Brother HL-3450CN Service Manual page 64

(2) Variation of OPC Belt Potential (See Fig.4-10.)
i) The OPC belt is initially biased to -CBV (V).
ii) The OPC belt surface is evenly charged to V
iii) The potential of the exposure part of the OPC belt is reduced to -VR (V) as it is
exposed to the laser beam in the process of exposing, and an electrostatic latent
image is formed on the OPC belt as the result.
iv) Negatively charged toner is moved onto the exposed part of the OPC belt in the
development process due to the difference of potential between -VR (V) and -DBV
(V), and a visible toner image is formed as the result.
v) Negatively charged toner on the OPC belt moves to the transfer drum surface in the
transfer process because the GND potential of the transfer drum is greater than -
VR (V) of the OPC belt.
vi) The OPC belt is discharged by the erase lamp.
1
Process
OV
- CBV
OPC Belt
- V
O
CHV
CBV
2 3 4
Transfer Drum
GND
Toner
- V
R
Toner
DBV
Dev. roller
1
Charging Process
2
Exposing Process
3 Developing Process
Charger
4
Transfering Process
5
Cleaning (Erase)
DBV
CBV
CHV
DBV
- VR
Fig. 4-10
4-11
(V) in the charging process.
0
5
Power Supply for OPC Belt Bias
Power Supply for Charging
Power Supply for Dev. Roller Bias
Remain voltage on the OPC Belt
HL-3450CN SERVICE MANUAL