Patent ID: 7061226

Claim:
A method to detect one or a plurality of defective pixels in a spatial light modulator, comprising the actions of: providing an electromagnetic radiation source to illuminate said spatial light modulator, arranging a reference pattern in said spatial light modulator, illuminating said spatial light modulator, determining a position of a reference pixel in said spatial light modulator by detecting a relayed image of said reference pattern in a detector arrangement, arranging a first pattern in said spatial light modulator, wherein features in an area of the first pattern are too small and closely spaced to be individually resolved by the detector arrangement, illuminating said spatial light modulator, detecting a relayed image of said first pattern in said detector arrangement, arranging at least a second pattern in said spatial light modulator, illuminating said spatial light modulator, detecting a relayed image of said at least a second pattern in said spatial light modulator analyzing said relayed images of said first pattern and said at least a second pattern to detect differences between said images and theoretical images thereof.