Patent ID: 7675500

Claim:
A method of illuminating a backlit display having a light source illuminating a plurality of display pixels and comprising a plurality of light-emitting elements each capable of emitting light at respective intensities independent of other ones of said light emitting elements, said method comprising: (a) spatially varying the luminance of said light source by: (i) filtering an intensity value signal for a plurality of input image pixels and sampling the filtered said signal at respective spatial coordinate areas, each corresponding to at least one of said light-emitting elements; and (ii) spatially varying the luminance of said light source by driving at least two of said light-emitting elements independently of each other according to a nonlinear relationship between the sampled said luminance signal at a respective said spatial coordinate area and the driven luminance of said at least one of said light-emitting elements; (b) varying the transmittance of a light valve of said display in a non-binary manner; and (c) rescaling a sample of said filtered intensity value to reflect said nonlinear relationship.