| 摘要 |
In an electrophotographic device of the type including a belt-type charge retentive member, driven along an endless path through a series of image processing stations by a frictionally engaging driving member, including a blade cleaning station for removing residual toner and debris from the member after transfer of a toner image to a final substrate and an arrangement for controlling the driving member to selectively drive the charge retentive member in either direction along the endless path, so that the member may be occasionally back tracked to clear debris accumulating at the blade cleaner, the back tracking movement is controlled by provision of at least first and second sensor detectable indicia on the charge retentive member, spaced therealong at an interval equivalent to the desired back tracking distance. A sensor suitable for detecting the detectable indicia on the charge retentive member is provided, to produce and direct detection signals to a machine controller controlling the back tracking operation of the device in accordance with detection of the indicia. Alternatively, successive detections of the same indicia during normal operation may be used as a measurement of average belt velocity. |
