SIGNAL PROCESSING INTEGRATED CIRCUIT, IMAGE READING DEVICE, AND IMAGE FORMING APPARATUS

摘要

A signal processing IC that receives analog signals each corresponding to one of three colors from a color linear image sensor includes two systems of input-signal processing for each color each including at least a sample-and-hold circuit, a multiplexer circuit, a variable gain amplifier, and an A/D converter circuit. The sample-and-hold circuit samples and holds an analog signal. The multiplexer circuit multiplexes analog signals of the two systems subjected to sampling and holding into a signal of one system. The variable gain amplifier amplifies the signal output from the multiplexer circuit. The A/D converter circuit converts the amplified signal to digital data.