OKI PAGE 14ex Service manual

OKIPAGE 14ex LED Page Printer

Maintenance Manual

ODA / OEL / INT

Rev.2 2001-03-19

41356901TH Rev.2 1 / 196

Document Revision History

Rev.No. Date

No.

Corrected items

Page Description of change

Person in

1 2000-09-21 ISSUE EMP Ono 2 2001-03-19 NP39 H Ono

charge

41356901TH Rev.2 2 /

PREFACE

This Maintenance Manual describes the field maintenance methods for LED Page Printers. This manual is written for use by service persons. Please note that you should refer to the Printer Handbook

for the handling and operating methods of the equipment.

41356901TH Rev.2 3 /

1. CONFIGURATION.................................................................................................. 7

1.1 System Configuration ..................................................................................... 7

1.2 Printer Configuration....................................................................................... 9

1.3 Optional Configuration.................................................................................... 10

1.4 Specification ................................................................................................... 12

1.5 Safety Standards ............................................................................................ 14

1.5.1 Certification Label................................................................................................... 14

1.5.2 Warning Label ........................................................................................................ 14

1.5.3 Warning/Caution Marking....................................................................................... 15

2. OPERATION DESCRIPTION ................................................................................. 16

2.1 Main Control Board......................................................................................... 18

2.2 Power Supply/Sensor Board........................................................................... 19

2.3 Electrophotographic Process.......................................................................... 21

2.3.1 Electrophotographic Process Mechanism .............................................................. 21

2.3.2 Electrophotographic Process ................................................................................. 24

2.3.3 Process Operation Descriptions............................................................................. 27

2.3.4 Revision of LED Head Illumination......................................................................... 37

2.4 Paper Jam Detection ...................................................................................... 38

2.5 Cover Open .................................................................................................... 40

2.6 Toner Low Detection....................................................................................... 41

3. PARTS REPLACEMENT........................................................................................ 43

3.1 Precautions for Parts Replacement................................................................ 43

3.2 Parts Layout.................................................................................................... 45

3.3 How to Change Parts...................................................................................... 48

3.3.1 Upper Cover Assy .................................................................................................. 49

3.3.2 LED Head............................................................................................................... 50

3.3.3 Operator Panel Assy .............................................................................................. 51

3.3.4 Lower Base Unit ..................................................................................................... 52

3.3.5 Pulse Motor (Main/Drum) ....................................................................................... 53

3.3.6 Pulse Motor (Registration)...................................................................................... 54

3.3.7 Face Up Stacker Assy............................................................................................ 55

3.3.8 Eject Roller Assy .................................................................................................... 56

3.3.9 Motor Assy ............................................................................................................. 57

3.3.10 Hopping Roller Shaft Assy ..................................................................................... 58

3.3.11 Stacker Cover Assy................................................................................................ 59

3.3.12 Registration Roller .................................................................................................. 60

3.3.13 Roller Transfer Assy............................................................................................... 61

3.3.14 Fusing Unit ............................................................................................................. 62

3.3.15 Back-up Roller........................................................................................................ 63

3.3.16 Sensor Plate (Inlet)................................................................................................. 64

3.3.17 Sensor Plate (Outlet), Sensor Wire Assy ............................................................... 65

3.3.18 Manual Feed Guide Assy ....................................................................................... 66

3.3.19 Sensor Plate (Paper Supply).................................................................................. 67

3.3.20 M7E-PCB ............................................................................................................... 68

3.3.21 Power Supply/Sensor Board, High Voltage Unit and Contact Assy ....................... 69

3.3.22 Cassette Guide L Assy........................................................................................... 70

3.3.23 Cassette Guide R Assy .......................................................................................... 71

3.3.24 Spacer Bearing (L/R).............................................................................................. 72

41356901TH Rev.2 4 /

4. ADJUSTMENT........................................................................................................ 73

4.1 Maintenance Modes and Functions................................................................ 73

4.1.1 User Maintenance Mode ........................................................................................ 73

4.1.2 System Maintenance Mode.................................................................................... 73

4.1.3 Engine Maintenance Mode..................................................................................... 74

4.1.4 EEPROM initialization ............................................................................................ 75

4.2 Adjustment When Replacing a Part................................................................ 76

4.2.1 Uploading/Downloading EEPROM data................................................................. 76

5. PERIODICAL MAINTENANCE .............................................................................. 77

5.1 Periodical Replacement Parts ........................................................................ 77

5.2 Cleaning.......................................................................................................... 77

5.2.1 Cleaning of LED Lens Array ................................................................................... 77

5.2.2 Cleaning Page Function ......................................................................................... 79

6. TROUBLESHOOTING PROCEDURES ................................................................. 80

6.1 Troubleshooting Tips ...................................................................................... 80

6.2 Points to Check before Correcting Image Problems....................................... 80

6.3 Tips for Correcting Image Problems............................................................... 80

6.4 Preparation for Troubleshooting ..................................................................... 81

6.5 Troubleshooting Flow ..................................................................................... 82

6.5.1 LCD Status Message/Problem List ........................................................................ 82

6.5.2 LCD Message Troubleshooting.............................................................................. 92

7. WIRING DIAGRAM................................................................................................ 112

7.1 Interconnect Signal Diagram .......................................................................... 112

7.2 PCB Layout and Connector Signal List .......................................................... 113

7.3 Resistance Check........................................................................................... 123

8. PARTS LIST ........................................................................................................... 125

APPENDIX A RS-232C SERIAL INTERFACE (OPTION) ........................................... 132

APPENDIX B CENTRONICS PARALLEL INTERFACE.............................................. 137

APPENDIX C UNIVERSAL SERIAL BUS (USB)......................................................... 143

APPENDIX D LOOP TEST (RS-232C INTERFACE) ................................................... 147

APPENDIX E DIAGNOSTICS TEST ............................................................................ 148

APPENDIX F MULTI PURPOSE FEEDER MAINTENANCE..................................... 157

1. OUTLINE ........................................................................................................ 157

1.1 Functions................................................................................................................ 157

1.2 External View and Component Names .................................................................. 157

2. MECHANISM DESCRIPTION ........................................................................ 158

2.1 General Mechanism ............................................................................................... 158

2.2 Hopper Mechanism ................................................................................................ 158

41356901TH Rev.2 5 /

3. PARTS REPLACEMENT................................................................................ 159

3.1 Precautions Concerning Parts Replacement ......................................................... 159

3.2 Parts Layout ........................................................................................................... 161

3.3 Parts Replacement Methods .................................................................................. 162

3.3.1 Link........................................................................................................... 163

3.3.2 Separator ................................................................................................. 164

3.3.3 OLEV-11-PCB.......................................................................................... 165

3.3.4 Pulse Motor .............................................................................................. 166

3.3.5 Planet Gear .............................................................................................. 167

3.3.6 Roller-A and B.......................................................................................... 168

4. TROUBLESHOOTING.................................................................................... 169

4.1 Precautions Prior to the Troubleshooting ............................................................... 169

4.2 Preparations for the Troubleshooting ..................................................................... 169

4.3 Troubleshooting Method......................................................................................... 170

4.3.1 LCD Status Message List......................................................................... 170

5. CONNECTION DIAGRAM.............................................................................. 172

5.1 Interconnection Diagram ........................................................................................ 172

5.2 PCB Layout ............................................................................................................ 173

6. PARTS LIST ................................................................................................... 174

APPENDIX G HIGH CAPACITY SECOND PAPER FEEDER ................................... 176

1. OUTLINE ........................................................................................................ 176

1.1 Functions................................................................................................................ 176

1.2 External View and Component Names .................................................................. 176

2. MECHANISM DESCRIPTION ........................................................................ 177

2.1 General Mechanism ............................................................................................... 177

2.2 Hopper Mechanism ................................................................................................ 177

3. PARTS REPLACEMENT................................................................................ 178

3.1 Precautions Concerning Parts Replacement ......................................................... 178

3.2 Parts Layout ........................................................................................................... 180

3.3 Parts Replacement Methods .................................................................................. 181

3.3.1 Stepping Motor (Hopping) ........................................................................ 182

3.3.2 TQSB-2 PCB............................................................................................ 184

3.3.3 Hopping Roller Shaft Assy and One-way Clutch Gear............................. 184

4. TROUBLESHOOTING.................................................................................... 185

4.1 Precautions Prior to the Troubleshooting ............................................................... 185

4.2 Preparations for the Troubleshooting ..................................................................... 185

4.3 Troubleshooting Method......................................................................................... 186

4.3.1 LCD Status Message List......................................................................... 186

5. CONNECTION DIAGRAM.............................................................................. 188

5.1 Interconnection Diagram ........................................................................................ 188

5.2 PCB Layout ............................................................................................................ 189

6. PARTS LIST ................................................................................................... 190

41356901TH Rev.2 6 /

1. CONFIGURATION

1.1 System Configuration

OKIPAGE 14ex 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.

41356901TH Rev.2 7 /

Paper

Cassette

*High Capacity Second Paper

Feeder

Operator Panel

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

* : Optional

RS-232C

Expansion Board 1 DRAM SIMM Socket 1 Flash SIMM Socket

RS-232C Serial*

Interface Board 1 DRAM SIMM Socket 1 Flash SIMM Socket

DRAM SIMM*

Flash SIMM* (Flash memory)

Figure 1-1

41356901TH Rev.2 8 /

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.

Operator panel assy

Upper cover

Stacker assy

Optional board

Fusing unit

Toner-cartridge(Type 5)

(consumable)

Image drum unit(Type 8)

(consumable)

Legal/universal paper cassette

Power supply

Main control board

High Voltage Unit/sensor board

Figure 1-2

41356901TH Rev.2 9 /

1.3 Optional Configuration

The options shown below are available for use with OKIPAGE 14ex. These are available separately from the printer unit.

(1) High Capacity Second Paper Feeder

(2) Multi Purpose Feeder

(3) Expansion Board

41356901TH Rev.2 10 /

(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.

41356901TH Rev.2 11 /

1.4 Specification

(1) Type Desktop (2) External dimensions Height 8.5” (215 mm)

(3) Weight Approx. 9kg (4) Developing method Dry electrophotography

Exposing method LED stationary head

(5) Paper used <Type>

Width 13.6” (345 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)

– 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 (11ppm)]

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 600 × 600 dots/inch

600 × 1200 dots/inch

(10)Power input 120 VAC + 5.5%, -15%

230 VAC ± 10%

41356901TH Rev.2 12 /

(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

(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

(

32 28

Operation range

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) 4,000(optional 4K

Toner 5% duty)

OEL/INT : 2,500 (5%duty) 4,000(optional 4K

Toner 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) with Power Save

(Minimum)

41356901TH Rev.2 13 /

1.5 Safety Standards

1.5.1 Certification Label The safety certification label is affixed to the printer in the position described below.

INT AC : 230V model

ODA AC : 120V model ODA 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.

41356901TH Rev.2 14 /

1.5.3 Warning/Caution Marking The following warning and caution markings are made on the power supply/sensor board.

ENGLISH

FRENCH

SPANISH

CAUTION

ATTENTION ATENCÃO CUIDADO CUIDÃDO

ENGLISH Heatsink 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.

Circuits maybe live after fuses open.

Il se peut que les circuits soient sous tension une fois que les fusibles ont éfé rerirés.

Las circuitos pueden estar activos una vez que se hayan abierio los fusibles.

PORTUGUESE

Os circuitos podem estar energizados após os fusiveis se queimarem.

41356901TH Rev.2 15 /

2. OPERATION DESCRIPTION

OKIPAGE 14ex 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 14ex block diagram is shown in Figure 2-1.

41356901TH Rev.2 16 /

Expansion Board

(Option)

RS232C Interface Board

(Option)

Main Control Board

Program & Font ROM

8MB Mask ROM

EEPROM

Centronics parallel I/F

74LS07

USB I/F

ML60851

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 Voltade Unit

Inlet sensor 1

Inlet sensor 2

Paper sensor

Outlet sensor

Paper out sensor

Toner low sensor

3.3V 5V

12V 30V

AC-DC

Converter

Cover

open

switch

LSI

Charge roller

Transfer roller

High voltage

generation

circuit

Fusing temperature

control circuit

Heater drive

circuit

Filter circuit AC IN

Developping

roller

Toner supply

roller

Cleaning

roller

Thermistor

Heater

Power Supply Unit

Figure 2-1 OKIPAGE 14ex Block Diagram

41356901TH Rev.2 17 /

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:

(2) Program and Font ROMs

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

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.

41356901TH Rev.2 18 /

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 +3.3V

(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 DB SB TR CB

(3) Photosensor

-1.3 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 Motor and fan drive voltage and source voltage for high-voltage supply Source voltage for high-voltage supply LED head supply voltage

Voltage applied to charging roller Voltage applied to developing roller Voltage applied to toner supply roller Voltage applied to transfer roller Voltage applied to cleaning roller

Variable

The photosensor mounted on this power supply/sensor board monitors the status of paper being fed through the printer during printing.

41356901TH Rev.2 19 /

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.

: Paper exists.

OFF

: No paper exists. Monitors paper feeding situation and paper size based on the paper arrival time and running time.

Intel sensor 2

Paper sensor

Outlet sensor

Detects the paper width.

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.

: A4 or larger

OFF

: Smaller than A4

: Paper exists.

OFF

: No paper exists.

: Paper exists.

OFF

: No paper exists.

Paper end sensor

Toner low sensor

41356901TH Rev.2 20 /

Detects the end of the paper.

Detects the lack of toner.

: Paper exists.

OFF

: No paper exists.

- - - - -

2.3 Electrophotographic Process

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.

41356901TH Rev.2 21 /

Paper cassette Eject sensor lever

Eject roller assy Heat roller Charge roller

Developing

roller

LED head

Image drum unit

Back-up roller

Cleaning roller

Transfer roller Paper sensor

plate

Inlet

sensor

plate

Registration

roller

Hopping roller

Toner cartridge

Pressure roller

Sub-charge roller

Figure 2-3

41356901TH Rev.2 22 /

(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 4992 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.

41356901TH Rev.2 23 /

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.

41356901TH Rev.2 24 /

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

41356901TH Rev.2 25 /

41356901TH Rev.2 26 /

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

Idle gear

Registration roller

Hopping roller

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.

41356901TH Rev.2 27 /

(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 oneway 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

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

Transfer roller

Registration roller

Hopping roller

41356901TH Rev.2 28 /

(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.

Power

supply

(Sub-CH) (CH)

Sub-charge roller

Charge roller

Image drum

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

-1300-550 [V]

applied voltage

41356901TH Rev.2 29 /

(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.

30mm

Image drum

CTL CGL

Base

41356901TH Rev.2 30 /

+ 166 hidden pages

OKI PAGE 14ex Service manual

Document Revision History

CONTENTS

1. CONFIGURATION

2. OPERATION DESCRIPTION