Bi-directional shift register useful as scanning registers for active matrix displays and solid state image pick-up devices

摘要

A bi-directional shift register capable of transferring bit data in either a forward or reverse direction. The shift register includes multiple transfer elements (e.g., flip-flop circuits) cascaded together which provide synchronous transfer of the bit data from one stage to an adjacent stage in either direction. The shift register further includes two switching circuits for electrically connecting an input terminal of one transfer element to an output terminal of the adjacent transfer element. The first switching circuit is enabled to cause the transfer of the bit data in the forward direction, and the second switching circuit is enabled to cause the transfer of the bit data in the reverse direction.