Canon i-SENSYS MF4120, Service Manual

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Chapter 4
4-1
4.1 Basic Operation
4.1.1 Basic Operation
0014-7869
i-SENSYS MF4150 / i-SENSYS MF4140 / i-SENSYS MF4120 /
The Auto Document Feeder (ADF) mounted onto this host machine is dedicated to stream-reading.
1 motor (DF motor: M3) is engaged in pickup/feeding/delivery.
At the start of copy/fax/scan, the DF motor (M3) is driven by the drive command from the SCNT to pickup/feed the originals set face up on the original tray one
by one in order from the top. The original is scanned by the contact sensor when moving through the copyboard glass, and then delivered face down to the original
delivery assembly.
F-4-1
Within the ADF pickup assembly is the stop [1] for the purpose of preventing the push-in of original, which descends/ascends in conjunction with the gear [2] on
the end of the pickup roller shaft.
F-4-2
- When the originals are moving through the machine
By the CW drive of the DF motor (M3), which is transmitted to the pickup roller via the gear/spring clutch and results in positive rotation of the pickup roller,
original pickup is performed. At this point, the gear on the pickup roller shaft rotates positively as well, ascending the stop. When the originals are moving
through the equipment, the stop is kept ascended.
- At detection of original being set and after delivery of the last sheet of the original
The gear on the pickup roller shaft rotates negatively by the CCW drive of the DF motor (M3), descending the stop. At the CCW drive, the drive is not transmitted
to the pickup roller via the spring clutch, leaving the pickup roller stopped.
SCNT
J711
1
2
3
4
A0
A0*
B0
B0*
M3
M3
[1]
[2]
( )
( )