Belt unit, transfer belt unit, and image forming apparatus

摘要

A belt unit includes a belt, a contact member, a movable member, an eccentric cam, a contact-separation mechanism, and a braking unit. The contact member is configured to come into contact with the belt. The contact-separation mechanism allows the movable member to move according to the rotation of the eccentric cam to control contact and separation between the contact member and the belt. The braking unit controls the rotation of the eccentric cam by a predetermined angle.