Time delay and integration imagers and their applications to image acquisition cameras

A family of experimental time-delay and integration (TDI) charge-coupled imaging devices has been designed and built using a minimally-modified logic/memory NMOS process. These imagers yield more favorable tradeoffs between image quality, speed, and illumination than conventional linear imagers and are suitable for high-speed scanning of color or monochrome documents at low illumination power. The design and construction of a prototype scanning camera using the 3072 × 32 TDI devices is also described. Intended for publishing applications, the camera is capable of capturing both monochrome and color images. At half-page document size, the scanning resolution is 300 pixels/in. Special color filters are used to produce colorimetric outputs. Both reflective and transmittive illumination are provided to scan both prints and transparencies of various sizes.