Patent ID: 8253719

Claim:
A liquid crystal display device comprising: a first pumping unit that first pumps a high-potential power source voltage applied; a second pumping unit that generates a gate high voltage by pumping the high-potential power source voltage first pumped in the first pumping unit; a voltage detecting unit for detecting a level of a D.C. power source voltage applied, comparing the detected level of the D.C. power source voltage with a preset reference voltage level, and outputting a low voltage or high voltage according to the comparison result, wherein the voltage detecting unit outputs the high voltage when the level of voltage detected is higher than the preset reference voltage level and outputs the low voltage when the level of voltage detected is lower than the preset reference voltage level; a inverter for inverting the low voltage or high voltage output from the voltage detecting unit; a level shifter that shifts the high voltage inverted from the inverter to a level corresponding to that of the gate high voltage from the second pumping unit, and supplies the gate high voltage to a discharging circuit through a discharging line, wherein the discharging circuit includes a plurality of discharging parts and input sides of the discharging parts are connected to the discharging line in common and output sides of the discharging parts are connected in one-to-one correspondence with gate lines; and a delay device, connected between input and output sides of the second pumping unit, that maintains the gate high voltage output from the level shifter for a preset period of time, wherein the discharging parts discharge through data lines remaining charges from pixels connected to the gate line by supplying the gate high voltage from the level shifter to the gate line.