| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus that aligns an electrostatic image scale 51M of a photoconductor drum 1M to an electrostatic image scale 53 of an intermediate transfer belt 9 without causing a fluctuation in speed of the photoconductor drum 1M, so as to avoid the occurrence of a reduction in image quality and vibration of the image forming apparatus.SOLUTION: During image formation, a drive control unit 22M controls the rotation speed in every moment of a photoconductor drum 1M to position an electrostatic image scale 51M to an electrostatic image scale 53 that passes through a transfer position TM in real time. Before the start of the image formation, the drive control unit 22M adjusts formation time of the electrostatic image scale 51M by an exposure device 3M by an amount of phase shift between a pulse signal output from a position detection unit 21M after detection of the electrostatic image scale 53 and a pulse signal output from a rotation angle detection unit 52M, while maintaining the phase shift constant. With this configuration, an electrostatic image scale 51Y is formed at a position on the photoconductor drum 1M positioned with the electrostatic image scale 53, and thereby eliminating the need of a large amount of control to offset large phase shift. |
