Patent ID: 7499063

Claim:
A liquid crystal display comprising: a liquid crystal panel having a large number of picture elements arranged at intersections of plural selection lines and data lines; a selection line signal output IC for outputting a selection line signal to the selection lines of said liquid crystal panel; a reference voltage generator circuit, which comprises first resistors connected in series between two voltages and second resistors connected in series to said first resistors, generates plural reference voltages from respective connection points of the first resistors, switches over the reference voltage either to an image display voltage or to a black display voltage, and outputs the switched reference voltage to plural wiring lines connected to the connection points; and a signal line drive IC, to which an image data signal and the reference voltage are inputted, and which outputs a voltage based on the reference voltage and the image data signal, to a data line of the liquid crystal panel, wherein the reference voltage generator circuit has a switch section which is opened and closed by a black voltage selection signal, and the switch section has first switching element arranged in parallel to the first resistors so as to open and close between a connection point for generating a black voltage and a connection point for generating a white voltage among the plural image display voltages, and second switching element which is arranged so as to control resistance values of the second resistors and output value of which has opposite polarity to output value of the first switching element, and outputs a black display voltage to the plural wiring lines by turning the first switching element into closed states, and turning the second switching element into opened states, on the basis of the black voltage selection signal to short-circuit between the connection points and to change resistance values of the second resistors, and the signal line drive IC outputs a black write voltage to the data line on the basis of the black display voltage, and the switch section includes an image display period for supplying said image display voltage and a black display period for supplying the black display voltage in one horizontal period, and is switched over by the black voltage selection signal, so as to be synchronized with a change of a selection line signal in a row of the selection line for writing an image therein and a row thereof for writing black therein.