| 摘要 |
PROBLEM TO BE SOLVED: To reduce manufacturing cost without increasing the size of an image forming apparatus when both a travelling speed detection mechanism for an intermediate transfer belt and a movement mechanism for varying the position of the intermediate transfer belt according to a printing format are adopted for the image forming apparatus.SOLUTION: An image forming apparatus 1 includes: an intermediate transfer belt 125; a plurality of developing units 128 and a primary transfer roller 126; a movement mechanism 52 for moving the intermediate transfer belt 125; a rotary encoder 60 for detecting the travelling speed of the intermediate transfer belt 125; and an actuator 70 for varying the posture according to an action of the moving mechanism 52. The actuator 70 does not interfere between a light emission unit 6021 and a light reception unit of the rotary encoder 60 when the intermediate transfer belt 125 is in the positions of monochrome printing or color printing and interferes between the light emission unit 6021 and the light reception unit when the intermediate transfer belt 125 is moving from the monochrome printing to the color printing. |
