Epson GT-1200, Service Manual

Page: 91 / 157

ADF Operating Principles
Rev. A
2-6
REVERSE FEEDING
In the reverse feeding mode, document is fed in the following order:
The document is fed.
®
The document is reversed.
®
Image is scanned
®
The document is reversed again
. ®
Image on the reversed side is scanned.
Setting a document
1.
Document is set in the paper feeding tray.
Pre-feeding
"Pre-feeding" consists of operations which pick up the document from the
paper feed tray and transport it to the scanning position according to the
reverse feed command sent from the scanner.
2. Step 2) After the wait shutter solenoid turns on, the document is
picked up and transported from the paper feed tray by the forward
rotation of the paper feed motor. The motor then stops rotating when
the registration sensor comes on. This sequence, from picking up the
document to the registration sensor's coming on, is called registration
operation. The transportation motor and the paper eject/reverse
motor also rotate forward to perform dummy ejection to prevent a
remaining document from jamming when the ADF is feeding another
document. This is performed for every feeding motion no matter a
document is remaining in the ADF or not.
3. After the registration operation is carried out, the paper feed motor
starts rotating forward to transport the document. The document is
transported to the position where the timing sensor comes on, which
means the end of the pre-feeding operation. Ongoing dummy ejection
carries on.
4. The transportation motor and paper feed motor rotate forward and
backward, respectively, to transport the document onto the platen
glass. The paper feed motor stops rotating when the registration
sensor goes off. The flapper solenoid comes on to switch the paper
path to the paper eject/reverse mechanism side.
Figure 2-19. Setting a Document (Step 1)
Figure 2-20. Pre-feeding (Step 2)
Figure 2-21. Pre-feeding (Step 3)
Figure 2-22. Reverse Feeding (Step 4)