Patent ID: 6342897
Filing Date: 2002-01-29
Classification: G09G,H04N

Abstract:
A method of compensating for the non-uniform color appearance of a color display that is due to the variations of primary colors of the light sources which are called the original primaries, comprising the steps of:measuring the chromaticity coordinates and the maximum luminous intensity of every original primary in every pixel of the display, wherein the maximum luminous intensity is not the maximum producible luminous intensity of the original primary but the luminous intensity under rating operating current or voltage and the term â€œluminous intensityâ€  is the luminous intensity averaged over the interval of a time slot when the output light of the original primary is pulse-width modulated; choosing a set of virtual primaries, which are characterized by chromaticity coordinates and the maximum luminous intensities, from the measured data of all the original primaries so that the tristimulus values of each virtual primary can be produced by the original primaries in every pixel of the display, in which the chosen virtual primaries can be effectively used as the light sources in stead of the original primaries and the color appearance of the display can be made to be uniform because the virtual primaries are the same for all pixels of the display; finding the relation between video signals and modified video signals which are the input signals of light sources so that the tristimulus values of the original primaries in a pixel of the display are equal or close to the tristimulus values of the virtual primaries, wherein the tristimulus values of the original primaries can be set to be not exactly equal to the tristimulus values of the virtual primaries, if the deviations are small enough so that the non-uniformity of the displayed color can be tolerated; calculating conversion coefficients; converting video signals into modified video signals; generating the driving signals of the original primaries of the display from the modified video signals.