Patent ID: 6989809

Claim:
A liquid crystal display, comprising: a plurality of converters that convert a luminance signal and two color-difference signals of an input video signal into digital signals, each digital signal corresponding to one of the luminance and color-difference signals; a plurality of setting circuits that set magnitudes of reference voltage ranges to determine upper limit voltages and lower limit voltages of the digital signals to be identical in each of the converters, each setting circuit including: a variable power supply connected to one of the converters, the variable power supply to determine the upper limit voltage that defines a maximum value of the input signal to said one of the converters corresponding to a maximum value of the digital signal outputted from said one of the converters, the variable power supply to permit a contrast adjustment of picture images, and a second power supply connected to said one of the converters, the second power supply to determine the lower limit voltage that defines a minimum value of the input signal to said one of the converters corresponding to a minimum value of the digital signal outputted from said one of the converters; and a plurality of intermediate voltage circuits that set intermediate voltages between the upper limit voltages and the lower limit voltages, the intermediate voltage circuits to input the intermediate voltages into the converters corresponding to said two color-difference signals.