light emitting diode (“LED”) string that comprises a first LED that has a first recipient luminophoric medium that comprises a first luminescent material, wherein the first LED and first luminophoric medium together emit a first unsaturated light having a first spectral power distribution having spectral power distribution intensity of between 27.0 and 65.1 for the wavelength range of 501 nm to 600 nm, between 24.8 and 46.4 for the wavelength range of 601 nm to 700 nm, and between 1.1 and 6.8 for the wavelength range of 701 nm to 780 nm, relative to a value of 100.0 for the wavelength range of 380 nm to 500 nm;
a second LED string that comprises a second LED that has a second recipient luminophoric medium that comprises a second luminescent material, wherein the second LED and second luminophoric medium together emit a second unsaturated light having a second spectral power distribution having spectral power distribution intensity of between 3.3 and 17.4 for the wavelength range of 380 nm to 500 nm, between 8.9 and 24.8 for the wavelength range of 501 nm to 600 nm, and between 1.1 and 18.1 for the wavelength range of 701 nm to 780 nm, relative to a value of 100.0 for the wavelength range of 601 nm to 700 nm;
a third LED string that comprises a third LED that has a third recipient luminophoric medium that comprises a third luminescent material, wherein the third LED and third luminophoric medium together emit a third unsaturated light having a third spectral power distribution having spectral power distribution intensity of between 2.4 and 35.8 for the wavelength range of 380 nm to 500 nm, between 61.2 and 142.0 for the wavelength range of 601 nm to 700 nm, and between 7.9 and 21.1 for the wavelength range of 701 nm to 780 nm, relative to a value of 100.0 for the wavelength range of 501 nm to 600 nm;
a fourth LED string that comprises a fourth LED that has a fourth recipient luminophoric medium that comprises a fourth luminescent material, wherein the fourth LED and fourth luminophoric medium together emit a fourth unsaturated light having a fourth spectral power distribution having spectral power distribution intensity of between 19.9 and 32.2 for the wavelength range of 380 nm to 500 nm, between 14.7 and 42.4 for the wavelength range of 601 nm to 700 nm, and between 1.3 and 6.1 for the wavelength range of 701 nm to 780 nm, relative to a value of 100.0 for the wavelength range of 501 nm to 600 nm; and
a drive circuit configured to adjust the relative values of first, second, third, and fourth drive currents provided to the LEDs in the first, second, third, and fourth LED strings, respectively, to adjust a fifth color point of a fifth unsaturated light that results from a combination of the first, second, third, and fourth unsaturated light.