Patent ID: 7071669
Filing Date: 2006-07-04
Classification: G09G

Abstract:
1. A reference voltage generation circuit which generates multi-valued reference voltages for generating a gamma-corrected grayscale value based on grayscale data, the reference voltage generation circuit comprising: a first resistance ladder circuit having at least one variable resistance circuit in which a resistance value between both ends is variable, and outputting multi-valued voltages; a second resistance ladder circuit in which a plurality of resistance circuits each having a fixed resistance value are connected in series, outputting a plurality of voltages; and a third resistance ladder circuit having at least one variable resistance circuit in which a resistance value between both ends is variable, and outputting multi-valued voltages, wherein the first to third resistance ladder circuits are connected in series between first and second power supply lines to which first and second power supply voltages are respectively supplied; and wherein the resistance values of the variable resistance circuits in the first and third resistance ladder circuits are variably controlled according to a given command setting or a given variable control signal.