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IMPORTANT SAFETY NOTICES
PREVENTION OF PHYSICAL INJURY
1. Before disassembling or assembling parts of the copier and peripherals, make sure that the copier power cord is unplugged. 2. The wall outlet should be near the copier and easily accessible. 3. Note that some components of the copier and the paper tray unit are supplied with electrical voltage even if the main switch is turned off. 4. If any adjustment or operation check has to be made with exterior covers off or open while the main switch is turned on, keep hands away from electrified or mechanically driven components. 5. The inside and the metal parts of the fusing unit become extremely hot while the copier is operating. Be careful to avoid touching those components with your bare hands. 6.The copier is not attached to the table. Pushing the copier too heard may cause it to drop onto the floor. While moving the copier, push the table. 7. When the main switch is tuned on, the machine will suddenly start turning to perform the developer initialization. Keep hans away from any mechanical and electrical components during this period.
HEALTH SAFETY CONDITIONS
1. Never operate the copier without the ozone filters installed. 2. Always replace the ozone filters with the specified ones at the specified intervals. 3. Toner and developer are non-toxic, but if you get either of them in your eyes by accident, it may cause temporary eye discomfort. Try to remove with eye drops or flush with water as first aid. If unsuccessful, get medical attention.
OBSERVANCE OF ELECTRICAL SAFETY STANDARDS
1. The copier and its peripherals must be installed and maintained by a customer service representative who has completed the training course on those models.
CAUTION
2. The RAM board on the main control board has a lithium battery which can explode if replaced incorrectly. Replace the RAM board only with an identical one. The manufacturer recommends replacing the entire RAM board. Do not recharge or burn this battery. Used RAM board must be handled in accordance with local regulations.
SAFETY AND ECOLOGICAL NOTES FOR DISPOSAL
1. Do not incinerate the toner cartridge or the used toner. Toner dust may ignite suddenly when exposed to open flame. 2. Dispose of used toner, developer, and organic photoconductor according to local regulations. (These are non-toxic supplies.) 3. Dispose of replaced parts in accordance with local regulations. 4. When keeping used RAM boards in order to dispose of them later, do not put more than 100 RAM boards per sealed box. Storing larger numbers or not sealing them apart may lead to chemical reactions and heat build-up.
SECTION 1 OVERALL MACHINE INFORMATION
15 July 1996
SPECIFICATION
Configuration: Copy Process: Toner Supply Control: Photoconductor: Originals: Original Size: Original Alignment: Copy Paper Size:
Console Dry electrostatic transfer system Fuzzy Control OPC drum Sheet/Book Maximum A3/11" x 17"
Left rear corner Maximum Minimum A3/11" x 17" A5/51/2" x 81/2" (Tray) B5/81/2" x 11" (1.5 k LCT) A6/51/2" x 81/2" (By-pass) A3/11" x 17" A5/51/2" x 81/2" (sideways)
Duplex Copying: Copy Paper Weight:
Maximum Minimum
Paper tray: 52 ~ 128 g/m2, 14 ~ 34 lb Bypass feed table: 52 ~ 157 g/m2, 14 ~ 42 lb Duplex copying: 64 ~ 104 g/m2, 17 ~ 24 lb 4 Enlargement and 6 Reduction
A4/A3 Version 200% 141% 122% 115% 100% 93% 82% 75% 71% 65% 50% LT/LDG Version 200% 155% 129% 121% 100% 93% 85% 77% 74% 65% 50%
Reproduction Ratios:
Enlargement Full Size
Reduction
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Overall Information
1. SPECIFICATION
SPECIFICATION
15 July 1996
Power Source:
115 V, 60 Hz, more than 20 A (for N.A) 220 ~ 240 V, 50 Hz/60 Hz, more than 10 A (for Europe and Asia) A175 copier
Warm-up Stand-by Copying Maximum Copier only 1.20 kVA 0.22 kVA 1.40 kVA 1.70 kVA Full system* 1.22 kVA 0.24 kVA 1.40 kVA 1.75 kVA
Power Consumption:
A176/A191 copiers
Warm-up Stand-by Copying Maximum Copier only 1.20 kVA 0.22 KVA 1.50 kVA 1.70 kVA Full system* 1.22 kVA 0.24 kVA 1.50 kVA 1.75 kVA
A177/A192 copiers
Warm-up Stand-by Copying Maximum Copier only 1.20 kVA 0.22 kVA 1.60 kVA 1.70 kVA Full system* 1.22 kVA 0.24 kVA 1.60 kVA 1.75 kVA
*Full System:
· Mainframe with dual job feeder, floor type
sorter stapler and 3,500-sheet large capacity tray · Mainframe with recirculating document handler, finisher and 3,500-sheet large capacity tray
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15 July 1996
SPECIFICATION
A175 copier Sound pressure level
(The measurements are made according to ISO 7779 at the operator position.) Stand-by Copying Copier only less than 34 dB (A) less than 57 dB (A) (average)
Sound power level
(The measurements are made according to ISO 7779.) Stand-by Copying Copier only less than 48 dB (A) less than 70 dB (A) (average)
A176/A191 copiers Sound pressure level
(The measurements are made according to ISO 7779 at the operator position.) Stand-by Copying Copier only less than 34 dB (A) less than 59 dB (A) (average)
Sound power level
(The measurements are made according to ISO 7779.) Stand-by Copying Copier only less than 48 dB (A) less than 73 dB (A) (average)
A177/A192 copiers Sound pressure level
(The measurements are made according to ISO 7779 at the operator position.) Stand-by Copying Copier only less than 36 dB (A) less than 59 dB (A) (average)
Sound power level
(The measurements are made according to ISO 7779.) Stand-by Copying Copier only less than 50 dB (A) less than 73 dB (A) (average)
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Overall Information
Noise Emission:
Sound Pressure Level: The measurements are made according to ISO7779
SPECIFICATION
15 July 1996
Dimensions:
Copier only Copier with dual job feeder, sorter stapler, and 3,500-sheet large capacity tray Copier with dual job feeder, sorter stapler with punch, and 3,500-sheet large capacity tray Copier with recirculating document handler, finisher, and 3,500-sheet large capacity tray Width Depth Height 690 mm 690 mm 980 mm 27.2" 27.2" 38.6" 1,659 mm 690 mm 1,116 mm 65.4" 27.2 mm" 43.9" 1,659 mm 690 mm 1,113 mm 65.4" 27.2" 43.9 1,764 mm 690 mm 1,112 mm 65.9" 27.2" 43.8"
Weight:
Copier only: (Without the optional platen cover = Approximately 2 kg) A175 copier: Approximately 161 kg A176/A177 copiers: Approximately 164 kg A191/A192 copiers: Approximately 167 kg From 50% to 200% in 1% steps
A4/LT (sideways) 51 (A4 others) 50 (A4/in France) 50 (LT) 60 70 A3/DLT 26 31 36 B4/LG 32 38 44
Zoom: Copying Speed:
A175 copier A176/A191 copiers A177/A192 copiers
Warm-up Time:
Less than 5 minutes (20°C) (A175 copier) Less than 5.5 minutes (20°C) (A176/A177/A191/ A192 copiers) 3.1 seconds (A175 copier) 2.6 seconds (A176/A177/A191/A192 copiers)
First Copy Time: (A4/81/2: x 11" sideways from the 1st feed station) Copy Number Input: Manual Image Density Selection: Automatic Reset:
Number keys, 1 to 999 (count up or count down) 7 steps 1 minute standard setting; can also be set from 1 second to 999 seconds or no auto reset.
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15 July 1996
SPECIFICATION
· Paper tray: approximately 550 sheets · Tandem tray: approximately 500 sheets · Large capacity tray: approximately 1500
sheets Toner Replenishment: Optional Equipment: 1,100 g/cartridge
· Platen cover (A528-04) · Dual job feeder (A610) · Recirculating document handler (A607) · 20 bin sorter stapler (Floor type) (A606-17: · · · · ·
· ·
Ricoh, -22: NRG, -15: Savin, -26: Infotec) Finisher (A608) 3500-sheet Large capacity tray (A609) Receiving Tray (A446-05) Key Counter Bracket D (A509-03) 20 bin sorter stapler (Floor type) with punch (A606-57, -67: Ricoh, -52, -62: NRG -66: Infotec, -55: Savin) Guidance ROM KIT (A627) Editing sheet (spare part)
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Overall Information
Copy Paper Capacity:
· By-pass feed table: approximately 50 sheets
MACHINE CONFIGURATION
15 July 1996
2. MACHINE CONFIGURATION
2.1 COPIER OVERVIEW
There are three types of mainframe. A175 copier Four 550-sheet paper trays Optional 3,500-sheet large capacity tray
550 550 550 550
A176V500.img
(3,500)
A176/A177 (U.S.A., Asia) copiers Tandem paper tray (including two 500-sheet paper tray) One 550-sheet paper tray 1,500-sheet built-in large capacity tray Optional 3,500-sheet large capacity tray 500 x 2 or 500 550 (3,500)
1,500
A176V501.img
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15 July 1996
MACHINE CONFIGURATION
Tandem paper tray Three 550-sheet paper trays Optional 3,500-sheet large capacity tray
500 x 2 or 550 550 550 550
A176V500.img
(3,500)
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Overall Information
A191/A192 (Europe) copiers
MACHINE CONFIGURATION
15 July 1996
2.2 SYSTEM OVERVIEW
DJF version (Mainframe type (A175/A176/A177 (U.S.A.), A175/A191/A192 (EU)) with dual job feeder and floor type sorter stapler. The mainframe in the illustration below is the A176.) Dual job feeder (A610)
Floor type sorter stapler (A60617) or Floor type sorter stapler with punch (A60657, A60667)
A176V502.img
3,500-sheets large capacity tray (A609)
RDH version (The mainframe (A175/A176/A177 (U.S.A.), A175/A191/A192 (EU)) with recirculating document handler and finisher. The mainframe in the illustration below is the A176.) Recirculating document handler (A607)
Finisher (A608)
3,500-sheets large capacity tray (A609)
A176V503.img
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15 July 1996
MACHINE CONFIGURATION
MEMO
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Overall Information
COPY PROCESS AROUND THE DRUM
15 July 1996
3. COPY PROCESS AROUND THE DRUM
11 2 1 3 4 5 6
10
9
7 8
A176V504.wmf
1. OPC DRUM The organic photo conductive (OPC) drum (100 mm diameter) has high resistance in the dark and low resistance under light. 2. DRUM CHARGE In the dark, the charge corona unit gives a uniform negative charge to the OPC drum. The charge remains on the surface of the drum. The amount of negative charge on the drum is proportional to the negative grid bias voltage applied to the grid plate on the charge corona unit. 3. EXPOSURE An image of the original is reflected to the OPC drum surface via the optics section. The charge on the drum surface is dissipated in direct proportion to the intensity of the reflected light, thus producing an electrical latent image on the drum surface. The amount of charge remaining as a latent image on the drum depends on the exposure lamp intensity controlled by the exposure lamp voltage. 4. ERASE The erase lamp illuminates the areas of the charged drum surface that will not be used for the copy image. The resistance of drum in the illuminated areas drops and the charge on those areas dissipates.
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COPY PROCESS AROUND THE DRUM
6. DEVELOPMENT Positively charged toner is attracted to the negatively charged areas of the drum, thus developing the latent image. (The positive triboelectric charge of the toner is caused by friction between the carrier and toner particles.) The development bias voltage applied to the development roller shaft controls two things: 1) The threshold level if toner is attracted to the drum or toner remains on the development roller. 2) The amount of toner to be attracted to the drum. The higher the negative development bias voltage is, the less toner is attracted to the drum surface. 7. PRE-TRANSFER LAMP (PTL) The PTL illuminates the drum to remove almost all the negative charge from the exposed areas of the drum. This makes image transfer easier. 8. IMAGE TRANSFER Paper is fed to the drum surface at the proper timing so as to align the copy paper and the developed image on the drum surface. Then, a negative charge is applied to the reverse side of the copy paper by the transfer belt, producing an electrical force which pulls the toner particles from the drum surface onto the copy paper. At the same time, the copy paper is electrically attracted to the transfer belt. 9. PAPER SEPARATION Paper separates from the OPC drum by the electrical attraction between the paper and the transfer belt. The pick-off pawls help to separate the paper from the drum. 10. CLEANING The cleaning brush removes toner remaining on the drum after image transfer and the cleaning blade scrapes off all the remaining toner. 11. QUENCHING Light from the quenching lamp electrically neutralizes the charge potential of the drum surface.
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Overall Information
5. DRUM POTENTIAL SENSOR The drum potential sensor detects the electric potential on the drum to compensate image processing elements.
MECHANICAL COMPONENT LAYOUT
15 July 1996
4. MECHANICAL COMPONENT LAYOUT
3 4 5 6 7 8 9 10 11
2
12 13 14
1 39 38 37
15 16 17 18 19 20
36
21 22 23
35
24 25 26 27 40
28 34 33 32 31 30 29
A176V505.wmf
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15 July 1996
MECHANICAL COMPONENT LAYOUT
1. 3rd Mirror 2. 2nd Mirror 3. 1st Mirror 4. Exposure Lamp 5. Lens 6. Cleaning Brush 7. Cleaning Blade 8. Quenching Lamp 9. Charge Corona Unit 10. OPC Drum 11. 6th Mirror 12. 4th Mirror 13. 5th Mirror 14. Erase Unit 15. Drum Potential Sensor 16. Toner Hopper 17. Development Unit 18. Pre-Transfer Lamp 19. Pick-up Roller 20. Feed Roller 21. Separation Roller
22. Registration Rollers 23. Transfer Belt 24. Vertical Transport Rollers 25. Tandem Tray 550-sheet Tray 26. Universal Tray 27. 1500-sheet LCT 550-sheet Tray 28. Toner Collection Bottle 29. Transfer Belt Cleaning Blade 30. Hot Roller 31. Pressure Roller 32. Jogger Fences 33. Duplex Positioning Roller 34. Duplex Pick-up Roller 35. Duplex Feed Roller 36. Separation Belt 37. Junction Gate 38. Exit Rollers 39. Optics Cooling Fan 40. 550-sheet Tray
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Overall Information
DRIVE LAYOUT
15 July 1996
5. DRIVE LAYOUT
9 10 11 1
2
8 7
3 4 5
6
A176V506.wmf
Main Motor Scanner Drive Motor Fusing/Duplex Drive Motor Paper Feed Motor Toner Collection Motor Registration Clutch By-Pass Feed Motor BY-Pass Feed Clutch Development Drive Motor
1. OPC Drum 2. Scanner Unit 3. Transfer Belt Unit 4. Paper Exit Unit 5. Fusing Unit 6. Duplex Unit 7. Paper Trays 8. Paper Feed Units 9. Toner Hopper 10. Development Unit 11. Cleaning Unit
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PAPER PATH
6.1 STANDARD COPYING
[F] [D]
[C] [B] [A] [E] [A]
A176V507.wmf
Paper feed begins from the exterior LCT, by-pass feed table or paper feed stations in the paper tray unit. The copy paper then follows one of two paths inside the copier. The path followed depends on which mode the operator has selected. For copy processing, all sheets follow the same paths from the paper feed mechanism [A] through the registration rollers [B], transfer belt [C], and fusing unit [D]. After that, copies are delivered to the sorter bins [E] or proof tray [F], however, 2 sided copies are diverted for further processing.
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Overall Information
6. PAPER PATH
PAPER PATH
15 July 1996
6.2 MULTIPLE 2-SIDED COPYING
a. Front Side [D] [A] [C]
[B]
A176V508.wmf
b. Rear Side
A176V509.wmf
In this mode the junction gate [A] directs sheets exiting the fusing unit to the duplex tray entrance. After that, all sheets follow the path through the duplex entrance rollers [B]. After all front side copying is completed, the sheets on the duplex tray are fed in order from the bottom to the top and follow the path through the duplex feed mechanism and vertical transport rollers [C] to the registration rollers [D]. After that, these sheets follow the same path as standard copying from the registration rollers to the sorter.
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15 July 1996
ELECTRICAL COMPONENT DESCRIPTION
Refer to the electrical component layout on the reverse side of the attached Point to Point for symbols and index numbers.
Symbol Motors M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M11 M12 M13 M14 M15 M16 M17 M18 M19 M20 M21 Lens Horizontal Drive Lens Vertical Drive Optic Cooling Fan Fusing/Duplex Drive Paper Feed 1st Lift 2nd Lift Toner Collection 3rd Lift (4 Tray version only) Side Fence Drive (Tandem version only) Rear Fence Drive (Tandem version only) Scanner Drive Exhaust Fan Main Development Drive By-pass Feed 3rd Scanner Drive Toner Bottle Drive Charge Wire Cleaner Drive Jogger Drives the 1st and 2nd scanners (dc servo). Removes the heat from around the fusing unit. Drives the main unit components. Drives the development unit. Drives the by-pass feed rollers. Drives the 3rd scanner (dc stepper) Rotates the toner bottle to supply toner to the toner hopper. Drives the main charge wire cleaner to clean the charge wire. Drives the jogger fences to square the paper stack in the duplex tray (dc stepper). Shifts the lens horizontal position. Shifts the lens vertical position. Removes heat from the optics unit. Drives the fusing unit, the duplex unit, and the paper exit rollers. Drives all feed and transport rollers in the paper tray unit. Raises the bottom plate in the 1st paper tray. Raises the bottom plate in the 2nd paper tray. Transports the collected toner to the toner collection bottle. Raises the bottom plate in the 3rd paper tray. Opens and closes the front and the rear side fences of the tandem tray. Moves the papers stacked in the left tandem tray to the right tandem tray. 42 43 44 45 46 47 48 49 50 51 52 53 54 90 91 92 93 94 95 96 127 Name Function Index No.
LCT Motor Lifts and lowers the LCT bottom plate (1,500 Tray version only) to bring paper to the feed position and allow loading of the paper.
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Overall Information
7. ELECTRICAL COMPONENT DESCRIPTION
ELECTRICAL COMPONENT DESCRIPTION
15 July 1996
Symbol M22 M23 M24 M25 M26
Name
Function
Index No. 141 142 *143A, B 144 151
AC Drive Cooling Fan Remove heat from around the AC (60/70 CPM version only) drive unit. Optic Cooling Fan-2 Remove heat from the optic unit. (60/70 CPM version only) Duplex Cooling Fan Drum Cooling Fan (70 CPM version only) 4th Lift (4 Tray version only) Cools the paper on the duplex tray to reduce the heat around the drum. Cools the drum unit to remove the heat from the duplex tray. Raises the bottom plate in the 4th paper tray.
* (A: 60/70 CPM, B: 50/51 CPM) Magnetic Clutches MC1 MC2 MC3 MC4 MC5 MC6 MC7 MC8 MC9 Duplex Feed 1st Feed 2nd Feed 3rd Feed 4th Feed (4 Tray version only) Toner Supply Registration By-pass Feed Duplex Transport Turns the toner supply roller to supply toner to the development unit. Drives the registration rollers. Starts paper feed from the by-pass feed table. Drives the duplex transport rollers to transport the paper to the vertical transport rollers. Starts paper feed from the duplex tray to the duplex transport rollers. Starts paper feed from the 1st feed tray. Starts paper feed from the 2nd feed tray. Starts paper feed from the 3rd feed tray. Starts paper feed from the 4th feed tray. 57 58 60 64 65 99 101 104 152
Switches SW1 SW2 SW3 SW4 SW5 By-pass Table Front Door Safety 1st Tray Set (Non-Tandem version only) 2nd Paper Size Toner Overflow Detects if the by-pass feed table is open or closed. Cuts the ac power line and detects if the front door is open or not. Detects if the 1st tray is set or not. 66 Determines what size paper is in the 2nd (universal) paper tray. Detects when the toner collection bottle is full. 67 75 25 29
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15 July 1996
ELECTRICAL COMPONENT DESCRIPTION
SW6 SW7 SW8 SW9 SW10 SW11
Toner Collection Bottle Set 3rd Tray Set (4 Tray version only) Main
Detects if the toner collection bottle is set or not. Detects if the 3rd tray is set or not. Provides power to the copier
77 83 84 122 126 149
Lower Front Door Safety Detects if the front door is open or not.
Tray Down Lowers the LCT bottom plate. (1500 Tray version only) 4th Tray Set (4 Tray version only) Detects if the 4th tray is set or not.
Solenoids Junction Gate SOL1 SOL2 SOL3 SOL4 SOL5 SOL6 SOL7 1st Pick-up SOL8 1st Separation Roller SOL9 2nd Pick-up SOL10 2nd Separation Roller SOL11 3rd Pick-up SOL12 Duplex Positioning By-pass Pick-up Guide Plate Moves the junction gate to direct copies to the duplex tray or to the paper exit. Controls the up-down movement of the positioning roller. Controls the up-down movement of the pick-up roller for by-pass feed. Opens the guide plate when a paper misfeed occurs around this area. 55 56 59 61 62 63 97
Transfer Belt Positioning Controls the up-down movement of the transfer belt unit. Pressure Arm Tandem Lock Presses the paper on the duplex tray against the duplex feed rollers. Locks the left tandem feed tray and separates the right and left tandem trays. Controls the up-down movement of the pick-up roller in the 1st feed station. Controls the up-down movement of the separation roller in the 1st feed station. Controls the up-down movement of the pick-up roller in the 2nd feed station. Controls the up-down movement of the separation roller in the 2nd feed station. Controls the up-down movement of the pick-up roller in the 3rd feed station.
98
100
102
103
105
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Overall Information
Symbol
Name
Function
Index No.
ELECTRICAL COMPONENT DESCRIPTION
15 July 1996
Symbol SOL13
Name 3rd Separation Roller
Function Controls the up-down movement of the separation roller in the 3rd feed station. Controls the up-down movement of the pick-up roller in the 4th feed station. Controls the up-down movement of the separation roller in the 4th feed station.
Index No. 106
SOL14
4th Pick-up (4 Tray version only) 4th Separation Roller (4 Tray version only)
153
SOL15
154
Sensors S1 S2 Platen Cover Position-2 S3 S4 S5 S6 S7 S8 S9 S10 Duplex Exit S11 Lens Vertical HP Lens Horizontal HP 3rd Scanner HP By-Pass Paper End Guide Plate Position Jogger HP Vertical Transport Scanner HP Platen Cover Position-1 Informs the CPU when the 1st and 2nd scanners are at the home position. Informs the CPU that the platen cover is in the up or down position (related to APS/ARE function). Informs the CPU that the platen cover is in the up or down position to detect if the original has been removed or not. Informs the CPU that the lens is at the full-size position. Informs the CPU that the lens is at the horizontal home position. Informs the CPU when the 3rd scanner is at the home position. Informs the CPU that there is no paper in the by-pass feed table. Informs the CPU if the registration guide plate is closed or not. Detects if the duplex jogger fences are at the home position or not. Detects the leading edge of the paper to determine the paper feed timing of the next sheet. Detects the leading edge of the paper to determine the duplex transport clutch on timing. 1 2
3 4 5 6 7 8 9 10
11
S12 S13 S14 S15
Duplex Entrance Sensor Detects the leading edge of the paper to determine the duplex feed clutch off timing. Duplex Paper End Duplex Transport Detects paper in the duplex tray. Detects the leading edge of the paper to control the jogger motor and the positioning solenoid on timing. Detects misfeeds.
12 13 14 15
Exit
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15 July 1996
ELECTRICAL COMPONENT DESCRIPTION
S16 S17 S18 S19 S20 S21 S22 S23 S24 S25 S26 S27 S28 S29 S30 S31 S32 S33 S34 S35 S36 S37 S38 S39
Fusing Exit Paper Guide Auto Image Density Original Length-1 Original Length-2 Original Width By-Pass Paper Size Toner Density Registration Toner Near End Auto-Response Drum Potential Image Density 1st Paper End 1st Paper Near End 1st Paper Feed
Detects misfeeds. Detects misfeeds. Senses the background density of the original. Detects original length. Detects original length. Detects original width. Informs the CPU what size paper is in the by-pass feed table. Senses the amount of toner in the black developer. Detects misfeeds and controls registration clutch off-on timing. Detects toner end condition. Returns the display from the screen saver. Detects the drum surface potential. Detects the density of the ID sensor pattern on the drum. Informs the CPU when the 1st cassette runs out of paper. Informs the CPU when the 1st cassette is in near end condition. Controls the 1st paper feed clutch off/on timing and the 1st pick-up solenoid off timing. Informs the CPU when the 2nd cassette is in near end condition. Detects the correct feed height of the 1st cassette. Informs the CPU when the 2nd cassette runs out of paper. Detects the toner collection motor operation. Detects the correct feed height of the 2nd cassette. Detects the correct feed height of the 3rd cassette. Informs the CPU when the 3rd cassette is in near end condition. Informs the CPU when the 3rd cassette runs out of paper.
16 17 20 21 22 23 26 27 28 30 34 39 41 68 69 70 71 72 73 74 76 78 79 80
2nd Paper Near End 1st Lift 2nd Paper End Toner Collection Motor 2nd Lift 3rd Lift 3rd Paper Near End (4 Tray version only) 3rd Paper End
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Overall Information
Symbol
Name
Function
Index No.
ELECTRICAL COMPONENT DESCRIPTION
15 July 1996
Symbol S40
Name 3rd Paper Feed
Function Controls the 3rd paper feed clutch off/on timing and the 3rd pick-up solenoid off timing. Controls the 2nd paper feed clutch off/on timing and the 2nd pick-up solenoid off timing. Detects when the bottom plate is completely lowered to stop the 1st lift motor. Informs the CPU when the tandem tray side fences are open. Informs the CPU when the tandem tray rear fence is in the return position. Informs the CPU when the tandem tray rear fence is in the home position. Informs the CPU when the left tandem tray runs out of paper.
Index No. 81
2nd Paper Feed S41 Base Plate Down (Tandem version only) Side Fence Positioning (Tandem version only) Rear Fence Return (Tandem version only) Rear Fence HP (Tandem version only) Left Tandem Paper End (Tandem version only)
82
S42 S43 S44 S45 S46 S47 S48 S49 S50 S51 S52 S53 S54
85 86 87 88 89 123 124 125 150 145 146 147 148
LCT Near End Detects the paper near end condition. (1,500 Tray version only) Tray Down Detects when the tray is completely (1,500 Tray version only) lowered to stop the LCT motor. Tray Paper Set Informs the CPU when the paper is (1,500 Tray version only) set on the LCT bottom tray. Side Fence Close (Tandem version only) 4th Lift (4 Tray version only) 4th Paper Near End (4 Tray version only) 4th Paper End (4 Tray version only) 4th Paper Feed (4 Tray version only) Detects whether the side fence close or not. Detects the correct feed height of the 4th cassette. Informs the CPU when the 4th cassette is in near end condition. Informs the CPU when the 4th cassette runs out of paper. Controls the 4th paper feed clutch off/on timing and the 4th pick-up solenoid off timing.
PCBs PCB1 PCB2 PCB3 PCB4 PCB5 AC Drive Main Optic Control Development Bias Control Paper Feed Control Provides AC power to the exposure lamp and fusing lamp. Controls all machine functions. Controls all optics components. Controls the output of development bias. Controls all components in the paper bank. 108 109 110 111 112
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ELECTRICAL COMPONENT DESCRIPTION
PCB6 PCB7 PCB8
DC Power Supply Unit Guidance Operation Panel
Provides DC power. Controls the guidance display. Controls the LED matrix, and monitors the key matrix.
113 120 121
Lamps L1 L2 L3 L4 L5 Exposure Fusing Quenching Erase Pre-transfer Applies high intensity light to the original for exposure. Provides heat to the hot roller. Neutralizes any charge remaining on the drum surface after cleaning. Discharges the drum outside the image area. Reduces the charge on the drum surface before transfer. 18 32 37 38 40
Power Packs Transfer PP1 Charge PP2 Provides high voltage for the transfer belt and controls the transfer belt positioning solenoid. Provides high voltage for the charge corona wires, and the grid plate. Controls QL, PTL, and charge wire cleaner motor functions. 117
119
Others TS1 TF1 TH1 TH2 TH3 Optics Thermoswitch Fusing Thermofuse Fusing Thermistor Optics Thermistor Drum Thermistor (Located on the ID Sensor Ass'y) Transfer Anti-Condensation Opens the exposure lamp circuit if the optics unit overheats. Opens the fusing lamp circuit if the fusing unit overheats. Senses the temperature of the hot roller. Monitors the temperature of the optics cavity. Monitors the temperature of the OPC drum. Turns on when the main switch is off to prevent moisture from forming on the transfer belt. 19 33 24 36 41
H1
31
H2 RA1
Optics Anti-Condensation Turns on when the main switch is off to prevent moisture from forming on the optics. Main Power Relay Controls main power.
35 107
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Overall Information
Symbol
Name
Function
Index No.
ELECTRICAL COMPONENT DESCRIPTION
15 July 1996
Symbol CO1 NF1 CB1 LA1
Name Total Counter Noise Filter Circuit Breaker
Function Keeps track of the total number of copies made. Removes electrical noise. Provides back-up high current protection for the electrical components. Removes current surges from the AC input lines.
Index No. 114 115 116 118
Lightening Arrestor
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SECTION 2 DETAILED SECTION DESCRIPTIONS
15 July 1996
PROCESS CONTROL
1. PROCESS CONTROL
1.1 OVERVIEW
Original Scale
Image Density Control (Fuzzy Control) Latent Image Control
ADS Pattern
VD Pattern
VL Pattern VD Pattern VL Pattern Original Exposure Glass
Latent image Control
Exposure Control Charge Control
Lamp Voltage
Grid Voltage QL
Erase Lamp Drum Potential Sensor
Toner Supply On time Development. Bias Drum Thermistor Paper TD Sensor
ID Sensor
Image Density Control (Fuzzy Control)
Main PCB
Toner Supply Control
A176D500.wmf
This model uses two process control methods. One compensates for variation in the drum potential (latent image control) and the other controls the toner concentration and toner supply amount (image density control).
2-1
Detailed Descriptions
PROCESS CONTROL
15 July 1996
1.1.1 Latent Image Control
QL Charge Exposure Black White Erase Potential Sensor VD VL VR
Vo
Drum
A176D501.wmf
The figure shows the changes of the drum potential during the copy process. VO: VD (Dark Potential): VL (Light Potential): VR (Residual Voltage): The drum potential just after charging the drum. The drum potential just after exposing the black pattern (VD pattern) The drum potential just after exposing the white pattern (VL pattern) The drum potential just after the exposure of the erase lamp.
After long usage following installation or a PM, drum potential will gradually increase due to the following factors: Dirty optics or exposure lamp deterioration Dirty charge corona casing and grid plate Change of the drum sensitivity In this copier, the change in drum potential is detected by the drum potential sensor and the following items are controlled to maintain good copy quality. The grid bias voltage The exposure lamp voltage The development bias voltage. A drum thermistor detects the drum temperature and this data is also used to control the above voltages. It is impossible to explain simply because it is controlled by methods developed in our laboratories using an artificial neural network.
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15 July 1996
PROCESS CONTROL
1.1.2 Image Density Control Image density is controlled by the following sensors: Toner density sensor (TD sensor)
Detailed Descriptions
Image density sensor (ID sensor) Data from the TD sensor is 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 of toner chargeability (influenced by the environment) even if the toner concentration is constant. By the ID sensor compensation, toner concentration is changed to keep the image density on the OPC drum constant. The following items are controlled to maintain a constant copy image density: Toner supply clutch on time Toner supply level data (VREF) of the TD sensor
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PROCESS CONTROL
15 July 1996
1.2 PROCESS CONTROL DATA INITIAL SETTING
The following flow chart shows all the steps that will be performed whenever the machine is turned on while the hot roller temperature is below 100°C. This initializes all the process control settings. Main SW On (Fusing Temp. < 100°C)
Charge wire cleaning (if more than 5 k copies are made since last cleaning)
Drum Potential Sensor Calibration
x
Drum Conditioning Start (Fusing Temp. = 180°C)
VSG Adjustment
Transfer belt voltage detection
VR Measurement
VD/VL Correction
TD Sensor Detection
y
ID Sensor Detection/Correction
z
ADS Adjustment
x : See Latent Image Control section
(Page 2-5) for details.
y : See Image Density Control section z
(Page 2-12) for details. : See Optics section (Page 2-39) for details.
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15 July 1996
PROCESS CONTROL
1.3 LATENT IMAGE CONTROL
1.3.1 Drum Potential Sensor Calibration
Case Sensor Output Amp. Drum
A176D503.wmf
[B]
Main PCB
A176D502.wmf
The drum potential sensor [A] is located just above the development unit. The sensor has a detector which detects the strength of the electric field from the electric potential on the drum. The output of the sensor depends on the strength of the electric field. Since the output of the sensor is affected by environmental conditions, such as temperature and humidity, the sensor output is calibrated during process control data initial setting. The High Voltage Control PCB [B] has two relay contacts. Usually RA602 grounds the drum. However, during the initial setting, the main PCB turns RA601 on and RA602 off and applies the voltage to the drum shaft. By measuring the output of the drum potential sensor when 100 V and 800 V are applied to the drum, the sensor output is calibrated automatically. (The machine recognizes the relationship between actual drum potential and the potential sensor output.)
2-5
Detailed Descriptions
[A]
PROCESS CONTROL
15 July 1996
1.3.2 Drum Conditioning When the fusing temperature reaches 180°C, the machine starts the drum conditioning process. In this mode, the main motor, main charge corona, erase lamp and development bias are activated for about 30 seconds and drum sensitivity and residual voltage (VR) are stabilized, as in continuous copy runs. 1.3.3 VSG Adjustment During drum conditioning, the ID sensor checks the bare drum's reflectivity and calibrates the output of the ID sensor to 4 ± 0.2 V. 1.3.4 VR Measurement
[V] VO VD New Drum Used Drum
Drum Potential
VL
Dark
Original Density
VR Light
A176D504.wmf
The above figure shows the relationship between the drum potential and the original density. To get constant copy quality, this relationship must be maintained. Since this relationship tends to change to the one represented by the dotted line by various factors, compensations are required. The residual voltage (VR) cannot be compensated even if the exposure lamp voltage is increased. Therefore, the VR change has to be compensated by other means. The main control board checks the drum potential just after the erase lamp exposure by the drum potential sensor after drum conditioning. This measured drum potential is in fact VR. This VR is used as the standard for the VD and VL corrections. NOTE: In the figure above, the residual voltage (VR) for the new drum is 0 V. Actually, there is some residual voltage even on the new drum.
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15 July 1996
PROCESS CONTROL
1.3.5 VD Correction
Exposure VD Pattern [V] VD
A176D505.wmf
Glass
Detailed Descriptions
VR VD Compensated Drum Potential 770 After many copies New Drum Dark Original Density Light
A176D506.wmf
VR
The drum potential just after the black pattern (VD Pattern) is exposed (VD: Dark Potential) tends to lower during drum life due to a decrease in the drum's capacity to carry a charge. To check the actual VD, the first scanner moves to the home position and the VD pattern (Black) stuck on the bottom side of the exposure glass bracket is exposed on the drum. The main control board measures VD through the drum potential sensor and adjusts it to a target value by adjusting the grid bias voltage (VGRID). On the other hand, there is a change of the drum residual voltage (VR), so that the target VD voltage is compensated as follows: Target VD Value: VD = VR + (770) The adjusted grid bias voltage (VGRID) is kept in memory until the next process control data initial setting.
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PROCESS CONTROL
15 July 1996
1.3.6 VL Correction
Exposure Glass [V] VL Pattern VD VR Drum Potential 770 VR 140 Dark Original Density VR Light
A176D507.wmf
Only VD Compensated VD and VL Compensated New Drum
A176D505-2.wmf
VL
Dirty optics and/or exposure lamp deterioration decreases the intensity of the light that reaches the drum. In addition to this, the drum sensitivity also changes during the drum's life. These factors change the drum potential just after white pattern exposure (VL: Light Potential). To check the actual VL, the lens moves to the VL pattern check position. The VL pattern (White) stuck underneath the original scale is exposed on the drum. The main control board measures VL through the drum potential sensor and adjusts it to a target value by adjusting the exposure lamp voltage (VLAMP). The residual voltage (VR) change also affects VL, so that VL's target voltage is compensated as follows: Target VL Value: VL = VR + (140) The adjusted exposure lamp voltage (VLAMP) is stored in memory until the next process control data initial setting.
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15 July 1996
PROCESS CONTROL
1.3.7 VR Correction [V] VD VR Drum Potential 770 VR 140 Dark Original Density
Detailed Descriptions
VL
Development Bias (VBB) VD and VL Compensated New Drum
VR Light
A176D508.wmf
Potentials (VR, VD, VL) are monitored by the potential sensor. (This is done only when the fusing temperature is less than 100°C after the machine is turned on.) During the check cycle, the VD and VL patterns are exposed and the drum potential on the area where exposed by each pattern is checked by the potential sensor. Compare the curve of the VD and VL compensated drum potential with the curve of the new drum, they are parallel but the compensated potential is still higher (VR) than the new drum potential. To prevent dirty backgrounds due to increased residual potential, development bias (VBB) is applied as follows: VBB= VR + (220)
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PROCESS CONTROL
15 July 1996
1.3.8 Initial Setting Sequence The following graph shows the sequence of events during process control data initial setting. for the purpose of ADS sensor correction Exposure Lamp V800 VD New VD
Potential Sensor Output
V100 VR
VL New VR
New VL
1. Potential sensor
2. VR', VD', VL' potential Latent Image Control
3. VD, VL correction
4. ID sensor pattern potential
A176D509.wmf
1. Potential sensor calibration By measuring the output of the drum potential sensor when 100 V and 800 V are applied to the drum, the sensor output (V100 and V800) is calibrated automatically (See page 2-5 for details). 2. VR, VD, VL potential detection After about 30 seconds of drum conditioning, VD and VL Patterns are developed by using the previous grid bias voltage (VGRID) data and exposure lamp voltage (VLAMP) data to detect the VR, VD, VL data. The machine calculates the new VGRID and VLAMP data using the detected VR, VD, VL data.
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PROCESS CONTROL
3. VD and VL corrections Using the calculated VGRID and VLAMP data, VR, VD, and VL patterns are developed again and the new VR, VD, and VL data are detected. If both VD and VL data are within specifications, the new VGRID, VLAMP and development bias (VBB) are determined based on the new VD, VL, and VR values. Specifications: VD = 770 + VR ± 20 V VL = 140 + VR ± 20 V If VD is outside specifications, VGRID is shifted one step. Then the VD pattern is measured again and VD is detected again. The same is done for VL and VLAMP. The above process continues until both VD and VL fall within specifications. The graph on the previous page shows the example when only VL was outside specifications at the first VL detection and it became within specifications after one VL correction (VLAMP is changed 0.5V/step , VGRID is changed 20V/step). If V100 or V800 at drum potential sensor calibration is outside specifications or if VD or VL do not fall within specifications after VGRID or VLAMP are shifted to the maximum or minimum level, the machine stops VD or VL correction and uses the previous VGRID and VLAMP values during copying. In this case, nothing is indicated on the machine but the SC counter is incremented. Related SC codes (see troubleshooting section for details):
Code 361 364 365 366 Condition Incomplete drum potential sensor calibration Abnormal VD detection Abnormal VL detection VR abnormal
Development bias is also decided by using VR as follows. VBB = VR + (220) 4. ID sensor pattern potential detection This is performed to determine ID Sensor Bias Voltage. The details are explained in the development control section (see page 2-16).
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Detailed Descriptions
PROCESS CONTROL
15 July 1996
1.4 IMAGE DENSITY CONTROL
1.4.1 Toner Density Sensor
A: VOUT (Gain data) is high. B: VOUT is within the specification. C: VOUT (Gain data) is low.
VIN
Main PCB VOUT AGC VD (12 V) GND Sensor Output TD Sensor
VOUT = VIN x
Gain 256 Gain = 12 x 256
A176D531.wmf
A176D510.wmf
Developer consists of carrier particles (iron) and toner particles (resin and carbon). Inside the development unit, developer passes through a magnetic field created by coils inside the toner density sensor. When the toner concentration changes, the voltage output by the sensor changes accordingly. When new developer with the standard toner concentration (2.0% by weight, 20 g of toner in 1000 g of developer) is installed, developer initial setting must be performed by using SP mode ( SP Adjustment - PAGE 1). During this setting, the output voltage (VOUT) from the auto gain control circuit (AGC) on the main control board PCB varies to change the output voltage from the toner density (TD) sensor. This is done by changing the gain data, see below. VOUT = VIN x Gain Data Gain Data = 12 x 256 256
If the data is high, VOUT becomes high, and the sensor output voltage becomes high. As a result, the sensor characteristic becomes as illustrated by curve A. If the data is low, VOUT becomes low, and the sensor output voltage becomes low. As a result, the sensor characteristic shifts as illustrated by curve C.
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PROCESS CONTROL
By selecting the proper gain data, the sensor output is set within the targeted control level (VREF, VREF = 2.5 ± 0.1 V). Now, the sensor characteristic is illustrated by curve B and the TD sensor initial setting is completed. The selected gain data is stored in memory, and VOUT from the auto gain control circuit stays constant during the toner sensor detection cycle. At every copy cycle, toner density in the developer is detected once. The sensor output voltage (VTD) during the detection cycle is compared with the toner supply level voltage (VREF).
Detailed Descriptions
A176D511.wmf
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PROCESS CONTROL
15 July 1996
To stabilize toner concentration, toner supply amount (toner supply clutch on time) is controlled by referring to VREF and VTD. The toner supply amount is calculated at every copy. The toner supply amount is determined by using the following factors.
x VREF VTD y VREF VTD'
(VTD' = VTD of the previous copy cycle)
A176D512.wmf
By referring to these factors, the machine recognizes the difference between the current toner concentration and the target toner concentration. The machine also understands how much toner concentration has changed and predicts how much the toner supply amount will probably change. By changing the toner supply amount precisely, toner concentration (image density) is kept at a constant level. Since the toner supply clutch on time updating is under fuzzy control, the relation among VTD, VTD', VREF cannot be expressed by a simple algebraic formula. The image on the OPC drum changes due to variation of toner chargeability (influenced by the environment) even if the toner concentration is constant. The image density sensor (ID sensor) directly checks the image on the OPC drum and shifts VREF data (under fuzzy control) to keep the image on the OPC drum constant, as explained in the next section. NOTE: 1) Toner end condition is detected by the toner end sensor (see the development section for details). 2) The toner supply clutch turns on at the intervals between each copy process while image development is not performed.
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15 July 1996
PROCESS CONTROL
1.4.2 Image Density Sensor Detection [B] [C]
Drum [A]
Detailed Descriptions
A176D514.wmf
bias
A176D513.wmf
VSG and VSP are checked by the ID sensor [A]. The ID sensor is located underneath the drum cleaning section. There is no ID sensor pattern in the optics, however, a pattern image is made on the OPC drum by the charge corona unit [B] and the erase lamp [C]. VSG is the ID sensor output when checking the erased drum surface. VSP is the ID sensor output when checking the ID sensor pattern image. To compensate for any variation in light intensity from the sensor LED, the reflectivity of both the erased drum surface and the pattern on the drum are checked.
VSP Detection
VSP Detection
VSP Detection
1st Series of
2nd Series of Copies
3rd Series of Copies
VSG Detection
Copies (8 copies)
VSG Detection
(5 copies)
VSG Detection
(17 copies)
VSG Detection
A176D515.wmf
VSG is detected every time the machine starts copying. During VSG detection, the development sleeve rollers do not rotate and no development bias is applied. VSP is detected after copying is completed if 10 or more copies have been made since VSP was last detected. Since the transfer belt must be released when checking VSP, a VSP check cannot be done during continuous copying.
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PROCESS CONTROL
15 July 1996
x Potential
Sensor Detection
VP
700 V
x
VP
y z
300 VIDB = VP +300 (V)
y ID Sensor
Bias Level
4.0 V
z ID Sensor
Output
VSP
A176D517.wmf A176D516.wmf
While developing the ID sensor pattern, ID sensor bias is applied. ID sensor bias is determined during process control data initial setting as follows: Apply charge while grid voltage is 700 V to create the ID sensor pattern. Check the drum potential (VP) of the latent image created by the charge with 700 V grid. Adjust the ID sensor bias (VIDB) so that it satisfies the following formula. VIDB = VP (300) (V) = VP + 300 (V) Change the bias to the calculated VIDB and detect VSP. VSG detected during VSG adjustment sequence in the process control data initial setting and VSP are used to determine VREF data at process control data initial setting. VIDB is not changed until the next process control data initial setting is done. After the series of copies is completed in the case that 10 or more copies have been made, VREF is updated by referring to the previous VREF (VREF'), VSG, VSP and the current TD sensor output (VTD). Since this VREF data updating is under fuzzy control, the relationship among VREF, VREF', VSG, VSP and VTD cannot be expressed by a simple algebraic formula. VREF is updated not only at the above case. But also during developer initial setting and during process control data initial setting.
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PROCESS CONTROL
1.4.3 Sensor Abnormal Conditions a. ID sensor (VSG,VSP) abnormal Whenever VSG falls under 2.5 V or VSP rises over 2.5 V, the CPU fixes the VREF data and toner concentration is controlled only by using TD sensor output. VSG and VSP are still detected as usual during abnormal conditions and if output returns to normal levels (VSG 2.5 V, VSP 2.5 V), the CPU returns the toner concentration control to normal mode. b. TD sensor (VTD) abnormal Whenever VTD rises over 4.0 V or VTD falls under 0.5 V, the CPU shifts the toner supply to the fixed supply mode. In this condition, the CPU never stops the toner supply. The fixed toner supply amount can be changed in four steps (4%, 7%, 11%, 14%) by using SP mode. The default fixed toner supply amount is 4%. VTD is still detected as usual during the abnormal condition and if its output returns to a normal level, the CPU returns the toner concentration control to normal mode. c. Drum Potential Sensor abnormal Whenever V100 rises over 0.7 V or V100 falls under 0.1 V or whenever V800 rises over 4.2 V or V800 falls under 2.7 V, the CPU also shifts the toner supply to the fixed supply mode, as for a TD sensor (VTD) abnormal condition. Related SC codes. (See troubleshooting section of details.):
Code 351 352 353 354 355 356 357 358 361 Condition Abnormal VSG Detection (VSG > 4.2 V) Incomplete TD Sensor Initial Setting Abnormal VSP Detection (VSP > 2.5 V) Abnormal VSG Detection (VSG 2.5 V) Abnormal VTD Detection (VTD > 4 V) Abnormal VTD Detection (VTD < 0.5 V) Abnormal VSP/VSG Detection (VSP/VSG 0.25) Abnormal VSP/VSG Detection (VSP/VSG < 0.025) Incomplete Drum Potential Sensor Calibration
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Detailed Descriptions
DRUM UNIT
15 July 1996
2. DRUM UNIT
2.1 OVERVIEW
12 13 14 15 16 1 2 3 4
11 5 10 9 7. 8 6
A176D518.wmf
The drum unit consists of the components as shown in the above illustration. An organic photoconductor drum (diameter: 100 mm) is used for this model. 1. OPC Drum 2. OPC Drum Protective Shutter 3. Erase Lamp 4. Drum Potential Sensor 5. Pre-transfer Lamp 6. Pick-off Pawl 7. Image Density Sensor 8. Drum Thermistor 9. Cleaning Brush 10. Toner Collection Coil 11. Cleaning Blade 12. Ozone Filter 13. Cleaning Filter 14. Charge Power Pack 15. Quenching Lamp 16. Main Charge Corona Unit
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DRUM UNIT
2.2 OPC DRUM CHARACTERISTICS
An OPC has the characteristics of: 1. Being able to accept a high negative electrical charge in the dark. (The electrical resistance of a photoconductor is high in the absence of light.)
Detailed Descriptions
2. Dissipating the electrical charge when exposed to light. (Exposure to light greatly increases the conductivity of a photoconductor.) 3. Dissipating an amount of charge in direct proportion to the intensity of the light. That is, where stronger light is directed to the photoconductor surface, a smaller voltage remains on the OPC. 4. Being less sensitive to changes in temperature (when compared to selenium F type drums). 5. Being less sensitive to changes in rest time (light fatigue). This makes it unnecessary to compensate development bias voltage for variations in rest time.
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DRUM UNIT
15 July 1996
2.3 DRUM CHARGE
2.3.1 Overview [A]
A176D519.wmf
This copier uses a double corona wire scorotron system for drum charge. Two corona wires are required to give sufficient negative charge on the drum surface because of a rather high drum speed (330 mm/s.). The stainless steel grid plate makes the corona charge uniform and controls the amount of negative charge on the drum surface by applying the negative grid bias voltage. The charge power pack [A] gives a constant corona current to the corona wires (1100 µA) and bias voltage to the grid plate is automatically controlled to maintain proper image density according to the change of the OPC drum potential due to dirty grid plate and charge corona casing.
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DRUM UNIT
2.3.2 Air Flow Around the Drum
[A]
Detailed Descriptions
[C] [B]
A176D520.wmf
The exhaust fan [A] located above the fusing unit provides an air flow to the charge corona unit to prevent uneven built-up of negative ions that can cause an uneven charge of the drum surface as shown. An ozone filter [B] absorbs the ozone (O3) around the drum. The exhaust fan rotates slowly during stand-by and rotates quickly during copying to keep the temperature inside the machine constant. 70 CPM machine has another fan (drum cooling fan), which is located at the right rear side of machine (front view). The drum cooling fan cools the drum unit to remove the heat from the duplex tray. To prevent foreign matters from entering the copier inside, a dust protection filter is installed in the entrance [C] of the duct.
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DRUM UNIT
15 July 1996
2.3.3 Charge Wire Cleaning Mechanism
[A] [C] [A]
[C]
[B]
A176D521.wmf
The flow of air around the charge corona wire may deposit toner particles on the corona wires. These particles may interfere with charging and cause low density bands on copies. The wire cleaner pads [A] automatically clean the wires to prevent such a problem. The wire cleaner is driven by a dc motor [B]. Normally the wire cleaner [C] is located at the front end position (home position). After 5000 or more copies are made and fusing temperature is less than 100°C after the main switch is turned on, the wire cleaner motor turns on to bring the wire cleaner to the rear end and then back to the home position. When the wire cleaner moves from the rear to the home position (black arrow in the illustration), the wire cleaner pads clean the wires. There are no home position and return position sensors. The CPU monitors the input voltage (5 V). When the wire cleaner reaches the end, it is stopped and the motor is locked. At this time, input voltage slightly decreases (to about 4 V) and the CPU judges to rotate the motor in reverse.
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DRUM UNIT
2.4 ERASE
2.4.1 Overview
EL LE
SE
ES LO LC
A176D522.wmf
LE: Lead edge erase margin SE: Side erase margin Lo: Original width Lc: Charged width of drum EL: Lead edge erase Es: Side erase
3.5 ± 2.5 mm total of both sides 3 mm or less
The erase lamp unit consists of a line of 123 LEDs extending across the full width of the drum, the width of each being about 2.5 mm. In editing mode, the appropriate LED's turn on according to the customer's designation.
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Detailed Descriptions
DRUM UNIT
15 July 1996
2.4.2 Lead Edge and Trail Edge Erase The entire line of LEDs turns on when the main motor turns on. They stay on until the erase margin slightly overlaps the lead edge of the original image on the drum (lead edge erase margin). It prevents the shadow of the original lead edge from appearing on the copy paper. This lead erase margin is also necessary for the lead edge of the copy paper to separate from the hot roller. The width of the lead edge erase margin can be adjusted by SP mode ( SP Adjustment - PAGE 3). When the scanner reaches the return position, the charge corona, the grid bias, and the exposure lamp turn off. However, the charged area on the drum surface is a little longer than the actual original length in order to have the entire latent image of the original. The entire line of LEDs turn on when the trail 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 drum cleaning load. The LEDs stay on to erase the lead edge of the latent image in the next copy cycle. After the final copy, the erase lamps turn off at the same time as the main motor. 2.4.3 Side Erase Based on the combination of copy paper size and the reproduction ratio data, the LEDs turn on in blocks. This prevents the shadow of the original side edge and unexposed front and rear sides of the drum surface in reduction mode from being developed. This reduces toner consumption and drum cleaning load. In the DJF mode, the horizontal original standard position on the exposure glass is 5 mm away from the rear scale. In the RDH mode, the horizontal center of the original is aligned with the center of the exposure glass. On the other hand, the horizontal original standard position on the exposure glass in the platen cover mode is the rear scale edge. To erase the shadow made by the edge of the rear scale in platen cover mode, one more LED at the front side turns on. This is in addition to the LED's on in DJF and RDH modes.
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DRUM UNIT
2.5 CLEANING
2.5.1 Overview [A]
[C]
[B] [D]
A176D523.wmf
4 mm
A176D524.wmf
This copier uses the counter blade system for drum cleaning. The blade [A] is angled against drum rotation. This counter blade system has the following advantages:
· ·
Less wearing of the cleaning blade edge. High cleaning efficiency.
Due to the high efficiency of this cleaning system, the pre-cleaning corona and cleaning bias are not used for this copier. The cleaning brush [B] is used to support the cleaning blade. The brush collects toner from the drum surface and scraped by the cleaning blade. Toner on the cleaning brush is scraped off by the mylar [C] and falls to the toner collection coil [D]. Toner is transported to the toner collection bottle by the toner collection coil. To remove the accumulated toner at the edge of the cleaning blade, the drum turns in reverse for about 4 mm at the end of every copy job. The accumulated toner is removed by the cleaning brush by this action.
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Detailed Descriptions
DRUM UNIT
15 July 1996
2.5.2 Drive Mechanism [C] [A] [E]
[B]
[D]
A176D525.wmf
The drive force from the main motor is transmitted to the cleaning unit drive gear via the timing belt [A] and the cleaning unit coupling [B]. The cleaning unit drive gear [C] then transmits the force to the front side through the cleaning brush [D]. The force at the front side is used for the toner collection coil gear [E].
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DRUM UNIT
2.5.3 Cleaning Blade Pressure Mechanism and Side-to-Side Movement [C]
[A]
[D]
[B]
A176D526.wmf
The spring [A] always pushes the cleaning blade against the OPC drum. The cleaning blade pressure can be manually released by pushing up the release lever [B]. To prevent cleaning blade deformation during the transportation, the release lever is locked in the pressure release (upper) position. The pin [C] at the rear end of the cleaning blade holder touches the cam gear [D] which gives a side-to-side movement to the blade. This movement helps to disperse accumulated toner to prevent early blade edge deterioration.
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Detailed Descriptions
DRUM UNIT
15 July 1996
2.5.4 Toner Collection Mechanism
[E]
[D]
[B] [G] [F] [A] [C]
A176D527.wmf
Toner collected by the cleaning unit is transported to the toner collection bottle [A] through the toner collection tubes. Three helical coils are used for toner transport. One coil [B] is driven by the main motor via drive belts and the other coil [C] is driven by an independent toner collection drive motor [D]. The actuator disk [E] on the toner collection drive motor monitors the proper rotation of the toner collection coil [C] to prevent the coil from being damaged by toner clogged in the collection tube. The main PCB monitors the sensor output and increases the motor speed if the sensor monitors that the toner collection motor rotates at a speed lower than normal. Also, the CPU will display an SC 342 if no signal changes (ON OFF) are detected for more than 2.55 seconds while the toner collection motor is turning. When the toner collection bottle [A] become full, the toner pressure in the bottle increases and presses the gear [F] against the toner overflow switch [G]. After the toner overflow switch is activated, the finishing of the copy job, or up to 100 continuous copies, is allowed, then copying is prohibited and the service call "full toner collection bottle" indication is displayed on the LCD. This condition can be cleared by de-actuating the toner overflow switch while de-actuating then actuating the toner collection bottle switch ([C] in next page).
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DRUM UNIT
[B]
[A]
A176D528.wmf
[C]
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2.5.5 Pick-off mechanism The pick-off pawls are always in contact with the drum surface with weak spring pressure. They move side to side during the copy cycle. This movement is made via a shaft [A] and an eccentric cam [B]. 2.5.6 Toner Collection Bottle Set Detection The toner collection bottle set switch [C] prohibits machine operation by indicating SC343 while the toner collection bottle is not set.
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Detailed Descriptions
DRUM UNIT
15 July 1996
2.6 QUENCHING
[A]
A176D530.wmf
In preparation for the next copy cycle, light from the quenching lamp (QL) [A] neutralizes any charge remaining on the drum. The quenching lamp consists of a line of 16 LEDs extending across the full width of the drum. Yellow colored LEDs are used for QL to reduce ultra violet light which would cause light fatigue on the OPC drum.
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OPTICS
3. OPTICS
3.1 OVERVIEW
[A]
Detailed Descriptions
[C] [E] [B] [D]
A176D532.wmf
The optics unit reflects an image of the original on the exposure glass onto the OPC drum. This forms a latent electrical image of the original. On this model a halogen lamp (85 V 200 W: A175 copier, 225 W: others) is used for the exposure lamp [A]. Lamp surface is frosted to ensure even exposure. Six mirrors are used to make the optics unit smaller and obtain the wide reproduction ratio range (50 ~ 200%). The lens [B] is driven by two stepping motors for (1) vertical direction (parallel to the paper feed direction) and (2) horizontal direction movements. To correct focal length change in reduction and enlargement modes, the third scanner unit [C] (4th and 5th mirrors) position is changed by a stepping motor. The toner shielding filter [D] is green (a green filter partly absorbs red light) to improve red original duplication. The optic anti-condensation heater [E] (located on the optic base plate) turns on while main switch is turned off to prevent the moisture from forming on the optics.
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OPTICS
15 July 1996
3.2 SCANNER DRIVE
[C] [A] [B]
[D]
[E]
A176D533.wmf
A dc servo motor is used as the scanner drive motor [A]. Scanner drive speed is 330 mm/s (A175 coper) or 430 mm/s (others). during scanning, and 1,950 mm/s (50/51, 60 CPM versions) or 2,670 mm/s (70 CPM version) when the scanner goes back. The scanner drive motor drives the first [B] and second scanners [C] using two scanner drive wires via the timing belt [D] and the scanner drive shaft [E]. The second scanner speed is half of the first scanner speed. The scanner drive wire is not directly wound around the pulley on the scanner drive motor.
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OPTICS
3.3 VERTICAL LENS DRIVE
[B] [A]
Enlarge
HP (100%)
Reduce (Enlarge HP) (Reduce HP) (Enlarge Enlarge) (Reduce Reduce) (Enlarge Reduce)
A176D534.wmf
(Reduce Enlarge)
30
30 30
30
steps
A176D535.wmf
The lens vertical drive motor [A] changes the lens vertical position in accordance with the selected reproduction ratio. A stepping motor (approx. 0.095 mm/step) is used to drive the lens through the lens drive belt. The maximum lens vertical shift distance is 290 mm (from the position at 50% to the position at 200%). The lens vertical home position sensor [B] detects the lens vertical position for full size mode. The optic control PCB keeps track of the lens position based on the number of pulses sent to the lens vertical drive motor.
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Detailed Descriptions
OPTICS
15 July 1996
3.4 HORIZONTAL LENS DRIVE
[A]
A176D536.wmf
40 steps Enlarge 40 HP Reduce 40
A176D537.wmf
The original horizontal position on the exposure glass varies depending on the mode (such as platen, DJF and RDH modes) for easy original handling. However, the center is the standard position for paper feed. Therefore, the lens horizontal position has to be changed according to paper size, reproduction ratio, original feed modes and the edit modes (centering, margin adjust, etc.). A stepping motor (approx. 0.07 mm/step) is used to drive the lens through the lens drive belt. The lens horizontal home position sensor [A] is used to detect the lens horizontal position for A4/LT sideways, in full size and platen mode. The other positions are determined by counting the number of motor drive pulses. Since this model has a horizontal lens drive mechanism, side-to-side registration adjustment for each feed station can be done easily by using SP mode ( SP Adjustment - PAGE 4).
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15 July 1996
OPTICS
3.5 HORIZONTAL LENS POSITIONING
3.5.1 For Original Position
Platen DJF Copy Paper RDH (Center) Horizontal Lens Position
[C]
[A]
Detailed Descriptions
[B]
A176D538.wmf A176D539.wmf
There are three standard original positions for the platen, DJF and RDH modes. In platen mode, the original is aligned with both the rear [A] and the left [B] original scales (rear left corner [C] is the standard position). In RDH mode, the original position is the center of the left scale [B]. In DJF mode, the original position is 5 mm to front of the platen mode original position to maintain the original transport path (5 mm from the rear scale). The above figure shows the lens horizontal positions for each original mode when identical size paper is used. 3.5.2 For Paper Size
Original Rear Edge
Copy Paper
Lens Position
Horizontal
A176D540.wmf
To keep high paper feed performance, the center is assigned as the paper feed standard position. Therefore, the lens horizontal position is changed according to the paper size. The figure shows the lens horizontal position for each paper size in full size mode.
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OPTICS
15 July 1996
3.5.3 For Reproduction Ratio Original Rear Edge
Original 200% 100% 50% Copy Paper
50% 100% 200% 3rd Scanner Position
A176D541.wmf
When the reproduction ratio is changed, the vertical position of the lens is changed. At the same time, the total focal length has to be changed to adjust the image focusing. For this focal length change, the horizontal position of the 3rd scanner is also adjusted. The maximum 3rd mirror shift distance is 50 mm (from the position at 100% to the position at 50, 200%). The figure shows the lens horizontal position for 50, 100 and 200%.
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15 July 1996
OPTICS
3.6 3RD SCANNER DRIVE
[B] [A]
A176D542.wmf
(Initialize)
(Reduce/Enlarge HP)
(Reduce/Enlarge Reduce/Enlarge) (Reduce/Enlarge Reduce/Enlarge) (Reduce/Enlarge Enlarge/Reduce)
40 steps
40 steps
A176D543.wmf
To compensate the focus for reproduction and lens position changes, the 3rd scanner (4th and 5th mirrors) position is changed. A stepping motor [A] (approx. 0.095 mm/step) is used for the 3rd scanner drive. The 3rd scanner home position sensor [B] is used to detect the unit position for full size mode. The optic control PCB keeps track of the unit position based on the number of motor drive pu