Service manual

FO-IS125N
3 – 5
7. Print process
7.1. Image forming process
Normal paper is used as print paper. A laser beam is used to expose
on the OPC surface to form latent electrostatic images, which are
developed into visible images (toner images) and are transferred on
paper. The basic operation is composed of the five processes: charg-
ing, exposure, development, transfer, and cleaning.
7.2. System diagram (1)
7.3. System diagram (2)
Fig. 7
Main
charger
brush
Separation
electrode
Transfer
charge
roller
Developing roller
Supply roller
Photoconductor
drum (OPC)
Laser Scanning Unit
Laser
beam
DC: +3600V (D6 Cathode)
DC: -950V
AC: -570V <--> -1330V
DC: -500V
DC: +300V
DC: -400V
Paper
Toner
MC
TC
SV
DV
DC: -200V
Heat roller
Pressure roller
Heater lamp
FU-EARTH
Print
print
Cleaning
cleaning
Paper
100MOHM
100V
4.7MOH M 4.7MOHM
Transfer Charger
Roller Voltage
Development
Roller
Voltage
Main Charger
brush Voltage
High Voltage Power Supply Unit
Supply
Roller
Voltage
IC100
CONTROL PWB
FAX
ENGINE
22
21
TCON
MCON
PWMSIN
Constant
voltage
control
circuit
PWM
control
circuit
Logic
circuit
Oscillation
circuit
B51
Transformer
High Voltage PWB Unit
Constant
voltage
control
circuit
Oscillation
circuit
Feedback circuit
Feedback circuit
B1
Transformer
HV(+)
Rectifier
circuit
HV(-)
Rectifier
circuit
HV(-)
Rectifier
circuit
Constant
voltage(+)
circuit
Constant
voltage(-)
circuit
Short
circuit
Short
protection
circuit
SV
DV
MC
TC
110MΩ
250MΩ
FU-EARTH
LASER MFP
Transfer Roller
Supply Roller
Developing Roller
Charger Roller
Heat Roller
Pressure Roller
Doctor
OPC DRUM
Separation electrode
27
Fig. 8