Adf Registration - Lexmark CX725 Service Manual

ADF registration

After passing through the pick assembly, the document actuates the sensor (pick). Actuating the sensor
determines that this side is the first side of the document to be scanned for a two-sided scan job. The sensor
(pick) triggers a count to track the position of the document between the sensor (pick) and the paper feed 1
roller. The count is generated by the encoder on the transport motor.
Note: Multiple feeds are often due to a worn restraint roller. Replace the restraint roller (separator roller CRU)
if necessary.
After the sensor (pick) is triggered, the scan document is moved to the paper feed 1 roller. The roller at this point
is not moving, held in place by a clutch. When the document reaches the roller, the roller does skew correction
on the document. The clutch releases the roller when the counter, triggered by the sensor (pick), reaches a
predetermined count. The roller then rotates and moves the document along the paper path.
The scan document passes through the paper feed 1 roller and actuates the sensor (trail). The sensor detects
the trailing edge of the document as it passes by. This enables the ADF to stop the roller and initiate the next
document to be picked and undergo skew correction. In addition, when the leading edge of the document
actuates the sensor, a count is initiated to track the position of the document from the sensor (trail) to the sensor
(1st scan). If the sensor (1st scan) is not reached at a predetermined interval, then a paper jam error is triggered.
Note: 283.xx paper jam errors are traceable to the sensor (trail). Check the actuator for paper or other debris.
Make sure that the sensor actuator moves properly.
1
2
3
4
1 Paper feed 1 roller
2 Sensor (trail)
3 Sensor (pick)
4 Paper feed 2 roller
Appendix C: Theory of operation
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