Patent ID: 9201351
Filing Date: 2015-12-01
Classification: G03G

Abstract:
1. An image forming apparatus, comprising: a first image bearing member to be rotationally driven; a second image bearing member to be rotationally driven; a first toner image forming portion configured to form a toner image on the first image bearing member; a second toner image forming portion configured to form a toner image on the second image bearing member; an intermediate transfer member arranged so as to be brought into contact with and separated from the first image bearing member and the second image bearing member, the intermediate transfer member being configured so that the toner image formed on the first image bearing member and the toner image formed on the second image bearing member are transferred onto the intermediate transfer member; a contact-separation mechanism configured to be driven so that the first image bearing member and the second image bearing member are brought into contact with and separated from the intermediate transfer member, the contact-separation mechanism being configured to be driven to move to a fully separated position in which the first image bearing member and the second image bearing member are separated from the intermediate transfer member, a partly contacted position in which the first image bearing member is separated from the intermediate transfer member and the second image bearing member is in contact with the intermediate transfer member, and a fully contacted position in which the first image bearing member and the second image bearing member are in contact with the intermediate transfer member in order as listed a common drive source configured to drive the intermediate transfer member and the contact-separation mechanism separately; a connection-disconnection device configured to connect and disconnect a drive transmission from the common drive source to the contact-separation mechanism; and a control portion configured to control a position of the contact-separation mechanism, wherein the control portion locates the contact-separation mechanism in the fully contacted position when a first mode for forming the toner image by both of the first image bearing member and the second image bearing member is performed, wherein the control portion stops drive to the first image bearing member and locates the contact-separation mechanism in the partly contacted position when a second mode for forming the toner image by only the second image bearing member is performed, and wherein the control portion rotationally drives the first image bearing member when the contact-separation mechanism is moved to the fully contacted position in association with a performance of the second mode.