Patent ID: 8045225

Claim:
An image forming apparatus comprising: a data recording unit configured to store an amount of misregistration of a scanning line with respect to an ideal scanning line when a plurality of laser beams is scanned in a main scanning direction; a calculation unit configured to calculate a shape of the scanning line when the plurality of laser beams is scanned in the main scanning direction based on the amount of misregistration stored in the data recording unit, and to determine a scanning line curvature cancellation curve which cancels misregistration of the calculated shape of the scanning line; and an image forming unit configured to form an image that reflects the scanning line curvature cancellation curve by shifting image data which is read out from a memory unit in a sub scanning direction according to the scanning line curvature cancellation curve determined by the calculation unit, wherein the image forming unit corrects the amount of misregistration which is smaller than a main scanning line interval by adjusting a transfer point at which the image data is shifted in the sub scanning direction, the transfer point is a position at which the scanning line curvature cancellation curve is divided for each main scanning line interval at a reference position which is an ideal scanning position, and wherein the image forming unit sets the reference position at a position that cancels the amount of misregistration smaller than the main scanning line interval if the amount of misregistration includes an amount of misregistration smaller than the main scanning line interval, and does not change the reference position if the amount of misregistration does not include an amount of misregistration smaller than the main scanning line interval.