Patent ID: 9678459
Date: 2017-06-13
CPC Classifications: G03G

Claim:
1. An image forming apparatus comprising: an image carrier; a toner image forming unit configured to form a toner image on the image carrier; an endless transfer belt configured to convey a recording medium; a transfer roller forming a transfer portion configured to transfer the toner image on the image carrier onto the recording medium and to be urged toward the image carrier from an inner circumferential surface of the transfer belt across the transfer belt; a first stretch roller stretching the transfer belt, disposed at a position adjacent to and downstream of the transfer portion in a moving direction of the transfer belt, and including first tapered areas disposed on both end parts in a direction of an axis of rotation thereof where the diameter is smaller than a center part in the direction of the axis of rotation thereof such that the closer to both ends, the smaller the diameter becomes; a second stretch roller stretching the transfer belt, disposed at a position adjacent to and downstream of the first stretch roller in the moving direction of the transfer belt, and including second tapered areas disposed on both end parts in a direction of an axis of rotation thereof where the diameter is larger than a center part in the direction of the axis of rotation thereof such that the closer to both ends, the larger the diameter becomes; and a driving roller configured to drive the transfer belt, disposed at a position which is adjacent to and downstream of the second stretch roller and which is upstream of the first stretch roller, with respect to the moving direction of the transfer belt.