Ricoh FT8982, FT680 Service Manual FT8982

IMPORTANT SAFETY NOTICES

PREVENTION OF PHYSICAL INJ URY

1. While the machine warms up, it will suddenly start turning to perform the process control data initializa tio n. Keep hands away from any mechanical and electrical components during this perio d.

2. Before disassembling or assembling parts of the copier and periph erals, make sure that the copie r and the secon d sorter power cord is unplugged.

3. The wall outlet should be near the copie r and easily acce ssible .

4. Note that some comp onen ts of the copier, the paper tray un it, and the 2nd sorter are supplied with electrical volta ge even if the main switch is turned off.

5. If any adjustment or operation check has to be made with exte rior cove rs off or open while the main switch is turned on, keep hands away from electrified or mechanically driven components.

6. The inside and the meta l pa rt s of the fusing unit become ext reme ly hot while the copier is operating. Be careful to avoid touch ing tho se components with your bare hands.

HEALTH SAFETY CONDITIONS

1. Never operate the copier without the ozone filte rs in sta lled.

2. Always replace the ozo ne filte rs wit h th e specified ones at the specified intervals.

3. Toner and developer a re non-toxic, but if you get either of them in your eyes by accident, it may cause tempo rary eye discomf ort. Try to remove with eye drops or flush with water as f irst aid . If unsu ccessful, get medical attention .

OBSERVANCE OF ELECTRICAL SAFETY S TANDARDS

1. The copier and its peripherals must be inst alle d and main ta ine d by a customer service represent at ive who has completed the training course on those models.

2. The RAM board on the main contro l board ha s a lithium battery which can explode if replaced incorrectly. Replace the battery only with an ide nt ical one. The manufacture r recomme nd s replacing the entire RAM board. Do not recharge or burn this battery. Used batteries must be handled in accordance with local regulations.

SAFETY AND ECOLOGICAL NOTES FOR DI S POSAL

1. Do not incinerate the ton er cartridge or the used tone r. Ton er du st may ignite suddenly when exposed to open flame.

2. Dispose of used toner, developer, and photoconductors according to local regulations.

3. Dispose of replaced part s in accord an ce with local regulations.

4. When keeping used lithium batteries in order to disp ose of them later, do not put more than 100 batteries per sealed box. Storing larger numb ers or not sealing them apart may lead to chemica l re act ions and heat build-up.

SECTION 1

OVERALL MACHINE

INFORMATION

31 July 1995 SPECIFICATIONS

1. SPECIFICATIONS

Main Copier

Copier

Configuration: Console Copy Process: Dry Electrostatic Transfer S yste m Originals: Sheet/Book Original Size: Maximum:

11" x 17", A3 420 x 700 mm (in moving-original scan mode, Europe version only)

Copy Paper Size: Maximum:

1st and 2nd tray 11" x 17", A3 3rd tray 81/2" x 14", B4 By-pass table in moving-original scan mode (Europe version only) 420 x 700 mm

Minimum:

Tray 51/2" x 81/2", A5 By-pass table in moving-original scan mode (Europe version only) A5

Copy Paper Weight: Standard Copying: 14 ~ 42 lb, 52 ~ 157 g/m

Duplex Copying: 17 ~ 28 lb, 64 ~ 105 g/m Tab Sheets: 90 lb index, 160 g/m

Warm Up Time: Within 8.0 minutes (room temp. 68°F, 20°C) First Copy Time: 3.8 seconds (81/2" x 11", A4, copier only)

6.9 seconds (81/2" x 11", A4, with sorter stapler)

Copying Speed: 80 copies/minute (81/2" x 11")

82 copies/ minute (A4 )

Optional Equipment: 20 Bin Sorter 1 (A591)

20 Bin Sorter 2 (A591) Large Capacity Tray (A592) Key Counter Bracket Set (A59 8 - 00) Key Counter (Procured loca lly) Key Counter Holder (Procured loca lly) Receiving Tray (spare part) Guidance ROM Kit (A603)

2 2

1-1

SPECIFICATIONS 31 July 1995

Reproduction Ratios: See the following table:

LT/DLT version A4/A3 version

200% 200%

Enlargement

Full Size 100% 100%

Reduction

155% 141% 129% 122% 121% 115%

93% 93% 77% 82% 74% 71% 65% 65% 50% 50%

Zoom: 50 ~ 200% Copy Exit Tray Capacity: 250 Sheets Toner Replenishment : Cartridge exchange (15 00 g) Paper Feed: 1st tray (500 sheets)

2nd tray (500 sheets) 3rd tray (1,700 Sheets) By-pass tray (40 sheets) (Europ ea n versio n)

Power Source: 240 V, 20 A or more (LT/DLT version)

220, 230, 240 V, 13 A or more (A4 /A 3 version)

Power Consumption:

LT/DLT version

Copier only Full system*

Warm up less than 2.10 kW less than 2.15 kW Stand-by less than 0.50 kW less than 0.55 kW

Copying less than 2.50 kW less than 2.60 kW

Maximum less than 2.60 kW less than 2.70 kW

* Full system: Copier with document feeder, large capacity tray, and a sorter stapler.

A4/A3 version (at 230 V)

Copier only Full system*

Warm up less than 2.0 kW less than 2.05 kW Stand-by less than 0.55 kW less than 0.6 kW

Copying less than 2.4 kW less than 2.5 kW

Maximum less than 2.5 kW less than 2.6 kW

* Full system: Copier with document feeder, large capacity tray, and a sorter stapler.

1-2

31 July 1995 SPECIFICATIONS

Dimensions:

LT/DLT version

Width Depth Height

Copier with document feeder and copy tray 1,375 mm

54.2"

Copier with document feeder and one sorter stapler

Copier with document feeder, large capacity tray, and one sorter stapler

Copier with document feeder, large capacity tray, and two sorter staplers

1,625 mm

64.0"

2,070 mm

81.5"

2,610 mm

102.8"

760 mm

30.0"

873 mm

34.4"

873 mm

34.4"

873 mm

34.4"

1,445 mm

56.9"

1,445 mm

56.9"

1,445 mm

56.9’

1,445 mm

56.9’

A4/A3 version

Width Depth Height

Copier with document feeder and copy tray 1,438 mm

56.7"

Copier with document feeder and one sorter stapler

Copier with document feeder, large capacity tray, and one sorter stapler

Copier with document feeder, large capacity tray, and two sorter staplers

1,688 mm

66.5"

2,070 mm

81.5"

2,610 mm

102.8"

760 mm

30.0"

873 mm

34.4"

873 mm

34.4"

873 mm

34.4"

1,445 mm

56.9"

1,445 mm

56.9"

1,445 mm

56.9"

1,445 mm

56.9"

Weight:

Copier with document feeder 367 kg

Copier with document feeder and one sorter stapler

Copier with document feeder, large capacity tray, and one sorter stapler

Copier with document feeder, large capacity tray, and two sorter staplers

LT\DLT version A4\A3 version

377 kg

809.1 lb 465 kg

1025.2 lb 506 kg

1115.6 lb 596 kg

1314. 0 lb

831.2 lb 475 kg

1047.2 lb 516 kg

1137.6 lb 616 kg

1358.1 lb

1-3

SPECIFICATIONS 31 July 1995

Noise Emission:

Sound pressure level

(The measurements are made according to ISO 7779 at the operator position.)

Copier only Full system*

Stand-by less than 42 dB (A) less than 42 dB (A)

Copying

* Full system: Copier with document feeder, large capacity tray, and a sorter stapler.

less than 63 dB (A)

(average)

less than 64 dB (A)

(average)

Sound power level (The measurements are made according to ISO 7779.)

Copier only Full system*

Stand-by less than 58 dB (A) less than 62 dB (A)

Copying less than 74 dB (A) less than 78 dB (A)

* Full system: Copier with document feeder, large capacity tray, and a sorter stapler.

Document Feeder

Original Size:

Stack feed

mode

Maximum 11" x 17", A3 11" x 17", A3 11" x 17", A3 A2

Minimum 8

1/2" x 11", A4 51/2" x 81/2", A5 81/2" x 11", A4 B5

Single feed

mode

Duplex mode

Original Weight:

Stack feed

mode

Maximum 34 lb, 128 g/m

Minimum 14 lb, 52 g/m

Single feed

42 lb, 157 g/m

11 lb, 35 g/m

mode

Duplex mode

25 lb, 93 g/m

14 lb, 52 g/m

2 2

Feed-in Unit Capacity: 50 Shee ts (80 g/m2, 20 lb) CFF Original Stack Height:Maximum: 50 mm Original Set: First sheet on top, stack face down

Moving-Original

Scan

Moving-Original

Scan

93 52

1-4

31 July 1995 SPECIFICATIONS

MEMO:

1-5

COPY PROCESSES AROUND THE DRUM 31 July 1995

2. COPY PROCESSES AROUND THE DRUM

A171V513.img

1-6

31 July 1995 COPY PROCESSES AROUND THE DRUM

1. DRUM CHARGE In the dark, the charge corona unit gives a uniform positive charge to the selenium drum. The charge remains on the surface of the drum because the photo conductive selenium has electrical resistance in the dark.

2. EXPOSURE An image of the original is reflected to the selenium drum surface via the optics assembly. 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.

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

4. DRUM POTENTIAL SENSOR The drum potential sensor detects the electric lines of force from the electric potential on the drum to compensate image processing elements.

5. DEVELOPMENT Negatively charged toner is attracted to the positively charged areas of the drum, thus developing the latent image. (The negative triboelectric charge is caused by friction between the carrier and toner particles.)

6. PRE-TRANSFER The pre-transfer corona (PTC) applies a negative dc charge and an ac charge to the drum. The dc charge increases the negative potential of the toner to improve toner transfer to paper. The ac charge decreases positive charge on the drum and makes paper separation easier. The pre-transfer lamp (PTL) also makes paper separation easier by illuminating the drum and decreasing the positive charge on the drum.

7. IMAGE TRANSFER Paper is fed to the drum surface at the proper time so as to align the copy paper and the developed image on the drum surface. Then, a strong positive charge is applied to the back side of the copy paper, providing an electrical force which causes the copy paper to be attracted to the drum’s surface. At the same time, the toner particles are pulled to the copy paper from the drum’s surface.

8. PAPER SEPARATION A strong ac corona discharge is applied to the back side of the copy paper, reducing the positive charge on the copy paper and breaking the electrical attraction between the paper and the drum. Then, the stiffness of the copy paper causes it to separate from the drum surface. The pick-off pawls help to separate paper which has low stiffness.

9. CLEANING The cleaning brush first removes remaining toner on the drum surface. Then, the cleaning blade which is angled against drum rotation (counter blade system) removes the rest of the toner. The flick roller mechanically removes the toner on the cleaning brush.

10. QUENCHING

Light from the quenching lamp electrically neutralizes the drum surface.

1-7

18192021222324

MECHANICAL COMPONENT LAYOUT 31 July 1995

3. MECHANICAL COMPONENT LAYOUT

3.1 COPIER

302928 31

121314151617

3 4

5 6

7 8 9

A171V500.wmf

1. First Mirror

2. Second Mirror

3. Third Mirror

4. Inverter Guide Plates

5. Hot Roller

6. Pressure Roller

7. Duplex Tray

8. First Tray

9. Second Tray

10. Pick-up Roller

11. Separation Roller

12. Paper Feed Roller

13. Vertical Transport Unit-Right

14. Third Tray

15. Horizontal Transport Unit

16. Pick-off Pawls 17 Transfer and Separation Corona Unit

18. Vertical Transport Unit-Left

19. Registration Rollers

20. Pre-transfer Corona Unit

21. By-pass Feed Table (Europe version only)

22. Toner Hopper

23. Development Unit

24. Drum Thermistor and Drum Potential Sensor

25. Erase Lamp

26. Fifth Mirror

27. Fourth Mirror

28. Sixth Mirror

29. Charge Corona Unit

30. Quenching Lamp

31. Cleaning Unit

32. Transport Unit

1-8

31 July 1995 MECHANICAL COMPONENT LAYOUT

3.2 ARDF

12 34 5 6 7

1. Original Tray Extension

2. Upper Exit Rollers

10. 1st Pick-up Rollers

11. 2nd Pick-up Rollers

12131415161718

A171V509.img

3. Upper Inverter Gate

4. Lower Inverter Rollers

5. Upper Inverter Rollers

6. Switch Back Gate

7. Switch Back Tray

8. Upper Relay Roller

9. Friction Tab

12. Separation Rollers

13. Lower Relay Roller

14. Pressure Rollers

15. Transport Belt

16. Lower Inverter Gate

17. Lower Exit Rollers

18. CFF Guide

1-9

ELECTRICAL COMPONENT DESCRIPTIONS 31 July 1995

4. ELECTRICAL COMPONENT DESCRIPTIONS

Refer to the electrical compon en t layo ut on the reverse side of the Point to Point (Water proof paper) index numbers.

4.1 COPIER

Name Function Index. No.

Motors

1st Tray Drive Drives the bottom plate in the 1st tray. 64 2nd Tray Drive Drives the bottom plate in the 2nd tray. 65 3rd Tray Drive Drives the bottom plate in the 3rd tray. 71 Charge Wire Cleaner Drives the charge corona wire cleaner. 79 Development Drives the development unit. 50 End Fence Drive Drives the duplex end fence. 128 Fusing Cooling Fan Cools fins of the de-curling roller. 57 Fusing Exhaust Fan Removes the heat in the de-curling unit. 63 Jogger Fence Drive Drives the duplex jogger fences. 129 LCT Drive Drives the bottom plate in the LCT. 150 Lens Horizontal Drive Shifts the lens horizontal position. 55 Lens Vertical Drive Shifts the lens vertical position. 58 Main Drives the main unit components. 77 Mirror Unit Drive Positions the mirror unit. 84 Optics Cooling 1 Removes the heat from the optics unit. 82 Optics Cooling 2 Removes the heat from the optics unit. 81 Scanner Drive Drive the 1st and 2nd scanners. 56 T & S Wire Cleaner Drives the transfer and separation wire cleaner. 75 Toner Supply Rotates the toner supply roller. 78 Vacuum Fan Removes the heat and dust in the machine. 53

Clutches

LCT Drive Transmits the main copier drive to the LCT feed

section.

Left Vertical Transport Unit Drive

Paper Feed - 1st Tray Drives the paper feed roller of the 1st tray. 67 Paper Feed - 2nd Tray Drives the paper feed roller of the 2nd tray. 66 Paper Feed - 3rd Tray Drives the paper feed roller of the 3rd tray. 76 Paper Feed - Duplex Drives the paper feed roller of the duplex unit. 130 Paper Feed - LCT Drives the paper feed roller of the LCT. 138 Right Vertical Transport

Unit Drive Registration Drives the registration roller. 72 Paper Feed - By-pass Drives the paper feed roller of the by-pass feed table. 51

PCBs

DC Drive Drives dc components. 115 DC Motor Drive Drives the dc motors. 125

Transmits the main copier drive to the left vertical transport unit and the 3rd trays.

Transmits the main copier drive to the right vertical transport unit and the 1st and 2nd trays.

1-10

31 July 1995 ELECTRICAL COMPONENT DESCRIPTIONS

Name Function Index. No.

Drum Current Detection Measures the corona current. 106 Main Controls overall machine operation. 121 Motor Control Controls the dc motors. 124 Operation Unit Controls the monitor display. 127 PTL Controls the pre-transfer lamp operation. 120 Quenching Lamp Controls the quenching lamp operation. 119 Interface Interface between the main PCB and other PCBs. 114 Vacuum Motor Controls the vacuum fan motor operation. 108

Power Packs

Charge Provides power for the charge corona wire. 103 Development Bias Provides power for the development bias. 104 PTC Provides power for the pre-transfer corona wire. 107 Separation Provides power for the separation corona wire. 105 Transfer Provides power for the transfer corona wire. 126 Power Supply Unit Provides dc power to dc components. 118

Relays

Anticondensation Heater Provides power to the anticondensation heater. 112 Drum Heater 1 Provides power to the drum heater. 113 Drum Heater 2 Provides power to the drum heater. 110 Fusing SSR Provides power to the fusing lamp. 111 Relay Unit Provides ac power to ac components. 117

Sensor

Auto Response Turns on the display from the screen saver condition. 93 By-pass Table Detects when the by-pass table is opened and

indicates the display on CRT screen. Drum Potential Detects the drum surface voltage. 100 Duplex Entrance Detects misfeeds. 137 End Fence Home

Position Exit Detects misfeeds. 10 Fusing Unit Detects misfeeds. 9 Image Density Measures the density of the image on the drum. 87 Jogger Home Position Detects when the duplex side plate is at the home

Lens Horizontal Encoder Detects the lens horizontal drive motor operation. 5 Lens Horizontal Home

Position Lens Vertical Encoder Detects the lens vertical drive motor operation. 7 Lens Vertical Home

Position Lower Limit - 1st Tray Turns off the 1st tray motor when the tray reaches the

Lower Limit - 2nd Tray Turns off the 2nd tray motor when the tray reaches

Detects when the duplex end fence is at the home

position

position.

Detects when the lens is at the horizontal home

position.

Detects when the lens is at the vertical home position.

down position.

the down position.

136

131

48A

48B

1-11

ELECTRICAL COMPONENT DESCRIPTIONS 31 July 1995

Name Function Index. No.

Lower Limit - 3rd Tray Turns off the 3rd tray motor when the tray reaches

the down position. Lower Limit - LCT Turns off the LCT motor when the tray reaches the

down position. Mirror Unit Encoder Detects the mirror drive motor operation. 37 Mirror Unit Home

Position Paper End - 1st Tray Detects the presence of paper in the 1st tray. 49A Paper End - 2nd Tray Detects the presence of paper in the 2nd tray. 49B Paper End - 3rd Tray Detects the presence of paper in the 3rd tray. 49C Paper End - By-pass

Table Paper End - Duplex Detects the presence of paper in the duplex tray. 132 Paper End - LCT Detects the presence of paper in the LCT. 141 Paper Feed - 1st Tray Turn off the 1st tray paper feed clutch. 15 Paper Feed - 2nd Tray Turn off the 2nd tray paper feed clutch. 14 Paper Feed - 3rd Tray Turns off the 3rd tray paper feed clutch. 20 Paper Feed - Duplex Turns off the duplex paper feed clutch. 133 Paper Feed - LCT Turn off the LCT paper feed clutch. 153 Paper Feed - By-pass Turn off the by-pass paper feed clutch. 36 Paper Size 1 - 1st Tray Determines what paper size is in the 1st tray. 42A Paper Size 1 - 2nd Tray Determines what paper size is in the 2nd tray. 42B Paper Size 1 - By-pass

Feed Paper Size 1 - LCT Determines what paper size is in the LCT. 142 Paper Size 2 - 1st Tray Determines what paper size is in the 1st tray. 41A Paper Size 2 - 2nd Tray Determines what paper size is in the 2nd tray. 41B Paper Size 2 - By-pass

Feed Paper Size 2 - LCT Determines what paper size is in the LCT. 143 Paper Size 3 - 1st Tray Determines what paper size is in the 1st tray. 40A Paper Size 3 - 2nd Tray Determines what paper size is in the 2nd tray. 40B Paper Size 3 - By-pass

Feed Paper Size 3 - LCT Determines what paper size is in the LCT. 144 Paper Size 4 - 1st Tray Determines what paper size is in the 1st tray. 39A Paper Size 4 - 2nd Tray Determines what paper size is in the 2nd tray. 39B Paper Size 4 - By-pass

Feed Paper Size 5 - 1st Tray Determines what paper size is in the 1st tray. 46A Paper Size 5 - 2nd Tray Determines what paper size is in the 2nd tray. 46B Paper Size 6 - 1st Tray Determines what paper size is in the 1st tray. 45A Paper Size 6 - 2nd Tray Determines what paper size is in the 2nd tray. 45B Paper Size 7 - 1st Tray Determines what paper size is in the 1st tray. 44A Paper Size 7 - 2nd Tray Determines what paper size is in the 2nd tray. 44B Paper Size 8 - 1st Tray Determines what paper size is in the 1st tray. 43A Paper Size 8 - 2nd Tray Determines what paper size is in the 2nd tray. 43B

Detects when the mirror unit is at the home position.

Detects the presence of paper in the by-pass table.

Determines what paper size is in the by-pass feed

tray. (European version only)

Determines what paper size is in the by-pass feed

tray. (European version only)

Determines what paper size is in the by-pass feed

tray. (European version only)

Determines what paper size is in the by-pass feed

tray. (European version only)

48C

146

1-12

31 July 1995 ELECTRICAL COMPONENT DESCRIPTIONS

Name Function Index. No.

Paper Volume - 1st Tray Detects the amount of paper in the 1st tray. 38A Paper Volume - 2nd Tray Detects the amount of paper in the 2nd tray. 38B Paper Volume - 3rd Tray Detects the amount of paper in the 3rd tray. 38C Paper Volume - LCT Detects the amount of paper in the LCT. 148 Registration Sensor Detects the lead edge of paper to determine the stop

timing of a feed clutch and detects misfeeds. Return Home Position Detects when the 1st scanner is at the return position. 31 Scanner Home Position Detects when the 1st scanner is at the home position. 8 Sheet Through Home

Position Toner Cartridge Detects when a toner cartridge is in the machine. 2 Toner Coil Overload Detects the toner collection coil drive gear operation. 1 Toner Near End Detects toner near end condition. 35 Transport Detects misfeeds. 18 LCT Paper Position Detects the top sheet position in the LCT tray. 140 Upper Limit - 1st Tray Sends signal to stop lifting up the 1st tray bottom

Upper Limit - 2nd Tray Sends signal to stop lifting up the 2nd tray bottom

Upper Limit - 3rd Tray Sends signal to stop lifting up the 3rd tray bottom

Upper Limit - LCT Sends signal to stop lifting up the LCT bottom plate. 151 Duplex Exit Jam detector. 16

Detects when the 1st scanner is at the 1 sheet

through home position. (European version only)

plate.

Solenoids

Cleaning Brings the cleaning blade into contact with the drum. 54 Inverter Gate Drives the inverter gate up and down. 62 Junction Gate Drives the junction gate up and down. 61 LCT Lock Locks the LCT. 139 Pick-up - 1st Tray Lifts the pick-up roller of the 1st tray. 69 Pick-up - 2nd Tray Lifts the pick-up roller of the 2nd tray. 70 Pick-up - 3rd Tray Lifts the pick-up roller of the 3rd tray. 73 Pick-up - LCT Lifts the pick-up roller of the LCT. 149 Pick-up - By-pass Lifts the pick-up roller of the by-pass feed table. 83 Pinch Roller Brings the return pinch rollers into contact with a

paper. Duplex Pressure Plate Brings the pressure plate on papers in the duplex unit. 134 Positioning Lowers the positioning roller in the duplex unit. 135 Original Scale Moves the original scale to the sheet through position

(European version only). By-pass Gate Moves the by-pass gate to the down position. 80

Switches

1st Tray Down Lowers the 1st tray bottom plate. 47A 2nd Tray Down Lowers the 2nd tray bottom plate. 47B 3rd Tray Down Lowers the 3rd tray bottom plate. 47C LCT Down Lowers the LCT bottom plate. 147

1-13

ELECTRICAL COMPONENT DESCRIPTIONS 31 July 1995

Name Function Index. No.

Anticondensation Turns on the tray heaters. 23 Error Reset Resets error condition. 11 LCT Cover Turns off components when the LCT top cover is

open. Left Door 1 Turns off the main motor when the left door is open. 25 Left Door 2 Turns off dc 24 volts lines when the left door is open. 24 Main Supplies power to the copier. 26 Right Door 1 Turns off dc 24 volts lines when the right door is open. 21 Right Door 2 Turns off the main motor when the right door is open. 17

Heaters

1st Tray Removes humidity from the paper in the 1st tray. 91 2nd Tray Removes humidity from the paper in the 2nd tray. 92 3rd Tray Removes humidity from the paper in the 3rd tray. 94 Anticondensation Prevents moisture from forming on the lens and

mirrors. Drum Warms the drum when it gets too cool. 95 Exposure Lamp Warms the exposure lamp when it gets too cool. 86 LCT Removes humidity from the paper in the LCT. 145

152

101

Lamps

Exposure Exposes the original with high intensity light. 85 Fusing Provides heat to the hot roller and keeps the roller at

the operating temperature. Pre-Transfer Removes excessive positive charge from the drum

surface to the transfer and separation process. Quenching Electrically neutralizes the drum surface prior to

charging. Eraser Discharges the drum outside the image area.

Provides lead/trail edge erase.

Thermistors

Drum Monitors the drum temperature. 99 Fusing Monitors the hot roller temperature. 88

Other Components

Total Counter Keeps a count of the number of copies made. 116 FL Stabilizer Stabilizes power to the exposure lamp. 109 Thermofuse Provides back-up overheat protection in the fusing

unit. Anticondensation

Thermoswitch

Turns off the anticondensation and drum heaters.

102

1-14

31 July 1995 ELECTRICAL COMPONENT DESCRIPTIONS

4.2 ARDF

Symbol Name Function Index. No.

Motors

M1 M2 Belt Drives the transport belt. 16

M3 Inverter Drives the inverter rollers and the exit rollers. 17 M4 Job Separation Drives the job separator. 5

Circuit Boards

PCB1 DF Main Controls overall ARDF functions. 3 PCB2

Solenoids

SOL1

SOL2 Inverter Gate Opens the inverter gate. 23 SOL3

SOL4

Feed-in Drives the pick-up rollers, separation rollers

and relay rollers.

Indicator Indicates the Insert Original indicator and the

Auto Feed indicator.

Switch Back Switches the switch back gate position to

directs the original to the switch back tray or onto the exposure glass.

Moving Original Scan Gate

Sheet-through Guide

Opens the moving original scan gate (European version only).

Moves the sheet-through guide to the sheet through position (European version only).

Sensors

S1 Entrance Cover Detects if the entrance cover is open. 4 S2 Lift Detects if the transport unit is open. 14 S3 Inverter Cover Detects if the inverter cover is open. 22

S8 S9 Inverter Jam Detects paper jams in switch back operation. 18

S10

S11

S12 Exit Detects paper jams. 21

S13

Pick-up Roller H.P.

Job Separation H.P.

Job Completion Detects that last original of the first job is fed

Original Detects if the original is set on the original

Registration Sets the feed-in motor, belt motor and inverter

Inverter Registration

Inverter Entrance Sets the inverter motor and the belt motor off,

CFF Detects if the computer form is set in the CFF

Detects if the pick-up roller is in the home position.

Detects if the job separator is in the home position.

from the original table.

table.

motor off timing. Detects original misfeed.

Sets the inverter motor and the belt motor off, reversing timing. Detects original jams.

reversing timing, inverter solenoid and switch back solenoid off timing.

guide. Counts the holes lined up on the computer form.

1-15

ELECTRICAL COMPONENT DESCRIPTIONS 31 July 1995

S14 Original Width Detects the original width. 13 S15 Timing Supplies timing pulses to the DF main board. 10

S16

Others

Oth1

Oth2

Moving Original Scan Entrance

CFF Guide Switch Detects whether the CFF guide is in the rear

Sheet Feed Clutch

Detects when the original is set on the moving original scan entrance (European version only).

end position or not (European version only). Drives the sheet feed rollers (European

version only).

1-16

31 July 1995 DRIVE LAYOUT

5. DRIVE LAYOUT

A171V510.img

A171V511.img

A171V508.img

A171V506.img

A171V507.img

1. Main Motor

2. Development Drive Motor

A171V512.img

A : Development Unit B : Cleaning Unit C : Relay Transport Unit (to LCT & By-pass Table) D : Fusing Unit E : Vertical Transport Unit-Right F : Duplex Unit G: Vertical Transport Unit-Lef t

1-17

PAPER PATH 31 July 1995

6. PAPER PATH

6.1 SINGLE SIDED COPY – COPY FACE DOWN

6.2 DUPLEX MODE (1ST SIDE)

A171V501.wmf

1-18

A171V502.wmf

31 July 1995 PAPER PATH

6.3 DUPLEX MODE (2ND SIDE)

6.4 IMAGE OVERLAY MODE (1 ST SIDE)

A171V503.wmf

1-19

A171V504.wmf

PAPER PATH 31 July 1995

6.5 IMAGE OVERLAY MODE (2ND SIDE )

A171V505.wmf

1-20

SECTION 2

DETAILED SECTION

DESCRIPTIONS

Drum Current Detection PCB

31 July 1995 PROCESS CONTROL

1. PROCESS CONTROL

1.1 OVERVIEW

The characteristics of each unit which is relat ed to the cop y ima ge reproduction are changed by various factors. To get stable images over long periods and in continuous copy run s, th ese chara cteristic changes have to be compensated. The following figure and table show how these facto rs are compensated on this copier.

Potential Sensor

Toner Supply

Development Bias

Exposure Lamp

PTC

Main PCB

Transfer Corona

Charge Corona

ID Sensor

Separation Corona

: Sensing Item : Controlled Item

A171D522.wmf

2-1

PROCESS CONTROL 31 July 1995

Section Characteristics Causes of Change Compensation Method

Drum Charge Potential Repeat Stress

Temperature Humidity

Sensitivity Repeat Stress

Temperature Humidity

Residual Voltage

Charge Corona

Exposure Lamp Intensity Repeat Stress Measure the drum potential of a part

Development Amount of

Charge Potential Dirtiness

Mirror Reflectivity Lens Clearness

Toner Charge

Repeat Stress Temperature Humidity

Temperature Humidity

Dirtiness

Repeat Stress Temperature Humidity

Measure the drum potential of a part that was not exposed (Dark Potential) with the potential sensor and adjust the charge corona output.

Measure the drum potential of a part that was exposed (Light Potential) and adjust the exposure lamp voltage.

Measure the drum potential of a part that was erased by the erase lamp (residual voltage) and adjust the development bias, light potential, and dark potential

Measure the drum potential of a part that was not exposed (dark potential) and adjust the charge corona output.

that was exposed (light potential) and adjust the exposure lamp voltage.

Measure the reflected light intensity of the ID sensor pattern and adjust the toner density in the development unit.

2-2

31 July 1995 PROCESS CONTROL

1.2 IMAGE CONTROL

1.2.1 Latent Image Control

Charge

Exposure

Black White

Erase

Potential Sensor

Drum

A171D507.wmf

The figure shows the change s of the drum potential durin g the copy process. V0: The drum potentia l just af te r charging the drum. Vd (Dark Potential): The drum potential just after exposing the black

pattern (Vd pattern)

VL (Light Potential): The drum potential just after exposing the white

pattern (VL pattern)

Vr (Residual Voltage): The drum potential just after t he expo sure of the

erase lamp.

2-3

PROCESS CONTROL 31 July 1995

Drum Potential

LightOriginal DensityDark

A171D519.wmf

The above figure shows the relatio nsh ip be twe en the drum pote nt ial and th e original density (exposing ligh t intensity). To get constant copy quality, this relationship must be maintained.

Since this relationship tends to change to the one rep resented by the dotted line by various factors, compensations are required as follows:

A decrease in dark voltage (Vd) is compensated for by increasing the charge corona output. A increase in light voltage (VL) is compensated for by increasing the exposu re lamp voltage. Since the resid ual vo lta ge (V r ) increase cannot be compen sat ed for by increasing the lamp voltage , it is compensated by increasing the development bias voltage and changing the Vd and VL standard value.

1.2.2 Image Density Control

To maintain constant copy image density, the ID sensor dete cts the toner amount of the ID sensor pattern. From this, it is understood that drum potential is stabilized with the above compe nsa tions. According to the detection results, the ton er density in the development unit is controlled so that the toner amount on the sensor pattern is constant.

The following sections explain the details of these compensations.

2-4

31 July 1995 PROCESS CONTROL

1.3 PROCESS CONTROL DATA INITIALIZATIO N

The following flow chart shows all t he st eps tha t will be performed whenever the main switch is turned on while the hot roller temperature is below 100°C. This initializes all the process control set tings.

Main SW On (Fusing Temp. < 100°C)

Drum Potential Sensor Calibration (Fusing Temp . = 160°C)

Drum Conditioning Start (Fusing Temp . = 160 ° C)

• Exposure lamp ON

Vsg Adjustment

Lamp Intensity Sensor Calibration

Charge Corona Current Adjustment

Vr Measurement

• Lens position shift

• Exposure lamp OFF

• Scanner moves to return position (Vd Pattern)

• Exposure lamp ON

Vd Correction

• Exposure lamp OFF

• Scanner returns to home position (VL Pattern)

• Exposure lamp ON

VL1 Correction

• Exposure lamp OFF

V01 Detection

• Scanner moves to re tu rn po sitio n (ADS Pat te rn)

• Exposure lamp ON

ADS Adjustment

2-5

TRIG 1 (800V)

TRIG 2 (100V)

PWM

Sensor

PROCESS CONTROL 31 July 1995

1.3.1 Drum Potential Sensor Calibration

[A]

A171D585.img

Potential Sensor

Bias P.P.

Case

Sensor

Output

Amp.

Drum

A171D512.wmf

RA2

RA1

Drum Current Detection PCB

Relay

Main PCB

A171D511.wmf

The drum potential sensor [A] is locat ed just ab ove the deve lop men t un it. The sensor has a detector which detect s the elect ric lin es of force from the electric potential on the drum. The output of th e sensor de pe nds of th e number of electric lines of force.

Since the output of the sensor is affected by enviro nme nt al conditions, such as temperature and humidity, the sensor output is calibrated du ring proce ss control data initialization.

The drum current detection board ha s two rela y contacts. Usually RA2 grounds the drum. However, during the initialization, the main PCB turns RA1 on and RA2 off and applies the deve lopment bias to the drum shaft.

By measuring the outputs of the drum potentia l sensor when +100 V and +800V are applied to the drum, the sensor output is calibra ted auto mat ically.

2-6

+ 358 hidden pages

Ricoh FT8982, FT680 Service Manual FT8982

Specifications and Main Features

Frequently Asked Questions

User Manual

PREVENTION OF PHYSICAL INJ URY

HEALTH SAFETY CONDITIONS

OBSERVANCE OF ELECTRICAL SAFETY S TANDARDS