Adf Paper Path Sensors - Lexmark XM3250 Service Manual

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After the sensor (ADF paper present) detects paper in the ADF tray, the pick roller drops and advances the
paper into the ADF.
The paper passes through the feed roller and separator roller. The separator roller minimizes the possibility of
feeding multiple sheets.
The paper then actuates the sensors (pick and deskew). The sensor (pick) detects the leading edge of the paper
and adjusts the pick/feed timings while the sensor (deskew) detects the paper for any skew. The deskew roller
slows down the paper to perform the skew correction.
Note: The motor (pick) runs the pick and feed rollers.
For duplex scan jobs, the paper actuates the sensor (ADF 1st scan) and proceeds to the 1st scan area. Failure
to actuate the sensor results to a paper jam error. The back side of the document is scanned.
The transport rollers continue to advance the paper until it actuates the sensor (ADF 2nd scan) and reaches
the 2nd scan area. For simplex or duplex scan jobs, the front side of the document is scanned on the 2nd scan
area.
The exit roller picks and drops the paper into the ADF bin. The motor (transport) runs the transport, deskew,
and exit rollers.

ADF paper path sensors

Theory of operation
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