Patent ID: 7561840

Claim:
A transfer endless belt device applied to an image forming apparatus, comprising: an endless belt for forming a loop-shaped moving path, stretched out between a driving roller and a driven roller which are affixed to positions inside the apparatus; a plurality of image bearing members provided in a row within a prescribed range along a moving direction of the endless belt; a plurality of image transferring members disposed within the moving path, and respectively opposed to the image bearing members across the endless belt; an image transferring member supporting mechanism for approximating and separating the image transferring members to and from the image bearing members; and a belt supporting mechanism for contacting and separating the endless belt to and from the image bearing members in accompaniment of an operation of the image transferring member supporting mechanism, wherein the image transferring member supporting mechanism and the belt supporting mechanism are disposed within the moving path, and the belt supporting mechanism is rotatably supported and includes a first eccentric cam whose circumferential surface abuts an inner circumferential surface of the endless belt.