Patent ID: 9304367
Filing Date: 2016-04-05
CPC Classification: G02F,H01L,H02H

Claim Text:
1. An electro-static discharge protection circuit for a liquid crystal display, wherein the liquid crystal display is provided with a signal line, a low level signal line and a high level signal line, and the electro-static discharge protection circuit comprises: a first thin film transistor, wherein a drain/source electrode and a source/drain electrode of the first thin film transistor are respectively connected to the signal line and the low level signal line; a second thin film transistor, wherein a drain/source electrode and a source/drain electrode of the second thin film transistor are respectively connected to the signal line and the high level signal line; a third thin film transistor, wherein a drain/source electrode and a source/drain electrode of the third thin film transistor are respectively connected to the signal line and the low level signal line, and a high level signal is provided to a gate electrode of the third thin film transistor; and a fourth thin film transistor, wherein a drain/source electrode and a source/drain electrode of the fourth thin film transistor are respectively connected to the signal line and the high level signal line, and a low level signal is provided to a gate electrode of the fourth thin film transistor, wherein when positive electro-static charges are generated on the signal line, a voltage corresponding to the positive electro-static charges is higher than a voltage of the high level signal line, a thin film transistor with a gate electrode connected to the high level signal line is switched on, and the positive electro-static charges are discharged through the switched on thin film transistor, and when negative electro-static charges are generated on the signal line, a voltage corresponding to the negative electro-static charges is lower than a voltage of the low level signal line, a thin film transistor with a gate electrode connected to the low level signal line is switched on, and the negative electro-static charges are discharged through the switched on thin film transistor.