Image forming apparatus, and color shift correction method

PROBLEM TO BE SOLVED: To easily and inexpensively perform accurate color deviation correction in a short time without being affected by scratch or foreign matter on an image carrier or irregularities of the surface thereof. SOLUTION: The pattern for color deviation correction includes color patterns of the same color, which are formed on the downstream side and upstream side in a carrying direction of an intermediate transfer belt with a certain given space, wherein each of the color patterns is composed of a reference color and a plurality of non-reference colors, and each color pattern is disposed adjacently along the carrying direction of the intermediate transfer belt. A spacing position constituted by each color pattern is detected to calculate a color deviation amount, and a color deviation correction amount is calculated from the color deviation amount to perform color deviation correction. COPYRIGHT: (C)2011,JPO&INPIT