Patent ID: 7253797

Claim:
A liquid crystal display device comprising: an analog voltage signal generator storing an input synchronous signal and storing a plurality of data values, which represent a plurality of input digital data signals in response to a write enable signal, said analog voltage signal generator also converting stored digital data signals into a plurality of different analog voltage signal pairs in response to an output enable signal; a plurality of reference voltage generators for dividing a boosted source voltage according to the analog voltage signal pairs from the analog voltage signal generator to generate a plurality of reference voltages; and a source driver circuit for receiving the plurality of reference voltages from the plurality of reference voltage generators, wherein a digital/analog converter of the analog voltage signal generator changes a reference voltage value and outputs a changed value reference voltage to the reference voltage generators, to thereby change a contrast ratio according to changed reference voltage values when a command to change a reference voltage value is transferred to the digital/analog converter.