US Patent 7317562 Image reading apparatus with plural sensor IC chips

An image reading apparatus includes a plurality of sensor IC chips aligned in a row. Each of the sensor IC chips incorporates a plurality of light receiving elements. The plurality of light receiving elements successively output image signals as serial analog signals corresponding to received amount of light upon receiving light from an object to be read. The number of the sensor IC chips is an integer multiple of three. The sensor IC chips are divided into blocks. The number of the blocks is an integer multiple of three. The image signals are outputted on a block-by-block basis.