OKI PAGE 16n Service manual

1.CONFIGURATION....................................................................................... 1-1

1.1 System Configuration................................................................................................. 1-1

1.2 Printer Configuration.................................................................................................. 1-2

1.3 Optional Configuration............................................................................................... 1-3

1.4 Specification............................................................................................................... 1-5

1.5 Safety Standards....................................................................................................... 1-7

1.5.1 Certification label.......................................................................................... 1-7

1.5.2 Warning label................................................................................................ 1-7

2.OPERATION DESCRIPTION...................................................................... 2-1

2.1 Main Control Board (BOARD-COM).......................................................................... 2-3

2.2 Power/Sensor Board.................................................................................................. 2-7

2.3 Relay/Driver Board (AOLC board)............................................................................. 2-9

2.4 Electro-photographic Process.................................................................................... 2-10

2.4.1 Electro-photographic process mechanism................................................... 2-10

2.4.2 Electro-photographic process....................................................................... 2-12

2.4.3 Process operation descriptions.................................................................... 2-15

2.4.4 Revision of LED Head Illumination............................................................... 2-24

2.5 Paper Jam Detection................................................................................................. 2-28

2.6 Cover Open................................................................................................................ 2-29

2.7 Toner Low Detection.................................................................................................. 2-30

2.8 Stacker-full Detection................................................................................................. 2-32

2.9 Page Size Detection.................................................................................................. 2-32

2.10PostScript Board (BOARD-PSBA) (Option)............................................................... 2-32

3.PARTS REPLACEMENT ........................................................................ 3-1

3.1 Precautions for Parts Replacement........................................................................... 3-1

3.2 Parts Layout............................................................................................................... 3-3

3.3 How to Change Parts................................................................................................. 3-7

3.3.1 Rear cover, side cover (L) Assy, face-up stacker Assy, and I/F cover Assy. 3-8

3.3.2 Contact Assy................................................................................................ 3-9

3.3.3 DC fan motor................................................................................................ 3-10

3.3.4 Manual feed hopper Assy............................................................................. 3-11

3.3.5 Side cover (R) (operator panel Assy)........................................................... 3-12

3.3.6 Earth plate BK (R) (BOARD-PSBA, BOARD-COM)..................................... 3-13

3.3.7 Stacker cover Assy, damper arm, and washer............................................. 3-14

3.3.8 Damper......................................................................................................... 3-15

3.3.9 Stacker full sensor Assy............................................................................... 3-16

3.3.10Cable cover (cable guides A and B)............................................................. 3-17

3.3.11Eject roller Assy............................................................................................ 3-18

3.3.12Paper supply guide D................................................................................... 3-19

3.3.13Separator F................................................................................................... 3-20

3.3.14Front feeder roller Assy................................................................................ 3-22

3.3.15Hopping motor.............................................................................................. 3-23

3.3.16Front feeder paper end sensor..................................................................... 3-24

3.3.17Main chassis unit.......................................................................................... 3-25

3.3.18Registration roller......................................................................................... 3-27

3.3.19Drum motor................................................................................................... 3-28

3.3.20Idle gear........................................................................................................ 3-30

3.3.21Fusing Assy.................................................................................................. 3-31

3.3.22Fuser pressure roller.................................................................................... 3-32

3.3.23EP lock shaft................................................................................................. 3-33

3.3.24Hopping roller Assy...................................................................................... 3-34

3.3.25Outlet sensor lever....................................................................................... 3-35

3.3.26Toner sensor lever........................................................................................ 3-36

3.2.27Paper sensor lever....................................................................................... 3-37

3.3.28Inlet sensor lever.......................................................................................... 3-38

3.3.29Insulator........................................................................................................ 3-39

3.3.30Paper end lever............................................................................................ 3-41

3.3.31Guide rail (L) Assy........................................................................................ 3-42

3.3.32Guide rail (R) Assy....................................................................................... 3-44

3.3.33Cover Frame................................................................................................. 3-46

3.3.34LED head...................................................................................................... 3-47

3.3.35Separator Assy............................................................................................. 3-48

3.3.36Transfer roller............................................................................................... 3-49

4.ADJUSTMENT .......................................................................................... 4-1

4.1 Maintenance Modes And Functions........................................................................... 4-1

4.1.1 User maintenance mode.............................................................................. 4-3

4.1.2 System maintenance mode.......................................................................... 4-5

4.1.3 Engine maintenance mode........................................................................... 4-8

4.1.4 EEPROM initialization.................................................................................. 4-12

4.2 Adjustment When Replacing A Part........................................................................... 4-13

4.2.1 Setting of LED head drive time..................................................................... 4-13

4.2.2 Resetting the fuser counter.......................................................................... 4-16

4.2.3 Destination setting........................................................................................ 4-17

5.PERIODIC MAINTENANCE........................................................................ 5-1

5.1 Periodic Replacing Part............................................................................................. 5-1

5.2 Cleaning..................................................................................................................... 5-1

5.2.1 Cleaning of LED lens array........................................................................... 5-1

6.TROUBLESHOOTING PROCEDURES .................................................. 6-1

6.1 Troubleshooting Tips................................................................................................. 6-1

6.2 Points to Check before Correcting Image Problems.................................................. 6-1

6.3 Tips for Correcting Image Problems.......................................................................... 6-1

6.4 Preparation for Troubleshooting................................................................................ 6-2

6.5 Troubleshooting Flow................................................................................................. 6-2

6.5.1 LCD status message/trouble list................................................................... 6-2

6.5.2 LCD message troubleshooting..................................................................... 6-13

6.5.3 Image troubleshooting.................................................................................. 6-32

7.WIRING DIAGRAM ................................................................................. 7-1

7.1 Interconnect Signal Diagram...................................................................................... 7-1

7.2 PCB Layout................................................................................................................ 7-2

7.3 Resistance Check...................................................................................................... 7-5

7.4 Program/Font ROM Location..................................................................................... 7-7

8.PARTS LIST................................................................................................ 8-1

APPENDIX A Centronics Parallel Interface.................................................. A-1

B High Capacity Second Paper Feeder.................................... B-1

C Multi Feeder............................................................................. C-1

D LocalTalk Serial Interface....................................................... E-1

(Available only when a PostScript board is mounted.)

1. CONFIGURATION

1.1 System Configuration

OKIPAGE16n consists of control and engine blocks as the standard configuration (See Figure

1-1.)

In addition, the following options are also available.

Printer

AC IN

230/240V

PC etc.

Centronics

Parallel interface

(Bidirection)

LOCAL TALK (Available only when  a PostScript board  is added.)

LAN etc.

Main control

OKI HSP

interface board

(Option)

Operator 

panel

Power/ Sensor

Board

DC Fan

Face down

stacker

LED head Drum motor  Registration motor Hopping motor

Paper tray

Paper size 

detection switch

Face up

stacker

Printer 

Mechanism

I/D unit

Toner Cartridge

Front Feede

Extension RAM

(Option)

PostScript 

board

(Option)

: Paper feeding : Singal flow

Figure 1-1

1 - 1

High Capacity Second Paper

Feeder

(Option)

*: Consumables

: produced by third vender

Multi Feeder

(Option)

1.2 Printer Configuration

The printer unit consists of the following hardware components:

• Electro-photographic processor

• Paper feeder

• Controller

• Operator panel

• Power/sensor board Figure 1-2 shows the printer unit configuration.

Face-up Stacker Assy

Rear Cover

Eject Roller Assy

Side Cover (L) Assy

Stacker Cover Assy

Operator Panel Assy

I/F Cover Assy

Fusing Assy

Front Feeder Unit

Contact

Assy

Base Unit

I/D Unit

Figure 1-2

1 - 2

1.3 Optional Configuration

The options below are available for use with OKIPAGE16n. They are sold separately from

the printer unit.

(1) Multi Feeder

(2) High Capacity Second Paper Feeder

1 - 3

(4) RAM module (72 pin SIMM, 1MB/2MB/4MB/8MB/16MB/32MB)

• 16MB RAM module

• 8MB RAM module

(5) PostScript board

1 - 4

1.4 Specification

(1) Type Desk top (2) External dimensions Height 10.6” (270 mm)

(excludes protruding Width 14.4” (366 mm)

Portion) Depth 16.9” (430 mm) (3) Weight 15.2 kg (33.5 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 –A4 –A5 –B5 –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

(6) Printing speed First print: 10 sec.

Continuous print: 16 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 (10)Power input 120 VAC + 5.5%, –15% (ODA)

230/240 VAC + 10%, –14% (ODA/OEL)

1 - 5

(11) Power consumption Peak: Approx. 600W

Typical Operation: Approx. 220W Idle: Approx. 100W Power save mode: Approx. 20W

(12) Temperature and humidity

In operation Power off mode During Storage Unit

Temperature 50 - 90 32 - 110 14 - 110

(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

(25) (26.8) (

35.6 35.6 (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

(

32 28

Operation rang

20 80

Humidity (%)

(13) Noise During operation: 50 dB (A) or less

At standby: 45 dB (A) or less Power save mode: 43 dB (A) or less

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

Image drum cartridge 30,000 (at continuous printing)

18,000 (3 page/job) 11,000 (1 page/job)

1 - 6

1.5 Safety Standards

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

Certification Label

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.

1 - 7

2. OPERATION DESCRIPTION

OKIPAGE16n consists of a main control board, a power supply/sensor board, a driver board, 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 OKIPAGE16n block diagram.

2 - 1

ROM SRAM

Z80181

DS8925

LS374

PostScript Board (BOAD-PSBA) (Option)

EEPROM

ROM

* LOCAL TALK interface

Parallel  Interface

OKI HSP interface (option)

Inlet sensor 1

Main  Control  Board (BOARD-COM)

ROM

SIMM

(Option)

D RAM

+8V

-8V

+5V

+30V

CPU

LSI

Relay/Drive Board (AOLC-PCB)

Heat on

DRIVER

EE PROM

LED head

Operator panel

2nd tray

Envelope tray

Home micro switch

Stacker full sensor

Paper end sensor

Hopping motor

AOLS-

(Option)

Paper size detection switch



AC-IN

Outlet sensor

Inlet sensor 2

Paper sensor

Paper out sensor

Toner sensor

Filter circuit

Power / Sensor board

Low voltage generation circuit

Heat on

LSI

Cover open MS

DRIVER

High voltage generation circuit

Driver

+5V

CH TR

DB SB

FAN

TH1

TH2

Charge roller Transfer roller Developing roller Toner supply roller Cleaning roller

Heater

* Available only when a PostScript board is add

Figure 2-1 OKIPAGE16n block diagram

2 - 2

Registration  motor

Drum motor

DC FAN

Thermistor

2.1 Main Control Board (BOARD-COM)

The control board consists of an one chip CPU, LSIs, 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, 32-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 ROM, DRAM and I/O device Bus controller DRAM controller

DMA controller Transfer of image data from DRAM to OST LSI

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 operator panel, EEPROM, and options

I/O port Inputting/outputting of sensor, signal and motor signal

Option I/O interface Control of OKI HSP interface

(2) Program/font ROM's

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

2 - 3

(3) DRAM's

2-Megabyte DRAM (4 Mbit DRAM x 4) is mounted as resident memory to be used for storing the program and providing various buffers. This DRAM is expandable up to 66 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 1-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 (MBCE31701-040FP-BND)

This LSI is used as a peripheral device of the CPU and performs smoothing compensation (OST) of print image data (300 dpi and 600 dpi). In addition, it transfers serially bit image data for each dot line to the LED head.

2 - 4

(6) Host interface

This printer has the following interfaces to the host.

• Centronics bidirectional parallel interface

• OKI HSP interface (Option)

• LocalTalk interface (Option. See 2.10 for details.) 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 nearfull 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.

(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) OKI HSP interface (Option)

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.

2 - 5

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 Fig. 2-2.

Printer

Network, etc

Control board

OKI HSP 

interface

LAN 

expansion board

Fig. 2-2

(For the electrical/physical characteristics of the OKI HSP interface, see the OKI HSP interface

technical manual.)

(7) RAM module

• Pin layout

1363772

• Basic specification

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

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

- Capacity: 1, 2, 4, 8, 16 or 32MB

- Parity: None

2 - 6

2.2 Power/Sensor Board

The power/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 Logic circuit supply voltage

+30 V Motor and fan drive voltage and source voltage for high-voltage supply

+8 V RESET Circuit

–8 V Local Talk Line 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

CH -1.30 KV Voltage applied to charging roller

DB -240 V/+300 V Voltage applied to developing roller

SB -360 V/450 V Voltage applied to toner supply roller

TR +4 KV/-1.3 kV Voltage applied to transfer roller Variable

CB +400 V Voltage applied to clearimng roller

(3) Photosensor

The photosensor mounted on this power/sensor board supervises the paper running state during printing.

2 - 7

Figure 2-3 shows the sensor layout diagram.

Paper running direction

Exit roller

Outlet sensor

Heat roller

Transfer roller

Sensor

Inlet sensor 1

Inlet sensor 2

Toner sensor

Inlet sensor 1

Inlet sensor 2

Paper sensor

Registration roller

Paper end sensor

Hopping

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.

Sensing state

ON: Paper exists. OFF: No paper exists.

ON: A4 or larger OFF: Smaller than A4

Paper sensor

Outlet sensor

Paper end sensor

Toner low sensor

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.

Detect the end of the paper.

Detects the lack of toner.

2 - 8

ON: Paper exists. OFF: No paper exists.

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

2.3 Relay/Driver Board (AOLC board)

This board relays signals between the Control board and the Power/Sensor board and includes

the registration motor and drum motor driver IC.

2 - 9

2.4 Electro-photographic Process

2.4.1 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 Feeder

Hopping Roller

Hopping Motor

Registration Motor

LED Head

Fuser

Face Up

Stacker

Drum Motor

Image Drum Unit

Figure 2-4

2 - 10

(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) Registration 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 registration roller.

(4) Drum motor

This drum motor is a pulse motor of 48 steps/rotation that is two-phase excited by the signal from the control board and is the main motor of this mechanism.

(5) 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.

(6) 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 (185 ~ 188°C) 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.

2 - 11

2.4.2 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.

2 - 12

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 

(Face down)

Power

supply

roller

Charger

Power

supply

eject

roller

Paper

Figure 2-5

2 - 13

Cleaning

path 

Paper 

selector

Paper

roller

eject

(Face up)

Fusing

Outlet sensor

Fusing pressure

Heater roller

Paper eject Fusing Cleaning Transfer

Feed stopIN Sensor OFF

OUT Sensor

OFF

Papaer Sensor OFF

PMON-N

RMON-N

INSNS

DMON-N

WRSNS

Figure 2-6

2 - 14

OUTSNS

Feed start

LEDSTB

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

First Tray

Turning the Hopping motor in the “a” direction drives the hopping roller of the first tray. Turning the Hopping motor in the “b” direction drives the Hopping roller of the front feeder. The both and hopping gears contain one-way bearing, so that turning each of these gears in reverse direction will not be transmitted to the corresponding roller.

One-way Clutch

Gear B

Hopping Roller

(Front Feeder)

Hopping Motor

Registration Roll

Hopping Roller

(First Tray)

2 - 15

One-way 

Clutch Gear A

(a) Hopping (1st tray)

1 Rotating the pulse motor in the direction a (CW direction) drives the hopping roller

of the first tray to advance the paper until the inlet sensor turns on. At the same time, the one-way clutch gear B also rotates. However, the hopping roller of the front feeder will not rotate due to the one-way bearing.

2 After turning on the inlet sensor, the paper advances further by a predetermined

length until it hits the registration roller. (The skew of the paper can thus be corrected.)

One-way Clutch Gear B

Inlet Sensor

Hopping Roller 

(Front feeder)

Registration Roll

Paper

Hopping Roller

(1st Tray)

2 - 16

(b) Hopping (front feeder)

1 Rotating the pulse motor in the direction b (CCW direction) drives the hopping roller

of the front feeder to advance the paper until the inlet sensor turns on. At the same time, the one-way clutch gear A also rotates. However, the hopping roller of the 1st tray will not rotate due to the one-way bearing.

A cam to push down the front feeder plate is attached on each of the ends of the hopping roller shaft. These cams push down the front feeder plate when the hopping operation is not performed so as to facilitate the setting of paper into the tray. A microswitch is provided under the front feeder plate to detect that the front feeder plate is at the lower position. When the front feeder plate is at the lower position, this microswitch causes the motor to stop.

Hopping Roller (Front Feeder)

Front Feeder 

Plate

Microswitch

Hopping Roller

(1st Tray)

Inlet Sensor

Paper

Registration Roller

One-way Clutch Gear A

2 After turning on the inlet sensor, the paper advances further by a predetermined

length until it hits the registration roller. (The skew of the paper can thus be corrected.)

2 - 17

OPC Drum

Paper

Registration

Roller

Hopping Roller

Paper Sensor

Transfer Roller

Pulse Motor

(2) Feeding

After the end of hopping, the pulse motor dedicated for driving the registration roller rotates to drive the registration roller. The driven registration roller advances the paper until it comes out of the registration roller.

When leading edge of the paper causes the paper sensor to turn on, the printing is started synchronously.

2 - 18

(3) Charging

Charging is effected by applying a DC minus voltage to the charge roller that is in contact with the image drum surface.

Power supply

Image drum

Charge roller

(4) Exposure

Power supply

Light emitted from the LED head irradiates the image drum surface with negative charges. The surface potential of the irradiated part of the image drum drops, thereby forming an electrostatic latent image associated with the image signal.

LED head

Charge roller

Image drum

LED head

Paper

Image drum

2 - 19

+ 199 hidden pages

OKI PAGE 16n Service manual

Specifications and Main Features

Frequently Asked Questions

User Manual

CONTENTS

1. CONFIGURATION

2. OPERATION DESCRIPTION