| 摘要 |
<p>PROBLEM TO BE SOLVED: To suppress rubbing between a color photoreceptor drum and an intermediate transfer belt in such a configuration that rotation of the intermediate transfer belt and driving of a contact/separation mechanism that varies a positional relationship between the photoreceptor drum and the intermediate transfer belt are carried out by a common first motor.SOLUTION: A contact/separation mechanism switches conditions of a positional relationship between the photoreceptor drum and the intermediate transfer belt in an order of wholly separated positions, partially contact positions, and wholly contact positions. A monochromatic mode is executed after the relationship is transferred from the wholly separated positions to the partially contact positions. Upon ending the monochromatic mode, the relationship is transferred from the partially contact positions to the wholly separated positions by way of the wholly contact positions where the whole photoreceptor drums are in contact with the intermediate transfer belt. During the process, a color photoreceptor drum not used in the monochromatic mode is driven to rotate. Thereby, the color photoreceptor drum can be prevented from rubbing on the intermediate transfer belt while the drum is subjected to the conditions of the wholly contact positions.</p> |
