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SECTION 1 OVERALL MACHINE INFORMATION
23 April 1993
SPECIFICATIONS
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" (1.5K 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 Enlargement 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:
Full Size Reduction
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Overall Information
1. SPECIFICATIONS
SPECIFICATIONS
23 April 1993
Power Source:
115V, 60Hz, more than 20A (for N.A) 220 ~ 240V, 50Hz/60Hz, more than 10A (for EU and AA) A095 and A096 copiers
Copier only Warm-up Stand-by Copying Maximum 0.9 kVA 0.25 kVA 1.2 kVA 1.45 kVA Full system* 0.9 kVA 0.25 kVA 1.3 kVA 1.5 kVA
Power Consumption:
*Full System:
·
Mainframe with dual job feeder, compact sorter stapler and 3,500-sheet large capacity tray 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
Copier only 55 dB (A) Full system* 61 dB (A)
·
·
Noise Emission: sound pressure level: The measurements are Copying made according to ISO7779 Full System:
·
Mainframe with dual job feeder, compact sorter stapler and 3,500-sheet large capacity tray 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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23 April 1993
SPECIFICATIONS
Weight:
Copier only: (Without the optional platen cover = Approximately 2 kg) A095 copier: Approximately 151 kg A096 copier: Approximately 163 kg From 50% to 200% in 1% steps
Zoom: Copying Speed:
A4/LT (sideways) A095 copier A096 copier 45 55
A3/DLT 23 28
B4/LG 27 35
Warm-up Time: First Copy Time: Copy Number Input: Manual Image Density Selection: Automatic Reset: Copy Paper Capacity:
Less than 5 minutes (20°C) 3.1 seconds (A4/81/2" x 11" sideways from the 1st feed station) 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.
· · · ·
By-pass feed table: approximately 50 sheets Paper tray: approximately 550 sheets Tandem tray: approximately 500 sheets Large capacity tray: approximately 1500 sheets
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Overall Information
Dimensions:
690 x 690 x 980 (W x D x H Mainframe only) 1280 x 690 x 1020 (W x D x H Mainframe with copy tray, platen cover)
SPECIFICATIONS
23 April 1993
Toner Replenishment: Optional Equipment:
1,100 g/cartridge
· · · · · · · ·
Platen cover Dual job feeder Recirculating document handler 20 bin sorter stapler (Floor type) 20 bin compact sorter stapler Finisher 3500-sheet Large capacity tray Receiving Tray
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23 April 1993
MACHINE CONFIGURATION
2.1 COPIER OVERVIEW
There are two types of mainframe. A095 copier Three 550-sheet paper trays Optional 3,500-sheet large capacity tray
550 550 550
(3,500)
A096 copier 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 1,500 (3,500)
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Overall Information
2. MACHINE CONFIGURATION
MACHINE CONFIGURATION
23 April 1993
2.2 SYSTEM OVERVIEW
System A (The mainframe (A095) with dual job feeder and compact sorter stapler) Dual job feeder (A376)
Compact sorter stapler (A374) 3,500-sheets large capacity tray (A380)
System B (Mainframe type (A095/A096) with dual job feeder and floor type sorter stapler. The mainframe in the illustration below is the A096.) Dual job feeder (A376)
Floor type sorter stapler (A377)
3,500-sheets large capacity tray (A380)
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23 April 1993
MACHINE CONFIGURATION
(The mainframe (A096) with recirculating document handler and finisher) Recirculating document handler (A378)
Finisher (A379)
3,500-sheets large capacity tray (A380)
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Overall Information
System C
COPY PROCESS AROUND THE DRUM
23 April 1993
3. COPY PROCESS AROUND THE DRUM
11 2 1 3 4 5 6
10
9
7 8 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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23 April 1993
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.
1-9
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
23 April 1993
4. MECHANICAL COMPONENT LAYOUT
3 4 5 6 7 8 9 10 11 12
2 13 1 39 38 37 14 15 16 17 18 19 36 20 21 22 23 24 25 26 27
35
28
34
33
32
31
30
29
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23 April 1993
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 (A096 copier) 550-sheet Tray (A095 copier) 26. Universal Tray 27. 1500-sheet LCT (A096 copier) 550-sheet Tray (A095 copier) 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
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Overall Information
DRIVE LAYOUT
23 April 1993
5. DRIVE LAYOUT
9
10 11 2 1
3 4 5 6
8 7
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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23 April 1993
PAPER PATH
6.1 STANDARD COPYING
[F] [D]
[C] [B] [E] [A]
[A]
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
23 April 1993
6.2 MULTIPLE 2-SIDED COPYING
a. Front Side [A] [D] [C]
[B]
b. Rear Side
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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23 April 1993
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 M 1 M 2 M 3 M 4 M 5 M 6 M 7 M 8 M 9 Scanner Drive Exhaust Fan Main Development Drive By-pass Feed 3rd Scanner Drive Toner Bottle Drive 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. 42 43 44 45 46 47 48 49 50 Name Function Index No.
Charge Wire Cleaner Drives the main charge wire Drive cleaner to clean the charge wire. Jogger Drives the jogger fences to square the paper stack in the duplex tray (dc stepper). 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.
M10 M11 M12 M13 M14 M15 M16 M17
Lens Horizontal Drive Shifts the lens horizontal position. Lens Vertical Drive Optic Cooling Fan Fusing/Duplex Drive Paper Feed 1st Lift 2nd Lift Toner Collection
51 52 53 54 90 91 92 93
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Overall Information
7. ELECTRICAL COMPONENT DESCRIPTION
ELECTRICAL COMPONENT DESCRIPTION
23 April 1993
Symbol M18 M19
Name 3rd Lift (A095 copier only) Side Fence Drive (A096 copier only) Rear Fence Drive (A096 copier only) LCT Motor (A096 copier only)
Function 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. Lifts and lowers the LCT bottom plate to bring paper to the feed position and allow loading of the paper.
Index No. 94 95
M20
96
M21
127
Magnetic Clutches MC1 Toner Supply 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. 57
MC2 MC3 MC4
Registration By-pass Feed Duplex Transport
58 60 64
MC5 MC6 MC7 MC8
Duplex Feed 1st Feed 2nd Feed 3rd Feed
65 99 101 104
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23 April 1993
ELECTRICAL COMPONENT DESCRIPTION
Switches SW1 SW2 By-pass Table Front Door Safety 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. Determines what size paper is in the 2nd (universal) paper tray. Detects when the toner collection bottle is full. Detects if the toner collection bottle is set or not. Detects if the front door is open or not. Detects if the 3rd tray is set or not. Provides power to the copier Lowers the LCT bottom plate. 25 29
SW3 SW4 SW5 SW6 SW7 SW8 SW9 SW10
1st Tray Set (A095 copier only) 2nd Paper Size Toner Overflow Toner Collection Bottle Set Lower Front Door Safety 3rd Tray Set (A095 copier only) Main Tray Down (A096 copier only)
66 67 75 77 83 84 122 126
Solenoids SOL 1 Junction Gate 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. Controls the up-down movement of the transfer belt unit. 55
SOL 2 SOL 3
Duplex Positioning By-pass Pick-up
56 59
SOL 4
Guide Plate
61
SOL 5
Transfer Belt Positioning
62
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Overall Information
Symbol
Name
Function
Index No.
ELECTRICAL COMPONENT DESCRIPTION
23 April 1993
Symbol SOL 6
Name Pressure Arm
Function 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.
Index No. 63
SOL 7
Tandem Lock
97
SOL 8
1st Pick-up
98
SOL 9
1st Separation Roller Controls the up-down movement of the separation roller in the 1st feed station. 2nd Pick-up Controls the up-down movement of the pick-up roller in the 2nd feed station.
100
SOL10
102
SOL11
2nd Separation Roller Controls the up-down movement of the separation roller in the 2nd feed station. 3rd Pick-up Controls the up-down movement of the pick-up roller in the 3rd feed station.
103
SOL12
105
SOL13
3rd Separation Roller Controls the up-down movement of the separation roller in the 3rd feed station.
106
Sensors S 1 Scanner HP 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. 1
S 2
Platen Cover Position1
2
S 3
Platen Cover Position2
3
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23 April 1993
ELECTRICAL COMPONENT DESCRIPTION
S 4 S 5 S 6 S 7 S 8
Lens Vertical HP Lens Horizontal HP 3rd Scanner HP By-Pass Paper End Guide Plate Position
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. Detects the leading edge of the paper to determine the duplex feed clutch off timing. 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. Detects misfeeds. Detects misfeeds. Senses the background density of the original. Detects original length. Detects original length. Detects original width.
4 5 6 7 8
S 9
Jogger HP
9
S10
Vertical Transport
10
S11
Duplex Exit
11
S12
Duplex Entrance Sensor Duplex Paper End Duplex Transport
12
S13 S14
13 14
S15 S16 S17 S18 S19 S20 S21
Exit Fusing Exit Paper Guide Auto Image Density Original Length1 Original Length2 Original Width
15 16 17 20 21 22 23
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Overall Information
Symbol
Name
Function
Index No.
ELECTRICAL COMPONENT DESCRIPTION
23 April 1993
Symbol S22 S23 S24 S25 S26 S27 S28 S29 S30 S31
Name By-Pass Paper Size Toner Density Registration Toner End Auto-Response Drum Potential Image Density 1st Paper End 1st Paper Near End 1st Paper Feed
Function 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.
Index No. 26 27 28 30 34 39 41 68 69 70
S32 S33 S34 S35 S36 S37 S38 S39
2nd Paper Near End 1st Lift 2nd Paper End Toner Collection Motor 2nd Lift 3rd Lift 3rd Paper Near End (A095 copier only) 3rd Paper End
71 72 73 74 76 78 79 80
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23 April 1993
ELECTRICAL COMPONENT DESCRIPTION
S40
3rd Paper Feed
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. Detects the paper near end condition. Detects when the tray is completely lowered to stop the LCT motor. Informs the CPU when the paper is set on the LCT bottom tray.
81
S41
2nd Paper Feed
82
S42
Base Plate Down (A096 copier only) Side Fence Positioning (A096 copier only) Rear Fence Return (A096 copier only) Rear Fence HP (A096 copier only) Left Tandem Paper End (A096 copier only) LCT Near End (A096 copier only) Tray Down (A096 copier only) Tray Paper Set (A096 copier only)
85
S43
86
S44
87
S45
88
S46
89
S47 S48
123 124
S49
125
PCBs PCB 1 AC Drive PCB 2 Main PCB 3 Optic Control Provides AC power to the exposure lamp and fusing lamp. Controls all machine functions. Controls all optics components. 108 109 110 111
PCB 4 High Voltage Control Controls the output of both power packs and development bias.
1-21
Overall Information
Symbol
Name
Function
Index No.
ELECTRICAL COMPONENT DESCRIPTION
23 April 1993
Symbol
Name
Function Controls all components in the paper bank. Provides DC power. Controls the guidance display. Controls the LED matrix, and monitors the key matrix.
Index No. 112 113 120 121
PCB 5 Paper Feed Control PCB 6 DC Power Supply Unit PCB 7 Guidance PCB 8 Operation Panel
Lamps L1 L2 L3 Exposure Fusing Quenching 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
L4 L5
Erase Pre-transfer
38 40
Power Packs PP1 Transfer 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
PP2
Charge
119
Others TS1 TF1 TH1 Optics Thermoswitch Opens the exposure lamp circuit if the optics unit overheats. Fusing Thermofuse Fusing Thermistor Opens the fusing lamp circuit if the fusing unit overheats. Senses the temperature of the hot roller.
1-22
19 33 24
23 April 1993
ELECTRICAL COMPONENT DESCRIPTION
TH2 TH3
Optics Thermistor Drum Thermistor (Located on the ID Sensor Ass'y) Transfer Anti-Condensation Optics Anti-Condensation Main Power Relay Total Counter Noise Filter Circuit Breaker
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. Turns on when the main switch is off to prevent moisture from forming on the optics. Controls main power. 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.
36 41
H1
31
H2
35
RA1 CO1 NF1 CB1
107 114 115 116
LA1
Lightening Arrestor
118
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Overall Information
Symbol
Name
Function
Index No.
SECTION 2 DETAILED SECTION DESCRIPTIONS
23 April 1993
PROCESS CONTROL
1. PROCESS CONTROL
1.1 OVERVIEW
Original Scale VL Pattern
ADS Pattern VD Pattern
Latent Image Control
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 Temperature Sensor Paper TD Sensor
Image Density Control ID Sensor (Fuzzy Control) Toner Supply Control
Main PCB
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
Image Density Control (Fuzzy Control)
PROCESS CONTROL
23 April 1993
1.1.1 Latent Image Control
QL Charge Exposure Black White
Erase Potential Sensor
Vo
VD VL
VR
Drum
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 wire 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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23 April 1993
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
2-3
PROCESS CONTROL
23 April 1993
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 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 (Page 2-12) for details.
z: See Optics section (Page 2-39) for details.
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23 April 1993
PROCESS CONTROL
1.3 LATENT IMAGE CONTROL
1.3.1 Drum Potential Sensor Calibration
Case Sensor Output Amp.
[A]
Drum
RA601 -100 V RA602 -800 V
[B]
Main PCB 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
PROCESS CONTROL
23 April 1993
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] [V] Vo VD New Drum Used Drum
Drum Potential
VL
Dark
Original Density
VR Light
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 0V. Actually, there is some residual voltage even on the new drum.
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23 April 1993
PROCESS CONTROL
1.3.5 VD Correction
[-V]
Exposure Glass Drum Potential 770
VD VR VD Compensated
Detailed Descriptions
VD Pattern
After many copies New Drum VR Dark Original Density Light
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.
2-7
PROCESS CONTROL
23 April 1993
1.3.6 VL Correction
[-V]
Exposure Glass VL Pattern Drum Potential
VD Only VD Compensated VR VL 770 VR 140 VR Original Density Light VD and VL Compensated New Drum
Dark
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 first scanner moves under the VL pattern (White) stuck underneath the original scale. The pattern 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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23 April 1993
PROCESS CONTROL
1.3.7 VR Correction
[-V]
VD VD and VL Compensated VR VL Development Bias (VBB)
Detailed Descriptions
Drum Potential
770
VR 140
New Drum
VR Light
Dark
Original Density
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
23 April 1993
1.3.8 Initial Setting Sequence The following graph shows the sequence of events during process control data initial setting.
Scanner forward Motor reverse
for the purpose of ADS sensor correction
Exposure Lamp V800 VD New VD
V100 Potential Sensor Output VR 1. Potential sensor calibration
VL New VR
New VL
2. VR', VD', VL' potential detection Latent Image Control
3. VD, VL correction
4. ID sensor pattern potential detection
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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23 April 1993
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 Condition Incomplete drum potential sensor calibration Abnormal VD detection Abnormal VL detection
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
23 April 1993
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.
A C B 4 Sensor Output 3 (V) VREF 2 1
5
VIN
Main PCB VOUT AGC VD (12 V) GND
TD Sensor
VOUT = VIN x Gain 256 Gain = 12 x New Developer 256
0 1 2 3 4
Sensor Output
Toner Weight %
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 ( 1 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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23 April 1993
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
5
4 Sensor Output 3 (V) 2 VTD VREF
1
0 1 2 3 4 5 Toner Weight %
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PROCESS CONTROL
23 April 1993
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' Previous Copy Last Copy (VTD' = VTD of the previous copy cycle) VTD Next Copy
VREF
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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23 April 1993
PROCESS CONTROL
1.4.2 Image Density Sensor Detection [C] [B]
[A]
Drum
LED ON LED ON
bias
VSG
4V
VSP
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
1 2 3 4 5 6 7 8 9
VSP Detection
10 11 12 13 2nd Series of Copies (5 copies) 14 15
VSP Detection
29 30 31
1st Series of Copies (8 copies)
VSG Detection
VSG Detection
VSG Detection
3rd Series of Copies (17 copies)
VSG Detection
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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Detailed Descriptions
PROCESS CONTROL
23 April 1993
700 V
x
x Potential
Sensor Detection
VP
VP
y z
300 VIDB = VP +300 (V)
y ID Sensor
Bias Level
4.0 V
z ID Sensor Output
VSP
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 1.6 V or V100 falls under 0.1 V or whenever V800 rises over 5.0 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 V) Abnormal VSP/VSG Detection (VSP/VSG < 0.25 V) Incomplete Drum Potential Sensor Calibration
Detailed Descriptions
2-17
DRUM UNIT
23 April 1993
2. DRUM UNIT
2.1 OVERVIEW
12 13 14 15 16 1 2 3 4
11 10 9 7. 8 6 5
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
23 April 1993
2.3 DRUM CHARGE
2.3.1 Overview [A]
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/sec.). 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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23 April 1993
DRUM UNIT
2.3.2 Air Flow Around the Drum
[B]
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.
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Detailed Descriptions
[A]
DRUM UNIT
23 April 1993
2.3.3 Charge Wire Cleaning Mechanism [A] [C] [A]
[C]
[B]
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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23 April 1993
DRUM UNIT
2.4 ERASE
2.4.1 Overview
EL LE
SE
ES
LO LC
LE: SE: Lo: Lc: EL: Es:
Lead edge erase margin Side erase margin Original width Charged width of drum Lead edge erase 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
23 April 1993
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 ( 1 SP Adjustment mode: 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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23 April 1993
DRUM UNIT
2.5 CLEANING
2.5.1 Overview [A] [C]
Detailed Descriptions
[B] [D]
4 mm
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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DRUM UNIT
23 April 1993
2.5.2 Drive Mechanism
[C] [E] [A]
[B]
[D]
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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23 April 1993
DRUM UNIT
2.5.3 Cleaning Blade Pressure Mechanism and Side-to-Side Movement [C]
[A] [D]
[B]
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
23 April 1993
2.5.4 Toner Collection Mechanism
[B] [E] [D] [G] [F]
[C] [A] 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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23 April 1993
DRUM UNIT
[B]
[C] [A]
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
23 April 1993
2.6 QUENCHING
[A]
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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23 April 1993
OPTICS
3. OPTICS
3.1 OVERVIEW
[A]
Detailed Descriptions
[C] [B] [E] [D]
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 230 W) 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
23 April 1993
3.2
SCANNER DRIVE
[A]
[C]
[B]
[D]
[E]
A dc servo motor is used as the scanner drive motor [A]. Scanner drive speed is 330 mm/sec. during scanning, and 1950 mm/sec. 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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23 April 1993
OPTICS
3.3
VERTICAL LENS DRIVE
[B] [A]
Enlarge
HP (100%)
Reduce (Enlarge HP) (Reduce HP) (Enlarge Enlarge) (Reduce Reduce) (Enlarge Reduce)
(Reduce Enlarge) 30 30 30 30 steps
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
23 April 1993
3.4
HORIZONTAL LENS DRIVE
[A]
40 steps Enlarge 40 HP Reduce 40
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 ( 1 SP Adjustment mode: PAGE 4).
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23 April 1993
OPTICS
3.5
HORIZONTAL LENS POSITIONING
Platen 5 DJF
143.5
3.5.1 For Original Position
100%
[C]
Copy Paper
[A]
RDH (Center) Horizontal Lens Position
2.5
[B] 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
100%
Copy Paper
Lens Position
Horizontal
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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Detailed Descriptions
OPTICS
23 April 1993
3.5.3 For Reproduction Ratio Original Rear Edge
Original 200% 100% 50% Copy Paper
100% 50% 200% 3rd Scanner Position
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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23 April 1993
OPTICS
3.6
3RD SCANNER DRIVE
[B]
[A]
Detailed Descriptions
(Initialize) (Reduce/Enlarge HP) (Reduce/Enlarge Reduce/Enlarge) (Reduce/Enlarge Reduce/Enlarge) (Reduce/Enlarge Enlarge/Reduce) 40 steps 40 steps
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 pulses.
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OPTICS
23 April 1993
3.7
OPTICS CONTROL CIRCUIT
Sensors
E Encoder M Scanner Drive M Drive
Horizontal Lens Vertical Lens
Data Bus Main Control Board
Optics Control Board
Main CPU
Optics Control CPU
M Drive
Drive Fan
M 3rd Scanner M Optic Cooling
Exposure Lamp AC Drive Board Optic Thermistor
The optic control board communicates with the main board through a data bus. The optics control board monitors all the sensor signals, encoder output, thermistor output and controls all motors in the optics. At the programmed time, the main CPU sends a scanner start signal to the optics control CPU. The CPU generates a pulse-width modulation (PWM) signal. The PWM signal goes to a driver circuit, which sends drive pulses to the scanner drive motor. An encoder in the scanner drive motor generates pulse signals. A speed/direction control circuit monitors the scanner speed and the direction of the signals, and uses this data to regulate the motor speed. The home position sensor monitors the position of the scanner. When the main switch is turned on, the main CPU confirms the position of the scanner by moving the scanner out of the home position and back again. This data is sent to the optics control CPU.
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OPTICS
3.8
AUTOMATIC IMAGE DENSITY CONTROL SYSTEM (ADS)
[B]
[A]
In ADS mode the original background density is sensed by the ADS sensor [A] and the main CPU determines an appropriate development bias voltage for the original to prevent dirty backgrounds from appearing on copies. 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 direct the reflected light from the original to the ADS sensor. The ADS sensor standard voltage is adjusted to 2.7 V when process control data initial setting is performed. The exposure lamp turns on with ID level 4 at the home position and the light reflected by the ADS pattern [B] (white painted) reaches the ADS sensor. The main CPU adjusts the ADS gain data automatically to make the output 2.7 V. This gain data is stored in the RAM board.
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Detailed Descriptions
OPTICS
23 April 1993
90 mm A= 20 mm 9.7 (mm) M M = 1.0 (m = 50 ~ 100) M=
A
B
[V]
m (m = 101 ~ 200) 100 8.25 B= x 100 (mm) m m: reproduction ratio (50 ~ 200)
ADS Sensor Output Peak hold
ADS Original Voltage
For the first scanning of an original in ADS mode, the CPU starts sampling of the ADS sensor output while exposing the ADS pattern at the scanner home position. Then the CPU stores the maximum ADS sensor output as a reference voltage. This means that every ADS check cycle, the first scanning for the original, the ADS reference voltage is renewed by the latest exposure light reflected by the ADS pattern. In the full size mode, the CPU samples the ADS sensor output when the scanner scans the original from 9.7 mm to 18 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 to determine the proper development bias voltage. (See development bias control section for details.) The sampling length of ADS sensor output for the original differs depending on the reproduction ratio because the scanner speed is different.
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OPTICS
3.9
MANUAL IMAGE DENSITY CONTROL
When the image density is set manually, the voltage applied to the exposure lamp changes as shown in the table below.
Lighter Dev. Bias Voltage (negative) VBB 90 VBB 60 VBB Darker
Exposure Lamp Voltage
VLAMP +4.5 VLAMP +3.0 VLAMP +0.5 VLAMP VLAMP 1.5 VLAMP 3.5 VLAMP 5.5 7 6 5 4 3 2 1
Manual ID Position VLAMP: Exposure lamp voltage at ID level 4. This value is determined at process control data initial setting. VBB: Development bias (negative) voltage at ID level 4. This value is determined at process control data initial setting.
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Detailed Descriptions
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3.10 UNEVEN LIGHT INTENSITY CORRECTION
[D]
[D]
[D]
exposure intensity original illumination distribution
Shading plate
[A]
[B]
[C]
[A]
[B]
[C]
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 compensates the light intensity when the lens horizontal position is shifted ([A] to [C]). Also three shading mylars [D] intercept any diffused reflected light from outside the light path.
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OPTICS
3.11 ORIGINAL SIZE DETECTION IN PLATEN MODE
[E] [B] [D] [C]
[A]
There are three reflective sensors (APS sensors) in the optics cavity for the original size detection. Original width Sensor [A] is used for sensing the original width and Original Length Sensor-1 [B] and Original Length Sensor-2 [C] sense the original length. Inside each APS sensor, there is an LED [D] and three photoelectric devices [E]. The light generated by the LED is broken up in three beams and each beam scans a different point of the exposure glass. If the original or platen cover is present over the scanning point, the beam is reflected and each reflected 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 cover is opened.
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Detailed Descriptions
OPTICS
23 April 1993
[A]
Original Size A4/A3 version A3 B4 -- F4 A4L B5L A5L B6L A6L A4S B5S A5S A6S LT/DLT version 11 x 7 10 x 14 81/2 x 14 8 x 13 81/2 x 11 -- 51/2 x 81/2 -- -- 11 x 81/2 -- 81/2 x 51/2 --
Length Sensor 1 Length Sensor 2 1 O X X X X X X X X X X X X 2 O O O X X X X X X X X X X 3 O O O O X X X X X X X X X 4 O O O O O O X X O X X X 5 O O O O O O O O X O O X X 6 O O O O O O O O O O O X
Width Sensor 7 O O O O O O X X X O O O X 8 O O O O O X X X X O O X X 9 O O X X X X X X X O O X X
NOTE: L: Lengthwise S: Sideways Sensors #4 and #6 are not used for LT/DLT version machines. The check is done when the platen position sensor [A] turns on. This is when the platen is positioned about 15 cm above the exposure glass. At this time, only the sensor(s) located underneath the original receive the reflected light and are on. Other sensor(s) are off. Through the on/off data of the nine (seven for LT/DLT version machine) sensors, the main CPU can recognize the original size. In case the copy is made with the platen open, the main CPU decides the original size only through the data when the Print key is pressed. This original size detection method eliminates the necessity for a pre-scan and increases the machine's productivity.