| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device and an image forming device capable of preventing an abnormal image from being caused by the history of the contact of a photoreceptor with a developing roller and coping with color image formation. SOLUTION: The position of the developing roller (303) with respect to the developing device (3) or a supply roller (304) is made movable, and the roller (303) is retreated from the photoreceptor (1) at image non-forming time. After finishing image forming operation, bias for generating electric field to move toner from the roller (303) to the roller (304) is applied to the rollers (303) and (304), and the toner on the roller (303) is recovered to the roller (304). Furthermore, the dark potential VD of the photoreceptor (1), potential after exposure VL and developing bias voltage VB are set to satisfy 0<|VD|-|VB|<|VD-VL|<400 V. |
