Color controlled light source and a method for controlling color generation in a light source

Abstract

This invention relates to a color controlled light source comprising a plurality of colored light elements, and a plurality of (filtered) photo detectors, having different spectral characteristics covering all or most of the total spectrum of the light elements. The (filtered) photo detectors detect the light output of the light source, and generate corresponding detection signals. The light source further has a color control unit for generating driving signals to the light elements on the basis of the detection signals and a predetermined target color point of the light output of the light source, and a modulator for individual signature modulation of the driving signal to each one of said light elements. A corresponding demodulator is provided for demodulation of the detection signals and extraction, from each detection signal, of actual values of the light outputs of the light elements. The color control unit has means for determining the spectral output of each light element on basis of the actual values, means for determining an actual color point from said spectral outputs of all light elements, and means for comparing said target color point with said actual color point and, if there is a difference, adjusting said driving signals in order to minimize the difference.