| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming device capable of keeping a developing gap at high accuracy for a long period by reducing the number of times of the pressure switching operation of developing units. SOLUTION: In the image forming device which is capable of selecting plural image forming modes (positive and negative modes), provided with a photoreceptor (image carrier) 1 carrying a toner image and positive and negative developing units 5 and 6 and presses the corresponding developing unit 5 (6) against the photoreceptor 1 and separates the other developing unit 6 (5) from the photoreceptor 1, in each image forming mode, the pressed states of the developing units 5 and 6 contributed to the formation of an image are kept after an image forming operation is completed as well and when the image forming mode is changed, the pressed states of the developing units 5 and 6 are switched, the developing unit 6 (5) corresponding to the changed image forming mode is pressed against the photoreceptor 1 and the other developing unit 5 (6) is separated from the photoreceptor 1. Thus, only when the image forming mode is changed, the developing units 5 and 6 are switched so that the number of the pressure switching operation times of the developing units 5 and 6 is reduced. |
