Liquid crystal display device with a control mechanism for eliminating images
AssigneeHannstar Display Corp.
InventorsWen-Chen Fang, Chun-Chin Tseng, Wen-Zhe Lin, Pei-Chi Tsai
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Abstract
The present invention discloses a liquid crystal display device and a control method thereof. In the present invention, a clock controller detects an external clock signal and outputs a switching signal according to the external clock signal. According the information carried by the switching signal, a shutoff switching circuit controls a gamma voltage generator and a common voltage circuit to output voltages making a pixel electrode and a common electrode have a zero voltage difference. Thereby, the pixel charges are completely released after system shutoff, and the shutoff retained images are instantly eliminated.
Claims18
A liquid crystal display device comprising:
- a gamma voltage generator;
- a common voltage circuit;
- a clock controller detecting an external clock signal and outputting a switching signal based on the detection result of the external clock signal;
- a power converter coupled to said clock controller and providing a first working voltage for said clock controller;
- a shutoff switching circuit coupled to said clock controller, receiving a second working voltage from said power converter, receiving said switching signal, and outputting one of a first control voltage and a second control voltage to the gamma voltage generator and the common voltage circuit according to information carried by said switching signal, to control a reference voltage output by the gamma voltage generator and a common voltage output by the common voltage circuit, making a pixel electrode and a common electrode of a pixel has a zero voltage difference when the clock controller does not detect said external clock signal or when the clock controller detects said external clock signal is abnormal;
- and
- said shutoff switching circuit not controlling said power converter.
Dependencies are inferred from the claim text.