Sharp AR-M35 / AR-M450 (serv.man8) Service Manual ▷ View online
AR-350/450 BASIC FUSING SECTION 4-1
[4] FUSING SECTION
1. Composition of fusing section
2. Cleaning roller
The fusing cleaning roller of this machine is made of metal.
1) Remaining toner attaches to the upper heat roller.
1) Remaining toner attaches to the upper heat roller.
2) Due to coating and the temperature characteristics of the upper heat roller, toner is not attached to the upper heat roller but to the lower heat roller.
3) Remaining toner on the lower heat roller is further attached to the cleaning roller due to the temperature characteristics and the difference in
roughness of surfaces of the rollers.
4) Remaining toner attached to the cleaning roller is accumulated until the roller is replaced.
1
Heater lamp 1
Generates heat and transmits heat to the heat roller.The temperature is controlled by the thermistor.
(Temperature control is made mainly on both sides.)
(Temperature control is made mainly on both sides.)
2
Heater lamp 2
Generates heat and transmits heat to the heat roller.The temperature is controlled by the thermistor.
(Temperature control is made mainly on the center.)
(Temperature control is made mainly on the center.)
3
Upper heat roller
Transmits heat to melt toner on paper and fuse toner by means of a pressure with the lower heat roller.
4
Lower heat roller
Fuses toner on paper by means of a pressure with the upper heat roller.
To improve fusing capability, the diameter is greater than the conventional ones. (ø30mm
To improve fusing capability, the diameter is greater than the conventional ones. (ø30mm
→
ø40mm)
5
Fusing upper separation pawl
Prevents winding of paper around the upper heat roller.
6
Fusing lower separation pawl
Prevents winding of paper around the lower heat roller.
7
Thermistor (Center)
Detects the surface temperature of the upper heat roller.
(On/off of heater lamp 1 is controlled according to the detected temperature.)
(On/off of heater lamp 1 is controlled according to the detected temperature.)
8
Thermistor (Side)
Detects the surface temperature of the upper heat roller.
(On/off of heater lamp 2 is controlled according to the detected temperature.)
(On/off of heater lamp 2 is controlled according to the detected temperature.)
9
Thermostat
When an abnormal temperature of the upper heat roller is detected, the heater lamp power is interrupted.
To supply power again, press the switch on the top.
To supply power again, press the switch on the top.
10
Cleaning roller
Cleans toner on the lower heat roller. Made of metal.
!"#$%
AR-350/450 BASIC PROCESS SECTION 5-1
[5] PROCESS SECTION
1. Composition of process section and load voltage
A. Composition of process section
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.
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.
5
MG roller
Forms a magnetic brush with developer and puts toner on the OPC drum. -500V
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.
8
Process thermistor
Detects the temperature in the machine. Process control is performed according to the detected temperature.
9
Developing fuse
Incorporated only in the models of CRU system. Used to detect a new cartridge.
10 CRUM-IC
Toner cartridge conditions (destination, toner motor rotating time, empty, near empty, etc.)
11 Transfer roller
Applies a voltage to transfer toner on the OPC drum to paper.
12 Separation charger
The electrode to separate paper from the OPC drum by the potential difference.
13 Drum separation pawl
The pawl to separate paper from the OPC drum mechanically.
14 Cleaning blade
Made of silicon rubber. Removes remaining toner from the OPC drum. Always in contact with the drum.
15 High voltage resistor PWB
Prevents a high voltage from leaking through the paper guide at a high humidity. 200M
Ω
each.
16 Resist roller
Bends paper to adjust the paper feed timing to the process section.
17 Paper dust cleaner
Removes paper dust from the resist roller to reduce mixing of paper dusts into the process section.
30
-500V
200M
200M
-1.8KV
25 A 45ppm
19 A 35ppm
MAX 5KV
Paper dast clerner
Paper discharge
non contact witn paper
MAX 8KV
constant current
-650V
Fuse
Thermisfor
Thermisfor
opc27 m
ctc27 m
-800V
Toner Sensor
!"#$
AR-350/450 BASIC PROCESS SECTION 5-2
B. Load voltage, current
Load voltage, current name
Default
Remark
MC grid
AE mode
-650V±5V
The main charger voltage in each mode.
Affects the charging level of the OPC drum.
Affects the charging level of the OPC drum.
Text mode
-650V±5V
Text/Photo mode
-650V±5V
Photo mode
-650V±5V
Printer mode
-650V±5V
Fax mode
-650V±5V
Developing
bias
bias
AE mode
-500V±5V
The applied voltage of the MG roller in each mode.
Affects the charging level of toner.
If the charging level of toner is improper, it may cause improper print density or toner splash.
Affects the charging level of toner.
If the charging level of toner is improper, it may cause improper print density or toner splash.
Text mode
-500V±5V
Text/Photo mode
-500V±5V
Photo mode
-500V±5V
Printer mode
-500V±5V
Fax mode
-500V±5V
Developing positive bias
-150V±5V
Used to remove remaining toner from the OPC drum.
Transfer
current
current
Front
35PPM
19µA
The current is used to attract toner on the OPC drum to paper.
Varies depending on the print speed and duplex printing conditions.
Varies depending on the print speed and duplex printing conditions.
45PPM
25µA
Back
35PPM
25µA
45PPM
30µA
Separation
voltage
voltage
Front
-1.8KV±0.1KV
The current is used to separate paper from the OPC drum.
Back
-1.8KV±0.1KV
Transfer voltage
-800V±10V
Used to remove remaining toner from the transfer roller.
% !"#$
AR-350/450 BASIC PROCESS SECTION 5-3
2. Process control
A. List of process correction (image forming section correction) operations
Item
No.
Correction items
Factor
Purpose/Effect
Changed item
Correction base
factor
Correction reset
conditions
1
Photoconductor
characteristics
correction
characteristics
correction
Laser beam
power
correction
power
correction
A decrease in
optical
sensitivity
caused by
photoconducto
r membrane
decrease and
electrical and
optical stress
optical
sensitivity
caused by
photoconducto
r membrane
decrease and
electrical and
optical stress
To correct a decrease in optical
sensitivity caused by
photoconductor membrane
decrease and electrical and
optical stress and to keep the
bright potential at a constant
level, maintaining the proper
density of print.
sensitivity caused by
photoconductor membrane
decrease and electrical and
optical stress and to keep the
bright potential at a constant
level, maintaining the proper
density of print.
Laser beam power
(LD1)
(LD1)
Photoconductor
rotation time
(timer)
rotation time
(timer)
CRU model
Correction is reset
when the IC chip in
the toner hopper is
replaced at toner
replacement. In the
DM series, toner and
the photoconductor
drum cartridge are
replaced together.
SRU model
when the IC chip in
the toner hopper is
replaced at toner
replacement. In the
DM series, toner and
the photoconductor
drum cartridge are
replaced together.
SRU model
Correction is reset
manually by a
serviceman.
manually by a
serviceman.
A change in
photo
sensitivity of
photoconducto
r caused by
changes in the
ambient
temperature
(An increase
in bright
potential due
to degraded
photo
sensitivity
(response
speed) in low
temperature
environment)
photo
sensitivity of
photoconducto
r caused by
changes in the
ambient
temperature
(An increase
in bright
potential due
to degraded
photo
sensitivity
(response
speed) in low
temperature
environment)
To correct a change in photo
sensitivity of photoconductor
caused by changes in ambient
temperatures, maintaining the
proper density of print
(preventing against a fall in the
print density)
sensitivity of photoconductor
caused by changes in ambient
temperatures, maintaining the
proper density of print
(preventing against a fall in the
print density)
Laser beam power
(LD2)/
When the fusing
temperature is 80 C or
below after turning on
the power, the
correction quantity is
calculated for the
temperature in the
machine. When the
fusing temperature is
80 C or above after
turning on the power
and the temperature in
the machine is 30C or
below, the correction
quantity is not revised
and the previous
correction data are
used. If the
temperature in the
machine exceeds 30
C, the correction
quantity is reset.
(LD2)/
When the fusing
temperature is 80 C or
below after turning on
the power, the
correction quantity is
calculated for the
temperature in the
machine. When the
fusing temperature is
80 C or above after
turning on the power
and the temperature in
the machine is 30C or
below, the correction
quantity is not revised
and the previous
correction data are
used. If the
temperature in the
machine exceeds 30
C, the correction
quantity is reset.
Machine
temperature
sensor
temperature
sensor
When the
temperature in the
machine exceeds 30
C, the correction
quantity is reset to 0.
temperature in the
machine exceeds 30
C, the correction
quantity is reset to 0.
Main
charger grid
voltage
correction
charger grid
voltage
correction
A decrease in
dark potential
caused by
photoconducto
r membrane
decrease and
electrical and
optical stress
dark potential
caused by
photoconducto
r membrane
decrease and
electrical and
optical stress
To correct a decrease in dark
potential caused by
photoconductor membrane
decrease and electrical and
optical stress, maintaining the
dark potential on the
photoconductor surface at a
constant level. (Prevention
against background copy)
potential caused by
photoconductor membrane
decrease and electrical and
optical stress, maintaining the
dark potential on the
photoconductor surface at a
constant level. (Prevention
against background copy)
Main charger grid
voltage (Vg1)
voltage (Vg1)
Photoconductor
rotation time
(timer)
rotation time
(timer)
CRU model
Correction is reset
when the IC chip in
the toner hopper is
replaced at toner
replacement. In the
DM series, toner and
the photoconductor
drum cartridge are
replaced together.
SRU model
when the IC chip in
the toner hopper is
replaced at toner
replacement. In the
DM series, toner and
the photoconductor
drum cartridge are
replaced together.
SRU model
Correction is reset
manually by a
serviceman.
manually by a
serviceman.
An increase in
photoconducto
r dark potential
caused by a
change in
ambient
temperature
(high
temperature
environment)
photoconducto
r dark potential
caused by a
change in
ambient
temperature
(high
temperature
environment)
To correct a decrease in
photoconductor dark potential
caused by a change in ambient
temperature, maintaining the
dark potential on the
photoconductor surface at a
constant level. (Prevention
against background copy)
photoconductor dark potential
caused by a change in ambient
temperature, maintaining the
dark potential on the
photoconductor surface at a
constant level. (Prevention
against background copy)
Main charger grid
voltage (Vg2)/
When the fusing
temperature is 80C or
below after turning on
the power, the
correction quantity is
calculated for the
temperature in the
machine.
voltage (Vg2)/
When the fusing
temperature is 80C or
below after turning on
the power, the
correction quantity is
calculated for the
temperature in the
machine.
Machine
temperature
sensor
temperature
sensor
& !"#$
Click on the first or last page to see other AR-M35 / AR-M450 (serv.man8) service manuals if exist.