Patent ID: 7012591

Claim:
An apparatus for converting a digital pixel signal to a gamma voltage signal for enabling a pixel for a display color in a liquid crystal display (LCD), the display color of the pixel being one of a group of colors, wherein the digital pixel signal corresponds to the pixel, the gamma voltage signal is for application to the pixel for displaying the display color with an intensity according to the gamma voltage signal, and a plurality of pixels of the LCD for displaying the respective colors reach respective maximum luminances at respective maximum gamma voltages for the respective colors, the apparatus comprising: a pixel signal converting unit for converting the digital pixel signal to a converted pixel signal, wherein the relation between the digital pixel signal and the converted pixel signal is determined according to the display color of the pixel, the magnitude of the converted pixel signal has a range determined according to the display color of the pixel, the range of magnitude of the converted pixel signal with respect to the display color of the pixel depends on the maximum gamma voltage at which the pixel reaches the maximum luminance with respect to the display color of the pixel, and the maximum gamma voltages for the group of colors are not all the same; and a gamma correction unit coupled to the pixel signal converting unit for converting the converted pixel signal into the gamma voltage signal and outputting the gamma voltage signal, wherein when the converted pixel signal indicates a maximum value in the range of magnitude with respect to the display color of the pixel, the gamma voltage signal is the maximum gamma voltage at which the pixel reaches maximum luminance with respect to the display color of the pixel.