| 摘要 |
PURPOSE:To reduce mounting terminals, and form a simple wiring structure by connecting two signal input parts of a bidirectional shift register circuit to each other, and arranging switching gates having mutually reversed polarity just before both initial stage shift registers. CONSTITUTION:Both signal input parts of a bidirectional shift register circuit are connected to each other, and a signal inputted from a common signal input terminal 11 is transmitted to both signal input parts 111 and 112. In an optional shift mode, a clock gate which has the same polarity with a clock gate to perform operation to transmit or cut off an input signal according to a signal DIR or the like to determine the shift direction and is arranged just before an initial stage shift register, transmits either one side signal in conformity with the optional shift mode, and cuts off an opposite side signal in unconformity with a shift mode. That is, when the signal DIR is put in high electric potential and the other signal is put in low electric potential, a clock gate just before the input part 111 transmits the input signal, and a gate just before the input part 112 cuts off the input signal. |
