| 摘要 |
PROBLEM TO BE SOLVED: To prevent degradation in image formation performance by changing the inertia moment of an image carrier, thereby reducing load on a driving device. SOLUTION: The fly wheel 20 provided on the image carrier has a movable member 24, a part of which is free to advance/retract toward/from a rotation center 21, and the movable member 24 rotationally symmetrically meshes with a pinion gear 25 by means of a rack 24a. Because the pinion gear 25 is rotated and driven by the driving means 26 independently of the fly wheel 20, the movable member 24 is caused to advance/retract toward/from the rotation center by the relative turn of the pinion gear 25 to the fly wheel 20, that is, a rotational-speed difference, and the inertia moment therefore changes. |
