| 摘要 |
<P>PROBLEM TO BE SOLVED: To maintain the state that a position detecting sensor can be operated always normally and to prevent biasing of an endless belt by cleaning the position detecting sensor using the light to detect the position of a member, i.e. the endless belt having no cut lines, in a short period of time. <P>SOLUTION: The belt drive unit is provided with the endless belt, at least two or more rollers for supporting the endless belt, the non-contact position detecting sensor for detecting the position at the end of the endless belt and a function to correct the movement of the endless belt in the axial direction of the rollers in accordance with the result of the detection by the position detecting sensor. The position detecting sensor is made rotatable within the plane of the endless belt and the belt drive unit is provided with a cleaning means for the position detecting sensor within the rotation route thereof. <P>COPYRIGHT: (C)2004,JPO |
