US Patent 7088478 Chromaticity conversion device and chromaticity conversion method

Linear chromaticity conversion is used to perform color reproduction of a liquid crystal display (LCD) compatible with a cathode ray tube (CRT). An inputted signal is subjected to processing similar to processing used in the CRT display. A light source chromaticity conversion processing portion carries out a γ correction to the signal in a γ operation portion by using γ1=γcrt of the same nonlinear characteristics as the CRT, and performs an operation of a chromaticity conversion matrix in a matrix operation portion. An LCD inverse γ correction portion uses γ2 establishing γ_lcd=γlcd/γ2=1 to perform an inverse γ correction to the inputted signal. An LCD γ characteristic operation portion performs a γ correction using γ characteristics of the LCD to the signal inputted from the LCD inverse γ correction portion, outputs a picture signal, and causes an image to be displayed on the LCD.