Canon I-Sensys LBP5050, Service Manual

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Chapter 2
2-4
F-2-4
2.4.1.3 Latent image formation block
0018-6680
LBP5050N / LBP5050
During the two steps that comprise this block, an invisible latent image is formed on the photosensitive drum.
Step 1: Primary charging
To prepare for latent image formation, the surface of the photosensitive drum is charged with a uniform negative potential.
The primary charging roller charges the photosensitive drum directly. The DC negative bias is applied to the primary charging roller to keep a negative potential
on the drum surface.
F-2-5
Step 2: Laser-beam exposure
The laser beam scans the photosensitive drum to neutralize the negative charge on portions of the drum surface. An electrostatic latent image forms where the
negative charge was neutralized.
F-2-6
2.4.1.4 Development block
0018-6681
LBP5050N / LBP5050
Latent image formation
Transfer
Fixing
Development
Pickup
Registration
5. Secondary transfer
6. Separation
7. Fixing
Delivery
4. Primary transfer
2. Laser-beam exposure
3. Development
8. ITB cleaning 9. Drum cleaning
1. Primary charging
: Media path
: Direction of drum rotation
: Block
: Step
Photosensitive drum cleaning ITB cleaning
DC bias
Photosensitive drum
Primary charging roller
Laser beam
Unexposed area Exposed area