Duplex Document - Lexmark X850e Service Manual

1st document

Duplex document

The ADF scans the image on Side 1 (side facing up when set on the tray), inverts the document sheet, scans
the image on Side 2 (side facing down when set on the tray), and then ejects the document sheet while inverting
it.
Therefore, the duplex document sheet is ejected with Side 2 up as with the simplex document sheet.
For two simplex documents, feed is performed in the following sequence.
1.
The first document sheet (Side 1) is fed to the ADF transport roll assembly. (see Pre-feed)
2.
The document sheet (Side 1) is fed to the ADF registration roll assembly and then fed to the scan feed
reference position. (see Pre-registration)
3.
The document sheet (Side 1) is fed at the feed speed corresponding to the selected magnification, and the
image is scanned with the exposure lamp at the scan position. (see Scan control)
4.
As the image is scanned, the document (Side 1) is fed by the ADF feed-out roll assembly and ADF exit roll
assembly that are driven by the ADF registration motor rotating in the reverse direction (CCW direction).
When the trail edge of the document has passed through the sensor (inverter), the ADF registration motor
changes its rotational direction to the normal direction (CW direction) to drive the ADF exit roll assembly in
the opposite direction. Thus, the document sheet is inverted and fed to the ADF transport roll assembly
again.
5.
When the sensor (ADF pre-registration) detects the lead edge of the document sheet (Side 2), the inverter
solenoid assembly is turned on to release the nipped ADF exit roll assembly and exit pinch roll. If these
rolls are not released, the lead edge of the document sheet (Side 2) reaches the ADF exit roll assembly
before the trail edge of the document sheet (Side 2) leaves the ADF exit roll assembly when the document
sheet (Side 2) is long in the slow scanning direction.
6.
The document sheet (Side 2) is fed to the ADF registration roll assembly and then fed to the scan feed
reference position. (see Pre-registration)
7.
The document sheet (Side 2) is fed at the feed speed corresponding to the selected magnification, and the
image on it is scanned with the exposure lamp at the scan position. (see Scan control)
8.
When the trail edge of the document sheet (Side 2) passes through the sensor (ADF pre-registration), the
inverter solenoid assembly is turned off to nip the ADF exit roll assembly and exit pinch roll.
9.
As the image is scanned, the document sheet (Side 2) is fed by the ADF feed-out roll assembly and ADF
exit roll assembly that are driven by the ADF registration motor turning in the reverse direction (CCW
direction). When the trail edge of the document sheet (Side 2) has passed through the sensor (inverter),
the ADF registration motor changes its rotational direction to the normal direction (CW direction) to drive
the ADF exit roll assembly in the opposite direction. Thus, the document sheet (Side 2) is inverted and fed
toward the ADF transport roll assembly again.
10.
At the same time, the ADF feed motor assembly rotates in the normal direction (CW direction) to drive the
ADF transport roll assembly, thus feeding the document sheet (Side 1) toward the exit.
Sensor (ADF pre-registration)
2nd documant
General information
7500-XXX
1-39