Ricoh VT3500 S Service Manual vt6000

IMPORTANT SAFETY NOTICES

PREVENTION OF PHYSICAL INJURY

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

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

3. 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.

HEALTH SAFETY CONDITIONS

1. If you get ink in your eyes by accident, try to remove it with eye drops or flush
with water as first aid. If unsuccessful, get medical attention.

2. If you ingest ink by accident, induce vomiting by sticking a finger down your
throat or by giving soapy or strong salty water to drink.

OBSERVANCE OF ELECTRICAL SAFETY STANDARDS

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

CAUTION



The RAM board has a lithium battery which can explode if handled
incorrectly. Replace only with the same type of RAM board. Do not
recharge or burn this battery. Used RAM boards must be handled in
accordance with local regulations.

ATTENTION



La carte RAM comporte une pile au lithium qui présente un risque
d'explosion en cas de mauvaise manipulation. Remplacer la pile
uniquement par une carte RAM identique. Ne pas recharger ni brûler cette
pile. Les cartes RAM usagées doivent être éliminées conformément aux
réglementations locales.

SAFETY AND ECOLOGICAL NOTES FOR DISPOSAL

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

2. Used ink and masters should be disposed of in an envionmentally safe manner
and in accordance with local regulations.

3. When keeping used lithium batteries (from the main control boards) in order to
dispose of them later, do not store more than 100 batteries (from the main
control boards) per sealed box. Storing larger numbers or not sealing them
apart may lead to chemical reactions and heat build-up.

TABLE OF CONTENTS

1. OVERALL MACHINE INFORMATION .........................................1-1

1.1 SPECIFICATIONS................................................................................... 1-1

1.2 MAJOR DIFFERENCES BETWEEN THE C223 AND THE C228............. 1-4

2. DETAILED SECTION DESCRIPTIONS........................................2-1

2.1 MASTER EJECT...................................................................................... 2-1

2.2 MASTER FEED........................................................................................ 2-2

2.2.1 MASTER FEED MECHANISMS...................................................... 2-2

2.2.2 THERMAL HEAD PRESSURE RELEASE MECHANISM................ 2-4

2.3 PAPER FEED .......................................................................................... 2-5

2.3.1 PAPER FEED ROLLER................................................................... 2-6

2.3.2 PAPER SEPARATION PLATE........................................................ 2-7

2.4 PRINTING................................................................................................ 2-8

2.4.1 OVERVIEW..................................................................................... 2-8

Printing Pressure Cam........................................................................ 2-8

Paper Detection and Printing.............................................................. 2-8

Quality Start........................................................................................ 2-9

2.4.2 PAPER DETECTION AND PRINTING PRESSURE ON/OFF

MECHANISM ............................................................................... 2-10

2.5 IMAGE PROCESSING........................................................................... 2-11

2.5.1 OVERVIEW................................................................................... 2-11

2.5.2 MASTER MAKING ........................................................................ 2-12

2.5.3 THERMAL HEAD PROTECTION .................................................. 2-12

2.6 PAPER MISFEED DETECTION............................................................. 2-13

3. INSTALLATION............................................................................ 3-1

3.1 INSTALLATION REQUIREMENTS.......................................................... 3-1

3.1.1 OPTIMUM ENVIRONMENTAL CONDITIONS................................. 3-1

3.1.2 ENVIRONMENTS TO AVOID.......................................................... 3-2

3.1.3 POWER CONNECTION.................................................................. 3-3

3.1.4 ACCESS TO THE MACHINE .......................................................... 3-4

3.2 ACCESSORY CHECK............................................................................. 3-5

3.3 INSTALLATION PROCEDURE................................................................ 3-6

4. SERVICE TABLES.......................................................................4-1

4.1 SERVICE REMARKS............................................................................... 4-1

4.2 SERVICE TABLES................................................................................... 4-2

4.2.1 MAINTENANCE TABLES................................................................ 4-2

Lubrication Points............................................................................... 4-2

User's Maintenance............................................................................ 4-5

Periodic Inspection (every 6 months).................................................. 4-5

Periodic Inspection (every 12 months)................................................ 4-6

4.2.2 SERVICE CALL CODES................................................................. 4-7

4.2.3 DIP SWITCHES, LEDS, VRS, TPS

(ON THE MAIN CONTROL PCB)................................................. 4-10

DIP Switches.................................................................................... 4-10

Photodiodes...................................................................................... 4-10

VRs................................................................................................... 4-11

TPs................................................................................................... 4-11

4.2.4 EXPECTED LIFE OF PARTS........................................................ 4-11

4.2.5 SPECIAL TOOLS.......................................................................... 4-12

4.3 SERVICE PROGRAM MODE................................................................. 4-13

4.3.1 SERVICE PROGRAM MODE OPERATION.................................. 4-13

Service Program Mode Access Procedure (for engineers)................ 4-13

Service Program Mode Access Procedure (for users) ...................... 4-14

Change Adjustment Values or Modes............................................... 4-14

4.3.2 SERVICE PROGRAM TABLE....................................................... 4-15

4.3.3 THERMAL HEAD TEST ................................................................ 4-32

4.3.4 COMMAND SHEET CHECK ......................................................... 4-33

4.3.5 INPUT/OUTPUT CHECK MODE................................................... 4-34

Input Check Mode Access Procedure............................................... 4-34

Output Check Mode Access Procedure............................................ 4-34

Input Check Table............................................................................. 4-35

4.3.6 USER CODE MODE...................................................................... 4-42

User Codes....................................................................................... 4-42

How To Use a User Code................................................................. 4-42

5. REPLACEMENT AND ADJUSTMENT ......................................... 5-1

5.1 MASTER FEED........................................................................................ 5-1

5.1.1 THERMAL HEAD VOLTAGE ADJUSTMENT.................................. 5-1

5.2 PAPER FEED .......................................................................................... 5-3

5.2.1 SECOND FEED ROLLER START TIMING...................................... 5-3

5.2.2 PAPER FEED ROLLER REMOVAL ................................................ 5-5

5.3 DELIVERY............................................................................................... 5-6

5.3.1 EXIT PAWL TIMING ADJUSTMENT............................................... 5-6

6. POINT TO POINT DIAGRAM (C228)............................................6-1

SECTION 1

OVERALL MACHINE

INFORMATION

29 January 1998 SPECIFICATIONS

1. OVERALL MACHINE INFORMATION

1.1 SPECIFICATIONS

Configuration: Table-top
Master Processing: Digital
Printing Process: Fully automatic one-drum stencil system
Original Type: Sheet/Book
Original Size: Maximum 307 mm x 432 mm (12.0" x

17.0")

Reduction Ratios: Inch version:

93%, 77%, 74%, 65%
Metric version:
93%, 87%, 82%, 71%

Enlargement Ratios: Inch version:

155%, 129%, 121%
Metric Version:

141%, 122%, 115%
Zoom: From 50% to 200% in 1% steps
Directional Magnification: Vertical: From 50% to 200% in 1% steps

Horizontal: From 50% to 200% in 1% steps

Overall

Information

Image Mode: Letter, Photo, Letter/Photo
Color Printing: Drum unit replacement system

(Red, Blue, Green, Brown, Yellow, Purple,

Navy, and Maroon)
Master Feed/Eject: Roll master, automatic feed/eject
Leading Edge Margin: 5 mm (0.2")
Trailing Edge Margin: 3 mm (0.12")
Print Paper Size: Maximum 297 mm x 432 mm

(11.6" x 17.0")

Minimum 90 mm x 148 mm (3.6" x 5.8")
Printing Area: A3 drum (original drum)

More than 290 mm x 412 mm

Optional A3 drum

More than 290 mm x 407 mm

Optional A4 drum

More than 290 mm x 204 mm

Print Paper Weight:

47.1 g/m

2

to 209.3 g/m2 (12.5 lb to 55.6 lb)

1-1

SPECIFICATIONS 29 January 1998

Printing Speed: 60, 75, 90, 105, 120 sheets/minute
First Copy Time

(Master Process Time):
Second Copy time

(First Print Time):
Paper Feed Table Capacity:

Paper Delivery Table

Less than 46.0 seconds (A3)

Less than 37.0 seconds (A4)

Less than 48.0 seconds (A3)

Less than 39.5 seconds (A4)

2

1,000 sheets (80 g/m

1,000 sheets (80 g/m

, 20 lb)

2

, 20 lb)

Capacity:
Power Source: 120 V, 50/60 Hz: 3.6 A (for N. America)

220/240 V, 50/60 Hz: 2.0 A (for Europe,

Asia)
Power Consumption: 120 V, 50/60 Hz: 360 W (for N. America)

220/240 V, 50/60 Hz: 350 W (for Europe,

Asia)
Weight: 120 V version: 127 kg

220/240 V version: 127 kg

Cabinet: 23.5 kg
Dimensions (W x D x H):

Width Depth Height

Stored 719 mm, 28.4" 698 mm, 27.5" 644 mm, 25.4"
Stored with document

feeder
Set up 719 mm, 28.4" 698 mm, 27.5" 644 mm, 25.4"
Set up with cabinet 719 mm, 28.4" 698 mm, 27.5" 1,070 mm, 42.2"
Set up with document

feeder
Set up with cabinet and

document feeder

719 mm, 28.4" 698 mm, 27.5" 666 mm, 26.3"

1,331 mm, 52.5" 698 mm, 27.5" 666 mm, 26.3"
1,331 mm, 52.5" 698 mm, 27.5" 1,092 mm, 43.0"

Original Scanning Time: 3.07 ms/line
Master Making Density: 600 dpi (CCD: 400 dpi)
Master Eject Box Capacity: More than 70 masters under low temperature

q

More than 100 masters at 23

C, 73qF and

over
Paper Separation: Friction roller/center separation system
Feed Table Side Plate

88 mm to 336 mm (3.46" to 13.2")
Movement:

Side Registration:

r

10 mm

Vertical Registration: More than +10 mm, -20 mm

1-2

29 January 1998 SPECIFICATIONS

Ink Supply: Automatic ink supply system
Paper Delivery: Air knife/vacuum delivery
Print Counter: 7 digits
Supplies: Master Thermal master 320 mm width

370 masters/roll (with A4 drum)
250 masters/roll (with A3 drum)
(VT-6 master)

Max. run length 2000 prints

Ink 1000 cc ink pack (black)

600 cc ink pack
(Red, Blue, Green, Brown,
Yellow, Purple, Navy, Maroon)

Overall

Information

1-3

MAJOR DIFFERENCES BETWEEN THE C223 AND THE C228 29 January 1998

1.2 MAJOR DIFFERENCES BETWEEN THE C223 AND
THE C228

No. Item Details

1 Thermal Head A new 600 dpi thermal head is used.
2 Thermal Head Pressure

Release Mechanism

3 Improvements for Better

Master Feeding in the
Master Feed Unit

4 Paper Feed Roller The core of the paper feed roller has been changed

5 Paper Separation Plate The shape of the separation plate has been

6 Paper Feed Cam and

Printing Pressure Cam

7 Paper Detection System

for Starting Applying the
Printing Pressure

8 Master Eject Roller Grooves have been made in the lower master feed

The thermal head is pressed against the platen
roller only during the master making process. A
unique dc motor is used for this mechanism. For
details, refer to ‘Master Feed’ in the Detailed
Section Descriptions section.

The new master is thinner and has a smoother
surface. Some improvements have been made to
improve master feed. For details, refer to ‘Master
Feed’ in the Detailed Section Descriptions section.

to improve paper feed. For details, refer to ‘Paper
Feed’ in the Detailed Section Descriptions section.

changed for better paper feeding. For details, refer
to ‘Paper Feed’ in the Detailed Section Descriptions
section.

For better printing quality, the shape of the printing
pressure cam (the cam profile) has been changed.
Also, the shapes of the two paper feed rollers have
been changed in order to make the paper
registration more accurate. For details, refer to
‘Paper Feed’ and ‘Printing’ in the Detailed Section
Descriptions section.

For better printing, the printing pressure application
timing has been changed. Because of the strictly
controlled timing, a photocoupler (the paper
registration sensor) is used to detect when to start
applying the printing pressure. (The paper detection
feeler used in the C223 has been removed.) For
details, refer to ‘Printing’ in the Detailed Section
Descriptions section.

rollers to improve master feed. For details, refer to
‘Master Eject’ in the Detailed Section Descriptions
section.

1-4

29 January 1998 MAJOR DIFFERENCES BETWEEN THE C223 AND THE C228

No. Item Details

9 Paper Delivery Table The C228 uses a new paper delivery table. (This

table is also used for the recent C223 because of a
modification.) This new table has small guide plates
[A] on the front and rear side fences. The guide
plates stack the prints more evenly. The small
guide plates [B], on the bottom of each side fence,
keep the prints aligned in the center of the table
while the prints are being stacked.

[A]

[B]

C228V500.WMF

Due to the new paper delivery table design, the set
position of the optional tape marker is different from
that for the C223. Use the screw holes [C] shown
below.

Overall

Information

[C]

C532I504.PCX

10 Thermal Head Drive The voltage to the thermal heating elements in the

thermal head is different from that of the C223. The
DC/DC Converter Board which is newly added
supplies the voltage while using the same power
supply board as the C223.

Also, the thermal head drive board used in the
C223 has been removed. The function has been
built into the image processing board.

11 Image Shifting Mode The shift range in the backward direction in image

shifting mode has been changed from 15 mm to 10
mm. This is due to the changed printing pressure
application timing. (In the forward direction, it is 20
mm as before.)

12 Make-up Function The memory chips for the Make-up function, which

was an option for the C223, are built into the image
processing board.

1-5

MAJOR DIFFERENCES BETWEEN THE C223 AND THE C228 29 January 1998

No. Item Details

13 New Replacement and

Adjustment Procedures

x

The thermal head voltage adjustment
procedure has been changed.

x

The adjustment standard for the second
feed roller start timing has been changed
from 177q to 144q.

x

A remark has been added to the paper
feed roller removal procedure.

x

The adjustment standard for the exit pawl
timing has been changed from 230 r 2q to
228 r 2q.

For details, refer to the Replacement and
Adjustment section.

14 New Master A new more heat-sensitive master is used to

improve the printing quality.

Due to the new master material, the capacity of the
master eject box has been increased.

Because the new master surface is slippery, the
new master roll is tightened with tape [A] as shown
below to prevent the roll from becoming loose. The
master roll installation method has been changed.
(For details, refer to ‘Installation Procedure’ in the
Installation section.)

[A]

C228V502.WMF

1-6

29 January 1998 MAJOR DIFFERENCES BETWEEN THE C223 AND THE C228

No. Item Details

15 New SP Modes The default setting for the thermal head energy for

the economy mode (SP35-2) has been changed
from -35% to -30%. (In other words, the energy
used in economy mode has been increased.)

The following SP modes are new for the C228:
SP51: Clear Multi Copy
SP52: Compress W Start Key
SP78-1: Letter/Pht Mode [CS]
SP78-2: Clear/Original

SP51 and SP78 are accessible to users. SP78

Note:

also can be registered in CS mode.

- Functions -

SP51: Resets the Combine 2 Originals or
Combined Print function (if it has been set) after the
master making process. There are two options: 0:
No, 1: Yes. “0” is the default.

Overall

Information

16 New Input/Output Check

Mode

SP52: The masters in the master eject box can be
compressed every time the Master Making key is
pressed. There are two options: 0: No, 1: Yes. “0”
is the default.

If this mode is enabled, it reduces the

Note:

possibility of the master eject belts slipping off, which
tends to occur when the master box is full.

SP78-1: Select whether the reproduction of letter
mode areas is emphasized when Letter/Photo
mode is used. There are two options: 0: Standard,
1: Emphasized. “0” is the default.

SP78-2: Select whether the image mode (letter,
photo, or letter/photo) is to be returned to the
default setting when master making is finished.
There are two options: 0: No, 1: Yes. “0” is the
default.

The following are the new items for the Input/Output
Check Mode:

Input: 51 SN: Paper Registration

(Paper Registration Sensor)

Input: 52 SN: T. Head Position

(Thermal Head Pressure Release
Sensor)

Output: 42 MOTOR: T. Head Up/Down (Turns
on

the thermal head pressure release
motor.)

1-7

SECTION 2

DETAILED SECTION

DESCRIPTIONS

29 January 1998 MASTER EJECT

2. DETAILED SECTION DESCRIPTIONS

2.1 MASTER EJECT

Grooves have been added on the lower master eject rollers for better master
feeding.



CAUTION

The lower master eject roller must be installed the correct way around. The
groove [A] on the shaft (see the illustration) must be on the operation side.

Detailed

Descriptions

[A]

C228D501.WMF

2-1

MASTER FEED 29 January 1998

2.2 MASTER FEED

2.2.1 MASTER FEED MECHANISMS

A 600 dpi thermal head and a new more heat-sensitive master is used to improve
the printing quality. The new master is thinner and has a smoother surface. The
following improvements are implemented to improve master feed.

1. Three master buffer fan motors [A] are used instead of the one fan motor used

in the C223. This generates stronger suction to guide the master into the
master box [B].

[B]

[A]

[D]

[E]

[C]

C228D502.WMF

2. To ensure correct master feed, the material of the upper master feed roller [C]

has been changed to an anti-static rubber. (A sponge-like material was used
for the C223.)

The new master feed roller [C] rotates slightly faster than the platen roller [D].
This stretches the master on the thermal head (under the platen roller) and
makes sure that the master is made accurately. A torque limiter built into the
upper master feed roller gear can release the master feed force to prevent the
master from being damaged in this area.

Also, the counter roller [E] has been added to prevent the master from
wrapping around the upper master feed roller.

2-2

29 January 1998 MASTER FEED

[B] [C]

[A]

[D]

C228D503.WMF

3. A metal master guide plate was used between the master feed roller and

reverse roller for the C223. This was good for grounding static electricity.
However, when static electricity is grounded, the master tends to stick to the
guide plate. As a thinner master is used for the C228, the guide plate [A] is
made of a plastic material. This prevents the master from being stuck on the
guide plate surface even if static electricity is generated. Also, ribs have been
added to the new guide plate to feed the master more smoothly.

4. Four strips of mylar [B] have been added to the surface of the master guide

plates. This can prevent the master from catching on the rollers under the
master feed and reverse rollers. Other strips of mylar are used in front of the
master feed roller [C] and after the platen roller [D].

NOTE:

These mylar strips must be carefully repositioned when the rollers are
reinstalled.

Detailed

Descriptions

2-3

MASTER FEED 29 January 1998

2.2.2 THERMAL HEAD PRESSURE RELEASE MECHANISM

[B]

[B]

[B]

[A]

[A]

[C]

[C]

[A]

[C]

[D]

[F]

[E]

C228D504.WMF

The thermal head [A] is pressed against the platen roller [B] only during the master
making process. The thermal head position is moved up and down by changing
the position of the cam [C].

The cam position is changed by the thermal head pressure release motor [D] via
gears. The thermal head pressure release sensor [E] monitors the cam position.
The sensor, which is a photointerrupter, is interrupted by the shutter mounted on
the gear [F] as the pressure release motor turns to maintain the cam position.

2-4

29 January 1998 PAPER FEED

2.3 PAPER FEED

To improve paper feed, especially for thin paper, the paper feed roller and the
separation plate have been changed.

In addition, the shapes of the two paper feed cams (the cam profiles) have been
changed in order to make the paper registration more accurate.

With the new cams, the leading edge of the paper reaches the second feed roller
faster than before. Then, the second feed roller can start feeding the paper earlier.

Thanks to this, the second feed roller can start feeding the paper at a lower
transportation speed. (The time that the paper reaches the press roller position is
still the same, but the acceleration from the second feed roller has become more
moderate.) As a result, the paper registration has become more accurate.

Since the timing for the second feed roller to start feeding the paper was
advanced, the paper detection feeler used in the C223 could not be used. A
photocoupler is used instead. For more details about this, refer to the Printing
section.

NOTE:

1) Due to the new cams, the adjustment values for second feed roller
operation are changed. For details, refer to ‘Feed Length of the Second
Feed Roller Adjustment‘ and ‘Second Feed Roller Start Timing
Adjustment‘ in the ‘Replacement and Adjustment’ section. (The ‘Feed
Length of the Paper Feed Roller Adjustment’ procedure is still the
same.)

2) The new paper feed cams cannot be used on the older models since
those models use the paper detection feeler.

Detailed

Descriptions

2-5

PAPER FEED 29 January 1998

2.3.1 PAPER FEED ROLLER

[B]

35.5

a

36.5 mm

[C]

C228D505.WMF

[A]

In this model, the two rubber rollers [A] on the core roller are separated. This helps
to prevent creasing of paper that can be caused by the narrower roller assembly of
the C223. (This was likely with very thin paper.)

The material of the core roller [B] was changed from plastic to metal for better
stiffness. As a result, to balance the weight of the whole paper feed roller unit, the
number of balancing weight plates on the feed roller bracket was reduced from
three to two.

Since the weight of the paper feed roller itself has increased, the roller tends to
overrun (it keeps on feeding paper) after the roller driving force stops. To prevent
this, a spring [C] which works as a brake has been added at the end of the shaft.

NOTE:

When servicing, make sure that the core roller is between 35.5 mm and

36.5 mm from the end of the shaft.

2-6

29 January 1998 PAPER FEED

2.3.2 PAPER SEPARATION PLATE

[D]

[C]

[A]

[B]

C228D506.WMF

If the leading edge of paper stacked on the paper table curls downwards, it tends
to be caught by the separation plate and this causes a jam. The shape of the
separation plate [A] has been changed (see the diagram) to improve paper feed in
such a case.

For the same purpose, the shape of the upper edge of the entrance plate [B]
(which holds the separation plate) has been changed as shown.

The rubber part of the separation plate [C] has been lengthened to improve paper
feed, especially for thick paper. The lengthened rubber can guide the paper
leading edge to the upper separation roller [D] surface more precisely. Because of
this, the paper edge hits the upper separation roller more gently. This prevents the
paper leading edge from being damaged at the area where the separation plate
(the rubber part) contacts the upper separation roller surface. (This was likely with
thick paper.)

Detailed

Descriptions

2-7

PRINTING 29 January 1998

2.4 PRINTING

2.4.1 OVERVIEW

Printing Pressure Cam

For better printing quality, the shape of the printing pressure cam (the cam profile)
has been changed.

The new cam applies printing pressure to the drum faster than before. The press
roller is pressed against the ink roller (the master and the drum screens are in
between) before the leading edge of the paper reaches this section.

In the C223, the press roller is pressed against the ink roller just when the paper
leading edge reaches this point. In this case, the paper leading edge is strongly
pressed against the master surface on the drum. Since the new master is thinner
and delicate, the paper leading edge tends to damage the master surface if the
same printing pressure cam is used, especially during a long printing run. (If the
master surface is damaged, ink will leak and transfer onto the paper.) The new
printing pressure cam can avoid this situation.

NOTE:

1) Because of the new printing pressure cam, the adjustment values
(angles) for printing pressure application timing and exit pawl operation
timing are changed. Refer to ‘Pressure Timing Adjustment’ and ‘Exit
Pawl Timing Adjustment’ in the ‘Replacement and Adjustment’ section.

2) The new printing pressure cam cannot be used in the older models.
Because of the new cam profile, the shift range in the backward
direction in image shifting mode has been changed from 15 mm to 10
mm. (In the forward direction, it is 20 mm as before.)

Paper Detection and Printing

In the C223, the paper detection feeler was used in order to prevent the press
roller from contacting the drum (without paper) and getting ink on it when a paper
misfeed occurred before the paper reached the press roller.

The paper detection feeler could be pressed downwards by paper since a gap
between the paper detection arm and the pressure on/off lever was created when
the widest part of the pressure cam reached the bearing on the pressure on/off
lever. With the earlier second feed roller start timing, this gap cannot be created.
Therefore, the same mechanism is not used. (The timing was changed to make
paper registration more accurate; see the Paper Feed section for details.)

NOTE:

Instead of the paper detection feeler, the registration sensor (a photocoupler) is
used. When the sensor detects the paper, the printing pressure solenoid energizes
to start applying the printing pressure. (In the C223, the printing pressure solenoid
was energized as soon as paper feed started.) The sensor is also used as a paper
jam detector.

For the details of the paper detection feeler operation, refer to the C223
Service Manual. (Section 5.2, ‘Paper Detection And Printing Pressure
On/Off Mechanism’ in the ‘Detailed Section Descriptions’ section.)

2-8

29 January 1998 PRINTING

For more details about this mechanism, refer to the following ‘Paper Detection and
Printing Pressure On/Off Mechanism’ section.

Quality Start

The detection arm release solenoid which was used in the C223 has been
removed. Since the paper detection feeler has been removed, the detection arm
release solenoid is not necessary to start the drum stroke operation in the quality
start mode.

When the drum stroke operation starts, the printing pressure solenoid turns on.
This disengages the pressure on/off lever and starts applying the printing
pressure.

Detailed

Descriptions

NOTE:

For the details of the quality start mode operation, refer to the C223
Service Manual. (Section 5.4 ‘Quality Start Operation’ in the ‘Detailed
Section Descriptions’ section.)

2-9

PRINTING 29 January 1998

2.4.2 PAPER DETECTION AND PRINTING PRESSURE ON/OFF
MECHANISM

[A]

[B]

[C]

[D]

[E]

[G]

[F]

C228D507.WMF

When the paper is detected by the paper registration sensor [A], the printing
pressure solenoid [B] is energized. The stopper arm [C] then disengages the
pressure on/off lever [D]. The pressure on/off lever, which is connected to the end
of the press roller arm [E], starts moving when the printing pressure cam [F] starts
moving; the cam moves bearing [G], which is on the lever. The press roller is
pressed against the ink roller.

The printing pressure solenoid is de-energized when the printing pressure sensor
is activated; this is soon after it is energized. The stopper arm [C] returns and is
pressed against the pressure on/off lever, due to tension from a spring. (The
stopper arm just rides on the edge of the pressure on/off lever at this time.) To
finish applying the printing pressure, the bearing [G] on the pressure on/off lever is
pushed by the printing pressure cam and the lever turns clockwise, until it is
engaged by the stopper arm.

If the next sheet of paper is detected by the registration sensor within a certain
period, the printing pressure solenoid is again energized to disengage the pressure
on/off lever. The printing pressure for the next sheet of paper starts being applied.

If the registration sensor is not activated, the machine detects a paper misfeed
condition (Location B Misfeed). In this case, the printing pressure solenoid stays
de-energized and the printing pressure is not applied. This can prevent the press
roller contacting the drum (without paper) and getting ink on it because of the
paper misfeed.

NOTE:

In the C223, Location B Misfeed was detected when the printing pressure
sensor was not activated within a certain period.

2-10

29 January 1998 IMAGE PROCESSING

2.5 IMAGE PROCESSING

2.5.1 OVERVIEW

Analog signal

CCD PCB

Thermal Head

1-bit

A/D Conversion

PCB

6-bit

Image

Processing PCB

Main Control

PCB

Image Settings

Operation Panel

C228D508.WMF

Detailed

Descriptions

The light reflected from the original goes to the CCD, which converts the light
signal into an analog electrical signal. The analog signal is sent to the A/D
conversion PCB, where it is changed to 6-bit digital data. The 6-bit data is changed
to 1-bit data in the image processing PCB and it goes to the thermal head. The
thermal head drive circuit is built into the image processing PCB.

The 6-bit to 1-bit conversion procedure depends on the image settings on the
operation panel.

2-11

IMAGE PROCESSING 29 January 1998

2.5.2 MASTER MAKING

The operation of the thermal head is just like that of the C223, except that the
thermal head drive circuit has been built into the image processing board.

The new 600 dpi thermal head is used with the new more heat-sensitive master.
The specifications of the thermal head are as follows:

z

Density of Thermal Heating Elements: 600 dpi

z

Number of Thermal Heating Elements: 7168 dots

z

Maximum Master Making Width: 303.45 mm

2.5.3 THERMAL HEAD PROTECTION

Pulse Generator
Circuit

A/D

Conversion

Circuit

Main Control PCB

CN111-A8 CN404-A8

CN111-A1 CN404-A1

/ P:CLK

/ P:LSYNC
/ P:DATA
/ ENLPLS

Thermal Head Drive Circuit

Gate Array

Image Processing PCB

DI1~4

Thermal Head

CK1~4

LAT1~4

STB1~4

Thermistor

C228D509.WMF

DC/DC

Converter

PCB

The thermistor on the thermal heat prevents it from overheating when continuously
processing a solid image.

The CPU checks for abnormal conditions when the Master Making key is pressed,
and indicates an SC code on the operation panel under the following conditions:

SC Code Conditions

E-04 The thermistor on the thermal head detected a temperature of over

54qC. (CN111-A1 is below 1.17 volts.)

E-09 The thermistor is open, or related connectors are not connected.

(The signal level between CN111-A1 and GND is over 4.9 volts.)

2-12

29 January 1998 PAPER MISFEED DETECTION

2.6 PAPER MISFEED DETECTION

175°

1st Drum Position Sensor

2nd Drum Position Sensor

Paper Registration Sensor

Printing Pressure Sensor

2nd Paper Exit Sensor

Printing Pressure Solenoid

175°

175°

C228D510.WMF

[a] When the drum has rotated 175q after activating the 1st drum position sensor,

if the paper registration sensor is still OFF, a paper misfeed (Location B jam) is
detected.

[b] When the 2nd drum position sensor turns on, if the 2nd paper exit sensor

remains ON, a paper misfeed (Location G jam) is detected.

Detailed

Descriptions

20° 25° 25° 20°

1st Drum Position Sensor

2nd Drum Position Sensor

Paper Registration Sensor

Printing Pressure Sensor

1st Paper Exit Sensor

2nd Paper Exit Sensor

20°

BE Jam

E Jam

C228D511.WMF

[c] When the drum has rotated 20q after activating the 2nd drum position sensor, if

the 1st paper exit sensor is still OFF, a paper misfeed (Location BE jam) is
detected.

[d] When the drum has rotated 25q after activating the 1st drum position sensor, if

the 2nd paper exit sensor is still OFF, a paper misfeed (Location E jam) is
detected.

2-13

SECTION 3

INSTALLATION PROCEDURE

29 January 1998 INSTALLATION REQUIREMENTS

3. INSTALLATION

3.1 INSTALLATION REQUIREMENTS

3.1.1 OPTIMUM ENVIRONMENTAL CONDITIONS

Installation

Temperature

Humidity





C223I518.PCX

10 to 30qC
(50 to 86qF)

20 to 90 % RH The machine must be level within

On a strong and level base.

5 mm (13/64") both front to rear
and left to right.

C223I519.PCX

3-1

INSTALLATION REQUIREMENTS 29 January 1998

3.1.2 ENVIRONMENTS TO AVOID

Locations exposed to direct

C223I520.PCX

Dusty areas.

C223I521.PCX

sunlight or strong light (more than
1,500 lux).

C223I523.PCX

C223I525.PCX

Areas with corrosive gases. Locations directly exposed to cool air

from an air conditioner or reflected
heat from a space heater. (Sudden
temperature changes from low to
high or vice versa may cause
condensation within the machine.)

3-2

29 January 1998 INSTALLATION REQUIREMENTS

3.1.3 POWER CONNECTION

C223I524.PCX

Securely connect the power cord
to a power source.

Make sure that the wall outlet is
near the machine and easily
accessible.

Make sure the plug is firmly
inserted in the outlet.

C223I516.PCX

Voltage must not fluctuate more than
10%.

Installation

C223I515.PCX

C223I517.PCX

Avoid multiwiring. Do not pinch the power cord.

3-3