Patent ID: 7173384

Claim:
An illumination device which emits mixed-color light during operation, said light containing light of at least two different color channels (R, R 1 , G, G 1 , B, B 1 ), comprising: at least one first primary light source ( 1 ) of a first color, the light of which forms a first color channel (R, R 1 , G, G 1 , B, B 1 ); at least one second primary light source ( 1 ) of a second color, the light of which forms a second color channel (R, R 1 , G, G 1 , B, B 1 ); at least one sensor device ( 3 ), which is positioned to receive mixed-color light and is suitable for detecting brightness of light of a continuous wavelength range comprising the first and second color channels (R, R 1 , G, G 1 , B, B 1 ) and which determines brightness values of the first and second color channels (R, R 1 , G, G 1 , B, B 1 ) separately and repeatedly during operation; and an evaluation and control device ( 4 ), which, during operation, evaluates the brightness values of the first and second color channels (R, R 1 , G, G 1 , B, B 1 ) and determines pulse-width-modulated electrical signals with a basic period ( 11 ) modified in such a way for the driving of the first and second color channels (R, R 1 , G, G 1 , B, B 1 ) that color location of the mixed-color light lies within a predetermined region of the CIE standard chromaticity diagram.