Patent ID: 8571451

Claim:
An image forming apparatus calculating an amount of deviation of an image forming position from a reference, the amount of deviation being caused by thermal effect in the apparatus, the image forming apparatus comprising: an estimating unit for estimating the amount of deviation with time; a mark forming unit for forming a color deviation detection mark; a detecting unit for detecting reflected light upon irradiation of the formed color deviation detection mark with light; a control unit for causing the mark forming unit to form the color deviation detection mark and causing the detecting unit to perform detection at a timing when the amount of deviation estimated by the estimating unit is estimated to reach a threshold value; and a setting unit for setting the estimating unit so that an amount of deviation that is estimated becomes close to the amount of deviation that actually occurs based on the amount of deviation detected at the timing and the amount of deviation estimated by the estimating unit, wherein the control unit causes the mark forming unit to form the color deviation detection mark and causes the detecting unit to perform the detection at another timing different from the timing when the amount of deviation reaches the threshold value again after the setting by the setting unit is performed.