Patent ID: 7471426

Claim:
An image reading apparatus which reads images on the reading face of a document in color or in monochrome, the image reading apparatus comprising: a line sensor which includes a plurality of color line sensors for reading a color image and a monochromatic line sensor for reading a monochromatic image different from each of the color line sensors; a scanning section on which an optical system for directing light from the reading face of the document to the line sensor is provided; a driving mechanism which moves the scanning section in a feed direction with respect to the reading face of the document; a reference plate which is provided in front of the leading edge of the reading face of the document in the feed direction in which the scanning section is moved by the driving mechanism; a color reference reading section which, when the reading face of the document is read in color, starts to read the reference plate with the color line sensor at the time when scanning positions of some of the plurality of color line sensors reach a predetermined reading start position for the reference plate; a monochromatic reference reading section which, when the reading face of the document is read in monochrome, starts to read the reference plate with the monochromatic line sensor at the time a scanning position of the monochromatic line sensor reaches a scanning start position for the reference plate set in a range from the predetermined reading start position for the reference plate to a scanning position at which each of the color line sensors starts reading the reference plate by the color reference reading section; and a correcting section which corrects the image of the document read by each of the color line sensors, in accordance with data obtained by reading the reference plate by the color reference reading section, and corrects the image of the document read by the monochromatic line sensor in accordance with data read by the monochromatic reference reading section.