Control; Document Size Detection At Scanner Unit Assembly - Lexmark X850e Service Manual

7500-XXX

Control

Document size detection at scanner unit assembly

The width (fast-scan-directional size) of the document sheet on the Platen Grass is detected with the CCD
image sensor, and the length (slow-scanning-directional size) is detected with the sensor (platen length APS 1)
and the sensor (platen length APS 2).
Document size detection timing
The size of the document sheet on the platen glass is detected at the following timings:
•
When the Platen Cover (ADF) is closed
•
When the START button is pressed with the Platen Cover (ADF) open
Identification of standard document sizes
The width of the document sheet is detected in millimeters with the CCD image sensor to determine the size in
the fast scanning direction. With respect to a pair of documents whose sizes in the fast scanning direction are
the same, the document size is determined by detecting paper presence/absence at the positions of sensor
(platen length APS 1) and sensor (platen length APS 2) (e.g., A4LEF vs. A3SEF; 8.5x11SEF vs. 8.5x13SEF).
The standard document sizes to be identified by the same given detection information are defined on an
area-by-area basis. Each area is to be set in the system data.
The figure below shows the positional relationships among the scan position of the CCD image sensor and the
positions of sensor (platen length APS 1) and the sensor (platen length APS 2).
CCD scan position
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MFP Service Manual
Sensor (platen
length APS 1)
Sensor (platen
length APS 2)