Patent ID: 6950098

Claim:
A system for real time correction of light output and/or colour of an image displayed on a display device ( 1 ), the system comprising: a display device ( 1 ) comprising an active display area ( 6 ) for displaying the image, an image forming device ( 2 ) and an electronic driving system ( 4 ) for driving the image forming device ( 2 ), an optical sensor unit ( 10 ) comprising an optical aperture ( 21 ) and a light sensor ( 22 ) having an optical axis, to make optical measurements on a light output from a representative part of the active display area ( 6 ) of the image forming device ( 2 ) and generating optical measurement signals ( 11 ) therefrom, a feedback system ( 12 ) receiving the optical measurement signals ( 11 ) and on the basis thereof controlling the electronic driving system ( 4 ), wherein the optical aperture ( 21 ) of the optical sensor unit ( 10 ) has an acceptance angle such that at least 50%, alternatively 60%, alternatively 70%, alternatively 75% of the light received by the light sensor ( 22 ) comes from light travelling within 15° of the optical axis of the light sensor ( 22 ).