Patent ID: 6961038

Claim:
A color liquid crystal display device comprising: a liquid crystal display part; light sources for irradiating the liquid crystal display part with lights of three primary colors sequentially or simultaneously, the device displaying a frame picture by sequential fields of three primary color pictures and a field of a white picture in the liquid crystal display part; a circuit for determining a minimum level of brightness among three color signals in a pixel; a circuit for subtracting the minimum level from the level of brightness of the three primary color signals to create display signals for respective primary color fields; a circuit for determining a maximum among minimum levels of brightness of all pixels in a frame and multiplying the minimum levels of each pixel by a constant to create a display signal in the white field, the constant being determined by the maximum and a weight factor of the white field relative to the primary color fields; and a circuit for modulating the brightness of primary color light sources in the white field according to the constant, wherein the constant is automatically set depending on changes of displayed information.