Patent ID: 7443369

Claim:
A liquid crystal display device: storage means in which gradation voltage value data is stored; display control means in which gradation voltage value data read out from the storage means or gradation voltage value data based on external control signals is inputted; gradation voltage setting means which sets gradation voltages based on gradation voltage value data received from the display control means; driver means to which gradation voltages set by the gradation voltage setting means are inputted; and a liquid crystal panel which is driven in response to gradation voltages selected by the driver means, wherein writing of the gradation voltage value data to the storage means signals inputted to terminals of the display control means, such signals being inputted from outside the display control means; a brightness measuring unit which measures a brightness of the liquid crystal display device, and outputs a brightness data of the liquid crystal display device; and a personal computer which receives the brightness data from the brightness measuring unit; and wherein the personal computer determines whether the gradation voltage is within a predetermined range or not based on the brightness data, and generates the alternative gradation voltage value data, and outputs the alternative gradation voltage value data to the display control means when the gradation voltage is out of the predetermined range.