Patent ID: 8036551

Claim:
An image forming apparatus comprising: an image forming section that forms an image on an object; a controlling section that controls the image forming section to form a calibration pattern on the object, the calibration pattern including a plurality of marks in a first group and a plurality of marks in a second group, the plurality of marks in each of the first group and the second group being arranged in a first direction over a predetermined range, the plurality of marks in each of the first group and the second group including first marks and second marks, the first marks being parallel to a second direction to the first direction and the second marks being non-parallel to the second direction, a position of the first marks in the first group corresponding to a position of the second mark in the second group in the second direction in at least part of the predetermined range, a position of the first marks in the second group corresponding to a position of the second marks in the first group in the second direction in at least part of the predetermined range; a detecting section that detects the first mark and the second mark formed on the object; and a correcting section that corrects, based on the detected first mark, a deviation in the first direction of an image forming position at which the image forming section forms an image, and corrects, based on the detected second mark, a deviation in the second direction of the image forming position.