Patent ID: 8600245

Claim:
An image forming apparatus that transfers an image formed on a photosensitive element onto a recording medium, the image forming apparatus comprising: a patch-image generating unit configured to generate a patch image for measuring a color reproduction characteristic and correcting color, the patch image includes mixed-color patch sets each including a plurality of patches each formed by overlaying a plurality of color materials, patches having the same color and the same tone value included in the mixed-color patch sets are arranged away from each other in a circumferential direction of the photosensitive element, and a distance between same tone patches, which are two patches having the same color and the same tone value, included in the mixed-color patch sets is close to (N+½) times the length of a period of uneven density which periodically occurs in the circumferential direction of the photosensitive element (N is an integer equal to or greater than 0); and an image forming unit configured to form the generated patch image on the recording medium, wherein the patch image includes single-color patch sets each including a plurality of patches each formed of a single color material, and the single-color patch sets are arranged between the mixed-color patch sets.