Patent ID: 8188962
Filing Date: 2012-05-29
Classification: G09G

Abstract:
1. A liquid crystal display, comprising: a liquid crystal panel comprising a plurality of pixel units; a scanning circuit configured to activate the pixel units; a power supply circuit comprising: a control unit configured to generate a control signal in response to an external command when the liquid crystal display is switched off; a logic converter comprising a logic AND gate, a first logic NOT gate, and a second logic NOT gate, the logic AND gate comprising a first input terminal configured to receive the external command directly, a second input terminal configured to receive the corresponding control signal via the first logic NOT gate, an output terminal configured to output a first logic calculation result according to the external command and the corresponding control signal, and provide the first logic calculation result to the second logic NOT gate, the second logic NOT gate configured to receive the first logic calculation result, and convert the first logic calculation result into a second logic calculation result; a voltage level shifter directly connected to the second logic NOT gate for receiving the second logic calculation result, and the voltage level shifter configured to adjust a voltage level of the second logic calculation result to generate an output enable signal; and an output control circuit comprising a first transistor, a second transistor, a first resistor, and an output terminal, the first transistor comprising a gate electrode configured to receive the output enable signal from the voltage level shifter, a drain electrode configured to receive an analog power voltage, and a source electrode connected to the output terminal, the second transistor comprising a gate electrode configure to receive the corresponding control signal from the control unit, a drain electrode connected to the drain electrode of the first transistor and the output terminal, and a source electrode connected to ground via the first resistor, and the output control circuit configured to output the analog power voltage to the scanning circuit according to both the control signal and the output enable signal; wherein the scanning circuit drives all the pixel units to discharge in response to the analog power voltage such that an image displayed by the liquid crystal panel is removed.