Bidirectional shift register

摘要

Disclosed herein is a bidirectional shift register which is capable of preventing multi-outputs from both end stages. The shift register includes a plurality of stages for outputting scan pulses forward or reversely based on a start pulse and a plurality of clock pulses with a phase difference. A last one of the stages includes a forward scan controller for making a set node active and a reset node inactive based on any one of the clock pulses and a scan pulse from an upstream stage, a reverse scan controller for making the set node active and the reset node inactive based on any one of the clock pulses and the start pulse, and an output unit for outputting any one of a corresponding scan pulse and a deactivation voltage based on a voltage at the set node, a voltage at the reset node and any one of the clock pulses.

主权项

1. A bidirectional shift register comprising a plurality of stages for outputting scan pulses forward or reversely based on a start pulse and a plurality of clock pulses with a phase difference, the bidirectional shift register further comprising a start selector for supplying the start pulse to only a first one of the stages in a forward mode where the bidirectional shift register outputs the scan pulses forward, and to only a last one of the stages in a reverse mode where the bidirectional shift register outputs the scan pulses reversely,
wherein the first stage outputs a corresponding one of the scan pulses first of all in the forward mode, wherein the last stage outputs a corresponding one of the scan pulses first of all in the reverse mode, wherein the first stage comprises:
a forward scan controller configured to make a set node active and a reset node inactive based on any one of the clock pulses and the start pulse from the forward selection switching device;a reverse scan controller configured to make the set node active and the reset node inactive based on any one of the clock pulses and a scan pulse from a downstream stage; and an output unit configured to output any one of the corresponding scan pulse and a deactivation voltage based on a voltage at the set node and a voltage at the reset node.