Okidata OKIPAGE 14e Maintenance Manual
OKIPAGE 14e
LED Page Printer
Maintenance Manual
ODA / OEL / INT
2001-03-19 Rev.2
41605601TH Rev.2 1 / 182
Document Revision History
Rev.No. Date
No.
1 2000-12-08 ISSUE ODC Miyashita
2 2001-03-19 NP39 H Ono
Corrected items
Page Description of change
Person in
charge
41605601TH Rev.2 2 /
PREFACE
This Maintenance Manual describes the field maintenance methods for OKIPAGE 14e LED Page Printers.
This manual is written for use by the maintenance personnel. Please note that you should refer to the
Printer Handbook and Printer Setup for the handling and operating methods of the equipment.
41605601TH Rev.2 3 /
Contents
1. CONFIGURATION ............................................................................................... 7
1.1 System Configuration ................................................................................... 7
1.2 Printer Configuration..................................................................................... 8
1.3 Optional Configuration .................................................................................. 9
1.4 Specification ................................................................................................11
1.5 Safety Standards ........................................................................................ 13
1.5.1 Certification Label .................................................................................................... 13
1.5.2 Warning Label.......................................................................................................... 13
1.5.3 Warning/Caution Marking ........................................................................................ 14
2. OPERATION DESCRIPTION ............................................................................. 15
2.1 Main Control Board..................................................................................... 17
2.2 Power Supply/Sensor Board....................................................................... 18
2.3 Electrophotographic Process...................................................................... 20
2.3.1 Electrophotographic Process Mechanism ............................................................... 20
2.3.2 Electrophotographic Process................................................................................... 22
2.3.3 Process Operation Descriptions .............................................................................. 25
2.4 Paper Jam Detection .................................................................................. 35
2.5 Cover Open ................................................................................................ 37
2.6 Toner Low Detection ................................................................................... 38
3. PARTS REPLACEMENT.................................................................................... 40
3.1 Precautions for Parts Replacement ............................................................ 40
3.2 Parts Layout................................................................................................ 42
3.3 How to Change Parts.................................................................................. 45
3.3.1 Upper Cover Assy.................................................................................................... 46
3.3.2 IC Card Cover.......................................................................................................... 47
3.3.3 LED Head ................................................................................................................ 48
3.3.4 Operator Panel Assy................................................................................................ 49
3.3.5 Lower Base Unit ...................................................................................................... 50
3.3.6 Pulse Motor (Main/Drum) ........................................................................................ 51
3.3.7 Pulse Motor (Registration) ....................................................................................... 52
3.3.8 Face Up Stacker Assy ............................................................................................. 53
3.3.9 Eject Roller Assy...................................................................................................... 54
3.3.10 Motor Assy............................................................................................................... 55
3.3.11 Hopping Roller Shaft Assy....................................................................................... 56
3.3.12 Stacker Cover Assy ................................................................................................. 57
3.3.13 Registration Roller ................................................................................................... 58
3.3.14 Roller Transfer Assy ................................................................................................ 59
3.3.15 Fusing Unit .............................................................................................................. 60
3.3.16 Back-up Roller ......................................................................................................... 61
3.3.17 Sensor Plate (Inlet).................................................................................................. 62
3.3.18 Sensor Plate (Outlet), Sensor Wire Assy................................................................. 63
3.3.19 Manual Feed Guide Assy ........................................................................................ 64
3.3.20 Sensor Plate (Paper Supply) ................................................................................... 65
3.3.21 M7G-PCB ................................................................................................................ 66
3.3.22 Power Supply/Sensor Board, High Voltage Unit and Contact Assy......................... 67
3.3.23 Cassette Guide L Assy ............................................................................................ 68
3.3.24 Cassette Guide R Assy............................................................................................ 69
3.3.25 Spacer Bearing (L/R)............................................................................................... 70
4. ADJUSTMENT ................................................................................................... 71
4.1 Adjustment Types and Functions................................................................ 71
4.1.1 Status Monitor ......................................................................................................... 71
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4.1.2 Engine Maintenance Utility ...................................................................................... 71
4.2 Adjustment When Replacing a Part............................................................ 72
4.2.1 Setting of LED Head Drive Time.............................................................................. 72
4.2.2 Uploading and Downloading EEPROM Data .......................................................... 73
5. PERIODICAL MAINTENANCE........................................................................... 74
5.1 Periodical Replacement Parts .................................................................... 74
5.2 Cleaning...................................................................................................... 74
5.2.1 Cleaning of LED Lens Array .................................................................................... 74
6. TROUBLESHOOTING PROCEDURES............................................................. 76
6.1 Troubleshooting T ips................................................................................... 76
6.2 Check Points Before Correcting Image Problems ...................................... 76
6.3 Notes When Correcting Image Problems ................................................... 76
6.4 Preparation Before Troubleshooting ........................................................... 76
6.5 Troubleshooting .......................................................................................... 78
6.5.1 Status Monitor Message List ................................................................................... 78
6.5.2 Status Message Troubleshooting ............................................................................ 82
6.5.3 Image Troubleshooting ............................................................................................ 90
7. WIRING DIAGRAM ........................................................................................... 99
7.1 Interconnect Signal Diagram ...................................................................... 99
7.2 PCB Layout and Connector Signal List .................................................... 100
7.3 Resistance Check......................................................................................110
8. PARTS LIST ......................................................................................................112
Appendix A RS-232C SERIAL INTERFACE (option).........................................119
Appendix B CENTRONICS PARALLEL INTERFACE....................................... 121
Appendix C UNIVERSAL SERIAL BUS (USB).................................................. 125
Appendix D MAINTENANCE UTILITY GUI MANUAL....................................... 129
1. Overview .................................................................................................... 129
1.1 System Requirements ............................................................................................... 129
2. Utility Starting-Time Operation ................................................................... 129
3. Main Set Property Sheet ............................................................................ 130
3.1 Printer Status Group.................................................................................................. 130
3.2 LED Head Marking No............................................................................................... 133
3.3 Descriptions on Buttons............................................................................................. 134
4. Menu Property Sheet................................................................................ 136
4.1 Setting Items.............................................................................................................. 137
5. Local Print Property Sheet ......................................................................... 140
6. Product Set Property Sheet........................................................................ 142
7. About Property Sheet ................................................................................. 143
8. For Invalid Events....................................................................................... 144
8.1 Failed Printer Setting ................................................................................................. 144
8.2 RAM Check Error....................................................................................................... 144
Appendix E MULTI-PURPOSE FEEDER.......................................................... 134
1. OUTLINE.................................................................................................... 145
1.1 Functions ................................................................................................................... 145
1.2 External View and Component Names...................................................................... 145
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2. MECHANISM DESCRIPTION.................................................................... 146
2.1 General Mechanism .................................................................................................. 146
2.2 Hopper Mechanism ................................................................................................... 146
3. PARTS REPLACEMENT............................................................................ 147
3.1 Precautions Concerning Parts Replacement............................................................. 147
3.2 Parts Layout .............................................................................................................. 149
3.3 Parts Replacement Methods ..................................................................................... 150
3.3.1 Link ................................................................................................................ 151
3.3.2 Separator....................................................................................................... 152
3.3.3 OLEV-11-PCB ............................................................................................... 153
3.3.4 Pulse Motor ................................................................................................... 154
3.3.5 Planet Gear ................................................................................................... 155
3.3.6 Roller-A and B ............................................................................................... 156
4. TROUBLESHOOTING ............................................................................... 157
4.1 Precautions Prior to the Troubleshooting .................................................................. 157
4.2 Preparations for the Troubleshooting ........................................................................ 157
4.3 Troubleshooting Method............................................................................................ 158
4.3.1 LED Status Message List .............................................................................. 158
5. CONNECTION DIAGRAM ......................................................................... 160
5.1 Interconnection Diagram ........................................................................................... 160
5.2 PCB Layout ............................................................................................................... 160
6. PARTS LIST ............................................................................................... 161
Appendix F HIGH CAPACITY SECOND PAPER FEEDER MAINTENANCE ... 163
1. OUTLINE.................................................................................................... 163
1.1 Functions ................................................................................................................... 163
1.2 External View and Component Names...................................................................... 163
2. MECHANISM DESCRIPTION.................................................................... 164
2.1 General Mechanism .................................................................................................. 164
2.2 Hopper Mechanism ................................................................................................... 164
3. PARTS REPLACEMENT............................................................................ 165
3.1 Precautions Concerning Parts Replacement............................................................. 165
3.2 Parts Layout .............................................................................................................. 167
3.3 Parts Replacement Methods ..................................................................................... 168
3.3.1 Stepping Motor (Hopping) ............................................................................. 169
3.3.2 TQSB-2 PCB ................................................................................................. 171
3.3.3 Hopping Roller Shaft Assy and One-way Clutch Gear.................................. 171
4. TROUBLESHOOTING ............................................................................... 172
4.1 Precautions Prior to the Troubleshooting .................................................................. 172
4.2 Preparations for the Troubleshooting ........................................................................ 172
4.3 Troubleshooting Method............................................................................................ 173
4.3.1 LED Status Message List .............................................................................. 173
5. CONNECTION DIAGRAM ......................................................................... 175
5.1 Interconnection Diagram ........................................................................................... 175
5.2 PCB Layout ............................................................................................................... 175
6. PARTS LIST ............................................................................................... 176
41605601TH Rev.2 6 /
1. CONFIGURATION
1.1 System Configuration
OKIPAGE 14e consists of control and engine blocks in the standard configuration, as shown in Figure
1-1.
In addition, the options marked with asterisk(*) are available.
Operator Panel
Paper
Cassette
*High Capacity
Second Paper
Feeder
Paper Feeding Mechanism
(First Tray Unit)
Engine Unit
Face Up
Stacker
Face
*Multi Purpose
Feeder
Centronics
USB
Electrophotographic
Processing Unit
Fuser Unit
Main Control Board
Down
Stacker
High Voltage Unit
and Sensor Board
Power Supply
AC
* : Optional
RS-232C
Expansion Board
1 DRAM SIMM Socket
1 Flash SIMM Socket
or
RS-232C Serial*
Interface Board
1 DRAM SIMM Socket
1 Flash SIMM Socket
DRAM SIMM*
Flash SIMM*
(Flash memory)
Figure 1-1
41605601TH Rev.2 7 /
1.2 Printer Configuration
The printer unit consists of the following hardware components:
• Electrophotographic Processor
• Paper Feeder
• Controller
• Operator Panel
• Power Supply Unit
The printer unit configuration is shown in Figure 1-2.
Upper cover
Operator panel assy
Stacker assy
Optional board
Toner-cartridge(Type 5)
(consumable)
Fusing unit
Image drum unit(Type 8)
(consumable)
Legal/universal paper cassette
Power supply
Main control board
High Voltage Unit/sensor board
Figure 1-2
41605601TH Rev.2 8 /
1.3 Optional Configuration
The options shown below are available for use with OKIPAGE 14e. These are available separately
from the printer unit.
(1) High Capacity Second Paper Feeder
(2) Multi Purpose Feeder
(3) Expansion Board
41605601TH Rev.2 9 /
(4) RS-232C Serial Interface Board
(5) DRAM SIMM Memory
DRAM SIMM memory is available with memory of 8MB,16MB,32MB [Oki Data genuine].
The access time of SIMM memories are 60ns, 70ns, 80ns, and 100ns.
(6) Flash SIMM
Flash SIMM is available with memory of 4MB, 8MB and 16MB.
41605601TH Rev.2 10 /
1.4 Specification
(1) Type Desktop
(2) External dimensions Height 7.9” (200 mm)
(3) Weight Approx. 9 kg
(4) Developing method Dry electrophotography
Exposing method LED stationary head
(5) Paper used <Type>
Width 13.0” (330 mm)
Depth 15.6” (395 mm)
• Standard paper
– Xerox 4200 (20 lbs)
• Application paper (manual face-up feed)
– Label
– Envelope
– OHP paper (transparency)
<Size>
• Standard sizes
– Letter
– Legal* [*Without Multi Purpose Feeder (Option)]
– Legal-13*
– Executive
– COM-10** [**manual feed and Multi Purpose Feeder
(Option) only]
– Monarch**
– DL**
– C5**
– A4
– A5
– B5 (JIS)
– A6
• Applicable sizes
– Width: 3.4” to 8.5” (86 to 216 mm)
– Length: 5.5” to 14” (140 to 355.6 mm)
<Thickness>
– Automatic feed: 16 to 28 lbs (60 to 105 g/m2)
– Manual feed: Label, OHP paper (transparency)
Envelope (24 to 28lbs)
(6) Printing speed Continuous printing: 14 pages per minute with Letter size
paper. [Except Multi purpose Feeder
(10.7ppm)]
Warm-up time: 45 seconds typical at room temperature
[68˚F (20˚C), AC 120/230 V].
First page print time: 7.5 seconds typical for the Letter size
paper after warm-up.
(7) Paper feeding method Automatic feed or manual feed
(8) Paper delivery method Face down/face up
(9) Resolution 300 × 300 dots/inch
300 × 1200 dots/inch
41605601TH Rev.2 11 /
(10)Power input 120 V + 6%, –15%
230 VAC ± 10%
(11)Power consumption 120VAC 230VAC
Peak : Approx. 600W Approx. 600W
Typical operation : Approx. 340W Approx. 340W
Idle : Approx. 75W Approx. 66W
Power save mode : Approx. 10W Approx. 11W
(12)Temperature and humidity
In operation Power off mode During Storage Unit
Temperature
Humidity
Maximum wet bulb
temperature
Minimum difference
between wet and dry
50-90
(10-32)
20-80
77
(25)
35.6
(2)
32-110
(0-43)
10-90
80.4
(26.8)
35.6
(2)
14-110
(–10-43)
10-90
˚F
(˚C)
%RH
˚F
(˚C)
˚F
(˚C)
bulb temperatures
1. Storage conditions specified above apply to printers in packed condition.
2. Temperature and humidity must be in the range where no condensation occurs.
Temperature
(
°
C)
32
28
Operation range
10
20 80
Humidity (%)
(13) Noise During operation : 53 dB (A) or less
Standby : 38 dB (A) or less
Quiet mode : Back ground level
(14) Consumables Toner cartridge kit ODA : 2,000 (5% duty)
OEL/INT : 2,500 (5%duty)
Image drum cartridge 20,000 (at continuouts printing)
14,000 (3 page/job) without Power Save
9,000 (1 page/job) without Power Save
8,000 (1 page/job) without Power Save
(Minimum)
41605601TH Rev.2 12 /
1.5 Safety Standards
1.5.1 Certification Label
The safety certification label is affixed to the printer in the position described below.
ODA AC : 120V model ODA AC : 230V model
INT AC : 230V model
1.5.2 Warning Label
The warning labels are affixed to the sections which may cause bodily injury.
Follow the instructions on warning labels during maintenance.
41605601TH Rev.2 13 /
1.5.3 Warning/Caution Marking
The following warning and caution markings are made on the power supply/sensor board.
ENGLISH
Heat sink and transformer core present risk of electric shock. Test before touching.
FRENCH
Le dissipateur thermique et le noyau du transformateur présentent des risques de choc électrique.
Testez avant de manipuler.
SPANISH
Las disipadores de color el núcel del transformador pueden producir un choque eléctrico. Compruebe
antes de tocar.
PORTUGUESE
O dissipador de calor e o núcleo do fransiormador apresentam risco de choque elétrico. Teste antes
de focar.
ENGLISH
Circuits maybe live after fuses open.
FRENCH
Il se peut que les circuits soient sous tension une fois que les fusibles ont éfé rerirés.
SPANISH
Las circuitos pueden estar activos una vez que se hayan abierio los fusibles.
PORTUGUESE
Os circuitos podem estar energizados após os fusiveis se queimarem.
CAUTION
41605601TH Rev.2 14 /
2. OPERATION DESCRIPTION
OKIPAGE 14e consists of a main control board, a power supply/sensor board, an operator panel, an
electrophotographic process mechanism, and revision for illumination of LED head.
The main control board receives data via the host I/F, it then decodes, edits and stores the data in
memory. After completing the editing of a single page of data, it references the font memory and
generates bit image data, which is transferred to the LED head in one dot line units.
Through the electrophotographic process mechanism, the data is printed on the paper.
The operator panel is used for operations and status display.
OKIPAGE 14e block diagram is shown in Figure 2-1.
41605601TH Rev.2 15 /
Expansion Board
(Option)
RS232C Interface Board
or
(Option)
Main Control Board
Program & Font ROM
8MB Mask ROM
EEPROM
Centronics
parallel I/F
74LS07
USB I/F
ML60851
5V
Reset
circuit
For optional board
DATA
BUS
(32bit)
1 Chip CPU
Resident RAM
2MB x 2 DRAM
(4MB)
Registration motor
HEAT ON
Drum motor &
drive circuit
FAN Driver
Multi-Purpose
Feeder (Option)
High Capacity
Second Paper
Feeder (Option)
Operation Panel
Drum Motor
MMRegistration Motor
FAN
FAN ALM
LED Head
High Voltage
Unit
Inlet sensor 1
Inlet sensor 2
Paper sensor
Outlet sensor
Paper out sensor
Toner low sensor
5V
12V
30V
5V
AC-DC
Converter
Cover
open
switch
LSI
Sub-
Charge roller
Charge roller
High voltage
generation
circuit
Fusing temperature
control circuit
Heater drive
circuit
Filter circuit AC IN
Transfer roller
Developping
roller
Toner supply
roller
Cleaning
roller
Thermistor
Heater
Power Supply Unit
Figure 2-1 OKIPAGE 14e Block Diagram
41605601TH Rev.2 16 /
2.1 Main Control Board
The main control board consists of a single chip CPU, two program/font ROMs, four DRAMs, an
EEPROM, a host interface circuit, and a mechanism driving circuit.
(1) Single chip CPU
The single chip CPU is a custom CPU (32-bit internal bus, 32-bit external bus, 49.766-MHz clock)
which incorporates the RISC CPU and its peripheral devices, and has the following functions:
Built-in device Function
Chip select controller
Bus controller
DRAM controller
DMA controller
Parallel interface controller
Serial interface controller
Video output port
LED STB output port
Timer
Serial I/O port
I/O port
(2) Program and Font ROMs
The Program and Font ROMs store the equipment program and various types of fonts. Mask
ROM is used as Program and Font ROMs. The mounting locations of these Program and Font
ROMs vary depending on the type of the ROMs.
(3) DRAM
Control of ROM, DRAM and I/O device
Transfer of image data from DRAM to video output port
Control of Centronics parallel interface
Control of RS-232C serial interface
Control of LED head
Generation of various control timing
Monitoring of paper running and paper size
Control of operator panel, EEPROM, and options
Input and output of sensor and motor signals
The DRAM is a 4MB resident memory on the main control board that stores edited data, image
data, DLL data and macro data.
(4) EEPROM
4,096-bit Electrically Erasable PROM (EEPROM), is loaded with the following kinds of data:
• Menu data
• Various counter data (page counter, drum counter)
• Adjusting parameters (LED head drive time, print start position, paper feed length)
(5) Parallel Interface
Parallel data is received from a host system via parallel interface which conforms to the
IEEE1284 specification.
(6) USB Interface
Serial data is received from a host system via USB which conforms to the USB 1.1 specification.
41605601TH Rev.2 17 /
2.2 Power Supply/Sensor Board
The power supply/sensor board consists of an AC filter circuit, a low voltage power supply circuit, a
high voltage power supply circuit, heater drive circuit, and photosensors.
(1) Low Voltage Power Supply Circuit
This circuit generates the following voltages.
Output voltage Use
+5 V
+30 V
+12 V
(2) High Voltage Power Supply Circuit
This circuit generates the following voltages required for electrophotographic process from +5
V, according to the control sequence from the main control board. When cover open state is
detected, +5 V supply is interrupted automatically to stop the supply of all high-voltage outputs.
Output Voltage Use Remarks
CH
Sub CH
DB
SB
TR
CB
(3) Photosensor
The photosensor mounted on this power supply/sensor board monitors the status of paper being
fed through the printer during printing.
–1.3 KV
–1.5 KV to –1.8 KV
–265 V/+300 V
–500 V/ 0 V
+500 V to +4.5 KV/–1100 V
+400 V/–1350 V
Logic circuit supply voltage and LED head supply voltage
Motor and fan drive voltage
Source voltage for high-voltage supply
Voltage applied to charge roller
Voltage applied to sub-charge roller
Voltage applied to developing roller
Voltage applied to toner supply roller
Voltage applied to transfer roller
Voltage applied to cleaning roller
Variable
41605601TH Rev.2 18 /
The sensor layout diagram is shown in Figure 2-2.
Heat roller
Transfer roller
Exit roller
Outlet sensor
Paper sensor
Inlet
Toner
sensor 2
sensor
Paper feeding direction
Hopping
roller
Paper end sensor
Inlet sensor 1
Registration roller
Figure 2-2
Sensor Function Sensing state
Inlet sensor 1
Detects the leading part of the paper and gives the monitor timing
for switching from hopping operation to feeding operation.
ON: Paper exists.
OFF: No paper exists.
Monitors paper feeding situation and paper size based on the
paper arrival time and running time.
Inlet sensor 2
Detects the paper width.
ON: larger than A4
OFF: Smaller than A4
Paper sensor
Outlet sensor
Detects the leading portion of the paper.
Monitors the paper feeding situation.
Monitors the paper feeding and size according to the time of
arrival to and leaving past the sensor.
ON: Paper exists.
OFF: No paper exists.
ON: Paper exists.
OFF: No paper exists.
Paper end sensor
Detects the end of the paper.
ON: Paper exists.
OFF: No paper exists.
Toner low sensor
41605601TH Rev.2 19 /
Detects the lack of toner.
- - - - -
2.3 Electrophotographic Process
Paper cassette
Eject sensor lever
Eject roller assy
Heat roller
Charge
roller
Sub-charge roller
Developing
roller
Pressure roller
Toner cartridge
LED head
Image
drum
unit
Back-up roller
Cleaning roller
Transfer roller
Paper
sensor
plate
Inlet
sensor
plate
Registration roller
Hopping roller
2.3.1 Electrophotographic Process Mechanism
This mechanism actuates the printing of image data supplied by the main control board on the paper
by electrophotographic process.
The layout of the electrophotographic process mechanism is shown in Figure 2-3.
Figure 2-3
41605601TH Rev.2 20 /
(1) Image Drum Unit
The image drum unit consists of a sensitive drum, a charger, and a developer. The unit forms
a toner image on the sensitive drum, using a electrostatic latent image formed by the LED head.
(2) Registration Motor
The registration motor is a pulse motor of 48 steps/rotation with two-phase excitement by the
signal from the main control board. It drives the hopping and registration rollers via two one-way
clutches according to the direction of rotation.
(3) Main (Drum) Motor
The main or drum motor is a pulse motor of 48 steps/rotation with two-phase excitement by the
signal from the main control board and is the main motor of this mechanism.
(4) LED Head
Image data for each dot line from the main control board is received by the shift register and latch
register. The 2496 LED's are driven to radiate the image data on the image drum.
(5) Fuser
The fuser consists of a heater, a heat roller, a thermistor and a thermostat.
The AC voltage from the power supply/sensor board is applied to the heater controlled by the
HEATON signal from the main control board. This AC voltage heats the heater. The main control
board monitors the heat roller temperature via the thermistor, and regulates the heater roller to
keep it at a designated temperature in the menu, depending on the thickness of the paper (tray
1&2: light=175~185°C, medium light=180~190°C, medium=185~195°C, medium heavy and
heavy=195~205°C; manual feeding and power envelope feeder: light=165~180°C, medium
light=170~185°C, medium=175~190°C, medium heavy=180~195°C, heavy=190~205°C, transparency = 170~185°C) by connecting or disconnecting the AC voltage supply to the heater.
When an abnormal rise of the heater roller temperature takes place, the thermostat of the heater
voltage supply circuit becomes active and forcibly cuts the AC voltage supply.
The temperature setting of the fuser can be changed through operator panel setting.
41605601TH Rev.2 21 /
2.3.2 Electrophotographic Process
The electrophotographic processing is outlined below. The electrophotographic printing process is
shown in Figure 2-4.
1 Charging
The surface of the image drum is charged uniformly with a negative charge by applying the
negative voltage to the charge roller.
2 Exposure
Light emitted from the LED head irradiates the negatively charged surface of the image drum.
The surface potential of the irradiated portion of the image drum surface becomes lower, forming
the electrostatic latent image associated with the print image.
3 Developing and toner recovery
When the negatively charged toner is brought into contact with the image drum, it is attracted to
the electrostatic latent image by static electricity, making the image visible.
At the same time, the residual toner on the image drum is attracted to the developing roller by
static electricity.
4 Transfer
When paper is placed over the image drum surface, the positive charge which is opposite in
polarity to that of the toner, is applied to the reverse side of the paper by the transfer roller. The
toner is attracted by the positive charge and is transferred onto the paper. This results in the
transfer of the toner image formed on the image drum onto the paper.
5 Temporary cleaning
Residual toner which remains on the image drum without being transferred is evened out by the
cleaning roller and is temporarily attracted to the cleaning roller by static electricity.
6 Fusing
The toner image transferred onto the paper is fused to the paper by heat and pressure.
An electrophotographic process timing chart is shown in Figure 2-5.
41605601TH Rev.2 22 /
Paper eject roller
(Face down)
Power supply
Paper eject roller
Paper eject
(Face up)
Cleaning roller
LED head
Image data
Registration roller Hopping roller
Heater roller
Power
supply
Doctor blade
Power supply
(Bias voltage)
Toner supply roller
Toner cartridge
Paper
eject
Fusing
Back-up roller Transfer roller
Charger roller
Charging
Cleaning
Paper hopping
Paper feed
Image
production
developing
Transfer
Cleaning
FusingPaper eject
Path of paper feeding
Direction of rotation of the image drum
Power supply
Outlet sensor
Inlet sensor
Developing
Developing roller
Paper sensor
Exposure
Transfer
Paper path selector
Paper
registration
Paper
supply
Paper tray
Figure 2-4
41605601TH Rev.2 23 /
41605601TH Rev.2 24 /
PRINT-N
PRDY-N
DM-ON-N
Figure 2-5
RM-ON
INSNS
OUTSNS-N
OUT Sensor OFF
Feed stopIN Sensor OFFFeed start
2.3.3 Process Operation Descriptions
(1) Hopping and Feeding
Hopping and feeding motions are actuated by a single registration motor in the mechanism as
shown below:
Registration motor
a
Idle gear
Registration roller
Hopping roller
b
Motor gear
Registration gear
Hopping gear
The registration motor turning in direction "a" drives the hopping roller. The registration motor
turning in direction "b" drives the registration roller. The registration and hopping gears have oneway bearing, so turning any of these gears in the reverse direction will not transmit the motion
to the corresponding roller.
41605601TH Rev.2 25 /
(a) Hopping
1 For hopping, the registration motor turns in direction "a" (clockwise direction) and drives
the hopping roller to advance the paper until the inlet sensor turns on (in this case, the
registration gear also turns, but the registration roller is prevented from turning by the
one-way bearing).
2 After inlet sensor is turned on by the paper advance, the paper is further advanced to
a predetermined distance until the paper hits the registration roller (the skew of the
paper can thus be corrected).
Paper
a
Registration roller
Hopping roller
(b) Feeding
1 When hopping is completed, the registration motor turning in direction "b" (counter-
clockwise direction) drives the registration roller to advance the paper (in this case, the
hopping gear also turns, but the hopping roller is prevented from turning by the one-way
bearing).
2 The paper is further advanced in synchronization with the print data.
Image drum
Paper
b
Transfer roller
41605601TH Rev.2 26 /
Registration roller
Hopping roller
(2) Charging
Charging is actuated by the application of the DC voltage to the charge roller that is in contact
with the image drum surface.
Sub-Charge roller
Charge roller
Image drum
Power
supply
(Sub-CH)
(CH)
The charge roller is composed of two layers, a conductive layer and a surface protective layer,
both having elasticity to secure good contact with the image drum. When the DC voltage applied
by the power supply exceeds the threshold value, charging begins. The applied voltage is
proportional to the charge potential, with offset of approximately –550V.
charge potential
[V]
–
750
–
–
550 [V]
1300
applied voltage
41605601TH Rev.2 27 /
(3) Exposure
Light emitted by the LED head irradiates the image drum surface with a negative charge. The
surface potential of the irradiated portion of the image drum drops, forming an electrostatic latent
image associated with the image signal.
LED head
Charge roller
Power
supply
Paper
Image drum
LED head
Image drum
The image drum is coated with an underlayer (UL), a carrier generation layer (CGL), and
carrier transfer layer (CTL) on aluminum base. The organic photo conductor layer (OPC),
comprising CTL and CGL, is about 20 µm thick.
20
30mm
Image drum
CTL
CGL
UL
Base
µ
m
41605601TH Rev.2 28 /
The image roller surface is charged to about –750 V by the contact charge of the charge roller.
When the light from the LED head irradiates the image drum surface, the light energy generates
positive and negative carriers in the CGL. The positive carriers are moved to the CTL by an
electrical field acting on the image drum. Likewise, the negative carriers flow into the aluminum
layer (ground).
The positive carriers moved to the CTL combine with the negative charges on the image drum
surface accumulated by the contact charge of the charge roller, lowering the potential on the
image drum surface. The resultant drop in the potential of the irradiated portion of the image drum
surface forms an electrostatic latent image on it. The irradiated portion of the image drum surface
is kept to about –100 V.
–750
Image drum
surface potential
–100
(V)
0
Charged part
Light
from
LED
Part
irradiated
by
LED
Charged
part
41605601TH Rev.2 29 /
(4) Developing
Toner is attracted to the electrostatic latent image on the image drum surface, converting it into
a visible toner image. Developing takes place through the contact between the image drum and
the developing roller.
1 As the toner supply roller rotates while rubbing on the developing roller, a friction charge is
generated between the developing roller and the toner, allowing the toner to be attracted to
the developing roller (the developing roller surface is charged positive and the toner,
negative).
Doctor blade
Charge roller
Developing roller
Image drum
Toner supply roller
2 The toner attracted to the developing roller is scraped off by the doctor blade, forming a thin
coat of toner on the developing roller surface.
3 Toner is attracted to the exposed portion (low-potential part) of the image drum at the contact
of the image drum and the developing roller, making the electrostatic latent image visible.
–
300V
Developing roller
+
–+–+–+–+–+–+–+–+–+–+–+–+–+–+–+–+–+–+–+–+–+–+–
+++++++++++++++++++++++
–
750V–100V–750V–750V
Toner
Image drum
Exposed
part
Exposed
part
–
100V
An illustration of activities at the contact point of the image drum surface and
the developing roller (arrow marks denote the direction of the electrical field).
41605601TH Rev.2 30 /
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