Canon MF720 Series Service Manual page 40

■ Block 2 : Development
The static latent image formed on the photosensitive drum is visualized by toner deposited in this block.
● Step 3: Development
Toner is deposited on the static latent image formed on the photosensitive drum.
Toner is then charged negatively through friction between the developing cylinder and the developing blade surface. The DC bias
is applied to the developing cylinder to generate potential difference from the photosensitive drum. When the negatively charged
toner contacts the photosensitive drum, it is deposited on the static latent image due to potential difference between the drum
and the developing cylinder.
Unexposed area
■ Block 3 : Transfer
The toner image on the photosensitive drum is transferred to paper through 3 steps in this block.
● Step 4: Primary transfer
Transfer the toner image on the photosensitive drum to the ITB.
The DC positive bias is applied to the primary transfer pad to charge the ITB positively. By this, the negatively charged toner on
the photosensitive drum is transferred to the ITB.
Unexposed area
DC negative bias
Exposed area
Laser beam
Exposed area
Developing cylinder
Photosensitive drum
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2. Technical Explanation
Developing blade
Unexposed area
Exposed area