Canon imageCLASS MF4100 Series, Service Manual

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Chapter 6
6-1
6.1 Overview/Configuration
6.1.1 Configuration
0014-5000
i-SENSYS MF4150 / i-SENSYS MF4140 / i-SENSYS MF4120 /
The image forming system is the core part of this machine, and is composed of the cartridge, the transfer charging roller, the fixing assembly, etc.
When receiving the print command from the SCNT board, the DCNT board activates the main motor to rotate the photosensitive drum, the developing cylinder,
the primary charging roller, the transfer charging roller and the pressure roller.
The surface of the photosensitive drum is evenly charged negative by the primary charging roller, and the laser beam converted with the video signal (VDO, /VDO)
is reflected to the surface of the photosensitive drum to form the latent image by the laser diode.
The latent image formed on the photosensitive drum is turned visible with the toner on the developing cylinder and is transferred on the paper by the transfer charg-
ing roller. The transferred toner turns into the permanent image on the paper when the heat and pressure are applied there at the fixing assembly. The cleaner blade
removes the residual toner on the surface of the photosensitive drum, whose potential is made even by the primary charging roller to be ready for the formation of
the next latent image.
F-6-1
6.1.2 Print Process
0014-5001
i-SENSYS MF4150 / i-SENSYS MF4140 / i-SENSYS MF4120 /
The print process shows the basic operation process for image formation by the printer.
The print process of this machine has the main 5 blocks and 7 steps. The toner image is formed on papers by following the steps of each block.
The following is the outline of the blocks and steps of the print process.
F-6-2
1) Electrostatic latent image formation block
Electrostatic images are formed on the photosensitive drum.
Step1: Primary charging (Charges negative potential evenly on the surface of the photosensitive drum)
Step 2: Laser beam exposure (Forms electrostatic images on the photosensitive drum)
2) Developing block
Laser /
scanner block
Cleaner blade
Photosensitive
drum
Primary charging roller
Cartridge
Blade
Developing cylinder
Transfer charging
roller
Fixing film area
DCNT board
Print command
Video signal VDO /VDO
PR1
TRS
DEV
SCNT board
Laser beam
6. Fixing
Drum cleaning
block
3. Devel
opment
Fixing block
Transfer block
Electrostatic latent
image formation block
2. Laser beam exposure
1. Primary charging
Delivery
Flow of paper
Direction of drum rotation
5. Separation
4. Transfer
7. Drum cleaning
Pick-up
Developing block