Patent ID: 8045873

Claim:
An image forming apparatus for forming an image by superimposing a plurality of single-color images on a recording medium, the image forming apparatus comprising: an image carrier configured to carry an image; an image forming unit that is configured to form an image on the image carrier with predetermined density and transfers the image onto the recording medium, wherein the image forming unit forms a first pattern of black with a plurality-of density levels and a second pattern of a plurality of colors other than black with a plurality of density levels on the image carrier; a pattern detecting unit that detects the first pattern and the second pattern formed on the image carrier; a first adjusting unit that performs a first adjustment of adjusting density of black based on the first pattern detected by the pattern detecting unit when the image forming unit is to form an image that is to be transferred on the recording medium; a second adjusting unit that performs a second adjustment of adjusting density of colors other than black based on the second pattern detected by the pattern detecting unit when the image forming unit is to form an image that is to be transferred onto the recording medium; and a determining unit that determines whether to perform the first adjustment or to perform the second adjustment based on a type of the image to be formed on the recording medium, wherein the second pattern includes a plurality of patterns of respective colors other than black, and the image forming unit forms the patterns of the colors other than black on the image carrier in parallel to each other in a sub-scanning direction of the image carrier.