| 摘要 |
PROBLEM TO BE SOLVED: To enable density correction with a simpler configuration compared to the case of disposing individual sensors on an intermediate transfer belt and on a photoreceptor drum, and detecting density unevenness respectively on the intermediate transfer belt and photoreceptor drum, thereby correcting density.SOLUTION: An image forming apparatus performs: obtaining intermediate transfer belt density information that is produced by correlating intermediate transfer belt density on one complete circumference of an intermediate transfer belt 26, the density detected by a density sensor 44, with positions on the intermediate transfer belt 26 along its circumferential direction; obtaining patch image density information that is produced by correlating patch image density of a density patch image formed throughout one circumference of the intermediate transfer belt 26, the density detected by the density sensor 44, with positions on the intermediate transfer belt 26 along its circumferential direction and positions on a photoreceptor drum 30 along its circumferential direction; calculating a drum-unevenness characteristic value for the photoreceptor drum 30 in its circumferential direction for each position on the photoreceptor drum along its circumferential direction on the basis of the aforementioned two pieces of density information; and correcting drum-unevenness of the photoreceptor drum 30 in its circumferential direction on the basis of the drum-unevenness characteristic value. |
