Patent ID: 8902480

Claim:
An image forming apparatus provided with an automatic document feeder for conveying a document subject to the reading position on a document glass, comprising: an image sensor configured to extend in a horizontal scanning direction; a carriage configured to move in a vertical scanning direction orthogonal to the horizontal scanning direction to change a reading position of a document; a guide section configured to have a guide surface for guiding the document to the document glass, and a white part extending in the horizontal scanning direction, a first colorizing part having a color lower in brightness than the white part and extending in the horizontal scanning direction and a second colorizing part having a color lower in brightness than the first colorizing part and extending in the horizontal scanning direction which are formed on the guide surface in line in the vertical scanning direction; and a reading control section configured to move the carriage to align the reading position in the vertical scanning direction with one of the white part, the first colorizing part and the second colorizing part and execute a reading processing.