Systems for displaying images utilizing two clock signals

A system for displaying images comprising:

• a display device comprising:
• a signal driving circuit comprising a plurality of PMOS shift registers connected in series and controlled only by a first clock signal and a second clock signal, wherein the PMOS shift registers are operative to output corresponding driving pulses in turn after receiving a start pulse;
• wherein the corresponding driving pulse output from an Nth register of the PMOS shift registers is output to an N+1th register of the PMOS shift registers and serves as a corresponding start pulse of the N+1th register of the PMOS shift registers, the Nth register of the PMOS shift registers outputs a corresponding driving pulse based on the first clock signal responsive to receiving a corresponding driving pulse from an N−1th register of the PMOS shift registers, and the N+1th register of the PMOS shift registers outputs a corresponding driving pulse based on the second clock signal responsive to receiving a corresponding driving pulse from the Nth register of the PMOS shift registers, and the PMOS shift registers each comprise:
• a control unit comprising:
• a first switch element having a first connecting terminal coupled to one of the first and second clock signals, a second connecting terminal, and a control terminal coupled to a first node;
• a second switch element having a first connecting terminal coupled to the second connecting terminal of the first switch element, a second connecting terminal coupled to a supply voltage, and a control terminal coupled to a second node;
• a third switch element having a first connecting terminal coupled to the other of the first and second clock signals, a second connecting terminal coupled to the second node, and a control terminal coupled to the first connecting terminal thereof;
• a fourth switch element having a first connecting terminal coupled to the start pulse or the corresponding start pulse, a second connecting terminal coupled to the first node, and a control terminal coupled to the first connecting terminal thereof;
• a fifth switch element having a first connecting terminal coupled to the second node, a second connecting terminal coupled to the supply voltage, and a control terminal coupled to the first connecting terminal of the fourth switch element;
• and
• a sixth switch element having a first connecting terminal coupled to the first node, a second connecting terminal coupled to the supply voltage, and a control terminal coupled to the first connecting terminal of the fifth switch element;
• wherein the control unit is operative to generate first and second control signals at the first and second nodes respectively in response to receiving the start pulse or the corresponding start pulse;
• a buffering unit comprising a control terminal coupled to the first clock signal or the second clock signal, and the buffing unit being operative to output the coupled clock signal to serve as the corresponding driving pulse, according to the first and second control signals, wherein the corresponding driving pulse output from the buffer unit in the Nth register of the PMOS shift registers is output to the control unit in the N+1th register of the PMOS shift registers and serves as the corresponding start pulse of the N+1th register of the PMOS shift register;
• and
• a display element coupled to the signal driving circuit, wherein the display element is driven by the signal driving circuit, wherein each of the first through sixth switch elements comprises a first PMOS transistor connected in series with a second PMOS transistor, and first terminals of the first and second PMOS transistors are coupled together, gates of which are coupled together to serve as the control terminal, and second terminals of the first and second PMOS transistors serve as the first and second connecting terminals respectively.