Canon imageRUNNER 2525 Series Service Manual page 67

Cleaning blade in contact with the photosensitive drum scrapes off the residual toner on its surface without being transferred to
a paper. The residual toner scraped off by the cleaning blade is fed from the toner ejection part into the waste toner box by the
waste toner feed screw. The primary charging roller is cleaned by the brush roller in contact with it.
Toner ejection part
M1
[1]
● Primary Charging Bias Control
The machine is directly charged by the charging roller. DC bias and AC bias that stabilized the charge is applied to the primary
charging roller.
[1]
[2]
● Constant voltage control of DC bias and AC bias
The DC bias and AC bias control circuits on the DC controller PCB control the DC bias and AC bias applied to the primary charging
roller to keep their voltage at the fixed level.
Brush roller
Primary charging roller
No.
Primary charging roller
HVT PCB
Environment sensor
[2] [1]
Primary AC bias
control circuit
No.
Waste toner feed screw
Cleaning Blade
Photosensitive drum
Main motor
Main motor drive signal
Photosensitive drum
Primary DC bias
control circuit
DC Controller PCB
Primary charging bias control signal
Environment sensor detection signal
57
2. Technical Explanation
M 1
[1]
DC Controller PCB
Part name
Part name