Brother MFC-9420CN Service Manual page 42

(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
Charging
OV
OPC Belt Surface
-CBV
-V0
-CHV
-CBV
Latent Image
-V0 -V0
-V0 -V0
-V0
-V0 -V0
brother
-V0
-V0 -V0
-V0 -V0
-V0
-V0
Laser Diode
Exposing
-VR
Dev Roller
OPC Charger Roller PU
Fig. 3-11
3 - 1 0
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(V) in the charging process.
0
Toner Image
-V0
-V0 -V0 -V0
-V0
-V0
brother
-V0
-V0
-V0 -V0 -V0 -V0
brother
K Y M C
Developing
Transfer Belt
-DBV
(M)TONER
-DBV
-V0 -CBV
-CBV
-CBV
-CBV
Blade
Erase Lamp
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