Patent ID: 8109602

Claim:
An image forming apparatus comprising: a recording head having aligned in a secondary scanning direction a plurality of dot forming sections each of which is a component for forming a dot on a recording medium; a primary scanning portion for moving the recording head relative to the recording medium in a primary scanning direction intersecting the secondary scanning direction; and a secondary scanning portion for moving the recording head relative to the recording medium in the secondary scanning direction, wherein the recording head is moved relative to the recording medium by means of the primary scanning portion and the secondary scanning portion so as to form, on the recording medium, a subject image which is a predetermined image; a first instruction portion for instructing the recording head, the primary scanning portion, and the secondary scanning portion to form the subject image of a first resolution which is previously set; a second instruction portion for instructing the recording head, the primary scanning portion, and the secondary scanning portion to form, in an area other than an area in which the subject image on the recording medium is formed, a test pattern of a second resolution which is previously set and is different from the first resolution; a first pattern storage portion for previously storing therein first pattern information representing image information of the second resolution corresponding to the test pattern of the second resolution; and a pattern generation portion for reading the first pattern information from the first pattern storage portion and generating, based on the first pattern information read, second pattern information representing image information of the first resolution corresponding to the test pattern of the second resolution, wherein the second instruction portion operates so as to form the test pattern of the second resolution based on the second pattern information generated by the pattern generation portion.