Patent ID: 7081890

Claim:
A bi-directional driving circuit of a flat panel display device having a plurality of blocks driven by a start pulse, first to fourth clock signals of different phases, and first and second power source voltages, each block comprising: a shift register comprising, a first control part applying either the start pulse or an output signal of a previous block to a first node according to one of the first to fourth clock signals or a signal at the second node, a second control part controlling the second node according to the start pulse, either the output signal of the previous block or an output signal of the next block, and one of the first to fourth clock signals, a third control part applying either the start pulse or the output signal of the next block to the first node according to either one of the first to fourth clock signals or a signal at the second node, and a buffer outputting one of the first to fourth clock signals as a shift pulse according to the first and second nodes; and a level shifter shifting a level of the shift pulse output from the shift register in each block, and outputting the shifted level.