GESTETNER 2635TD, 9035DL, A156, FT5535, 2635 Service Manual

...

Download

SERVICE MANUAL

PN: RCFM5535

A156/A212...SERIES

RICOH GROUP COMPANIES

SERVICE MANUAL

A156/A212...SERIES

RICOH GROUP COMPANIES

A156/A153 A160/A157 A162/A161

SERVICE TRAINING

MANUAL

Rev. 4/98

It is the reader's responsibility when discussing the information contained within this document to maintain a level of confidentiality that is in the best interest of Ricoh Corporation and its member companies.

NO PART OF THIS DOCUMENT MAY BE REPRODUCED IN ANY

FASHION AND DISTRIBUTED WITHOUT THE PRIOR

PERMISSION OF RICOH CORPORATION.

All product names, domain names or product illustrations, including desktop images, used in this document are trademarks, registered trademarks or the property of their respective companies.

They are used throughout this book in an informational or editorial fashion only and for the benefit of such companies. No such use, or the use of any trade name, or web site is intended to convey endorsement or other affiliation with Ricoh products.



LEGEND

PRODUCT CODE COMPANY

GESTETNER

RICOH SAVIN

A156 2635TD FT5535 9035DL A153 2635 FT5035 9035 A160 2627TD FT4527 9027DL A157 2627 FT4027 9027 A162 2822TD FT4522 9220DL A161 2822 FT4022 9220 A207 CMR402 FT5840 9400D A208 CMR321 FT5632 9032 A211 CMR322 FT5832 9032D A206 CMR401A FT5740 9400L A204 CMR401 FT5640 9400 A210 CMR321A FT5732 9032L A212 — FT4622 9122 A214 — FT4822 9122DL

DOCUMENTATION HISTORY

REV. NO. DATE COMMENTS

13/95Original printing 27/95A162/A161 addition 35/97A207/A208/A211 Addition 4 12/97 A212/A214 Addition

The A204 copier is based on the A153 copier. The A206 copier is based on the A155 copier. The A207 copier is based on the A156 copier. The A208 copier is based on the A157 copier. The A210 copier is based on the A159 copier. The A211 copier is based on the A160 copier. The A212 copier is based on the A161 copier. The A214 copier is based on the A162 copier.

Only the differences from the base copiers are described in the following pages. Therefore, this documentation should be treated as an insert version of the base copier’s service manual, although it has a separate binder. It should always be utilized together with the base copier’s service manual.

Rev. 4/98

The Service Training Manual contains information regarding service techniques, procedures, processes and spare parts of office equipment distributed by Ricoh Corporation. Users of this manual should be either service trained or certified by successfully completing a Ricoh Technical Training Program.

Untrained and uncertified users utilizing information contained in this service manual to repair or modify Ricoh equipment risk personal injury, damage to property or loss of warranty protection.

Ricoh Corporation

WARNING

Table of Contents

1. OVERALL MACHINE INFORMATION

1. SPECIFICATIONS..............................................................1-1

2. MACHINE CONFIGURATION.......... .. .................. ..............1-5

2.1 COPIER ......................................................................................1-5

2.2 OPTIONAL EQUIPMENT ...........................................................1-6

3. MECHANICAL COMPONENT LAYOUT........................... 1-7

4. PAPER PATH ................................................................. 1-10

4.1 NORMAL COPYING..................................................................1-10

4.2 DUPLEX COPYING .................................................................1-11

5. ELECTRICAL COMPONENT DESCRIPTIONS ..............1-12

6. DRIVE LAYOUT ............................................................... 1-17

6.1 ALL MODELS ...........................................................................1-17

6.2 A153/A156 ...............................................................................1-18

6.3 A157/A160/A161/A162 ..............................................................1-18

2. DETAILED DESCRIPTIONS

1. PROCESS CONTROL .......................................................2-1

1.1 OVERVIEW..................................................................................2-1

1.1.1 Copy Process aro und the Drum.. ... ... ... ... ......................... ... .. ... ... ..............2-1

1.1.2 Factors Affecting Proce ss Con t ro l ...........................................................2-4

1.1.3 Process Control Pro ce du re s.............................. ......................... ... ... .. ... ...2- 5

1.1.3.1 Copy Image Contr o l............................... .......................... .. ... ... ... ...........2-5

1.1.3.2 Image Density Cont r ol................ ... ... ... .. .......................... .. ... ... ... ...........2-5

1.1.3.3 Drum Potential Control...........................................................................2-5

1.2 COPY IMAGE CONTROL............................................................2-8

1.2.1 Manual ID Correctio n.............................. .. ... ......................... ... ... ... ... ........2-8

1.2.2 Reproduction Ratio Cor rec tion........................ ... ... .. ... ...............................2-9

1.2.3 ADS Correction.............................. ... ... ......................... ... ... .. ... ...............2-10

Rev. 7/95

STM i A156/A160/A162

1.3 IMAGE DENSITY CONTROL ....................................................2-10

1.3.1 Overview............... ... .................................................. ... ... ... .. ..................2-10

1.3.2 V

and V

Detection .........................................................................2-11

1.3.3 ID Correction for the V

Pattern ...........................................................2-12

1.3.4 Toner Supply Control During Copying....................................................2-14

1.3.5 Toner Supply in Abnormal Sensor Conditions........................................2-16

1.4 DRUM POTENTIAL CONTROL.................................................2-18

1.4.1 VR Pattern Correction ...........................................................................2-18

1.4.2 V

Pattern Correction ...........................................................................2-20

1.4.3 T/H Correction ......................................................................................2-23

1.5 PROCESS CONTROL DURING ABNORMAL CONDITIONS ..2-25

1.6 SUMMARY.................................................................................2-26

1.6.1 Process Control and Sensor Detection Timing.......................................2-26

1.6.2 Process Control Checks During Machine Operation..............................2-27

2. DRUM .............................................................................2-32

2.1 DRUM UNIT...............................................................................2-32

2.2 DRIVE MECHANISM ...............................................................2-33

3. DRUM CHARGE .............................................................. 2-34

3.1 OVERVIEW ..............................................................................2-34

3.2 DRUM CHARGE ROLLER DRIVE MECHANISM ..................2-35

3.3 DRUM CHARGE ROLLER CLEANING ....................................2-37

3.4 TEMPERATURE COMPENSATION .....................................2-38

4. OPTICS............................................................................. 2-39

4.1 OVERVIEW .............................................................................2-39

4.2 SCANNER DRIVE ...................................................................2-41

4.3 LENS DRIVE..............................................................................2-41

4.4 HORIZONTAL LENS POSITIONING .......................................2-43

4.4.1 Original Alignment Position ....................................................................2-43

4.4.2 Paper Size ...................... ... ... ... .. .......................... .. ... ... ... .......................2-43

4.4.3 Reproduction Ratio ................................................................................2-43

4.5 3RD SCANNER DRIVE ...........................................................2-45

Rev. 7/95

A156/A160/A162 ii STM

4.6 UNEVEN LIGHT INTENSITY CORRECTION ........................2-46

4.7 ORIGINAL SIZE DETECTION IN PLATEN MODE ................2-47

4.8 AUTOMATIC IMAGE DENSITY CONTROL

SYSTEM (ADS) .........................................................................2-49

5. ERASE.............................................................................. 2-51

5.1 OVERVIEW ...............................................................................2-51

5.2 LEADING EDGE AND TRAILING EDGE ERASE.....................2-52

5.3 SIDE ERASE..............................................................................2-52

6. DEVELOPMENT ..............................................................2-53

6.1 OVERVIEW ..............................................................................2-53

6.2 DRIVE MECHANISM ...............................................................2-54

6.3 CROSS-MIXING ....................................................................2-55

6.4 TONER DENSITY SENSOR ....................................................2-56

6.5 DEVELOPMENT BIAS CONTROL............................................2-57

6.6 TONER SUPPLY .......................................................................2-58

6.6.1 Toner Bottle Replenishment Mechanism ..............................................2-58

6.6.2 Toner Supply Mechanism ....................................................................2-59

6.6.3 Toner End Detection .............................................................................2-59

7. IMAGE TRANSFER AND PAPER SEPARATION ..........2-61

7.1 PRE-TRANSFER LAMP ...........................................................2-61

7.2 IMAGE TRANSFER AND PAPER SEPARATION ....................2-62

7.3 IMAGE TRANSFER AND PAPER SEPARATION

MECHANISM ..........................................................................2-63

7.4 TRANSFER BELT UNIT LIFT MECHANISM ............................2-65

7.5 PAPER TRANSP ORTATION AND BELT DRIVE

MECHANISM ...........................................................................2-66

7.6 TRANSFER BELT CLEANING MECHANISM ..........................2-67

7.7 TRANSFER BELT UNIT RELEASE MECHANISM ..................2-69

8. DRUM CLEANING ..........................................................2-70

8.1 OVERVIEW ..............................................................................2-70

8.2 DRIVE MECHANISM ................................................................2-71

Rev. 7/95

STM iii A156/A160/A162

8.3 CLEANING BLADE PRESSURE MECHANISM AND

SIDE-TO-SIDE MOVEMENT ...................................................2-72

8.4 TONER COLLECTION MECHANISM ......................................2-73

9. TONER RECYCLING ......................................................2-74

9.1 OVERVIEW................................................................................2-74

9.2 NEW TONER AND RECYCLED TONER MIXTURE.................2-75

10. QUENCHING ................................................................. 2-76

11. PAPER FEED AND REGISTRATION ........................... 2-77

11.1 OVERVIEW ............................................................................2-77

11.2 PAPER FEED MECHANISM [A153/A156] ..............................2-78

11.2.1 Drive Mechanism ................................................................................2-78

11.2.2 Slip Clutch Mechanism .......................................................................2-79

11.2.3 Separation Roller Release Mechanism ................................................2-80

11.3 PAPER FEED DRIVE MECHANISM [A157/A160] ...............2-81

11.4 PAPER LIFT MECHANISM ....................................................2-82

11.5 PAPER END DETECTION .....................................................2-85

11.6 PAPER SIZE DETECTION .....................................................2-87

11.7 SIDE FENCE DOUBLE STOPPER

MECHANISM [A157/A160] ....................................................2-88

11.8 LARGE CAPACITY TRAY .......................................................2-89

11.8.1 Paper Lift Mechanism ..........................................................................2-89

11.8.2 Paper Feed Mechanism .......................................................................2-90

11.8.3 Paper End Detection ............................................................................2-90

11.9 BY-PASS FEED TABLE ..........................................................2-91

11.9.1 Table Open/Closed Detection ..............................................................2-91

11.9.2 Feed Mechanism/Paper End Detection ..............................................2-91

11.9.3 By-pass Feed Paper Width Detection .................................................2-92

11.10 PAPER REGISTRATION ......................................................2-93

11.11 PAPER FEED AND MISFEED DETECTION TIMING...........2-94

11.11.1 Paper Feed Tray.................................................................................2-94

11.11.2 By-pass Feed .....................................................................................2-96

Rev. 7/95

A156/A160/A162 iv STM

11.11.3 (A160/A157)........................................................................................2-96

12. DUPLEX ......................................................................2-97

12.1 OVERVIEW..............................................................................2-97

12.2 DRIVE MECHANISM ............................................................2-98

12.3 TURN GUIDE SECTION .........................................................2-99

12.4 DUPLEX ENTRANCE TO DUPLEX TRAY ...........................2-100

12.5 DUPLEX STACKING .........................................................2-101

12.6 PAPER FEED FROM THE DUPLEX TRAY ........................2-102

12.6.1 Tray Lift Mechanism............................................................................2-102

12.6.2 Paper Feed System ...........................................................................2-103

13. IMAGE FUSING........................................................... 2-104

13.1 OVERVIEW ..........................................................................2-104

13.2 FUSING DRIVE AND RELEASE MECHANISM ..................2-105

13.3 FUSING ENTRANCE GUIDE SHIFT MECHANISM .............2-106

13.4 PRESSURE ROLLER ...........................................................2-107

13.5 CLEANING MECHANISM .....................................................2-107

13.6 FUSING LAMP CONTROL ..................................................2-108

13.7 OVERHEAT PROTECTION...................................................2-111

13.8 ENERGY SAVER FUNCTIONS.............................................2-111

13.9 MAIN FUSING LAMP INTERCHANGEABILITY....................2-111

3. AUTO REVERSE DOCUMENT FEEDER A548

1. SPECIFICATIONS..............................................................3-1

2. COMPONENT LAYOUT..................................................... 3-2

2.1 MECHANICAL COMPONENTS .................................................3-2

2.2 ELECTRICAL COMPONENTS ..................................................3-3

3. ELECTRICAL COMPONENT DESCRIPTION...................3-4

4. DETAILED DESCRIPTIONS ............................................. 3-5

4.1 ORIGINAL PICK-UP MECHANISM.............................................3-5

4.2 SEPARATION AND PAPER FEED MECHANISM ......................3-6

4.3 FRICTION BELT DRIVE MECHANISM.......................................3-7

Rev. 7/95

STM v A156/A160/A162

4.4 ORIGINAL SIZE DETECTION ....................................................3-8

4.5 PAPER TRANSPORT MECHANISM ........................................3-9

4.6 THICK/THIN ORIGINAL MODES .............................................3-10

4.7 ORIGINAL FEED-OUT MECHANISM .....................................3-11

4.8 TWO-SIDED ORIGINAL FEED MECHANISM .........................3-12

5. TIMING CHARTS ............................................................3-13

5.1 A4 SIDEWAYS: 1 SIDED ORIGINAL ........................................3-13

5.2 COMBINE 2 ORIGINAL MODE ................................................3-14

5.3 A4 SIDEWAYS: DUPLEX ........................................................3-15

4. PAPER TRAY UNIT A550/A549

1. SPECIFICATIONS..............................................................4-1

2. COMPONENT LAYOUT..................................................... 4-2

2.1 MECHANICAL COMPONENT LAYOUT .....................................4-2

2.2 DRIVE LAYOUT...........................................................................4-3

2.3 ELECTRICAL COMPONENT DESCRIPTION.............................4-4

3. OVERVIEW......................................................................... 4-5

4. DRIVE MECHANISM..........................................................4-6

5. PAPER FEED AND MISFEED DETECTION TIMING .......4-7

5. PAPER TRAY UNIT A553

1. SPECIFICATIONS..............................................................5-1

2. COMPONENT LAYOUT..................................................... 5-2

2.1 MECHANICAL COMPONENT LAYOUT .....................................5-2

2.2 DRIVE LAYOUT...........................................................................5-2

2.3 ELECTRICAL COMPONENT DESCRIPTION.............................5-3

3. OVERVIEW......................................................................... 5-4

4. DRIVE MECHANISM..........................................................5-5

5. PAPER FEED AND MISFEED DETECTION TIMING .......5-6

Rev. 7/95

A156/A160/A162 vi STM

6. SORTER STAPLER A554

1. SPECIFICATIONS..............................................................6-1

2. COMPONENT LAYOUT..................................................... 6-3

2.1 MECHANICAL COMPONENT LAYOUT .....................................6-3

2.2 DRIVE LAYOUT...........................................................................6-4

2.3 ELECTRICAL COMPONENT DESCRIPTION ............................6-5

3. BASIC OPERATION .......................................................... 6-7

3.1 NORMAL MODE AND SORT/STACK MODE ............................6-7

3.2 STAPLE MODE ........................................................................6-9

4. TURN GATE SECTION ................................................... 6-11

5. ROLLER DRIVE AND CONTROL...................................6-12

6. BIN DRIVE AND CONTROL............................................ 6-14

7. JOGGER SECTION ........................................................6-17

8. GRIP ASSEMBLY ......................................................... 6-19

9. STAPLER.........................................................................6-21

10. JAM DETECTION AND STAPLER ERROR.................. 6-24

10.1 SORTER JAMS .......................................................................6-24

10.2 STAPLER ERROR...................................................................6-25

11. TIMING CHARTS ........................................ ................... 6-26

7. SORTER STAPLER A555

1. SPECIFICATIONS .............................................................7-1

2. COMPONENT LAYOUT ................................................... 7-3

2.1 MECHANICAL COMPONENT LAYOUT ....................................7-3

2.2 DRIVE LAYOUT .........................................................................7-4

2.3 ELECTRICAL COMPONENT DESCRIPTION.............................7-5

3. BASIC OPERATION ......................................................... 7-6

Rev. 7/95

STM vii A156/A160/A162

3.1 NORMAL MODE AND SORT/STACK MODE .............................7-6

3.2 STAPLE MODE ..........................................................................7-8

3.3 BIN DRIVE MECHANISM .........................................................7-10

3.4 BIN HOME POSITION ..............................................................7-11

3.5 JOGGER MECHANISM ............................................................7-12

3.6 GRIP ASSEMBLY ..................................................................7-13

3.7 STAPLER UNIT ........................................................................7-14

3.8 STAPLER SWITCH ..................................................................7-15

3.9 PAPER FEED AND MISFEED DETECTION TIMING ............7-16

3.10 JAM DETECTION ...................................................................7-18

8. SORTER A556

1. SPECIFICATIONS..............................................................8-1

2. MECHANICAL COMPONENT LAYOUT........................... 8-2

3. ELECTRICAL COMPONENT LAYOUT............................. 8-3

4. ELECTRICAL COMPONENT DESCRIPTIONS ................8-4

5. BASIC OPERATION .......................................................... 8-5

6. EXAMPLE OF SORT MODE OPERATION......... .. . . ..........8-6

7. BIN DRIVE MECHANISM .................................................. 8-8

8. BINS ................................................................................. 8-10

9. EXIT ROLLERS................................................................8-11

10. TIMING CHART..... ......................................................... 8-12

9. SORTER A557

1. SPECIFICATIONS..............................................................9-1

2. COMPONENT LAYOUT..................................................... 9-2

3. ELECTRICAL COMPONENT DESCRIPTIONS ................9-3

4. BASIC OPERATION .......................................................... 9-4

Rev. 7/95

A156/A160/A162 viii STM

5. EXIT ROLLER DRIVE MECHANISM................................. 9-5

6. BIN DRIVE MECHANISM .................................................. 9-6

7. MISFEED DETECTION .....................................................9-8

Rev. 7/95

STM ix A156/A160/A162

IMPORTANT SAFETY NOTICES

PREVENTION OF PHYSICAL INJURY

1. Before disassembling or assembling parts of the copier and peripherals, make sure that the copi er po wer cord is un pl u gg ed.

2. The wall outle t sho ul d be near th e cop i er an d ea si ly accessib l e.

3. Note that the drum heater and the optional anti-condensation heaters are supplied with electrical voltage even if the main 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 m ech an i cal ly dri ven components.

5. The inside and th e m et al pa r ts of the fusing unit become extre mel y ho t while the copier is operating. Be careful to avoid touching those components with your bare hands.

HEALTH SAFETY CONDITIONS

1 . 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 wit h wat er as fi r st 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.

CAUTION

2. The RAM board has a lithium battery which can explode if handled incorrectly. Replace only with the same type of RAM board. Do not recharge or burn this battery. Used RAM boards must be handled in accordance with local regulations.

STM a A156/A160/A162

SAFETY AND ECOLOGICAL NOTES FOR DISPOSAL

1 . Do not incinerate toner cartridges or us ed toner. Toner dust may ignite

suddenly when exposed to open flame.

2. Dispose of used to ne r , de vel o pe r , an d or g an i c pho to con du ctors 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 (from the main control boards) in

order to dispose of th em lat er , do no t sto r e m or e tha n 10 0 ba tt er i e s (f rom the main control boa r ds) pe r seale d bo x. Storing larger numbers or not sealing them apart may lead to chemical reactions an d heat build-up.

A156/A160/A162 b STM

TAB INDEX

TAB POSITION 1

TAB POSITION 2TAB POSITION 3TAB POSITION 4

TAB POSITION 5TAB POSITION 6

TAB POSITION 7TAB POSITION 8

OVERALL MACHINE INFORMATION

SORTER A557

Rev. 1/98

DETAILED SECTION DESCRIPTION

AUTO REVERSE DOCUMENT FEEDER A548

PAPER TRAY UNIT A550/A549

PAPER TRAY UNIT A553

SORTER STAPLER A554

SORTER STAPLER A555

SORTER A556

OVERALL MACHINE

INFORMATION

1. SPECIFICATIONS

Configuration: Desktop Copy Process: Dry electrostatic transfer system Originals: Sheet/Book Original Size: Maximum A3/11" x 17" Copy Paper Size: Maximum

A3/11" x17" (Paper trays)

Minimum

A5/8

1/2

" x 5

1/2

" sideways (Paper trays)

A4/11" x 8

1/2

" sideways (LCT)

A6/5

1/2

" x 8

1/2

" lengthwise (By-pass)

Duplex Copying: Maximum

A3/11" x 17"

Minimum

A5/8

1/2

" x 5

1/2

" (sideways)

Copy Paper Weight: Paper tray:

52 ~ 128 g/m2, 14 ~34 lb (A153, A155, and A1 56 copie r s) 64 ~ 90 g/m2, 17 ~ 24 lb (A157, A159, and A1 60 copie r s)

By-pass:

52 ~ 157 g/m2, 14 ~42 lb

LCT:

52 ~ 128 g/m2, 14 ~ 34 lb

Duplex copying:

64 ~ 105 g/m2, 17 ~ 24 lb

Reproduction Ratios: 4 Enlargement an d 6 Red uct i on

A4/A3 Version LT/DLT Version

Enlargement

200% 141% 122% 115%

200% 155% 129% 121%

Full size 100% 100%

Reduction

93% 82% 75% 71% 65% 50%

93% 85% 77% 74% 65% 50%

Power Source: 120V/60Hz:

More than 12 A (for North America)

Rev. 7/95

Overall Machine

Information

STM 1-1 A156/A160/A162

Power Consumption:

A153, and A156 copiers A157, and A160 copiers

Copier Only Full System Copier Only Full System

Maximum 1.45 KW 1.50 KW 1.45 KW 1.50 KW

Copying 1.00 KW 1.00 KW 0.80 KW 0.80 KW Warm-up 0.90 KW 0.92 KW 0.90 KW 0.92 KW Stand-by 0.16 KW 0.19 KW 0.15 KW 0.17 KW

Energy

Saver

1 0.15 KW 0.17 KW 0.14 KW 0.16 KW 2 0.13 KW 0.15 KW 0.12 KW 0.13 KW 3 0.12 KW 0.14 KW 0.09 KW 0.10 KW 4 0.11 KW 0.12 KW 0.07 KW 0.08 KW 5 0.09 KW 0.11 KW 0.05 KW 0.06 KW 6 0.07 KW 0.09 KW – –

Auto Off 0.02 KW 0.04 KW 0.02 KW 0.04 KW

NOTE:

1) Full System: Copier + ADF + Pap er Tr ay Unit + 20 Bin S/S

2) Energy Saver: See SP 1- 1 05 - 00 2

3) Auto Off: See SP5-305

A161 and A162 Copiers

Copier Only Full System

Maximum 1.45 KW 1.50 KW

Copying 0.64 KW 0.72 KW Warm-up 0.95 KW 0.97 KW Stand-by 0.15 KW 0.17 KW

Energy Saver

1 0.14 KW 0.16 KW 2 0.12 KW 0.13 KW 3 0.09 KW 0.10 KW 4 0.07 KW 0.08 KW 5 0.05 KW 0.06 KW

Auto Off 0.02 KW 0.04 KW

NOTE:

1) Full System: Copier + ADF + Pap er Tr ay Unit + 10 Bin S/S

2) Energy Saver: See SP 1- 1 05 - 00 2

3) Auto Off: See SP5-305

Noise Emission:

A153, and A156 copiers A157, and A160 copiers

Copier Only Full System* Copier Only Full System*

1. Sound Power Level

Copying 66 dB(A) 68 dB(A) 61 dB(A) 67 dB(A) (L

)

Warm-up 41 dB(A) 41 dB(A) 39 dB(A) 40 dB(A) (L

)

Stand-by 41 dB(A) 41 dB(A) 39 dB(A) 40 dB(A) (L

)

2. Sound Pressure Level at the operator position

Copying 58 dB(A) 57 dB(A) 54 dB(A) 56 dB(A) (L

)

Warm-up 33 dB(A) 27 dB(A) 32 dB(A) 27 dB(A) (L

)

Stand-by 33 dB(A) 27 dB(A) 32 dB(A) 27 dB(A) (L

)

NOTE:

The above measurements are to be made according to ISO 7779. * : Full System: Copier + ADF + Paper Tray Unit +10 Bin S/S.

Rev. 7/95

A156/A160/A162 1-2 STM

Dimensions:

Width Depth Height

A153 copier 1030 mm (40.6") 655 mm (25.8") 606 mm (23.9")

A157/A161 copier 900 mm (35.5") 655 mm (25.8") 606 mm (23.9")

A156 copiers 1258 mm (49.6") 655 mm (25.8") 606 mm (23.9")

A160/A162 copiers 1128 mm (44.5") 655 mm (25.8") 606 mm (23.9")

Measurement Conditions

1) With by-pass feed tabl e close d

2) With platen cover and copy tray attached

3) With LCT cover closed Weight:

Weight

FT5035 A153 copier About 70 kg (154.2 lb) FT5535 A156 copier About 82 kg (180.7 lb) FT4027 A157 copier About 67 kg (147.7 lb) FT4527 A160 copier About 80 kg (176.4 lb) FT4022 A161 copier About 67 kg (147.7 lb) FT4522 A162 copier About 80 kg (176.4 lb)

Zoom: From 50% to 200% in 1% steps Copying Speed (cop i es/ m inu te):

A4 sideways/

11" x 8

1/2

A3/11" x 17" B4/8

1/2

" x 14"

A153, and A156

copiers

35 20/19 22

A157, and A160

copiers

27 15/14 17

A161, and A162

copiers

22 12 -

Warm-Up Time A153, and A156 copiers:

Less than 110 seconds (20°C)

A157, and A160 copiers:

Less than 80 seconds (20°C)

A161 and A162 copier s:

Less than 60 seconds (20°C)

First Copy Time:

Paper Feed Station

A4/11" x 8

1/2

" (sideways)

A153, and A156

copiers

A157, and A160

copiers

A161, and A162

copiers

1st Tray

5.2 s (except for A156)

5.9 s (except for A160)

5.9 s (except for A162)

2nd Tray 5.7 s 6.6 s 6.6 s

By-pass 4.8 s 5.6 s 5.6 s

LCT 5.0 s 5.9 s 5.9 s

Note:

In A156, A160 and A161 copiers, the 2nd tray in the above table is

called the 1st tray (see Inst allation - Paper Feed Station Definitio n).

Rev. 7/95

Overall Machine

Information

STM 1-3 A156/A160/A162

Copy Number Input: Ten-key pad, 1 to 999 (count up or count down) Manual Image Density

Selection:

7 steps

Automatic Reset: 1 minute is the standard setting; it can be

changed to a maximum of 999 seconds or no auto reset by SP mode.

Copy Paper Capacity:

Paper Tray By-pass Feed LCT

A153 copier About 500 sheets x2 About 40 sheets – A156 copier About 500 sheets x1 About 40 sheets About 1000 sheets A157 copier About 250 sheets x2 About 40 sheets – A160 copier About 250 sheets x1 About 40 sheets About 1000 sheets

A161copier About 250 sheets x2 About 40 sheets –

A162 copier About 250 sheets x1 About 40 sheets About 1000 sheets

Duplex Tray Capacity [A156/A160/A162]:

50 sheets (30 sheets for A3/11"x17" 81 ~ 105g/m2, 21.5 ~ 27.9 lb paper)

Toner Replenishment: Cartridge exchange (415 g/cartridge) Toner Yield: 17K Copies/cartridge Developer Replenishment: Type 1 (1kg bag)

Developer Yield: A153/A156 @ 120K copies

A157/A160 @ 100K copies A161/A162 @ 100K copies

Optional Equi p m en t: • Platen cover

• Document feeder

• Paper tray unit with tw o pa pe r tr ays

•

Paper tray unit with thr e e pa pe r tr ays

•

10 bin micro sorter

•

20 bin mini sorter

• 10 bin sorter stapler

• 20 bin sorter stapler (Not used with A161 and A1 62)

•

Sorter adapter (required when installing 20 bin mini sorter, 10 bin sorter stapler, or 20 bin sorter stapler for A157, A160, A161, and A162 copiers)

•

Key counter

•

Tray heater

•

Optical anti-condensation heater

•

Original length sensor for 11" x 15" size paper (only for LT/DLT version)

•

ADS sensor for par ticu lar types of r ed orig ina l

•

Zoom (10 Key) Function Decal *

•

Margin Adjustment Function Decal *

Rev. 7/95

* Not used on FT4022/4522 (A161/A162 copiers)

A156/A160/A162 1-4 STM

2. MACHINE CONFIGURATION

2.1 COPIER

Rev 7/95

Overall Machine

Information

STM 1-5 A156/A160/A162

2.2 OPTIONAL EQUIPMENT

Only available on models FT5535, FT4527 and FT4522

** Not for use on FT4022/4522 (A161/A162) copiers.

Rev 7/95

A156/A160/A162 1-6 STM

3. MECHANICAL COMPONENT LAYOUT

– A156 copier –

NOTE:

The A153 copier is the same as the A156 copier except that the A153 does not hav e a duplex tray or an LCT.

28 27 26

24 23

1098

Overall Machine

Information

STM 1-7 A156/A160/A162

– A160/A162 copier –

NOTE:

The A157/A161 copiers are the same as the A160/A162 copiers except that the A157 and A161 do not have a duplex tray or an LCT.

Rev. 7/95

1098

A156/A160/A162 1-8 STM

Rev. 7/95

1. 3rd Mirror

2. 2nd Mirror

3. 1st Mirror

4. Exposure Lamp

5. Lens

6. Quenching Lam p

7. Drum Cleaning Blade

8. Drum Charge Roller

9. 6th Mirror

10. OPC Drum

11. Erase Lamp

12. 4th Mirror

13. 5th Mirror

14. Toner Supply Unit

15. Pre-transfer La m p

16. Development Unit

17. Registration Rollers

18. Feed Roller

19. Pick-up Roller

20. Separation Roller

21. Large Capacity Tray

22. Vertical Transport Rollers

23. Paper Feed Roller The roller for A153/A156 copiers is different from that for A157/160/161/162 copiers.

24. Friction Pad

25. Duplex Friction Roller

26. Duplex Feed Roller

27. Jogger Fence

28. Transfer Belt

29. Transfer Belt Cleaning Blade

30. Lower Paper Tray

31. End Fence

32. Entrance Rollers

33. Pick-off Pawls

34. Pressure Roller

35. Hot Roller

36. Junction Gate

37. Hot Roller Strippers

38. Transport Fan

Overall Machine

Information

STM 1-9 A156/A160/A162

4. PAPER PATH

4.1 NORMAL COPYING

– A156 copier –

–A160/A162 copier –

Rev. 7/95

A156/A160/A162 1-10 STM

4.2 DUPLEX COPYING

– A156 copier –

– A160/A162 copier –

Rev. 7/95

Overall Machine

Information

STM 1-11 A156/A160/A162

5. ELECTRICAL COMPONENT DESCRIPTIONS

Refer to the electrical component layout and the point to point diagram on the waterproof paper in the pocket for symbols and index numbers.

Symbol

Index

No.

Description Note

Printed Circuit Boards

PCB1 14

Main Control Controls all copier functions both directly or

through other control boards.

PCB2 12

AC Drive Provides ac power to the exposure lamp and

fusing lamps. PCB3 11 DC Power Supply Provides dc power. PCB4 96 Main Motor Control Controls the rotation of the main motor.

PCB5 1

CB High Voltage Supply

Supplies high voltage to the drum charge

roller and development roller. PCB6 55 T High Voltage Supply Supplies high voltage to the transfer belt.

PCB7 3

Operation Panel Controls the LED matrix, and monitors the

key matrix. PCB8 8

Noise Filter (220 ~ 240 V machines only)

Removes electrical noise.

PCB9 63

Duplex Control (Duplex machines only)

Controls the operation of the duplex tray.

PCB10 6

Liquid Crystal Display (A156 machines only)

Controls the guidance display and displays

guidance for machine operation.

PCB11 102

LCT Interface (LCT machines only)

Interfaces the LCT control signal between

the main board and the LCT.

Motors

M1 88 Main Drives the main unit components. M2 79

Toner Bottle Drive Rotates the toner bottle to supply toner to

the toner supply unit.

M3 97

Upper Tray Lift (A153 machines only)

Raises the bottom plate in the upper paper

tray.

M4 86

Lower Tray Lift (A153/A156 machines only)

Raises the bottom plate in the lower paper

tray.

M5 99

LCT Lift (LCT machines only)

Lifts up and lowers the LCT bottom plate.

M6 94 Optics Cooling Fan 1 Removes heat from the optics unit.

M7 95

Optics Cooling Fan 2 (A153/A156 machines only)

Removes heat from the optics unit.

M8 89 Exhaust Fan 1 Re m oves the h eat fro m around the fu s ing uni t .

M9 90

Exhaust Fan 2 (A153/A156 machines only)

Removes the heat from around the fusing

unit.

M10 92 Scanner Drive Dri v e s t h e 1 s t and 2nd scanners (dc stepper motor). M11 78 3rd Scanner Drive Drives the 3rd scanner (dc stepper motor). M12 87 Lens Vertical Drive Shifts the lens vertical position. M13 77 Lens Horizontal Drive Shifts the lens horizontal position.

M14 58

Duplex Feed (Duplex machines only)

Drives the feed roller and moves the bottom

plate up and down.

M15 61

End Fence Jogger (Duplex machines only)

Drives the end fence jogger to square the

paper stack.

A156/A160/A162 1-12 STM

Symbol

Index

No.

Description Note

M16 60

Side Fence Jogger (Duplex machines only)

Drives the side fence jogger to square the

paper stack.

Sensors

S1 27

By-pass Feed Paper Width

Informs the CPU what width paper is in the

by-pass feed table.

S2 31

By-pass Feed Paper End

Informs the CPU that there is no paper in

the by-pass tray.

S3 51

Upper Tray Paper End (Non-duplex machines only)

Informs the CPU when the upper paper tray

runs out of paper.

S4 107

Upper Relay Detects the leading edge of paper from the

upper tray to determine the stop timing of

the upper paper feed clutch,

and detects

misfeeds.

S5 29

Upper Tray Upper Li mit (A153 machines only)

Detects the height of the paper stack in the

upper paper tray to stop the upper tray lift motor.

S6 52

Lower Tray Paper End

Informs the CPU when the lower paper tray

runs out of paper.

S7 106

Lower Relay Detects the leading edge of paper from the

lower paper tray to determine the stop timing

of the lower paper feed clutch,

and detects

misfeeds.

S8 30

Lower Tray Upper Limit (A153/A156 machines only)

Detects the height of the paper stack in the

lower paper tray to stop the lower tray lift motor.

S9 100

LCT Lower Limit (LCT machines only)

Sends a signal to the CPU to stop lowering

the LCT bottom plate.

S10 26

LCT Paper End (LCT machines only)

Informs the CPU when the LCT runs out of

paper.

S11 28

LCT Upper Limit (LCT machines only)

Sends a signal to the CPU to stop lifting the

LCT bottom plate.

S12 28

Registration Detects the leading edge of the copy paper

to determine the stop timing of the paper

feed clutch,

and detects misfeeds.

S13 50

Image Density (ID)

Detects the density of various patterns on

the drum during process control.

S14 53

Toner Density (TD)

Detects the amount of toner inside the

development unit.

S15 39

Lens Horizontal HP Informs the CPU that the lens is at the

horizontal home position.

S16 20

Lens Vertical HP Informs the CPU that the lens is at the

full-size position.

S17 15

Scanner HP Informs the CPU when the 1st and 2nd

scanners are at the home position.

S18 24

3rd Scanner HP Informs the CPU when the 3rd scanner is at

the home position.

S19 21

Original Length-2 Detects the length of the original. This is one

of the APS (Auto Paper Select) sensors.

S20 45 Fusing Exit

Detects misfeeds.

S21 16

Platen Cover Informs the CPU whether the platen cover is

up or down (related to APS/ARE functions).

ARE: Auto Reduce and Enlarge

S22 54

Toner End Instructs the CPU to add toner to the toner

supply unit, and detects toner end conditions.

Rev. 7/95

Overall Machine

Information

STM 1-13 A156/A160/A162

Symbol

Index

No.

Description Note

S23 43

Auto Response (Not used on A161/A162 copiers)

Returns the operation panel display and

exits from the energy saver mode.

S24 23

Transfer Belt ContactHPInforms the CPU of the current position of

both the transfer belt unit and the drum

charge roller unit.

S25 13

Auto Image Density (ADS Sensor)

Detects the background density of each

original in ADS mode.

S26 44

Original Width Detects the width of the original. This is one

of the APS (Auto Paper Select) sensors.

S27 19

Original Length-1 Detects the length of the original. This is one

of the APS (Auto Paper Select) sensors.

S28 56

Duplex Paper End (Duplex machines only)

Detects paper in the duplex tray.

S29 57

Duplex Turn (Duplex machines only)

Detects the trailing edge of the copy paper to

determine the jogging timing, and detects misfeeds.

S30 62

Duplex Entrance (Duplex machines only)

Detects misfeeds.

S31 59

Side Fence Jogger HP (Duplex machines only)

Detects the home position of the duplex side

fence jogger.

S32 64

End Fence Jogger HP (Duplex machines only)

Detects the home position of the duplex end

fence jogger.

S33 22

Original Length (Option for N. American models)

Detects original length for 11" x 15" paper.

Switches

SW1 33

By-pass Feed Table Detects whether the by-pass feed table is

open or closed.

SW2 36

Upper Tray (Non-duplex machines only)

Detects whether the upper paper tray is in

place or not.

SW3 35

Lower Tray Detects whether the lower paper tray is in

place or not.

SW4 104

Tray Down (LCT machines only)

Sends a signal to the CPU to lower the LCT

bottom plate.

SW5 25

Upper Tray Paper Size (Non-duplex machines only)

Determines what size of paper is in the

upper paper tray.

SW6 34

Lower Tray Paper Size

Determines what size of paper is in the

lower paper tray.

SW7 32

Vertical Guide Set (Non-LCT machines only)

Detects whether the vertical guide is open or not.

SW8 105

LCT Cover-1 (LCT machines only)

Detects whether the L CT cover is op en o r n ot.

SW9 103

LCT Cover-2 (LCT machines only)

Cuts the dc power line of the LCT lift motor.

SW10 42 Main Supplies power to the copier. SW11 41

Front Cover Safety Detects whether the front door is open and

via relays cuts the ac power.

SW12 48

Exit Cover Safety (A157/A160 machines only)

Detects whether the exit cover is open or not.

Rev. 7/95

A156/A160/A162 1-14 STM

Symbol

Index

No.

Description Note

Magnetic Clutches

CL1 72

Toner Supply Turns the toner supply roller to supply toner

to the development unit.

CL2 71 Development Drives the development roller.

CL3 93

Transfer Belt Contact (1/3 Turn Clutch)

Controls the touch and release movement of

both the transfer belt unit and the drum

charge roller unit.

CL4 73 Registration Drives the registration rollers. CL5 74

By-pass Feed Starts paper feed from the by-pass feed

table or LCT.

CL6 76 Relay Drives the relay rollers.

CL7 84

Upper Paper Feed (Non-duplex machines only)

Starts paper feed from the upper paper tray.

CL8 85

Lower Paper Feed Starts paper feed from the lower paper tray.

Solenoids

SOL1 75

LCT machines: LCT/By-Pass Pick-up Solenoid Non-LCT machines: By-pass Pick-up Solenoid

Picks paper up from the by-pass feed table.

When paper is fed from the LCT, this

solenoid assists SOL3.

SOL2 91

Junction Gate (Duplex machines only)

Moves the junction gate to direct copies to

the duplex tray or to the paper exit.

SOL3 98

LCT Pick-up (LCT machines only)

Picks up paper from the LCT.

SOL4 80

Upper Tray Pick-up (A153/ machines only)

Controls the up/down movement of the

pick-up roller in the upper paper tray.

SOL5 82

Lower Tray Pick-up (A153/A156 machines only)

Controls the up/down movement of the

pick-up roller in the lower paper tray.

SOL6 81

Upper Tray Separation (A153/ machines only)

Controls the up-down movement of the

separation roller in the upper paper tray feed

station.

SOL7 83

Lower Tray Separation (A153/A156 machines only)

Controls the up-down movement of the

separation roller in the lower paper tray feed

station.

Lamps

L1 17

Exposure Applies high intensity light to the original for

exposure.

L2 65

Main Fusing Provides heat to the central area of the hot

roller.

L3 66 Secondary Fusing Provides heat to both ends of the hot roller.

L4 4

Pre-transfer Reduces the charge remaining on the drum

surface before transfer.

L5 5

Quenching Neutralizes any charge remaining on the

drum surface after cleaning.

Overall Machine

Information

STM 1-15 A156/A160/A162

Symbol

Index

No.

Description Note

L6 2

Erase After exposure, this eliminates the charge on

areas of the drum that will not be used for

the image.

Heaters

H1 38

Drum Turns on when the main switch is off to keep

the temperature around the drum charge

roller at a certain level. Also prevents

moisture from forming around the drum.

H2 46

Optics Anti-condensation (option)

Turns on when the main switch is off to

prevent moisture from forming on the optics.

H3 37

Lower Tray (option)

Turns on when the main switch is off to keep

paper dry in the lower paper tray.

Thermistors

TH1 69

Main Fusing Monitors the temperature at the central area

of the hot roller.

TH2 70

Secondary Fusing Monitors the temperature at the ends of the

hot roller.

TH3 47 Optics Monitors the temperature of the optics cavity. TH4 49

Drum Charge Monitors the temperature of the drum charge

roller.

Thermofuses

TF1 68

Main Fusing Provides back-up overheat protection in the

fusing unit.

TF2 67

Secondary Fusing Provides back-up overheat protection in the

fusing unit.

TF3 18

Exposure Lamp Opens the exposure lamp circuit if the 1st

scanner overheats.

Counters

CO1 40

Total Keeps track of the total number of copies

made.

CO2 N/A

Key (option)

Used for control of authorized use. The

copier will not operate until it is installed.

Others

CB1 9

Circuit Breaker (220 ~ 240V machines only)

Provides back-up high current protection for

electrical components.

CC1 10

Choke Coil (220 ~ 240V machines only)

Removes high frequency current.

TR1 7

Transformer (220 ~ 240V machines only)

Steps down the wall voltage to 100 Vac.

Rev. 7/95

A156/A160/A162 1-16 STM

6. DRIVE LAYOUT

6.1 ALL MODELS

1. Drum Drive Pu lley

2. Drum Cha rge Roller Drive Gear

3. Transfer Belt Contact Clutch Gear

4. Scanner Drive Motor

5. Sca nner Drive Pulley

6. Transfer Belt Dr i ve Ge ar

7. Fusing Unit Drive Gear

8. Main Motor

9. Main Pulley

10. Registration C lutch Gear

11. By-pass Feed Clutch Gear

12. Development Drive Clutch Gear

13. Toner Supply Clutch Gear

Overall Machine

Information

STM 1-17 A156/A160/A162

6.2 A153/A156

1. Upper Paper Feed Clutch Gear (A153 only)

2. Lower Paper Feed Clutch Gear

3. Relay Clutch Gear

6.3 A157/A160/A161/A162

1. Upper Paper Feed Clutch Gear (A157 and A161 only)

2. Lower Paper Feed Clutch Gear

3. Relay Clutch Gear

Rev. 7/95

A156/A160/A162 1-18 STM

DETAILED DESCRIPTIONS

1. PROCESS CONTROL

1.1 OVERVIEW

1.1.1 Copy Process around the Drum

1. DRUM CHARGE

In the dark, the dru m char g e r oll e r gives a un i fo r m neg at i ve cha rge to the organic photo-co nd uctive (OPC) drum. The charge re m ain s on th e sur f ace of the drum because th e OP C la yer ha s a high el ect r i cal resi st an ce i n th e da r k. The amount of negative charge on the drum is proportional to the negative voltage applied to the drum charge roller.

9. QUENCHING

2. EXPOSURE

3. ERASE

5. PRE-TRANSFER LAMP

6. IMAGE TRANSFER

7. PAPER SEPARATION

8. CLEANING

PICK-OFF PAWLS

1. DRUM CHARGE

ID SENSOR

TRANSFER BELT

4. DEVELOPMENT

Fig. 1 Copy Process Around the Drum

Detailed

Descriptions

STM 2-1 A156/A160/A162

2. EXPOSURE

An image of the original is reflected onto the OPC drum surface via the optics assembly. The charge on the drum surface is dissipated in direct proportion to th e i nt en si ty of t he refl e cte d l i gh t, thu s prod uci n g an el ect r i cal latent image on the drum surface .

The amount of remaining charge as a latent image on the drum de pe nd s on the exposure lamp intensity, which is controlled by the exposure lamp voltage.

3. ERASE

The erase lamp illuminates the areas of the charged drum surface that will not be used for the copy image. The resistance of the drum in the illuminated areas drops and the charge on those areas dissipates.

4. DEVELOPMENT

As a result of the development potential (the difference of charged voltage between the drum and the toner), toner is attracted to the areas of the drum where the negative charge is greater than that of the toner, and the latent image is developed.

The development bi as voltage applied to the developm en t r oll e r shaf t controls two things:

1) The threshold level for whether toner is attracted to the drum or whether it remains on the development roller.

2) The amount of toner to be attracted to the drum.

The higher the negat i ve de velo pm e nt bias voltage is, the less toner is attracted to the drum surface.

5. PRE-TRANSFER LAMP (PTL)

The PTL illuminates the drum to remove almost all the negative charge from the exposed areas of the dr um. This prevents the toner particles from being reattracted to the drum surface during paper separation and makes paper separation easier.

A156/A160/A162 2-2 STM

6. IMAGE TRANSFER

Paper is fed to the area between the drum surface and the transfer belt at the proper time so as to align the copy paper and the developed image on the drum surface. Then, the transfer bias roller applies a strong negative charge to the reverse side of the copy pa pe r thro ug h th e tr a nsf er be l t. This negative charge produces an electrical force which pulls the toner particles from the drum surface on to the copy paper. At the same ti me, the copy paper is electrically attracted to the transfer belt.

7. PAPER SEPARATION

Paper separates fr om th e OP C drum as a r esu lt of the electrical attracti o n between the paper and the transfer belt. The pick-off pawls help s eparate the paper from the drum.

8. CLEANING

The cleaning blade removes toner remaining on the drum after the image is transferred to th e pa pe r .

9. QUENCHING

Light from the quenching lamp electrically neutralizes the ch arge on the drum surface.

Detailed

Descriptions

STM 2-3 A156/A160/A162

1.1.2 Factors Affecting Process Control

In this copier, the following items are controlled during the copy process to maintain good copy quality:

•

Exposure lamp voltage

•

Drum charge roller voltage

•

Development bias voltage

•

Toner supply

The machine controls the items listed above by monitoring the following electrical components:

•

Operation panel (manual ID selection and reproduction ratio)

•

ADS sensor

•

TD sensor

•

ID sensor

•

Drum charge thermistor

•

Paper size detectors

•

RAM board (drum rotation time, SP mode data, and paper size data)

Fig. 2 Process Control

Rev. 7/95

A156/A160/A162 2-4 STM

1.1.3 Process Control Procedures

This section outlines how the ma chin e con tr o ls the copy pr o cess ba sed on the inputs from various sensors.

1.1.3.1 Copy Image Control

This is how the machine adjusts copy processes based on settings input at the operation panel.

- Manual ID Correction -

If the user inputs the i m ag e de nsi t y ma nu all y, the machine adjusts the exposure lamp voltage and the development bias to achieve the selected image density.

- Reproduction Ratio Correction -

If the user selects a 116% or greater enlargement ratio or a 50% reduction ratio, the machine corrects the developmen t bia s to compen sat e fo r the loss in light intensity reaching the drum.

- ADS Pattern Detection and ADS Correction -

If the user selects Auto Image Density (ADS) mode, the machine monitors the output from the ADS sensor and adjusts the development bias to compensate for variations in ADS sensor response. This preve nt s dirty background.

Every 1,000 copies, the ma chine calibrates the ADS sensor out pu t by reading the white ADS pattern under the left scale of the exposure glass.

The ADS sensor must also be recalibrated:

• If the drum is changed

• If the ADS sensor is cleane d or cha ng ed

• If the exposure lamp or opt ics ar e clea ned or changed.

1.1.3.2 Image Density Control

This is how the machine cor r e cts th e con centration of toner in the devel o pe r based on readings from the ID (Image Density) and TD (Toner Density) sensors.

- VSP and VSG Detection/ID Correction -

The machine uses VSP and VSG readings by the ID sensor, along with readings from th e to ne r den s ity sen s or, t o dete r m ine if the ton er concentration in the de veloper is at the optimum level.

Rev. 6/95

Detailed

Descriptions

STM 2-5 A156/A160/A162

The amount of toner supplied to the VSP pattern must remain constant. To ensure this, the machine applies a correction to the development bias for VSP patterns when combined readings from the TD and ID sensors indicate that the carrier is aging. This correction is called "ID Correction".

- Toner Supply -

There are three toner supply modes.

Detect toner supply:

Toner supply varies with paper size, the latest TD sensor reading, and the l at est VSP and VSG readings by the ID sensor. For example, toner supply will be increased if the toner weight ratio in the developer is decreasing, or if the most recent VSP pattern was detected as being relatively light.

Fixed supply mode:

The toner supply remains constant, but can be

adjusted with an SP mode.

TD supply mode:

Toner supply varies with TD sensor output. For example, if the toner weight ratio has decr eased since TD sensor supply mode was selected, toner supply is increased.

1.1.3.3 Drum Potential Control

This is how the machine com p en sates for aging of the drum and the exposure lamp, and for the temperature around the drum charge roller.

- VR Pattern Detection and VR Correction -

As the drum gets older, the drum’s residual voltage gradually inc r eases due to electrical fatigue. Light from the exposure lamp will not dissipate the increased residual voltage effectively and dirty background will result.

Every 1,000 copies, par t of th e dr u m is de velo pe d w i th the VR pattern development bias . If the r e i s re sidu al vol t ag e on the dr um , thi s ar e a of the drum will attract some toner, making a VR pattern. The ID sensor respon se to this pattern is compa r ed wit h the response of the ID sensor to a bare ar e a of the drum. The higher the residual voltage on the drum is, the darker the VR pattern is. If the pattern is too dark, the drum will not be discharged sufficiently. As a result, the machine will increase the negative development bias to prevent dirty background. If it does, image density will drop. To prevent this, the machine will also increase the negative drum charge roller voltage.

(The VRP/VRG range to which the above mentioned bias and charge corrections are applie d m ay be shift ed to can cel th e effect of ID correction.)

VR correction data must be reset by SP mode (forced VR detection) if the drum is changed or if th e ID sen s or i s cle an ed or re pl a ced .

Rev. 6/95

A156/A160/A162 2-6 STM

- VL Pattern Detection and VL Correction -

This is how the machine adjusts the exposure lamp voltage to compensate for the effects of dr um w ea r , dir ty optics, and response of the drum to light.

Every 1,000 copies, an im ag e of the VL pattern under the left scal e bra cket is made on the drum. The machine compares the respons e of the ID sensor to this image with the re spo nse to a ba r e ar e a of the dr um .

The exposure lamp voltage is ad just ed if the r e ha ve be en signi f i can t changes from the measurements made from when a new drum or lamp was installed.

(The VLP/VLG range to which the above mentioned lamp voltage adjustment is applied may be shifted to can cel th e ef fe ct of ID corr ect ion .)

Initial VLP/VLG detection must be done by SP m od e i f a ne w dr um is insta l l ed or if the exposure lamp is cleaned or replaced.

- T/H Correction -

The efficiency of the tran sfe r of cha r ge from th e dr u m char g e roll e r to th e drum varies with the temperature near the drum charge roller. Also, the drum potential after charging v aries with the accumulated rotation time of the drum.

A thermistor measures the temperature near the drum charge roller, and the CPU keeps track of how long the drum has been rotating.

The machine adjusts the drum charge roller voltage depending on the temperature an d accu m ul a te d r ot at i on ti me.

This section has provided an overview of all the process control procedures done by the machine. The next few pages will explain each of these in more detail. At the end, there will be a summary.

Detailed

Descriptions

STM 2-7 A156/A160/A162

1.2 COPY IMAGE CONTROL

Copy image control adjusts the development bias and exp osu re l amp voltage to take account of the reproduction ratio an d i m ag e de nsi t y. The image density is either selected by the user or detected automatically.

1.2.1 Manual ID Cor rection

If the user selects the image density manually, the selected manual ID level affects the exposure la m p volt age and the development bias as fo ll ows .

- Exposure Lamp Voltage -

As the ID level increases from 1 to 7, the exposure lamp voltage is increased as shown in the following table.

Table 1. Exposure lamp voltage control by manual ID level

ID Level Lamp Voltage

1 Vexp –4.0 V 2 Vexp –3.0 V 3 Vexp –1.5 V 4

Vexp ±0.0 V 5 Vexp +1.5 V 6 Vexp +4.0 V 7 Vexp +6.0 V

Vexp = Lamp voltage selected with SP4-001. It can be be tween 50 and 75 V. It is factory set, and varies from copier to copier.

- Development Bias -

The greater the nega ti ve vol ta ge , th e pa l er the image on the drum. However , the development bias is adjusted only at the extreme light and dark ends of the manual ID range.

Table 2. Development bias control by manual ID level

ID Level Development Bias

1 +80 V 2

0 V

7 SP2-201-002 (see below)

Note:

The base development bi as voltage is -240 Volts.

A156/A160/A162 2-8 STM

For ID Level 7 (lightest copies), there are four possible development bias correction settings that can be selected with SP2-201-002, as shown below.

Table 3. Lightest ID level development bias (ID Level 7)

SP2-201-002 Setting Density

Dev. Bias

Correction Voltage

1 (Factory Setting) Normal –40 V

2 Dark

0 V 3 Lighter –80 V 4 Lightest –120 V

In summary, the develo pme nt bi as at vari ou s ID level set ti n gs is show n below.

1.2.2 Reproduction Ratio Correction

At reproduction ratios of 50% and 116% or greater, the intensit y of light reaching the drum from the original drops significantly, which could cause copies to become un derexposed (too dark).

To compensate for this, a development bias correction voltage is applied as shown in Table 4. This correction increases the development bias voltage, restoring the copy image de nsi t y to no rm al.

Table 4. Reproduction ratio correction

Reproduction

Ratio (%)

Development Bias

Correction Voltage

181 ~ 200 –100 V 161 ~ 180 –80 V 142 ~ 160 –60 V 123 ~ 141 –40 V 116 ~ 122 –20 V 51 ~ 115

0 V

50 –30 V

–280

–240

–320

1765432

ID Level

Development Bias Voltage

–320 (Lighter)

–240 (Darker)

–280 (Normal)

–360 (Lightest)

SP2-201-002 for ID Level 7

–160

Detailed

Descriptions

STM 2-9 A156/A160/A162

1.2.3 ADS Correction

If the user selects Auto Image Density (ADS) mode, the output of the ADS sensor is used to correct the development bias; the exposure lamp voltage is kept at the setting fo r ID level 4 an d is not adju sted.

In ADS mode, the ADS sensor [A] det ect s the or igi n al ba ckgr o un d density. To prevent dirty background from appearing on copies, the CPU corrects the development bias voltage for the original. To do this, it compares the ADS sensor output from th e original [V

ADS

(original)] with a stored reference value

ADS

(pattern)] that wa s take n ea r l ier fr o m t he ADS sen s or pattern. The

correction is shown in table 5, and is applied every copy. Table 5. ADS data correction

ADS Density SP5-106

Development Bias Correction Voltage

Setting

Copy Density

0 Darker 816 x (AR – 0.79) 1 Normal 816 x (AR – 0.85) 2 Lighter 816 x (AR – 0.95)

Where AR (ADS Ratio) = V

ADS

(original)/V

ADS

(pattern)

Note that there are three possible corrections. The default setting is 1 (normal). Howe ver , for exa mpl e , i f th e use r re qu ir es cop i es to be dar ker when using ADS mode, a technician can set SP5-106 to 0.

ADS

(pattern) is checked every 1,000 copies. (See proce ss control che cks at every 1,000 copies on p2-29.) It is kept at 2.7±0.1 volts by a gain adjustment.

See the "Optics - Automatic Image Density Control System (ADS)" section for more details on how th e ADS sensor measures the background an d on how [V

ADS

(pattern)] is corrected every 1,000 copies.

ADS pattern

[A]

Fig. 3 ADS pattern

A156/A160/A162 2-10 STM

1.3 IMAGE DENSITY CONTROL

1.3.1 Overview

The machine controls the toner supply mechanism using the toner density sensor (TD sensor) and the image density sensor (ID sensor).

Readings from the TD sensor are used to keep the toner concentration in the developer at a constant level. However, the image on the OPC drum varies due to the variation in toner chargeability, which is influenced by the environment, eve n if th e to ne r conce nt r at i on is con sta nt . Because of this, readings from th e ID sensor are used to change the toner conce nt r ation to keep the image density on the OPC drum constant.

1.3.2 VSP and V

Detection

The ID sensor [A] (below the drum cleaning section) che cks the following voltages.

• V

: the ID sensor output when checking the erased drum surface.

•

VSP: the ID sensor output when checking the Vsp pattern image.

In this way, the reflectivity of both the erased drum surface and the pattern on the drum are checked. This compensates fo r any variatio ns in ligh t intensity from th e LE D compo ne nt of the sensor or the reflectivity of t he drum .

The VSP pattern [B] is made on the OPC drum by the drum charge roller [C] and the erase lamp [D].

65 mm

35 mm

[B]

[C]

[A]

[D]

Dev. bias

Drum

LED

Detailed

Descriptions

STM 2-11 A156/A160/A162

• V

is measured at the start of every copy run.

• V

is detected at the end of a cop y ru n if 10 or mo re cop i es ha ve be en made since VSP was last measured. The transfer be lt m ust be rele ase d to measure VSP, so it cannot be checked during a copy run.

1.3.3 ID Correction for the VSP Pattern Background

Developer consists of carrier particles (ferrite and resin) and toner particles (resin and carbon). The positive triboelect ric charg e on the ton er is caused by friction between the carrier and toner particles. However, the chargeability of carrier decreases with time. Therefore, if the toner weight ratio in the developer is the same, the amount of positive triboelectric charge for one particle of toner decreases. This is because the number of toner particles which surround one carrier particle is the same, but the chargeability of one particle of carrier is less than before.

If the development potential, that is, the difference of voltage between the development roller and the drum for the VSP pattern is the same, more toner particles are attracted to the VSP pattern, because on e pa r ti cl e of to ne r has less positive charge than before. (More toner particles are required to balance the charge of the VSP pattern.)

If the ID sensor were to check the VSP pattern’s reflectivity under this condition, the VSP pattern would be darker than before. The CPU would then incorrectly conclude that the toner weight ratio in the develo per is too high even though the ratio act ua ll y rem ain s the same. The C PU wou l d th en decrease the toner clutch on time, leading to a low per cen ta ge of to ne r in t he developer by weight as the copy count rises.

If uncontrolled, this would cause some side effects, such as low image density or developer adhering to the copy. To prevent these side effects, ID correction is done when the VSP pattern is made.

12345678 9101112

14 15

VSP Detection

Detection

1st Series of Copies (8 copies)

3rd Series of Copies (17 copies)

2nd Series of Copies (5 copies)

Detection

A156/A160/A162 2-12 STM

The idea behind ID corr e ctio n i s t o can cel th e ef fe ct on the VSP pattern of the decrease in the chargability of carrier with time. ID correction is done by changing the develo pm e nt bi as fo r t he VSP pattern so that it has the same darkness even though the chargeability of the carrier has changed.

ID Correction Method

The machine determines whe th er th e de vel o pme nt bi as ne ed s adju stin g by monitoring the de nsi t y of th e to ne r /ca r ri er m i xtu re i n th e de velo pm e nt unit. When the toner weight rati o in the developer changes, the voltage output by the TD sensor changes accordingly. The smaller the toner weight ratio in the developer is, the great er th e TD sensor out pu t is, as sho w n in th e di a gra m below.

When new developer with the standard concentration (2.0% by weight, 20 g of toner in 1,000 g of developer) is installed, the TD sensor initial setting must be done with SP mode 2-214. This sets the sensor output to 2.5 ± 0.1 V.

As shown earlier, the chargeability of carrier in the developer decreases with the copy count. If no correction is done, the CPU tries to decrease the toner weight ratio in th e de vel o pe r . So this eve nt ua l ly cause s the re ad i ng fr om th e TD sensor to exceed its maximum acceptable value (initial value + 1.0 V).

If the corrected TD sensor output V

TREF

exceeds the upper limit over 100

times continuously, devel op ment bias for the VSP pattern is corrected. V

TREF

is the current TD sensor output with a correction factor included that is based on the VSP/VSG ratio from the ID sensor (see VSP and VSG Detection) calculated every 10 copies or so (see Toner Supply Control - Detect Supply Mode for more about V

TREF

The first time this happens, the correction is -40 V. If the upper limit is exceeded 100 consecutive times again later, an extra -40 V correction is applied (see the following table). There should be no need for further steps, because the toner proportion by weight will stabilize before this.

Rev. 6/95

Detailed

Descriptions

STM 2-13 A156/A160/A162

Table 6. ID correction

Step Development Bias Correction for the VSP Pattern

Initial 0 V

1st –40 V

2nd –80 V

If no correction is ap pli e d, the charge on the drum for the VSP pattern is –600 V, and the development bias for the VSP pattern is –300 V. So the r e is a difference of 300 V between the development roller and the drum for the VSP pattern.

When the ID correction is applied, the voltage difference is reduced. For example, if a –40 V ID correction is applied, the difference in voltage is:

Before ID Correction: –300 – (–600) = 300 V After ID Correction: –300

– 40

– (–600) = 260 V

As a result, the effect of the change in chargeability of the carrier particles is canceled. The darknes s of the VSP pattern returns to normal.

1.3.4 Toner Supply Control During Copying

There are three modes for controlling the toner supply.

• Detect supply mode

• Fixed supply mode

• TD sensor supply mode

The mode can be selected with SP2-208-001. The factory setting is detect supply mode.

Toner clutch on time is calculated by the following formula.

Toner CL on time [ms] =

S x AT x TSC

⁄

100

(Formula 1)

where: S = Copy paper size [cm2]

AT = Amount of ton er de veloped on the latent image per un i t area

= 0.7 [mg/cm2] (constant) TSC = Toner supply coefficient [%] TS = Amount of toner supplied per unit of time

= 0.183 [mg/ms] (f or A1 53 , A1 55 , an d A1 56 copi e r s)

= 0.133 [mg/ms] (f or A1 57 , A1 59 , an d A1 60 copi e r s)

AT and TS are constant, and S depends only on paper size, but TSC is determined in different ways depending on which toner supply mode is in use.

A156/A160/A162 2-14 STM

Determination of TSC

TSC is an estimate of the proportion of black area in the image that is made by the machine.

(1) Detect Supply Mode

In detect supply mode, TSC is determined from outputs from both the TD and ID sensors, in conjunction with the toner supply ratio that has been selected for this mode.

- Toner Supply Ratio -

This is selected with SP2-22 2. The set ti n gs are 1 (7%) , 2 ( 15% ), 3 ( 30 %), or 4 (60%). The default is 15%.

- TD and ID Sensor Outputs -

The machine calculates a value fo r VT-V

TREF.

•

VT: Current TD sensor output

• V

TREF

: TD sensor output at the lat est VSP detection corrected for ID sensor output (VSP/VSG); this is calculated every 10 or so copies (see VSP/V

Detection for more on VSP and VSG)

TREF

is determined as follows.

TREF

= VTP + ∆ V

REF (Formula 2)

•

= TD sensor output at VSP detection

•

∆

REF

= Correction factor based on VSP/V

(from the ID sensor

output), deter mi ne d by th e fo l l owi n g ta bl e .

Table 7.

SP/VSG

∆ V

REF

[V]

~ 0.075 +4 x 0.0196

0.076 ~ 0.090 +2 x 0.0196

0.091 ~ 0.105

0.106 ~ 0.125 –2 x 0.0196

0.126 ~ 0.160 –4 x 0.0196

0.161 ~ 0.205 –6 x 0.0196

0.206 ~ 0.500 –8 x 0.0196

0.501 ~ The previous V

TREF

TSC [%] is then determined from VT-V

TREF

and the toner supply ratio, as

shown by table 8.

VSP pattern darker

pattern

lighter

Detailed

Descriptions

STM 2-15 A156/A160/A162

Table 8. Toner Supply Coefficient (%)

(

T-VTREF)

/0.0196

Supply Ratio (SP Mode Setting)

7% 15% 30% 60%

~ 0 0 0 0 0 1 ~ 3 7153060 4 ~ 515304560 6 ~ 730456060 8 ~ 60 60 60 60

For example, if the toner supply ratio is 15% and (VT-V

TREF

)/0.0196 is 4.5, TSC is 30. This value is then used in the formula to determine the toner supply clutch on time given at the start of this discussion. (See formula 1.)

This all means that, if the ID sensor reading indicated that the most recent VSP pattern was relatively light, the toner supply clutch will stay on for longer. (If VSP/VSG is higher,

∆

REF

is smaller [Table 7]. This means that

TREF

is smaller [Formula 2], leading to a larger VT-V

TREF

. So, for a particular toner supply ratio, the TSC value will be higher [Table 8], so the clutch stays on for longer [Formula 1].)

(2) Fixed Supply Mode

TSC [%] is fixed. It is selected with SP mode 2-208-003 as shown below.

Table 9. Toner Supply Coefficient (%)

SP2-208-003 Value

1234

TSC [%] 2 4 6 11

NOTE:

Default = 6%

The machine automatically switches to fixed supply mode if the ID or TD sensor fail (see section 1.3.5.).

(3) TD Sensor Supply Mode

TSC [%] is determined as shown in Table 8 for detect supply mode. However, the toner supply ratio and VT – V

TREF

are both determined in

different ways. In particular, the ID sensor output is ignored.

- Toner Supply Ratio -

The supply ratio is selected wit h SP 2-2 08 - 00 2. The set ti n gs are 1 (7%) , 2 (15%), 3 (30%), or 4 (60%). The default is 15%.

- VT – V

TREF

•

TREF

= V

TREF

at the moment that TD sensor supply mode was selected.

•

VT = Current TD sensor output

A156/A160/A162 2-16 STM

1.3.5 Toner Supply in Abnormal Sensor Conditions

If any sensor errors occur under detect supply mode, toner supply mode is changed automat ical l y as sho w n be low .

Table 10.

Error Abnormal Condition

Fallback Toner

Supply Mode

Display on

Operation Panel

ID Sensor Adjustment Error

When ID sensor output cannot be adjusted to 4.0

0.2 V

Fixed Supply Mode None

Abnormal ID Sensor (V

)

If V

> 2.5 V during V

detection.

Fixed Supply Mode

None

Abnormal ID Sensor (V

)

If V

< 2.5 V during V

detection

Fixed Supply Mode

TD Sensor Adjustment Error

When TD sensor output cannot be adjusted to 2.5

0.1 V

Fixed Supply Mode

Manual ID level or ADS indicator blinks

TD Sensor (V

)

Measurement Error

If VT > 4.0 V or VT < 0.3 V during V

detection.

Fixed Supply Mode

Manual ID level or ADS indicator blinks

Drum Charge Thermistor Error

Temperature detected by the drum charge thermistor is below 0°C or above 60°C

Fixed Supply Mode None

Abnormal Drum Charge Thermistor Output

Temperature detected by the drum charge thermistor (T) is between 0 °C and 20°C

TD Sensor Supply Mode

None

NOTE:

No indication is displ aye d un de r the "ab no r mal dr u m charg e thermistor output" condition, because the machine soon recovers due to the heat inside the machine.

Detailed

Descriptions

STM 2-17 A156/A160/A162

1.4 DRUM POTENTIAL CONTROL

The characteristics of the drum vary with the temperature around the drum, and they change as the drum gets older. To take account of these and other related factors, this machine has the following three drum potential control routines.

• V

pattern correction

• V

pattern correction

• T/H correction

1.4.1 VR Pattern Correction

As the drum ages, the drum res idual voltage gradually increas es due to electrical fatigue (see the upper left chart). In other words, as the drum gets older, light does no t di sch ar g e i t as much (se e th e upper right chart). This may cause dirty background on copies. VR pattern detection ev ery 1,000 copies using the ID sensor avoids this problem.

Every time VR pattern detection is done, a strip across the drum is charged using zero development bias and the standard charge on the drum charge roller that is used for copying (with all corrections included). At the same time, all the blocks of the erase lamp turn on to illuminate this charged area of the drum.

Copy volume

Drum residual voltage

(V)

Light intensity

Drum potential

(V)

Old Drum New Drum

VR Pattern

0V Bias

ID Sensor

A156/A160/A162 2-18 STM

If there is residual voltage on the drum, this area of the drum will attract some toner, making a VR pattern. The ID sensor checks the ref l ect ivity of the VR pattern. This sensor output voltage is VRP.

In VR detection, VRP is compared with VRG.

• V

is the reflectivity of the bare area of the drum, measured by the ID

sensor. It has the same value as VSG (see Image Density Control - V

and VSP Detection).

• V

is the output from the ID sen sor reflected from the VR pattern.

When the drum residual voltage increases, the VR pattern becomes darker. Then, VRP decreases and th e VRP/VRG ratio decreases.

Then the CPU increases the negative development bias voltage to prevent dirty background, and simultaneously increases the negative drum charge roller bias voltage to prevent low image density. This is the VR correction.

Table 11. VR correction

ID Correction Drum Charge Roller

Correction Voltage

Development Bias

Correction Voltage

±0 V

–40 V –80 V

RP/VRG

x 100(%)

64 ~ 100 60 ~ 100 54 ~ 100

0 V

0 V 47 ~ 63 42 ~ 59 36 ~ 53 –40 V –40 V 35 ~ 46 30 ~ 41 24 ~ 35 –80 V –80 V 26 ~ 34 21 ~ 29 16 ~ 23 –120 V –120 V

0 ~ 25 0 ~ 20 0 ~ 15 –160 V –160 V

For example, taking the ID corr e ctio n to be zero for no w, i f VRP/V

is 45%,

the drum charge and development bias corrections will both be -80V. VR correction also depends on the current VSP pattern ID correction that is

being used. If development bias has been increased by ID correction, the V

correction may be smaller in some cases to take this into account. This is shown by both the table above and the following figure.

ID correction

0 V

–40 V –80 V

Detailed

Descriptions

STM 2-19 A156/A160/A162

Using the same example to illustrate this, but with an ID correction of -40V, the corrections will both be -40 V this time.

Note that forced VR detection by SP mode must be done when a new drum is installed or the ID sen sor cl ea ne d or rep l ace d. (S ee Ser vi ce Tabl e s Practical SP Mode Use Tables for the correct sequence of SP modes to perform at this time). The correction is done in the same way as described above.

A156/A160/A162 2-20 STM

1.4.2 VL Pattern Correction

Dirty optics or deterioration of the exposure lamp decreases the intensity of the light that reaches the dr um vi a th e op tics cavi t y. As m ore copie s are made during the drum’s life, the ph otoconductive layer gets worn and the response of the drum to the exp osu r e lamp weake ns.

VL pattern correction counteracts dirty backgrou nd cause d by the fa cto rs mentioned above.

The VL pattern is a light gra y senso r pat te r n on the ope r at or side of the bottom of the left scale bracket. The ID sensor output at VSG detection in memory is used again as VLG (the reflectivity of the bare area of the drum).

When VL pattern detection starts, the exposure lamp turns on and the main motor stays on to rotate the drum. The drum charge roller, all the blocks of the erase lamp, the pre-transfer lamp, and the quenching lamp turn on. Then, the appropriate blocks of the erase lamp tu rn of f an d on to make a V

pattern on the drum surface. In VL detection, VLP is compared with VLG.

•

VLG is the reflectivity of the bare area of the drum, measured by the ID sensor. It has the same value as VSG (see Image Density Control - V

and VSP Detection).

•

VLP is the output from the ID sen sor reflected from the VL pattern.

ID Sensor

VL Pattern

Exposure lamp voltage

(V)

Drum Potential

Initial Conditions

Deteriorated Conditions

Detailed

Descriptions

STM 2-21 A156/A160/A162

VL detection is done at the following times:

• Every 1000 Copies

• Forced Detection: whe ne ver a ne w drum or exp osu r e lam p is installed,

or exposure lamp voltage is adj ust ed , or whe n th e op ti cs are cleaned, forced VL detection (SP3-105) must be executed. (See Service Tables Practical SP Mode Use Tables for the correct sequence of SP modes to perform at this time).

Forced VL detection is differ e nt fr om th e r ou tin e 1,000 copy VL detection, so it is explained below in detail. During forced VL detection, BL and V

REF

are determined as show n be l ow.

NOTE: BL = Development bias used for VL correction.

BL starts at -50 V and -20 V is added until the value of VLP is appropriate.

VL Correction Method

During VL pattern detection, lamp voltage, drum charge voltage and development bias are as follows.

•

Lamp voltage: same as during normal copying (ADS mode)

•

Drum charge voltage for the VL pattern: same as during normal copying

• Development bias for forced V

detection: BL + VR correction + V

BL(ID)

•

Development bias for VL detection every 1000 copies:

= BL + (–25 V) + VR correction + V

BL(ID)

VBL (ID) is an ID compensation factor based on the current ID correct ion used for the VSP pattern (see Image Density Control for details on this ID Correction). It is ap pl ied as shown in Table 12.

Table 12

ID correction 0 V –40 V –80 V V

(ID)

0 V

–10 V –20 V

BL= BL -20V

VLP/VLG > 0.45?

VLP, VLG detection

START: BL = -50V

BL = current BL V

REF

= VLP/V

YES

SP3-105

Fig. 19

A156/A160/A162 2-22 STM

- Forced V

Detection -

When forced VL detection (SP3-1 05 ) is exe cut ed , the CPU stores the V

reference value (V

REF

) in memory (see Fig. 19).

REF

= initial VLP/V

- Every 1,000 copies -

After the forced VL detection, VL detection is performed at the end of every 1000 copies. The VLP/VLG value at that time is called V

DAT

= current VLP/V

- During Copying -

The CPU compares the latest V

DAT

with the latest V

REF

and applies a V

correction to the exposure lamp voltage as shown below.

Table 13. VL Correction

ID Correction Lamp

Correction

Voltage

±0 V

–40 V –80 V

DAT/VREF

x 100 (%)

146 ~ 156 ~ 168 ~ –1 V 101 ~ 145 101 ~ 155 101 ~ 167

0 V

~ 100 ~ 100 ~ 100 +1 V

In general, the lamp will be dimmed slightly if the VLP pattern reflectivity has increased significantly (the VLP pattern is paler ) , an d m ade brighter if the reflectivity has decreased (the VLP pattern is dark er) .

VL correction also depends on the current VSP pattern ID correction that is being used (see Image Density Control - ID Correction for the VSP pattern).

For example, taking the ID corr e ctio n to be zero for no w, i f V

DAT/VREF

is 150%, the lamp correction will be -1V (made slightly dimmer). Using the same example, but with an ID correction of -40V, the correction will be 0 V this time.

ID correction

0 V –40 V –80 V

Detailed

Descriptions

STM 2-23 A156/A160/A162

1.4.3 T/H Correction

The drum charge efficiency is the ratio of the charge actually on the drum to the charge that was applied to the drum. It varies with the temperature around the drum charge roller. It drops off at lower temperatures, so the lower the temper at ur e is, the hi gh er th e cha r ge tha t i s re qu ir ed .

Also, as the drum ages, the photoconductive layer gets worn. This causes a decrease in the drum potential after charging.

The drum charge thermistor detects the temperature (T) around the drum charge roller. The dr um cha r ge ro l ler voltage is changed to account for the effects of temperature on drum charge efficiency.

The CPU also keeps track of the drum rotation time (H) that corresponds to the wear on the drum sur f ace. The drum charge roller volt ag e i s incr ea sed at set intervals.

These corrections for the drum charge roller voltage are called T/H correction.

The T/H correction that is applied during copying dif fers from that applied when making ID sensor patterns. See below for how the correction is determined.

The T/H correction difference between the A153, A155, and A156 copiers and the A157, A159, and A160 copiers is a result of the difference in copy processing speed (200 mm/s for the A153, A155, and A156 copiers, compared with 150 mm/s for the A157, A159, and A160 copiers).

Potential of new drum

Change in drum potential with use

A156/A160/A162 2-24 STM

Table 14. T/H Correction (Copying) - Base drum charge voltage = -1500 V

A153, A155, and A156 copiers

Drum Charge Roller

Temperature (T )

Drum Rotation Time (H)

0 ≤ H < 40 40 ≤ H < 110 110 ≤ H

37.1 ≤ T

-60.0 -60.0 -60.0

29.6 ≤ T < 37.1

-203.4 + 3.9xT -203.4 + 3.9xT -203.4 + 3.9xT

17.9 ≤ T < 29.6

-729.1 + 21.6xT -923.9 + 28.2xT -1116.1 + 34.7xT

12.6 ≤ T < 17.9

-1345.1 + 56.0xT -1705.8 + 71.9xT -2068.9 + 87.9xT

T < 12.6

-639.0 -800.0 -961.0

A157, A159, and A160 copiers

Drum Charge Roller

Temperature (T)

Drum Rotation Time (H)

0 ≤ H < 40 40 ≤ H < 110 110 ≤ H

32.4 ≤ T

-80.0 -80.0 -80.0

28.2 ≤ T < 32.4

-426.7 + 10.7xT -426.7 + 10.7xT -426.7 + 10.7xT

18.0 ≤ T < 28.2

-621.8 + 17.6xT -768.4 + 22.8xT -912.2 + 27.9xT

12.4 ≤ T < 18.0

-1028.6 + 40.2xT -1357.2 + 55.5xT -1689.7 + 71.1xT

T < 12.4

-530.0 -669.0 -808.0

Table 15. T/H Correction (VSP Pattern) - Base drum charge = -1300 V A153, A155, and A156 copiers

Drum Charge Roller

Temperature (T)

Drum Rotation Time (H)

0 ≤ H < 40 40 ≤ H < 110 110 ≤ H

37.1 ≤ T

+40.0 +40.0 +40.0

29.6 ≤ T < 37.1

-103.4 + 3.9xT -103.4 + 3.9xT -103.4 + 3.9xT

17.9 ≤ T < 29.6

-489.9 + 16.9xT -603.8 + 20.8xT -717.6 + 24.6xT

12.6 ≤ T < 17.9

-862.5 + 37.7xT -1164.2 + 52.1xT -1465.9 + 66.4xT

T < 12.6

-387.0 -508.0 -629.0

A157, A159, and A160 copiers

Drum Charge Roller

Temperature (T)

Drum Rotation Time (H)

0 ≤ H < 40 40 ≤ H < 110 110 ≤ H

32.4 ≤ T

+24.0 +24.0 +24.0

28.2 ≤ T < 32.4

-283.9 + 9.5xT -283.9 + 9.5xT -283.9 + 9.5xT

18.0 ≤ T < 28.2

-402.6 + 13.7xT -532.4 + 18.3xT -662.2 + 22.9xT

12.4 ≤ T < 18.0

-719.3 + 31.3xT -919.5 + 39.8xT -1117.6 + 48.2xT

T < 12.4

-331.0 -426.0 -520.0

For example, when copying with an A157 copier at 25°C with a drum that has a rotation time of 100 hours:

•

The T/H correction is -768.4 + (22.8 x 25) V = -198.4 V.

•

The drum charge roller vol ta ge is th e ba se voltage plus the T/H correction

= (-1500) - 198.4 = -1698.4 V.

Detailed

Descriptions

STM 2-25 A156/A160/A162

1.5 PROCESS CONTROL DURING ABNORMAL CONDITIONS

When an abnormal sensor condition occurs, some process controls are disabled.

Abnormal Condition

Process Control

ID Sensor Adjustment

Correction VL Correction

ADS Sensor Adjustment

Thermistor Error

Disabled

TD Sensor Adjustment Error

TD Sensor Detection Error

Error

ID Sensor Adjustment Error

Executed

ID sensor adjustment error → Disabled If the ID sensor can be adjusted → Executed

Error

A156/A160/A162 2-26 STM

1.6 SUMMARY

1.6.1 Process Control and Sensor Detection Timing

A summary of process control and correction timing is shown below.

Correction

Electrical

Component

Sensor

Output Used

Correction Timing

Corrected

Value

Forced Correction

Automatic Correction

Manual ID correction

Operation panel

——

Every copy in manual ID mode

•

Lamp voltage

•

Dev. bias

Reproduction

ratio

correction

Operation panel

——

Every copy in reduce/enlarge mode

Development bias

ADS

correction

ADS sensor

ADS

(pattern)

ADS

(original)

—

•

ADS Mode: Once per original (ARDF mode), or once when the Start key is pressed (Platen mode)

Development bias

New drum, ADS sensor, or exposure lamp

Every 1000 copies

•

ADS

(pattern)

stored

correction

and

Toner

density

control

ID sensor V

New drum or ID sensor replacement

At the start of each copy job

•

Dev. bias

About every 10 copies

•

Toner supply clutch ON time

TD sensor V

When the developer is changed

Every copy

correction

ID sensor V

, V

New drum or ID sensor replacement

After every 1000 copies

•

Drum charge roller voltage

•

Dev. bias

correction

ID sensor V

, V

New drum or exp. lamp

Lamp voltage

T/H

correction

•

Drum charge roller thermistor

T: (temperature) H: (drum rotation time)

H is reset at the drum initial setting

Every copy

Drum charge roller voltage

•

RAM Board

Detailed

Descriptions

STM 2-27 A156/A160/A162

1.6.2 Process Control Checks During Machine Operation

This section shows what the machine checks and recalibrates to control the copy process at different ti mes.

Every Copy

The machine automatically adjusts the following process control parameters every copy.

IMAGE DENSITY

CONTROL

VSG Correction

Uses: ID Sensor Affects: Development bias Toner suppl

clutch on time

IMAGE DENSITY

CONTROL

Correction

Uses: TD sensor Affects: Development bias Toner suppl

clutch on time

DRUM POTENTIAL

CONTROL

T/H Correction

Uses: Drum char

e thermistor Drum rotation time to date Affects: Drum char

e roller voltage

COPY IMAGE CONTROL

Reproduction Ratio

Correction

Reduce

or Enlarge

Mode?

Uses: Selected reproduction ratio Affects: Development bias Done: Ever

cop

YES

COPY IMAGE CONTROL

Manual ID Correction

COPY IMAGE CONTROL

ADS Correction

Which ID Mode?

MANUAL

Uses: Selected ima

e density settin

Affects: Development bias Exposure lamp volta

Done: Ever

cop

Uses: ADS sensor Affects: Development bias Done: Sin

le copy of an original -

Ever

cop

More than one copy of the same ori

inal -

Ever

copy (but only for the

first cop

run

)

ADS

IMAGE DENSITY

CONTROL

VSP Detection

Done at the end of the cop

run if more than 10 copies have been made since the

previous V

detection.

Uses: ID Sensor Affects: Development bias Toner suppl

clutch on time

Done at the start of ever

copy run

Done ever

cop

Done every cop

A156/A160/A162 2-28 STM

Every 1000 Copies

After every 1,000 copies, the machine calibrates the following reference values for the various processes that are used in process control.

NOTE:

If the auto process co ntrol mode has been disabled with SP3-801, this process control cycle will not be performed.

After Adding New Developer

The technician must do the following SP mode after adding new developer.

IMAGE DENSITY CONTROL

Reset

COPY IMAGE CONTROL

Auto ADS Gain Ad

ustment

DRUM POTENTIAL

CONTROL

Correction

Resets VSG to 4 ± 0.2 V.

DRUM POTENTIAL

CONTROL

Correction

Measures V

Sets VRG = V

Uses: ID sensor Affects: Development bias Drum char

e roller voltage

Uses: ID sensor Affects: Exposure lamp volta

Uses: ADS sensor output Affects: Development bias

Uses: ID sensor Affects: Development bias Toner suppl

clutch on time

Measures V

Sets VLG = V

Adjusts ADS sensor ouput volta

e for the ADS sensor pattern to 2.7 ± 0.1 V.

IMAGE DENSITY CONTROL

TD Sensor Initial Settin

SP 2-214 Resets the TD sensor output to 2.5 ± 0.1 V Resets ID correction for the V

pattern to

zero

(

this affects development bias and

exposure lamp volta

ge)

Detailed

Descriptions

STM 2-29 A156/A160/A162

After Installing a New Drum

The technician must do a series of SP modes to reset the process control parameters related to the drum.

IMAGE DENSITY CONTROL

Reset

DRUM POTENTIAL

CONTROL V

Detection

DRUM POTENTIAL

CONTROL

Detection

ADJUSTMENT

Exposure Lamp Volta

DRUM INITIALIZATION

SP 3-123 Resets the followin

VR correction level V

correction level T/H correction level Drum rotation time

SP 3-001 Ad

usts VSG to 4 ± 0.2 V

SP3-112 Detects the initital V

value for the new drum

SP4-001 See "Removal and Ad

ustment -

Cop

Quality Adjustments"

COPY IMAGE CONTROL

Auto ADS Gain Ad

ustment

SP 4-201 Ad

usts the ADS sensor

output to 2.7 ± 0.1 V

SP 3-105 Detects the initial V

LP/VLG

value for the new drum

A156/A160/A162 2-30 STM

Development bias, drum charge voltage, and exposure lamp voltage

The following table shows how process control affects development bias, drum charge, and exposure lamp voltages for various machine operations.

Mode Development Bias [V] Drum Charge Voltage [V] Exposure Lamp Voltage [V]

Copying

ADS mode

(–240) + ADS correction +

Reproduction

ratio

correction

+ B

(–1500) +

correction

⁄

correction

+ C

Vexp +

correction

Manual

mode

ID Level 1 ~ 6

(–240) +

Manual ID

correction

Reproduction

ratio

correction

+ B

Vexp +

Manual ID

correction

ID Level

(–240) +

Lightest ID level

dev.

bias

Reproduction

ratio

correction

+ B

VSP Pattern Detection (–300) + BP + ID correction

(–1300) +

⁄

correction

+ CP

VR Pattern Detection 0

(–1500) +

correction

⁄

correction

+ C

Pattern

Detection

Forced V

Detection

BL +

correction

+ VBL (ID)

Vexp

VL Detection

BL + (–25) +

correction

+ VBL (ID)

Vexp +

correction

Non Image Area

(–200) +

correction

+ VBL (ID)

Auto ADS Gain

Adjustment

Vexp +

correction

NOTE:

B = Development bias adjustment factor, selected with SP2-201-001. BP = Correction to the development bias used for making for V

patterns, selected with SP2-203.

BL = The value of the development bias that was reached during the most recently performed forced V

detection routine.

(ID) = ID compensation factor based on the current ID correction used for making VSP patterns. C = Correction to the drum charge voltage, selected with SP2-001. CP = Correction to the drum charge voltage for maknig V

patterns, selected with SP2-003.

Vexp = Exposure lamp voltage, selected with SP4-001.

STM 2-31 A156/A160/A162

2. DRUM

2.1 DRUM UNIT

The drum unit consists of the components shown in the above illustration. An organic photoconductor (OPC) drum (diameter: 60 mm) is used for this model.

1. OPC Drum

2. Drum Charge Roller

3. Drum Charge Roller Cleaner

4. Drum Charge Thermistor

5. Cleaning Blade

6. Pick-off Pawl

7. ID Sensor

8. Recycled Toner Transport Coil

A156/A160/A162 2-32 STM

2.2 DRIVE MECHANISM

The drive from the main motor is transmitted to the drum drive pulley via the timing belt [A]. The pi ck-of f pa w ls [B] are al wa ys in cont act with the drum surface under a light spr ing pr essu re. They m ove fr om side to side duri n g the copy cycle. This movement is made with a worm gear [C] and an eccentric cam gear [D].

[A]

[D]

[C]

[B]

Detailed

Descriptions

STM 2-33 A156/A160/A162

3. DRUM CHARGE

3.1 OVERVIEW

This copier uses a drum charge roller system instead of a corona wire scorotron system to charge the drum. For the cop y image area or during process control, the dru m charge roller [A] contacts the surfac e of the OPC drum [B] to give a sufficient negative charge.

The drum charge roller system has the following advantages over the corona wire scorotron system:

• The amount of ozone ge ne r at ed dur in g dr u m charging is less than 1/10

of that for a corona wire scorotron system.

•

The applied voltage is 1/2 ~1/3 that of a wire scorotron system.

•

The efficiency of drum char gin g i s high .

Thanks to the above advantages, no ozone filter is required for this copier. The CB high voltage sup ply bo ard [C] gives a constant dc voltage of –15 00

V (–1300 V for the VSP pattern) to the drum charge roller at the charge roller terminal [D]. This gives the drum surface a negative charge of –900 V (–600 V for the VSP pattern).

[C]

[D]

[B]

[A]

A156/A160/A162 2-34 STM

3.2 DRUM CHARGE ROLLER DRIVE MECHANISM

To prevent toner from adhering to the drum charge roller and to prevent the drum charge roller from sticking to the OPC drum, the drum charge roller contacts the OPC drum only under the following conditions: (1) When the imag e processing area comes under the drum charge roller (2) When process control is executed.

This function is performe d by th e tr a nsf er be lt con ta ct cl ut ch [A ] ( a on e-third turn clutch) and cam [B] located on the rear side plate of the copier. When the clutch [A] is dri ven one third of a complete rot ation, the cam [B] drives lever [C] upward. The lever is linked with the plate [D] which releases the on-off lever [E] of the drum charge roller. Then the drum charge roller contacts the drum as a result of the pressure from the two springs [F]. At the same time, plate [D] also pushes the lever [G] on the drum charge thermistor [H]. Then, the drum charge thermistor moves away from the drum charge roller. When the start key is pressed, the temperature around the drum charge roller is measured while the drum charge thermistor contacts the drum charge roller. After that, the temperature is measured while the drum charge thermistor is away from the drum charge roller.

Rev. 7/95

[B]

[C]

[B]

Home Position

During Image Processing

The drum charge roller is away from drum

The drum charge roller contacts the drum

[B]

[D]

[E]

[F]

[C]

[F]

[A]

[H]

[G]

Detailed

Descriptions

STM 2-35 A156/A160/A162

When the drum charge roller does not contact the drum, the drum charge roller is driven by the main motor through gears [A]. (The roller speed is 50 rpm for A153, A155, and A156 copiers, and 37 rpm for A157, A159, and A160 copiers.) At this ti m e, the rol ler to uch es th e clea ni n g pa d, and this helps keep the roller clean, although a cleaning routine automatically takes place at the end of every copy cycle (see below).

When the drum charge roller contacts the drum, the force (torque) imparted by the drum becomes gre ater than the force transmitted through the clutch [B]. Then, the drum charge roller rotates with the drum.

The drum charge roller com es awa y fr om th e dru m aft er eve r y copy job . For 2 seconds after the end of every copy job and for 10 s econds after every copy interval set by SP2-901 , th e dr u m char g e roll e r is dri ve n by th e m ain motor via gears [A] for cleaning (see "Drum Charge Roller Cleaning").

After cleaning, the main motor stops. While the main motor is not rotating, the drum charge roller is kept away from the drum. This prevents the drum charge roller fr om ad hering to the drum.

[B]

[A]

A156/A160/A162 2-36 STM

3.3 DRUM CHARGE ROLLER CLEANING

If the drum charge roller gets dirty, drum charge efficiency decreases. This affects the copy quality, for example causing vertical white lines.

While the drum charge roller is away from the drum but still rotating, it brushes against the cleaning pad [A], which helps to keep it clean.

However, there is a specific drum charge roller cleaning routine which is described below. It is executed at the following intervals:

(1) For 2 seconds at the end of every job (2) For 10 seconds after the copy job interval set by SP2-901.

After the copy job, the drum ch arge roller comes away from the drum and contacts the drum charge roller cleaning pad [A]. The main motor still rotates during cleaning and drives the gear [B] to swing the lever [C] via an eccentric cam. This lever swings the arm [D] and the arm gives a side-to-side movement to the drum charge roller cleaner.

The cleaning interval set by SP 2- 9 01 is as fol lows : SP2-901 setting: 0: Every 1000 copies (10 seconds) [default]

1: Every 500 copies (10 seconds) 2: Every 200 copies (10 seconds) 3: Every 100 copies (10 seconds)

For a user who mainly makes consecutive high volume copy runs, the drum charge roller is li kel y to get dir ty ea r l y, be cau se the interval between jobs (and thus the interval between end-of-copy-job cleaning runs) is longer than for small volume intermittent copy runs. In this case, the copy count interval for cleaning must be r ed uce d w ith SP2-901, to have the ten-second cl ea ni n g routine done more often.

[C]

[D]

[A]

[B]

Detailed

Descriptions

STM 2-37 A156/A160/A162

3.4 TEMPERATURE COMPENSATION

The applied voltage varies with the temperature around the drum charge roller. The lower the temperature is, the higher the applied voltage required. This affects the drum charge efficiency.

To compensate for these characteristics, the drum charge thermistor [A] detects the temperature around the drum charge roller. Before the copy job starts, the drum charg e th erm i st or con ta c ts th e dru m charg e r olle r , T/H correction for the first copy uses the temperature detected while the drum charge thermistor con ta cts th e dr u m charg e rol le r . Af te r the copy j ob star t s, the thermistor is away from the drum charge roller. After the 2nd copy, T/H correction uses the temperature detected while the drum charge thermistor is away from the drum charge roller. Using the detected temperature, T/H correction is performed. (See "T/H correction" in the Process Con trol section for details.)

To avoid low drum charge efficiency for the first copy after the main switch is turned on, there i s a dr um he ater [B] located over the drum an d dr u m char g e roller. This heater is turned on while the copier main switch is turned off. It keeps the temperature around the drum and drum charge roller over 15°C. For this heater to operate, the power cord of the copier must be plugged in even when the main switch is turned off.

Rev. 7/95

[B]

[A]

A156/A160/A162 2-38 STM

4. OPTICS

4.1 OVERVIEW

The optics unit reflects an image of the original on the expo sur e gl ass on to the OPC drum. This fo r ms a late nt electrical image of the or igi n al .

In this model, a halogen lamp is used for the exposure lamp [A]. The lamp surface is frosted to ensure even exposure. The specifications of the lamp are as follows. Note that the A153/155/156 models are faster, so they need more light during exposure.

115V Machines 230V Machines

A153/A155/A156

97V 280W 85V 280W

A157/A159/A160

97V 200W 85V 200W

Six mirrors are used to make the optic s unit smaller and obtain a wide reproduction ratio range (50 ~ 200%).

The lens [B] is driven by two stepper motors for (1) vertical movement (parallel to the paper feed direc tion) and (2) horizontal movement. Also, to correct for focal length change in reduction and enlargement modes, the third scanner unit [C] (4th and 5th mirrors) is moved (3) vertically (parallel to the paper feed direction) by another stepper motor.

A toner shield glass [D ] an d a gr e en fi lte r [E] are installed above the OPC drum to improve reproduction of red images or text.

Rev. 7/95

[A]

[B]

[E]

[D]

[C]

(2)

(1)

(2)

(1)

(3) (3)

[B]

[C]

Detailed

Descriptions

STM 2-39 A156/A160/A162

The CPU monitors the temp era tu r e ar o und th e op ti cs cavit y thro ug h a thermistor which is under the left scale. When the detected temperature reaches a certain threshold value (see the following table), the optics cooling fan(s) on the rear of the optics side plate starts to draw cool air into the optics cavity. The hot air exit s thro ug h th e ven ts i n the up pe r cover. The fan(s) operate until the temperature drops below the threshold temperature. Note that the A153/155/156 models have two fans; this is because the exposure lamp is more powerful in this model, so more cooling is needed.

A153/A155/A156 A157/A159/A160

Rotating temperature

45°C40

Number of fans

The thermofuse (located on th e 1st scanner) provides back-up overheat protection. It opens at 121°C and removes ac power to the exposure lamp. The thermofuse is not resettable.

An optics anti-condensation heater is available as opti onal equipment (it is also a service part). To prevent moisture from forming on the optics, it turns on while the main switch is turned off.

The main board controls the exposure lamp voltage through the ac drive board. The exposure lamp voltage is based on the base lamp voltage (set by SP4-001) and various correction facto rs. The correct ion s depen d on whet he r the image density is manually selected or whether ADS mode is selected. For details, see Process Control - Summary.

A156/A160/A162 2-40 STM

4.2 SCANNER DRIVE

In this model, a stepper mot or [A ] dr ive s the scann er s via a ti mi n g be lt [B ], scanner drive pulley [C], and two long & short scanner drive belts [D,E]. To prevent skewing, both ends of each scanner are driven. The scanners have sliders [F], which ride on guide rails.

Unlike previous models, the scanner drive pulleys are made of aluminum. Also, bearings at the ends of the scanner drive pulley shaft assure reliable scanner speed and movement. The timing belt tension has increased as well.

The scanner home position is detected by the home position sensor [G]. The main CPU sends the appropriate pulses to the scanner drive motor (determined from th e de tected original size) to deter mi ne the scann er r et ur n position.

The first scanner [H], which consists of the exposure lamp and the first mirror, is connected to the tw o long scann er dr i ve belt s wit h be l t clam p s. The second scanner [I], which consists of the second and third mirrors, is connected to the two short scann er dr iv e belt s wit h be lt cl am p s.

The first scanner drive speed in full size mode is:

200 (mm/s) for A153/A155/A156 copiers 150 (mm/s) for A157/A159/A160 copiers

The first scanner drive speed for a selected reproduction ratio is:

200/M (mm/s) for A153/A155/A156 copiers 150/M (mm/s) for A157/A159/A160 copiers

NOTE:

M = Selected reproduction ratio (0.5 - 2.0)

The second scanner moves at half the velocity, and the returnin g spe ed of the first scanner is 1150 (mm/s) for all models.

[F]

[E]

[H]

[C]

[A]

[G]

[I]

[B]

[D]

Detailed

Descriptions

STM 2-41 A156/A160/A162

4.3 LENS DRIVE

– Vertical (Parallel to the Paper Feed Direction) –

The lens vertical drive motor [A] changes the vertical position [B] of the lens in accordance with the select ed repr o du ctio n r at io ( 50 ~ 200%) . The mot or , which is a stepper motor, drives the lens through the lens drive wire [C].

The lens vertical home position sensor [D] detects the vertical position of the lens for full size mode. The vert i cal po siti o n of the le ns fo r the select ed reproduction ratio is determined by the number of pulses fro m the full size position.

– Horizontal (Perpendicular to the Paper Feed Direction) –

The original’s horizontal posi tion on the exposure glass varies depending on the mode (platen or ADF). This prevents problems such as skewing that are caused when the original moves to o cl ose to the r ea r scal e in au to mat i c feed mode. However, the cent er is the stan da r d po siti o n for copy pa pe r fee d.

Therefore, the hori zo nt al po si tio n [E ] of the lens has to be changed in accordance with paper size, reproduction ratio, and original feed mode.

The lens horizontal drive motor [F] drives the lens through the lens drive wire [G]. The lens horizontal home position sensor [H] detects the horizontal position of the lens. The home position of the lens is the horizontal position for A4/LT sideways in full size and platen mode; the positions for other conditions are determined by counting the number of motor drive pulses from the home posi tio n.

Since this model has a horizontal lens drive mechanism, side-to -si de registration adjustment for each feed station can be done easily using SP mode (SP4-011).

[G]

[D]

[H]

[F]

[C]

[A]

[E]

[B]

A156/A160/A162 2-42 STM

4.4 HORIZONTAL LENS POSITIONING

4.4.1 Original Alignment Position

There are two standard original alignment positions: one for platen mode and one for ADF mode.

In platen mode, the original is aligned with both the rear [A] and the left [B] original scales (the rear l ef t corn er [C] is the standard alignment position) .

In ADF mode, the original alignment position is 3.5 mm to the front of the platen mode original alignment position. This is to maintain the original transport path (w h ich i s at 3.5 mm from the rear scale).

On line [D] in the above diag r am, you can see th e ho r i zon ta l positions of the lens for each original mode, with identical sizes of paper.

4.4.2 Paper Size

To maintain a high paper feed performance, the center line of the exposure glass is assigned to be the standa r d pape r fee d po siti o n. Howeve r , as described above, the original alignment position for original feed is not in the center of the exposure glass in this model. Therefore, the lens horizontal position has to be changed in accordance with the paper size.

The diagram shows the horizontal position of the lens for three paper sizes (A, B, and C) in full size mode.

Platen ADF

Center

Lens Position

Horizontal

[C]

[D]

[A]

[C]

[B]

Horizontal

Lens Position

Copy Paper

Detailed

Descriptions

STM 2-43 A156/A160/A162

4.4.3 Reproduction Ratio

The horizontal position of the lens has to be changed when a reproduction ratio is selected. This is because the original is aligned at the rear left corner but the copy paper is fed do w n th e cen te r .

When the reproduction ratio is changed, the vertical position of the lens is changed. At the same ti me, the total focal length has to be chan ge d to adju st the image focusing. For this focal length change, the vertical position of the 3rd scanner is also adjusted.

The figure shows the vert i cal an d ho r i zon ta l posit i on of th e l en s for r at i os of 50, 100 and 200%.

Copy Paper

Original

200% 100%

50%

100%

50%

3rd Scanner Position

200%

Original Rear Edge

Horizontal Position

Vertical Position

A156/A160/A162 2-44 STM

4.5 3RD SCANNER DRIVE

To compensate the fo cusing for reproduction and lens position changes, the 3rd scanner (4th and 5th mirrors) position is changed.

The 3rd scanner drive motor [A] (a stepper motor) changes the 3rd scanner position through the pinion gears [B] and the rack gear [C].

The 3rd scanner home position sensor [D] detects the 3rd scanner position for full size mode. The machine keeps track of the 3rd scanner position based on the number of motor drive pulses.

[D]

[C]

[B]

[A]

Detailed

Descriptions

STM 2-45 A156/A160/A162

4.6 UNEVEN LIGHT INTENSITY CORRECTION

The entire exposure lamp surface is frosted to ensure even exposure. To compensate for reduced light at the edge of the lens, a shading plate is

placed in front of the lens. The shading plate is fixed to the lens unit. The shading plate corrects the light intensity when the lens horizontal position is shifted (from [A] to [C]).

Also, two shading mylars [D] in te rc ep t an y stray r ef lect ed lig ht fr om ou tsi d e the light path.

[D]

[A] [B] [C]

Original

Shading Plate

Exposure Intensity

Illumination Distribution

[A] [B]

[C]

A156/A160/A162 2-46 STM

4.7 ORIGINAL SIZE DETECTION IN PLATEN MODE

There are three reflective sensors in the optics cavity for original size detection. The Original Width Sensor [A] detects the original width and the Original Length Sensor-1 [B] and Original Length Sensor-2 [C] detects the original length. These are the APS (Auto Paper Select) sensors.

For North American models, there is an optional length sensor for detecting 11" x 15" originals.

Inside each APS sensor , the r e is an LE D [ D] an d ei t he r thr e e ph ot oelectric devices [E] (for the widt h sen sor ) or on e ph otoelectric device (for each length sensor). In the width sensor, the light generated by the LED is broken up into three beams and each be am scan s a diff er e nt point of the exposure glass (in each length sensor, there is only one beam). If the original or platen cover is present over the scan nin g po i nt , th e beam is reflected and each ref lected beam exposes a photoelectric device and activates it.

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 cov er is opened.

[E]

[D]

[C]

[B]

[A]

Detailed

Descriptions

STM 2-47 A156/A160/A162

Original Size Length Sensor Width Sensor

A4/A3 version LT/DLT version

12Op345 A3 11" x 17" OOOOOO — (11" x 15") O O X O O O B4 10" x 14" OOOOOX F4 8

1/2

" x 14" O O O O X X

F 8" X 13" O O O O X X

A4–L 8

1/2

" x 11" X O O O X X B5–L — X O O X X X A5–L 5

1/2

" x 8

1/2

" XXOXXX

A4–S 11" x 8

1/2

" XXOOOO B5–S — X X O O O X A5–S 8

1/2

" x 5

1/2

"XXOOXX

The original size data is taken by the main CPU when the platen position sensor [A] is activated. Thi s is when the plat en is po siti o ned ab ou t 15 cm above the exposure glass. At this ti m e , on ly the senso r( s) locat ed underneath the original receive the reflected light and switch on. The other sensor(s) are off. The main CPU can recognize the original size from the on/off signals from the five sensors.

If the copy is made with the platen open, the main CPU decides the original size only from the sensor ou tputs when the Print key is pressed.

The above table shows the outputs of the sensors for each original size. The third length sensor (shown as "Op") is the optional length sensor for detecting 11" x 15" origin als in North American models. (See FSM page 3-23)

This original size detectio n m et ho d eli mi n at es th e ne cessity for a pre-scan and increases the machine’s productivity.

Original size dete cti o n usin g the ARDF is described in the manual fo r the ARDF.

[A]

Note:

–L= Lengthwise, –S = Sideways, O = High (Paper Present), X = Low

A156/A160/A162 2-48 STM

4.8 AUTOMATIC IMAGE DENSITY CONTROL SYSTEM (ADS)

Just before taking a copy in ADS (Auto Image Densit y Select) mod e, the ADS sensor [A] meas ure s the or igi n al background density and the main CPU changes the development bias for the original to prevent dirty background from appear ing on the copy. The exposure lamp voltage is fixed at the manual ID level 4 value (set by SP4-001) regardless of the input from the ADS sensor.

The ADS sensor board is mounted on the rear side of the optics side plate. The sensor board is covered by the sensor housing cover which has a small hole to allow light reflected from th e original to reach the ADS sensor.

ADS Sensor Gain Adjustment (Eve ry 1, 00 0 C opie s)

To maintain consistent image quality regardless of changes in the components of the optic path with time, the ADS sensor reference voltage is adjusted to 2.7 ± 0.1 V every 1K copies. The exposure l amp turn s on at ID level 4, and the light reflected by the white ADS pattern [B] reaches the ADS sensor. The CPU adjusts the ADS gain value to make the output (V

ADS

pattern) equal to 2.7 ± 0.1 V. The gain value is stored in the RAM board. If the output cannot be made to equal 2.7 ± 0.1 Volts even if the ga in is

adjusted as far as it will go, the machine generates a Service Call code.

[B]

[A]

Detailed

Descriptions

STM 2-49 A156/A160/A162

During Copying

To maintain good copy qualit y, the development bias changes depending on the background density detected by the ADS sensor.

In full size mode when the user selects ADS, the CPU samples the ADS sensor output across the original from 5 mm to 15 mm from the left scale edge. The CPU takes the maximum ADS sensor output during the sampling period and compares it with the ADS reference voltage (V

ADS

[pattern]; see the previous page). Base d on this comparison, the machine may ad just the development bias to eliminate dirty background (see the Process Control ADS Correction section for details).

The sampling length of the ADS sensor output for the original differs depending on the reproduction ratio because the scanner speed is different.

Sampling is performed on each copy. (If more than one copy is made of the same original, sampling is only do ne for the first copy run.)

Note:

There is an optional extra ADS sensor for users who have copy quality problems w it h certain types of red original. (Se e FSM pa ge 3-24)

Maximum

ADS Sensor Output

[V]

A = 5 B = 20/M - 5 (mm)

M: Reproduction rati o (0.5 ~ 2.0)

ADS Voltage from the Original

60 mm

38 mm

A156/A160/A162 2-50 STM

5. ERASE

5.1 OVERVIEW

LE: Leading edge erase margin: 3.5 ± 2.5 mm SE: Side erase margin: total of both sides is 3 mm or less Lo: Original width Lc: Charged width of the drum EL: Leading edge erase Es: Side erase

The erase lamp unit consists of a row of 54 LEDs extending across the full width of the drum. In erase mode (center erase or side erase), the appropriate LEDs turn on in acco rda nce wit h th e m odes sel e cte d by the use r .

Detailed

Descriptions

STM 2-51 A156/A160/A162

5.2 LEADING EDGE AND TRAILING EDGE ERASE

The entire row of LEDs turns on when the main motor turns on. They stay on until the erase margin slightly overlaps the leading edge of the original image on the drum (leading edge erase margin). This prevents the shadow of the original’s leadi n g ed ge fr om ap pe ar i n g on the copy pa pe r . Thi s l ea din g ed ge erase margin is also necessary for the leading edge of the copy paper to separate from the hot roller.

When the scanner rea che s the re tu r n po si tio n, the drum charge roller and the exposure lamp tu r n of f. Ho weve r , th e charged length on the drum surface is a little longer than the actual original length to make sure that there is a complete image of the original.

The entire row of LEDs turn on when the trailing edge of the latent image has passed under the erase lamp unit. This prevents developing unnecessary parts of the drum surface, reducing toner consumption and the drum cleaning loa d.

The LEDs stay on to erase th e l ea din g ed ge of the latent image in the next copy cycle. After the final copy, the erase lamp s turn off at the same time as the main motor.

The leading and trailing edge margins can be adjusted with SP2-101-001 and SP2-101-002 respectively.

5.3 SIDE ERASE

Based on the combination of copy paper size and the reproduction ratio, the LEDs turn on in blocks. This prevents the shadow of the original side edge and the unexposed front and rear sides of the drum surface in reduction mode from being deve l op ed . Thi s r ed uce s ton er con sum p ti o n an d th e dr u m cleaning load.

A156/A160/A162 2-52 STM

GESTETNER 2635TD, 9035DL, A156, FT5535, 2635 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual