Patent ID: 8120276
Filing Date: 2012-02-21
Classification: H05B,Y02B

Abstract:
1. A method for controlling the color locus of a light source ( 10 ) emitting mixed-colored light containing light of at least two different colors which is emitted by a plurality of primary light sources comprising: dividing the primary light sources into groups, determining and controlling the brightness values of the primary light sources within a group separately according to colors, such that the color locus of the mixed-colored light lies in a predetermined region of the CIE Standard chromaticity diagram, wherein the brightness values of the primary light sources are determined and controlled by: setting the brightness of the primary light source using pulse-width-modulated signals which are switched on with a fixed basic period for a specific length of time; phase-shifting the first switch-on time of the primary light source of a first color relative to the switch-on time of the remaining colors such that only the primary light sources of the first color are switched-on during a first time interval, wherein the phase-shifting of the first switch-on time of the primary light source of a first color is distributed over a plurality of basic periods, the plurality of basic periods continuing until the beginning of the first switch-on time is substantially congruent with the beginning of the first time interval; and at least partially overlapping the switch-on times of all of the primary light sources of the light source in a second time interval which is adjacent to the first time interval.