Patent ID: 8718225
Filing Date: 2014-05-06
Classification: G11C

Abstract:
1. A shift register comprising a plurality of stages for sequentially outputting scan pulses in such a manner that high durations of the scan pulses partially overlap with each other, wherein each of the stages comprises: a node controller configured to control a charging duration of a set node; and an output unit configured to output a corresponding one of the scan pulses through an output terminal for the charging duration of the set node, wherein: the node controller maintains the charging duration for a time corresponding to a low duration of any one of a plurality of clock pulses having phase differences therebetween; and the output unit outputs the corresponding scan pulse of a high state for the charging duration by selectively outputting a first charging voltage for the charging duration, the first charging voltage being a direct current (DC) voltage, wherein the plurality of clock pulses are sequentially output in such a manner that low durations thereof partially overlap with each other, wherein the output unit comprises a pull-up switching device controlled by a voltage at the set node and connected between a first charging voltage line transferring the first charging voltage and the output terminal, wherein the output unit further comprises a pull-down switching device controlled by any one of the clock pulses and connected between the output terminal and a first discharging voltage line transferring a first discharging voltage, wherein the node controller of an nth one of the stages (where n is a natural number) comprises: a first switching device controlled by any one of the clock pulses and connected between the output terminal of an (n−p)th one of the stages (where p is a natural number less than n) and a first preset node; a second switching device controlled by any one of the clock pulses and connected between a second preset node and a second discharging voltage line transferring a second discharging voltage; a third switching device controlled by any one of the clock pulses and connected between the set node and the second discharging voltage line; a fourth switching device controlled by a voltage at the first preset node and connected between a third charging voltage line transferring a third charging voltage and the second preset node; and a fifth switching device controlled by a voltage at the second preset node and connected between a second charging voltage line transferring a second charging voltage and the set node, wherein the first switching device, the second switching device, the third switching device and the pull-down switching device are all supplied with the same clock pulse, wherein the clock pulse supplied to the first switching device, the second switching device, the third switching device and the pull-down switching device has a low duration coinciding with a high duration of a scan pulse output from the nth stage, and wherein the clock pulse supplied to the first switching device, the second switching device, the third switching device and the pull-down switching device has a high duration partially overlapping with a high duration of a scan pulse from the (n−p)th stage.