Image sensing module outputting color signals or monochrome signals depending on mode of operation

摘要

An image preprocessing apparatus, which processes image signals of an image of a scanned object, includes an image sensing module, a multiplexing unit and an analog signal processor. The image sensing module includes a number of monochrome image sensors, as well as a black-and-white (B/W) image sensor, outputting a number of monochrome analog image signals and a B/W analog image signal respectively. The multiplexing unit receives the B/W analog image signal and some of the monochrome analog image signals and then selects either the B/W analog image signal or these monochrome analog image signals as the output of the multiplexing unit. The analog signal processor receives the output of the multiplexing unit and the monochrome analog image signals that are not received by the multiplexing unit, and outputs a digital signal.