Patent ID: 8086156
Filing Date: 2011-12-27
Classification: G03G

Abstract:
1. A belt device for use in an image forming apparatus, the belt device comprising: an endless belt that is suspended in a tensioned manner by a plurality of rollers including a drive roller; a drive motor that drives the drive roller so as to move the belt in a predetermined direction of travel; a first detecting unit that detects an amount of displacement of the belt between a first set of the rollers in a widthwise direction of the belt; a second detecting unit which detects a displacement of the belt in the widthwise direction between a second set of the rollers which is different from the first set of the rollers and outputs a signal indicating to stop a movement of the belt, when the displacement of the belt in the widthwise direction is detected by the second detecting unit to be abnormal; a display which displays a message for a service call, when the second detecting unit detects the displacement of the belt in the widthwise direction is abnormal; and a correction unit that corrects displacement of the belt in the widthwise direction based on data from the first detecting unit without using data from the second detecting unit.