Sharp AR-M351U / AR-M451U (serv.man11) Service Manual ▷ View online
AR-M351U/M451U, AR-M355U/M455U MAINTENANCE AND DETAILS OF EACH SECTION 7 - 4
[DETAILS OF EACH SECTION]
1. Process section
A. General
Toner is attached to electrostatic latent images formed by the
laser beams which were radiated to the OPC drum charged by the
main charger, forming toner images.
laser beams which were radiated to the OPC drum charged by the
main charger, forming toner images.
The toner images formed on the OPC drum are transferred to
paper by the transfer roller.
paper by the transfer roller.
No.
Name
Operation
1
Toner cartridge
Supplies toner to the developing unit, and collects waste toner.
2
Developer unit
Mixes toner and carrier, and attaches toner to electrostatic latent images to form visible
images.
images.
3
Transfer roller
Transfers toner images to the OPC drum.
4
Process drum unit
Forms images (electrostatic latent images, visible images) on the OPC drum.
5
Main charger unit
Charges the OPC drum surface negatively and evenly.
AR-M351U/M451U, AR-M355U/M455U MAINTENANCE AND DETAILS OF EACH SECTION 7 - 5
Process Section Composition and Applying Voltage
Composition of process section
30
-500V
(-470)
(-470)
200M
200M
25
µ
A (45ppm)
19
µ
A (31/35ppm)
-1.8KV
MAX 5KV
Paper dust cleaner
Separation electrode
MAX 8KV
constant current
-650V
(-620V)
(-620V)
Temperature/humidity sensor
opc27 m
ctc27 m
-800V
Toner density sensor
14
14
8
7
1
9
6
2
4
3
13
12
11 10
16
15
5
1
Laser beam
Forms latent electrostatic images on the photoconductor drum. (Writing resolution: 600dpi)
The output from LSU can be set with the simulation. (Basically the initial setup is used.)
The output from LSU can be set with the simulation. (Basically the initial setup is used.)
2
Photoconductor drum
Latent electrostatic images are formed on the photoconductor drum. It attracts toner to the
electrostatic images and transfers them to paper. An OPC drum of 30mm diameter is employed.
electrostatic images and transfers them to paper. An OPC drum of 30mm diameter is employed.
3
Main charger
Applies a high voltage to charge the OPC drum. Of saw teeth type.
4
Screen grid
Charges electric charges generated from the main charger to the OPC drum evenly. -650V, 35cpm
Copy, -620V only for AE.
Copy, -620V only for AE.
5
MG roller
Forms a magnetic brush with developer and puts toner on the OPC drum. -500V, 35cpm
Copy, -470V only for AE.
Copy, -470V only for AE.
6
Developing doctor
Keeps the thickness of developer and toner (magnetic brush) on the MG roller at a constant level.
7
Toner quantity sensor
Detects the quantity of toner in the developing unit. A magnetic sensor of transmission type is
employed.
employed.
8
Temperature/humidity sensor
The temperature and the humidity inside the machine are detected, and process control is
performed according to the detected temperature and humidity.
performed according to the detected temperature and humidity.
9
CRUM-IC
Toner cartridge conditions (destination, toner motor rotating time, empty, near empty, etc.)
10
Transfer roller
Applies a voltage to transfer toner on the OPC drum to paper.
11
Separation electrode
The electrode to separate paper from the OPC drum by the potential difference.
12
Drum separation pawl
The pawl to separate paper from the OPC drum mechanically.
13
Cleaning blade
Made of silicon rubber. Removes remaining toner from the OPC drum. Always in contact with the
drum.
drum.
14
High voltage resistor PWB
Prevents a high voltage from leaking through the paper guide at a high humidity. 200M
Ω
each.
15
Resist roller
Bends paper to adjust the paper feed timing to the process section.
16
Paper dust cleaner
Removes paper dust from the resist roller to reduce mixing of paper dusts into the process section.
AR-M351U/M451U, AR-M355U/M455U MAINTENANCE AND DETAILS OF EACH SECTION 7 - 6
[OPC drum section]
A. General
In this section, laser beams are radiated to the OPC drum surface
which was negatively charged, making electrostatic latent images.
which was negatively charged, making electrostatic latent images.
B. Major parts and signal functions
DM
PSPS
+24V1
PSPS\
1
1
2
2
PHNR-02-H+BU02P-TR-P-H
8FE-BT-VK-N
DSW-L
DM-T
DM\
5
6
DSW-L
GND1
3
2
1
4
GND1
DMCLK\
(NC)
8
7
PCU PWB
1
2
3
4
5
6
7
8
DM-T
GND2
DM\
CN6
GND2
DSW-F
DSW-F
DMCLK\
9604S-08C
(NC)
1
2
3
4
5
6
7
8
CN5
+24V1
CRUCLK
+5VCRU
GND2
CRUSDA
PSPS\
(NC)
B8B-PH-K-S
+24V1
1
DVREM\
DHVREM
MHVREM\
THV+PWM\
6
4
13
14
12
GND2
3
7
8
9
10
5
GBPWM\
11
CN15
DSW-F
THin
DHVPWM\
THV-PWM\
THVREM\
2
DVPWM\
9604S-14F
GND2
MHV-T
RD
GR
BL
YL
WH
HV
1
DVREM\
DHVREM
MHVREM\
THV+PWM\
6
4
13
14
12
GND2
3
7
8
9
10
5
GBPWM\
11
DSW-F
THin
DHVPWM\
THV-PWM\
THVREM\
2
DVPWM\
1-84432-4(AMP)
GND2
MHV-T
PS-187
SRA-21T-4L
BIAS
PS-187
PS-187
PS-187
WH
WH
MHV
THV
GB
DHV
DV
RD
PS-187
SRA-21T-3
SRA-21T-4L
RD
SRA-21T-3
8
3
1
2
2
5
4
9
7
6
Code
Signal
name
Name
Function/Operation
Type
Note
DM
DM
OPC drum motor
Drives the OPC drum and the transfer section.
DC brushless motor
PSPS
PSPS
Drum separation pawl solenoid
Drives the OPC drum separation pawl
Solenoid
No.
Name
Operation
1
OPC drum
Forms electrostatic latent images by laser beams.
2
Drum separation pawl
Separates paper from the drum.
3
Sub blade (Cleaning seal)
Prevents against toner leakage from the cleaner section.
4
Screen grid
Helps to charge the OPC drum evenly with electric charges provided from the main charger.
5
Saw-teeth charger
Applies a high voltage to charge the OPC drum.
6
Separation pawl oscillation shaft
Moves in the front and rear frame direction to install the separation pawl.
7
Cleaning blade
Cleans remaining toner on the OPC drum.
8
Waste toner transport pipe
Transports toner from the cleaner unit to the waste toner box in the toner cartridge front section.
9
Cleaning unit
Saw teeth charger is cleaned.
AR-M351U/M451U, AR-M355U/M455U MAINTENANCE AND DETAILS OF EACH SECTION 7 - 7
C. Operational descriptions
The OPC drum surface is negatively charged by the main charger.
The laser beam images are radiated to the OPC drum surface by
the laser unit to form latent electrostatic images.
The laser beam images are radiated to the OPC drum surface by
the laser unit to form latent electrostatic images.
1) The OPC drum surface is negatively charged by the main
charger.
The main charger grid is provided with the screen grid. The
OPC drum is charged at a voltage virtually same as the volt-
age applied to the screen grid.
OPC drum is charged at a voltage virtually same as the volt-
age applied to the screen grid.
2) LED lights are radiated to the OPC drum surface by the laser
unit to form latent electrostatic images.
When LED lights are radiated to the OPC drum CGL, negative
and positive charges are generated.
and positive charges are generated.
Positive charges generated in CGL are attracted to the nega-
tive charges on the OPC drum surface. On the other hand,
negative charges are attracted to the positive charges in the
OPC drum aluminum layer.
tive charges on the OPC drum surface. On the other hand,
negative charges are attracted to the positive charges in the
OPC drum aluminum layer.
Therefore, positive charges and negative charges are bal-
anced out on the OPC drum and in the aluminum layer, reduc-
ing positive and negative charges to decrease the OPC drum
surface voltage.
anced out on the OPC drum and in the aluminum layer, reduc-
ing positive and negative charges to decrease the OPC drum
surface voltage.
Electric charges remain at a position where LED lights are not
radiated.
radiated.
As a result, latent electrostatic images are formed on the OPC
drum surface.
drum surface.
3) After transfer operation, remaining toner is removed by the
cleaning blade.
Residual toner removed from the OPC drum surface is trans-
ported to the recycle toner collection section in the toner car-
tridge by the waste toner transport screw.
ported to the recycle toner collection section in the toner car-
tridge by the waste toner transport screw.
4) All the surface of the OPC drum is discharged by laser beams.
After completion of the job, laser beams are radiated onto al
the surface of the OPC drum.
When laser beams are radiated onto the CGL of the OPC
drum, positive and negative charges are generated.
the surface of the OPC drum.
When laser beams are radiated onto the CGL of the OPC
drum, positive and negative charges are generated.
Positive charges generated in CGL are attracted to the nega-
tive charges on the OPC drum surface. On the other hand,
negative charges are attracted to positive charges in the alu-
minum layer of the OPC drum.
tive charges on the OPC drum surface. On the other hand,
negative charges are attracted to positive charges in the alu-
minum layer of the OPC drum.
Therefore, positive and negative charges are balanced out on
the OPC drum surface and in the aluminum layer, reducing
positive and negative charged to decrease the surface voltage
of the OPC drum.
the OPC drum surface and in the aluminum layer, reducing
positive and negative charged to decrease the surface voltage
of the OPC drum.
Aluminum
layer
OPC drum
CTL
CGL
High voltage unit
Main corona unit
Screen grid
OPC drum
LED lights
Aluminum
layer
OPC drum
CGL
CTL
Drum
LED lights
CLT
CGL
Aluminum
layer
Aluminum
layer
CLT
CGL
CGL
