06441558 is referenced by 435 patents.

An LED luminary system for providing power to LED light sources to generate a desired light color comprises a power supply stage configured to provide a DC current signal. A light mixing circuit is coupled to said power supply stage and includes a plurality of LED light sources with red, green and blue colors to produce various desired lights with desired color temperatures. A controller system is coupled to the power supply stage and is configured to provide control signals to the power supply stage so as to maintain the DC current signal at a desired level for maintaining the desired light output. The controller system is further configured to estimate lumen output fractions associated with the LED light sources based on junction temperature of the LED light sources and chromaticity coordinates of the desired light to be generated at the light mixing circuit. The light mixing circuit further comprises a temperature sensor for measuring the temperature associated with the LED light sources and a light detector for measuring lumen output level of light generated by the LED light sources. Based on the temperatures measured, the controller system determines the amount of output lumen that each of the LED light sources need to generate in order to achieve the desired mixed light output, and the light detector in conjunction with a feedback loop maintains the required lumen output for each of the LED light sources.

Title
White LED luminary light control system
Application Number
9/732197
Publication Number
6441558 (B1)
Application Date
December 7, 2000
Publication Date
August 27, 2002
Inventor
Gert Bruning
Sleepy Hollow
NY, US
Chin Chang
Yorktown Heights
NY, US
Subramanian Muthu
Tarrytown
NY, US
Assignee
Koninklijke Philips Electronics
US
IPC
H05B 37/02
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