Canon OKIPAGE 24dx Service manual

OKIP AGE24DX / OKIP AGE24dx

LED Page Printer

Maintenance Manual

ODA/ OEL/ INT

1999.5.31 Rev. 1

40930701TH Rev. 1 1 / 237

PREFACE

This maintenance manual describes the field maintenance methods for OKIPAGE24DX/OKIPAGE24dx. This manual is written for use by maintenance personnel. Note, however, that the user should refer to

the USER’S MANUAL for methods of handling and operating the equipment.

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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

2. OPERATION DESCRIPTION ...................................................................... 14

2.1 Main Control Board (BOARD-FFF) ............................................................................ 16

2.2 Power Supply Unit ..................................................................................................... 20

2.3 Electro-photographic Process.................................................................................... 22

2.3.1 Electro-photographic process mechanism ................................................... 22

2.3.2 Electro-photographic process....................................................................... 24

2.4.3 Process operation descriptions .................................................................... 28

2.3.4 Revision of LED Head Illumination ............................................................... 39

2.4 Paper Jam Detection ................................................................................................. 47

2.5 Cover Open................................................................................................................ 48

2.6 Toner Low Detection.................................................................................................. 49

2.7 Stacker-full Detection................................................................................................. 51

2.8 Page Size Detection .................................................................................................. 51

3. PARTS REPLACEMENT............................................................................. 52

3.1 Precautions for Parts Replacement ........................................................................... 52

3.2 Parts Layout............................................................................................................... 54

Figure 3-4 .................................................................................................................. 57

3.3 How to Change Parts................................................................................................. 58

3.3.1 Face -up Stacker Assy ................................................................................. 59

3.3.2 Contact Assy ................................................................................................ 60

3.3.3 DC Fan Motor ............................................................................................... 61

3.3.4 OP Panel Assy ............................................................................................. 62

3.3.5 Board-FFF .................................................................................................... 63

3.3.6 Stacker Assy, Damper Arm, Cover Rear..................................................... 64

3.3.7 Sensor Stacker Full ...................................................................................... 65

3.3.8 Cable cover (guide film)................................................................................ 66

3.3.9 Damper......................................................................................................... 67

3.3.10 Feeder Unit-Front ......................................................................................... 68

3.3.11 Roller Assy-Regist ........................................................................................ 69

3.3.12 Motor -Main .................................................................................................. 70

3.3.13 Guide Assy-Eject .......................................................................................... 72

3.3.14 Heat Assy ..................................................................................................... 73

3.3.15 Roller feed (C) ............................................................................................. 74

3.3.16 Roller Assy-BK ............................................................................................. 75

3.3.17 Roller Assy-Feed .......................................................................................... 76

3.3.18 LED Head ..................................................................................................... 77

3.3.19 Paper cassette, ROLLER Ass-Feed, ROLLER-Assy-Hoppibg..................... 78

3.3.20 Frame Assy-Separation................................................................................ 79

3.3.21 Transfer Roller/TR Gear/TR Bearing............................................................ 80

3.3.22 EP lock shaft................................................................................................. 81

3.3.23 LEVER Assy- Out Sensor............................................................................. 82

3.3.24 Toner sensor lever........................................................................................ 83

3.3.25 Paper sensor lever ....................................................................................... 84

3.3.26 Inlet sensor lever .......................................................................................... 85

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3.3.27 Power supply unit ......................................................................................... 86

3.3.28 Lever-Paper end & Lever-Paper near end ................................................... 87

3.3.29 Guide Assy-Cassette (L) .............................................................................. 89

3.3.30 Guide Assy-Cassette (R).............................................................................. 90

3.3.31 Removing/Installing Duplex Unit................................................................... 92

3.3.32 Board-LEX .................................................................................................... 94

3.3.33 Connector (IMSA-9714N-14A) ..................................................................... 95

3.3.34 Photo Sensor................................................................................................ 96

3.3.35 SOLENOID Assy .......................................................................................... 97

3.3.36 Motor ............................................................................................................ 98

4. ADJUSTMENT............................................................................................. 99

4.1 Maintenance Modes And Functions........................................................................... 99

4.1.1 User maintenance mode .............................................................................. 101

4.1.2 System maintenance mode .......................................................................... 105

4.1.3 Engine maintenance mode ........................................................................... 107

4.1.4 EEPROM initialization .................................................................................. 111

4.2 Adjustment When Replacing A Part........................................................................... 112

4.2.1 Resetting the fuser counter .......................................................................... 113

4.2.2 Destination setting ........................................................................................ 114

4.2.3 Setting of LED head drive time..................................................................... 115

5. PERIODIC MAINTENANCE ........................................................................ 118

5.1 Periodic Replacing Part ............................................................................................. 118

5.2 Cleaning..................................................................................................................... 118

5.2.1 Cleaning of LED lens array........................................................................... 118

5.2.2 Cleaning the Plastic Film .............................................................................. 119

6. TROUBLESHOOTING PROCEDURES ...................................................... 120

6.1 Troubleshooting Tips ................................................................................................. 120

6.2 Points to Check before Correcting Image Problems.................................................. 120

6.3 Tips for Correcting Image Problems .......................................................................... 120

6.4 Preparation for Troubleshooting ................................................................................ 121

6.5 Troubleshooting Flow................................................................................................. 121

6.5.1 LCD status message/trouble list................................................................... 121

6.5.2 LCD message troubleshooting ..................................................................... 133

6.5.3 Image troubleshooting .................................................................................. 154

7. WIRING DIAGRAM..................................................................................... 165

7.1 Interconnect Signal Diagram...................................................................................... 165

7.2 PCB Layout................................................................................................................ 167

7.3 Resistance Check ...................................................................................................... 170

7.4 Program/Font ROM Location ..................................................................................... 172

8. PARTS LIST ................................................................................................ 174

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APPENDIX A CENTRONICS PARALLEL INTERFACE .................................... 185

PPENDIX B RS-232C SERIAL INTERFACE ................................................... 189

PPENDIX C SECOND/ THIRD PAPER FEEDER MAINTENANCE ................. 191

1. OUTLINE ................................................................................................................... 191

1.1 Functions ...................................................................................................... 191

1.2 Appearance and Parts Name ....................................................................... 191

2. Description of operartion............................................................................................ 192

2.1 Driving Mechanism ....................................................................................... 192

2.2 Hopper Mechanism ...................................................................................... 194

3. PARTS REPLACEMENT ........................................................................................... 195

3.1 Precautions Concerning Parts Replacement................................................ 195

3.2 Parts Layout ................................................................................................. 197

3.3 Parts Replacement Methods ........................................................................ 198

3.3.1 Roller assy hopping, Roller assy feed ............................................. 199

3.3.2 Cover front assy .............................................................................. 200

3.3.3 Board-BBB ...................................................................................... 201

3.3.4 Lever paper end, Lever paper near end.......................................... 202

3.3.5 Motor ............................................................................................... 203

3.3.6 Connector (IMSA-9714N-14B), Connector (IMSA-9714N-14A) ...... 204

3.3.7 Frange pulley, pulley Idle, Mini pitch belt, Plate Earth shaft,

Gear double, Tray switch assy........................................................ 205

3.3.8 Roller feed ....................................................................................... 206

3.3.9 Bracket sub roller ............................................................................ 207

3.3.10 Frame side (L) assy ........................................................................ 208

3.3.11 Frame side (R) assy ........................................................................ 209

4. TROUBLESHOOTING............................................................................................... 210

4.1 Precautions Prior to the Troubleshooting ..................................................... 210

4.2 Preparations for the Troubleshooting ........................................................... 210

4.3 Troubleshooting Method............................................................................... 211

4.3.1 LCD Status Message List ................................................................ 211

4.3.2 Troubleshooting Flow ...................................................................... 212

5. CONNECTION DIAGRAM ......................................................................................... 213

5.1 Interconnection Diagram .............................................................................. 213

5.2 PCB Layout .................................................................................................. 214

6. PARTS LIST .............................................................................................................. 215

APPENDIX D MULTI FEEDER MAINTENANCE................................................ 218

1. OUTLINE ................................................................................................................... 218

1.1 Functions ...................................................................................................... 218

1.2 External View and Component Names......................................................... 218

2. MECHANISM DESCRIPTION ................................................................................... 219

2.1 General Mechanism ..................................................................................... 219

2.2 Hopper Mechanism ...................................................................................... 219

3. PARTS REPLACEMENT ........................................................................................... 220

3.1 Precautions Concerning Parts Replacement................................................ 220

3.2 Parts Layout ................................................................................................. 222

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3.3 Parts Replacement Methods ........................................................................ 223

3.3.1 Separator ........................................................................................ 224

3.3.2 AOLE-PCB ...................................................................................... 225

3.3.3 Square-shaped connector ............................................................... 226

3.3.4 Hopping Motor................................................................................. 227

3.3.5 Planet gear ...................................................................................... 228

3.3.6 Roller B ........................................................................................... 229

3.3.7 Roller A ........................................................................................... 230

3.3.8 Mini pitch belt & Feed roller............................................................. 231

4. TROUBLESHOOTING............................................................................................... 232

4.1 Precautions Prior to the Troubleshooting ..................................................... 232

4.2 Preparations for the Troubleshooting ........................................................... 232

4.3 Troubleshooting Method............................................................................... 232

4.3.1 LCD Status Message List ................................................................ 233

4.3.2 Troubleshooting Flow ...................................................................... 234

5. CONNECTION DIAGRAM ......................................................................................... 235

5.1 Interconnection Diagram .............................................................................. 235

5.2 PCB Layout .................................................................................................. 235

6. PARTS LIST .............................................................................................................. 236

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1. CONFIGURATION

1.1 System Configuration

OKIPAGE24DX / OKIPAGE24dx consists of control and engine blocks as the standard configu-

ration (See Figure 1-1.)

In addition, the following options are also available.

PC etc.

Centronics

Parallel interface

(Bidirection)

RS-232C

Serial I/F

Printer

Operator

panel

Main control

Power supply

unit

DC Fan

Face down

stacker

Printer

Mechanism

I/D unit

LED head Motor-Main Hopping motor

AC IN

120V 230V

Face up

stacker

Toner Cartridge

Front Feeder

LAN etc.

OKI HSP

interface board

(Option)

Extension D-RAM

SIMM

(Option)

: Paper feeding : Singal flow

4MB/ 8MB

Flash ROM SIMM

(Option)

Figure 1-1

Paper tray

Paper size

detection switch

High Capacity Second Paper

Feeder

(Option)

High Capacity

Third Paper

Feeder

(Option)

*: Consumables

: produced by third vender

Multi Feeder

(Option)

Duplex Unit

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1.2 Printer Configuration

The printer unit consists of the following hardware components:

• Electro-photographic processor

• Paper feeder

• Controller

• Operator panel

• Power supply unit

• Duplex Unit Figure 1-2 shows the printer unit configuration.

Stacker Assy

Frame-OP panel Assy

Cover-Side(I/F)

Face-up stacker Assy

Cover-Rear

Cover-Side(L) Assy

Contact Assy

Cover-Frame

Plate-Shield

Heat Assy

Manual Feed Assy

Cover-Side(R)

I/D Unit

Duplex Unit

Base Unit

Figure 1-2

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1.3 Optional Configuration

The options below are available for use with OKIPAGE24DX / OKIPAGE24dx. They are sold

separately from the printer unit.

(1) Multi Feeder

(2) Second/ Third Paper Feeder

(3) D-RAM SIMM module (72 pin SIMM, 16 MB/32 MB, EDO SIMM type)

See 7.2 (1) for where to install.

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(4) Flash ROM module (72 pin SIMM, 4MB/8MB)

See 7.2 (1) for where to install.

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1.4 Specification

(1) Type Desk top (2) External dimensions Height 13.0” (331 mm)

(excludes protruding Width 14.4” (366 mm)

Portion) Depth 18.2” (462 mm) (3) Weight 21.3 kg (47 lbs) (4) Development method Dry electrophotography

Exposure method LED stationary head (5) Paper used <Type>

• Standard paper – Xerox 4200 (20 lbs)

• Application paper (manual face-up feed) – Label – Envelope – OHP paper (Transparency)

<Size>

• Standard sizes – Letter – Legal – Executive – Envelope (without Duplex printing) –A4 – A5 (without Duplex printing) – B5 (without Duplex printing) – A6 (without Duplex printing)

• 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)

[Duplex print : 16 to 24lb]

– Manual feed: Label, OHP paper (transparency)

Envelope, 16~36 lb

(6) Printing speed First print: 6.7 sec.

Continuous print: 24 sheets/min.

[at duplex print :12 sheets/min]

Warm-up time: 90 sec. [at room temperature 77˚F

(25˚C) and rated voltage (120 VAC)] (7) Paper feed method Automatic feed or manual feed (8) Paper delivery method Face down/face up (9) Resolution 600 x 600 dots/inch (default)

600 x 1200 dots/inch

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

230 VAC + 10%

(11) Power consumption Peak: Approx. 860W

Typical Operation: Approx. 460W Idle: Approx. 95W Power save mode: Approx. 0W

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(12) Temperature and humidity

In operation Power off mode During Storage Unit

Temperature 50 - 90 32 - 110 14 - 110 °F

(10 - 32) (0 - 43) (–10 - 43) (°C) Humidity Maximum wet

bulb temperature Minimum difference

of wet and dry bulb temperatures

20 - 80 10 - 90 10 - 90 %RH

77 80.4 °F

(25) (26.8) (°C)

35.6 35.6 °F (2) (2) (°C)

Notes:

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

20 80

Humidity (%)

(13) Noise During operation: 55 dBA or less

At standby: 45 dBA or less Power save mode: 43 dBA or less

(14) Consumables Toner cartridge kit 6,000 pages(5% duty)*

Image drum cartridge 30,000 pages(at continuous Simplex printing)*

19,000 pages(3 page/job)(Simplex printing)*

* Simplex printing without Power Save.

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1.5 Safety Standards

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

ex. ODA 120V

1.5.2 Warning label The warning label is affixed to the portion which may cause an injury to human body.

Follow the instructions on warning labels during maintenance.

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2. OPERATION DESCRIPTION

OKIPAGE24DX / OKIPAGE24dx consists of a main control board, a power supply unit (120V/ 230V), a power supply unit (high voltage), an operator panel and an electro-photographic process mechanism.

The control board receives data through a host I/F, decodes and edits the data, and stores the edited data in a memory. After completing edition of one page of data, it references the font memory and generates bit data on the same memory. At the same time, it transfers the bit image data to an LED head in units of one dot line.

The electro-photographic process mechanism prints data on paper. The operator panel is used for operations and status display. Fig. 2-1 shows an OKIPAGE24DX / OKIPAGE24dx block diagram.

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FLASH ROM

Module

PS ROM

MAIN BOARD (BOARD-FFF)

DUPLEX unit

MULTI feeder

Centronics

I/F

RS232C

I/F

LAN etc. (Option)

PCL ROM

Extension

DRAM

Module

DRAM

Driver

Receiver

Driver

Receiver

OKI

HSP I/F

Board

(Option)

3V 5V +8V -8V 38V

CPU

LSI

EEPROM

TRANSISTOR

DRIVER

2nd tray

Paper end sensor

Paper near end sensor

BOARD PXC

Clutch for

Regist Roller

Clutch for

Hopping Roller

Hopping Motor

Main Motor

Operator panel

LED HEAD

3rd tray

Tray size sensor board

POWER SUPPLY UNIT (AC120V/230V)

Outlet sensor

FILTER CIRCUIT

AC120V/230V

LOW VOLTAGE

GENERATION

CIRCUIT

DRIVER

COVER

OPEN

POWER SUPPLY UNIT (high voltage)

LSI

HIGH

VOLTAGE

CIRCUIT

Inlet sensor1 paper sensor

Inlet sensor2 Toner sensor

Sub-CH

THERMISTOR

SUB CHARGE ROLLER

CHARGE ROLLER

TRANFER ROLLER

DEVELOPPING ROLLER

TONER SUPPLY ROLLER

CLEANING ROLLER

FAN

HEATOR

Figure 2-1 OKIPAGE24DX / OKIPAGE24dx block diagram

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2.1 Main Control Board (BOARD-FFF)

The control board consists of an one chip CPU,a LSI, program/font ROM's, DRAM's, an EEPROM,

a host interface circuit, and a mechanism driving circuit. (1) One-chip CPU

The one-chip CPU is a custom CPU (32-bit internal bus, 32-bit external bus, 120-MHz clock) that incorporates an RISC CPU and its peripheral devices, and has the following functions.

Built-in device Function

Chip select controller Control of peripheral LSI, ROM, DRAM and I/O device Bus controller DRAM controller

DMA controller Transfer of data from Host I/F to RAM Serial interface controller Control of RS232C serial interface Parallel interface controller Control of Centronics parallel interface Timer Generation of various control timing

Monitoring of paper running and paper size

Serial I/O port Control of serial interface between controller and operator panel, EEPROM

Control of a serial interface between controller and power supply board

I/O port Inputting of various sensor signals

Outputting of various control signals Motor driver controller Control of Main Motor Image processing circuit Executes the image data process for printing.

(2) Program/font ROM's

• PCL ROM

The program/font ROM's store the HP LJ5 emulation program and various types of font. MASK ROM is used as the program/font ROM's.

• PS ROM

The program/font ROM's store the Adobe PostScript Level 2 program and its fonts.

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(3) DRAM's

16-Megabyte DRAM (64 Mbit DRAM x 2) is mounted as resident memory to be used for storing the program and providing various buffers. This DRAM is expandable up to 128 Mbytes by adding expansion memory (SIMMs). This DRAM provides the areas shown in the following table.

Memory area Use Memory capacity setting

MENU Expansion RAM

System area Fixed Fixed Raster buffer Enable Expandable Receive buffer Enable Expandable

Page buffer – Expandable

DLL/macro buffer – Expandable Font cache buffer Enable Expandable

Working area used for the program Stores converted bit image data Stores temporarily the data received

from the host interface Adds print information to the analyzed

receive data and stores the resulted data.

Stores soft fonts and macro data. Stores bit map fonts generated by the

font rasterizer based on scalable font information

(4) EEPROM

The EEPROM has a 16-kbit capacity and stores the following data.

• Menu data

• Various counter data (page counter, drum counter, fuser counter, etc.)

• Adjustment parameters (LED head drive time, print start position, etc.)

(5) LSI (LZ9FF22)

Built in device Function Serial I/O port Control of serial interface between controller and 2nd tray, 3rd tray, Multi purpose feeder

Control of serial interface between controller and Duplex unit Motor driver controller Control of Hopping motor I/O port Inputting of various sensor signals

Outputting of various control signals

(6) Host interface

This printer has the following interfaces to the host.

• Centronics bidirectional parallel interface

• RS232C interface

• OKI HSP interface (Option) The single effective interface or the automatic interface select mode can be selected using

the menu. If the busy state of the printer continues for a long time period, the buffer near-full control releases the busy status at constant intervals even if the host side is busy so not to cause the interface time-out at the host side.

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(a) Centronics bidirectional parallel interface

This is an interface conforming to IEEE-1284 and provides either of unidirectional and bidirectional communications according to each of the following communication modes.

• Compatibility mode Unidirectional communications from the host to the printer.

• Nibble mode This mode transmits 4-bit wide data from the printer to the host. In this mode, each 1-byte data is transferred in the form of two nibbles using ERROR, BUSY, FAULT, and SELECT signal leads. This mode can provide the bidirectional operation in combination with the compatibility mode.

• ECP mode This mode provides the asynchronous bidirectional interface and transmits and receives 1-byte data using eight data signal leads under the semi-duplex control by the host.

When the power is turned on, the compatibility mode is automatically selected. The change to another mode from the compatibility mode is made through negotiation. (When the BI DIRECTION is set to ENABLE in the menu, this change can be performed.) (For the electrical/physical characteristics of this interface, see APPENDIX B)

(b) RS232C serial interface

The following protocol is supported for the serial interface conforming to EIA RS232C.

• READY/BUSY (DTR HI or DTR LO)

• X-ON/X-OFF

• RBST X-ON

(For the electrical/ physical characteristics of the interface, see APPENDIX B)

This interface (slot) is an OKI unique universal interface that provides the platform to connect various of boards (including those supplied by third venders) such as the LAN connection expansion board and SCSI expansion board. Any expansion boards compatible with this interface can be mounted on the Control board in the piggyback board from without modifying the program at the printer side. The conceptual diagram of the OKI HSP interface is shown in Figure 2-2. (For the electrical/physical characteristics of the OKI HSP interface, see the OKI HSP interface technical manual.)

Printer

Network, etc.

Control board

LAN

expansion board

OKI HSP

interface

Figure 2-2

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(7) RAM module

• Pin layout

1363772

• Basic specificaton

- Type: 72 pins Standerd SIMM (32 bits buss width)

- Access time: 60ns, 70ns, 80ns, 100ns

- Capacity: 16 or 32MB

- Parity: None

(8) Flash ROM module

• Pin layout

Board-FSL or Board-FSL-2

(4MB)

[Note : EDO SIMMtype]

(8MB)

1363772

• Basic specificaton

- Type: 72 pins SIIM (32 bits buss width)

- Access time: 90ns

- Capacity: 4 or 8MB

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2.2 Power Supply Unit

The power supply unit 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 Logic circuit supply voltage +30 V Motor and fan drive voltage and source voltage for high-voltage supply +8 V Reset circuit, RS232C Line voltage –8 V RS232C Line voltage +3.8V LED HEAD supply voltage

(2) High voltage power supply circuit

This circuit generates the following voltages necessary for electro-photographic processing from +30 V according to the control sequence from the control board. When cover open state is detected, +30 V supply is automatically interrupted to stop the supply of all the high-voltage outputs.

Output Voltage Use Remarks

Sub-CH -15 µA Voltage applied to Sub charging roller CH -1.30 KV Voltage applied to charging roller DB -220 V/+300 V Voltage applied to developing roller SB -450 V Voltage applied to toner supply roller TR +4 KV/-1.3 kV Voltage applied to transfer roller Variable + Only CB +450 V/-1350V Voltage applied to clearimng roller

(3) Photosensor

The photosensor mounted on this power supply unit supervises the paper running state during printing.

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Figure 2-3 shows the sensor layout diagram.

Paper running direction

Roller-Heat

Roller-transfer

Roller-exit

Roller-feeder (c)

Outlet sensor

Sensor

Inlet sensor 1

Inlet sensor 2

Toner sensor

Inlet sensor 1

Inlet

sensor 2

Paper sensor

Roller-regist

Feed roller

Figure 2-3

Function

Detects the leading part of the paper and gives the supervision timing for switching from hopping operation to feeding operation.

Supervises the paper running state and the paper size according to the paper reach time and running time.

Detects the form width.

ON: Paper exists. OFF: No paper exists.

ON: A4 or larger OFF: Smaller than A4

Sensing state

Paper sensor

Outlet sensor

Toner low sensor

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Detects the leading part of the paper.

Supervises the paper running state.

Supervises the paper feed and size according to the time of arrival to the sensor and the time of passage of paper.

Detects the lack of toner.

ON: Paper exists. OFF: No paper exists.

ON long: Toner low exists OFF short: No Toner low exists

2.3 Electro-photographic Process

2.3.1 Electro-photographic process mechanism This mechanism prints image data from the control board on the paper by electro-photographic

process. The Figure 2-4 shows the layout of the electro-photographic process mechanism.

Front Hopping Roller

Front Feeder

Roller Assy-Feed

Image Drum Unit

Hopping Motor

1st Hopping Roller

Sub Roller

LED HEAD

Motor-Main

Heat Assy

Face Up stacker

Duplex Unit

Figure 2-4

40930701TH Rev. 1 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) Hopping motor

This motor is a pulse motor of 48 steps/rotation that is two-phase excited by the signal from the control board. It drives the hopping roller of the first tray and the front feed roller via two one-way clutches according to the direction of rotation.

(3) Motor-Main

This motor is a pulse motor of 72 steps/rotation that is two-phase excited by the signal from the control board and is the main motor of this mechanism.

(4) Clutch (for Regist)

Swithes the transfer of power to Roller Regist if necessary depending on the power from Motor-Main and instructions from the control PCB.

(5) Clutch (for Feed Roller)

Swithes the transfer of power to Feed Roller if necessary depending on the power from MotorMain and instructions from the control PCB.

(6) LED head

Image data for each dot line from the control board is received by the shift register and latch register. The 4992 LEDs are driven to radiate the image data to the image drum.

(7) Fuser

The fuser consists of a heater, a heat roller, a thermistor and a thermostat. An AC voltage from the power supply board is applied to the heater under the control of the HEATON signal from the control board. This AC voltage heats the heater. The control board supervises the heat roller temperature via the thermistor, and regulates the heater roller at a predetermined temperature (202 °C : Normal paper, MEDIA TYPE = MEDIUM) by connecting or disconnecting the AC voltage supply to the heater. If the heater roller temperature rises abnormally, the thermostat of the heater voltage supply circuit is activated to cut the AC voltage supply forcibly.

(8) Duplex Unit

Duplex Unit is a unit, which is installed on the printer unit for controlling both-sided printing from the printer unit, intended for automatically reversing paper of which one side have been already printed and re-feeding them to the unit for printing other side.

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2.3.2 Electro-photographic process The electro-photographic processing is outlined below. Figure 2-5 shows the electro-photo-

graphic printing process.

1 Charging

The surface of the image drum is uniformly charged with negative charges by applying a 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 part of the image drum surface is lowered, so that an electrostatic latent image associated with the print image is formed.

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 and a positive charge, opposite in polarity to the toner, is applied to the reverse side of the paper from the transfer roller, the toner is attracted by the positive charge and is transferred to the paper. As a result, the toner image formed on the image drum is transferred to the paper.

5 Temporary cleaning

Residual toner that remains on the image drum without being transferred is made uniform by the cleaning roller and is temporarily attracted to the cleaning roller by static electricity.

6 Fusing

The toner image transferred to the paper is fused under heat and pressure. Figure 2-6 shows an electro-photographc process timing chart.

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Toner

cartridge

Toner

supply roller

Front

feeder

Path of paper feeding

Direction of rotation of

the image drum

Image data

LED head

Power

supply

(Bias voltage)

Exposure

Charging

blade

Doctor

Inlet sensor

roller

Developing

Paper sensor

Developing

Cleaning

Paper

supply

Paper

registration

Transfer

roller

Hopping

roller

Registration

Image

production

roller

Transfer

Power

supply

developing Paper feed Paper hopping

eject

roller

Paper

eject

Paper

Power

(Face down)

supply

roller

Charger

Power

eject

Paper

supply

roller

Cleaning

path

Paper

selector

roller

eject

Paper

Fusing

Outlet sensor

(Face up)

Fusing pressure

Heater roller

Paper eject Fusing Cleaning Transfer

Figure 2-5

40930701TH Rev. 1 25 /

40930701TH Rev. 1 26 /

DMON-N (DRUM MOTOR)

HMON-N (HOPPING MOTOR)

PWM1-P (CLUCH for hopping)

PWM2-P (CLUCH for REGISTRATION)

Figure 2-6

PSIN1-N (INLETSENSOR1)

WRSENSE-N (PAPER SENSOR)

PSOUT-N (OUTLET SENSOR)

STB-N (LED HEAD)

OFF ON

ON OFF

OFF ON

PAPER TRAYPAPER PRINTER

STACKER

SIMPLEX PRINTING TIMING CHART

40930701TH Rev. 1 27 /

DMON-N (DRUM MOTOR)

HMON-N (HOPPING MOTOR)

PWM1-P CLUCH for hopping)

PWM2-P (CLUCH for REGISTRATION)

PSIN1-N (INLETSENSOR1)

WRSENSE-N (PAPER SENSOR)

PSOUT-N (OUTLET SENSOR)

Figure 2-7

STB-N (LED HEAD)

DUPMON-N (MAIN MOTOR in DUPLEX UNIT)

CLON-P (CLUCH in DUPLEX UNIT)

SLON-P (SOLENOID in DUPLEX UNIT)

DUPINSNS-N (INLET SENSOR in DUPLEX UNIT)

DUPRSNS-N (REAR SENSOR inDUPLEX UNIT)

DUPFSNS-N (FRONT SENSOR in DUPLEX UNIT)

OFF ON

ON OFF

OFF ON

ON OFF

OFF ON

PAPER PRINTER PRINTER STACKERDUPLEX UNIT

PAPER

TRAY

PRINTER/

DUPLEX UNIT

DUPLEX UNIT/

PRINTER

DUPLEX PRINTING TIMING CHART

2.4.3 Process operation descriptions

(1) Hopping

Hoppings from the first tray and the front feeder are effected by a single hopping motor in the mechanism shown below.

Hopping Motor

Front Feeder

Duplex Unit

1st Tray

Turning the Hopping motor in direction a (CW) drives the 1st Hopping Roller. Turning the Hopping motor in direction b (CCW) drives the Front Hopping Roller. Gear C and Hopping roller bult in one-way bearing, so that turning each of these gears in reverse direction will not be transmitted to the corresponding roller.

Gear C

(One-way Clutch build-in )

Front Hopping Roller

(One-way clutch build-in)

(CW)

(CCW)

Inlet Sensor

Hopping Motor

Roller-Regist

Planet Gear

Gear B

1st Hopping Roller

(One-way clutch build-in)

Sub Roller

Gear A

Paper

40930701TH Rev. 1 28 /

(a) Hopping from the 1st Tray

1 Hopping

Rotating the Hopping Motor in direction a (CW) drives the 1st Hopping Roller and the Sub Roller then pick up a sheet of paper in the 1st tray. The Main Motor is always driven in direction c (CCW) on printing. After the paper fed approx. 30mm from the tray, the Clutch (Feed) drives the Align Roller to advance the paper until the Inlet Sensor turns on.

2 Aligning

After turning on the Inlet Sensor, the paper fed by a predetermined length and choked up to the wedge space formed by the Regist Roller and the Pressure Roller so that to align the skew of paper.

3 During the paper fed from the 1st tray, the build in clutch of Gear C is idled and not

to drive the Front Hopping Roller.

4 Feeding

After aligned the paper, the Hopping Motor turned off and stop hopping. Also the Clutch (Feed) turned off and the Align Roller idled freely. Then Clutch (Regist) turned on and the Regist Roller start to feed the paper. After the paper fed, the 1st Hopping Roller is freely idled by releasing build in one way clutch, also the Sub Roller is freely idled by escaping the Planet Gear.

5 Start printing. after the paper turns off the Write Sensor.

Align Roller

Clutch (Feed)

Gear D

Pressure Roller

Inlet Sensor

Gear E

Regist Roller

Write Sensor

Clutch (Regist)

Main Motor

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(b) Hopping from the Front Feeder

1 Hopping

The Front Feeder Plate is normally locked at the lower position by the Release Lever and turn the Micro SW on. Top of the FF Cam which attached on end of the Front Hopping Shaft is normally located Upper position (0 to 30 degree : home position). Rotating the Hopping Motor in direction b (CCW) drives the Front Hopping Shaft and then attached the FF Cam and the Front Hopping Roller are driven. During the FF Cam rotated approx. 60 degree, the Release Lever was pushed and the Front Feeder Plate lifts up, then the Front Hopping Roller picks up a sheet of paper. At the FF Cam rotated approx. 180 degree, the Front Feeder Plate is pushed down and locked by the Release Lever again. At the FF Cam rotated approx. 275 degree the paper fed until the Inlet Sensor turns off.

2 Aligning

After turning on the Inlet Sensor, the paper fed by a predetermined length and choked up to the wedge space formed by the Regist Roller and the Pressure Roller so that to align the skew of paper.

3 During the paper fed from the Front Feeder Plate, the one way clutch of 1st Hopping

Roller is idled and not to drive the 1st Hopping Roller and the Sub Roller.

4 Feeding

After aligned the paper, the Hopping Motor turned off and stop hopping. Then Clutch (Regist) turned on and the Regist Roller start to feed the paper. After the paper fed, the Front Hopping Roller drives the Front Hopping Shaft and attached the FF Cam with small idle torque of build in one way clutch and when comes into the Release Lever, the one way clutch is slipped and the FF Cam is stopped at the upper position (home position). The Front Hopping Roller continuously idled up to the paper away.

5 Start printing. after the paper turns off the Write Sensor.

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