Shift register, liquid crystal display device having the shift register and method of driving scan lines using the same

摘要

In a bi-directional shift register and a liquid crystal display device having the bi-directional shift register, the shift register further includes a dummy stage for resetting a last stage. The dummy stage is reset by a control signal of the last stage or by the output signal of the dummy stage. Therefore, power consumption and layout area may be reduced. The shift register includes a plurality of stages and two dummy stages, and two selection signals for selecting shift direction is applied to each of the stages.

主权项

1. A method of driving a plurality of scan lines by providing a display panel with a plurality of scan line driving signals from a gate driver including a shift register, the method comprising:
receiving a scan start signal to generate a first scan line driving signal and lowering a voltage level of the first scan line driving signal so as to inactivate a first scan line in response to a second scan line driving signal; receiving one of previous scan line driving signals to generate an Nth scan line driving signal for activating an Nth scan line, N being a natural number in a range from two to a number of scan lines except for a last scan line; lowering a voltage level of the Nth scan line driving signal so as to inactivate the Nth scan line in response to one of next scan line driving signals; generating a last scan line driving signal from a last stage in response to one of previous scan line driving signals of the last scan line driving signal; generating a dummy output signal from a dummy stage in response to the last scan line driving signal; lowering a voltage level of the last scan line driving signal so as to inactivate the last scan line in response to the dummy output signal; and directly applying the scan start signal to the dummy stage to lower a fourth voltage level of the dummy output signal in response to the scan start signal.