Ricoh iris Service Manual iris

Aficio Color 3006/4006/4106
(Iris/Lilac, A258/A259/A260)
Service Manual
Issued February 24, 1999, Ricoh CO., LTD.
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IMPORTANT SAFETY NOTICES

PREVENTION OF PHYSICAL INJURY
2. The wall outlet should be near the copier and easily accessible.
3. Note that some components of the copier and the paper tray unit are supplied with electrical voltage even if the main power switch is turned off.
4. If any adjustment or operation check has to be made with exterior covers off or open while the main switch is turned on, keep hands away from electrified or mechanically driven components.
5. If the Start key is pressed before the copier completes the warm-up period (the Start key starts blinking red and green alternatively), keep hands away from the mechanical and the electrical components as the copier starts making copies as soon as the warm-up period is completed.
6. The inside and the metal parts of the fusing unit become extremely hot while the copier is operating. Be careful to avoid touching those components with your bare hands.
HEALTH SAFETY CONDITIONS
1. Never operate the copier without the ozone filters installed.
2. Always replace the ozone filters with the specified ones at the specified intervals.
3. Toner and developer are non-toxic, but if you get either of them in your eyes by accident, it may cause temporary eye discomfort. Try to remove with eye drops or flush with water as first aid. If unsuccessful, get medical attention.
OBSERVANCE OF ELECTRICAL SAFETY STANDARDS
1. The copier and its peripherals must be installed and maintained by a customer service representative who has completed the training course on those models.
2. The NVRAM on the system control board has a lithium battery which can explode if replaced incorrectly. Replace the NVRAM only with an identical one. The manufacturer recommends replacing the entire NVRAM. Do not recharge or burn this battery. Used NVRAM must be handled in accordance with local regulations.
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1.
SAFETY AND ECOLOGICAL NOTES FOR DISPOSAL
Do not incinerate toner bottles or used toner. Toner dust may ignite suddenly when exposed to an open flame.
2. Dispose of used toner, developer, and organic photoconductors in accordance with local regulations. (These are non-toxic supplies.)
3. Dispose of replaced parts in accordance with local regulations.
4. When keeping used lithium batteries in order to dispos e of them later, do not put more than 100 batteries per sealed box. Storing larger numbers or not sealing them apart may lead to chemical reactions and heat build-up.

LASER SAFETY

The Center for Devices and Radiological Health (CDRH) prohibits the repair of laser-based optical units in the field. The optical housing unit can only be repaired in a factory or at a location with the requisite equipment. The laser subsystem is replaceable in the field by a qualified Customer Engineer. The laser chassis is not repairable in the field. Customer engineers are therefore directed to return all chassis and laser subsystems to the factory or service depot when replacement of the optical subsystem is required.
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WARNING Use of controls, or adjustment, or performance of procedures other than those specified in this manual may result in hazardous radiation exposure.
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WARNING Turn off the main switch before attempting any of the procedures in the Laser Unit section. Laser beams can seriously damage your eyes.
CAUTION MARKING:
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TABLE OF CONTENTS

1. OVERALL MACH INE INFORMATION........................................1-1
1.1 SPECIFICATIONS.................................................................................... 1-1
1.1.1 MACHINE CONFIGURATION ......................................................... 1-1
1.1.2 GENERAL SPECIFICATIONS......................................................... 1-2
1.1.3 PLATEN/ARDF ORIGINAL SIZE DETECTION................................ 1-6
1.1.4 COPY PAPER SIZE......................................................................... 1-7
1.1.5 APS PAPER SIZES AVAILABLE..................................................... 1-8
1.1.6 NOISE EMISSION........................................................................... 1-9
1.1.7 POWER CONSUMPTION.............................................................. 1-10
1.1.8 DISPLAY EDITOR SPECIFICATIONS.......................................... 1-10
1.2 MECHANISM OVERVIEW ..................................................................... 1-11
1.2.1 IMAGE GENERATION PROCESS................................................ 1-11
1.3 MAJOR UNIT LAYOUT AND PAPER FEED PATH................................ 1-14
1.4 PARTS LAYOUT .................................................................................... 1-17
1.4.1 MECHANICAL COMPONENT LAYOUT........................................ 1-17
1.4.2 ELECTRICAL COMPONENT LAYOUT......................................... 1-18
1.4.3 DRIVE LAYOUT............................................................................. 1-25
1.4.5 AIR FLOW ..................................................................................... 1-26
1.4.5 ELECTRICAL COMPONENT DESCRIPTIONS............................. 1-27
Printed Circuit Boards........................................................................ 1-27
Motors................................................................................................ 1-28
Fan Motors......................................................................................... 1-28
Sensors.............................................................................................. 1-29
Switches............................................................................................. 1-30
Clutches............................................................................................. 1-30
Solenoids........................................................................................... 1-31
Lamps................................................................................................ 1-31
Heaters .............................................................................................. 1-31
Thermistors........................................................................................ 1-31
Thermofuses...................................................................................... 1-31
Thermostat......................................................................................... 1-31
Counter.............................................................................................. 1-32
2. DETAILED DESCRIPTIONS .......................................................2-1
2.1 PROCESS CONTROL.............................................................................. 2-1
2.1.1 OVERVIEW ..................................................................................... 2-1
2.1.2 POTENTIAL CONTROL .................................................................. 2-2
Overview.............................................................................................. 2-2
Potential Control Timing....................................................................... 2-2
2.1.3 PROCESS CONTROL SELF CHECK ............................................. 2-4
Flow Chart............................................................................................ 2-4
Step 1: VSG Adjustment...................................................................... 2-5
Step 2: ID Sensor Pattern Generation.................................................. 2-5
I
Step 3: Sensor Pattern Potential Detection.......................................... 2-6
Step 4: Sensor Pattern Density Detection............................................ 2-7
Step 5: Toner Amount Calculation ....................................................... 2-8
Step 6: Development Potential Calculation.......................................... 2-9
Step 7: Selecting the Optimum VD, VB, VL .......................................2-10
2.1.4 PROCESS CONTROL γ CORRECTION....................................... 2-11
What is process control γ?................................................................. 2-11
How is it done?................................................................................... 2-11
Process control gamma correction timing.......................................... 2-12
2.2 TONER SUPPLY CONTROL.................................................................. 2-13
2.2.1 TONER SUPPLY CONTROL METHOD........................................ 2-13
2.2.2 FUZZY CONTROL MODE............................................................. 2-13
2.2.3 VSP DETECTION FOR TONER SUPPLY CONTROL .................. 2-14
2.2.4 CALCULATING THE AMOUNT OF TONER ON THE DRUM....... 2-14
Fuzzy Logic Algorithm........................................................................ 2-14
Image Area Ratio............................................................................... 2-15
2.2.5 FIXED SUPPLY MODE ................................................................. 2-15
2.2.6 TONER SUPPLY IN ABNORMAL SENSOR CONDITIONS..........2-15
2.2.7 DETECTING TONER NEAR END/END......................................... 2-16
Toner Near-end.................................................................................. 2-16
Toner End.......................................................................................... 2-16
Toner near end detection................................................................... 2-17
Toner end detection........................................................................... 2-17
Toner end recovery............................................................................ 2-18
Toner replenishment confirmation mode............................................ 2-18
2.3 DRUM UNIT............................................................................................ 2-19
2.3.1 OVERVIEW ................................................................................... 2-19
2.3.2 DRIVE MECHANISM..................................................................... 2-20
2.3.3 DRUM CHARGE............................................................................ 2-21
2.3.4 DRUM CLEANING......................................................................... 2-22
2.3.5 PCC............................................................................................... 2-22
2.3.6 QUENCHING................................................................................. 2-23
2.3.7 CARRIER CATCHER .................................................................... 2-23
2.4 SCANNER UNIT..................................................................................... 2-24
2.4.1 OVERVIEW ................................................................................... 2-24
2.4.2 SCANNER..................................................................................... 2-25
2.4.3 SCANNER DRIVE ......................................................................... 2-26
2.4.4 COLOR CCD ................................................................................. 2-27
2.4.5 WHITE PLATE SCANNING........................................................... 2-28
2.4.6 SCANNER IPU BOARD................................................................. 2-28
2.4.7 ORIGINAL SIZE DETECTION....................................................... 2-29
2.4.8 OTHERS........................................................................................ 2-31
Anti-condensation Heater................................................................... 2-31
Fans................................................................................................... 2-31
2.5 IMAGE PROCESSING ........................................................................... 2-32
2.5.1 OVERVIEW ................................................................................... 2-32
2.5.2 SCANNER SECTION BLOCK DIAGRAM...................................... 2-33
2.5.3 SCANNER SECTION .................................................................... 2-34
Photoelectric Conversion (by the CCD) ............................................. 2-34
II
Signal Processing (in the Analog ASIC)............................................. 2-34
A/D Conversion.................................................................................. 2-34
Shading Circuit................................................................................... 2-35
D/A Conversion.................................................................................. 2-37
Scan Line Correction.......................................................................... 2-37
2.5.4 IPU SECTION BLOCK DIAGRAM................................................. 2-38
2.5.5 IPU SECTION................................................................................ 2-39
Picture Element Correction and Scanner Gamma Correction............ 2-39
ACS (Auto Color Selection)................................................................ 2-41
Auto Letter/Photo Separation............................................................. 2-42
Filtering and Color Conversion........................................................... 2-44
Changes in UCR Ratio with Image Density and Copy Mode ............. 2-50
UCA (Under Color Addition)............................................................... 2-50
Main Scan Magnification.................................................................... 2-51
Mirror Image....................................................................................... 2-51
Gamma (γ) Correction (Printer Gamma)............................................ 2-52
Area Editing........................................................................................ 2-55
CPU ................................................................................................... 2-55
IPU Board Test................................................................................... 2-55
2.6 LASER EXPOSURE............................................................................... 2-56
2.6.1 OVERVIEW ................................................................................... 2-56
2.6.2 OPTICAL PATH............................................................................. 2-57
Overview............................................................................................ 2-57
F-theta Lenses and the BTL............................................................... 2-59
Laser Synchronizing Detector Boards................................................ 2-60
Gradation Control (Laser Pulse Width and Laser Power Modulation) 2-61
600 DPI Writing.................................................................................. 2-62
Auto Power Control (APC)................................................................. 2-63
LD Safety Switches............................................................................ 2-64
2.6 DEVELOPMENT UNIT........................................................................... 2-65
2.6.1 OVERVIEW ................................................................................... 2-65
2.6.2 REVOLVER MECHANISM............................................................. 2-66
Overview............................................................................................ 2-66
Revolver Drive.................................................................................... 2-67
Revolver Home Position Detection..................................................... 2-68
2.6.3 DEVELOPMENT MECHANISMS................................................... 2-69
Overview............................................................................................ 2-69
Development Drive............................................................................. 2-70
Developer Agitation............................................................................ 2-70
Toner Agitation................................................................................... 2-71
Development Bias.............................................................................. 2-72
Toner Supply Mechanism ..................................................................2-73
Toner Cartridge Detection.................................................................. 2-74
Incorrect Toner Installation Prevention............................................... 2-74
Toner End Detection.......................................................................... 2-75
2.7 TRANSFER BELT UNIT......................................................................... 2-76
2.7.1 OVERVIEW ................................................................................... 2-76
2.7.2 BELT TRANSFER MECHANISMS ................................................ 2-77
Transfer Belt Drive............................................................................. 2-77
III
Transfer Belt Release Lever............................................................... 2-78
Belt Transfer Bias............................................................................... 2-79
Belt Mark Detection............................................................................ 2-80
Transfer Belt Cleaning Mechanism.................................................... 2-81
2.7.3 PAPER TRANSFER MECHANISM................................................ 2-85
Paper Transfer Unit Contact/Release Mechanism............................. 2-85
Paper Transfer Bias Roller Drive........................................................ 2-86
Paper Transfer Bias Roller Cleaning.................................................. 2-87
Paper Transfer Bias........................................................................... 2-88
2.7.4 PAPER SEPARATION MECHANISM............................................ 2-90
2.8 PAPER FEED AND REGISTRATION..................................................... 2-91
2.8.1 OVERVIEW ................................................................................... 2-91
2.8.2 PAPER TRAY................................................................................ 2-92
Paper Feed/Separation...................................................................... 2-92
Separation and Pick-Up Roller Release............................................. 2-92
Paper Lift............................................................................................ 2-93
Paper End Detection..........................................................................2-94
Paper Size Setting ............................................................................. 2-94
Tray Paper Height Sensor.................................................................. 2-95
2.8.3 BY-PASS TRAY............................................................................. 2-96
By-pass Table Mechanism................................................................. 2-96
Paper Feed/Separation...................................................................... 2-96
Paper End Detection..........................................................................2-97
Paper Size Detection ......................................................................... 2-98
Pick-up Roller..................................................................................... 2-99
2.8.4 REGISTRATION MECHANISM AND PAPER FEED DRIVE......... 2-99
2.9 PAPER TRANSPORT, FUSING, AND PAPER EXIT ........................... 2-100
2.9.1 MAJOR COMPONENTS.............................................................. 2-100
2.9.2 DRIVE MECHANISM................................................................... 2-101
2.9.3 FUSING UNIT.............................................................................. 2-102
Fusing Mechanism........................................................................... 2-102
Fusing Temperature Control............................................................ 2-102
Fusing/Pressurization Mechanism................................................... 2-103
Oil Supply Mechanism ..................................................................... 2-104
Cleaning Mechanism........................................................................ 2-105
2.9.4 INVERTER AND PAPER EXIT MECHANISMS........................... 2-106
Paper Exit......................................................................................... 2-106
Junction Gate Mechanism (A259/A260 Only).................................. 2-106
Paper Exit Door Mechanism (A259/A260 Only)............................... 2-107
2.10 DUPLEX TRAY (A259/A260 COPIERS ONLY)..................................2-108
2.10.1 OVERVIEW ............................................................................... 2-108
2.10.2 DRIVE MECHANISM................................................................. 2-109
2.10.3 PAPER FEED INTO THE DUPLEX TRAY................................. 2-110
1. Duplex Stacking........................................................................... 2-110
2. Paper Feed from the Duplex Tray................................................2-110
3. Duplex Entrance To Duplex Tray................................................. 2-111
2.10.4 JOGGER MECHANISM............................................................. 2-112
2.10.5 PAPER FEED FROM THE DUPLEX TRAY............................... 2-113
Bottom Plate Lift Mechanism ........................................................... 2-113
IV
Paper Feed-out mechanism............................................................. 2-114
2.11 OTHERS............................................................................................. 2-115
2.11.1 SYSTEM CONFIGURATION..................................................... 2-115
2.11.2 POWER STATES ...................................................................... 2-116
Energy Saver Mode ......................................................................... 2-116
Power-off (Sleep) State.................................................................... 2-116
Main Power Switch Off State ........................................................... 2-117
Power State Transition Diagram...................................................... 2-117
2.11.3 TOUCH PANEL (A259/A260 MACHINES ONLY)...................... 2-118
2.11.4 BUS SWITCH BOARD (OPTIONAL)......................................... 2-119
3. INSTALLATION PROCEDURE...................................................3-1
3.1 INSTALLATION REQUIREMENTS .......................................................... 3-1
3.1.1 DIMENSIONS.................................................................................. 3-2
3.1.2 ENVIRONMENTAL REQUIREMENTS............................................ 3-3
3.1.3 MINIMUM SPACE REQUIREMENTS.............................................. 3-5
3.1.4 POWER REQUIREMENTS.............................................................. 3-6
3.2 COPIER INSTALLATION.......................................................................... 3-7
3.2.1 ACCESSORY CHECK..................................................................... 3-7
3.2.2 COPIER INSTALLATION PROCEDURE......................................... 3-8
Tape Removal...................................................................................... 3-8
Removing the Inner Transfer Cover and Paper Transfer
Locking Screw.................................................................................. 3-10
Developer Installation......................................................................... 3-12
Pressure Release Lever Set-up......................................................... 3-17
Installing Fusing Silicone Oil.............................................................. 3-18
Initialization and Function Checks...................................................... 3-19
Setting the Tray Paper Size............................................................... 3-20
Setting the Language and Unit of Measurement................................ 3-21
Resetting the Counter........................................................................ 3-21
3.2.2 RELOCATION PROCEDURE........................................................ 3-22
3.3 PAPER TRAY UNIT (A832/A833)........................................................... 3-23
3.3.1 ACCESORY CHECK..................................................................... 3-23
3.3.2 INSTALLATION............................................................................. 3-24
TRAY HEATER (OPTION)................................................................. 3-27
3.4 PLATEN COVER (A749-01)................................................................... 3-28
3.5 ARDF (A663).......................................................................................... 3-29
3.5.1 ACCESSORY CHECK................................................................... 3-29
3.5.2 INSTALLATION............................................................................. 3-30
3.6 20-BIN SORTER STAPLER (A834)........................................................ 3-31
3.6.1 ACCESSORY CHECK................................................................... 3-31
3.6.2 INSTALLATION............................................................................. 3-32
3.7 10-BIN SORTER STAPLER (A555)........................................................ 3-36
3.7.1 ACCESSORY CHECK................................................................... 3-36
3.7.2 INSTALLATION............................................................................. 3-37
3.8 3-BIN SORTER (A849)........................................................................... 3-42
V
3.8.1 ACCESSORY CHECK................................................................... 3-42
3.8.2 INSTALLATION............................................................................. 3-43
3.9 FILM PROJECTOR TABLE (A702-19)................................................... 3-45
3.10 FILM PROJECTOR UNIT (A846) ......................................................... 3-47
3.10.1 ACCESSORY CHECK................................................................. 3-47
3.10.2 INSTALLATION............................................................................ 3-48
3.11 CONTROLLER INTERFACE TYPE E (A848)....................................... 3-55
3.12 OTHERS............................................................................................... 3-59
3.12.1 ORIGINAL TABLE INSTALLATION PROCEDURE..................... 3-59
3.12.2 KEY COUNTER HOLDER INSTALLATION PROCEDURE......... 3-60
4. SERVICE TABLES......................................................................4-1
4.1 SERVICE PROGRAM (SP) MODES........................................................ 4-1
4.1.1 HOW TO ENTER SP MODE............................................................ 4-1
4.2 SP MODE TYPES .................................................................................... 4-1
4.3 SP MODE TABLE..................................................................................... 4-2
4.4 SP MODE ADDITIONAL NOTES .............................................................4-3
4.4.1 SP5-804 OUTPUT CHECK............................................................ 4-3
4.4.2 SP5-803 INPUT CHECK.................................................................. 4-5
Printer .................................................................................................. 4-5
Sorter................................................................................................... 4-7
ARDF................................................................................................... 4-8
4.4.3 SP5-955-018 TEST PATTERN SELECTION................................... 4-8
4.4.4 5-955-001 LD_PWM (DOT, LINE)................................................... 4-8
4.4.5 5-955-002 TO 5-955-016 LD_PWM (16-GRADATION)................... 4-9
4.4.6 5-995-017 LD_PWM (COLOR PATCHES)...................................... 4-9
4.5 USER TOOL...........................................................................................4-10
4.5.1 USER TOOL MENU....................................................................... 4-10
System settings.................................................................................. 4-10
COPY FEATURES............................................................................. 4-11
4.5.2 SYSTEM SETTINGS..................................................................... 4-12
4.5.3 COPY FEATURES......................................................................... 4-16
General Features............................................................................... 4-16
Image Adjustment.............................................................................. 4-19
Set Favorite Keys............................................................................... 4-21
Special Modes.................................................................................... 4-21
4.6 TP/SW/LED/FUSE.................................................................................. 4-22
4.6.1 MAIN CONTROL BOARD TEST POINTS..................................... 4-22
4.6.2 SCANNER IPU BOARD TEST POINTS........................................ 4-23
4.6.3 LD MAIN CONTROL BOARD TEST POINTS................................ 4-24
4.6.4 I/O CONTROL BOARD TEST POINTS ......................................... 4-25
4.6.5 SWITCH SPECIFICATIONS.......................................................... 4-28
Scanner IPU Board............................................................................ 4-28
4.6.6 LED SPECIFICATIONS.................................................................4-28
4.6.7 FUSE SPECIFICATIONS .............................................................. 4-29
PSU (US model)................................................................................. 4-29
PSU (European/Asian Model)............................................................ 4-30
VI
5. PREVENTIVE MAINTENANCE...................................................5-1
5.1 PM PROCEDURES.................................................................................. 5-1
5.1.1 PM-RELATED COUNTERS............................................................. 5-1
5.1.2 REGULAR PREVENTIVE MAINTENANCE FLOW DIAGRAM........ 5-3
5.2 REGULAR PM ITEMS.............................................................................. 5-7
Regular PM Table................................................................................ 5-7
6. REPLACEMENT AND ADJUSTMENT ........................................ 6-1
6.1 COVERS, FANS, AND FILTERS.............................................................. 6-1
6.1.1 FRONT, INNER, AND INNER TRANSFER COVERS ..................... 6-1
6.1.2 REAR COVERS............................................................................... 6-2
6.1.3 RIGHT COVERS.............................................................................. 6-3
6.1.4 LEFT COVERS................................................................................ 6-3
6.1.5 EXPOSURE GLASS........................................................................ 6-4
6.1.6 OPERATION PANEL....................................................................... 6-4
6.1.7 UPPER COVERS ............................................................................ 6-4
6.1.8 USED TONER TANK....................................................................... 6-5
6.1.9 CHARGE CORONA FAN FILTER ................................................... 6-5
6.1.10 MAIN EXHAUST FAN FILTER....................................................... 6-6
6.1.11 SCANNER EXHAUST FAN FILTER.............................................. 6-6
6.1.12 MAIN EXHAUST FAN.................................................................... 6-7
6.2 DRUM UNIT.............................................................................................. 6-8
6.2.1 PULLING OUT THE REVOLVER/DRUM DRAWER...................... 6-10
6.2.2 DRUM REPLACEMENT................................................................ 6-12
6.2.3 CLEANING BLADE AND PCC WIRE REPLACEMENT................. 6-14
6.2.4 CLEANING BRUSH REPLACEMENT........................................... 6-15
6.2.5 LUBRICANT BAR REPLACEMENT.............................................. 6-16
6.2.6 CHARGE CORONA GRID AND WIRE REPLACEMENT.............. 6-17
6.2.7 POTENTIAL SENSOR REPLACEMENT....................................... 6-18
6.3 SCANNER UNIT..................................................................................... 6-19
6.3.1 EXPOSURE LAMP REPLACEMENT............................................ 6-19
6.3.2 SBU REPLACEMENT.................................................................... 6-20
6.3.3 SCANNER IPU BOARD REPLACEMENT..................................... 6-21
6.3.4 SCANNER WIRE/SCANNER MOTOR REPLACEMENT .............. 6-22
6.3.5 APS SENSORS............................................................................. 6-26
6.3.6 SCANNER HP SENSOR............................................................... 6-27
6.4 COPY IMAGE ADJUSTMENT................................................................ 6-28
6.4.1 PRINTER GAMMA ADJUSTMENT................................................ 6-28
Setting the KCMY standard values.................................................... 6-28
Gamma Data Print Out....................................................................... 6-28
KCMY color balance adjustment........................................................ 6-28
Adjustment procedure........................................................................ 6-29
Standard Copy Quality....................................................................... 6-30
6.4.2 ACC TARGET ADJUSTMENT....................................................... 6-31
6.4.3 MAIN SCAN DOT POSITION CORRECTION............................... 6-32
VII
6.5 LASER OPTICS SECTION..................................................................... 6-34
6.5.1 POLYGON MIRROR MOTOR REPLACEMENT............................ 6-35
6.5.2 LASER SYNCHRONIZING DETECTOR BOARD AND LD UNIT
REPLACEMENT...................................................................................... 6-37
6.5.3 SQUARENESS ADJUSTMENT..................................................... 6-38
6.6 DEVELOPMENT UNIT........................................................................... 6-40
6.6.1 REPLACING THE DEVELOPER................................................... 6-40
Developer Collection Procedure......................................................... 6-40
Installing New Developer ................................................................... 6-43
6.6.2 POST DEVELOPER COLLECTION PROCEDURE....................... 6-46
6.6.3 DEVELOPMENT UNIT REPLACEMENT....................................... 6-47
6.6.4 TONER COLLECTION TRAY CLEANING..................................... 6-48
6.7 TRANSFER BELT UNIT......................................................................... 6-49
6.7.1 TRANSFER BELT SECTION......................................................... 6-49
Transfer Belt and Cleaning Unit......................................................... 6-49
Cleaning Blade Replacement............................................................. 6-52
Lubricant Bar and Lubricant Brush Replacement............................... 6-53
6.7.2 PAPER TRANSFER UNIT............................................................. 6-54
Lubricant Bar And Blade Replacement.............................................. 6-54
Paper Separation Corona Wire Replacement.................................... 6-54
Transfer Roller Replacement............................................................. 6-55
6.8 PAPER FEED AND REGISTRATION SECTION.................................... 6-56
6.8.1 BY-PASS FEED TABLE REMOVAL.............................................. 6-56
6.8.2 BY-PASS PAPER WIDTH DETECTION BOARD REPLACEMENT6-56
6.8.3 BY-PASS FEED, PICK-UP AND SEPARATION ROLLERS,
AND TORQUE LIMITER REPLACEMENT.................................... 6-57
6.8.4 BY-PASS FEED UNIT REPLACEMENT........................................ 6-58
6.8.5 REGISTRATION SENSOR REPLACEMENT................................ 6-58
6.8.6 VERTICAL TRANSPORT DOOR REPLACEMENT....................... 6-59
6.8.7 PAPER TRAY PICK-UP, PAPER FEED, AND SEPARATION
ROLLER REPLACEMENT............................................................. 6-59
6.8.8 PAPER FEED UNIT AND CLUTCH REPLACEMENT................... 6-60
6.8.9 COPY IMAGE AREA ADJUSTMENT ............................................ 6-61
Preparation ........................................................................................ 6-61
Leading Edge Registration................................................................. 6-62
Side-to-side Registration.................................................................... 6-63
6.9 PAPER TRANSPORT, FUSING, AND PAPER EXIT SECTIONS.......... 6-64
6.9.1 FUSING UNIT REMOVAL ............................................................. 6-64
6.9.2 TRANSPORT UNIT REMOVAL..................................................... 6-65
6.9.3 FUSING UNIT TOP COVER REMOVAL .......................................6-66
6.9.4 OIL SUPPLY PAD AND OIL BLADE REPLACEMENT.................. 6-67
6.9.5 HOT ROLLER THERMOFUSE REPLACEMENT.......................... 6-68
6.9.6 FUSING UNIT DISASSEMBLY...................................................... 6-68
6.9.7 CLEANING ROLLER SCRAPER CLEANING................................ 6-69
6.9.8 HOT ROLLER THERMISTOR REPLACEMENT............................ 6-70
6.9.9 HOT ROLLER FUSING LAMP REPLACEMENT........................... 6-71
6.9.10 HOT ROLLER AND CLEANING ROLLER REPLACEMENT
AND CLEANING........................................................................... 6-72
VIII
6.9.11 PRESSURE ROLLER AND PRESSURE ROLLER FUSING
LAMP........................................................................................... 6-73
6.9.12 PRESSURE ROLLER THERMOFUSE AND THERMISTOR
REPLACEMENT.......................................................................... 6-74
6.9.13 NIP BAND WIDTH ADJUSTMENT.............................................. 6-75
6.9.14 CAUTIONS TO BE TAKEN WHEN USING A FUSING UNIT
THAT HAS BEEN IN STOCK FOR A LONG PERIOD.................. 6-76
6.10 DUPLEX UNIT...................................................................................... 6-77
6.10.1 DUPLEX UNIT REMOVAL........................................................... 6-77
6.10.2 SEPARATION ROLLER REPLACEMENT................................... 6-77
6.10.3 FEED ROLLER REPLACEMENT................................................ 6-78
6.10.4 DUPLEX FEED MOTOR REPLACEMENT.................................. 6-79
6.11 SYSTEM AND ELECTRONICS............................................................ 6-81
6.11.1 IPU PROGRAM DOWNLOADING............................................... 6-81
6.11.2 MAIN PROGRAM DOWNLOADING............................................ 6-82
6.11.3 NV-RAM UPLOADING AND DOWNLOADING............................ 6-83
Upload/Download Procedure............................................................. 6-83
6.11.4 RAM CLEAR................................................................................ 6-84
RAM Clear Procedure........................................................................ 6-84
Precautions when replacing the NV-RAM.......................................... 6-85
6.11.5 TOUCH PANEL CALIBRATION (A259/A260 ONLY)................... 6-86
7. TROUBLESHOOTING.................................................................7-1
7.1 SERVICE CALL (SC) ERRORS ............................................................... 7-1
7.1.1 SC TYPES AND RESETTING PROCEDURES............................... 7-1
7.2 SC CODE TABLE..................................................................................... 7-2
7.3 PROCESS CONTROL ERROR CONDITIONS ........................................ 7-3
7.3.1 PROCESS CONTROL SELF-CHECK RESULTS (SP3-975-00)..... 7-3
7.3.2 DEVELOPER SETUP RESULTS (SP3-964-00).............................. 7-4
7.3.3 SELF-CHECK PROCESS CONTROL RELATED SCS ................... 7-5
7.4 DRUM LIGHT FATIGUE........................................................................... 7-6
IX
OPTIONS
ARDF (A663)
1. SPECIFICATIONS.................................................................A663-1
2. COMPONENT LAYOUT........................................................A663-2
2.1 MECHANICAL COMPONENTS..........................................................A663-2
2.2 ELECTRICAL COMPONENTS...........................................................A663-3
3. ELECTRICAL COMPONENT DESCRIPTION.......................A663-4
4. DETAILED DESCRIPTIONS.................................................A663-5
4.1 ORIGINAL PICK-UP MECHANISM....................................................A663-5
4.2 SEPARATION AND PAPER FEED MECHANISM..............................A663-6
4.3 FRICTION BELT DRIVE MECHANISM..............................................A663-7
4.4 ORIGINAL SIZE DETECTION............................................................A663-8
4.5 PAPER TRANSPORT MECHANISM..................................................A663-9
4.6 THICK/THIN ORIGINAL MODES ..................................................... A663-10
4.7 ORIGINAL FEED-OUT MECHANISM...............................................A663-11
4.8 TWO-SIDED ORIGINAL FEED MECHANISM..................................A663-12
5. TIMING CHARTS ................................................................A663-13
5.1 A4 SIDEWAYS: 1 SIDED ORIGINAL ...............................................A663-13
5.2 COMBINE 2 ORIGINAL MODE........................................................A663-14
5.3 A4 SIDEWAYS: DUPLEX.................................................................A663-15
6. SERVICE TABLES..............................................................A663-16
6.1 DIP SWITCHES................................................................................A663-16
6.2 VARIABLE RESISTORS...................................................................A663-17
6.3 LED...................................................................................................A663-17
6.4 FUSE................................................................................................A663-17
7. REPLACEMENT A N D ADJUSTMENT................................A663-18
7.1 TRANSPORT BELT REPLACEMENT..............................................A663-18
7.2 FEED ROLLER REPLACEMENT..................................................... A663-19
7.3 FRICTION BELT REPLACEMENT...................................................A663-20
7.4 ORIGINAL SET AND WIDTH SENSOR REPLACEMENT................A663-21
7.5 VERTICAL REGISTRATION ADJUSTMENT...................................A663-22
7.5.1 ONE SIDED THIN ORIGINAL MODE......................................A663-22
7.5.2 TWO SIDED ORIGINAL MODE...............................................A663-23
7.6 SIDE-TO-SIDE REGISTRATION (DF POSITIONING)
ADJUSTMENT..................................................................................A663-24
X
PAPER TRAY UNIT (A832/A833)
1. PRODUCT OVERVIEW..........................................................
1.1 SPECIFICATIONS..............................................................................A833-1
1.2 COMPONENT DESCRIPTION...........................................................A833-1
1.2.1 PAPER FEED MECHANISM.....................................................A833-1
1.3 COMPONENT LAYOUTS...................................................................A833-2
1.3.1 ELECTRICAL COMPONENT LAYOUT.....................................A833-2
1.3.2 DRIVE LAYOUT.........................................................................A833-3
1.3.3 DISASSEMBLY AND ADJUSTMENT PROCEDURES..............A833-4
(1) Pick-up, paper feed, and separation rollers..............................A833-4
(2) Bank paper feed and tray lift motors......................................... A833-4
(3) Paper feed clutch......................................................................A833-5
(3) Relay clutch..............................................................................A833-5
(4) Paper feed unit.........................................................................A833-6
20-BIN SORTER (A834)
1. OVERALL MAC HINE INFORMATION...................................
1.1 SPECIFICATIONS..............................................................................A834-1
1.2 COMPONENT LAYOUT.....................................................................A834-3
1.2.1 MECHANICAL COMPONENT LAYOUT .................................... A834-3
1.2.2 DRIVE LAYOUT.........................................................................A834-4
1.2.3 ELECTRICAL COMPONENT DESCRIPTION...........................A834-5
A833-
A834-
1
1
2. DETAILED DESCRIPTIONS ..................................................
2.1 BASIC OPERATION...........................................................................A834-6
2.1.1 NORMAL MODE AND SORT/STACK MODE............................A834-6
Normal (Proof) Mode......................................................................A834-6
Sort Mode ......................................................................................A834-6
Stack Mode....................................................................................A834-7
2.1.2 STAPLE MODE.........................................................................A834-8
Mechanism.....................................................................................A834-8
Automatic Stapling.........................................................................A834-8
Manual Stapling .............................................................................A834-8
2.1.3 BIN DRIVE MECHANISM..........................................................A834-9
2.1.4 BIN HOME POSITION............................................................. A834-10
2.1.5 JOGGER MECHANISM...........................................................A834-11
2.1.6 GRIP ASSEMBLY....................................................................A834-12
2.1.7 STAPLER UNIT.......................................................................A834-13
2.1.8 STAPLER SWITCH .................................................................A834-14
Staple Mode Disabling Conditions...............................................A834-14
2.1.9 PAPER FEED AND MISFEED DETECTION TIMING..............A834-15
Proof ModeA4 sideways, five copies, 150 mm/s..........................A834-15
Sorter ModeA4 sideways, two copies a of two-page original,
150 mm/s.....................................................................................A834-15
A834-
6
XI
Staple ModeA4 sideways, two copies of a two-page original, after
sorting, 150 mm/s.........................................................................A834-16
2.1.10 JAM DETECTION..................................................................A834-17
Paper JamA4 sideways................................................................A834-17
Staple Jam...................................................................................A834-17
3. REPLACEMENT AND ADJUSTEMENT ..............................
3.1 EXTERIOR COVER REMOVAL.......................................................A834-18
3.1.1 FRONT COVER.......................................................................A834-18
3.1.2 REAR COVER.........................................................................A834-18
3.1.3 TOP COVER............................................................................A834-18
3.1.4 LOWER COVER......................................................................A834-18
3.2 STAPLER UNIT REMOVAL..............................................................A834-19
3.3 GRIP ARM REPLACEMENT............................................................A834-20
3.4 BIN REMOVAL.................................................................................A834-21
3.5 TRANSPORT MOTOR REMOVAL...................................................A834-22
10-BIN SORTER (A555)
A834-
18
1. SPECIFICATIONS.................................................................A555-1
2. COMPONENT LAYOUT........................................................A555-3
2.1 MECHANICAL COMPONENT LAYOUT.............................................A555-3
2.2 DRIVE LAYOUT .................................................................................A555-4
2.3 ELECTRICAL COMPONENT DESCRIPTION....................................A555-5
3. BASIC OPERATION...............................................................
3.1 NORMAL MODE AND SORT/STACK MODE.....................................A555-6
3.2 STAPLE MODE..................................................................................A555-8
3.3 BIN DRIVE MECHANISM.................................................................A555-10
3.4 BIN HOME POSITION......................................................................A555-11
3.5 JOGGER MECHANISM....................................................................A555-12
3.6 GRIP ASSEMBLY.............................................................................A555-13
3.7 STAPLER UNIT................................................................................A555-14
3.8 STAPLER SWITCH..........................................................................A555-15
3.9 PAPER FEED AND MISFEED DETECTION TIMING ......................A555-16
3.10 JAM DETECTION...........................................................................A555-18
A555-
6
4. SERVICE TABLES...............................................................
4.1 DIP SWITCHES................................................................................A555-19
4.2 TEST POINTS..................................................................................A555-20
4.3 LED...................................................................................................A555-20
4.4 VARIABLE RESISTOR.....................................................................A555-20
5. REPLACEMENT AND ADJUSTMENT .................................
5.1 EXTERIOR COVER REMOVAL.......................................................A555-21
5.2 STAPLE UNIT REMOVAL................................................................A555-21
5.3 GRIP ARM REPLACEMENT............................................................A555-22
XII
A555-
A555-
19
21
5.4 BIN REPLACEMENT........................................................................A555-23
5.5 TRANSPORT MOTOR REPLACEMENT..........................................A555-24
5.6 BIN JAM SENSOR ADJUSTMENT ..................................................A555-25
3-BIN SORTER (A849)
1. SPECIFICAT IONS..................................................................
2. COMPONENT LAYOUT.........................................................
2.1 MECHANICAL COMPONENT LAYOUT.............................................A849-2
2.2 DRIVE LAYOUT .................................................................................A849-3
2.3 ELECTRICAL COMPONENT DESCRIPTION....................................A849-4
3. DETAILED SECTION DESCRIPTIONS..................................
3.1 BASIC OPERATION...........................................................................A849-5
3.1.1 FACE-UP MODE .......................................................................A849-5
3.1.2 FACE-DOWN MODE.................................................................A849-6
3.2 1ST BIN UP/DOWN MECHANISM.....................................................A849-7
3.3 1ST BIN SIDE-TO-SIDE SHIFT MECHANISM...................................A849-8
3.4 PAPER FEED AND MISFEED DETECTION TIMING ........................A849-9
3.5 JAM DETECTION.............................................................................A849-11
4. REPLACEMENT AND ADJUSTMENT .................................
4.1 EXTERIOR COVER AND BIN REMOVAL........................................A849-12
4.2 TRAY LIFT/SHIFT MOTOR ASSEMBLY REMOVAL .......................A849-13
4.3 ENTRANCE MOTOR REPLACEMENT............................................A849-14
4.4 EXIT MOTOR REPLACEMENT........................................................A849-15
4.5 STACK HEIGHT SENSOR AND 1ST EXIT
SENSOR REPLACEMENT...............................................................A849-16
4.6 2ND / 3RD EXIT SENSOR AND INVERTER
SENSOR REPLACEMENT...............................................................A849-18
A849­A849-
A849-
A849-
1 2
5
12
FPU (A846)
1. SPECIFICAT IONS..................................................................
A846-
2. ELECTRICAL COMPONENT LAYOUT
AND DESCRIPTIONS...........................................................
3. SECTIONAL DESCRIPTIONS................................................
3.1 OVERVIEW ........................................................................................ A846-3
3.2 SHADING ...........................................................................................A846-4
3.3 MIRROR UNIT....................................................................................A846-5
XIII
A846­A846-
1
2 3
APPENDIX
1. TIMMING CHART
A4 SIZE B/W MODE......................................................................................1
A4 SIZE FULL COLOR MODE......................................................................2
A3 SIZE B/W MODE......................................................................................3
A3 SIZE FULL COLOR MODE......................................................................4
2. SP MODE TABLE
3. SC CODE TABLE
XIV
24 February, 1999 SPECIFICATIONS
0
9

1. OVERALL MACHINE INFORMATION

1.1 SPECIFICATIONS

1.1.1 MACHINE CONFIGURATION

A258 A259 A260
Operation Panel
Paper Tray Unit
Edit Function
Sorter/Stapler
A555
40-digit 4-line LCD Hard Key Type
500 sheets Duplex
No No Yes
Platen Cover
A749-00
Overall
Information
144 mm x 192 mm (10.4 inch) Color Touch Panel Display
ARDF
A663
A834
A849
Copier
Paper Tray Unit (500 sheets per tray)
A833
A832
FPU A846
FPU Table A7
2-1
I/F A848
A259V501.WMF
1-1
SPECIFICATIONS 24 February, 1999

1.1.2 GENERAL SPECIFICATIONS

Configuration: Desktop Copy Process: Dry electrostatic transfer system Resolution:400 dpi; Printer mode 600 dpi Gradations: 256 gradations Originals: Sheet/Book/Object Original Size: Maximum 11" x 17" /A3 Copy Paper Size:
Maximum Minimum
Paper Tray Feed (A258 only)
Bypass Feed
Copy Paper Weight:
Paper Tray Feed Bypass Feed Auto Duplex Tray
11" x 17" /A3 5 12" x 18"/305 mm x 457 mm A6(L)
17 to 28 lbs. 64 to 105 g/m 14 to 43 lbs. 52 to 160 g/m 17 to 28 lbs. 64 to 105 g/m
2 2 2
1/2
x 8
/A5(L)
1/2
Reproduction Ratios:
8
" x 11"LT/11" x 17"DLT
1/2
A4/A3 version
version Enlargement Full size Reduction Programmable
121, 129, 155, 200, 400% 115, 122, 141, 200, 400% 100% 100% 25, 50, 65, 73, 78, 85, 93% 25, 50, 65, 71, 75, 82, 93% 2 user ratios 2 user ratios
Zoom: From 25% to 400 % in 1% steps.
1-2
24 February, 1999 SPECIFICATIONS
Copying Speed:
8
" x 11" (S) /A4 11" x 17"/A3
1/2
Normal Mode
Full Color (4 scans) 6 cpm 3 cpm Single Color (C, M Y, K) A258: 21 cpm
A259/260: 28 cpm
A258: 11 cpm
A259/260: 14 cpm Single Color (B, G) 9 cpm 4.5 cpm Single Color (R) 7 cpm 3.5 cpm
OHP/Thick Paper Mode
Full Color (4 scans) 3 cpm 1.5 cpm Single Color (C, M Y, K) 5 cpm 2.5 cpm Single Color (G, B) 4 cpm 2 cpm Single Color (R) 3.5 cpm 1.5 cpm
Duplexing: Same as Normal Mode speed in the above table Printer Speed: 2/3 the speeds shown in the above table
First Copy Time (A258/259/260):
Overall
Information
8
" x 11" (S) /A4
1/2
Normal Mode
Full Color (4 scans) 22.4 seconds Single Color (K) 8 seconds Single Color (C, M, Y) 10 seconds Single Color (B, G, R) 16 seconds
OHP/Thick Paper Mode
Full Color (4 scans) 35 seconds Single Color (K) 23 seconds Single Color (C, M, Y) 25 seconds Single Color (B, G, R) 27 seconds
Warm-up Time: Approx. 7 minutes (at 68°F / 20°C)
1-3
SPECIFICATIONS 24 February, 1999
Duplexing:
Basic Manual Duplex
Model (A258):
Basic Auto Duplex
Model (A259):
Edit Auto Duplex Model
(A260):
Manual duplexing in full color and single color modes Manual & auto duplexing in full color and single color modes Manual & auto duplexing in full color and single color modes
Duplexing can be done on 64-105 g/m2 paper. Manual duplexing can be done through the
bypass table only, and the user should press the Duplex Side 2 key before copying the reverse side.
Non-Reproduction Area:
Leading Edge: Side:
0.2" ± 0.08" (5 mm ± 2 mm)
0.08" ± 0.08" (2 mm ± 2 mm)/ Total less than 0.16" (4 mm)
Trailing Edge:
2.0 mm + 2.0/-1.5 mm Copy Number Input: Number keys, 1 to 99 Copy Number Input
(Auto Duplex):
Number keys Single Color - 1 to 50: smaller than A3, 11" x 17"
1 to 30: A3, 11" x17"
Full Color 1 to 20: all sizes Image Density: Auto/Manual (9 steps) Automatic Reset: Yes (10 to 990 seconds or Off) Paper Capacity: Tray:
500 sheets x 1 tray (Basic Manual Duplex Model: A258)
Bypass:
Normal paper (80 g/m2/20 lb) 50 sheets OHP 20 sheets
Adhesive paper 1 sheet Toner Replenishment: Toner Addition (K, Y, C, M) (220 g/cartridge) Copy Tray Capacity: 100 sheets (11" x 17"/A3 and smaller) Power Source: US: 120V/12A/60Hz,
Europe/Asia: 220-240V/8A/50,60 Hz Taiwan: 110 V/12A/60Hz
Maximum Power
1.5 kVA
Consumption:
1-4
24 February, 1999 SPECIFICATIONS
Dimensions (without Platen Cover):
Width Depth Height
A258
A259
A260
Height: 1,018 mm with optional paper tray unit
620 mm
24.4"
620 mm
24.4"
620 mm
24.4"
680 mm
26.8"
757 mm
29.8"
757 mm
29.8"
602 mm
23.7"
602 mm
23.7"
602 mm
23.7"
Weight: Manual Duplex: 105 kg (231.3 lbs.)
Auto Duplex: 108 kg (237.9 lbs.)
Optional Equipment: Automatic Document Feeder (ARDF): A663
Sorter Stapler: A555 (10 bins), A834 (20 bins), Sorter: A849 (3 bins) Film Projector: A846 Holder for Film Projector Unit: A702-19 Paper Tray Unit: A832 (2 trays), A833 (3 trays) Key Counter Platen Cover: A749-00 Original Tray: A430-07 (Type F)
Overall
Information
1-5
SPECIFICATIONS 24 February, 1999

1.1.3 PLATEN/ARDF ORIGINAL SIZE DETECTION

Size (width x length)
[mm]
A3 (297 x 420) L No Yes No Yes B4 (257 x 364) L No Yes No Yes A4 (210 x 297) L No Yes Yes Yes A4 (297 x 210) S No Yes Yes Yes B5 (182 x 257) L No Yes No Yes B5 (257 x 182) S No Yes No Yes A5 (148 x 210) L No No* No Yes A5 (210 x 148) S No No No Yes B6 (128 x 182) L No No No Yes B6 (182 x 128) S No No No Yes 11" x 17" (DLT) Yes No Yes Yes 11" x 15" No No Yes No 10" x 14" No No Yes Yes
8.5" x 14" (LG) Yes No Yes No
8.5" x 13" (F4) No No Yes Yes
8.25" x 13" No No No No 8" x 13"(F) No Yes Yes No
8.5" x 11" (LT) Yes No Yes Yes 11" x 8.5" (LT) Yes No Yes Yes 8" x 10.5" No No No No 8" x 10" No No Yes No
5.5" x 8.5" (HLT) No* No Yes No
8.5" x 5.5" (HLT) No No Yes No A6 (105 x 148) L No No No No
Inches Metric Inches Metric
Platen ARDF
*: For A5 lengthwise/HLT, SP4-303 can be used to select “Cannot detect
original size” or “A5 lengthwise/5.5" x 8.5"(HLT)”.
1-6
24 February, 1999 SPECIFICATIONS

1.1.4 COPY PAPER SIZE

Optional
S.Stapler
Size
(width x length)
[mm]
Trays in the main body Bypass
Paper Tray (A258)
Duplex Tray (A259/A260)
Inches Metric Inches Metric
All
versions
(A258/
259/260)
A3 (297 x 420) L No Yes Yes Yes Yes Yes B4 (257 x 364) L No Yes Yes Yes Yes Yes A4 (210 x 297) L Yes Yes Yes Yes Yes Yes A4 (297 x 210) S Yes Yes Yes Yes Yes Yes B5 (182 x 257) L No Yes No Yes Yes Yes B5 (257 x 182) S No Yes No Yes Yes Yes A5 (148 x 210) L No Yes No No Yes Yes (1) A5 (210 x 148) S No No Yes Yes Yes Yes (2) B6 (128 x 182) L No No No No Yes Yes (1) B6 (182 x 128) S No No No No No No 12” x 18” No No No No Yes Yes (3) 11" x 17" (DLT) Yes Yes Yes Yes Yes Yes 11" x 15" Yes No Yes No Yes Yes 10" x 14" Yes No Yes No Yes Yes
8.5" x 14" (LG) Yes No Yes No Yes Yes
8.5" x 13" (F4) Yes Yes Yes Yes Yes Yes
8.25" x 13" No No Yes Yes Yes Yes 8" x 13"(F) No No Yes Yes Yes Yes
8.5" x 11" (LT) Yes Yes Yes Yes Yes Yes 11" x 8.5" (LT) Yes Yes Yes Yes Yes Yes 8" x 10.5" No No Yes No Yes Yes 8" x 10" Yes No Yes Yes Yes Yes
5.5" x 8.5" (HLT) No No No No Yes Yes (1)
8.5" x 5.5" (HLT) Yes No Yes Yes Yes Yes ( 2) A6 (105 x 148) L No No No No Yes Yes (2)
Overall
Information
Yes (1): Stapling is not allowed. Yes (2): Using the proof tray only. Sorter bins cannot be used.
Yes (3): 20-bin sorter (A834): Stapling is not allowed.
10-bin sorter (A555): Not available
1-7
SPECIFICATIONS 24 February, 1999

1.1.5 APS PAPER SIZES AVAILABLE

— For metric machines —
200
173
163
141
122
115
100
93
87
82
75
71
65
61
57
50
~
51
A3
B4
A4L B5L
A5L A4S
B5S
A5S
8.5
x 11
11
x 8.5
8.5
x 13
11
x 15
~
~
~
~
~
~
~
~
~
~
~
~
~
174
164
142
123
116
101
94
88
83
76
72
66
——————A3—B4——A4L —————A3B4——A4L ———A3B4—A4L
——A3B4—A4LB5L——A5L——————
A3B4—A4LB5L—A5L—————————
——————
S
A4SB5
————— ——— — — — — ————A3— —
A4SB5
8.5
B5L——A5L————
x13
A4
S S
A5
S
8.5
x11
11
x8.5
8.5
x13
11
x15
B5
S
—— ————————— — — — — ——A4LB5L————A5L —
8.5
B5L A5L
x13
——
A5
S
A5
S
——————
~
62
58
8.5 B5L A5L
x13
————
~
: Not allowed in platen cover mode. L: Lengthwise S: Sideways
— For standard machines (in inches)—
11x17 11x15
8.5x14
8.5x11
5.5
x8.5
8.5
x5.5
11x8.5
8x10
10x14
8x13
200
~
177
—————11x1711x1711x15 — 11x15 11x15 — ———— — 11x17
11
x17
———
————— — 11x17 10x14 8x10 — —————10x14— ———11x17—8x13————
176
~
156
11
x15
155
~
130
8.5
x14
129
~
122
8.5
x11
11
x8.5
121
~
101
11
x17
100
~
94
8.5
x14
8.5
x11
5.5
x8.5
8.5
x5.5
11
x8.5
93
~
86
—— ————
——————
——————
————
85
~
78
8.5 x14
77
~
75
8.5
x14
8.5
x14
8.5
x11
8.5
x11
74
~
66
8.5
x11
——
——
65
~
51
8.5 x11
5.5
x8.5
8.5
x5.5
5.5
x8.5
5.5
x8.5
50
~
5.5
x8.5
5.5
x8.5
5.5
x8.5
— —
5.5
x14
: Not allowed in platen cover mode.
1-8
24 February, 1999 SPECIFICATIONS
NOTE:
1) The tables indicate the copy paper size for each original for 50 to 200 % zoom ratios.
2) After specifying a zoom ratio, APS automatically selects a paper size that guarantees the quality of the magnified copy image, if there is a paper size available for the equivalent standard reproduction ratio.
3) If there is no paper that corresponds to the detected size, the machine displays the message "Set xx paper in tray" and stops the job (copying is still possible).
4) For "—" in the above tables, the machine displays the message "Cannot detect original size" and stops the job (copying is still po ssible). The selected paper feed tray does not change.
5) When less than 49% or more than 201% is selected, APS behaves in accordance with note 4 above.
6) APS also supports the by-pass feed table (except for non-standard paper sizes). When the paper size selected by APS can only be fed from the by-pass feed table, the machine displays a warning to instruct the user to use the by-pass feed table.
7) APS does not support A6, B6, and A5.
Overall
Information

1.1.6 NOISE EMISSION

Sound pressure level
The measurements were made in accordance with ISO 7779 at the operator positions.
Copier only Full system*
Less than 38.5 dB (A) Less than 55 dB (A)
*: Full system: Copier with document feeder, 500 sheets x 3 trays unit, FPU,
and a sorter stapler.
Sound power level
The measurements were made in accordance with ISO 7779.
Copier only Full system*
Stand-by Less than 55 dB (A) Less than 59 dB (A)
Copying
(This value is for the
black copy mode.)
*: Full system: Copier with document feeder, 500 sheets x 3 trays unit, FPU,
and a sorter stapler.
Less than 68 dB (A) Less than 72 dB (A)
1-9
SPECIFICATIONS 24 February, 1999

1.1.7 POWER CONSUMPTION

(1) Maximum power cons umption
1.5 kVA
(2) Average power consumption
A258/A259/A260 Copiers
Standby
Warm-up
Copying
Energy Saver Mode
0.4 kW
1.3 kW
1.1 kW (B/W A4 å)
0.6 kW (full color A4 å) Value for standby minus 25 W

1.1.8 DISPLAY EDITOR SPECIFICATIONS

Scanned image
Displayed image
Area specification procedure
The copier's scanner scans the image.
Maximum A3/DLT (11" x 17"): Redu ced image display
144 x 192 mm, 256 colors (8 bits/dot)
640 x 480 dots, 0.33 mm/dot
Reduces the dpi of scanned images to approximately 25 dpi and displays the entire image
Zoom display: 4 levels (200%, 264%, 400%, 528%)
Move the arrow on the screen by using the cursor key
and enter a point by pressing the coordinate entry key.
1-10
24 February, 1999 MECHANISM OVERVIEW

1.2 MECHANISM OVERVIEW

1.2.1 IMAGE GENERATION PROCESS

Overall
Information
10
11
9
12
1
2
3
4
5
8
A259V110.WMF
67
1-11
MECHANISM OVERVIEW 24 February, 1999
(1) Drum charge
The charge corona applies a negative charge to the OPC drum and the grid ensures that this charge is even.
(2) Quenching
After cleaning, the OPC is fully exposed to light from an array of red LEDs, quenching the residual charge on the OPC drum in preparation for the next copy cycle.
(3) Drum Cleaning
The cleaning brush increases drum cleaning efficiency by applying lubricant to the OPC drum. The cleaning blade scrapes the residual toner off the OPC drum.
(4) PCC (Pre-cleaning corona)
The PCC discharges the photoconductor drum and applies AC and negative DC to reduce the charge holding the residual toner to the drum, thereby improving the efficacy of the cleaning brush.
(5) Belt transfer
Positive charge applied to the back of the transfer belt transfers the toner image on the OPC drum to the transfer belt.
(6) Paper transfer
The negatively charged toner image is transferred to the paper by giving a positive charge to the back of the paper while the paper and transfer belt are held in close contact.
(7) Paper separation corona
After transfer, the separation corona quenches the negative charge on the paper to reduce the attraction between the belt and paper. The curvature of the belt causes the paper to separate from the transfer belt.
(8) Belt cleaning unit and lubricant application brush
The brush applies lubricant, which makes it easier for the counter blade to scrape excess toner off the transfer belt.
1-12
24 February, 1999 MECHANISM OVERVIEW
(9) ID sensor
The ID sensor detects the density of the sensor patches developed on the OPC drum. The signal from the ID sensor is used for process control and toner supply control.
(10) Development
The latent image on the drum attracts the negatively charged toner. Toner is preferentially attracted to those places on the drum surface where the laser reduced the negative charge. The development units for each color are included in the revolver unit.
(11) Potential sensor
The potential sensor detects the electrical potential (the strength of the electric field) on the photoconductor dru m for process contr ol.
(12) Laser exposure
The polygon mirror reflects the laser beam emitted from the laser diode and projects it onto the drum through the f-theta lens, drum mirror, and toner shield glass. The laser output varies in intensity to correspond to the image data, and this forms a latent image on the drum.
Overall
Information
1-13
MAJOR UNIT LAYOUT AND PAPER FEED PATH 24 February, 1999

1.3 MAJOR UNIT LAYOUT AND PAPER FEED PATH

1
2
3
8
7
4
6
1-14
5
A259V109.WMF
24 February, 1999 MAJOR UNIT LAYOUT AND PAPER FEED PATH
(1) Scanner
1. 400 dpi, 10-bit scanning in both main and sub-scan directions
2. 3-line CCD
3. Halogen exposure lamp
4. 5-phase stepper motor drive
5. Dual-side continuous scan (A4) support (in continuous copy mode)
(2) Operation panel (A259, A260)
1. 10.4-inch (640 x 480) color LCD (8-bit) touch-panel
2. An additional operation panel is installed when the printer controller is installed.
(3) Laser unit
1. Optics: 6-sided polygon mirror + 2 f-theta lenses + BTL
2. Polygon mirror motor (16535 rpm) with ball bearing
3. 400 dpi (8 bits per pixel for each color) in copy mode 600 dpi (8 bits per pixel for each color) in printer mode
4. Modulation: PM + PWM
Overall
Information
(4) Transfer belt
1. Transfer belt: Always in contact with the drum
2. Belt transfer: Indirect application of voltage with a roller
3. Paper transfer: Roller transfer
4. Registration: Synchronization by the transfer belt H.P. sensor
5. Drive: Synchronized with the drum (same motor)
6. Separation: Curvature separation + corona unit
7. Transfer cycle: 1 belt rotation/A4, 2 rotations/A3
8. Belt cleaning: Counter blade
9. Lubrication: Brush roller with lubricant bar
1-15
MAJOR UNIT LAYOUT AND PAPER FEED PATH 24 February, 1999
(5) Paper feed/transport system
1. Paper feed (A258)
Front loading 500 sheets, 1-layer tray + by-pass feed
2. Transport: Transport belt + fan
3. Duplexing: Duplex unit installed as a standard component (A259/A260 only)
4. Paper tray (optional): Holds 500 sheets x 2 trays or 500 sheets x 3 trays.
(6) Fusing and paper exit
1. Fusing: Silicone roller fusing
2. Oil application method: Do uble roller system
3. Cleaning: Cleaning rollers (for hot and pressure rollers)
Europe/Asia:
Cleaning roller for hot roller, cleaning blade for pressure roller
4. OHP/thick paper speed change
(7) Development and toner supply
1. Development: Two-component magnetic brush development
2. Development switching: Revolver system
3. Image density control: ID sensor + process control
4. Toner supply: Screw-in bottle (220 g)
5. Toner supply unit: Front of developer unit (rotation type)
(8) Drum unit
1. The drum unit contains the photoconductor drum, charge corona unit, and cleaning unit.
2. Charge corona unit: Single-wire scorotron
3. Quenching lamp: LED array
4. Drive: Synchronized with the transfer belt (DC brushless motor + flywheel)
5. Potential sensor included
1-16
24 February, 1999 PARTS LAYOUT

1.4 PARTS LAYOUT

1.4.1 MECHANICAL COMPONENT LAYOUT

5 6 7 8 9 11 13 14
1210
Overall
Information
4
3
2
1
1. Paper Tray (A258)/Duplex Tray (A259/A260)
2. Pressure Roller
3. Hot Roller
4. 2nd Scanner
5. Revolver Development Unit
6. 1st Scanner
7. Drum Mirror
8. Toner Shield Glass
9. BTL (Barrel Torroidal Lens)
10. Charge Corona Unit
11. Scanner Lens
12. 2nd F-theta Lens
15
16
17 18
19 20 21
A259V108.WMF
22232425
14. 1st F-theta Lens
15. Polygon Mirror
16. Drum Cleaning Unit
17. OPC Drum
18. Transfer Belt
19. By-pass Feed Table
20. Transfer Belt Unit
21. Registration Roller
22. Transfer Belt Bias Roller
23. Paper Transfer Unit
24. Belt Cleaning Unit
25. Transport Belt
13. CCD Board
1-17
PARTS LAYOUT 24 February, 1999

1.4.2 ELECTRICAL COMPONENT LAYOUT

20
19
18
17
16
21
15
22
1
2
3
4
5
6
7
23
8
9
10
11
12
13
A259V101.WMF
14
1. Scanner Motor Drive Board
2. Scanner Motor
3. Platen Cover Position Sensor
4. IDU Board
5. Original Length Sensor
6. Lamp Regulator
7. Scanner Exhaust Fan
8. CCD Board (SBU)
9. Scanner IPU Board
10. Main Control Board
11. LD (Laser Diode) Main Control Board
Diagram 1
12. Laser Synchronizing Detector Board 2
13. Polygon Motor Drive Board
14. Polygon Motor
15. LD (Laser Diode) Drive Board
16. Laser Synchronizing Detector Board 1
17. Optics Anti-condensation Heater
18. Original Width Sensor
19. Exposure Lamp
20. Optics Cooling Fan
21. Scanner H.P. Sensor
22. Thermostat
23. Original Length Sensor-Sub
1-18
24 February, 1999 PARTS LAYOUT
14
13
12
2
1
3
Overall
Information
4
5
6
7
11
A259V102.WMF
10
9
8
Diagram 2
1. Main Power Switch
2. Belt Cleaning H.P. Sensor
3. Paper Tray Detector Switch
4. Transfer Belt Home Position Sensor
5. Transfer Belt Heater
6. Paper Height Sensor-1
7. Paper Height Sensor-2
8. Paper Transfer H.P. Sensor
9. Paper Transfer Unit Heater
10. Counters
11. Transport Fan
12. Front Door Switch
13. Paper Exit Door Switch (A259/A260 only)
14. Junction Gate Solenoid (A259/A260 only)
1-19
PARTS LAYOUT 24 February, 1999
1
2
3
4
16
15
14
13
12
1. Paper Transfer Positioning Clutch
2. Paper Feed Motor
3. Registration Clutch
5
6
7
8
9
10
A259V103.WMF
11
Diagram 3
9. By-pass Pick-up Solenoid
10. Upper Limit Sensor
11. Paper End Sensor
4. Relay Clutch
5. By-pass Feed Clutch
6. Paper Feed Clutch
7. By-pass Paper Width Detection Board
8. Vertical Transport Switch
12. Relay Sensor
13. By-pass Paper End Sensor
14. By-pass Feed Table Switch
15. Registration Sensor
16. Temperature and Humidity Sensor
1-20
24 February, 1999 PARTS LAYOUT
10
9
1
8
7
6
Overall
Information
5
4
3
19
18
17
16
15
1. Operation Panel
2. Paper Separation Corona Unit
2
11
12
13
A259V104.WMF
14
Diagram 4
10. Pressure Roller Thermistor
11. Duplex Entrance Sensor
3. Pressure Roller Thermofuse
4. Pressure Roller Fusing Lamp
5. Paper Exit Sensor
6. Oil End Sensor
7. Hot Roller Thermistor
8. Hot Roller Fusing Lamp
9. Hot Roller Thermofuse
12. Duplex Turn Sensor
13. Duplex Paper End Sensor
14. Duplex Feed Motor
15. Side Fence Jogger HP Sensor
16. Duplex Side Fence Jogger Motor
17. Duplex End Fence Jogger Motor
18. Duplex Control Board
19. End Fence Jogger HP Sensor
1-21
PARTS LAYOUT 24 February, 1999
1
10
2
9
8
7
6
5
1. Charge Corona Unit
2. Quenching Lamp
3. PCC (Pre-cleaning Corona)
4. ID Sensor
5. Charge Corona Fan
3
A259V105.WMF
4
Diagram 5
6. Toner Cartridge Sensor
7. Revolver H.P. Sensor
8. Toner End Sensor
9. High Voltage Supply Board: B
10. Potential Sensor
1-22
24 February, 1999 PARTS LAYOUT
2
1
3
Overall
Information
4
5
6
9
A259V106.WMF
1. Development Clutch
2. Toner Supply Motor
3. Revolver Motor
4. Belt Lubricant Clutch
5. Fusing Motor
8
7
Diagram 6
6. Fusing Clutch
7. Belt Cleaning Clutch
8. Tray Lift Motor
9. Drum Motor
1-23
PARTS LAYOUT 24 February, 1999
1
2
12
11
10
9
8
7
Diagram 7
1. High Voltage Supply Board: C, G
2. Rear Cooling Fan
3. Fusing Unit Fan
4. PSU (Power Supply Unit)
5. High Voltage Supply Board: T2, D
6. CSS/Bank Interface Board
3
4
A259V107.WMF
56
7. Revolver Motor Drive Board
8. Used Toner Sensor
9. High Voltage Supply Board: T1, PCC
10. Main Exhaust Fan
11. I/O (Input/Output) Control Board
12. PSU Fan
1-24
24 February, 1999 PARTS LAYOUT

1.4.3 DRIVE LAYOUT

5
1
Overall
Information
2
3
4
A259V111.WMF
Five motors drive the mechanical components for this machine. The drive sections driven by these five motors are listed below.
1. Scanner Drive
2. Development/Drum/Transfer Belt Drive
3. Paper Feed/Registration/Paper Transfer/Transport Belt Drive
4. Fusing Unit/Paper Exit Drive
5. Revolver Drive
1-25
PARTS LAYOUT 24 February, 1999

1.4.4 AIR FLOW

1
2
3
4
8
5
A259V112.WMF
1. Optics Cooling Fan
2. Fusing Unit Fan
3. Rear Cooling Fan
4. Scanner Exhaust Fan
5. Main Exhaust Fan
6. Transport Fan
7. Charge Corona Fan
8. PSU Fan
67
1-26
24 February, 1999 PARTS LAYOUT

1.4.5 ELECTRICAL COMPONENT DESCRIPTIONS

Printed Circuit Boards
Symbol Name Function Index-No Location
PCB 2
PCB 5
PCB3 PCB1 PSU Supplies AC and DC power. 7-4 K4
PCB4
PCB11 Main control board Controls the printer sequence. 1-10 J12
PCB6
PCB17
PCB16 LD drive board Drives the las er diode. 1-15 O17
PCB12
PCB13
PCB21 IDU Analyzes images for anti-counterfeiting. 1-4 M14 PCB18
PCB9
PC8
PCB10
PCB7 PCB19 Operation panel board Used to operate the copier. 4-1 H19 PCB22
PCB14
PCB15
PCB20
PCB23
Lamp regulator Supplies AC power to the exposure
lamp.
Scanner motor drive board
SBU Converts the light reflected from the
Scanner IPU board
I/O control board Interfaces the sensors, clutches,
LD main control board Controls the laser power, main scan
Laser synchronizing detector board 1
Laser synchronizing detector board 2
By-pass paper width detection board
High voltage supply board: T2, D
High voltage supply board: T1, PCC
High voltage supply board: B
High voltage supply board: C, G
Polygon mirror motor drive board
Revolver motor drive board
Interface board: CSS/Bank
Duplex control board Controls the duplex unit.
Temperature and humidity sensor board
Supplies DC power to the scanner motor.
original into video signals.
Converts the RGB image signal from the CCD to a KCMY signal and sends it to the LD main control board.
solenoids, and motors in the printer module with the main control board.
synchronizing sensors, and process control gamma correction.
Detects laser main scan synchronization while the latent image is being written to the drum.
Detects laser main scan synchronization while the latent image is being written to the drum.
Detects the paper width on the by-pass feed table.
Supplies power to the paper transfer bias roller and paper separation corona unit.
Supplies power to the transfer belt and pre-cleaning corona unit.
Supplies power to the development rollers.
Supplies power to the charge corona wire and grid.
Controls the polygon mirror motor.
Controls the revolver motor.
Connects to the CSS unit and optional paper tray unit.
Detects the ambient temperature and humidity.
1-6 O7
1-1 M7
1-8 J9
1-9 L8
7-11 D14
1-11 M16
1-16 O15
1-12 O15
3-7 A10
7-5 A1
7-9 A2
5-9 A3
7-1 A14
1-13 O15
7-7 F5
7-6 J9
F20
4-18
3-16 E19
(A259/A260
copiers only)
Overall
Information
1-27
PARTS LAYOUT 24 February, 1999
Motors
Symbol Name Function Index-No Remarks
M1 Scanner motor Drives the scanner. 1-2 M6 M2 Polygon mirror motor Drives the polygon mirror (laser unit). 1-14 O15
M11 Fusing motor Drives the transport and fusing units. 6-5 E8
M7 Paper feed motor Drives the paper feed unit. 3-2 A12
Tray lift motor Lifts the tray bottom plate.
M8
Drum motor
M10
M9 Toner supply motor Supplies toner. 6-2 A7 M3 Revolver drive motor Rotates the revolver unit. 6-3 G5
Duplex Side fence
M5
M6
M4
jogger motor Duplex End fence
jogger motor Duplex feed motor Drives the paper feed roller in the
Drives the drum, the development unit currently at the development position, and the transfer belt.
Drives the duplex unit side fences.
Drives the duplex unit end fences.
duplex unit.
6-8
6-9 A19
4-16
4-17
4-14
A12
(A258
models only)
G21
(A259/A260
copiers only)
G21
(A259/A260
copiers only)
G20
(A259/A260
copiers only)
Fan Motors
Symbol Name Function Index-No Remarks
FM4 Scanner exhaust fan Cools the scanner unit. 1-7 P7 FM2 Optics cooling fan Cools the scanner unit 1-20 O14 FM3 Charge corona fan Cools the charge corona unit. 5-5 A6
FM6 FM1 Transport fan Attracts copy paper to the transport belt. 2-11 A11
FM5 Fusing unit fan Cools the fusing unit. 7-3 E1 FM7 Rear cooling unit fan Cools the rear section of the copier. 7-2 E10 FM8 PSU fan Cools the PSU. 7-12 A7
Main exhaust fan
Sucks air from the charge and transfer areas out of the machine.
7-10 A17
1-28
24 February, 1999 PARTS LAYOUT
Sensors
Symbol Name Function Index-No Remarks
S21
Platen cover position
sensor S23 Scanner H.P. sensor Detects the scanner home position. 1-21 P14 S20 Original length sensor Detects the length of the original. 1-5 N7 S24 Original width sensor Detects the width of the original. 1-18 P14
S16
Transfer belt H.P.
sensor S18 Paper exit sensor Detects paper jams at the paper exit. 4-5 F1
S2
Toner cartridge sensor Detects the presence or absence of
S1 Toner end sensor Detects the presence or absence of
S4
Potential sensor Detects the potential of the drum
ID sensor Detects the density of toner on the
S5
S3
S17
Revolver H.P. sensor Detects if the revolver is at the home
Registration H.P.
sensor
Relay sensor
S9
S12 Used toner sensor Detects if the used toner tank is full 7-8 A15
S6
S13
S7
Belt cleani ng H.P.
sensor
Paper transfer H.P.
sensor
By-pass feed paper
end sensor
Upper limit sensor Detects the upper limit position of the
S8
Paper height sensor 2 Detects the amount of paper in the S15
Paper height sensor 1 S14
Tray paper end sensor S10
Side fence jogger HP S25
sensor
End fence jogger HP S26
sensor
Duplex paper end S27
sensor
Detects if the platen cover is opened or closed.
Detects the mark on the transfer belt.
toner cartridges. toner in a cartridge. surface. developed ID sensor patch on the
drum. position.
Detects paper jams at the registration section.
Detects paper jams at the relay section.
Detects if the belt cleaning unit is at the home position.
Detects if the paper transfer unit is at the home position.
Detects if there is paper on the by-pass feed table.
tray bottom plate.
tray. Detects the amount of paper in the
tray. Detects if there is paper in the paper
feed tray. Detects the home position of the
duplex unit side fence. Detects the home position of the
duplex unit end fence. Detects if there is paper in the duplex
unit.
1-3 O7
2-4 A18
5-6 A4 5-8 A4
5-10 A5
5-4 A5
5-7 A4
3-15 A19
A13
3-12
(A258
models only)
2-2 A8 2-8 A15
3-13 A8
A13
3-10
(A258
models only)
A16
2-7
(A258
models only)
A16
2-6
(A258
models only)
G13
3-11
(A258
models only)
G22
4-15
(A259/A260
models only)
G22
4-19
(A259/A260
models only)
G22
4-13
(A259/A260
models only)
Overall
Information
1-29
PARTS LAYOUT 24 February, 1999
Symbol Name Function Index-No Remarks
S28
S29
S19 S22
S11
Duplex entrance
sensor
Duplex turn sensor Detects when copy paper is being
Oil end sensor Detects if there is silicone oil in that
Original length sensor -
sub
Relay Sensor Detects a paper jam at the relay
Detects when copy pa per comes into the duplex unit.
reversed in the duplex unit.
tank. Detects the length of the original
section
G23
4-11
(A259/A260
models only)
G23
4-12
(A259/A260
models only)
4-6 G1
1-23 P7
A14
3-12
(A259/A260
models only)
Switches
Symbols Name Function Index-No Remarks
SW1 Main power switch Turns the power to the copier on or off. 2-1 M1
Front door switch Cuts the DC line to the high voltage
SW2
SW3
SW4
SW5
SW6
Paper exit door switch Detects if the paper exit door is open or
By-pass feed table switch
Paper tray detector switch
Vertical transport switch
supply board when the front door is open.
closed. Detects if the by-pass feed table is open
or closed. Detects the presence or absence of a
paper tray. Detects if the vertical transport door is
open or closed.
2-12 E11
A7
2-13
(A259/A260
models only)
3-14 A8
A16
2-3
(A258
models only)
3-8 A17
Clutches
Symbols Name Function Index-No Remarks
CL1
CL3
By-pass feed clutch
Registration clutch Transmits drive to the registration
CL6 Relay clutch Transmits drive to the relay rollers. 3-4 A18 CL2
Paper feed clutch
CL8 Fusing clutch Transmits drive to the fusing unit. 6-6 E1 CL9
Belt lubricant clutch Transmits drive to the belt lubricant
CL7 Belt cleaning clutch Transmits drive to the belt cleaning unit. 6-7 E2 CL5
CL4
Development clutch Transmits drive to the development
Paper transfer positioning clutch
Transmits drive to the by-pass feed mechanism.
rollers.
Transmits drive to the paper feed mechanism.
mechanism.
mechanism. Transmits drive to the paper transfer
unit.
1-30
3-5 A9
3-3 A18
3-6 A17
6-4 E2
6-1 E3
3-1 A11
24 February, 1999 PARTS LAYOUT
Solenoids
Symbols Name Function Index-No Remarks
SOL1
SOL2
By-pass pickup solenoid
Junction gate solenoid Raises the junction gate for the duplex
Lowers the by-pass pick-up roller.
tray.
3-9 A9
2-14
(A259/A260
copiers only)
A7
Lamps
Symbol Name Function Index-No Remarks
L1 Hot roller fusing lamp Provides heat to the hot roller. 4-7 H1
Pressure roller fusing
L2
lamp Exposure lamp Applies high intensity light to the original
L3
Quenching lamp
L4
Provides heat to the pressure roller.
for exposure. Neutralizes any charge remaining on the
photoconductor.
4-4 G1
1-19 O5
5-2 A6
Overall
Information
Heaters
Symbol Name Function Index-No Remarks
H3
H1
H2
Optics anti­condensation heater
Paper transfer unit heater
Transfer belt heater
Prevents moisture from forming on the optics.
Prevents moisture from forming around the paper transfer unit.
Used to stabilize the temperature around the transfer belt.
1-17 L1
2-9 J1
2-5 K1
Thermistors
Symbol Name Function Index-No Remarks
TH2
TH1
Hot roller thermistor Controls the temperature of the hot
roller.
Pressure roller thermistor
Controls the temperature of the pressure roller.
4-6 G1
4-9 F1
Thermofuses
Symbol Name Function Index-No Remarks
TF1 Hot roller thermofuse Protects the hot roller from overheating. 4-8 H1 TF2
Pressure roller thermofuse
Protects the pressure roller from overheating.
4-3 H1
Thermostat
Symbol Name Function Index-No Remarks
TS1
Thermostat Prevents the exposure lam p from
overheating when it is on for a long time.
1-31
1-22 O6
PARTS LAYOUT 24 February, 1999
Counter
Symbol Name Function Index-No Remarks
CO1
CO2
Upper mechanical counter
Lower mechanical counter
Indicates the total number of development cycles made using the C, M, and Y development units;
Shows the total number of black developments.
2-10 A9
2-10 A10
1-32
24 February, 1999 PROCESS CONTROL

2. DETAILED DESCRIPTIONS

2.1 PROCESS CONTROL

2.1.1 OVERVIEW

This copier provides the following forms of process control:
Potential control (done every process control self check)
Process control gamma calibration (done every process control self check,
after potential control)
Toner supply control (done every copy)
The components used for process control are:
Potential sensor (a new type of sensor is used, known as a ‘feedback
measurement potential sensor’). This sensor detects the surface potential of the drum.
ID sensor (a new type of sensor is used, known as a ‘diffused reflection ID
sensor‘). The ID sensor detects the amount of toner on the drum.
Detailed
Descriptions
Revolver
LD
V
B
Drum
ID sensor
Potential
sensor
Pixel
counting
V
G
Fuzzy logic
Toner supply
calculation
Motor rotation time
Process control
γ
Development
characteristics
Development
potential calculation
Pointer table
V
D
LD main
ASIC
VBV
L
Toner supply motor
2-1
VGVBI
A259A001.WMF
LD
PROCESS CONTROL 24 February, 1999

2.1.2 POTENTIAL CONTROL

Overview
Potential control is the process of controlling the development potential to maintain the density of the toner image on the drum. It does this by compensating for variations in drum chargeability and toner chargeability.
The machine uses the image density (ID) sensor to measure drum reflectivity and the density of a standard sensor pattern. It uses the potential sensor to detect the potential on the standard sensor pattern (before the pattern is developed). These tests are done during the process control self check, which is done at specific times (such as after replacing the developer).
The ID and potential sensor outputs are used to calculate the development potential. This is the difference between the development bias voltage and the voltage of areas of the drum that have been discharged by laser exposure at full power. If changes in this potential are not accounted for, the color balance will be poor.
Depending on the development potential that is calculated, the machine uses a look-up table in memory (called a pointer table) to adjust the following:
VD: Drum potential without exposure - to adjust this, the machine adjusts the
charge corona grid voltage (V
: Drum potential with the strongest exposure - to adjust this, the machine
V
L
G)
adjusts the laser diode input current (ILD)
VB: Development bias
Potential control controls the development potential so that the maximum amount of toner applied to the drum is kept constant. However, the medium (greyscale) range is ignored. To improve this situation, a new process called ‘process control gamma correction’ is done after potenti al contr ol. Thi s pr ocess de fin es LD output for all 256 grades of the greyscale (development bias and charge corona grid potential are not affected).
Potential Control Timing
The machine carries out potential control and process control gamma correction during the ‘process control self check’. There are five types of process control self check, categorized according to their execution times. Process control takes approximately 3 minutes.
(1) Forced process control
After replacing the drum, the technician must do the forced process control procedure (SP3-126). There is no need to use SP3-126 at installation, because forced process control is included in the developer initialization process (SP2-225). (See 6.6.3 Developer Collection Procedure for details.)
2-2
24 February, 1999 PROCESS CONTROL
(2) Initial process control self check
The initial process control starts automatically when the power is turned on (or when the machine returns to standby mode from sleep mode), but only if the hot roller in the fusing unit is less than 100 degrees centigrade. This process control is done only when SP3-125 (Set Potential Control Method) is set to "0 (Auto)."
(3) Interval process control self check
The interval process control starts automatically at the end of a copy job during which the total number of copies exceeds a preset value.
The preset value can be defined using SP3-973 (Set Process Control Self Check Interval). The factory setting is 150 sheets. The maximum possible interval is 500 sheets. Using a shorter interval reduces the machine’s average copying speed. Setting the process control interval to 0 disables the interval process control.
(4) Timed process control self check
The timer is reset to 6 hours after a process control self check, at the end of a copy job, when the power is switched on, after toner end recovery, or if the front door is opened and closed.
The 6-hour interval can be adjusted with SP 3-972.
(5) ACC-Run-Time Process Control Self Check
A process control self check that is active before the execution of ACC (auto color calibration). The checks is identical to the interval process control self check.
Detailed
Descriptions
2-3
PROCESS CONTROL 24 February, 1999

2.1.3 PROCESS CONTROL SELF CHECK

Flow Chart
Start
VSG Adjustment (ID sensor)
ID sensor pattern generation
Sensor pattern potential
detection
Sensor pattern density
detection
Toner amount calculation
Development potential
calculation
VD, VB, VL selection
Process control gamma
correction
Step (1)
Step (2)
Step (3)
Step (4)
Step (5)
Step (6)
Step (7)
End
A259A002.WMF
2-4
24 February, 1999 PROCESS CONTROL


 

Step 1: VSG Adjustment
The type of ID sensor used in this machine responds differently for black and color, so there are two V
The type of ID sensor used in this machine is very sensitive, and outputs some voltage even if there is no light being reflected off the drum. This output is known as the ‘offset’. It is about 1 V for black and about 0.2 V for color, but is different for each sensor. For more details on this sensor (known as a ‘diffused reflection ID sensor’), see ‘Step 4: Sensor Pattern Density Detection’.
The ID sensor checks the bare drum’s reflectivity and the machine calibrates the output of the ID sensor as follows. This voltage is known as VSG:
Black: (1.8 + offset) ± 0.1V
Color: Must be between 0.2 and 3 V
This calibration compensates for the drum’s condition (due to ageing) and the ID sensor condition, such as dirt on the surface of the drum or ID sensor.
Note that VSG for black is less than half that in previous models. This is due to the new type of ID sensor.
values, one for black toner and one for CMY toner.
SG
Detailed
Descriptions
Step 2: ID Sensor Pattern Generation
The machine makes a 16-grade pattern on the drum for each toner color. Each grade is made by changing the LD power. At this stage, the patterns are not developed; they remain as latent images.
1st level of LD power
2nd level of LD power
3rd level of LD power
15th level of LD power
16th level of LD power
20
25
20



 
A259A004.WMF
2-5
PROCESS CONTROL 24 February, 1999
Step 3: Sensor Pattern Potential Detection
Process
The potential sensor detects the potential on each grade of the 16-grade sensor pattern latent image, for each colour, and the output is stored in memory.
Feedback Type Potential Sensor
d
[B]
[A]
V
Feedback circuit
dc
A259A003.WMF
This copier uses a feedback potential sensor. A description of the principles of feedback potential sensors follows.
The detector [A] detects the strength of electric fields emitted from the drum surface, which depend on the surface potential of the drum. The feedback circuit applies voltage to the probe [B] until the electric field strength is offset at the detector. The level of this voltage determines the magnitude of the surface potential on the drum surface and is presented as output.
The major features of this measurement method are:
Even if the distance [d] between the drum (1) and the potential sensor (2)
fluctuates, the measurement of the drum surface potential is still accurate.
The potential sensor does not have to be calibrated before the process control
self check, so the calibration step required for previous models can be skipped.
Residual potential affected the calibration for the older type of sensor, so before
process control self checks, the machine had to wait 10 minutes in standby mode for the residual voltage to disappear. For this new sensor, calibration is not needed, so the influence of residual potential on the drum can be ignored.
2-6
24 February, 1999 PROCESS CONTROL
Step 4: Sensor Pattern Density Detection
Process
The development rollers of the respective colors develop the sensor pattern latent images for K, Y, C, and M generated in Step (2). In Step (4), the ID sensor detects the densities of the 16 patch patterns for each color. This data goes to memory.
Diffused Reflection ID Sensor
Drum
LED
Detector
A259A006.WMF
(Direct Reflection Type ID Sensor)
Toner
Diffuse Beam
Detector (Diffused Reflection Type ID Sensor)
A259A007.WMF
LED
Drum
Toner
Other Diffuse Beams
This copier uses a diffused reflection ID sensor. In addition to the ray directly reflected from the drum, there are diffuse beams reflected at all angles from the toner on the drum. This sensor detects image density by receiving some of these diffuse beams, not by receiving the beam directly reflected from the toner.
Using this type of sensor improves the measurement accuracy of the sensor pattern densities particularly for Y, C, and M toners. The following explains why.
Detailed
Descriptions
Color (Y, C, M) toners
SP
V
min
V
(1): Component of light reflected from the drum (2): Component of light reflected from C, M, or Y toner
Figure A
Relationship between the output of the normal reflection type ID sensor
A259A008.WMF
and the amount of toner on the drum for C, M, and Y toners
SP = (1) + (2)
V
(2)
(1)
M/A
2-7
PROCESS CONTROL 24 February, 1999
Figure B
output of the diffused reflection ID sensor and the amount of toner on the drum for C, M, and Y toners
Relationship between the
A259A009.WMF
Figure C
output of the diffused reflection ID sensor and the amount of toner on the drum for K toner
Relationship between the
A259A010.WMF
Figure A shows the relationship between the output of the normal reflection ID sensor and the amount of Y, C, or M toner attached to the drum. This shows that the ID sensor output (Vsp) results from not only the light reflected from the toner but also the component of light reflected from the drum.
With this old sensor type, the machine was unable to accurately detect high values of M/A for colored toner (i.e., to the right of the minimum in the VSP curve at Vmin.
The diffused reflection ID sensor, on the other hand, picks up little light that is reflected from the drum. So, the relationship between the diffused reflection ID sensor output and the amount of toner on the drum is linear, as shown in Figure B. This means that high densities of colored toner can be measured accurately.
K toner
The ID sensor output for K toner tends to decrease as the density of toner on the drum increases. Therefore, the relationship between the ID sensor output and the amount of K toner on the drum is as shown in Figure C.
Step 5: Toner Amount Calculation
The amount of toner on the drum (M/A, mass per unit area, mg/cm2) is calculated for each of the 16 grades of the sensor pattern from the ID sensor output value (Vsp) from each grade of the pattern.
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24 February, 1999 PROCESS CONTROL
Step 6: Development Potential Calculation
V
When the development potential is smaller
Amount of toner on the drum
V
D
V
B
V
L
A259A011.WMF
V
X
V
D
V
B
V
L
When the development potential is larger
X
The development potential (VDP) is the capability to attract toner to the drum and can be shown as: VB - V
: Development bias
V
B
VL: Drum potential after full laser exposure
L
See the above drawing for two examples. The machine calculates the approximate current development potential from the
sensor readings. This consists of the following steps:
1. The machine converts the gradation pattern densities (from the ID sensor) into an actual toner amount on the drum (M/A) for each grade of the pattern.
Detailed
Descriptions
2. From the potential and ID sensor outputs, the machine then determines the relationship between the drum potential and the amount of toner developed on the drum. This is known as the development gamma factor, or γMA.
3. The machine can now calculate the development potential (VDP) that would be required to obtain the ideal toner density (known as M/A max) on an area of the drum developed with full laser power, under the machine’s present conditions.
MAmax
MA
γ
Amount of toner
Vdp
Vk
Vkp
MAmax = 0.7 mg/cm2 for each color
Development potential
A259A012.WMF
2-9
PROCESS CONTROL 24 February, 1999
NOTE:
For Y, C, and M toners, the new type of ID sensor allows higher densities of toner to be measured accurately (refer to the descriptions in Step 4, Sensor Pattern Density Detection). This permits the calculation of γ M/A at a higher accuracy than a normal reflection ID sensor, because the measurements at higher densities (M/A values) are more reliable.
Step 7: Selecting the Optimum VD, VB, V
L
The machine now adjusts VD, VB, and VL to try to bring the development potential VDP to the ideal value. To do this, it uses a pointer table. This is a look-up table in ROM of VDP against VD, VB, and V
L.
The machine takes the value of VDP calculated in the previous section, and looks for the value of VDP in the pointer table that is closest to this. The machine reads the values of VD, VB, and VL that are in this row of the pointer table.
The machine will then use these values of VD, VB, and VL during copying until the next process control self check. These values are designed to bring the actual V
DP
to the optimum value for the machine’s current condition.
VD: Drum potential without exposure - to adjust this, the machine adjusts the
charge corona grid voltage (VG)
VL: Drum potential with the strongest exposure - to adjust this, the machine
adjusts the laser diode input current (ILD)
VB: Development bias
2-10
24 February, 1999 PROCESS CONTROL
2.1.4 PROCESS CONTROL
What is process control
γγγγ
?
γγγγ
CORRECTION
After process control, the proper values for VD, VB, VL have been defined for the maximum laser power. However, the medium (greyscale) range is ignored. To improve this situation, a new process called ‘process control gamma correction’ is done after potential control. This process defines a suitable LD output for all 256 grades of the greyscale.
Process control gamma correction takes about 30 seconds.
How is it done?
ID sensor
output
Target
B
C
Actual
Actual LD
value
VSP range
D
Detailed
Descriptions
D
A
Input LD value
A
Target LD value
A259D556.WMF
Based on the maximum laser power just defined during the process control self check, the machine writes another 16-grade sensor pattern on the drum.
NOTE:
This is different from the sensor pattern made during potential control – that pattern always uses 16 fixed laser power levels.
The ID sensor detects the density developed on these patterns and compares them with the target densities in ROM. The target densities and the actual densities can be plotted as shown in the diagram above left.
NOTE:
To make the curve of actual densities, the machine draws a curve through the density points read from the 16-grade pattern made for process control gamma.
From this, the machine determines how much to correct the LD power when attempting to write a certain density on the drum.
In the example in the diagram, for a laser power of A, the machine expected an ID of B. However, the actual result was C. To get an ID of B, the machine has to use a laser power of D. The expected ID can be plotted against the actual ID as shown in the diagram above right; this is the process control gamma curve.
Process control γ target values are stored in the NV-RAM on the main control board. The CPU calculates the process control γ on this board. The results of the process control γ calculation go to the LD main control board to compensate the LD input data.
The process control gamma obtained cannot be adjusted in SP mode.
2-11
PROCESS CONTROL 24 February, 1999
Process control gamma correction timing
The machine automatically does process control gamma correction at the end of every process control self check.
2-12
24 February, 1999 TONER SUPPLY CONTROL

2.2 TONER SUPPLY CONTROL

2.2.1 TONER SUPPLY CONTROL METHOD

This machine has two toner supply control meth ods: fuzzy control mode, and fixed supply mode.
Normally this machine uses fuzzy control. The fixed supply method is used only when abnormal conditions occur during the process control self check.

2.2.2 FUZZY CONTROL MODE

Copy
Vsp Detection for Toner
Supply Control
Fuzzy Control
Required Amount of Toner
is Determined
Toner Supply Motor
Duration is Calculated
Detailed
Descriptions
Image Area Ratio
A259D668.WMF
First, the machine assesses the amount of toner per unit ar ea on the dru m (M/A) . This is determined from two sensor inputs: Vsg, and Vsp(toner).
The fuzzy logic algorithm then uses the most recent M/A values to assess current toner density conditions.
The output from the fuzzy logic process is then combined with the image area ratio obtained from the image data signal coming from the IPU board. The result of this calculation is the amount of toner required, and from this, the machine determines the time that the toner supply motor must stay on in order to supply the correct amount of toner.
2-13
TONER SUPPLY CONTROL 24 February, 1999
2.2.3 VSP DETECTION FOR TONER SUPPLY CONTROL
The copier generates an ID sensor pattern using a
20 mm
standard laser diode power. The copier generates this pattern between the K, C, M, and Y images, and then detects the density using the ID sensor. The result is
20 mm
known as ‘VSP for toner supply control’, or ‘VSP (toner)’ to distinguish it from the ot her VSP, measured during potential control.
This process is done after
Each color development cycle for odd-numbered copies when making
A259A015.WMF
continuous copies of A4/LT landscape size or smaller.
Each color development cycle, every copy in all other modes.

2.2.4 CALCULATING THE AMOUNT OF TONER ON THE DRUM

A259D552.WMF
Y, M, C toner
A259A009.WMF
K toner
First, the machine calculates a value from the current VSP (toner) value. Then, it refers to a table in the ROM to determine the toner density on the drum (M/A).
M/A: Toner amount per unit area on the drum (mg/cm2)
The target M/A for toner supply control is 0.4 mg/cm2 for the C, M, and Y toners and 0.3 mg/cm2 for the K toner. M/A is calculated in the same way as for potential control.
Fuzzy Logic Algorithm
The fuzzy logic algorithm has two input factors which are related to the amount of toner on the drum. These are:
The difference between the average of the previous 10 M/As and the target M/A
The tendency of the previous 10 M/As
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24 February, 1999 TONER SUPPLY CONTROL
Image Area Ratio
This is a measure of how much toner will be needed for each color on a page. From the image data from the image processing unit (IPU), the machine determines the total amount of the color on the page. It takes into account the grayscale values for each pixel for that color.

2.2.5 FIXED SUPPLY MODE

In fixed supply mode, the machine adds a fixed amount of toner to the developer every copy. Readings from the ID sensor are ignored.
SP 2-208-005 to 008 define the toner supply ratios for each color in fixed supply mode.

2.2.6 TONER SUPPLY IN ABNORMAL SENSOR CONDITIONS

The machine detects that the ID sensor is abnormal if the detected VSG value is out of the required range three consecutive times during process control. After that SC 385 is displayed and logged. Switching the main switch off/on recovers the machine and the toner supply method falls back to fixed supply mode.
If the abnormal condition is recovered during the next process control, the machine automatically selects the fuzzy control mode again.
Detailed
Descriptions
2-15
TONER SUPPLY CONTROL 24 February, 1999

2.2.7 DETECTING TONER NEAR END/END

0.4 0.6
YMC Toner K Toner
A259D554.WMF
0.25
A259D555.WMF
Toner Near-end
For the Y, C, and M toners, the copier first detects toner near-end using the toner end sensor (see ’Development – Toner End Detection’). The toner end sensor detects the toner end condition during development. Then, VSP is checked. If both toner end sensor and VSP indicate near-end, the machine indicates a near-end condition for that color.
For K toner, the copier detects the toner near end condition using the ID sensor only. Light cannot pass through K toner as well as C, M, or Y. So toner adhering to the window inside the toner hopper blocks the light returning to the sensor. Therefore the copier cannot accurately detect how much K toner remains using the toner end sensor.
Toner End
After a toner near-end condition is generated, the copier uses the write mode pixel counter and sheet counter to detect toner end. This is done in the same way for all colors (K, C, M, and Y).
2-16
24 February, 1999 TONER SUPPLY CONTROL
Toner near end detection
Toner end sensor
The toner end sensor detects light reflected from a mirror inside the toner hopper (see ‘Development – Toner End Detection’). There are two levels of output, namely High (5V: no reflection/toner present) and Low (0V: reflection detected/no toner).
For C, M, and Y toners, the toner near end detection routine using VSP begins when the toner end sensor detects four consecutive low signals.
This sensor does not work for K toner because toner adhering to the window blocks reflection back to the sensor. For K toner, only VSP is used.
Detailed
Descriptions
Toner near end detection routine using V
SP
Toner near end is displayed on the operation panel when the amount of toner (M/A) calculated during toner supply control is less than the target supply (0.4 mg/cm2 for C, M, and Y; 0.25 mg/cm2 for K) five times in succession.
Toner end detection
When a color reaches the toner near-end condition, 10 more pages can be made with that color.
Then, if during those 10 pages, the pixel count for the color in question reached 500%, the copier displays toner end for that color and that color cannot be used. (100% is defined as one A4 image with the color in question covering the whole page at full strength.)
If the pixel count has not yet reached 500% after 10 pages, copying can continue until the pixel count reaches 500%. Then, the copier displays toner end for that color and that color cannot be used.
If the pixel count reaches 500% during the first 10 pages, copying is not stopped, but that color toner may appear pale on the output.
This process is the same for the K, C, M, and Y toners.
2-17
TONER SUPPLY CONTROL 24 February, 1999
Toner end recovery
The copier enters the recovery process in the following cases:
1. The front door is opened and a toner cartridge is removed or inserted. This is regarded as an ordinary replacement procedure for the toner cartridge.
W hen the door is opened, the copier moves the next-to-be-replaced color
toner cartridge to the replacement position.
↓↓↓↓
Replace the toner cartridge.
↓↓↓↓
The copier enters the toner replenishment confirmation mode after the toner
cartridge is replaced.
NOTE:
If recovery is needed for two colors, the copier proceeds with the next color if the door is opened or if the user specifies at the operation panel that the first color should be skipped.
2. If the copier is turned off and on, it assumes that toner cartridges for all colors have been replaced and enters the toner replenishment confirmation mode for all colors.
Toner replenishment confirmation mode
1. For color toners, the copier moves the toner cartridge of the first color to be subject to toner replenishment confirmation to the toner end sensor detection position (K, then Y, then C, then M). The copier does not use the toner end sensor for the K toner (it uses VSP). However, it moves the revolver to the toner end sensor when confirming toner replenishment for the K toner.
2. The copier rotates the toner cartridge for a certain period.
3. The machine checks whether toner is present. For the C, M, and Y toners, the copier uses the toner end sensor. For the K toner, the copier measures VSP.
4. The copier moves the toner cartridge for the next color to the toner end sensor detection position and performs steps 2) and 3).
5. When the toner replenishment confirmation cycle ends, the copier moves the toner cartridges to the detection position for the toner end sensor. The copier then checks again whether toner is present. If toner is found to be not present, the copier returns that cartridge to what it was before the toner recovery procedure started (toner near end or toner end).
6. The copier resets the toner near end and toner end states and resets the toner end related counters (pixel and sheet counters)for cartridges which the machine detects to be full.
Toner replenishment confirmation mode takes several seconds for the C, M, and Y toners and 20 to 30 seconds for the K toner.
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24 February, 1999 DRUM UNIT

2.3 DRUM UNIT

2.3.1 OVERVIEW

[D]
[E]
[B] [C]
[F]
[A]
A259D201.WMF
[G][H]
[I]
Detailed
Descriptions
[J]
[K]
The drum unit is to the right of the drawer unit. It can easily be removed by pulling out the drawer unit.
The drum unit consists of the OPC drum [A], the charge corona unit [B], a quenching lamp [C], the drum potential sensor [D], the ID sensor [E], the carrier catcher [F], and a cleaning unit [G]. The cleaning unit is integrated in the drum unit to prevent toner from spilling o ut into the machine.
The cleaning unit is made up of the cleaning blade [H], the lubricant bar [I], the cleaning brush [J], and the pre-cleaning corona (PCC) [K].
The drum turns anticlockwise as viewed in this drawing.
2-19
DRUM UNIT 24 February, 1999

2.3.2 DRIVE MECHANISM

[D]
[C]
[B]
[A]
A259D202.WMF
The drum motor [A] (a brushless motor) drives the drum via gears and a timing belt. This motor also drives the cleaning unit using a timing belt [C].
This motor contains a drive controller circuit, which controls the drum rotation. Since the drum shaft does not pass all the way through the drum from front to rear,
a flywheel [D] is mounted on the shaft at the rear of the drum to eliminate uneven drum rotation.
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24 February, 1999 DRUM UNIT

2.3.3 DRUM CHARGE

[B]
[C]
Detailed
Descriptions
A259D203.WMF
[A]
This copier uses a single wire scorotron corona unit to charge the drum. The single corona wire applies a negative charge to the drum surface (–670 V is
the standard voltage). The stainless steel grid plate [A] makes the corona charge uniform.
The high voltage supply – C, G [B] supplies a constant voltage (–5 kV) to the corona wire, and controls the grid voltage.
The charge corona unit contains a cleaner. The wire and grid can be cleaned by sliding the charge corona unit forward and backward.
The main exhaust fan [C] at the rear of the copier causes air to flow through the charge corona unit from front to rear. This prevents uneven charging. The air also flows over the ID sensor, keeping it clean.
2-21
DRUM UNIT 24 February, 1999

2.3.4 DRUM CLEANING

[A]
[E]
[C]
[B]
[D]
A259D204.WMF
Pressure is continuously applied to the lubricant bar above the cleaning brush by a spring [A]. The cleaning brush [B] spreads out the toner remaining on the drum, which makes it easier for the cleaning blade to remove. The brush collects toner from the drum surface and the cleaning blade [C] scrapes off the remaining toner on the drum. The toner falls onto the toner collection coil [D]. The toner collection coil transports the toner to the used toner tank.
The cleaning blade is angled against drum rotation for improved cleaning efficiency. The spring [E] maintains a constant downward pressure on the cleaning blade.

2.3.5 PCC

[A]
A259D206.WMF
The PCC [A] removes uneven charge on the drum, which means that it is not necessary to make one extra drum rotation before charging. This reduces the copy time for the first sheet of paper.
2-22
24 February, 1999 DRUM UNIT

2.3.6 QUENCHING

[A]
A259D205.WMF
The quenching lamp [A] is a row of LEDs. It turns on immediately after the Start key is pressed and the drum motor starts. The light is red, to protect the drum from optical fatigue.
Detailed
Descriptions

2.3.7 CARRIER CATCHER

[A]
There is a magnet [A] below the ID sensor. This removes weakly-magnetic worn carrier particles from the drum, preventing them from falling on to the copy paper and causing copy quality problems such as firefly spots.
A259D201.WMF
2-23
SCANNER UNIT 24 February, 1999

2.4 SCANNER UNIT

2.4.1 OVERVIEW

[A] [B][C][D]
[E]
An image of the original illuminated by the exposure lamp [A] (a halogen lamp) is reflected onto a color CCD [B] (Charge Couple d Device) via the 1st [C], 2nd [D], and 3rd [E] mirrors, filter, and lens. The filter removes infra-red from the light reflected off the original; this is particularly important for glossy photos with black areas, which can appear reddish in copies.
The number of scans depends on the copy mode (black, full color, auto color select, or single color). The scanner moves 4 times at most, once for each development cycle. The order of the cycles is black, yellow, cyan, and magenta. The CCD is a one-chip color CCD with an RGB color filter. The scanning resolution is 400 dpi (5,000 pixels).
A259D001.WMF
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24 February, 1999 SCANNER UNIT

2.4.2 SCANNER

[C][D]
[A] [B] [F]
[E]
A259D001.WMF
The 1st scanner consists of the exposure lamp [A], main and sub reflectors [B], and 1st mirror [C]. This model uses a halogen lamp with nine elements. The frosted surface of the exposure lamp ensures even exposure in the main scan direction.
Detailed
Descriptions
The exposure lamp is energized by a dc supply to avoid uneven light intensity caused by power fluctuations while the 1st scanner moves in the sub-scan direction. The sub reflector is shaped so that light will expose the original evenly. This reduces shadows on pasted originals.
The 1st [C], 2nd [D], and 3rd [E] mirrors have glass on the reverse sides to increase their weight. This prevents the mirrors from vibrating.
The thermostat [F] in the 1st scanner protects against overheating. It will break at around 140 °C and cannot be reset.
2-25
SCANNER UNIT 24 February, 1999

2.4.3 SCANNER DRIVE

[B]
[A]
[B]
A259D002.WMF
A five-phase stepper motor [A] drives the scanner. This motor drives the 1st [B] and 2nd [C] scanners via two scanner wires. The wires at the front side and the rear side are the same, for easy assembly.
In full size mode, the 1st scanner speed is 156 mm/s during scanning, and 1638 mm/s when the scanner returns. The 2nd scanner speed is half that of the 1st scanner.
Forwarding Speed Returning Speed Full Size Mode Reduction or
Enlargement Mode
156 (mm/s) 1638 (mm/s)
156/M (mm/s) 1638 (mm/s)
In reduction or enlargement mode, the scanning speed depends on the magnification ratio (M: 0.25 to 4.00) i.e., 156/M mm/s. The returning speed is always the same (1638 mm/s). The image length is changed in the sub-scan direction by changing the scanner speed, and in the main scan direction by image processing on the scanner IPU board.
The number of scans depends on the color selection mode as shown in the following table:
Mode
Black and White
Auto Color Selection
Single Color Full Color 4
For Black and White Originals
For Colored Originals For Y, C, or M 1 Y, C, M
For G, R, or B
Number of
Scans
1K 1K
4
2
Development Order
K Y C M
Y C, Y M, C M K Y C → M
2-26
24 February, 1999 SCANNER UNIT

2.4.4 COLOR CCD

1
R
G
B
5
9
2 31
5000
A259X001.WMF
Detailed
Descriptions
The color CCD converts light reflected from the original into three analog signals, one for each of the three basic colors Red, Green, and Blue. The signals are called the R, G, and B signals. Each of the four scans (for toner colors YMCK) generates a separate set of three signals (RGB).
The CCD consists of three lines of 5000 elements at a resolution of 400 dpi (15.7 dots/mm). To make the R, G, and B signals, each line has a color separation filter (R, G, or B). The lines are spaced 4 pixels apart for full size magnification. To correct for the spacing, the R, G, and B signals must be synchronized. This is done by delaying the signals in memory buffers on the scanner IPU board (the Image Processing section contains more details).
The CCD is mounted on the board with the lens block (the assembly is known as the SBU (Sensor Board Unit). Therefore, to replace the CCD, repla ce the SBU.
2-27
SCANNER UNIT 24 February, 1999

2.4.5 WHITE PLATE SCANNING

[A]
[B]
A259D801.WMF
There is a white plate [A] for auto shading, stuck on the exposure glass [B] underneath the left scale. When this white plate is scanned, the output from all the CCD elements in a line should in theory be equal, but actually it is no t, for the following reasons:
Variations in sensitivity between elements of the CCD
Variations in characteristics of lens and mirror reflectivity
Loss of brightness toward the ends of the exposure lamp
To correct for this uneven output from the CCD elements, the light reflected from the white reference plate is scanned. This is known as auto shading.
Auto shading is done every copy cycle at the scanner home position before starting the first scan.

2.4.6 SCANNER IPU BOARD

The scanner IPU board processes the RGB signal received from the CCD board and controls the following under the control of the main control board.
1. Controls exposure lamp on/off switching and voltage
2. Controls the speed of the scanner drive motor
3. Detects the original paper size
4. Controls on/off switching for the scanner exhaust and optics cooling fans
5. Supplies the clock signals for the CCD board
6. Detects when the scanner is at home position
2-28
24 February, 1999 SCANNER UNIT

2.4.7 ORIGINAL SIZE DETECTION

[D]
[B]
[C]
[A]
A259D003.WMF
There are three APS sensors (reflective photosensors) in the optics cavity for original size detection. The original width sensor [A] detects the original width, while the original length sensors [B] and [C] detect the original length.
The original width sensor [A] and the original length sensor [B] have two internal beams. Each beam scans a different point of the exposure glass. The other original length sensor [C] uses only one beam.
If the original or platen cover is present over the scanning point for a particular sensor, the beam is reflected, and each reflected beam activates a photoelectric device.
Original Size
A4/A3 Version (metric)
A3 11 x 17 -- 1 1 -- -­B4 10 x 14 1 0 1 -- -­F4 8
A4-L 8 A4-S 11 x 8 B5-S 11 x 8
B5-L 8
A5-L 5
LT/DLT
Version
(inch)
1/2
x 14 0 -- -- -- 1
1/2
x 11 0 -- -- 1 --
1/2
x 11 0 -- 1 -- --
1/2
x 8
APS1 APS2 APS3 APS4 APS5
1/2 1/2
1/2
-- 1 0 -- -­1 0 0 -- --
0 -- 0 -- -- See Note
Metric: F4, F, or Folio, depending
SP5-126-001
on
Detailed
Descriptions
L: Lengthwise S: Sideways 0: No paper, 1: Paper present, --: Don’t care The diagram on the next page shows where the APS sensors are.
2-29
SCANNER UNIT 24 February, 1999
The machine cannot recognize the size of the original on the exposure glass if it is A5 lengthwise/HLT or smaller. Therefore, when all sensor outputs are off, the machine either will detect A5 lengthwise/HLT or will display an error message stating that it cannot detect the size of the original (this depends on SP 4-303).
248.5
273.5
71
62.2
316
273.5
248.5
150
APS3
APS1
APS2
Unit: mm
APS4
APS5
A259D800.WMF
While the main switch is on, these sensors are active and the original size data is always sent to the main CPU. However, the main CPU checks the data only when the platen cover is open.
The check starts when the platen cover position sensor ([D] on the previous page) turns on; this is when the platen is about 15 cm above the exposure glass. At this time, only the sensors beneath the original receive the reflected light and are on; all other sensors are off.
The main CPU can recognize the original size from the signals from the sensors. If a copy is made with the platen open, the main CPU determines the size of the original from the sensor output at the time that the start key is pressed.
This original size detection method eliminates the necessity for pre-scanning, which increases the productivity of the machine.
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24 February, 1999 SCANNER UNIT

2.4.8 OTHERS

[B]
[A]
[C]
A259D004.WMF
Anti-condensation Heater
There is an anti-condensation heater [A] on the left side of the optical base plate. It turns on when the main switch is off (if the machine is plugged into the wall outlet), to prevent moisture from forming on the optics.
Detailed
Descriptions
Fans
Optics Cooling Fan
The optics cooling fan [B] is on the left side of the optics cavity. The fan sends air into the optics cavity to prevent the exposure lamp and optics cavity from overheating during copy cycles. This fan is on only when the exposure lamp is on.
Optics Exhaust Fan
The optics exhaust fan [C] is on the right rear side of the optics cavity. This fan moves air out of the optics cavity to keep it from overheating. This fan is always on when the main switch is on. During the ready condition, the rotation of the fan drops to 2/3 of the full speed.
2-31
IMAGE PROCESSING 24 February, 1999

2.5 IMAGE PROCESSING

2.5.1 OVERVIEW

+
Scanner IPU Board
CCD
Scanner
Section
IPU
Section
Scanner
PD
+
LD Unit
LD
LD
Drive
Board
LD
Main
Control
Board
Image
Data
Main
Control
Board
Printer
A259X002.WMF
The light from the exposure lamp is reflected by the original onto the CCD board. The CCD board has a CCD (Charge Coupled Device) with a three-line (RGB) f ilter. The reflected light is converted to analog image data signals, and these are transferred to the scanner IPU board.
The scanner IPU board does the following: A/D conversion (to 10-bit data), shading, D/A conversion for shading compensation, scan line correction, and image processing. In the IPU section, image data (10 bit) is converted to 8-bit data. This 8-bit data is sent from the scanner IPU board to the LD main control board.
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24 February, 1999 IMAGE PROCESSING

2.5.2 SCANNER SECTION BLOCK DIAGRAM

R
Analog
ASIC
AD
Converter
10bit
10bit
Field
Memory
10bit
G
CCD
B
AGC
Analog
ASIC
AGC
Analog
ASIC
AGC
D/A
Converter
AGC (Auto Gain Control):
Ref
AD
Converter
Ref
AD
Converter
Ref
10bit
CPU
Shading
Circuit
Controls the amplification factor for the signals, using
4 Mbit
Field
Memory
2 Mbit
10bit10bit
the white level signal that is fed back from the shading circuit.
10bit10bit
A259X003.WMF
IPU
Section
Detailed
Descriptions
2-33
IMAGE PROCESSING 24 February, 1999

2.5.3 SCANNER SECTION

Photoelectric Conversion (by the CCD)
The color CCD converts the light reflected fro m the original into RGB analog signals (6.615 MHz for each signal: even-pixel and odd-pixel). Each CCD line has 5,000 pixels and a resolution of 400 dpi (15.7 pixels/mm).
Signal Processing (in the Analog ASIC)
(1) Signal Amplification
Operational amplifiers boost odd-pixel and even-pixel RGB analog signals from the CCD.
(2) Signal Composition
For each color, the two amplified signals (even-pixel and odd-pixel) are combined by the multiplexer inside the Analog ASIC before A/D conversion.
(3) Feedback
The CPU on the scanner IPU board receives the white level and black level from the shading circuits. Then it feeds this data to the clamps and the operational amplifiers inside the Analog ASIC through the D/A converter (see D/A Conversion). The CPU updates the black and white level every time the main switch is turned on.
A/D Conversion
The A/D Converter converts the analog signals (for each RGB color) to 10-bit digital signals (1024 grades) per pixel.
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24 February, 1999 IMAGE PROCESSING
Shading Circuit
[A]
A259D509.WMF
(1) Shading Compensation
Before scanning each original, the machine generates a reference white waveform (also known as "white shading data") by scanning 5 mm of the white reference plate [A] in the sub-scan direction (this equals 79 lines at 100% magnification).
Detailed
Descriptions
The white shading data is calculated for each pixel across the main scan. To do this for a particular pixel, the machine takes the white levels for that pixel on each of the main scan lines taken from the white reference plate, and calculates a value from these. The white waveform is made by repeating this process for each pixel across the main scan.
To improve image reproduction for high-density areas, the machine also measures the black shading data. It does this by reading the black video level at the first 4 pixels of the CCD, which should be black because these pixels are masked off. The average of the 4 pixels is represented as the black shading data for one CCD scan line.
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IMAGE PROCESSING 24 February, 1999
White Correction
Black Correction
1 line
1023
0
1 line
A259X005.WMF
The shading circuit corrects the video signal for each pixel obtained during image scanning as follows:
(Video data for each pixel) – (Black shading data for each line)
(White shading data for each pixel) – (Black shading data for each line)
X 1023
The white shading data is updated before every first scanning (2C and 4C mode) or every scanning (1C mode). The black shading data is updated every scan line. The white shading data is used to correct the image data for irregularities in the CCD and in the optics across the main scan. The black shading data is used to correct the image data for any changes in black level with time, while the machine scans down the page.
(2) Main Scan Timing
The shading circuit generates the CCD timing signals, and the timing signals for feeding back the black and white level data from the shading circuit to the Analog ASIC.
(3) Sub-scan Timing
The shading circuit also generates the synchronization signal for scan line correction (see the next page for details on this process).
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24 February, 1999 IMAGE PROCESSING
D/A Conversion
The CPU monitors the digital feedback signals from the shading circuits and calculates correction factors. Then the D/A circuit converts the signals from the CPU into analog signals and feeds them back to the operational amplifiers and the clamps inside the Analog ASICs. Black shading data is fed back to the clamps to provide a black level reference. This is done for every CCD pixel to calibra te the black level, and avoid drifts in the signal with time.
Scan Line Correction
The three CCD lines providing the RGB signals are spaced 4 line s apart on the original image (when the user selects full size magnification). To compensate for this discrepancy, the scan line correction circuits synchronize the output timing of the RGB signals with the IPU section by storing the scan data for each line in memory. As the discrepancy between RGB video signals changes depending on the magnification ratio, the correction data is calculated as follows:
Detailed
Descriptions
Enlargement
Reduction
Full Size
B
5 lines 5 lines
B
3 lines
B
1 2 3 4 5 6 7 8 9 10 11 12 13
G R
4 lines 4 lines
G R
3 lines
G R
A259X006.WMF
B: Standard (No correction) G: (4 lines) x (Magnification ratio) R: (8 lines) x (Magnification ratio)
If this calculation does not result in an integer, the correction data is set to the closest integer, but further correction is needed (refer to IPU Section – Picture Element Correction).
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IMAGE PROCESSING 24 February, 1999
 
 
 


2.5.4 IPU SECTION BLOCK DIAGRAM

Panel
Operation
LD
Main
Control
1 bit
γ
Main
Printer
Mirror
(gamma)
Scan
Magnifi-
cation.
8 bit
 
Color
Conver-
sion
Main
16 bit
2 pixel
Correction
Board
Control
(VRAM)
DRAM
IPU Section
Section
Scanner
3 bit
Auto Text/
CPU
Support
ACS
Photo
Separation
ASICs
8 bit
Filter• Positive/
Field
Memory
Picture
Element
Field
Memory
Color
Negative
Conversion
8 bit
Field
8 bit
(gamma)
Scanner
Correction
γ
Correction
10 bit
8 bit
Memory
 
Area
 
DRAM
Treatment
16 MB
CPU
2-38
Circuit
Shading
: A260 machine only
10 bit
A259X007.WMF
24 February, 1999 IMAGE PROCESSING



2.5.5 IPU SECTION

Picture Element Correction and Scanner Gamma Correction
(1) Picture Element Correction
R G B
A259D803.WMF
Picture Element Correction
The Picture Element Correction circuit does two things.
1. Completion of the Scan Line Correction process
The discrepancy in the spacing of the RGB signals from the CCD in the sub-scan direction is corrected by the line correction circuit in the scanner section (refer to Scanner Section – Scan Line Correction). However, if the correction data corresponding to the magnification ratio is not an integer, then further correction is needed to synchronize the RGB signals.
Detailed
Descriptions
2. Correction if the CCD is not perpendicular to the light
If the CCD board is not perpendicular to the light axis, the position of each pixel is different from the original image position. This difference becomes larger towards the ends. Under this condition, vertical black lines (in the sub-scan direction) at the left and right edges of the original are colored because the Y, M, and C toner dots are not properly positioned. (This can be checked by looking at the vertical lines at the right and left edges of a copy of the C4 color chart.)
Therefore, the CCD line spacing is also corrected here. The target areas for this correction are shown above. The green CCD line is taken as a standard, and the ends of the red and blue lines are corrected.
Adjust SP modes 4-932-001 to 4-932-004 to chang e the v erti cal line correction level.
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IMAGE PROCESSING 24 February, 1999
(2) Scanner Gamma Correction (RGB Gamma)
Image Data
1023
0
Dark Light
Fig. 1
Scanner Input
A259X008.WMF
RGB Signal After Scanner γ Correction
255
0
Fig. 2
Image
1023
LightDark
Data
A259X009.WMF
The RGB video signals from the CCD are converted to 10-bit digital signals in the scanner section and sent to the IPU section. These signals are proportional to the intensity of light reflected from the original image (Fig. 1). However, the IPU section converts the signal levels as shown in figure 2 by using a gamma (γ) correction table in order to improve the accuracy of RGB to CMY color conversion, which is done later in the image process. The same table is used for R, G, and B signals.
The scanner gamma (γ) correction inverts the video signals and converts the signal from 10-bit to 8-bit as outlined in the following table:
Dark (Black) Light (White)
Scanner Input (RBG) 0 1023
After γ Correction (RGB)
Color Conversion
Printer Output (CMYK) 255 0
255 0
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24 February, 1999 IMAGE PROCESSING
ACS (Auto Color Selection)
A259D511.WMF
Auto color selection mode determines if an original is black/white or color. Then black copy mode or full color mode is automatically selected to match the original.
Detailed
Descriptions
To recognize if the original has a color area or not, the RGB video signals are compared. If the maximum difference among RGB signal levels (MAX-MIN in the above diagram) is within a certain range, the pixel is considered black and white.
During the 1st scanning cycle, the latent image is developed with the amount of black toner specified by the gamma (γ) corrected RGB video signals. If the original does not have any color areas, the 2nd scanning is aborted and the developed image is transferred from the transfer belt to the copy paper. Then the black and white copy comes out. If the original has a color area, copying resumes in the full color copy mode (4 scans).
Users can maximize the quality of their output by selecting priority for Bk or full color original in ACS mode, using a User Tool (the default is Bk). The Bk setting prevents the UCR process from reducing the image density too much in low image density photo areas. This is explained in more detail in the section on UCR.
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IMAGE PROCESSING 24 February, 1999
Auto Letter/Photo Separation
Text Area
A259D512.WMF
In auto text/photo mode, the original image is separated into text and photo areas (dot screen areas).
"Text" refers to an original or area of an original that contains text and/or line drawings.
Generally, text areas have strong contrast between the image and the background. However, photo areas (dot screen areas) have a less extreme range of contrast levels.
Using these characteristics, the original image is separated into black text areas, colored text areas, and photo areas. The machine uses the following three separation methods to detect the different data areas, and the final evaluation circuit analyzes the output from these three processes to determine the result.
Edge Separation
Black Text
Colored Text
Dot Screen Separation
Colored Text Separation
Photo
A259D513.WMF
(1) Edge separation
The edges of text and line diagram elements are identified by using the following characteristics: strong contrast, continuity of black or color pixels, continuity of white pixels around the black or color pixels
The machine can do this by only referring to the green signal.
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24 February, 1999 IMAGE PROCESSING
(2) Dot screen separation
Dot screen areas are separated from non-dot screen areas (mainly text). The machine determines that if white pixels are not detected around the non-white
pixels, it is a dot screen area. The machine can do this by only referring to the green signal.
(3) Colored text separation
Black pixels and color pixels in text areas are identified by determining the difference among the RGB maximum signal levels and the output levels of the RGB video signals.
(4) Final evaluation circuit
The separation signal accompanies the data as it passes to the further stages of image processing. The separation signal tells the image processing circuits whether the data is black text, color text, or photo. The text areas are processed in text mode and the photo areas are processed in photo mode in the subsequent image processing steps.
Detailed
Descriptions
Auto text/photo separation is mostly effective only for small characters or thin line diagram elements. If there are large characters or solid line drawing elements in the original, only the edges of these are processed using text mode; the inner regions are processed using photo mode.
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IMAGE PROCESSING 24 February, 1999
Filtering and Color Conversion
(1) RGB Smoothing Filter
Photo Text
Before
After
A259D514.WMF
A259D515.WMF
A259D521.WMF
Depending on the results of auto text/photo separation (or depending on the selected original mode), the appropriate software filters are applied to the RGB video signals. The RGB smoothing filter is applied to photo areas; an edge emphasis filter is applied to text areas.
(2) Background Density Control and ADS (Auto Image Density Selection)
a. Background Density Control
A259D522.WMF
A259D524.WMF
This function removes low ID image signals (background) that are less than a certain threshold. The threshold that is applied depends on the color mode (single color or full color). For each of these modes, the user can select a different threshold.
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24 February, 1999 IMAGE PROCESSING
b. ADS (Auto Image Density Selection)
A259D523.WMF
In ADS mode, the user does not set the threshold; the machine calculates it, guided by input from the user for F/C and 2C mode (there are 5 settings in the “User Tools” menu).
Detailed
Descriptions
In full color mode, after the first scanning (Bk) the machine calculates the threshold for removing background by referring to the RGB data taken from the entire original.
In black and white mode, the machine detects the background level for the original, also known as the peak white level, and removes this from the image, to make a white background. Peak level data is taken for each scan line to correct for changes in background density down the page. From the peak white level, the machine determines the white reference value for A/D conversion. Therefore, in black and white mode the background density is controlled before data is input to the A/D converter.
(3) Positive/Negative Reverse
In the positive/negative mode, colors are changed to their complements as shown.
Red ↔ Cyan Green ↔ Magenta Blue ↔ Yellow
Y
û û
2-45
R
MC
G
K B
A259D804.WMF
IMAGE PROCESSING 24 February, 1999
(4) Color Conversion
A259D516.WMF
A matrix converts the RGB video signals from each scanning cycle into YMCK video signals. The content of the matrix depends on the selected mode. The transparency for each color toner is not ideal, as shown above. Color conversion compensates for the difference between ideal and actual characteristics.
The following modes affect the matrix: color conversion mode (this is a user mode, not to be confused with the color conversion process described in this section), pastel mode, color balance mode, original mode (press print glossy photo, 2nd generation), RGB toner correction mode.
The following color conversion table is an example of the results from the matrix operation, for simple color copying without any special modes applied. For example, to represent green, the yellow and cyan toners are used in a proportion of 1:1.
Original
Color
Toner
Y11110000
M11000110
C10011100 K10000000
KRYGCBMW
Color Conversion Table
If the user selects a special mode, some of the values in this table may be between 0 and 1. The following page briefly explains the effects of some modes.
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24 February, 1999 IMAGE PROCESSING
A. Color conversion mode
Color conversion mode is a user feature, not to be confused with color conversion (RGB to CMYK) described above. In color conversion mode, a selected color (C/M/Y/R/G/B/K/W) on an original that falls within the recognized thresholds for that color is converted into a different color on the copy. Up to 4 colors can be converted at one time. Convertible colors include C/M/Y/R/G/B/K/W/Yellow Green/Orange/Marine Blue/Beige/Pink/Purple, and 15 user colors (the user colors are for A259/A260 only). Changing the matrix parameters enables color conversion to occur.
For example, when changing Yellow to Black, the coefficients for the Yellow video signal in the color conversion table become: Y: 1, M: 1, C: 1, Bk: 1
B. Pastel mode
In pastel mode, the matrix parameters change, and the output of the combined YMCK data shifts to a value between 100 % and 25 %. There are 9 steps, and the value used depends on the user's selection.
Detailed
Descriptions
C. Color balance mode
In color balance mode, the data output for each color (YMCK) can be changed independently by changing the matrix parameters. There are nine possible values for each color.
D. Original mode
There are three modes within photo mode (Press Print, Glossy Photo, and 2nd Generation) and three types of special original mode (Marker Pen, Inkjet, Map). The machine selects the most suitable matrix for the original type that is selected by the user at the operation panel.
For inkjet mode, the user can select one of three different inkjet gamma (γ) tables to emulate the output of three different types of inkjet printer. (This is done with the User Tools.)
E. RGB toner correction mode
The toner mixing ratios for R, G, and B are adjustable (SP 5-611-001 to 5-611-
006). The adjustments are valid for 2C (R, G, or B) copy mode only.
F. Twin color mode
Twin color mode separates black areas and colored areas. The machine then converts black to one color (that was selected by the user) and all the color areas another color(also selected by the user) so the output has only two colors. For A258, there are 12 selectable colors. For the A259/A260, there are 15 user colors in addition to this.
2-47
IMAGE PROCESSING 24 February, 1999
(5) UCR (Under Color Removal)
Principle
k
B
k
B
k
B
A259D525.WMF
Obtaining the right colors using YMC toner addition does not always work perfectly. For example, if the same quantity of toner for each color (YMC) is put on the paper, ideally the image should become black, but in reality it becomes a dark color, such as dark blue.
To compensate for this, an equal portion of the common ID value for each color is subtracted. This reduces the amount of color toner on the paper, and a proportional amount of black toner is added. This process is known as UCR.
The UCR ratio is the percentage of the common ID value for YMC that is subtracted and converted to black. In the above example, where the UCR ratio is 100%; the entire common ID value is subtracted from Y, M, and C, and converted to K.
In actual use, the UCR ratio depends on the color mode and the image density. For example, when the UCR ratio is 95%, 95% of the entire common ID value is subtracted from Y, M, and C, and converted to K.
2-48
24 February, 1999 IMAGE PROCESSING
Fig. 1
Fig. 3 Fig. 4 Fig. 5
K
Fig. 6 Fig. 7 Fig. 8
In this example, the UCR ratio is 70%.
For a Black Image
Fig. 2
K
Detailed
Descriptions
K
A259D526.WMF
When copying a black image, the ID values for all colors are equal (figure 1). For each color, the ID value is reduced by the amount of the UCR ratio (70% in the example). A black ID value equal to the 70% reduction is added to compensate for the color ID reduction (figure 2).
For a Color Image
When copying a color image, the color ID values differ fr om one another (figure 3). It is treated in two steps.
The ID value for this image is broken down into two parts (figure 4): a set of values equal to the lowest color ID value, and the remainders of the two higher values.
The part with equal values is treated as a black image (see figures 1 and 2), using the 70% UCR ratio. The resulting am ounts are then added to the remainde rs from step 1 (figure 5). The result gives us the ID value for each color and for black (figure 6).
2-49
IMAGE PROCESSING 24 February, 1999
Changes in UCR Ratio with Image Density and Copy Mode
Text Mode
A259D511.WMF
MIN
A259D508.WMF
- Text Areas -
The UCR ratio in text areas is always 100%.
- Photo Areas, with ACS Priority set to Bk -
In photo areas, when the user sets the ACS priority to Bk, UCR begins to replace color toner with Bk toner at low image densities (when the RGB common value [MIN] is about 13). This prevents excessive reduction of the image density in low image density areas.
At this point, the UCR ratio is zero. As shown in the graph at the top right of the page, it gradually rises with the image density, and the UCR ratio is about 100% when MIN is 255.
- Photo Areas, with ACS Priority set to Full Color -
When the user se ts the ACS priority to Full Color, the UCR process does not be gin to replace color toner with Bk toner until a low-medium image density (when MIN is about 102).
At this point, the UCR ratio is zero. It gradually rises with image density, and the UCR ratio is about 95% when MIN is 255.
UCA (Under Color Addition)
Using only UCR processing, the copy lacks depth. So, a specified ratio of toner is always added for each color (YMC only). The amount of additional toner is proportional to the density of that color on the copy.
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24 February, 1999 IMAGE PROCESSING
Main Scan Magnification
A259D527.WMF
The machine changes the scanner speed to reduce or enlarge the original in the sub-scan direction. However, an LSI on the IPU Board handles reduction and enlargement in the main scan direction.
Detailed
Descriptions
Scanning and laser writing are done at a fixed pitch (the CCD elements cannot be squeezed or expanded). So, to reduce or enlarge an image, imaginary points are calculated that would correspond to a physical enlargement or reduction of the image. The correct image density is then calculated for each of the imaginary points based on the image data for the nearest two true points. The calculated image data then becomes the new (reduced or enlarged) image data.
NOTE:
Mirror Image
The actual calculations for main scan magnification use the polynomial convolution method. This mathematical process is beyond the scope of a service manual and will not be covered here.
Main scan Main scan
Start EndEndStart
Sub scan
Sub scan
û
A259D808.WMF
Each line of video data is transferred to the laser unit in reverse (the end of the line is written on the OPC first).
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