Patent ID: 9672784
Date: 2017-06-06
CPC Classifications: G09G,G11C

Claim:
1. A CMOS gate driving circuit, comprising a plurality of shift register units which are cascade connected, and n is set to be a positive integer, and except the shift register units of the first stage and the last stage, the shift register unit of the nth stage comprises: a forward-backward scan module, a latch module electrically coupled to the forward-backward scan module and an output module electrically coupled to the latch module; the forward-backward scan module comprises: a first module and a second module, and the first module is a transmission module in forward scan and a pull-down module in backward scan; the second module is a pull-down module in forward scan and a transmission module in backward scan; the first module comprises: a first NAND gate, and two input ends of the first NAND gate are electrically coupled to a forward scan voltage level signal and a stage transfer signal outputted by the shift register unit of the former stage, respectively, and an output end is electrically coupled to a third node; a first N-type thin film transistor, and a gate of the first N-type thin film transistor is electrically coupled to a scan voltage signal outputted by the shift register unit of the former stage, and a source is electrically coupled to the third node, and a drain is electrically coupled to a first node; the second module comprises: a second NAND gate, and two input ends of the second NAND gate are electrically coupled to a backward scan voltage level signal and a stage transfer signal outputted by the shift register unit of the latter stage, respectively, and an output end is electrically coupled to a fourth node; a second N-type thin film transistor, and a gate of the second N-type thin film transistor is electrically coupled to a scan voltage signal outputted by the shift register unit of the latter stage, and a source is electrically coupled to the fourth node, and a drain is electrically coupled to the first node; in forward scan, the forward scan voltage level signal is high voltage level, and the backward scan voltage level signal is low voltage level; in backward scan, the forward scan voltage level signal is low voltage level, and the backward scan voltage level signal is high voltage level.