Canon imageRUNNER 2525 Series, Service Manual, Page: 69 / 402

[3]
Density Setting
Main Controller PCB
Photosensitive drum
Developing cylinder
[2]
Environment sensor
[1]
HVT PCB
Developing AC bias
control circuit
DC Controller PCB
Developing DC bias
control circuit
No. Part name
[1] Developing bias control signal
[2] Environment sensor detection signal
[3] Density setting signal
● 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 developing
cylinder to keep their voltage at the fixed level.
● DC bias switch control
The DC bias output varies according to the environment or density setting detected by the environment sensor (HU1).
■ Toner Container
● Outline
Toner cartridge is filled with toner and supplies to the drum unit.
Toner cartridge
The toner in the toner cartridge is fed to the sub hopper and then to the developing unit by the toner feed screw. The toner
presence/absence in the sub hopper is detected by the sub hopper toner sensor (TS2) which is a magnetic permeability sensor.
2. Technical Explanation
59