Brother MFC-9420CN Service Manual page 44

(2) Variation of OPC Belt Potential (See Fig.3-11.)
1) The OPC belt is initially biased to -CBV(V).
2) The OPC belt surface is evenly charged to V
3) 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.
4) 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) (the latent image)
and -DBV(V), and a visible toner image is formed as the result.
5) 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.
6) The OPC belt is discharged by the erase lamp.
-CBV
-CBV
-CBV
-CBV
OPC Belt
OV
OPC Belt Surface
-CBV
-V0
-CHV
-CBV
Latent Image
-V0
-V0
-V0
-V0
-V0
-V0
brother
-V0 -V0
-V0
-V0
-V0
-V0
Laser Diode
Charging
Exposing
-VR
OPC Charger Roller PU
Fig. 3-11
3 - 1 0
(V) in the charging process.
0
Toner Image
-V0 -V0 -V0
-V0
-V0
-V0
brother
-V0
-V0
-V0 -V0 -V0
-V0
K Y M C
Developing
-DBV
Dev Roller
-DBV
-V0 -V0
-CBV
-CBV
-CBV
-V0 -CBV
brother
Erase Lamp
Transfer Belt
(M)TONER
Confidential
Blade