Patent ID: 8886066

Claim:
An image forming apparatus comprising an image forming unit that includes a plurality of image bearing members and a plurality of transfer members, which form nip parts with the plurality of the image bearing members through an intermediate transfer member onto which a toner image developed on each of the plurality of image bearing members is transferred or through a transfer material bearing member bearing a transfer material onto which the toner image developed on each of the plurality of image bearing members is directly transferred, the image forming apparatus comprising: a pattern forming unit that controls the image forming unit to form a position deviation detection pattern on the intermediate transfer member or the transfer material bearing member, the position deviation detection pattern including a first mark and a second mark, wherein when the first mark is formed, toners have entered into two or more nip parts among the nip parts, and when the second mark is formed, toners have entered into nip parts numbering less than the number of the two or more nip parts into which toners have entered when the first mark is formed; a detection unit which detects positions of the first mark and the second mark which are included in the position deviation detection pattern; a memory that stores history data of use of the intermediate transfer member or the transfer material bearing member; and a correction unit which corrects a relative velocity between the image bearing members and the intermediate transfer member or the transfer material bearing member, based on the positions of the first mark and the second mark which are detected by the detection unit and the history of use of the intermediate transfer member or the transfer material bearing member stored in the memory.