Development Block; Transfer Block - Canon imageCLASS MF4890dw Service Manual

2
Technical Overview > Image Formation System > Overview/Configuration > Transfer Block

■ Development Block

This block is comprised of one step; it puts toners to the static latent images on the surface of
the photosensitive drum and visualizes the images using toner projection development. The
toner projection development makes the toner jump on the surface of the photosensitive drum
and develops the images.
The toner (developer) used for this equipment is a one-component toner that comprises
magnetic body and resin, etc.
Step 3: Development
Toner is affixed to static latent images on the surface of the photosensitive drum.
The toner is charged negatively by friction between the developing cylinder and the surface of
the developing blade.
An area on the photosensitive drum exposed with laser beam has higher potential than the
developing cylinder; the potential difference between the drum surface and the cylinder
enables the toner to jump on the drum surface and makes them visible images.
AC bias superimposed with the development DC negative bias is applied to the developing
cylinder.
Blade
Developing cylinder
Exposed area
Unexposed
area
Photosensitive drum
2 Technical Overview > Image Formation System > Overview/Configuration > Transfer Block
AC bias
Unexposed area
Exposed area
DC bias
F-2-21

■ Transfer Block

This block is comprised of two steps; it transfers toner images on the surface of the
photosensitive drum to papers.
Step 4: Transfer
In this step, toner images on the photosensitive drum are transferred to papers.
This equipment applies DC positive bias to the transfer roller facing the photosensitive drum
and charges papers positively. This enables toner negatively charged on the surface of the
photosensitive drum to be transferred to papers.
Photosensitive
drum
Transfer roller
2-17
Media
DC bias
F-2-22
2-17