Patent ID: 7868557

Claim:
A method for controlling an arrangement of light emitting semiconductors, which include semiconductors emitting light of substantially distinct colors, comprising: providing target intensities and a target intensity ratio of emitted light of different colors; controlling the semiconductors dependent on a semiconductor junction temperature for each color, whereby the junction temperatures are determined by a measured temperature in the system; controlling the semiconductors dependent on light output feedback of emitted light for each color to achieve a total light emission which is identical to a reference total light emission, wherein the steps of temperature dependent controlling and the light output dependent controlling are carried out with different first and second intervals, of which the second interval is more than a thousand times longer than the first interval during continuous light emission by the semiconductors, and, wherein, for each distinct color, the temperature dependent controlling is adjusted dependent on a ratio of a light output reference value and a light output feedback value, which is determined with said second intervals.