Canon MF720 Series Service Manual page 39

Block
1 Static latent image
forming
2 Development
3 Transfer
4 Fixing
5 ITB cleaning
6 Drum cleaning
7. Fixing
6. Separation
5. Secondary transfer
Registration
■ Block 1 : Static latent image forming block
This block consists of 2 steps to form a static latent image on the photosensitive drum.
● Step 1: Primary charging
Before forming a static latent image, the photosensitive drum surface should be charged negatively.
This product employs the method to charge the photosensitive drum directly from the primary charging roller, applying the DC
negative bias in order to negatively charge the photosensitive drum surface.
● Step 2: Laser beam exposure
Expose the photosensitive drum with laser beams to form a static latent image.
The static latent image is formed by laser beam scanning that neutralizes or strips negative potentials on the scanned parts.
Step
1 Primary charging
2 Laser beam exposure
3 Development
4 Primary transfer
5 Secondary transfer
6 Separation
7 Fixing
8 ITB cleaning
9 Drum cleaning
Delivery
Fixing block
Static image formation block
2. Laser beam exposure
Development
1. Primary charging
block
3. Development
Drum cleaning block
ITB cleaning
9. Drum cleaning
block
8. ITB cleaning
Transfer block
Pickup
Primary charging roller
Photosensitive drum
Charge the photosensitive drum surface negatively.
Form a static latent image on the photosensitive drum.
Deposit toner to visualize the static latent image.
Transfer the toner image on the photosensitive drum to the ITB.
Transfer the toner image on the ITB to the paper.
Separate the paper from the ITB.
Fix the toner image on the paper.
Clean the residual toner on the ITB.
Clean the residual toner on the photosensitive drum.
Flow of paper
Rotation of ITB/photosensitive drum
Block
Step
DC bias
31
2. Technical Explanation
Description