Canon LaserBase MF3220 Series, Service Manual

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Chapter 2
2-4
2.4 Pickup and Feed System
2.4.1 Overview/Configuration
2.4.1.1 Overview
0012-0892
F-2-4
T-2-4
Pickup and Feed Operation (from the cassette)
If the cassette paper sensor detects the presence of paper while the absence of paper is identified in the manual feed pickup assembly, the machine picks up paper
from the cassette.
When the main motor operates and the cassette pickup solenoid goes on, the cassette pickup roller makes a single rotation to pick up paper. The paper is then moved
from the transfer assembly to the fixing assembly by the feed roller; it is ultimately delivered outside the machine by the work of the delivery roller.
When the face-up cover is open, the paper is delivered face-up at the rear of the machine. If the face-up cover is closed, on the other hand, the paper is moved along
the feed guide of the cover, and is delivered face-down at the top of the machine by the work of the face-down delivery roller.
Pickup and Feed Operation (from the manual feed section)
When paper is inserted into the pickup assembly, the manual feed paper sensor detects the presence of paper, and the machine uses the feed roller to pick and hold
the leading edge of the paper. When printing starts, the machine turns on the manual feed pickup solenoid to stop the rotation of the feed roller so that the paper
will not move forward until the laser/scanner and the fixing unit become ready for operation. When the laser/scanner and the fixing unit become ready for operation,
the machine turns off the manual feed pickup solenoid to rotate the feed roller, thus moving the paper forward; the operation thereafter is identical to the operation
used for pickup from the cassette.
2.4.2 Other Control
2.4.2.1 Manual Pickup Control
0012-1874
Upon detection of manually inserted paper, the machine drives the main motor for the specified time to feed the paper to the position where it is to be fed between
the feed rollers. In addition, the machine turns on the feed roller (manual pickup) solenoid to stop rotating the feed rollers, thus preventing the manually inserted
paper from being fed askew. With the paper pressed against the feed rollers, the machine drives the main motor and turns off the solenoid to feed the paper between
the feed rollers.
2.4.2.2 Cassette Pickup Control
0012-1876
With the main motor running, the machine turns on the paper pickup solenoid at the specified timing to rotate the pickup rollers. If paper exists over the top sensor
at the start of timing retry, the machine stops cassette pickup control. If paper does not exist, the machine retries cassette pickup control.
[1] Cassette feed [12] Face-down delivery
[2] Cassette pickup roller [13] Main motor
[3] Separation pad [14] Cassette pickup solenoid
[4] Manual feed [15] Manual feed pickup solenoid
[5] Feed roller [16] Cassette paper sensor
[6] Transfer assembly (photosensitive drum, transfer
charging roller) [17] Manual feed paper sensor
[7] Fixing assembly (fixing film, fixing pressure roller) [18] Top sensor
[8] Delivery roller [19] Delivery sensor
[9] Face-up cover
[10] Face-up delivery
[11] Face-down delivery roller
[1] [13] [14] [16]
[7]
[8]
[9]
[10]
[11]
[19]
[12]
[2]
[3]
[5]
[15]
[4]
[17]
[18]
[6]