Patent ID: 6262829
Filing Date: 2001-07-17
Classification: G09G,H04N

Abstract:
A method of digital grayscale control using light source modulation, the method comprising:providing a light valve including a spatial light modulator with at least one pixel;providing grayscale data that indicates desired grayscale level for the pixel during a frame period;providing a light source configured to illuminate the pixel, the light source generating light with increasing intensity for a rise-time after electric power to the light source is substantially increased and generating light with decreasing intensity for a decay-time after electric power to the light source is substantially reduced;measuring response of the light source;increasing substantially the electric power to the light source;reducing substantially the electric power to the light source;dividing the frame period into at least four time slices with independent durations, the durations being varied as a function of the measured response so that each time slice has a binary weighted value; andindependently setting a pixel to one of an 0 state and an 1 state during each of the at least four time slices of the frame period based on the grayscale data.