Canon imageRUNNER ADVANCE 4551i Service Manual page 82

■ Document Pickup/Feed
● Basic Operation
After pressing the start key with a document placed on the Document supply tray, a document is picked up in the following
procedure.
Pickup operation
The Pickup motor (M1) drives to lower the Pickup roller assembly through the Pickup clutch (CL1) and then the Pickup roller
rotates to feed a document.
The stopper rises in conjunction with the Pickup roller assembly. The Separation roller is used to improve the separation
performance while feeding a document.
Formation of loop
During Pickup Operation, the Lower registration roller is stopped rotating while moving a document against the Upper/Lower
registration rollers and then form a loop. Thus it prevents a document from skewing.
Start of reading of reverse
side of second document sheet
End of reading of reverse
side of second document sheet
Stop after feeding the second
document sheet to reversal position
M1
Pickup roller
CL1
Document
Stopper
Removal of idle registration
loop at the second document sheet/
Re-pickup/Release of
the Lower delivery reversal roller
Delivery of second document sheet/
Pressurization at
the Lower delivery reversal roller
Completion of delivery of
second document sheet/end of job
M1
Pickup roller
CL1
Separation roller
69
2. Technology