Image forming apparatus, program and positional error correction method

摘要

An image forming apparatus includes an electrophotographic process part for image formation provided for an image carrying medium for each color; a non-end moving part moving images transferred thereto from the respective image carrying media for the respective colors; and an image detecting part detecting an image formed on the non-end moving part. The respective electrophotographic process parts are disposed in sequence along the non-end moving part, and form positional error detection marks on the non-end moving part; the image detecting part detects the thus-formed positional error detection marks; and positional error correction is performed based on a result of detection thus performed by the image detecting part. The apparatus comprises a control part having at least two modes in the positional error correction; and the control part performs control such that one of the at least two modes is selected according to a positional error amount detected by the image detecting part.