Patent ID: 7277667
Filing Date: 2007-10-02
Classification: G03G

Abstract:
1. An endless belt device comprising: an endless belt; a plurality of rotary members rotatably supporting the endless belt, one of the plurality of rotary members including a marker formed on a part of a circumferential surface of a rotation axis thereof; a reflection-type sensor arranged to oppose the circumferential surface of the rotation axis of the one of the plurality of rotary members to detect the marker formed on the circumferential surface by detecting reflected light from the marker; a sensor holder completely surrounding the rotation axis of the one of the plurality of rotary members and supporting the reflection-type sensor, the sensor holder including a bearing part accommodating the rotation axis of the one of the plurality of rotary members; and a frame supporting the plurality of rotary members and the sensor holder, to position the bearing part of the sensor holder to accommodate the rotation axis of the one of the plurality of rotary members, wherein a rotation speed of the endless belt is detected by detecting the marker on the circumferential surface of the rotation axis of the one of the plurality of rotary members by the reflection-type sensor.