Ricoh FW830 Service Manual

IMPORTANT SAFETY NOTICES

PREVENTION OF PHYS ICAL INJURY

1. Before disassembling or asse mblin g pa rts of the copie r and perip herals, make sure that the copier power cord is unplu gg ed.

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

3. Note that some compo ne nt s of th e copier and the peripherals are supplied with electrical voltage even if the main switch is turned off.

4. If any adjustment or operat ion check ha s to be made with exterior covers off or open while the main switch is turned on, kee p ha nds away from electrified or mechanically drive n comp on ents.

5. The inside and the met al pa rts of the fusin g un it be come extremely hot while the copier is operat ing . Be careful to avoid touching those components with your bare hands.

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 specifie d intervals.

3. Toner and developer are non-to xic, bu t if you get eith er of them in your eyes by accident, it may cause temp ora ry e ye disco mfo rt. Try to remove with eye drops or flush with wat er as first aid. If un succe ssfu l, ge t med ical attention.

OBSERVANCE OF ELECTRICAL SAFETY STANDARDS

1. The copier and its peripherals must be insta lled and maintained by a customer service represen tative who has completed the training course on those models.

2. The RAM board on the main control board has a lithium battery which can explode if replaced incorre ctly. Re pla ce th e ba tt ery on ly with an iden tica l one. The manufacturer reco mmen ds replacing the entire RAM board. Do not recharge or burn this ba tt ery. Used batteries must be handle d in accordance with local regula tio ns.

SAFETY AND ECOLOGICAL NOTES FOR DISP OS AL

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 tone r, developer, and organic photoconductors according to local regulations. (These are non-toxic supplies.)

3. Dispose of replaced parts in acco rda nce with local regulations.

4. When keeping used lithiu m bat teries in order to dispose of them later, do not put more than 100 batteries per sealed box. Storin g larger nu mbe rs or not sealing them apart may lead to che mical rea ctions and heat build-up.

SECTION 1

OVERALL MACHINE INFORMATION

31 December 1992 SPECIFICATIONS

1. SPECIFICATIONS

Configuration: Table top Copy Process: Electrostatic transfer system Original Feed: Sheet feed Original Size: Maximum: 914 x 3,600 mm

Minimum: 182 x 257 mm (B5 lengthwise) Copy Size: Same as "Original Size" Copying Speed: Manual feed: 6 cpm (A1/D sideways)

Sheet & Roll feed: 7 cpm (A1/D sideways) First Copy: 19 seconds (A1 sideways) Warm-up Time: Within 6.5 minutes (Room temperature 20oC) Multi-Copy: 1 to 10 (A1/D or smaller)

1 to 5 (A0/E) Automatic Reset: 2 minutes after copyin g is finish ed (can be set

to 1, 3, 4, or 5 minutes or to no auto reset) Photoconducto r: Organic photocond uctor drum Drum Charge: Single-wire with grid plate (Negative Charge ) Reproduction Ratio: 1 : 1 (±0.5%) Exposure System: Slit exposure via fiber optic arra y Exposure Lamp: Fluorescent lamp (65 W) Development: Dual-component dry toner system Toner Replenishment: Cartridge system (750 g toner/ca rtridge) Toner Consumption: 1,860 A1 or D copies per cartridge (6% origin al) Development Bias: Negative Toner Density Control: Pattern density detection by photosensor and

direct toner density detection by induction

sensor Image Density Adjustmen t: Development bias contro l + exposu re control Auto Image Density

Control:

Development bias control and exposure control

1-1

SPECIFICATIONS 31 December 1992

Image Transfer: Single wire dc corona (negative charge) with

pre-transfer lamp Paper Separation: Dual wire ac corona and pick-off pawls Cleaning: Cleaning blade Quenching: Photo quenching by LEDs Paper Feeding: Manual feed (sheet and roll feeder optional) Image Fusing: Heat and pressure type, teflon (u pper) an d

silicone rubber (lower) rollers Fusing Lamp: Halogen lamp (115 V: 1,100 W, 220/240 V:

1,100 W) Self-diagnostic Codes: 14 codes, displayed in copy cou nt er

Power Source: 115 V/60 Hz....15 A

220 V/50 Hz....7 A

240 V/50 Hz....7 A

Power Consumption: Maximum: 1.47 kW

Warm-up: 1.25 kW

Ready: 0.1 to 1.2 kW

Copy cycle: 1.42 kW Dimensions (W x D x H): 1,410 x 800 x 600 mm

55.51 x 31.50 x 23.62 in Weight: 180 kg, 397 lb Optional Equip ment: — Sheet feeder

— Roll feeder — Roll feeder connector — Paper spool — Table

1-2

31 December 1992 MACHINE CONFIGURATION

2. MACHINE CONFIGURATION

This copier can be equipped wit h op tio na l equ ipment as show above.

1. Copier (A098)

2. Sheet Feeder (A453)

3. Roll Feeder (A454) and Connector (A384)

4. Roll Feeder (A454) and Sheet Feeder (A453)

1-3

DRUM PROCESSES 31 December 1992

3. DRUM PROCESSES

1. Charge

In the dark the charge coro na unit app lies a ne gative charge to the drum. The grid plate ensures the charg e is app lied unif ormly. The charge remains on the surface of the drum because the photo con du ctive drum has a high electrical resistance in the dark.

2. Exposure

High intensity light from a fluo rescent lamp is reflected from the mo ving original through the fiber optic array. The cha rge on the drum surface is dissipated in direct proportio n to the inte nsit y of th e ref lect ed light , th us producing an electric latent image on the drum surfa ce.

1-4

31 December 1992 DRUM PROCESSES

3. Development

The magnetic developer brush on th e development roller comes in contact with the latent image on the drum surface . Toner particles are electrostatically attracted to the negatively charged latent imag e are as.

4. Pre-Transfer Lamp

The pre-transfer lamp illumina tes the drum prior t o image tra nsf er. This reduces the attraction between the toner and th e drum, thus making image transfer easier.

5. Image Transfer

Copy paper is fed to the drum surf ace , at the exact timing, to align the copy paper and the develope d image on the drum surface. Then a stro ng negat ive charge is applied to the back side of the paper. The negat ive charge pulls the toner particles from the drum surface onto the paper.

6. Paper Separation

A strong ac corona discharge is applied to the back side of the copy pap er, reducing the charge on the pap er an d breaking the electrosta tic at traction between the paper a nd the drum. Then , th e stiffness of the copy paper causes it to separate from the dru m. The pick-off pawls help to separate paper which has low stiffness.

7. Cleaning

The cleaning blade re move s any toner remaining on the drum su rfa ce.

8. Quenching

The light from the quenching lamp electrically neutralizes the surface of the drum.

1-5

MECHANICAL COMPONENT LAYOUT 31 December 1992

4. MECHANICAL COMPONENT LAYOUT

19 20

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31 December 1992 MECHANICAL COMPONENT LAYOUT

1. Front Original Feed Roller

2. Exposure Lamp

3. 1st Press Rollers

4. Fiber Optic Array

5. Platen Roller

6. Charge Corona Unit

7. Cleaning Blade

8. Original Registration Rollers

9. 4th Press Rollers

10. Rear Table Lever

11. 2nd Press Rollers

12. Rear Original Feed Roller

13. 3rd Press Roller

14. Switch Back Gate

15. Hot Roller

16. Upper Exit Rollers

17. Exit Gate

18. Exit Rollers

19. Pressure Roller

20. Transport Belt

21. Pick-off Pawls

22. T/S Corona Unit

23. Paper Registration Rollers

24. Lower Copy Guide

25. Table

26. Roll Feeder

27. Manual Feed Rollers

28. Sheet Feeder

29. Manual Feed Table

30. Original Guides

31. Development Roller

32. Toner Cartridge

33. OPC Drum

34. Original Table

35. 5th Press Roller

36. Original Recycle Gate

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DRIVE LAYOUT 31 December 1992

5. DRIVE LAYOUT

1. Original Drive Belt 2

2. Rear Original Feed Rollers

3. Original Drive Clutch

4. Main Drive Motor

5. Original Registration Rollers

6. Original Drive Belt 3

7. Platen Roller

8. Front Original Feed Rollers

9. Development Roller Gear

10. Auger Gear

11. Toner Supply Clutch

12. Development Motor

13. Paper Feed Clutch

14. Paper Feed Drive Chain

15. Development Drive Belt

16. Paddle Roller Gear

17. Registration Roller Clutch

18. Drum Drive Gear

19. Toner Collection Coil Gear

20. Feed/Fusing Drive Belt 2

21. Fusing Drive Chain

161718

22. Drum Drive Belt

23. Feed/Fusing Drive Belt 1

24. Transport Roller Sprocket

25. Hot Roller Sprocket

26. Exit Roller Drive Chain

27. Lower Exit Roller Sprocket

28. Original Reverse Drive Belt 1

29. Upper Exit Roller Sprocket

30. Original Reverse Drive Belt 2

31. Original Drive Belt 1

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31 December 1992 ELECTRICAL COMPONENT DESCRIPTIONS

6. ELECTRICAL COMPONENT DESCRIPTIONS

Refer to the electrical compone nt layou t on the reverse side of the Poin t to Point (Water proof paper) ind ex nu mbe rs.

Name Function Index. No.

Motors

Main Drives all mechanical components except the

development un it and the fans. (100 Vac) Development Drives the development unit. (100 Vac) 1 Exhaust Fan Removes heat from arou nd the fusin g un it.

(100 Vac) Cooling Fan Provides air flow to the optics cavity. (100 Vac) 6 Vacuum Fan Provides suction so tha t pape r is held firmly

on the transport belts and rollers. (100 Vac)

Magnetic Clutches

Original Forward Feed

Registration Drives the registration rollers. 50 Original Re-

verse Feed

Solenoids

Drives the original forward feed mechanism. 52

Drives the original reverse feed mechanism. 8

Toner Supply Turns on to supply toner to th e de velo pment

unit. Pattern Shutter On ID check cycles, this solenoid turns on to

move the pattern plate into the light path . Exit Gate Controls the position of the exit gate. (When

ON, the paper exits downward; when OFF,

the paper exits upward.) Pick-off Pawl Moves the pick-off pawls again st th e dru m. 34 Paper Stopper Moves the paper stoppe r down to pre vent

paper from being inse rte d. Manual Feed Turns ON to engage the man ua l fee d clut ch. 48 Recycle Gate Cont rols the positio n of the recycle ga te.

(ON = recycle gate in down position,

OFF = recycle gate in up position.)

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ELECTRICAL COMPONENT DESCRIPTIONS 31 December 1992

Name Function Index. No.

Switch Back

Lifts the switch back gate to the up position. 9 Gate

Original Stopper Moves the original stopper down to prevent an

original from being inserted.

Switches

Main Supplies power to the copier. 65 Upper Safety Cuts ac 100 volt power when the upper unit is

opened. Lower Safety Cuts ac 100 volt power when the middle unit

is opened. Rear Safety Cuts ac 100 volt power when the paper exit

unit is opened. Toner Cover Cuts power to the toner sup ply sole no id whe n

the toner cartridge cover is opened . Sheet Feede r

Set

Prevents main motor op era tion when the

sheet feeder is n ot set.

Rear Feeder Detects when the rear feeder table is o pe ned. 21

Sensors

Image Density Detects the image density of the test pattern

on the drum. Toner Density Detects the density of toner in the deve loper. 36 Toner Overflow Detects when the used toner tank is full. 28 Pulse Generator Supplies timing pulses to the main board

(photointerruptor). Original Set Detects when an original is inserted. 41 1st Original

Monitors movement of the origin al. 11 Transport

2nd Original

Monitors movement of the origin al. 14 Transport

Original Registration

Light Detects the intensity of the exposure lamp

Detects when the orig inal lead edge passes

the original registration rollers.

output. Original En-

trance

Detects when an original is inserted from the

rear feeder.

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31 December 1992 ELECTRICAL COMPONENT DESCRIPTIONS

Name Function Index. No.

Switch Back Gate

Detects if the switch back gate moves to the

up position during the original switch back.

Original Exit Detects jams in the original exit section. 39 Recycle Gate De te cts whe ther the recycle gate is in the up

or down position. 1st Feed Detects when copy paper is in sert ed . 38 2nd Feed Detects jams between the manual feed rollers

and the registration rollers. Registration Detects when copy paper arrives at the

registration rollers. Transport Monitors paper movement between the

transfer/separation section and the fusing unit. Fusing Exit Detects jams through the exit unit. 17 Upper Exit Detects jams through the upper exit guid es. 16 Lower Exit Detects jams through the lower exit guides. 18

Printed Circuit Boards

Main Controls all copier functions both dire ctly and

through other PCBs. DC Power

Supply

Provides dc power for all components of the

machine.

AC Controller 1 Provides ac power to the fusing lamp and triac. 57 Lamp Regulator Provides ac power to the fusing lamp. 51 AC Controller 2 Provides ac power to the main motor and

development mot or. Indicator Panel Contains the paper and original insertion

indicators and the original feed stop key. Operation Panel Control the operatio n panel d ispla y. 32 Auto Image

Density

Measures the reflectivity from the origin al’s

background.

Lamps

Exposure Provides light to reflect the original’s image

onto the drum. Quenching Neutralizes any charge remaining on the drum

surface after cleaning.

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ELECTRICAL COMPONENT DESCRIPTIONS 31 December 1992

Name Function Index. No.

Fusing Provides heat to the fusing unit. 53 Pre-Transfer

(PTL)

Reduces the charge on th e drum surface prior

to image transfer.

Power Packs

Charge/Bias/Grid Power Pack

Transfer/ Separation

Provides high voltage power for the charg e

corona, charge grid, an d de velopment bias.

Provides high voltage power for the tran sfe r

corona and separa tion.

Thermistors

Hot Roller Monitors the hot roller’s surfa ce tempe rature. 56 Pressure Roller Mo nit ors th e pressure roller’s surface

temperature. Exposure Lamp Monitors the fluorescent lamp’s temperature. 44

Thermofuses

Fusing Protects against fusing overheat. (Two

thermofuses in parallel.) Exposure Lamp Protects against expo sure lamp overheat. 44

Heaters

Exposure Lamp Warms the scanning lamp. 44 Anticondensa-

Keeps moisture from forming inside the copie r. 47 tion

Others

Total Counter Keeps track of the total length of cop ies mad e. 66 Noise Filter Filters electrical noise on the ac power input

lines. Transformer Steps down the line voltage to 100 Vac. 69 Development

Motor start capacitor. 2 Motor Capacitor

Main Motor Ca-

Motor start capacitor. 3 pacitor

Circuit Breaker Guards against voltage surg es in th e inp ut

power.

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31 December 1992 ELECTRICAL COMPONENT DESCRIPTIONS

Name Function Index. No.

Vacuum Fan Motor Capacitor

Motor start capacitor. 70

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ORIGINAL AND PAPER PATH 31 December 1992

7. ORIGINAL AND PAPER PATH

Repeating Copy Exce pt for A0 /E, A1/D Lengthwise

➀

➁

➂

A: Upper Copy Exit B: Lower Copy Exit

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31 December 1992 ORIGINAL AND PAPER PATH

A0/E, A1/D Lengthwise Switching Back

➀

➂ ➄

➁ ④

⑥

② ③ ④ ⑤ : Switching Back

1-15

SECTION 2

DETAILED SECTION DESCRIPTIONS

31 December 1992 DRUM

1. DRUM

1.1 DRUM CHARACTERISTICS

The organic photoconductor (OPC) dru m has th e followin g cha ract erist ics:

• I t is able to accept a high negative electrical charge in the dark. (The

electrical resistance of the OP C drum is high in the abse nce of ligh t. )

• The electric charge on the drum surface dissip at es whe n th e drum is

exposed to light. (The conduct ivity of the OPC dru m is great ly enh an ced by exposure to light.)

• Dissipating an amount of charge in direct pro po rtio n to the inte nsit y of th e

light. That is, where stronger light is directed to the photoconductor surface, a smaller voltage remain s.

The OPC drum used in this model has high sen sitivit y, go od color reproduction, and good rep rod uction of low contrast originals (pen cil originals, etc.)

2-1

[F]

DRUM 31 December 1992

1.2 DRUM DRIVE

[B]

[E]

[D]

[C]

[G]

[J]

[H]

[I]

[A]

The OPC drum [A] is 80 millimeters in diameter and 970 millimet ers lon g. It turns constantly whe n th e main motor [B] is on.

When the main motor turns on, drive is transmitte d to the drum as follows: main motor drive gear [C] ⇒ idle gear [D] ⇒ main drive pulley gear [E ] ⇒

drum drive belt [F] ⇒ drum drive gear [G] ⇒ drum flange [H] ⇒ drum When the drum knob [I] is tightene d, the rig ht flan ge [J] pre sses firmly against

the drum so that the drum is held tightly between the flanges. The drum and flanges turn together when the main motor is on.

2-2

31 December 1992 CHARGE

2. CHARGE

2.1 OVERVIEW

[A]

[B]

Charge

Grid

This model uses a single wire corona unit [A] to cha rge the OPC (org an ic photoconductor) drum [B ]. The corona wire generates a corona of negative ions when a high negative voltage is applied to it by the charge/ grid power pack [P1].

To make the negative corona unifo rm, a grid consist ing of 8 wires is installed on the charge corona unit betwe en the coron a wire and th e drum. This grid drains off any charge in excess of –940 volts, thus preventing flu ctu ation of the charge potential.

2-3

CHARGE 31 December 1992

2.2 CHARGE CORONA CIRCUIT

Charge / Bias Grid PP

Charge/Bias/Grid PP

DC/DC

Converter

DC/DC

Converter

CN1-1 CN1-2

CN1-3

CN1-6 CN1-10

CN2

-6

CN107

-B14

CN110

-1

-8

DC Power

24V Va

GND

Main Board

Charge

Grid Drive

0/5

Grid monitor

2.5

The DC power supply board supplies +24 volts (Va) to the charge/bias/grid power pack as the power supply source. About 8 seconds afte r t he copy process starts, the CPU drops CN107-B14 from +24 volts to 0 volt. This actuates the dc/dc convert er within the power pack which applies a high negative voltage of approxima te ly – 5.3 kV to the charg e coro na wire. The corona wire then genera te s a neg at ive corona charge.

The grid limits the maximum corona charg e to –94 0 volts. This en sure s t hat the charge does not flu ctu ate and an even charge is applied to th e drum surface. When developing the test pattern for the image density sensor, the grid charge is –460 volts.

The copy grid voltage, and ID senso r grid volt ag e amo unts can be adjusted using service program modes #23 and #22, respectively.

The grid drive signal applied to CN1-6 is a pulse width modulated signal. As the width of the pulses applied increases, the streng th of th e grid charge also increases. The main board mon ito rs t he grid cha rge at CN110-8 and controls the width of the drive pulse s b ase d on this fe ed ba ck.

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[G]

31 December 1992 EXPOSURE

3. EXPOSURE

3.1 OVERVIEW

[A]

[B]

[E]

[F]

[D]

[C]

Light from the expo sure lamp [A] reflects off the original an d through the fiber optics [B] to the OPC drum [C]. The reflector plate [D] aides the exposure lamp intensity for high original moving speed. During exposure, the origin al moves across the exposure glass at the same speed as the drum’s peripheral velocity.

The platen roller [E] presses the original [F] flat against the exposure glass [G] just above the fiber optic array. This ensures that the image is properly focused. (The original must be with in 0. 2 mm of the exp osu re glass surface.)

The exposure lamp is a 100 V, 65 W fluo rescent lamp. This lamp has a heater which prevents a reduction in light outpu t due to low temperatures. The heater maintains the lamp’s temperature at 40oC

2-5

EXPOSURE 31 December 1992

3.2 ORIGINAL FEED

3.2.1 Basic Operation

[A]

[B]

[C]

[F]

[L]

[I]

[H]

[J]

[G]

[K]

[D]

[E]

When the original is inserted on the original table [A ], it activa te s the origin al set sensor [B]. The main moto r t hen tu rns on . Two seco nd s late r t he origin al feed clutch turns on to start turning the front origin al feed rollers [C] , rea r original feed rollers [D], and original registration rollers [E]. The two secon d delay allows time for the operator to alig n the lea d edge of the orig ina l against the first set of rollers to prevent skew.

The original is fed past the 1st and 2nd original transport sensor [F,G] and around the rear original feed rollers to the original registration rollers. The original feed clutch turns off 0.2 second afte r the origin al’s lea din g edge activates the original registratio n sen sor [H] . The origin al rema ins at this position until a sheet of copy pa pe r is fe d.

Just before the copy p aper reaches the registration sensor, the original feed clutch turns on again and original feed resumes. The original passes between the platen roller [I] and the exposure glass [J] and from th ere to the front original feed rolle rs. The origin al’s imag e de nsit y is mea sure d by th e ADS [K] at this time. The original’s image is reflected through the fiber opt i c array to the drum as it passes between the platen roller and the exposure glass.

If making a single copy, the orig inal then exits the machine. However, if making repeat copie s, th e recycle gate [L] directs the original around the front original rollers to the upper part of th e orig inal transport mechanism. The original transport cycle the n rep eats.

The maximum original lengt h fo r repe at copying is 610 millimeters. If the operator attempt s repe at copyin g with an original longer than 610 millimeters, it will automatically feed out aft er makin g a sing le copy.

2-6

31 December 1992 EXPOSURE

The main CPU determines th e original length for synchro cut tin g by counting the generated pulses after the 1st original tran spo rt sensor detects the leading edge of the original until the original set sen sor de tects th e tra iling edge of the original.

Switching-back

[A]

[E]

[D]

[F]

[B]

[G]

[H]

[C]

[I]

The inserted origina l activates both the original se t [A ] an d original exit [B] sensors when the lever [C] is lifted and the entered number of copies is two or more. The copier CPU then detects that the switching -ba ck mode has been entered.

In the switching back mode, the origin al is e xpo sured by passing between the platen roller and exposure glass. At the approp riat e timin g afte r the trailin g edge of the original passes through the 1st orig ina l t ran spo rt sensor [D], the front original feed [E ], plat en [F], origin al reg istration [G], and rear original feed [H] rollers turn backwards and the switch back gate [I] is lifte d to the up position. The original is t ran sported to the machines rear side. At the appropriate timing af ter the trailing edge of the orig ina l p asse s th ro ug h th e registration sensor, th e fro nt origin al fe ed , pla te n, origin al reg istra tion, and rear original feed rollers begin turnin g forward again. The orig ina l is exposed in the exposure section. The copier repeats the switch ing -back operation until the entered numbe r of th e copies have been made. After all the copies are made, the original exits the machine.

The copies exit from the lower co py exit way in the switching-back mode because the rear feeder table is opened.

If the operator attemp ts inserting an original longer than 610 mm witho ut lifting up the rear feeder table lever, the origin al will aut oma tica lly fee d out after being scanned once only.

2-7

[D]

[C]

EXPOSURE 31 December 1992

3.2.2 Drive Mechanism

[D]

[B]

[E]

[A]

[G]

[H]

[I]

[F]

[J]

[K]

[C]

[G]

[H]

[B]

[K]

[E]

[J]

[I]

[F]

[A]

Drive power from the main motor is transmitted to the relay pulley [A]. When the original forward feed clutch [B] is energize d, the rear orig inal feed roller shaft [C] starts turning the original drive belt 3 [D] forward throug h the orig ina l drive belt 2[E]. The front origina l fee d rollers, th e rea r origin al feed rollers, and the original registration rollers rotate in the origin al forward direct ion .

When the original reverse feed clu tch [F] is ene rgize d, the rear original feed roller shaft starts turning the original drive belt 3 backwards from the relay pulley through the int erme dia te gear [G], reverse gear [H], origina l re verse feed clutch shaft [I], and th e orig ina l reverse drive belt 1 and 2 [J, K]. The front original feed rollers, the rea r origin al fe ed rollers, and the origin al registration rollers rotate in the orig ina l re verse direct ion .

2-8

31 December 1992 EXPOSURE

3.3 ORIGINAL STOPPER MECHANISM

[A]

[B]

Originals should not be inserted during a copy cycle. To prevent originals from being inserted, the machine locks the feeler of the original set det ect or in the down position while copying. This is accomplished by the origina l stopper solenoid [A].

When the original stopper soleno id tu rns on , th e stopper arm [B] rotates against the feeler of the original set sensor. This locks the feeler in the down position so that originals can on ly be inse rted as far as the original set sensor.

2-9

EXPOSURE 31 December 1992

3.4 EXPOSURE LAMP CONTROL

[PCB4]

+5V

PWM

CN1-1

CN1-2

CN2-1

CN2-2

LAMP REGULATOR

CN3-1

CN3-2

CN3-4

CN3-5

Lamp OFF (+5V) Lamp ON (GND)

T = 1.0 ms Duty = 15% to 100%

[L1]

Exp. Lamp

The lamp regulator receives 100 volts ac at CN1-1 and CN1-2. It also receives +5 volts, which is used in the lamp regula to r’s cont rol circuit , fro m the main board at CN2-1. The cont rol sign al, which is a pulse width modulated (PWM) signal, is received at CN2-2. The PWM sign al ha s a period (T) of 1 millisecond and a duty of 15% to 100%.

The basic light intensity level is determined eith er by the imag e densit y selected from the operation panel (manual ID con tro l) o r by the origin al’s background level as sensed by the ADS. The CPU uses the light senso r t o monitor the actual light inte nsit y. The light sensor directly senses the lamp’s light output and fe eds a light in te nsity signal back to the main board. This feedback allows the CPU to compensate for variations in light intensity due to the lamp’s age or temperature .

2-10

31 December 1992 EXPOSURE

3.5 MANUAL ID CONTROL VS ADS

Manual ID Level

Light Sensor

Output [V]

Manual ID Level

Light Sensor

Output [V] 1 0.74 14 1.21 2 0.80 15 1.25 3 0.81 16 1.29 4 0.82 17 1.33 5 0.84 18 1.37 6 0.86 19 1.41 7 0.90 20 1.45 8 0.94 21 1.50 9 0.99 22 1.54 10 1.05 23 1.59 11 1.10 24 1.64 12 1.15 25 1.69 13 1.18 26 1.74

3.5.1 Manual ID Control

When in manual image densit y mo de , th e user can select one of 26 manual ID levels. For each level, the intensity of the light output by the exposure lamp (as measured by the light sensor) is fixed. This is shown in the above table. For manual ID levels 2 thro ugh 12 , th e de velo pment roller bias also varies. (See the section on development bias.)

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+ 197 hidden pages

Ricoh FW830 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

PREVENTION OF PHYS ICAL INJURY

HEALTH & SAFETY CONDITIONS

SAFETY AND ECOLOGICAL NOTES FOR DISP OS AL

OVERALL MACHINE INFORMATION

DETAILED SECTION DESCRIPTIONS