Controls - Canon MF8580Cdw Service Manual

2
Technical Overview > Image Formation System > Controls > High-voltage power supply control

Controls

■ High-voltage power supply control
● Overview
The high-voltage power supply PCBs are to apply high-voltage bias to the primary charging
roller, the primary transfer pad, the secondary transfer external roller, and the ITB cleaning
unit. Such high-voltage bias is generated through control by the DC controller on the high-
voltage power supply PCBs.
The figure below shows the high-voltage power source schematically.
Type Bias applied
Primary charging Charge the photosensitive drum
DC negative
bias surface negatively.
Deposit toner on the static latent
Developing bias DC negative image formed on the photosensitive
drum.
Adjust the charged toner amount on
Blade bias DC negative
the developing cylinder.
Primary transfer Transfer the toner image on the
DC negative
bias photosensitive drum to the ITB.
Transfer the toner image on the ITB
DC positive
to the paper.
Secondary transfer
bias
Clean the secondary transfer
DC negative
external roller.
ITB cleaning brush Charge the toner on the ITB
DC positive
bias positively.
ITB cleaning roller Charge the toner on the ITB
DC positive
bias positively.
2 Technical Overview > Image Formation System > Controls > High-voltage power supply control
Purpose Applied to
Primary charging roller
(cartridge)
Developing cylinder
(cartridge)
Developing blade
(cartridge)
Developing blade
(cartridge)
Secondary transfer
external roller
ITB cleaning brush
ITB cleaning roller
T-2-12
Primary charging
Developing bias
bias circuit
circuit
Cartridge
Photosensitive drum
Primary transfer pad
ICLB
ICLR
ITB
??
cleaning unit
Secondary transfer
external roller
ITB cleaning brush ITB cleaning roller Secondary transfer
bias circuit bias circuit
DC controller
2-23
Blade bias circuit
Primary transfer
bias circuit bias circuit
High-voltage power supply
F-2-28
2-23