Canon Laser Shot LBP-1120 User manual

REVISION 0
FY8-13HT-000
COPYRIGHT © 2002 CANON INC. CANON LBP-1120 REV.0 MAY. 2002 PRINTED IN JAPAN (IMPRIME AU JAPON)
JULY. 2002
SERVICE
MANUAL
LBP-1120

Application
This manual has been issued by Canon Inc. for qualified persons to learn technical theory, installation, mainte-
nance, and repair of products. This manual covers all localities where the products are sold. For this reason, there
may be information in this manual that does not apply to your locality.
Corrections
This manual may contain technical inaccuracies or typographical errors due to improvements or changes in prod-
ucts. When changes occur in applicable products or in the contents of this manual, Canon will release technical
information as the need arises. In the event of major changes in the contents of this manual over a long or short
period, Canon will issue a new edition of this manual.
The following paragraph does not apply to any countries where such provisions are inconsistent with local law.
Trademarks
The product names and company names used in this manual are the registered trademarks of the individual compa-
nies.
Copyright
This manual is copyrighted with all rights reserved. Under the copyright laws, this manual may not be copied,
reproduced or translated into another language, in whole or in part, without the written consent of Canon Inc.
Caution
Use of this manual should be strictly supervised to avoid disclosure of confidential information.
COPYRIGHT © 2002 CANON INC.
Printed in Japan
Imprimé au Japon

P - 1
PREFACE
PREFACE
This Service Manual contains basic information required for after-sales service of the laser beam printer LBP-1120
(hereinafter referred to as the “printer”). This information is vital to the service technician in maintaining the high print
quality and performance of the printer.
This manual consists of the following chapters:
Chapter 1: Product information
Features, specifications, operation, and installation
Chapter 2: Operation and Timing
A description of the operating principles and timing sequences of the electrical and mechanical systems.
Chapter 3: The Mechanical System
Explanation of mechanical operation, disassembly, reassembly and adjustment procedures
Chapter 4: Troubleshooting
Troubleshooting procedures, reference values and adjustments, maintenance and servicing, etc.
Appendix: General timing chart, general circuit diagram, etc.
Information in this manual is subject to change as the product is improved or redesigned. All relevant information in
such cases will be supplied in the Service Information Bulletins.
A thorough understanding of this printer, based on information in this Manual and Service Information bulletins, is
required for maintaining its performance and for locating and repairing the causes of malfunctions.

PREFACE
P - 2

P - 3
PREFACE
CONTENTS
CHAPTER 1 PRODUCT INFORMATION
B. Cross Section ............................. 1-6
V. INSTALLATION ................................ 1-7
A. Precautions ................................ 1-7
B. Storage and Handling of EP-22
Cartridge .................................... 1-8
VI. MAINTENANCE AND CHECKS
BY THE CUSTOMER ...................... 1-10
VII. OPERATION .................................... 1-11
A. Canon Advanced Printing
Technology (CAPT) .................... 1-11
I. FEATURES ...................................... 1-1
II. SPECIFICATIONS ........................... 1-2
A. Printer ........................................ 1-2
III. SAFETY INFORMATION ........... 1-4
A. Handling the Laser/Scanner
Unit ............................................. 1-4
B. Toner Caution ............................. 1-4
C. Ozone Safety ............................. 1-4
IV. PARTS OF THE PRINTER .............. 1-5
A. External View ............................. 1-5
CHAPTER 2 OPERATION AND TIMING
I. BASIC OPERATION ........................ 2-1
A. Functions .................................... 2-1
B. Basic Operation Sequence ......... 2-2
C. Power-ON Sequence ................. 2-3
II. ENGINE CONTROL SYSTEM ......... 2-4
A. Engine Controller PCB ............... 2-4
B. Fixing Control Circuit .................. 2-8
C. High-Voltage Power Supply
Circuit ......................................... 2-10
D. Low-Voltage Power Supply
Circuit ......................................... 2-12
E. Video Interface ........................... 2-14
III. LASER/SCANNER SYSTEM ........... 2-17
A. Outline ........................................ 2-17
B. Laser Control Circuit ................... 2-18
C. Scanner System ......................... 2-21
IV. IMAGE FORMATION SYSTEM ....... 2-23
A. Outline ........................................ 2-23
B. Print Process .............................. 2-24
V. PICK-UP/FEED SYSTEM ................ 2-31
A. Outline ........................................ 2-31
B. Jam Detection ............................ 2-33
VI. VIDEO CONTROL SYSTEM ........... 2-34
A. Interface Controller PCB ............ 2-34
CHAPTER 3 THE MECHANICAL SYSTEM
I. PREFACE ........................................ 3-1
II. EXTERNALS ................................... 3-2
A. Arrangement of the Components 3-2
B. External Covers .......................... 3-2
III. MAIN UNITS .................................... 3-5
A. Laser/Scanner Unit ..................... 3-5
B. Drive Assembly .......................... 3-5
C. Feed Assembly ........................... 3-6
D. Delivery Assembly ...................... 3-7
E. Fixing Film Unit ........................... 3-7
IV. MAJOR COMPONENTS ................. 3-9
A. Arrangement of the Components 3-9
B. Pickup Roller .............................. 3-10
C. Separation Pad ........................... 3-10
D. Transfer Charging Roller ............ 3-12
E. Pressure Roller .......................... 3-12
V. SWITCHES,SENSORS, AND LEDS 3-13
A. Arrangement of the Components 3-13
B. Paper Top Sensor/
Paper-out Sensor ....................... 3-14
C. Power Switch/Test Print Switch/
Door Open Detection Switch/
Paper Delivery Sensor ............... 3-14
D. Indicator LED ............................. 3-14

PREFACE
P - 4
VI. MOTOR/SOLENOID ........................ 3-15
A. Arrangement of the Components 3-15
B. Main Motor ................................. 3-16
C. Pick-up Solenoid ........................ 3-16
VII. PCBS ............................................... 3-17
A. Arrangement of the Components 3-17
B. Interface Controller PCB ............ 3-18
C. Engine Controller PCB ............... 3-18
D. Display PCB ............................... 3-20
CHAPTER 4 TROUBLESHOOTING
I. PREFACE ........................................ 4-1
A. Malfunction Diagnosis
Flowchart.................................... 4-1
B. Initial Check ................................ 4-4
C. Test Print .................................... 4-5
II. IMAGE DEFECTS
TROUBLESHOOTING..................... 4-7
III. JAMS TROUBLESHOOTING .......... 4-13
IV. TRANSPORT
TROUBLESHOOTING..................... 4-16
V. MALFUNCTION
TROUBLESHOOTING..................... 4-17
VI. MALFUNCTION STATUS
TROUBLESHOOTING..................... 4-18
VII. MEASUREMENT AND
ADJUSTMENT................................. 4-21
A. Mechanical Adjustment .............. 4-21
B. Electrical Adjustment .................. 4-21
C. LEDs, Test Pins, Jumpers,
and Switches on PCBs ............... 4-22
VIII. MAINTENANCE AND
SERVICING ..................................... 4-23
A. Periodic Replacement
Parts ........................................... 4-23
B. Expected Servicing Lives of
Consumable Parts ...................... 4-23
C. Periodic Service ......................... 4-23
D. Cleaning During a Service
Visit ............................................ 4-24
E. Standard Tools ........................... 4-26
F. Special Tools .............................. 4-27
G. List of Lubricants and
Cleaners ..................................... 4-27
IX. LOCATION OF CONNECTORS ...... 4-28
APPENDIX
I. GENERAL TIMING CHART ............. A-1
A. Timing Chart for Printing
Two A4-size Sheet
Continuously .............................. A-1
II. GENERAL CIRCUIT DIAGRAM ....... A-3
A. Engine Controller PCB ............... A-3
B. Interface Controller PCB ............ A-3
III. LIST OF SIGNALS ........................... A-5
A. Engine Controller ........................ A-5
IV. MESSAGES TABLE ........................ A-7
A. Message List .............................. A-7

I. FEATURES ........................................... 1-1
II. SPECIFICATIONS ................................ 1-2
III. SAFETY INFORMATION ................ 1-4
IV. PARTS OF THE PRINTER ................... 1-5
CHAPTER 1
PRODUCT INFORMATION
V. INSTALLATION ..................................... 1-7
VI. MAINTENANCE AND CHECKS
BY THE CUSTOMER ........................... 1-10
VII. OPERATION ......................................... 1-11

1 - 1
CHAPTER 1
I. FEATURES
1. Small-Sized Printer with High Speed and High Resolution
This printer has paper pick-up trays on its top for space saving, and is compact enough to set on a desk. In addition, it
has realized high speed of 10 pages per minute (A4) and high resolution of 600 dpi.
2. Employment of Canon Advanced Printing Technology
With Canon Advanced Printing Technology, data can be processed within a host computer. This frees the printer from
the PDL conversion and image processing, increasing the speed performance and reducing the cost.
3. Shortened Wait Time & Low Power Consumption
By adopting an on-demand fixing method that drives the heater only during printing, the printer has shorten the wait
time and reduced the consumption power during standby.
4. Low Noise
In addition to an on-demand fixing method, the printer has increased its heat exhaust efficiency so as to remove the fan
for realizing a low noise level.
5. Employment of USB Interface as a Standard
The printer employs an USB interface as a standard, allowing easy connection to peripherals.

CHAPTER 1
1 - 2
II. SPECIFICATIONS
A. Printer
1. Printer Engine
1) Type Desktop page printer
2) Printing method Electrophotography
3) Printing speed (Note1) 10 pages/minute (A4)
4) First print time (Note2)
Face-down 18 seconds or less
Face-up 17 seconds or less
5) Wait time (Note3) 8 seconds or less
6) Resolution
Horizontal 600 dots/inch
Vertical 600 raster lines/inch
7) Image formation system
Laser Semiconductor laser
Scanning system Rotating four-faced prism mirror
Photosensitive drum OPC
Charging Roller charging
Exposure Laser scanning
Toner Magnetic single-component dry toner
Development Toner projection development system
Toner supply Replaceable EP-22 toner cartridge (able to print approx. 2,500 A4-sized print sheets:
with image density set in the middle, and 4 % dot density ratio)
Image transfer Roller transfer
Separation Curvature separation
Cleaning Blade
Fixing method On-demand fixing
8) Feeding Manual feed slot
Multi-purpose tray
Paper types Plain paper, recycled paper, colored paper, labels, OHT, index cads, postcards and
envelops
Paper size (Note4)
Manual feed slot 76.2 mm(W) x 127 mm(L) ~ 216 mm(W) x 356 mm(L) sized paper (64 g/m2to 105
g/m2Canon recommended paper) and above mentioned paper
Multi-purpose tray 76.2 mm(W) x 127 mm(L) ~ 216 mm(W) x 356 mm(L) sized paper (64 g/m2to 105
g/m2Canon recommended paper) and above mentioned paper
Capacity
Manual feed slot one sheet
Multi-purpose Depth 12.5 mm (Approx. 125 sheets of 64 g/m2paper)
9) Delivery (Note5) Face-down/face-up
Face-down tray capacity Approx. 50 sheets of 64 g/m2paper
10) Duplex printing
Manual duplex printing The paper is picked up from the multi-purpose tray and delivered
(Note6) face-up. Only plain paper (64-105 g/m2Canon recommended paper) can be printed
duplex.
11) Operating environment
Temperature 10 to 32.5 °C (50 to 90.5 °F)
Humidity 20 to 80% RH
Air pressure 613 to 1013 hPa (460 to 760 mmHg)

1 - 3
CHAPTER 1
12) Power consumption 110-127Vmodel 220-240Vmodel
Maximum Approx. 740 W (reference) Approx. 672 W (reference)
During printing Approx. 250W (average) Approx. 250W (average)
Durimg standby Approx. 5W (average) Approx. 5W (average)
13) Noise level (Officially announced noise emission level in accordance with ISO 9296)
Sound power level 6.2 B or less (printing)
(1B = 10 dB) Dark sound level (standby)
Sound pressure level 50 dB or less (printing)
(Bystander position) Dark sound level (standby)
14) Dimensions (Note7) 362 mm(W) x 307 mm(D) x 240 mm(H)
14.2 in.(W) x 12.2 in.(D) x 9.5 in.(H)
15) Weight
printer only Approx. 6.0 Kg / 13.2 lb
cartridge Approx. 730 g / 1-5/81 lb
16) Power supply 110-127V ±10% (50/60 Hz ±2 Hz)
220-240V +6%-10% (50 Hz ±2 Hz)
Notes: 1. A test print when the room temperature is 20 °C and the rated power voltage is input.
2. The time taken from that the Print signal is received from the video controller until that an A-4
sized paper is delivered completely, and also when the printer is in the Ready mode at room
temperatures of 20 °C.
3. The time taken from that the power plug is plugged in until that the printer becomes ready to print
(Ready or Standby mode.)
4. Paper with the width of less than 182 mm should not exceed 235 mm in length.
5. Only plain paper and recycled paper can be delivered face-down.
6. To print duplex manually, uncurl the face-up delivered paper and set it in the multi-purpose tray.
7. Without the delivery guide and the paper pickup sub tray.
2. Interface controller
1) Printing System Canon Advanced Printing Technology
2) ROM capacity 8 KB
3) RAM capacity 512 KB
4) Interface USB(V1.1) interface
Specifications are subject to change with product improvement.

CHAPTER 1
1 - 4
Figure 1-3-1
B. Toner Caution
The toner is non-toxic substance composed of plastics and minute color pigments.
If toner adheres to the skin or clothing, remove as much as possible with dry tissue first, then wash with cold water,
Hot water should not be used, as the toner will solidify and become difficult to remove.
Toner will easily decompose vinyl materials, therefore avoid the toner to come close to vinyl.
C. Ozone Safety
An infinitesimal amount of ozone gas (O3) is generated during corona discharge from the charging roller. The ozone
gas is emitted only while the printer is operating.
This printer meets the ozone emission reference value set by Underwriters Laboratory (UL) at the time it is shipped
from the factory.
III. SAFETY INFORMATION
A. Handling the Laser/Scanner Unit
An invisible laser beam is emitted within the laser/scanner unit.
The laser beam can cause eye damage if exposed, so be sure not to disassemble the laser/scanner unit. It is not
necessary to adjust the laser/scanner unit in this printer in the filed.
The following label is attached to the laser/scanner cover.
UNSICHTBARE LASERSTRAHLUNG. WENN ABDECKUNG GEOFFNET.
NICHT DEM STRAHL AUSSETZEN.
RAYONNEMENT LASER INVISIBLE EN CAS D'O UVERTURE.
EXPOSITION DANGEREUSE AU FAISCEAU.
INVISIBLE LASER RADIATION WHEN OPEN.
AVOID EXPOSURE TO BEAM.
Invisible laser radiation when open.
AVOID DIRECT EXPOSURE TO BEAM.
RADIAZIONE LASER INVISIOILE IN CASO DI APERTURA.
EVITARE L'ESPOSIZIONE AL FASCIO.
RADIACION LASER INVISIBLE CUANDO SE ABRE.
EVITAR EXPONERSE AL RAYO.
AVATTAESSA OLET ALTTIINA NAKYMATTOMALLE
LASERSATEILYLLE. ALA KATSO SATEESEEN.
OSYNLIG LASERSTRALNING NAR DENNA DEL AR OPPNAD.
BETRAKTA EJ STRALEN.
USYNLIG LASER STRALING. NAR DENNE ER ABEN.
UNDGA BESTRALING.
USYNLIG LASERSTRALING NAR DEKSEL APNES.
UNNGA EKSPONERING FOR STRALEN.
DANGER
CAUTION

1 - 5
CHAPTER 1
IV. PARTS OF THE PRINTER
A. External View
[1] : Multi-purpose tray [2] : Paper width guide
[3] : Manual feed slot [4] : Delivery switching lever
[5] : Face-up delivery port [6] : Cartridge cover unit
[7] : Face-down delivery tray [8] : Display unit
[9] : Delivery guide [10] : Paper pickup sub tray
[11] : USB port [12] : Power receptacle
[13] : Power switch
Figure 1-4-1
[2]
[3]
[4]
[12][13]
[11]
[5]
[6]
[7]
[9]
[10]
[1]
[8]

CHAPTER 1
1 - 6
B. Cross Section
[1] : Face-down delivery roller [2] : Fixing film unit
[3] : EP-22 cartridge [4] : Primary charging roller
[5] : Laser/scanner unit [6] : Pick-up roller
[7] : Separation pad [8] : Feed roller
[9] : Developing cylinder [10] : Transfer charging roller
[11] : Photosensitive drum [12] : Pressure roller
[13] : Fixing delivery roller
Figure 1-4-2
[8][9][10][11][12][13]
[1] [2] [3] [4] [5] [6] [7]

1 - 7
CHAPTER 1
V. INSTALLATION
A. Precautions
This product has been carefully adjusted and strictly inspected before packing and shipping. To make the operation as
intended, it is important to install it correctly. Service engineers must understand the performance of the printer sufficiently,
install it in the appropriate environment with proper procedures, and operate the necessary checks.
The following requirements must be met when installing the printer.
The service engineer should inspect the installing site before taking the printer to the customer’s premises.
• Power must be directly connectable to a single socket with a supply voltage within ± 10 % of the rated voltage
(110-127V) or +6 % to -10 % of the rated voltage (220-240V.)
• The temperatures should be in a range from 10 to 32.5 °C and the relative humidity from 20 to 80 %. Avoid areas
closed to water faucets, boilers, humidifiers, or refrigerators.
• Avoid areas near open flames, dusty locations, windy locations, areas which emit ammonia gas, and areas directly
exposed to sunlight. When exposure to direct sunlight is unavoidable, hanging curtains is recommended.
• The room should be well ventilated.
• The printer should be placed on a level surface.
• If the printer is set up on a desk, be sure a study desk is used.
• Set the printer at a suitable distance from the wall for easy operation (See Figure 1-5-1.)
There must be enough space around the printer to operate.
Following dimensions should be taken into consideration to select an installation space for the printer.
Figure 1-5-1
When metals are moved from a cold area to warm area, condensation may appear. This can lead to various troubles
during an operation. When the printer needs to be moved from a cold area to warm area, leave it packed in its box for
at least an hour to acclimatize to room temperature.
763 mm / 30.0 in.
362 mm / 14.2 in.
442 mm / 17.3 in.
372 mm / 14.6 in.
240 mm / 9.5in.
60 mm / 2.4 in. 100 mm / 3.94 in.
307 mm / 12.2 in.
362 mm / 14.2 in. 482 mm / 18.9 in.
372 mm / 14.6 in.
240 mm / 9.5 in.
640 mm / 25.2 in.
297 mm / 11.8 in.
356 mm / 14.2 in.
Front Legal-size paper
(for Face-up delivery)
A4-size paper
(for Face-up delivery)
Dimensions Space required for installation
Top view
Side view
763 mm / 30.0 in.
100 mm / 3.94 in.
60 mm / 2.4 in.

CHAPTER 1
1 - 8
B. Storage and Handling of EP-22 Cartridge
As time passes, the natural environment will change the cartridge, whether sealed or installed in the printer, or regardless
of the number of prints. The progression of this natural change depends largely on the storage and installation environment,
therefore, take special care on storage and handling the cartridge.
a. Storage of Sealed EP-22 Cartridge Package
When storing EP-22 cartridge in warehouses or workshops, be sure that they are kept within humidity/storage conditions
range shown in Table 1-5-1.
Also note the following:
1) Avoid areas exposed to direct sunlight.
2) Do not place them in locations which are subject to severe vibration.
3) Do not bump or drop the cartridge.
4) Avoid high temperature environment, keep EP-22 cartridge below 35 °C.
Table 1-5-1
Note: Total storage time is the valid time span following the manufacture date displayed on the cartridge
box.
b. Storage of Unsealed EP-22 Cartridge
Since an organic photoconductor (OPC) is used for the photosensitive drum, intensive light will damage the drum.
Since toner is contained in the cartridge, it is necessary to thoroughly explain the various storage and handling procedures
of unsealed cartridges to customers.
Also, note the following:
1) Avoid areas which are exposed to direct sunlight such as near windows. Avoid leaving the packages in cars for an
extended period of time as high temperatures can damage them.
2) Avoid high temperature and high humidity, and low temperature and low humidity environment. Avoid areas
where the temperature or humidity drastically change such as a location near air conditioners.
3) Avoid dusty areas or locations which emit ammonia or organic solvent gases.
4) Keep EP-22 cartridge below 35 °C
5) Avoid placing the package near CRT displays, disk drive units, or floppy disks.
Normal (total storage time X 9/10)
Temperature
Severe (total storage
time X 1/10)
Air pressure
Temperature change
(within 3 minutes or so)
0 to 35˚C
35 to 40˚C
400˚C 15˚C
-20˚C 250˚C
35 t o 85 % RH
85 t o 95 % RH
10 t o 35 % RH
613 to 1013hPa
(460 to 760 mmHg)
High
Low -20 to 00˚C
Normal (total storage time X 9/10)
Severe (total storage time
X 1/10)
High
Low
Relative humidity

1 - 9
CHAPTER 1
c. Notes on Handling of Cartridge
1) Before installing a new EP-22 cartridge in the printer, hold the cartridge at both sides as shown below, and gently
slop it at about 45 ° right-up and left-up 5 or 6 times to distribute toner evenly. Do not rock the cartridge in any
other way, as the toner may leak from the developing unit or cleaner unit.
Figure 1-5-2
Print the test pattern of 3 to 5 sheets to ensure that output images are not spoiled by a toner leak after installing the
cartridge in the printer.
2) If blank spots appear on the output image due to an uneven distribution of toner in the cartridge, shake the cartridge
to evenly distribute as shown in 1).
3) Do not place the cartridge on its end or upside down.
4) Do not open the protective shutter of the photosensitive drum and never touch the drum surface. Do not clean the
photosensitive drum.
5) Do not disassemble EP-22 cartridge.
6) Do not give vibration or shock to the cartridge.
7) Intensive light easily damages the photosensitive drum, causing blank spots or black stripes on the printed image.
Faulty print images can be corrected by stopping the printer momentarily. However, if the drum is exposed too
long, the blank spots and black stripes may remain even after stopping the printer. To prevent this, be sure to
always place the unsealed cartridges in their boxes or under a cover. Do not leave them uncovered after removing
from the printer.
Reference: If the cartridge are exposed to ordinary light for five minutes and then left in a dark area for
another five minutes, the print quality will return to a virtually permissible level. However, do not
expose the cartridge to direct sunlight.

CHAPTER 1
1 - 10
VI. MAINTENANCE AND CHECKS BY THE CUSTOMER
The table below lists the maintenance points that should be performed by the customer to maintain the printer at
optimum level.
Table 1-6-1
Item
Cartridge Shake or replace the cartridge as necessary.
Customer maintenance
Clean the external cover as necessary.
External Cover

1 - 11
CHAPTER 1
VII. OPERATION
A. Canon Advanced Printing Technology (CAPT)
Canon Advanced Printing Technology (hereafter referred to as CAPT) reduces the processing time and simplifies the
operations for printing in the Microsoft Windows environment.
The easy operations and speedy printing are supported by the following features of CAPT:
• Instead of converting print data sent from application into the printer’s page description language (PDL), CAPT
translates the print data into resource data compatible to the graphic drawing system commands (GDI data.)
• The resource data compatible to the GDI data is developed to dot data, and then passed to a host computer.
• The printing environment can be set in the dialog box on the host computer screen.
• The printer status is shown on the host computer screen, so users can view and confirm the print time, print paper
status, error conditions, and etc..
Figure 1-7-1
Note: GDI : Graphic Device Interface
A graphic drawing system that performs printing and displaying in the Windows environment, (and a
graphic drawing system interface with the application.)
CAPT operates on Microsoft Windows 98/Me/2000/XP. The installation is done using the Canon Advanced Printing
Technology disk included with this printer.
CAPT specifies paper sizes, document sizes, number of copies, and print quality on the computer screen. The
operation methods of the dialog boxes vary in Microsoft Windows 98/Me/2000/XP.
Refer to the users guides for the installation procedures and operations.
Submits GDI data from
the application.
Converts into resource data
corresponding to GDI.
Formats bit images.
Analyzes the resource data and
develops them into print data
Host computer interface
Printer status information
Monitors the printer status.
Displays the printer status
on the screen.
Engine unit Printing
Host computer
Printer
Canon Advanced
Printing Technology
Printer interface

CHAPTER 2
OPERATION AND TIMING
This chapter describes the printer functions, the relationships between mechanisms and circuits, and the timing
of operations. Mechanical linkages are indicated by black and white lines ( ), the flow of control
signals by solid arrows ( ), and the flow of groups of signals by outline arrows ( ).
There is a microcomputer in this printer. But as the internal operation of the microcomputer cannot be
checked, an explanation of the operation of the microcomputer has been left out.
As it is assumed that no repair will be made to customer circuit boards, the explanation of board circuits is
limited to an outline using block diagrams. So there are two types of circuit explanations; (1) everything from
the sensor to the input sections of the major circuit boards, (2) everything from the output sections of the major
circuit boards to the loads. These are explained with block diagrams according to the function.
I. BASIC OPERATION ............................. 2-1
II. ENGINE CONTROL SYSTEM .............. 2-4
III. LASER/SCANNER SYSTEM ................ 2-17
IV. IMAGE FORMATION SYSTEM ............ 2-23
V. PICK-UP/FEED SYSTEM ..................... 2-31
VI. VIDEO CONTROL SYSTEM ................ 2-34

2 - 1
CHAPTER 2
I. BASIC OPERATION
A. Functions
Printer functions can be divided into five groups: video control system, engine control system, image formation system,
laser/scanner system, and paper pickup/feed system.
Figure 2-1-1
To external device (host computer,etc.)
PICK-UP/FEEDSYSTEM
IMAGE FORMATION
SYSTEM
LASER/SCANNER SYSTEM
ENGINE CONTROL
SYSTEM
Scanning mirror
Laser
diode
Scanner
motor
BD
circuit
Engine controller PCB
Face-up delivery slot
Fixing Pick-up
control
Developing
unit
Photo-
sensitive
drum
Primary
charging
roller
Cleaner
unit
Transfer
charging
roller
Manual feed slot
Multi-purpose tray
Face-down delivery tray
VIDEO CONTROL SYSTEM
Interface controller
PCB
Display
PCB