Patent ID: 8417140

Claim:
An image forming apparatus comprising: a plurality of toner-image forming units that form electrostatic latent images on image carriers by performing exposure in accordance with image data which is supplied, and that form toner images by developing the electrostatic latent images; an intermediate transfer body onto which the toner images formed by the plurality of toner-image forming units are transferred; a controller that performs control of causing at least one of the plurality of toner-image forming units to be used to form the toner images and the intermediate transfer body to contact each other, and control of separating the plurality of toner-image forming units except the at least one of the plurality of toner-image forming units and the intermediate transfer body from each other; a detector that detects a test pattern formed by the plurality of toner-image forming units; an instruction acceptance unit that accepts an instruction for performing a detection process with the detector; and a memory that stores a first forming mode, which is used to form an image, among a plurality of forming modes indicating combinations of toner-image forming units to be used to form the toner images among the plurality of toner-image forming units, and that stores a second forming mode, which is used to form the test pattern, among the plurality of forming modes, wherein, when the instruction acceptance unit accepts the instruction, the test pattern is formed using at least one of the plurality of toner-image forming units corresponding to the second forming mode stored in the memory, and is detected by the detector.