Canon imageRUNNER ADVANCE 4551i Service Manual page 84

■ Document Reversing
● Basic Operation
There are two types of document reversal operation: one that is performed from the top to the reverse side of the document and
the other that is performed from the reverse side to the top of the document.
Since the basic operation methods are identical, only the reversal operation performed from the reverse side to the top is discussed
below.
Top side pickup
The Read motor (M2) drives the Read roller 1 (upper) and the Platen roller to scan the surface of a document on stream reading.
After completion of scanning, Read motor (M2) drives the Read roller 2 (upper) and the Upper delivery reversal roller to feed a
document to the reverse point.
Read roller 1
(Upper)
Reversal/Feed 1
After the trailing edge of a fed document passes the Delivery reversal sensor (SR3), the Read motor (M2) stops.
Thus a document stops at the reverse point. The Read motor (M2) drives in reverse direction to feed a document to the Registration
roller and then it stops. After that, the Release solenoid (SL1) turns on to release the Lower delivery reversal roller.
Delivery reversal sensor(SR3)
Reversal/Feed 2
The Pickup motor (M1) drives the Lower registration roller through the Registration clutch (CL2) to feed a document to the Read
wait point.
Thus, the document is reversed. After a document is picked up again, turn OFF the Release solenoid (SL1) to pressurize at the
same time that reverse side reading is complete. After that, each operation is performed such as re-reverse, feeding and
delivering.
Pickup motor(M1)
Pickup clutch(CL1)
M2
Platen roller
M2
SL1
Stopper
Pickup roller
Feed roller
Separation roller
Upper delivery reversal roller
M2
Read roller 2(Upper)
M2
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2. Technology
Document
Stopper
SL1