Ricoh FT7650, FT660 Service Manual

IMPORTANT SAFETY NOTICES

PREVENTION OF PHYSICAL INJURY

1. Before disassembling or assembling parts of the copier and peripherals, make sure that the copier power cord is unplugged.

2. The wall outlet should be near the copier and easily accessible.

3. Note that some components of the copier and the paper tray unit are supplied with electrical voltage even if the main switch is turned off.

4. If any adjustment or operation check has to be made with exterior covers off or open while the main switch is turned on, keep hands away from electrified or mechanically driven components.

5. The inside and the metal parts of the fusing unit become extremely hot while the copier is operating. Be careful to avoid touching those components with your bare hands.

6.The copier is not attached to the table. Pushing the copier too heard may cause it to drop onto the floor. While moving the copier, push the table.

7. When the main switch is tuned on, the machine will suddenly start turning to perform the developer initialization. Keep hans away from any mechanical and electrical components during this period.

HEALTH SAFETY CONDITIONS

1. Never operate the copier without the ozone filters installed.

2. Always replace the ozone filters with the specified ones at the specified intervals.

3. Toner and developer are non-toxic, but if you get either of them in your eyes by accident, it may cause temporary eye discomfort. Try to remove with eye drops or flush with water as first aid. If unsuccessful, get medical attention.

OBSERVANCE OF ELECTRICAL SAFETY STANDARDS

1. The copier and its peripherals must be installed and maintained by a customer service representative who has completed the training course on those models.

CAUTION



2. The RAM board on the main con trol board has a lithium battery which can explode if replaced incorrectly. Replace the RAM board only with an identical one. The manufacturer recommends replacing the entire RAM board. Do not recharge or burn this battery. Used RAM board must be handled in accordance with local regulations.

SAFETY AND ECOLOGICAL NOTES FOR DISPOSAL

1. Do not incinerate the toner cartridge or the used toner. Toner dust may ignite suddenly when exposed to open flame.

2. Dispose of used toner, developer, and organic photoconductor according to local regulations. (These are non-toxic supplies.)

3. Dispose of replaced parts in accordance with local regulations.

4. When keeping used RAM boards in order to dispose of them later, do not put more than 100 RAM boards per sealed box. Storing larger numbers or not sealing them apart may lead to chemical reactions and heat build-up.

SECTION 1

OVERALL MACHINE

INFORMATION

15 July 1996 SPECIFICATION

1. SPECIFICATION

Configuration: Console Copy Process: Dry electrostatic transfer system Toner Supply Control: Fuzzy Control Photoconductor: OPC drum Originals: Sheet/Book Original Size: Maximum A3/11" x 17" Original Alignment: Left rear corner Copy Paper Size: Maximum A3/11" x 17"

Minimum A5/5

B5/8 A6/5

1/2 1/2 1/2

1/2

" x 8

" (Tray)

" x 11" (1.5 k LCT)

1/2

" x 8

" (By-pass)

Duplex Copying: Maximum A3/11" x 17"

Minimum A5/5

1/2

" x 8

1/2

" (sideways)

Copy Paper Weight: Paper tray: 52 ~ 128 g/m

Bypass feed table: 52 ~ 157 g/m Duplex copying: 64 ~ 104 g/m

, 14 ~ 34 lb

, 14 ~ 42 lb

, 17 ~ 24 lb

Overall

Information

Reproduction Ratios: 4 Enlargement and 6 Reduction

A4/A3 Version LT/LDG Version

200%

Enlargement

Full Size 100% 100%

Reduction

141% 122% 115%

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

200% 155% 129% 121%

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

1-1

SPECIFICATION 15 July 1996

Power Source: 115 V, 60 Hz, more than 20 A (for N.A)

220 ~ 240 V, 50 Hz/60 Hz, more than 10 A (for Europe and Asia)

Power Consumption: A175 copier

Copier only Full system*

Warm-up 1.20 kVA 1.22 kVA Stand-by 0.22 kVA 0.24 kVA

Copying 1.40 kVA 1.40 kVA

Maximum 1.70 kVA 1.75 kVA

A176/A191 copiers

Copier only Full system*

Warm-up 1.20 kVA 1.22 kVA Stand-by 0.22 KVA 0.24 kVA

Copying 1.50 kVA 1.50 kVA

Maximum 1.70 kVA 1.75 kVA

A177/A192 copiers

Copier only Full system*

Warm-up 1.20 kVA 1.22 kVA Stand-by 0.22 kVA 0.24 kVA

Copying 1.60 kVA 1.60 kVA

Maximum 1.70 kVA 1.75 kVA

*Full System:

Mainframe with dual job feeder, floor type

•

sorter stapler and 3,500-sheet large capacity tray

Mainframe with recirculating document

•

handler, finisher and 3,500-sheet large capacity tray

1-2

15 July 1996 SPECIFICATION

Noise Emission: Sound Pressure Level:

The measurements are made according to ISO7779

A175 copier Sound pressure level

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

Stand-by less than 34 dB (A)

Copying less than 57 dB (A) (average)

Copier only

Overall

Information

Sound power level

A176/A191 copiers Sound pressure level

Sound power level

A177/A192 copiers Sound pressure level

(The measurements are made according to ISO 7779.)

Copier only

Stand-by less than 48 dB (A)

Copying less than 70 dB (A) (average)

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

Stand-by less than 34 dB (A)

Copying less than 59 dB (A) (averag e)

(The measurements are made according to ISO 7779.)

Stand-by less than 48 dB (A)

Copying less than 73 dB (A) (average)

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

Stand-by less than 36 dB (A)

Copying less than 59 dB (A) (average)

Copier only

Sound power level

(The measurements are made according to ISO 7779.)

Copier only

Stand-by less than 50 dB (A)

Copying less than 73 dB (A) (average)

1-3

SPECIFICATION 15 July 1996

Dimensions:

Width Depth Height

Copier only 690 mm

27.2"

Copier with dual job feeder, sorter stapler, and 3,500-sheet large capacity tray

Copier with dua l jo b fe eder, sorter stapl er w i th punch, and 3,500- sheet large capacity tray

Copier with reci r cul ating document handler, finisher, and 3 ,5 00-sheet large ca pacity tray

1,659 mm

65.4"

1,659 mm

65.4"

1,764 mm

65.9"

690 mm

27.2"

690 mm

27.2 mm" 690 mm

27.2"

690 mm

27.2"

980 mm

38.6"

1,116 mm

43.9"

1,113 mm

43.9

1,112 mm

43.8"

Weight: Copier only:(Without the optional platen cover

= Approximately 2 kg) A175 copier: Approximately 161 kg A176/A177 copiers: Approximately 164 kg A191/A192 copiers: Approximately 167 kg

Zoom: From 50% to 200% in 1% steps Copying Speed:

A175 copier

A176/A191

copiers

A177/A192

copiers

A4/LT (sideways) A3/DLT B4/LG

51 (A4 others) 50 (A4/in France) 50 (LT)

60 31 38

70 36 44

26 32

Warm-up Time: Less than 5 minutes (20°C) (A175 copier)

Less than 5.5 minutes (20°C) (A176/A177/A191/ A192 copiers)

First Copy Time: (A4/81/2: x 11" sideways

3.1 seconds (A175 copier)

2.6 seconds (A176/A177/A191/A192 copiers)

from the 1st feed station)

Copy Number Input: Number keys, 1 to 999 (count up or count down) Manual Image Density

7 steps

Selection: Automatic Reset: 1 minute standard setting; can also be set from 1

second to 999 seconds or no auto reset.

1-4

15 July 1996 SPECIFICATION

Copy Paper Capacity:

By-pass feed table: approximately 50 sheets

•

Paper tray: approximately 550 sheets

•

Tandem tray: approximately 500 sheets

•

Large capacity tray: approximately 1500

•

sheets

Toner Replenishment: 1,100 g/cartridge Optional Equipment:

Platen cover (A528-04)

•

Dual job feeder (A610)

•

Recirculating document handler (A607)

•

20 bin sorter stapler (Floor type) (A606-17:

•

Ricoh, -22: NRG, -15: Savin, -26: Infotec) Finisher (A608)

•

3500-sheet Large capacity tray (A609)

•

Receiving Tray (A446-05)

•

Key Counter Bracket D (A509-03)

•

20 bin sorter stapler (Floor type) with punch

•

(A606-57, -67: Ricoh, -52, -62: NRG -66: Infotec, -55: Savin)

Overall

Information

Guidance ROM KIT (A627)

•

Editing sheet (spare part)

•

1-5

MACHINE CONFIGURATION 15 July 1996

2. MACHINE CONFIGURATION

2.1 COPIER OVERVIEW

There are three types of mainframe.

A175 copier

Four 550-sheet paper trays

Optional 3,500-sheet large capacity

tray

550 550

(3,500)

550 550

A176V500.img

A176/A177 (U.S.A., Asia) copiers

Tandem paper tray

(including two 500-sheet paper tray)

One 550-sheet paper tray

1,500-sheet built-in large capacity

tray

Optional 3,500-sheet large capacity

tray

500 x 2 or 500

(3,500)

550

1,500

A176V501.img

1-6

15 July 1996 MACHINE CONFIGURATION

A191/A192 (Europe) copiers

Tandem paper tray

Three 550-sheet paper trays

Optional 3,500-sheet large capacity

tray

500 x 2 or 550

(3,500)

550 550 550

A176V500.img

Overall

Information

1-7

MACHINE CONFIGURATION 15 July 1996

2.2 SYSTEM OVERVIEW

DJF version

(Mainframe type (A175/A176/A177 (U.S.A.), A175/A191/A192 (EU)) with dual job feeder and floor type sorter stapler. The mainframe in the illustration below is the A176.)

Dual job feeder (A610)

Floor type sorter stapler (A60617) or

3,500-sheets large capacity tray (A609)

Floor type sorter stapler with punch (A60657, A60667)

A176V502.img

RDH version

(The mainframe (A175/A176/A177 (U.S.A.), A175/A191/A192 (EU)) with recirculating document handler and finisher. The mainframe in the illustration below is the A176.)

Recirculating document handler (A607)

Finisher

(A608)

3,500-sheets large capacity tray (A609)

A176V503.img

1-8

15 July 1996 MACHINE CONFIGURATION

MEMO

Overall

Information

1-9

COPY PROCESS AROUND THE DRUM 15 July 1996

3. COPY PROCESS AROUND THE DRUM

A176V504.wmf

1. OPC DRUM

The organic photo conductive (OPC) drum (100 mm diameter) has high resistance in the dark and low resistance under light.

2. DRUM CHARGE

In the dark, the charge corona unit gives a uniform negative charge to the OPC drum. The charge remains on the surface of the drum. The amount of negative charge on the drum is proportional to the negative grid bias voltage applied to the grid plate on the charge corona unit.

3. EXPOSURE

An image of the original is reflected to the OPC drum surface via the optics section. The charge on the drum surface is dissipated in direct proportion to the intensity of the reflected light, thus producing an electrical latent image on the drum surface.

The amount of charge remaining as a latent image on the drum depends on the exposure lamp intensity controlled by the exposure lamp voltage.

4. ERASE

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

1-10

15 July 1996 COPY PROCESS AROUND THE DRUM

5. DRUM POTENTIAL SENSOR

The drum potential sensor detects the electric potential on the drum to compensate image processing elements.

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.

Overall

Information

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.

1-11

MECHANICAL COMPONENT LAYOUT 15 July 1996

4. MECHANICAL COMPONENT LAYOUT

511

39 38

12 13

15 16 17 18

19 20 21

22 23

24 25

1-12

26 27

A176V505.wmf

15 July 1996 MECHANICAL COMPONENT LAYOUT

Overall

Information

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

22. Registration Rollers

23. Transfer Belt

24. Vertical Transport Rollers

25. Tandem Tray 550-sheet Tray

26. Universal Tray

27. 1500-sheet LCT 550-sheet Tray

28. Toner Collection Bottle

29. Transfer Belt Cleaning Blade

30. Hot Roller

31. Pressure Roller

32. Jogger Fences

33. Duplex Positioning Roller

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

34. Duplex Pick-up Roller

35. Duplex Feed Roller

36. Separation Belt

37. Junction Gate

38. Exit Rollers

39. Optics Cooling Fan

40. 550-sheet Tray

1-13

DRIVE LAYOUT 15 July 1996

5. DRIVE LAYOUT

❶

❷

❾

❽

❼

3 4 5

❸

❻

❺

❹

Main Motor

❶

Scanner Drive Motor

❷

Fusing/Duplex Drive Motor

❸

Paper Feed Motor

❹

Toner Collection Motor

❺

Registration Clutch

❻

By-Pass Feed Motor

❼

BY-Pass Feed Clutch

❽

Development Drive Motor

❾

A176V506.wmf

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

1-14

15 July 1996 PAPER PATH

6. PAPER PATH

6.1 STANDARD COPYING

[F]

[E]

[D]

[C]

[B]

[A]

Overall

Information

A176V507.wmf

Paper feed begins from the exterior LCT, by-pass feed table or paper feed stations in the paper tray unit. The copy paper then follows one of two paths inside the copier. The path followed depends on which mode the operator has selected. For copy processing, all sheets follow the same paths from the paper feed mechanism [A] through the registration rollers [B], transfer belt [C], and fusing unit [D]. After that, copies are delivered to the sorter bins [E] or proof tray [F], however, 2 sided copies are diverted for further processing.

1-15

PAPER PATH 15 July 1996

6.2 MULTIPLE 2-SIDED CO PYI NG

a. Front Side

[D]

[A]

[B]

[C]

A176V508.wmf

b. Rear Side

A176V509.wmf

In this mode the junction gate [A] directs sheets exiting the fusing unit to the duplex tray entrance. After that, all sheets follow the path through the duplex entrance rollers [B].

After all front side copying is completed, the sheets on the duplex tray are fed in order from the bottom to the top and follow the path through the duplex feed mechanism and vertical transport rollers [C] to the registration rollers [D]. After that, these sheets follow the same path as standard copying from the registration rollers to the sorter.

1-16

15 July 1996 ELECTRICAL COMPONENT DESCRIPTION

7. 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 Name Function Index No.

Motors

M2 M3 Main Drives the main unit components. 44

M4 Develop ment Drive Drives the development unit. 45 M5 By-pass Fe ed Drives the by-pass feed rollers. 46 M6 3rd Scanne r Dr i ve Drives the 3rd scanner (dc steppe r) 47

M10 Lens Horizontal Drive Shi f ts the lens horizontal position. 51 M11 Lens Vertical Drive Shifts the lens vertical position. 52 M12 Optic Cooling Fan Removes heat from the optics unit . 53

M13

M14

M15

M16

M17

M18

M19

M20

M21

Scanner Drive Drives the 1st and 2nd scanners (dc

servo).

Exhaust Fan Removes the heat fr om ar ound the

fusing unit.

Toner Bottle Drive Rotates the toner bottle to supply

toner to the toner hopper.

Charge Wire Cleaner Drive

Jogger Drives the jogger fences to square the

Fusing/Dupl ex Drive Drives the fusin g uni t , the duplex unit,

Paper Feed Drives all feed and transpor t rol l ers in

1st Lift Raises the bottom plate in the 1st

2nd Lift Raises the bottom plate in the 2nd

Toner Collec tion Transports the col l ected toner to the

3rd Lift (4 Tray version only)

Side Fence Drive (Tandem vers i on only)

Rear Fence Drive (Tandem vers i on only)

LCT Motor (1,500 Tray ver si on only)

Drives the main charge wire cleaner to clean the charg e w i re .

paper stack in the duplex tray (dc stepper).

and the paper exi t r ol le r s.

the paper tray uni t.

paper tray.

toner collecti on bottle. Raises the bottom plate in the 3rd

paper tray. Opens and closes the front and the

rear side fences of th e ta ndem tray. Moves the paper s st acked in the left

tandem tray to the right tandem tray. Lifts and lowers the LCT bottom plate

to bring paper to t he f eed position and allow loading of the paper.

127

Overall

Information

1-17

ELECTRICAL COMPONENT DESCRIPTION 15 July 1996

Symbol Name Function Index No.

M22

M23

M24

M25

M26

AC Drive Cooling Fan (60/70 CPM version only)

Optic Cooli ng Fan-2 (60/70 CPM version only)

Duplex Cool i ng Fan Cools the paper on the duplex tray to

Drum Cooling Fan (70 CPM versio n onl y)

4th Lift (4 Tray version only)

Remove heat from around the AC drive unit.

Remove heat from the optic unit.

reduce the heat around the drum. Cools the drum unit t o remove the

heat from the duplex tray. Raises the bottom plate in the 4th

paper tray.

141

142

*143A, B

144

151

* (A: 60/70 CPM, B: 50/5 1 C P M )

Magnetic Clutches

MC1

Toner Supply Turns the toner supply ro l le r to supply

toner to the devel opment un it.

57 MC2 Registration Drives the r egi stration rollers. 58 MC3

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

feed table.

Duplex Transport D rives the duplex transport rollers to

MC4

transport the pap er to the vertical

transport rollers.

MC5

MC6

MC7

MC8

MC9

Duplex Feed Starts paper feed from the dupl ex tray

to the du plex transport rollers.

1st Feed Starts paper feed from the 1st feed

tray.

2nd Feed Starts paper feed from the 2nd feed

tray.

3rd Feed Starts paper feed from the 3rd feed

tray.

4th Feed (4 Tray version only)

Starts paper feed from the 4th feed tray.

101

104

152

Switches

SW1

SW2

SW3

SW4

SW5

By-pass Table Det ect s i f the by-pass feed table is

open or closed.

Front Door Safety Cuts the ac power line and detect s i f

the front door is open or not.

1st Tray Set

Detects if the 1st tray is set or not. (Non-Tandem version only)

2nd Paper Size Determines what size paper i s i n th e

2nd (universal) paper tray. Toner Overflow Detects w hen the toner collection

bottle is full.

1-18

15 July 1996 ELECTRICAL COMPONENT DESCRIPTION

Symbol Name Function Index No.

SW6 SW7 Lo w er F ront Door Safety Detects if the front door is open or not. 83 SW8 SW9 Mai n Provides powe r to the copier 122

SW10

SW11

Solenoids

SOL1

SOL2

SOL3

SOL4

SOL5

SOL6

SOL7

SOL8

SOL9

SOL10

SOL11

SOL12

Toner Collection Bottle Set

3rd Tray Set (4 Tray version only)

Tray Down (1500 Tray vers i on only)

4th Tray Set (4 Tray version only)

Junction Gate Moves the junction gate to direct

Duplex Positioning Controls the up-down movem e nt of

By-pass Pick-u p Controls the up-down movem ent of

Guide Plate Opens the guide plate when a pap er

Transfer Belt Posi tio ni ng Controls the up-d ow n m ovement of

Pressure Arm Presses th e paper on the dupl ex t ray

Tandem Lock Locks the left tandem feed tray and

1st Pick-up Controls the up-down movem ent of

1st Separation Rol l er Controls the up-d ow n m ovement of

2nd Pick-up Controls the up-down movement of

2nd Separatio n R ol l er Controls the up-down movement of

3rd Pick-up Controls the up-down movement of

Detects if the toner collection bottle is

set or not.

Detects if the 3rd tray is set or not.

Lowers the LCT bot t om pl at e.

Detects if the 4th tray is set or not.

copies to the duplex tray or to the

paper exit.

the positioning roller.

the pick-up rol l er for by- pass feed.

misfeed occurs around th is area.

the transfer belt unit.

against the dupl ex feed rollers.

separates the ri ght and left tandem

trays.

the pick-up rol l er in the 1st feed

station.

the separation r ol l er i n the 1st feed

station.

the pick-up roller in the 2nd feed

station.

the separation r ol l er i n the 2nd feed

station.

the pic k-up roller in the 3r d f eed

station.

126

149

100

102

103

105

Overall

Information

1-19

ELECTRICAL COMPONENT DESCRIPTION 15 July 1996

Symbol Name Function Index No.

3rd Separation Ro ll er Controls the up-down movement of

SOL13

the separation r ol l er i n the 3rd feed

106

station.

SOL14

4th Pick-up (4 Tray version only)

Controls the up-down movement of

the pic k-up roller in the 4t h f eed

153

station.

SOL15

4th Separation Rol l er (4 Tray version only)

Controls the up-down movement of

the separation r ol l er i n the 4th feed

154

station.

Sensors

Scanner HP Informs the CPU when the 1st and

2nd scanners are at th e home position .

Platen Cover Position-1 Informs the CPU that the platen cover

is in the up or down po sition (related

to APS/ARE function). Platen Cover Position-2 Informs the CPU that the platen cover

is in the up or down po sition to detect

if the original has been removed or not.

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

full-size posi t i on. Lens Horizont al H P Informs the CPU t hat th e l ens is at the

horizontal home position. 3rd Scanner HP Informs the CPU when the 3rd

scanner is at the hom e position. By-Pass Paper End Informs the CPU that there is no

paper in the by-pass feed table. Guide Plate Position Informs the CPU if the registration

guide plate is closed or not. Jogger HP Detects if the duplex jogger fen ces

are at the home po si t i on or not .

Vertical Transport Detects the leading edge of the paper

S10

to determine the paper feed timi ng of

the next sheet. Duplex Exit Detects the leadi ng edge of the paper

S11

to determine the duplex transpor t

clutch on timing. Duplex Entranc e Sensor Detects the leadi ng edge of the paper

S12

to determine the duplex feed clut ch off

timing.

S13 Duplex Paper End Detects paper in the dup l ex t ra y. 13

Duplex Transport D et ect s t he l eading edge of t he paper

S14

to control the jogger motor and the

positioning sol enoid on timing.

S15 Exit Detects misfee ds. 15

1-20

15 July 1996 ELECTRICAL COMPONENT DESCRIPTION

Symbol Name Function Index No.

S16 Fusing Exit Detects misfeeds. 16 S17 Paper Guide Detects misfeeds. 17

S18 S19 Original Length-1 Detects original length. 21

S20 Original Length-2 Detects original length. 22 S21 Original Width Detect s or i gi nal width. 23

S22

S23

S24 S25 Toner Near End Detects toner end condi t i on. 30 S26 S27 Drum Potential Detects the drum surface potentia l . 39 S28

S29

S30

S31

S32

S33

S34

S35

S36

S37

S38

S39

Auto Image Density Senses the background density of the

original.

By-Pass Paper Size Informs the CPU what size paper is in

the by-pass feed table. Toner Density Senses t he amount of toner in the

black develop er . Registratio n Detects misfeeds and control s

registration clutch off-on tim ing.

Auto-Response Returns the displ ay from the scree n

saver.

Image Density Detects the density of th e ID sensor

pattern on the drum. 1st Pape r End Informs the CPU when the 1st

cassette runs ou t of paper. 1st Pape r Near End I nforms the CPU when t he 1st

cassette is in nea r end condition. 1st Paper Feed Controls t he 1st paper feed clu tc h

off/on timing and the 1st pick-up

solenoid off ti m i ng. 2nd Paper Near End Informs the CPU when the 2nd

cassette is in nea r end condition. 1st Lift Detects the correct feed height of th e

1st cassette. 2nd Paper End Informs the CPU when the 2nd

cassette runs ou t of paper. Toner Collec tion Motor Detects the toner col l ect i on motor

operation. 2nd Lift Detects the correct feed height of th e

2nd cassette. 3rd Lift Detects the correct feed height of the

3rd cassette. 3rd Paper Near End

(4 Tray version only) 3rd Paper End Informs the CPU when the 3rd

Informs the CPU when the 3rd

cassette is in nea r end condition.

cassette runs ou t of paper.

Overall

Information

1-21

ELECTRICAL COMPONENT DESCRIPTION 15 July 1996

Symbol Name Function Index No.

3rd Paper Feed Controls the 3rd paper feed clutch

S40

off/on timing and the 3rd pick-up

solenoid off ti m i ng. 2nd Paper Feed Controls the 2nd paper feed clut ch

S41

off/on timing and the 2nd pick-up

solenoid off ti m i ng.

S42

Base Plate Down (Tandem vers i on only)

Detects when the bottom plate is

completely lowered to stop the 1st lift

motor.

S43

S44

S45

S46

S47

S48

S49

S50

S51

S52

S53

S54

Side Fence Positioning (Tandem vers i on only)

Rear Fence Retur n (Tandem vers i on only)

Rear Fence HP (Tandem vers i on only)

Left Tandem Paper En d (Tandem vers i on only)

LCT Near End (1,500 Tray ver si on only)

Tray Down (1,500 Tray ver si on only)

Tray Paper Set (1,500 Tray ver si on only)

Side Fence Close (Tandem vers i on only)

4th Lift (4 Tray version only)

4th Paper Near End (4 Tray version only)

4th Paper End (4 Tray version only)

4th Paper Feed (4 Tray version only)

Informs the CPU when the tandem

tray side fences are open.

Informs the CPU when the tandem

tray rear fence is i n th e return position.

Informs the CPU when the tandem

tray rear fence is i n th e home position .

Informs the CPU when the left tandem

tray runs out of paper.

Detects the paper near end conditi on.

Detects when the tray is completely

lowered to stop the LCT motor.

Informs the CPU when the paper is

set on the LCT botto m tr ay.

Detects whether the side fence close

or not.

Detects the correct feed height of th e

4th cassette.

Informs the CPU when the 4th

cassette is in nea r end condition.

Informs the CPU when the 4th

cassette runs ou t of paper.

Controls the 4th pa per feed clutch

off/on timing and the 4th pick-up

123

124

125

150

145

146

147

148

solenoid off ti m i ng.

PCBs

PCB1

AC Drive Provides AC power to the exposure

lamp and fusing lamp.

PCB2 Main Controls all machine functions. 109 PCB3 Optic Con trol Controls all op tics components. 110

PCB4

PCB5

Development Bi as Control

Paper Feed Cont rol Controls all components i n t he paper

Controls the outp ut of development

bias.

bank.

1-22

108

111

112

15 July 1996 ELECTRICAL COMPONENT DESCRIPTION

Symbol Name Function Index No.

PCB6 DC Power Supply Unit Provides DC power. 113 PCB7 Guidance Controls the guidance display. 120

PCB8

Lamps

L1 L2 Fusing Provides heat to the hot roller. 32 L3

Operation Panel Controls the LED matrix, and monitors

the key matrix.

Exposure Applies high intensity light to the

original for exposure.

Quenching Neutralizes any charge remaining on

the drum surface a fter cl eaning. Erase Discha r ges the drum outside the

image area. Pre-transfer Reduces the charge on the drum

surface before tr ansfer.

121

Overall

Information

Power Packs

Transfer Provides high voltage for the transfer

PP1

Charge Provides high vo ltage fo r t he charge

PP2

Others

TS1

TF1

TH1

TH2

TH3

RA1 Main Power Relay Controls main power. 107

Optics Therm oswitch Opens the exposure lam p ci r cui t i f the

Fusing Therm of u se Opens the fusing lamp circuit i f the

Fusing Therm i st or Senses the tempera ture of the hot

Optics Therm i st or Monitors the temperature of the optics

Drum Thermistor (Located on the ID Sensor Ass’y)

Transfer Anti-Condensation

Optics Anti-Condensation Turns on when the main switch is off

belt and controls t he t ransfer belt

positioning solenoid.

corona wires, and t he grid plate.

Controls QL, PTL, and charge wire

cleaner motor functions.

optics unit overheats.

fusing unit overheats.

roller.

cavity.

Monitors the temperature of the OPC

drum. 41

Turns on when the main switch is off

to prevent moisture from forming on

the transfer belt.

to prevent moisture from forming on

the optics.

117

119

1-23

ELECTRICAL COMPONENT DESCRIPTION 15 July 1996

Symbol Name Function Index No.

CO1 NF1 Noise Filter Removes ele ct rical noise. 115

CB1

LA1

Total Counter Keeps track of the total number of

copies made.

Circuit Breake r Provides back-up high current

protection for the electrical

components. Lightening Arrestor Removes current surges from the AC

input lines.

114

116

118

1-24

SECTION 2

DETAILED SECTION

DESCRIPTIONS

15 July 1996 PROCESS CONTROL

1. PROCESS CONTROL

1.1 OVERVIEW

Image Density Control

ADS Pattern

Original Scale

(Fuzzy Control)

Pattern

Latent Image Control

Detailed

Descriptions

Latent image Control

Exposure Control

Charge Control

Drum Thermistor

Lamp Voltage

Grid Voltage

Paper

Pattern

VL Pattern

Original Exposure Glass

Erase Lamp

Drum Potential Sensor

Toner Supply On time

Development. Bias

TD Sensor

ID Sensor

Image Density Control

(Fuzzy Control)

Toner Supply Control

Main PCB

A176D500.wmf

This model uses two process control methods. One compensates for variation in the drum potential (latent image control) and the other controls the toner concentration and toner supply amount (image density control).

2-1

PROCESS CONTROL 15 July 1996

1.1.1 Latent Image Control

Charge

Exposure

Black

White

Erase

A176D501.wmf

Potential Sensor

Drum

The figure shows the changes of the drum potential during the copy process.

: The drum potential just after charging the drum.

(Dark Potential): The drum potential just after exposing the black

pattern (V

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

pattern (V

(Residual Voltage): The drum potential just after the exposure of the

pattern)

erase lamp.

After long usage following installation or a PM, drum potential will gradually increase due to the following factors:

Dirty optics or exposure lamp deterioration Dirty charge corona casing and grid plate Change of the drum sensitivity

In this copier, the change in drum potential is detected by the drum potential sensor and the following items are controlled to maintain good copy quality.

The grid bias voltage The exposure lamp voltage The development bias voltage.

A drum thermistor detects the drum temperature and this data is also used to control the above voltages. It is impossible to explain simply because it is controlled by methods developed in our laboratories using an artificial neural network.

2-2

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