Ricoh FW870 User 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 control board has a lithium battery
which can explode if replaced incorrectly. Replace the RAM board
only with an identical one. The manufacturer recommends
replacing the entire RAM board. Do not recharge or burn this
battery. Used RAM board must be handled in accordance with
local regulations.

SAFETY AND ECOLOGICAL NOTES FOR DISPOSAL
1. Do not incinerate the toner cartridge or the used toner. Toner dust may
ignite suddenly when exposed to open flame.
2. Dispose of used toner, developer, and organic photoconductor according
to local regulations. (These are non-toxic supplies.)
3. Dispose of replaced parts in accordance with local regulations.
4. When keeping used RAM boards in order to dispose of them later, do not
put more than 100 RAM boards per sealed box. Storing larger numbers
or not sealing them apart may lead to chemical reactions and heat
build-up.

SECTION 1
OVERALL
MACHINE INFORMATION

1. SPECIFICATIONS
Configuration: Console
Copy Process: Electrostatic transfer system
Original Feed: Sheet feed
Original Size: Maximum: 914 x 3,600 (36" x 142")mm
Minimum: 182 x 257 (B5), 81/2" x 11" lengthwise
Copy Size: Same as "Original Size"
Copying Speed: 7.5 cpm (A1/D sideways)
First Copy: 18 seconds (A1/D sideways)
Warm-up Time: Within 6 minutes (Room temperature 23oC)
Multi-Copy: 1 to 10
Automatic Reset: 2 minutes after copying is finished (can be set
to 1, 3, 4, or 5 minutes or to no auto reset)
Photoconductor: Organic photoconductor drum
Drum Charge: Single-wire with grid plate (Negative Charge)
Reproduction Ratio: 1 : 1 (±0.5%)
Exposure System: Slit exposure via fiber optic array
Exposure Lamp: Fluorescent lamp (26 W)
Development: Dual-component dry toner system
Toner Replenishment: Cartridge system (750 g toner/cartridge)
Toner Consumption: 1,860 A1 or D copies per cartridge (6% original)
Development Bias: Negative
Toner Density Control: Direct toner density detection by induction
sensor
Image Density Adjustment: Development bias control + exposure control
Auto Image Density Control: Development bias control + exposure control
Paper Separation: Dual wire ac corona and pick-off pawls
Cleaning: Cleaning blade
Overall
Information
25 July 1996 SPECIFICATIONS
1-1

Paper Feeding: Manual feed and 2 roll feeds
(3rd roll feeder optional)
Image Fusing: Heat and pressure type, teflon (upper) and
silicone rubber (lower) rollers
Fusing Lamp: Halogen lamp
(115 V: 1,100 W, 230 V: 1,100 W)
Self-diagnostic Codes: 18 codes, displayed in copy counter
Power Source: 115 V/60 Hz....12 A
220 V/50 Hz....7 A
230 V/50Hz.....7 A
240 V/50 Hz....7 A
Power Consumption: Maximum: 1.41 kW
Warm-up: 1.21 kW
Ready: 0.1 to 1.2 kW
Copy cycle: 1.36 kW
Dimensions (W x D x H): 1230 x 690 x 1065 mm
48.4" x 27.2" x 41.9"
Weight: 195 kg, 429 lb
Optional Equipment and Machine Configuration
Configuration Additional equipment
Main frame Optional equipment
A174
copier 3rd Roll feeder (A613) –
Side guides (A569) –
Other Optional Equipment
•Paper Spool (Spare parts)
•Key Counter Bracket Set (A902-15)
•Key Counter (Procured locally)
•Key Counter Holder (Procured locally)
Specifications are subject to change without notice.
SPECIFICATIONS 25 July 1996
1-2

2. PAPER PATH
F

,


,



D
A
B
C
E
A174V502.wmf
A: Original Path  ,  ,  ,  :
Switching back
B: Paper from the manual feed
C: Paper from the roller feed
D: Original Path from Rear Feeder
E: Upper Copy Exit
F: Lower Copy Exit
Overall
Information
25 July 1996 PAPER PATH
1-3

3. DRUM PROCESSES
1. Charge
In the dark the charge corona unit applies a negative charge to the drum.
The grid plate ensures the charge is applied uniformly. The charge remains
on the surface of the drum because the photoconductive drum has a high
electrical resistance in the dark.
2. Exposure
High intensity light from a fluorescent lamp is reflected from the moving
original through the fiber optic array. The charge on the drum surface is
dissipated in direct proportion to the intensity of the reflected light, thus
producing an electric latent image on the drum surface.
1
2
3
4
56
7
8
A174V503.img
DRUM PROCESSES 25 July 1996
1-4

3. Development
The magnetic developer brush on the development roller comes in contact
with the latent image on the drum surface. Toner particles are
electrostatically attracted to the negatively charged latent image areas.
4. Pre-Transfer Lamp
The pre-transfer lamp (PTL) illuminates the drum prior to image transfer. This
reduces the attraction between the toner and the drum, thus making image
transfer easier.
5. Image Transfer
Copy paper is fed to the drum surface, at the exact timing, to align the copy
paper and the developed image on the drum surface. Then a strong negative
charge is applied to the back side of the paper. The negative 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 paper,
reducing the charge on the paper and breaking the electrostatic attraction
between the paper and the drum. Then, the stiffness of the copy paper
causes it to separate from the drum. The pick-off pawls help to separate
paper which has low stiffness.
7. Cleaning
The cleaning blade, which is angled against drum rotation (counter blade
system), removes any toner remaining on the drum surface.
8. Quenching
The light from the quenching lamp electrically neutralizes the surface of the
drum.
Overall
Information
25 July 1996 DRUM PROCESSES
1-5

4. MECHANICAL COMPONENT LAYOUT
1
25
21 2223 24
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
A174V500.wmf
MECHANICAL COMPONENT LAYOUT 25 July 1996
1-6

1. Original Registration Roller
2. Original Feed Roller
3. Copy Tray
4. Exit Rollers
5. Fusing Exit Rollers
6. Hot Roller
7. Pressure Roller
8. Gas Spring
9. OPC Drum
10. T/S Corona Unit
11. Paper Spool
12. 3rd Roll Feeder
13. Cutter Unit
14. Paper Registration Rollers
15. Manual Feed Table
16. Development Unit
17. Toner Cartridge
18. Charge Corona Unit
19. Original Table
20. Original Exit Rollers
21. Original Repeat Roller
22. Exposure Lamp
23. Fiber Optic Array
24. Platen Roller
25. Cleaning Blade
Overall
Information
25 July 1996 MECHANICAL COMPONENT LAYOUT
1-7

5. DRIVE LAYOUT
1. Original Feed Motor
2. Drum
3. Development Unit
4. Development Relay Gear
5. Development Motor
6. Main Motor
7. Drum Drive Relay Gear
8. Transport Unit Drive Belt
9. Fusing Drive Motor
10. Fusing Unit
11. Exit Unit Drive Belt
12. Original Feed Drive Pulley
9
8765
4
3
2
12
11
10
1
A174V501.wmf
DRIVE LAYOUT 25 July 1996
1-8

6. ELECTRICAL COMPONENT DESCRIPTIONS
Refer to the electrical component layout on the reverse side of the Point to
Point (Water proof paper) index numbers.
Name Function Index No.
Motor
Main Motor Drives the drum and the registration roller. (dc motor) 20
Development Motor Drives the development unit components. (dc motor) 22
Fusing Drive Motor Drives the fusing unit components. (dc motor) 2
Original Feed Motor Drives original feed rollers. (dc motor) 25
Roll Feed Motor Drives the 1st, 2nd and 3rd roll feed rollers. (dc motor) 52
Cutter Motor Drives the roll cutter. (dc motor) 56
Exhaust Fan Motor Removes the ozone built up around the drum section
to the ozone filter. (dc motor) 7
Vacuum Motor 1 Provides suction so paper is held firmly on the
transport belt. 19
Vacuum Motor 2 Provides suction so paper is held firmly on the
transport belt. 10
Wire Cleaner Motor Drives the wire cleaner. 24
Magnetic Clutches
Roll Feed Clutch 1 Transmits the roll feed motor drive to the 1st roll feed
roller. 55
Roll Feed Clutch 2 Transmits the roll feed motor drive to the 2nd roll feed
roller. 58
Roll Feed Clutch 3 Transmits the roll feed motor drive to the 2nd roll feed
roller. 54
Registration Clutch Transmits the main motor drive to the registration
roller. 23
Toner Supply Clutch Turns on to supply toner to the development unit. 21
Solenoids
Pick-off Pawl
Solenoid Moves the pick-off pawls against the drum. 66
Exit Gate Solenoid Moves the exit gate to change paper path. 12
Original Gate
Solenoid Moves the original gate to change original path. 1
Switches
Main Switch Supplies power to enable copy operation. 37
Exit Cover Open
Switch Detects whether the exit cover is open or not. 33
Left Cutter Switch Detects whether the cutter unit is at the left home
position or not. 57
Right Cutter Switch Detects whether the cutter unit is at the right home
position or not. 50
3rd Roll Feed Door
Open Switch Detects whether the 3rd roll feed door is open or not. 53
Upper Unit Safety
Switch Cuts ac power when the upper unit is open. 38
Overall
Information
25 July 1996 ELECTRICAL COMPONENT DESCRIPTIONS
1-9

Name Function Index No.
Exit Cover Safety
Switch Cuts ac power when the exit cover is open. 34
Anti-humidify
Heater Switch Supplies power to the anti-humidify heater. 49
Roll Feed Unit
Safety Switch Cuts dc power when the roll feed unit is open. 59
Anti-humidify
Heater Safety
Switch
Cuts power to the anti-humidify heater when the roll
feed unit is open. 48
Sensors
Upper Unit Open
Sensor Detects whether the upper unit is open or not. 45
ADS Sensor Senses the background density of the original. 61
Fusing Exit Sensor Detect paper jams after the registration sensor. 8
Roll Lead Edge
Sensor Detects the leading edge and trailing edge of the paper fed from the roll feeder. 60
Roll End sensor 1 Detects the roll end condition of the 1st roll. 42
Roll End sensor 2 Detects the roll end condition of the 2nd roll. 28
Roll End sensor 3 Detects the roll end condition of the 3rd roll. 54
Original Exit Sensor
1Detects jams in the original exit section. 14
Original Exit Sensor
2Detects jams in the original exit section. 3
Original Exit Sensor
3Detects jams in the original exit section. 18
Original Lead Edge
Sensor Detects the original leading edge to determine the copy process timing. 6
Original Switch
Back Sensor Detects original jams in the repeat copy. 4
Original Set Sensor Detects when an original is inserted from the front
side. 5
Original Feed Unit
Open Sensor Detects whether the original feed unit is open or not. 47
Original
Registration Sensor
Detects the leading edge of the original to
synchronize the original leading edge with the copy
paper. 62
Light Sensor Detects the intensity of the exposure lamp output. 27
Rear Original Set
Sensor Detects when an original is inserted from the rear side. 9
Toner Density (TD)
Sensor detects the density of toner in the developer. 15
Paper Set Sensor Detects when a sheet of paper is set on the by-pass
feed table. 16
Registration Sensor Detects when copy paper arrives at the registration
roller. Detects paper jams. 17
Toner Overflow
Sensor
Detects whether the used toner bottle is full or not.
36
ELECTRICAL COMPONENT DESCRIPTIONS 25 July 1996
1-10

Name Function Index No.
Printed Circuit Boards
Main Board Controls all copier functions both directly and through
other PCBs. 44
AC Drive Board Provides ac power to the lamps, heaters, and PSU. 39
PSU Converts the ac voltage to dc voltage. 43
Operation Panel Informs the CPU of the selected modes, and displays
the situation on the panel. 11
Lamps
Exposure Lamp Provides light to reflect the original’ image onto the
lamp. (fluorescent lamp) 26
Fusing Lamp Provides heat to the hot roller. 32
Pre-transfer Lamp
(PTL) Reduces the charge on the drum surface prior to image transfer. 13
Quenching Lamp
(QL) Neutralizes any charge remaining on the drum surface after cleaning. 65
Power Packs
Charge/Bias/Grid
Power Pack Provides high voltage for the charge corona, grid and development bias. 40
T & S Power Pack Provides high voltage for the transfer corona and
separation. 30
Thermistors
Hot Roller
Thermistor Monitors the hot roller surface temperature. 29
Pressure Roller
Thermistor Monitors the pressure roller surface temperature. 33
Heaters
Anti-humidity Heater Removes humidity from the roll paper. 63
Anti-condensation
Heater Prevents moisture from forming inside the copier. 64
Others
Fusing Thermofuse Protects against fusing overheat. 31
Total Counter Keeps track of the total length of copies made
(Europe) or total number of copies made (U.S.A.). 46
Noise Filter Filters electrical noise on the ac power input lines. 35
FL Regulator Stabilizes the power supplement to the exposure
lamp. 41
Overall
Information
25 July 1996 ELECTRICAL COMPONENT DESCRIPTIONS
1-11

SECTION 2
DETAILED SECTION
DESCRIPTIONS

1. DRUM
1.1 DRUM CHARACTERISTICS
The organic photoconductor (OPC) drum has the following characteristics:
•It is able to accept a high negative electrical charge in the dark. (The
electrical resistance of the OPC drum is high in the absence of light.)
•The electric charge on the drum surface dissipates when the drum is
exposed to light. (The conductivity of the OPC drum is greatly enhanced by
exposure to light.)
•It dissipates an amount of charge that is in direct proportion to the intensity
of the light. That is, where stronger light is directed to the photoconductor
surface, a smaller voltage remains.
The OPC drum used in this model has high sensitivity, good color
reproduction, and good reproduction of low contrast originals (pencil
originals, etc.)
Detailed
Descriptions
25 July 1996 DRUM
2-1

1.2 DRUM DRIVE
The OPC drum [A] is 80 millimeters in diameter and 970 millimeters long. It
turns constantly when the main motor [B] is on.
When the main motor turns on, the drive is transmitted to the drum in the
following way:
main motor drive gear [C] ⇒idle gears [D] ⇒drum drive gear [E] ⇒
drum flange [F] ⇒drum
When the drum knob is tightened, the right flange presses 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.
[D]
[A]
[B]
[C]
[F]
[E]
A174D517.wmf
DRUM 25 July 1996
2-2

2. CHARGE
2.1 OVERVIEW
This model uses a single wire corona unit [A] to charge the OPC (organic
photoconductor) drum [B]. The corona unit generates a corona of negative
ions when a high negative voltage is applied to it by the charge/grid power
pack.
To make the negative corona uniform, a grid consisting of 8 wires is installed
on the charge corona unit between the corona wire and the drum. This grid
drains off any charge in excess of –860 volts, thus preventing fluctuation of
the charge potential.
[B]
[A]
A174D501.wmf
A174D502.wmf
Detailed
Descriptions
25 July 1996 CHARGE
2-3

2.2 CHARGE CORONA CIRCUIT
The main board supplies +24 volts (VAA) to the charge/bias/grid power pack
as the power supply source. Approximately 12 seconds after the copy
process starts, the CPU drops CN102-B7 from 5 volts to 0 volts. This
actuates the dc/dc converter within the power pack which applies a high
negative voltage of approximately –5.0 kV to the charge corona wire. The
corona wire then generates a negative corona charge.
The grid limits the maximum corona charge to –860 volts. This ensures that
the charge does not fluctuate and an even charge is applied to the drum
surface.
The copy grid voltage and charge voltage amounts can be adjusted using
SP# –14 and SP#–13 respectively.
The grid drive signal applied to CN320-4 is a pulse width modulated signal.
As the width of the pulses applied increases, the strength of the grid charge
also increases. The main board monitors the grid charge at CN102-B4 and
controls the width of the drive pulses based on this feedback.
A174D503.wmf
CHARGE 25 July 1996
2-4

2.3 CHARGE WIRE CLEANING MECHANISM
The wire cleaner pads [A] automatically clean the wires every 297 m (500
copies/A1).
The wire cleaner is driven by a dc motor [B]. Normally the wire cleaner is
located at the front end position (home position). After 297 m (500 copies/A1)
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, 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.
[A]
[B]
A174D501-2.wmf
Detailed
Descriptions
25 July 1996 CHARGE
2-5