A two-phase drive bipolar linear image sensor using zigzag arrangement of PCD shift register elements

A bipolar linear image sensor composed of a 512-bit photodiode array, two 256-bit switch arrays and two 512-bit plasma-coupled device (PCD) shift registers characterized by zigzag arrangement of conductance transistors has been developed. As compared with a conventional PCD image sensor which needs four-phase or six-phase shift pulses to drive the PCD shift registers, the newly developed sensor requires only two-phase shift pulses and greatly simplifies an external driving circuit. In addition, it can be fabricated by using only four photomasks, providing good cost performance.