Transfer Block; Fixing Block; Drum Cleaning Block - Canon imageCLASS LBP6780dn Service Manual

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Technology > Image Formation System > Image Formation Process > Drum cleaning block

■ Transfer block

During the two steps that comprise this block, a toner image on the photosensitive drum is
transferred to the print media.
Step 4: Transfer
The transfer bias is applied to the transfer roller to charge the print media positive. The
positively charged media attracts the negatively charged toner from the photosensitive
drum surface.
Photosensitive
drum
Transfer roller
Transfer bias
2 Technology > Image Formation System > Image Formation Process > Drum cleaning block
Printing paper
F-2-8
Step 5: Separation
The elasticity of the print media and the curvature of the photosensitive drum cause the
media to separate from the drum surface. The static charge eliminator reduces back side
static discharge of the media for stable media feed and image quality.
Photosensitive
drum
Static charge eliminator
Transfer roller

■ Fixing block

The toner image is fixed onto the print media.
Step 6: Fixing
The printer uses an on-demand fixing method. The toner image is permanently affixed to
the print media by heat and pressure. The fixing bias is applied to the fixing film to improve
image quality.
Fixing heater
Brush
Fixing film
Pressure roller

■ Drum cleaning block

2-7
Printing paper
F-2-9
Toner
Printing paper
Fixing bias
F-2-10
2-7