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

A color controlled light source comprising:

• a plurality of colored light elements;
• a plurality of photo detectors, whose spectral characteristics are different and together at least substantially cover the total spectrum of said light elements, which photo detectors detect the light output of the light source, and generate corresponding detection signals;
• a color control unit for generating driving signals to said light elements on the basis of said detection signals and a predetermined target color point of the light output of the light source,
• a modulator for individual signature modulation of the driving signal to each one of said light elements;
• and
• a demodulator for individual signature demodulation of said detection signals and extraction, from each detection signal, of each actual value of the light output of each one of said light elements;
• wherein said color control unit is configured to determine the spectral output of each light element on the basis of said actual values, to determine an actual color point of the light output of the light source from the spectral outputs of all light elements, and to compare the target color point of the light output of the light source with the actual color point of the light output of the light source and, if there is a difference, to adjust the driving signals in order to minimize the difference,
• wherein determining the spectral output of each light element comprises determining said spectral output by means of an algorithm for asymmetric function modeling of the spectral output of a light element.