Patent ID: 8477094
Filing Date: 2013-07-02
Classification: G09G,G11C

Abstract:
1. A shift register comprising: a plurality of stages, which includes a (n−3)-th (where n is a positive integer) stage to a (n+3)-th stage, supplied with gate shift clocks that are sequentially delayed, a forward gate start pulse, a reverse gate start pulse, a carry signal, a gate high voltage, and a gate low voltage lower than the gate high voltage, and connected to each other in cascade, wherein the n-th stage, supplied with a (n−1)-th gate shift clock, an n-th gate shift clock, and a (n+1)-th gate shift clock, includes: a scan pulse output unit configured to output an n-th scan pulse depending on a voltage at a Q node via a first output node; a carry signal output unit configured to output an n-th carry signal depending on a voltage at the Q node via a second output node separated from the first output node; and a shift direction changing switch circuit configured to charge the Q node in response to a (n−3)-th carry signal output from the (n−3)-th stage, in a forward shift mode where the forward gate start pulse is generated, and, to charge the Q node in response to a (n+3)-th carry signal output from the (n+3)-th stage, in a reverse shift mode where the reverse gate start pulse is generated, wherein the n-th stage further comprises a Q node voltage maintaining switch circuit configured to charge the Q node in response to the (n−1)-th gate shift clock in the forward shift mode, and to charge the Q node in response to the (n+1)-th gate shift clock in the reverse shift mode.