Belt unit and image forming apparatus

摘要

A belt unit is provided with an endless belt, a driving roller, and a pair of guide ribs. The driving roller is disposed on an inner peripheral surface side of the endless belt and drives the endless belt. The pair of guide ribs is placed on each opposite widthwise end of the inner peripheral surface of the endless belt and contacts both end faces of the driving roller, thus preventing meandering of the endless belt. Additionally, the driving roller is equipped with a low friction region at both opposite lengthwise ends in a predetermined width and the low friction region is configured to have a friction coefficient that is lower than a friction coefficient of a region adjacent to the low friction region.

主权项

1. A belt unit comprising:
an endless belt; a driving roller that is disposed on an inner peripheral surface side of the endless belt and drives the endless belt; a pair of guide ribs that is placed on each opposite widthwise end of the inner peripheral surface of the endless belt and contact both end faces of the driving roller, thus preventing meandering of the endless belt; and elastic rubber that is wound around at least the both opposite lengthwise ends of the outer peripheral surface of the driving roller, wherein:
the elastic rubber has a first region at sides of both end faces of the driving roller and a second region adjacent to the first region;the first region is mirror finished; andthe second region has a friction coefficient that is higher than a friction coefficient of the first region.