Patent ID: 7949085

Claim:
A shift register, comprising: n register units electrically coupled in cascade, where n is equal to or greater than 3, each register unit outputting an output pulse according to a first clock signal, a second clock signal, and an input pulse, wherein the input pulse of a first one of the n register units comprises a start trigger pulse, and wherein the input pulse of the second to the n th register units comprises the output pulse of a preceding one of the first to the (n−1) th register units, respectively, each register unit comprising: a first switch unit for conducting the input pulse to a first node when the first switch unit is turned on; a second switch unit for conducting the first clock signal to an output end to generate the output pulse when the second switch unit is turned on in response to the input pulse; a third switch unit for conducting a supply voltage to the output end when the second switch unit is turned off; a fourth switch unit, electrically coupled to a supply end, for conducting the supply voltage to the first node when the fourth switch unit is turned on in response to a driving pulse; and a driving unit for providing the driving pulse according to the first clock signal, the second clock signal, and the input pulse, the driving unit comprising: a first subtract circuit for producing a first modulation signal according to the second clock signal and the input pulse; a second subtract circuit for producing a second modulation signal according to the first clock signal and the output pulse; a sixth switch unit electrically connected to the first subtract circuit for conducting the input pulse to a third node when the sixth switch unit is turned on; a seventh switch unit electrically connected to the third node for conducting the first modulation signal to a second node to generate the driving pulse when the seventh switch unit is turned on; an eighth switch unit electrically coupled to the supply end and the second node, for conducting the supply voltage to the second node when the seventh switch unit is turned off; and a ninth switch unit electrically coupled to the supply end and the third node, for conducting the supply voltage to the third node when the ninth switch unit is turned on according to the second modulation signal.