Ricoh VT2100 S Service Manual vt2100

RICOH PRIPORT VT 2000 SERIES

(VT2100/2130/2150/2300/2500)

SERVICE MANUAL

SECTION 1

OVERALL MACHINE

INFORMATION

28 February ’91

1. SPECIFICATIONS

VT2300/VT2500

Configuration: Desktop
Master processing: Digital
Printing process: Full automatic one drum stencil system
Original type: Sheet
Original size: Maximum 307 mm x 432 mm (12.0" x 17.0")

Minimum 90 mm x 140 mm (3.6" x 5.5")

Reproduction ratios: 3 Enlargement and 3 Reduction

LT Version A4 Version

Enlargement 141% 141%

127% 122%

115% 115%
Full Size 100% 100%
Reduction 93% 93%

75% 82%

64% 71%

Image mode: Line/Photo
Color Printing: Drum Unit replacement system
Master feed/eject: Roll master automatic feed/eject
Printing area: Maximum: 250 mm x 350 mm (9.8" x 13.7") at

20°C/ 65 % RH.

Leading edge margin:

± 3 mm at "0" position

10

Print paper size: Minimum: 90 mm x 148 mm (3.6" x 5.8")

Maximum: 325 mm x 447 mm (12.8" x 17.6")

Print paper weight: 50 g/m

2

to 215 g/m

2

Printing speed: 60, 75, 90, 105, 120 sheets/minute (5 steps)

1-1

28 February ’91

First print time: 34.5 seconds (B4 size)

31.5 seconds (A4 Size)

2

Paper feed table

1000 sheets (66.3 g/m

/17.6 lb)

capacity:

2

Paper delivery table

500 sheets (66.3 g/m

/ 17.6 lb)

capacity:

Power source: 110V, 60 Hz.....................6.0A

120 V, 60 Hz....................5.5 A

220/240 V, 50/60 Hz........2.7 A

Power consumption: 110/120 V version: 430 W

220/240 V version: 470 W

Weight: 120 V version: 102 kg (224.8 lb)

220/240 V version: 107 kg (235.8 lb)
Optional Table: 26 kg (57.3 lb)

Dimensions:
(W x D x H)

Stored: 735 mm x 607 mm x 577 mm
(29.0" x 23.9" x 22.8")
Set up: 1279 mm x 607 mm x 656 mm
(50.4" x 23.9" x 25.9")
Table: 640 mm x 570 mm x 455 mm
(25.2" x 22.4" x 17.9")

2

ADF original capacity: 20 sheets (66 g/m
Original guide width

98 mm to 316 mm (38.6" to 12.44")

) or 1.8 mm height

settings:
Original scanning time: 3 ms/1 line
Original thickness: 0.05 mm to 0.8 mm
Original feed speed: 20.8 mm/second (When master processing)

41.7 mm/second (When not master processing)
Pixel density: 16 dots/mm
Master eject box

capacity:

25 masters (Normal condition)
20 masters (10°C/30% RH Condition)

Paper feeding: Friction roller/center separation system

1-2

28 February ’91

Feed table side plate

88 mm to 330 mm (3.46" to 12.99")

width settings:
Paper feed roller

pressure:
Separation roller

pressure:
Side registration:
Vertical registration:

Normal position................250 g

Thick paper position.........550 g

Normal position................180 g

Weak position ..................70 g

± 10 mm (manual)
± 20 mm (mechanical)

Ink Supply: Automatic ink supply system
Press roller pressure:

± 0.3 kg

10
Paper Delivery: Air knife/vacuum delivery
Delivery side plate width

80 mm to 320 mm (3.15" to 12.6")
settings:

Print counter: 7 digits
Master counter: 6 digits
Supplies:

Priport Thermal master 280 mm width
Master VT-M:
(16 dots/mm)

Master roll 250 masters/1 roll

Roll diameter 130 mm

Master length 480 mm/1 master

Max run length 2000 prints

Ink Colors: Black, Red, Blue, Green, Brown
(500 cc/pack)

1-3

28 February ’91

VT2100 Series (VT2100, VT2130, VT2150)

Configuration: Desk top
Master processing: Digital
Printing process: Full automatic one drum stencil system
Original type: Sheet
Original size: Maximum 307 mm x 432 mm (12.0" x 17.0")
Reproduction ratios: LT version: 100 %, 93 %, 75 %, 64 %

A4 version: 100 %, 93 %, 82 %, 71 %
Image mode: Line/Photo
Color printing: Drum unit replacement system
Master feed/eject: Roll master automatic feed/eject
Master processing area: VT2100: Maximum 256 mm x 354 mm

(10.1" x 13.9")

VT2130: Maximum 216 mm x 354 mm

(8.5" x 13.9")

VT2150: Maximum 216 mm x 287 mm

(8.5" x 11.3")
Printing area: VT2100: Maximum 250 mm x 350 mm

(9.8" x 13.7") at 20°C/65 % RH

VT2130: Maximum 210 mm x 350 mm

(8.3" x 13.7") at 20°C/65% RH

VT2150: Maximum 210 mm x 283 mm

(8.3" x 11.1") at 20°C/65% RH
Leading edge margin: 10 mm
Print paper size: Minimum 90 mm x 148 mm (3.6" x 5.8")

Maximum 297 mm x 442 mm (11.6" X 17.4")
Print paper weight: 50 g/m

2

to 215 g/m

2

Print speed: 60, 75, 90, 105, 120 sheets/minute (5 steps)
First print time: VT2100: 35 seconds (B4 size)

VT2130: 35 seconds (LG size)

VT2150: 31 Seconds (A4 size)

1-4

Paper feed table capacity 1000 sheets (66.3 g/m2 / 17.6 lb)

2

Paper delivery table

500 sheets (66.3 g/m

/ 17.6 lb)

capacity:

Power source: 220/240V, 50/60 Hz.........2.7A

120V, 60 Hz.....................5.5 A

110V, 60 Hz.....................6.0 A

Power consumption: 110/120 V version: 430 W

220/240 V version: 470 W
Weight: 110/120 V version: 100 kg (220.4 lb)

220/240 V version 105 kg (233.7 lb)

Optional table: 26 kg (57.3 lb)

28 February ’91

Dimensions:
(W x D x H)

When stored: 735 mm x 607 mm x 569 mm

(29.0" x 23.9" x 22.4")

When set up: 1279 mm x 607 mm x 656 mm

(50.4" x 23.9" x 25.9")

Table only: 640 mm x 570 mm x 455 mm

(25.2" x 22.4 x 17.9")
Original guide

98 mm to 316 mm (38.6" to 12.44")
width-settings:

Original scanning time: 3 ms/1 line
Original thickness: 0.06 mm to 0.5 mm
Original feed speed: 20.8 mm/second
Pixel density: 16 dots/mm
Master eject box

capacity:

25 masters (at normal conditions)

20 masters (at 10°C/30 % RH)
Paper feeding: Friction roller/center separation system
Feed table side plate

width settings:
Paper feed roller

pressure:
Separation roller

pressure:

88 mm to 317 mm (3.46" to 12.48")

Normal position ...............250 g

Thick paper position.........550 g

Normal position................180 g

Weak position ..................70 g

1-5

28 February ’91

Side registration:
Vertical registration:
Paper table raising /

lowering speed:

±10 mm (manual)

±20 mm (mechanical)

22 mm/second (50 Hz)

26 mm/second (60 Hz)
Ink supply: Automatic ink supply system
Pressure roller pressure:

± 0.3 kg

10
Paper delivery: Air knife/vacuum delivery
Delivery side plate

80 mm to 320 mm (3.15" to 12.6")
width settings:

Print counter: 7 digits
Master counter: 6 digits
Supplies:

Priport Master VT-M for VT2100:
(16 dots/mm) Thermal master 280 mm width

Master roll 250 masters/1 roll

Master length 480 mm/1 master

Max run length 2000 prints

Priport Master VT-S for VT2130/VT2150:

Thermal master 240 mm width

Max run length 2000 prints

VT2130: Master roll 250 masters/1 roll

Master length 480 mm/1 master

VT2150: Master roll 300 masters/1 roll

Master length 413 mm/1 master

Ink: 500 cc ink pack
Colors: Black, Red, Blue, Green, Brown

1-6

---- MEMO ----

28 February ’91

1-7

28 February ’91

2. GUIDE TO COMPONENTS AND THEIR
FUNCTIONS

(Paper Feed Side)

15

14

13

12

11

1 2 3

4

5

6

7

8

9

1-8

10

No. Name Function

28 February ’91

1. ADF Unit

(VT2300/2500)

2. ADF Unit Open

Feeds the original to the printing position
automatically.

Use to open the ADF unit.
Button
(VT2300/2500)

3. Original Guides Adjust these guides to position the originals
correctly.

4. Original Table Place the originals on this table.

5. Original Table

Release Lever

6. Feed Roller

Pressure Lever

7. Separation Roller

Pressure Lever

8. Paper Feed Side

Use to open the original table unit to the left for
master installation.
Use to adjust the contact pressure of the paper
feed roller according to paper thickness.
Use to adjust the separation roller pressure to
prevent double feed.
Use to prevent paper skew.

Plate

9. Paper Feed Table Set the paper on this table.

10. Side Plate Fine

Use to shift the paper feed table sideways.

Adjusting Dial

11. Front Door Open for access to the inside of the machine.

12. Paper Delivery Table Completed prints are delivered here.

13. Operation Panel Operator controls and indicators are located here.

14. ADF On/Off Select

Switch

When setting originals one sheet at a time, set this
switch to the Off position.

(VT2300/2500)

15. Original Tray Originals used to make a master are delivered to
this tray.

1-9

28 February ’91

(Paper Delivery Side)

25

24

23

26

27

28

16 17 18

19

22

20

21

1-10

28 February ’91

No. Name Function

16. Master Cut Button Press this button to cut the master paper leading
edge after installing a new master roll.

17. Pressure Release

Lever

18. Drum Rotating

Button

Use to install the master roll, or to clean the
thermal head.
Press to replace the drum or to remove misfed
paper.

19. Drum Unit The master paper is wrapped around this unit.

20. Ink Holder Set the ink cartridge in this holder.

21. Main Switch Use to turn the power on or off.

22. Small Size Paper

Delivery End Plate

Use to align the leading edge of small-sized (less
than A4/LT) prints.

(for smaller than
A4/LT)

23. Paper Delivery End

Plate (for larger

Use to align the leading edge of prints larger than
A4/LT.

than A4/LT)

24. Paper Delivery

Use to align the prints on the paper delivery table.

Side Plate

25. Master Eject

Open when removing the master eject container.

Container Cover

26. Memory/Class switch

Use to select memory or class mode.

(VT2300/2500)

27. Skip Paper Feed

Switch (VT2300/2500)
Printing Density
Select Switch

Use to adjust paper feed interval or a misted
master.
Use to select the printing density according to the
type and quality of the original.

(VT2100/2130/2150)

28. Master Eject Unit

Press to remove misfed paper or a misfed master.

Open Button

1-11

28 February ’91

3. OPERATION PANEL

VT2300/VT2500

1

20

1. Reset Key Press to reset error indicators.

2. Make-up Key Press to use the make-up function (VT2500 only).

3. Number Keys Press to enter the number of prints.

4. Stop Key Press to stop the machine operation. The machine

5. Clear Modes Key Press to cancel all previously entered settings and

6. Master Making
Key

7. Print Start Key Press to start printing.

8. Proof Key Press to make trial prints or extra prints.

9. Clear Key Press to change the number set in the counter.

10. Memory/Class Key Use to select group printing in Memory mode or

11. Lower Paper Feed
Table Key

12. Image Position
Keys

2

16

19 18

will continue operation when the Print Start key or
Master Making key is pressed.

modes.
Press to make a master.

Also use to change the make-up mode (VT2500
only). This key can be used only after the machine
stops operation.

Class mode.
Press to lower the paper feed table.

Press to shift the image forwards or backwards on
the print paper.

15

1417

1-12

28 February ’91

3

111213

910

4

5

8 7 6

13. Speed Keys Press to adjust the rotation speed of the machine
according to the type of image and printing paper.

14. Auto Cycle Key Use to automatically process masters and make
prints.

15. Full Size Key Press to make prints the same size as the original.

16. Reduce/Enlarge

Press to reduce or enlarge the image.

Key

17. Printing Density

Press to make prints darker or lighter.

Key

18. Image Mode Key Press to select line mode or photo mode according

to the type and quality of the original.

19. Combine 2

Originals Key

Press to combine two originals onto one print
image.

20. Monitors Light or blink when a non-standard condition
occurs within the machine.

1-13

28 February ’91

VT2100/VT2130/VT2150

1 2 3 4

18 17

16

1. Reset Key Press to reset error indicators.

2. Indicators Light or blink when a non-standard condition

occurs within the machine.

3. Auto Cycle Key Use to automatically process masters and make
prints.

4. Reduction Key Press to reduce the image.

5. Image Position

Keys

Press to shift the image forwards or backwards on
the print paper.

6. Number Keys Press to enter the number of prints.

7. Counter Displays the number of prints entered. While

printing, it shows the number of uncompleted
prints.

8. Memory Display Displays the number of the memory location that
will be used to store the number of copies. The
print number for up to 10 jobs can be stored at
once.

9. Print Start Key Press to start printing.

10. Master Making

Press to make a master.

Key

11. Proof Key Press to make trial prints or extra prints.

12. Stop Key Press to stop the machine operation. The machine

will continue operation when the Print Start key or
Master Making key is pressed.

1-14

28 February ’91

5 6

15

14 13 12

7 8

1110

9

13. Memory Key Use to select memory location number.

14. Clear Key Press to change the number set in the counter.

This key can be used only after the machine stops
operation.

15. Speed Keys Press to adjust the rotation speed of the machine
according to the type of image and printing paper.

16. Image Mode Key Press to select line mode or photo mode according
to the type and quality of the original.

17. Combine 2

Originals Key

18. Lower Paper Feed

Press to combine two originals onto one print
image.
Press to lower the paper feed table.

Table Key

1-15

28 February ’91

4. PRINTING PROCESS

2

1

6

4

5

1. Master Ejecting: Eject the used master wrapped around the drum
into the master eject box.

2. Scanning: Scan the original image by CCD through the mirror
and the lens while feeding the original.

3. Master Feeding: Convert the image signal read by CCD into the
digital signal and send it to the thermal head to
make holes on the surface of the master and then,
set the master around the drum.

4. Paper Feeding: Send paper to the drum section by using center
separation system consisting of the separation
plate and separation roller.

5. Printing: Press the paper fed from the paper feed section to
the drum to transfer the ink through drum screen
and the master.

6. Paper Delivering: Peel the printed paper with the Exit Pawl and Air
knife and eject the paper onto the paper delivery
table.

3

1-16

5. ELECTRICAL COMPONENT LAYOUT

28 February ’91

25

24

23

1

22

21

5

3

2

20

4

19

18

6

17

7

8

9

10
11

12

13

14

16

15

1. Original Registration Sensor

2. 2nd Original Sensor

3. Original Pressure Solenoid
(VT2300/VT2500)

4. Original Transport Motor

5. Fluorescent Lamp Stabilizer

6. Right Cutter Switch

7. Power Supply PCB

8. Thermal Head Drive Control PCB

9.Thermal Head

10. Master End Sensor

11. Master Feed Motor

12. Paper Size Detection Sensor 3
(VT2300/VT2500)

13. Paper Size Detection Sensor 2
(VT2300/VT2500)

14. Paper Size Detection Sensor 1
(VT2300/VT2500)

15. Paper Size Detection Board
(VT2300/VT2500)

16. Cutter Motor

17. Left Cutter Switch

18. Master Buckle Sensor

19. Master Eject Motor

20. Master Eject Solenoid

21. Master Box Switch

22. Master Eject Sensor

23. ADF Drive Motor (VT2300/VT2500)

24. 1st Original Sensor
(VT2300/VT2500)

25. Fluorescent Lamp

1-17

28 February ’91

27

26

28

29

30

31

32

33

34

42

41

35

36

40

37

39

26. Master Eject Clamper Solenoid

27. Ink Detection PCB

28. Master Feed Clamper Solenoid

29. Master Eject Unit Safety Switch

30. Image Shift Motor

31. Reverse Roller Solenoid

32. Encoder

33. 1st Drum Position Sensor

34. 2nd Drum Position Sensor

38

35. Paper Feed Solenoid

36. Paper Table Drive Motor

37. Drum Rotation Sensor

38. Main Motor

39. Printing Pressure Solenoid

40. AC Drive PCB

41. 1st Paper Exit Sensor

42. 2nd Paper Exit Sensor

1-18

28 February ’91

71

70

69

68

72

67

66

43

65

64

44

63

62

45

61

46

47

48

49

50
51
52
53
54
55
56

57
58

5960

43. CCD PCB

44. A/D Conversion PCB

45. Master Cutter Switch

46. Scanner Safety Switch

47. Drum Master Detection Sensor
(VT2300/VT2500)

48. Operation Panel

49. Drum Rotation Switch

50. Front Door Safety Switch

51. Drum Safety Switch

52. Ink Supply Solenoid

53. Main Control Board

54. Paper Table Height Sensor

55. Image Processing PCB

56. Drum Lock Solenoid

57. Paper End Sensor

58. Paper Table Safety Switch

59. Paper Table Lower Limit Sensor

60. Printing Pressure Sensor

61. Copy Counter

62. Master Counter

63. Interlock Switch

64. Circuit Breaker

65. Main Switch

66. Air Knife Motor

67. Vacuum Motor

68. Full Master Detecting Switch

69. Pressure Plate Position Switch

70. Memory/Class Switch
(VT2300/VT2500)

71. Skip Paper Feed Switch
(VT2300/VT2500)
Printing Density Switch
(VT2100 /VT2130/VT2150)

72. A.D.F. Safety Switch
(VT2300/VT2500)

1-19

28 February ’91

6. ELECTRICAL COMPONENT DESCRIPTIONS

INDEX

No.

Motors

4 Original Transport Motor Transports the original to the scanner

11 Master Feed Motor Feeds the master to the drum. E-3
16 Cutter Motor Cut the master. F-6
19 Master Eject Motor Sends used master into the master

23 ADF Drive Motor Feeds the original to the scanner

30 Image shift Motor Changes the timing between the paper

36 Paper Table Drive Motor Raises and lowers the paper table. F-5
38 Main Motor Drives paper feed, drum, printing and

66 Air Knife Motor Rotates the fan to separate the paper

67 Vacuum Motor Provides suction so paper is held firmly

Solenoids

3 Original Pressure Solenoid Presses the original pressure plate

20 Master Eject Solenoid Moves the master eject roller to contact

26 Master Eject Clamper

Solenoid

28 Master Feed Clamper

Solenoid

31 Reverse Roller Solenoid Releases the clutch to rotate the

35 Paper Feed Solenoid Releases the paper feed sector gear to

39 Printing Pressure Solenoid Moves the press roller against the drum. F-8
52 Ink Supply Solenoid Releases the spring clutch to activate

56 Drum Lock Solenoid Prevents removal of the drum unit

NAME FUNCTION P to P

LOCATION

section.

eject box.

section.

feed roller and the drum to adjust
vertical image position.

paper delivery unit components.

leading edge from the drum.

on the transport belt.

down on the originals.

the drum surface.
Opens the master clamp to eject the

master.
Opens the master clamp to clamp the

master.

reverse roller.

rotate the paper feed roller.

the ink supply pump.

unless the drum is at the original stop
position
(This solenoid can be used on the
VT2300/VT2500).

(VT2300/2500

(VT2300/2500

A-4

F-7

A-4

only)

F-8

F-4

F-7

F-5

A-4

only)

F-6

F-8

F-8

F-6

F-8

F-7

F-7

1-20

28 February ’91

INDEX

No.

NAME FUNCTION P to P

LOCATION

Switches

6 Right Cutter Switch Detects when the cutter position is far

right.

17 Left Cutter Switch Detects when the cutter position is far

left.

21 Master Box Switch Checks whether the master eject box is

installed correctly or not.

(VT2300/2500)

(VT2100/2130

29 Master Eject Unit Safety

Switch

Checks whether the Master Eject Unit
is closed correctly or not.

45 Master Cut Switch Informs the CPU to cut the master

paper leading edge.

(VT2300/2500)

(VT2100/2130

46 Scanner Safety Switch Checks whether the scanner unit is

closed correctly or not.

49 Drum Rotation Switch Informs the CPU to rotate the main

motor at 10 rpm.

50 Front Door Safety Switch Checks whether the Front Door is set

correctly or not.

51 Drum Safety Switch Checks whether the drum unit is set

correctly or not.

58 Paper Table Safety Switch Checks whether the paper table is

opened correctly or not.
63 Interlock Switch Releases the cover safety functions. F-4
65 Main Switch Turns the power on or off. B-1
68 Full Master Detecting

Switch

Informs the CPU when the master eject

box is full of masters.

(VT2300/2500)

(VT2100/2130

69 Pressure Plate Position

Switch

Informs the CPU when the pressure

plate has reached the home position.

(VT2300/2500)

(VT2100/2130

70 Memory/Class Switch Selects Memory or Class mode. C-4

(VT2300/2500

F-6

F-6

F-7
F-6

/2150)

F-4

F-8
F-7

/2150)

F-4

A-6

F-4

B-6

F-4

F-7
F-6

/2150)

F-7
F-6

/2150)

only)

1-21

28 February ’91

INDEX

No.

71 Skip Paper Feed Switch

(VT2300/VT2500)
Printing Density Switch
(VT2100 series)

72 ADF Safety Switch Check whether the ADF unit is set

Sensors

1 Original Registration

Sensor

2 2nd Original Sensor Detects when the original is set. A-3
10 Master End Sensor Informs the CPU when the plotter unit

12 Paper Size Detection

Sensor 3

13 Paper Size Detection

Sensor 2

NAME FUNCTION P to P

LOCATION

Adjusts paper feed interval to allow
time for user to remove prints.
Use to select the printing density
according to the type and quality of the
original.

correctly or not.

Informs the CPU when the original
leading edge reaches the exposure
glass.

runs out of master roll.
Detects the size of the paper set on the

paper table.

Detects the size of the paper set on the
paper table.

(VT2300/2500)

(VT2100/2130

(VT2300/2500

(VT2300/2500

(VT2300/2500

C-4
C-3

/2150)

B-4

only)

A-3

F-6

E-5

only)

E-5

only)

14 Paper Size Detection

Sensor 1

18 Master Buckle Sensor Detects the master buckle existence. F-6
22 Master Eject Sensor Detects when the used master is sent

24 1st Original Sensor Detects when the original is set in the

33 1st Drum Position Sensor Checks the position of the drum. F-8
34 2nd Drum Position Sensor Checks the position of the drum. F-8
37 Drum Rotation Sensor Supplies timing pulses to the main

41 1st Paper Exit Sensor Misfeed detector. A-5
42 2nd Paper Exit Sensor Misfeed detector. A-5
47 Drum Master Detection

Sensor

54 Paper Table Height

Sensor

Detects the size of the paper set on the
paper table.

into the master eject box.

ADF mode.

board.

Checks whether the master is on the
drum.

Detects when the paper table reaches
the paper feed position.

E-5

(VT2300/2500

only)

F-7

(VT2300/2500)

F-6

(VT2100/2130

/2150)

A-4

(VT2300/2500

only)

F-8

F-6

(VT2300/2500

only)

A-6

1-22

28 February ’91

INDEX

No.

57 Paper End Sensor Informs the CPU when the paper table

59 Paper Table Lower Limit

Sensor

69 Printing Pressure Sensor Informs the CPU when the printing

Printed Circuit Board

7 Power Supply PCB Rectifies 100V AC input and supplies

8 Thermal Head Drive

Control PCB

27 Ink Detection PCB Control the ink supply. F-7
40 AC Drive PCB Controls the AC component by relays. E-5
43 CCD PCB Converts the light intensity into the

44 A/D Conversion PCB Converts the analogue signal into the

48 Operation Panel Controls the LED performance and

53 Main Control PCB Controls all machine functions both

55 Image Processing PCB Controls the master processing

Printed Circuit Board

15 Paper Size Detection

Board

Counters

61 Copy Counter Keeps track of the total number of

62 Master Counter Keeps track of the total number of

Others

5 Fluorescent Lamp

Stabilizer
9 Thermal Head Plots the master with heat. F-2
25 Fluorescent Lamp Applies light to the original for exposure. A-3
32 Encoder Converts 16 image positions to 4 bit

64 Circuit Breaker Cuts the ac line off. B-1

NAME FUNCTION P to P

LOCATION

runs out of paper.

Detects when the paper table reaches
the lowest position.

pressure is applied.

DC voltage.
Supplies the power to the Thermal

Head according to the signal from the
scanner section.

electrical signal.

digital signal.

monitors the key operation.

directly and through other boards.

performance.

Detects the size of the paper set on the
table.

copies made.

masters made.

Stabilizes the power supplement to the
Fluorescent Lamp.

data.

(VT2300/2500)

(VT2100/2130

(VT2300/2500

F-5
B-6

/2150)

A-6

A-6

D-1

E-2

A-2

B-3

A-8

C-6

C-3

E-5

only)

A-7

A-7

B-3

F-7

1-23

28 February ’91

7. MECHANICAL COMPONENT LAYOUT

17 16 15 1413 109 8 7 6 5 4

18

19
20

21
22

23
24

1. Thermal Head

2. Platen Roller

3. Master Feed Roller

4. CCD

5. Lens

6. Reverse Roller

7. Ink Roller

8. Drum Unit

9. 1st Eject Roller

10. 2nd Eject Roller

1211

333231302928272625

21. Mirror

22. Master Eject Box

23. Exit Pawl

24. Air Knife

25. Delivery Table

26. Delivery Guide Plate

27. Vacuum Unit

28. Press Roller

29. Doctor Roller

30. 2nd Feed Roller

3

2
1

38

37
36

35

34

11. Original Pressure Plate
(2300/2500)

12. Pull-out Roller (2300/2500)

13. Separation Blade (2300/2500)

14. Original Feed Roller (2300/2500)

15. 1st Original Transport Roller

16. Exposure Grass

17. 2nd Original Transport Roller

18. Fluorescent Lamp

19. Original Exit Tray

20. Feed Sub Mirror

31. Lower Separation Roller

32. Separation Plate

33. Paper Feed Side Plate

34. Paper Feed Table

35. Paper Feed Roller

36. Upper Separation Roller

37. Ink Holder

38. Master Spool

1-24

SECTION 2

SECTIONAL DESCRIPTION

1. ORIGINAL FEED SECTION

1.1 OVERALL: VT2300/VT2500

[I] [G] [E] [B] [A]

28 February ’91

[J] [K] [L] [D] [C]

[J]: 2nd Original Transport Rollers
[K]: Exposure Glass
[L]: Fluorescent Lamp

There are two original feed modes in this model.

ADF Mode: The originals [I] set on the original table are detected by the

1st original sensor [A]. When the Master Making key is
pressed, the original pressure plate [B] presses the originals
down. The pull-out roller [C] starts moving the lowest original
forward at the same time. The lowest original is separated
from the other originals by the original feed roller [D] and the
separation blade [E]. When the 2nd original sensor [F] de­tects the original, the 1st original transport rollers [G] start
rotating. The rollers stop after the original activates the origi­nal registration sensor [H]. The 1st original transport rollers
start rotating again after the drum section completes the
preparation for the master making.

[F][H]

SADF Mode: The separation blade [E] is released in the SADF mode. The

original on the original table is fed to the starting position
when the 2nd original sensor [F] detects the original.

2-1

28 February ’91

1.2 OVERALL: VT2100/VT2130/VT2150

[I] [G]

[J] [K] [L] [H] [F]

[J]: 2nd Original Transport Rollers
[K]: Exposure Glass
[L]: Fluorescent Lamp
[H]: Original Registration Sensor

The original [I] set on the original table is detected by the 2nd original
sensor [F]. At the same time, the 1st original transport rollers [G] and 2nd
original transport rollers [J] start rotating and feed the original to the original
start position where is 12 mm far from the guide plate. The original
transport rollers start rotating again after the drum section completes the
preparation for the master making.

2-2

28 February ’91

1.3 ORIGINAL FEED DRIVE MECHANISM: VT2300/VT2500

[J]

[A]

[B]

(f)

(e)

[C]

(c)(d)

(b)

[D]

[E]

(a)

[I]

[H]

[G]

[F]

[J] [D]

The original transport rollers [A] are driven by the original transport motor
[B], which is a stepper motor. The original feed rollers [J] are driven by the
ADF drive motor [C] through a series of gears [(a) to (f)]. The ADF drive
motor is a dc motor. The pull-out rollers [D] are driven by the ADF motor
through a drive belt [E].

The original pressure plate [F] is pressed down on the originals by the
original pressure solenoid [G]. The separation blade [H] is moved up and
down by the ADF ON/OFF select switch [I].

2-3

28 February ’91

1.4 ORIGINAL FEED DRIVE MECHANISM: VT2100/VT2130
/VT2150

[G]

[F]

[I]

[H]

[A]

[B]

[E]

[D]

[C]

When the actuator [A] is pressed down by the original, the 2nd original
sensor [B] is activated and the original transport motor [C] starts rotating.
The rotation of the original transport motor is transmitted to belts [D] and [E]
to turn the lower first original transport roller and lower second original
transport roller. At the same time, both the upper original transport rollers
[F] contact the first and second lower original transport rollers due to
pressure from the springs [G]. The rollers rotate and the original is fed.

When the actuator [H] is pressed down by the original, the original
registration sensor [I] is activated and the original transport motor stops.

When the Master Making key is pressed, the original transport motor rotates
to read the original after the master eject process is finished.

The distance between the sensors is 50 millimeters. If the original
registration sensor is not activated within five seconds, "A" and
indications blink.

2-4

1.5 ELECTRICAL TIMING: VT2300/VT2500

(One Original):

Insert Original

2nd Drum Position Sensor

Master Making Key

1st Original Sensor

Fluorescent Lamp

ADF Drive Motor

Original Pressure Solenoid

2nd Original Sensor

Original Registration Sensor

Original Transport Motor

Master Feed Motor

Read Command

T1

T2

T3

425 ms

T7

T4

Drum
Rotates

120°

T5

Original Feeds 25 mm

T6

Original
Feeds 14 mm

Master Feeds 438 mm

28 February ’91

T4:

Exposure Glass

Original Stop Position

12 mm

Scanning Position

16 mm

Original

Guide Plate

T1: When originals are inserted in the ADF unit, the 1st original sensor is

activated.

T2: When the Master Making key is pressed, the ADF drive motor starts

rotating and the pull-out roller and original feed roller feed the 1st

original. At the same time, the original pressure solenoid is energized

and the pressure plate presses the originals against the pull-out

rollers.

T3: When the 2nd original sensor detects the original, which is separated

by the separation blade and the original feed roller, the original

transport motor starts rotating and the transport rollers start rotating.

T4: One original is fed and when the original registration sensor detects

the original, the original transport motor stops the original position is

then as shown above.

T5: After the master eject process is finished and the second drum

position sensor is activated, the drum rotates 120 degrees more and

then the original transport motor turns on.

2-5

28 February ’91

T6: After the original is fed 14 millimeters, master feeding and master

making start.

T7: The ADF drive motor and the original pressure solenoid are turned off

425 mseconds after the 2nd original sensor detects the original.

If 2nd original sensor is not activated within 2.3 seconds after

pressing the Master Making key, the Original Misfeed indicator (A +

) will start blinking.

2-6

(Make-up mode): VT2500 only

Insert

Command

Sheet

Command Sheet Transportation

28 February ’91

Original
Transportation

Master Making Key
1st Original Sensor

Fluorescent Lamp

ADF Drive Motor

Original Pressure Solenoid

2nd Original Sensor

Original Registration Sensor

Original Transport Motor

Read Command

(Command Sheet)

Read Command (Original)

Make-up Key

T4:

T1

T0

T2

T3

41.6 msec

2 mm

Scanning Position

T4

16 mm

425 msec

Original Feeds

25 mm

Original Feeds

2 mm

Command Sheet

Guide Plate

Master Ejecting Start

425 msec

T5

T0: When the Make-up key is pressed, the fluorescent lamp turns on.

T1: When the original is inserted with a command sheet, the 1st original

sensor is activated.

T2: When the Master Making key is pressed, the ADF drive motor turns

on and the command sheet is fed by the pull-out rollers and the
original transport rollers. At the same time, the original pressure
solenoid is energized and the original pressure plate presses down
on the original and the command sheets.

T3: The original transport motor starts rotating when the 2nd original

sensor is activated by the command sheet.

T4: The reading command is output when the command sheet is fed

2mm past the scanning position.

T5: The original transport motor stops rotating when the command sheet

is fed 25 mm past the original registration sensor. At the same time,
the reading command turns off. The ADF drive motor and the original
pressure solenoid turn on at the same time and the original is fed.

2-7

28 February ’91

1.6 ELECTRICAL TIMING: VT2100/VT2130/VT2150

Original Set Master Making Key "ON"

2nd Drum Position Sensor

2nd Original Sensor

Original Registration Sensor

Original Transport

Fluorescent Lamp

T1

T2

Drum Rotation Degree

o

120

T3

T5

Reading Command

Master Feed Motor

T2:

No Image Area:

10 mm

Scanning Position

NOTE: The original stops 12 millimeters

16 mm

away from the corner of the

12 mm14 mm

lower guide plate edge [A].

Original Feed

Length (14 mm)

[A]

T4

Master Feed Length
(438 mm VT2100/VT2130)
(371 mm VT2150)

T1: When the 2nd original sensor detects the original, the original

transport motor starts rotating.

T2: One original is fed and when the original registration sensor detects

the original, the original transport motor stops the original position is

then as shown above.

T3: After the master eject process is finished and the second drum

position sensor is activated, the drum rotates 120 degrees more and

then the original transport motor turns on.

T4: After the original is fed 14 millimeters, master feeding and master

making start.

T5: The master feed motor stays on until it feeds the master 437 mm.

The original transport motor stops when the master feeding stops. At

that time the fluorescent lamp also turns off.

2-8

28 February ’91

1.7 CIRCUIT:

Original
Registration
Sensor

2nd Original
Sensor

Original
Transport Motor

M

Image

A/D
Conversion P.C.B.

1
3

2

1
3

2

5V
CN603-1

CN603-4

CN603-2
GND

CN603-3

CN601-13

CN601-11

CN601-25

(CN601-27)

CN601-17

CN601-18

CN601-19

CN601-20

CN601-21

Processing

P.C.B.

CN403-13

CN403-11

CN403-25

(CN403-27)

CN403-17

CN403-18

CN403-19

CN403-20

CN403-21

Fluorescent Lamp

VT2300/VT2500 only:

1st Original

Sensor

ADF
Drive Motor

Original Pressure
Solenoid

ADF Safety SW

M

SOL

Stabilizer

CN611-1

CN611-2

CN612-1

CN612-2

1
3

2

CN604

Red

-1

CN604

Yellow

-3

CN604-2

Black

CN607-3+5V

CN607-5 CN601-3

CN607-4 (GND)

CN607-6
CN607-7

CN607-1
CN607-2

CN607-8
CN607-9

24V

+24V

CN601

-15

GND

+5V

CN601-5

+24V

CN601-1

CN601-7
CN601-9

CN403-15

CN403-3

CN403-5

CN403-1

CN403-7 (IN)
CN403-9 (OUT)

2-9

28 February ’91

1.8 OUTPUTS:

Signal Name I/O

A/D Conversion Board

CN No. Level

Fluorescent
Lamp O CN601-15

Reading
Command I

CN601-25

(CN601-27)

ADF Drive
Motor
(VT2300/VT2500)

I (CN607-6)

Original
Pressure SOL
(VT2300/VT2500)

O (CN607-2)

Original
Registration

O CN603-4

Sensor
2nd Original

Sensor I CN603-3

1st Original
Sensor
(VT2300/VT2500)

I (CN607-5)

0V

3V

24V

24V

7.5V

7.5V

0V

3V

0V

0V

0V

5 m

5 m

5V

Description

When the fluorescent lamp turns
on, the voltage of the CN601-15
is 3V.

When the CCD reads the original
the voltage of CN601-25
(CN601-27) is 0V.

When the ADF drive motor starts
rotating, the voltage of CN607-6
is 0V.

When the original pressure
solenoid is energized, the voltage
of CN607-2 is 0V.

When the original registration

sec

sensor is activated, the voltage of

0V

CN603-4 is 0V.
When the 2nd original sensor is

sec

activated, the voltage of CN603-3

0V

is 0V.
When the 1st original sensor is

activated the voltage of CN607-5
is 5V.

( ): VT2300/VT2500

2-10

2. OPTICS/IMAGE PROCESSING

2.1 OVERALL

28 February ’91

[D]

Thermal Head

[E]

[F]

[C]

Thermal Head
Control

Operation Panel

[A]

A/D Converter

Image Processing

Main Board

[B]

[C]: Shading Plate
[D]: Mirror
[E]: Exposure Glass
[F]: Fluorescent Lamp

The light reflected from the original goes through the lens [A] and is
changed to an electrical signal in the CCD [B].

The electrical signal from the CCD is converted from an analog signal to a
digital signal in the A/D converter.

The converted digital image data is modulated and edited (VT2500) and is
sent to the thermal head control PCB.

2-11

28 February ’91

2.2 LIGHT SOURCE

[B]

[D] [G]

[B]

[A][K]

[D] [C]

[F]

[A]

[E]

[H]

[I]

[J]

[G]: Exposure Glass
[H]: Lens
[I]: CCD
[J]: A/D Converter
[K]: Mirror

The high frequency fluorescent lamp [A] is used as a light source for the
high speed reading of 16 pixels/mm. The light exposes at two angles using
a sub mirror [B] to prevent the shades at the edges of paste-ups on the
original [C]. The original guide plate [F] blocks part of the direct light from
the fluorescent lamp to make the light intensity of both direct and reflected
light the same. A heater [E] is wrapped around the fluorescent lamp. It
prevents light intensity reduction due to low temperature.

<Fluorescent Lamp>

Form: 15.5 ∅ x 436 mm
Lamp Voltage : 59 ± 6 V

---- Platen Cover ----

The platen cover [D] is used as a standard white level reference to correct
for shading distortion.

2-12

2.3 LENS

28 February ’91

Original
Surface

312.5∅

5 mm

404.179 mm

Exposure Glass

30.655 mm

[A]

29.895 mm

35∅ mm

[B]

[C]

This consists of 6 lenses, to transfer the image, correctly oriented, to the
photoelectric elements of the CCD. It is possible to adjust the focus by
moving the lens assembly [A].

<Lens>

Focal distance: 43 mm (43.05 ± 0.32 mm)
F No.: F4.5

The above illustration shows the layout to transfer the image from an A3
original (297 millimeter width) to the CCD [B].

<CCD>

Number of effective pixels: 5000 pixels
Reading length: 312.5 mm
Photo signal storage time: 3 msec.

The shading plate [C] corrects light intensity distortion. The light intensity is
low at the both ends of the lamp and is also low at the edge of the lens.
Therefore, the center light is cut to make the light intensity uniform.

2-13

28 February ’91

2.4 CCD (Charge Coupled Device)

Shift Registor

Shift Gate

D
31

Shift Gate

Shift Registor

10

φ1E

13 14

S1 S2

D35D34D33D

32

9

1 8

SSφ10φ2Bφ2CRS

15

SSSSφ20

RS2

OS2

OS

RS1

OS1

OD φ2E

18

20

2

5

3

19 17 21

22

φ1Bφ1C

D18D19D

20

6

4

CCD (16 dots/mm) φ1E, φ2E Clock (Phase 1)

φ10, φ20 Clock (Phase 2)

Light
Energy

Shift
Electrode

01B : Final Clock (Phase 1)
02B : Final Clock (Phase 2)
SH : Shift Gate

Photo
Diode

Shift Register

Storage
Electrde

RS : Reset Gate
OS : Output Transistor source
OD : Output Transistor Drain
SS : Sub-straight (Ground)
IS : Input Source (Test Pin)
IG : Input Gate (Test Pin)

7

IS

12

SH

16

IG

This is a solid-state device similar to a photodiode array, but unlike a photo­diode array, a CCD can read one complete scan line at a time. The CCD
produces an analog signal which is converted into a digital signal for image
processing.

2-14

28 February ’91

2.4.1 Function

The principle circuit of each pixel in the CCD is shown above. The light
reflected from the original is absorbed in the photodiode and the capacitor
stores the charge corresponding to the light intensity.

The CCD is composed of many such pixel elements in series. The image
signal of each pixel element is stored in the shift register as a charge.

When the SH signal is input, the image signal stored in the shift register, is
output in serial as the OS signal.

SH : Shift Gate
The storage electrode charge in the exposure section is transmitted to the
shift register by the shift gate pulse.

φ1E, φ2E Clock (Phase 1)

This is the transmission clock for analog shift register 2 (even pixels).

φ10, φ20 Clock (Phase 2)

This is the transmission clock for analog shift register 1 (odd pixels).

The shift gate signal transmits the electrical charge in parallel to either
analog shift register 1 or 2 (odd or even pixels). At the same time, the photo
signal storage of the next scan line starts in the exposure section.

The transmission clocks serially shift the electric charge transmitted to the
shift register, which outputs it from the OS (output signal) terminal.

2-15

28 February ’91

2.4.2 The Image Signal :

CCD Board

+12V

GND

CN801-2

RS

CN801-4

OS

CN801-6

1B

CN801-8

2B

CN801-12

20

CN801-14

10

CN801-16

2E

CN801-18

1E

CN801-20

SH

CN801-9, 10
CN801-1, 3, 5, 7, 11, 13, 15, 17, 19

CN602-1, 3, 5, 7, 11, 13, 15, 17, 19

CN602-2
CN602-4
CN602-6

CN602-8
CN602-12
CN602-14
CN602-16
CN602-18
CN602-20

CN602-9, 10

A/D Converter

A/D Converter

Input

Output

∅10, ∅1B, ∅1E (CN801-14, 6, 18)
∅20, ∅2B, ∅2E (CN801-12, 8, 16)

LSYNC (5,120)

{

SH

∅10, ∅1B, ∅1E

∅20, ∅2B, ∅2E

RS

OS

{

SH (CN801-20)

RS (CN801-2)

OS (CN801-4)

3 ms (5,120 Count)

4,096

Photo Signal Storage Time (3 ms)

Dummy

Pixels 32

Effective

Pixels

5,000

Dummy Pixels 4

Empty Data 84

5,120

Dummy Pixels:The dummy pixels generated by the area covered with alumi-

num film. The dummy pixels are used as the standard black
level.

The first 32 pixels read (D0 to D31) are dummy pixels. Pixels D32 to
D5,032 are the effective pixels (S1 to S5,000). After that there are four
more dummy pixels. Therefore, the total pixel count from the CCD, including
the dummy pixels, is 5,036.

As the image signal captured by the CCD is clocked out by the shift gate
every 3 ms (scan line period), there remains time for 84 transmission clock
pulses after all the image data from the CCD has been output. These clock
pulses, after all valid data have been clocked out, constitute empty data.
During this period, subscanning occurs.

2-16

2.5 A/D CONVERSION BOARD

Outline: VT2100/VT2130/VT2150 Circuit

Original

28 February ’91

VPH

Peak
Hold

PKHTM

CCD
Board

Selector 1

80%

53%

6%

PHOTO SHMRT

OS

Selector 2
0

1
2
3

0
1
2
3

A B

Signal Conversion
Direct Current Clamp
Amplification

Counter

CK

LUF

4-bit A/D
Conversion

VH VL

Current
Voltage
Conversion

4 bit

Black Level
Correction

Image
Processing

P.C.B

4 bit

Shading
Distortion
Memory

8-bit D/A
Conversion
VR(+) VR (-)

Selector 2

0: Shading Distortion Correction in Photo mode
1: Shading Distortion Correction in Line mode
2: Line mode
3: Photo mode

The CCD reads the light of the fluorescent lamp reflected from the original.
The CCD and A/D conversion boards convert the analog signals into digital
signals which are transmitted to the image processing board.

2-17

28 February ’91

2.5.1 CCD Output Signal Conversion, DC Clamping, Amplification:

VT2100/VT2130/VT2150 Circuit:

+12V

602-4

DCREST

OS

a

SH

Approx. 6V

OS

-12V

+12V

Q607

C669

DC Clamp
Switch

6V

IC628

4.7K

2.2K

IC624

2

_

6

3

+

b

1.7V 1.7V

(VT2300/VT2500:

VR600

R2

IC620

+

_

+5V

TP600

V0

c

IC624-6

Approx. 1.7V

(VT2300/VT2500: 1.4V)

SH

1.7V

(VT2300/VT2500: 1.4V)

DCREST

14 pixels

1). Signal Conversion

The CCD output (OS) varies according to the reflected light intensity and is
clipped at 6 volts. The output signal is then buffered, inverted and amplified.

2-18

28 February ’91

2). DC Clamping

The OS signal is amplified by Q607. The dc clamping switch is turned
ON/OFF by the DCREST signal. The switch turns on when the CCD
produces black level (empty data) at the end of scanning and is off during
image scanning.

When the switch turns on, the black level signal is stored in capacitor C669.
When the switch turns off, the black level signal is input to IC624 pin 3
while the image signal is input to the IC624 pin 2.

The difference between the image signal and the black level signal is
amplified and output from the IC624.

This output signal from IC624 is amplified again in IC620. The signal then
goes in the A/D converter.

2-19

28 February ’91

2.5.2 Peak Hold:

CCD Board A/D Conversion Board

CCD

Image
Processing
Board

Read

Write

S LSYNC

S CLK

OS

(CN403-27)

CN403-25

(CN403-29)

CN403-27

(CN403-31)

CN403-29

(CN403-33)

CN403-31

Inverter Amp

Timing
Signal
Generator

( ): VT2300/VT2500

Vo

PKHTM

PKHST
BLSET

SHMRT

A/D Conversion

SW2

Peak Hold
Circuit

A/D Conversion

VPH

This circuit holds, at different stages of image processing, the peak white
levels for both the original and the platen cover (standard white). The peak
white, or maximum, level is stored as charge on a capacitor. The peak hold
circuit is cleared by discharging the capacitor.

1). Platen Cover Peak Hold (Standard White)

The platen cover peak hold is used as standard white when processing
data to create the shading distortion data, which is later stored in memory.
This data is used to correct such distortions as bright or dull spots on the
lamp or variations in the CCD output. To create the platen cover peak hold
(standard white), the peak hold circuit stores the maximum level from five
scan lines of the platen cover.

2). Original Background Peak Hold

The maximum white level of the original, stored in the peak hold circuit, is
used to shift the threshold voltage of the D/A converter to match the original
background. An area of the original, 64 mm wide (from S2,048 to S3,072),
is read. This corresponds to a small size original.

3). Peak Hold Set Signal

The peak hold set signal (PKHST) clears the peak hold circuit. The peak
hold timing signal (PKHTM) turns on the analog switch (SW2) allowing the
image signal to be applied to the peak hold circuit.

2-20

4) Peak Hold Signal Timing:

L. SYNC
CN403-29

(CN403-31)

Reading
CN403-25

(CN403-27)

Write Out
CN403-27

(CN403-29)

SHMRT

PKHST

PKHTM

5 lines

5 lines

A

BLSET

SW2

Correction Timing
P.H. Signal Input
Timing

ON OFF ON OFF

( ): VT2300/VT2500

A Section (Main Scanning)

LSYNC

PKHTM

0

Original Background
Peak Hold

2080 3140 4096 5120

1024

Image
Reading

Pixels (64 mm width in the middle)

28 February ’91

2.5.3 Shading Distortion Correction:

Amp

Pixels Data

PKHTM SW2

Peak
Hold
Circuit

L. SYNC CN403-29

(CN403-31)

Read CN403-25

(CN403-27)

Write CN403-27

(CN403-29)

SHMRT

VPH

53%

B

1 X

Y1

Current/
Voltage
Convertor

VT2100/2130/2150: 1.7V
VT2300/VT2500: 1.4V

5 lines

VH

A/D
Converter

VL

D/A
Converter

VR(+)

4 bit Signal

Shading
Distortion
Memory

4 bit Signal

VR(-)

1.7V: VT2100/2130/2150

1.4V: VT2300/VT2500

SHMRT

PKHST

PKHTM

BLSET

( ): VT2300/VT2500

Shading Distortion Memory

Since the output of the CCD varies according to both the CCD and the
intensity of the fluorescent lamp, shading distortion is corrected electrically
as well as mechanically (shading plate).

2-22

1). Shading Distortion Memory

White Peak Hold of Platen Cover

VPH

28 February ’91

VT2100/2130/2150: 1.7V

VT2300/2500: 1.4V

Memory

100%

53%

5,000 pixels

4 bits

When reading the white level of the platen cover, the peak hold (standard
white) is determined using the five scan lines.
The shading distortion data is stored in memory during the fifth scan line .

The potential difference between the output of each pixel and the 53% level
of the peak hold is converted by an A/D converter into 4-bit data. This data
is stored in a memory location corresponding to the pixel.

2). Shading Distortion Correction

White Peak Hold of Original Background

VPH

Correction Memory

100%

53%

VT2100/2130/2150: 1.7V

VT2300/2500: 1.4V

4 bits for
distortion memory

Fixed 4 bits

When reading the original, the distortion data corresponding (stored in
memory) to each pixel is converted from digital to analog, using the D/A
converter, and used as the reference voltage (VH) of the A/D converter.

The D/A converter is an 8-bit converter with 4 of its 8 bits fixed. This
ensures that the output of the D/A converter is always greater than 53% of
the reference voltage (VR+).

2-23

28 February ’91

The reference (VR+) of the D/A converter is set to the peak hold of the
original background. Distortion correction is obtained by using the output
voltage of the D/A converter as the reference voltage (VH) of the A/D
converter; therefore, distortion correction also corrects for the original
background level.

For Example: If the light intensity at a certain pixel is very high, then a high
voltage level will be stored in the distortion memory location for that pixel.
When reading a document, that high voltage level is used as the reference
level (VH) of the A/D converter. Therefore, during conversion, the input level
from the pixel is compared to a high voltage by the A/D. This negates any
errors caused by the high light intensity at that pixel.

2-24

2.5.4 Original Background Correction

VT2100/2130/2150: 1.7V

VT2300/2500: 1.4V

White Peak Hold of Platen Cover

VPH

28 February ’91

<Original background is lighter.>
Peak Hold of Original Background

VPH

53%

53%

<Original background is darker.>
Peak Hold of Original Background

VT2100/2130/2150: 1.7V

VT2300/2500: 1.4V

VPH

53%

VT2100/2130/2150: 1.7V

VT2300/2500: 1.4V

As the white peak hold of the original background is used as the reference
(VR+) of the D/A converter, the overall shading distortion correction level is
adjusted for the original background at the output of the D/A converter.

For Example, if the background level of the original is low, the reference
level (VH) of the D/A converter is low, causing the overall distortion
correction level to be low. Therefore, even though the light level from the
original background is low, it is being compared to a low reference level
(VH) which causes it to be detected as background, not image.

2-25

28 February ’91

2.5.5 Black Level Correction (Line mode only)

Selector 1 0

1
2
3
4
5
6

Counter

CK

Amp.

VT2100/2130/2150: 1.7V

VT2300/2500: 1.4V

Selector 2

Y3

VS

4-bit A/D Conversion

LUF

VL

The black level correction compensates for the image density. Black level
correction is used only when in line mode.
The lower threshold level (VL) of the A/D converter is set according to a
high density original or a low density original.

At first, the black level reference of the A/D converter is set to 35% of the
original peak hold white level (PH) because the analog switch of selector-1
is set to the "0" position.
If while reading the original image the black level of the image is lower than
VL (PH x 35%), the A/D converter outputs the LUF signal.

The LUF signal is applied to selector 1 as a clock pulse. The LUF signal
increments the counter of selector 1 from 0 to 1. This changes the VL to
30% of PH. If the LUF signal is again applied to the counter of selector 1,
incrementing it from 1 to 2, the analog switch of selector 1 changes from 0
to 1.

The following table shows the number of clock pulses needed to increment
the analog switch of selector 1.

Counter (4 bit) Selector 1 Switching VL

0.1 SW 0 PH x 35 %

2.3 SW 1 PH x 30 %

4.5 SW 2 PH x 25 %

6.7 SW 3 PH x 20 %

8.9 SW 4 PH x 15 %
A.B SW 5 PH x 10 %
C.D SW 6 PH x 5 %
E.F SW 7 PH x 0 % (Black Level)

2-26

2.5.6 A/D Conversion

28 February ’91

VH
(White Standard)

OS

4 bit A/D
Convertion

VT
(Black Standard)

65%

35%

VT2100/VT2130/VT2150 Circuit:

Amp

VPH of Platten/
Original

Background

VPH of Shading
Distortion
Memory

Black Level
Correction
Output of
Selector 1

SW

VPH x 80%

VPH x 53%

VPH x 6%

PHOTO

Back Ground (White Peak)

A B

Selector 2

0

1

2

X

3

0

1

Y

2

3

A B

A B

0

BAD1

1
2
3

BAD2

4
5
6

BAD3

7
8
9

BAD4

10
11
12
13
14
15

BAD1

BAD2

BAD3

BAD4

1

0

1

0

0

0

1

0

VS

VH

M1

M2

VL

A/D CONVERSION

SHMRT

PHOTO SHMRT

Selector 2 (X,

Y)
Shading Distortion Correction (Photo Mode) L L SW0 ON
Shading Distortion Correction (Line Mode) H L SW1 ON
Photo Mode L H SW2 ON
Line Mode H H SW3 ON

This circuit converts the analog input signal (VS) to a 4-bit digital signal
using both the white level reference (VH) and the black level reference (VL).

In each mode, the settings of the "X" and "Y" switches in Selector 2 are
automatically determined by the PHOTO and SHMRT signals as shown in
the above table.

2-27

28 February ’91

VT2300/VT2500 Circuit:

Amp

Photo Mode

VPH of Shading
Distortion
Memory

VPH of Platten/
Original
Background

Black Level
Correction
Output of
Selector 1

Standard
Voltage: 1.4V

CN601-24

CN601-25

Density: 0

Density: 1

95%

80%

80%

70%

10%

10%

40%

40%

70%

40%

20%

Selector

3

2

1

0

3

2

1

0

Line Mode
Selector

3

2

1

0

3

2

1

0

A B

A B

X

Line/Photo

Selector 2

3

2

X

Y

53%

X

Y

1

0

3

2

Y

1

0

AB

PHOTO

SHMRT

VS

VH

M1

M2

VL

A/D CONVERSION

4 bit
Image
Signal

Line/Photo

PHOTO SHMRT

Selector 2 (X,

Y)
Shading Distortion Correction (Photo Mode) L L SW0 ON
Shading Distortion Correction (Line Mode) H L SW1 ON
Photo Mode L H SW2 ON
Line Mode H H SW3 ON

This circuit converts the analog input signal (VS) to a 4-bit digital signal
using both the white level reference (VH) and the black level reference (VL).

In each mode, the settings of the "X" and "Y" switches in Selector 2 are
automatically determined by the PHOTO and SHMRT signals as shown in
the above table.

2-28

1). Shading Distortion Correction -- (Selector 2 Switch 1 ON)

28 February ’91

Peak Hold of
Platen Cover

VPH

VPH x53%

VT2100/2130/2150: 1.7V

VT2300/2500: 1.4V

(Black Level)
(Black Level)

Waveform of
Platen Cover

4-bit A/D
Conversion

When reading the platen cover to establish the shading distortion data, the
high reference voltage (VH) of the A/D converter is set to the peak hold
level and the low reference voltage (VL) is set to 53 % of the peak hold
level. Therefore, the potential difference between the output of each pixel
and the 53% level of the peak hold is converted by the A/D converter into
4-bit data. The shading distortion data for each pixel is stored in a memory
location corresponding to that pixel.

2). Original Reading

Peak Hold of
Background

VPH

VH
(Corrected Waveform)

VL (VPH x 35%~0%)

VT2100/2130/2150: 1.7V

VT2300/2500: 1.4V

(Black Level)
(Black Level)

a). Line Mode -- (Selector 2 Switch 3 ON)

The reference voltage (VH) of the A/D converter is set to the output of
the D/A converter (converted shading distortion data) for each pixel be­ing read. Because the reference level of the D/A converter is set to the
original peak hold level, this corrects for shading distortion as well as
matching the output level to the original background.

Also, as described in "Black Level Correction", VL is set from 0% to
35% of the potential difference between 1.7 volts (VT2300/2500: 1.4
volts) and the peak hold of the original background. Black level
correction varies according to the original image density.

2-29

28 February ’91

Peak Hold of Background

(Corrected Waveform X 80%)

VPH

VH (Corrected

Waveform x 80%)

VL (VPH x 6%)

VT2100/2130/2150: 1.7V

VT2300/2500: 1.4V

(Black Level)
(Black Level)

b). Photo Mode -- (Selector 2 Switch 2 ON)

The VH of the A/D converter is set to 80% of the potential difference
between 1.7 volts (VT2300/2500: 1.4 volts) and the output from the D/A
converter (converted shading distortion data). This corrects for shading
distortion as well as matching the output level to the original back­ground because the reference level of the D/A converter is set to the
original peak hold level.

Also, VL is set to 6% of the potential difference between 1.7 volts
(VT2300/2500: 1.4 volts) and the peak hold level of the original.

2-30

2.5.7 Printing Density Change

VT2100/VT2130/VT2150 Circuit in Line mode:

Image Signal

28 February ’91

Shading Distortion
Memory Correction
Signal

Selector 1
Output
Black Date
Correction

3

3

Selector 3

3

73%

5

67%

6

47%

1.7V

COM

A/D Converter

VH

VL

1

A/D

Converter

5V

A

B

C

LUF

VS

4 bit
Image
Signal

CN606-2

CN606-3

CN606-5

CN606-1

CN606-4

Gate

5

3

Printing

1

Density

S.W.

2

4

4 bit
Image
Signal

SW ON

(Terminal No.)

CN606

-2 -3 -5

Selector 3

MANUAL 1 1-2 H H L COM--3
MANUAL 2 2-3 H L H COM--5

Standard ---- H H H COM--1

MANUAL 3 4-5 L H H COM--6

The printing density can be changed by the printing density switch when in
the line mode. This switch changes the threshold level to 47 %, 67 %, or 73
% of the white level.
The selected threshold level enters port VL while the shading distortion
corrected image signal enters port VH of the A/D converter.
In manual printing density mode (Dark, Darker, and Lighter), the A/D
converter outputs either all "H" BAD signals (4 bit) or all "L" BAD signals (4
bit). This is determined by the LUF signal
When the image signal is lower than the threshold level, the LUF signal is
output from the A/D converter to make all BAD signals "H". Then the image
signal is output as a black.
When the image signal is higher than threshold level, LUF signal is not
output. Then the BAD signals are all "L".

2-31

28 February ’91

VT2300/VT2500 Circuit in Line Mode:

VPH of Shading
Distortion
Memory

Black Level Correction
Output of Selector 1

Standard Voltage: 1.4

CN601-24

CN601-25

Density : 0

Density : 1

70%

40%
20%

Line Mode
Setector

3
2
1

0

3
2

Y

1
0

A B

X

PHTO

Line/Photo
Selector 2

3

Y

3

B

A

X

A/D Converter

SHMRT

The printing density (i.e. image density) can be changed with the Printing
Density key on the operation panel.

Line Mode Selector changes the threshold level of VH (White level
reference) and VL (Black level reference) according to the density signals
from CN 601-24 and CN 601-25.

VH

VL

4 bit
Image
Signal

The A/D converter converts the analog input signal to a 4-bit digital signal
using both the white reference level (VH) and the black reference level (VL).

The following table shows the VH and VL levels that vary according to the
combination of the density signals in Line mode.

Printing

Density

Density

Signal 0

(CN601-

24)

Density
Signal 1
(CN601-

25)

Line Mode Selector

ON Channel.

A/D Converter

VH VL

Darker 2 H H 0X, 0Y 100% 40%
Darker 1 L H 1X, 1Y 100% 20%

Standard H L 2X, 2Y 100% 0~35%

Lighter L L 3X, 3Y 70% 0%

2-32

VT2300/VT2500 Circuit in Photo Mode:

Photo Mode
Selector

VPH of Shading Distortion
Memory

VPH of Platlen/
Original
Background

CN601-24

Density : 0

95%
80%
80%
70%

10%
10%

4%
4%

3
2

1
0

3
2
1
0

A B

X

Y

Selector 2

2

Y

2

A

B

28 February ’91

X

VH

M1

M2

VL

A/D Converter

4 bit
Image
Signal

CN601-25

Density : 1

(Low signal when in Photo mode)

PHTO

SHMRT

(Low signal when in Photo/Line mode)

The printing density (i.e. image density) can be changed with the Printing
Density key on the operation panel. This adjustment can also be done in
Photo mode to increase the image quality of photo originals.

Photo ode Selector changes the threshold level of VH (White level
reference) and VL (Black level reference) according to the density signals
from CN 601-24 and CN 601-25.

The A/D converter converts the analog input signal to a 4-bit digital signal
using both the white reference level (VH) and the black reference level (VL).

The following table shows the VH and VL levels that vary according to the
combination of the density signals in Photo mode.

Printing
Density

Density
Signal 0
(CN601-

24)

Density

Signal 1

(CN601-

25)

Photo Mode Selector

ON Channel.

A/D Converter

VH VL

Darker 2 H H 0X, 0Y 95% 10%
Darker 1 L H 1X, 1Y 80% 10%

Standard H L 2X, 2Y 80% 4%

Lighter L L 3X, 3Y 70% 4%

2-33

28 February ’91

2.6 REDUCTION PROCESSING:

Original
Transport
M

A/D Converter

BAD 1

BAD 2

BAD 3

BAD 4

24V

Motor
Drive
Circuit

CN403-17
CN403-18
CN403-19
CN403-20
CN403-21

4 bit
Image
Data

ORF0 A
ORF0 B
ORF0 C
ORF0 D
ORF0 E

Image Processing PCB

Image Data

Reduction
Processing

Discard Timing

Drive
Pulse
Generator

Image
Processing

Timing Signal
Generator

( ): VT2300/VT2500

CN-NO Signal I/O FROM 100 % 93 %

105-19

105-20

(105-21)

Reduction 0

(Magnification 0)

Reduction 1

(Magnification 1)

(Magnification 2) (I)

I Main PCB H L H L

I Main PCB H H L L

(Main
PCB)

(H) (H) (H) (H)

( ): VT2300/VT2500

Main PCB

CN
105-19

CN
105-20

(CN
105-21)

82 %

[75%]

Reduction 0

(Mag. 0)

Reduction 1

(Mag. 1)
(Mag. 2)

71 %

[64%]

Reduction in the main scanning direction is performed by systematically
discarding the pixels and the reduction in the sub-scanning direction is
performed by changing the transportation speed of the original.

2.6.1 Main Scanning Reduction:

Reduction Mode Discarded Pixels Remaining Pixels

100 % 0 Pixels All Pixels

93 % 1/14 Pixels 13/14 Pixels (0.929)

82 % (A4 version) 3/11 Pixels 9/11 Pixels (0.818)

75 % (LT version) 1/4 Pixels 3/4 Pixels (0.75)

71 % (A4 version) 2/7 Pixels 5/7 Pixels (0.714)

64 % (LT version) 5/14 Pixels 9/14 Pixels (0.642)

When the reduction command is sent from the main board, the timing signal
generator sends the thinning timing control signal to the reduction

2-34

28 February ’91

processing circuit. Some of the 4-bit image data from the A/D converter is
discarded according to the thinning timing control signal.

2.6.2 Movement:

Main scan direction: Examples (A4 version)

During the 71% reduction mode, 5 out of 7 pixels are used; 1 pixel is
discarded each cycle.

0 1 2 3 4 5 6 0 1

7 pixels

Before thinning

5 pixels

0 1 2 3 4 5 0 1 2

After thinning

(2nd and 5th pixels are removed.)

During the 82% reduction mode, 9 out of 11 pixels are used; 2 pixels are
discarded each cycle.

0 1 2 3 4 5 6 0 1

11 pixels

7 8 9 10

Before thinning

9 pixels

0 1 2 3 4 5 0 1 2

After thinning

36 7 8

(3rd and 8th pixels are removed.)

During the 93% reduction mode, 13 out of 14 pixels are used; 1 pixel is
discarded each cycle.

Before

0 1 2 3 4 5 6 11

14 pixels

7 8 9 10

12 13

thinning

6th pixels is removed.

13 pixels

After

0 1 2 3 4 5 010 12

9

116 7 8

thinning

2-35

28 February ’91

2.6.3 Sub-scanning Reduction:

5V

E Phase

D Phase

Original Transort Motor

∅A CN605-1

∅B CN605-3

C Phase

A Phase

B Phase

CN605-1

CN605-2
CN605-3

CN605-4

CN605-5

CN605-6

CN605-7

CN605-8

CN605-9

CN605-10

0A

24V

0B

0C

0D

0E

Transort Motor
Drive Circuit

A/D Converter Image Processing PCB

t

0 1 2 3 4 5 6 7 8

CN403-17

CN403-18

CN403-19

CN403-20

CN403-21

9

10 11 12

Motor
Drive
Timing
Pulse
Generator

CK

Timing
Pulse
Generator

13

∅C CN605-5

∅D CN605-7

∅E CN605-9

1 line

(1/16 mm)

NOTE: The reduction ratio change is performed by changing the pulse

width "t".

2-36

28 February ’91

Reduction
Ratio

100% 1.484 ms 674 ---- 0.742 ms 1348 ----

93% 1.378 ms 726

82% 1.214 ms 824

75% 1.112 ms 899

71% 1.060 ms 944

64% 0.950 ms 1053

Pulse Width PPS Pulse Width PPS

Original Transportation Command Sheet Transportation

674

= 0.928 0.689 ms 1451

726
674

=0.818 0.607 ms 1648

824
674

=0.74 0.556 ms 1798

899
674

=0.714 0.530 ms 1888

944
674

1053

=0.64 0.475 ms 2106

2 3 4 5 6 7 8 9 10 11 12 1310

A Phase

B Phase

1348
1451

1348
1648

1348
1798

1348
1838

1348
2106

=0.928

=0.818

=0.749

=0.714

=0.640

C Phase

D Phase

E Phase

When the reduction command is sent from the main board, the frequency of
the pulses from the pulse generator increases. The drive pulse generator
then increases the frequency of the motor drive pulses to increase the
motor rotation speed.

2-37

28 February ’91

2.7 Enlargement Processing: VT2300/VT2500

In reduction processing, pixels are discarded according to the selected
reduction ratio. In enlargement processing, pixels are added.

Enlargement processing requires main scanning enlargement and
sub-scanning enlargement.

Main Scanning : Main scanning is performed by systematically

adding pixels according to the enlargement ratio.

Sub-Scanning : Sub-scanning is performed by changing the original

transportation speed according to the enlargement ratio.

2.7.1 Main Scanning Enlargement

When the magnification command is sent from the main control board
(CN402-19, 20, 21), the timing signal generator in the image processing
board sends the adding timing control signal. Pixels are added to the 4-bit
image data from the A/D converter according to the adding timing control
signal.

Enlarge Mode Added Pixels Pixel Ratio
115% (LT/A4 Version) 2 Pixels 15/13 Pixels (1.154)
122% (A4 Version) 3 Pixels 17/14 Pixels (1.214)
127% (LT Version) 3 Pixels 14/11 Pixels (1.273)
141% (LT/A4 Version) 9 Pixels 31/22 Pixels (1.409)

2-38

28 February ’91

Examples:

In 115% enlarge mode, the 7th pixel and the 13th pixel data are doubled to
produce 15 pixels. This is repeated each main scan cycle.

: Added Data

3 4 5 6 7 8 9 10 11 12 13 14
3 41 2

3 4 5 6 7 8 9 10 11 12

5

7

6

7

8

9

10

11

13

12

1

13 3

15
13

2

1

Enlarge

Full Size

1 2

1 2 4 5

In 122% enlarge mode, the 5th, 10th, and 14th pixels are doubled to
produce 17 pixels. This is repeated each cycle.

: Added Data

3 4 5 6 7 8 9 10 11 12 13 14
3 41 2

3 4 5 6 7 8 9 10 11 12 13

5

5

7 8

6

9

10 10

12

11

14 1 2

15

13

16 17

14

Enlarge

Full Size

1 2

1 2

14

3

32

1

4

In 127% enlarge mode, the 4th, 8th and 11th pixels are doubled to produce
14 pixels. This is repeated each cycle.

: Added Data

3 4 5 6 7 8 9 10 11 12 13 14 1 2 31 2

Enlarge

Full Size

1 2

3 41 2

4

6

5

7

3 4 5 6 7 8 9

2-39

10 11 31 2

8

9

10 11 1 2 3

118

4 5 6

28 February ’91

In 141% enlarge mode, the 3rd, 5th, 8th, 10th, 13th, 15th, 18th, 20th, and
22nd pixels are doubled to produce 31 pixels.
This is repeated each cycle.

: Added Data

Enlarge

Full Size

3 4 5 6 7 8 9 10 11 12 13 141 2

3 5

3 41 2 6 7

1 2

15

16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

5

534

7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 3 4 5 6 7 8 9 10 11 12 131 26

10 118 9 12 14 15 16 17 18

8 10 13

13

15

18 22

19 20

21 22 1 2 3 3

20

2-40

28 February ’91

2.7.2 Sub-scanning Enlargement

Enlargement in the sub-scanning direction is performed by decreasing the
original transportation speed.

When the enlargement signal is sent from the main control board, the
frequency of the pulses from the pulse generator decreases. (The pulse
length increases.) The drive pulse generator then decreases the frequency
of the motor drive pulses to decrease the motor rotation speed.

2-41

28 February ’91

2.8 IMAGE SIGNAL PROCESSING : BINARY CIRCUIT

The binary circuit produces 1-bit data (white or black) from the output of the
A/D converter (four-bit data) and sends it to the thermal head board.

2.8.1 Function

1) Line Mode:
MTF (Modulation Transfer Function) Correction Processing

2) Photo Mode:
Dither Processing (Graduation Processing) - 16 graduations
Edge Emphasis Processing (Selection of either MTF or Dither process­ing)

2.8.2 Outline

1) MTF Correction Processing

This is used to emphasize image signal data compared with surround­ing pixels. Emphasis data which varies according to the surrounding
pixels is compared to a fixed threshold level to determine if the pixel is
white or black.

When the surrounding pixels are
whiter than the pixel being processed

Main Scan

E , the pixel data E is converted to
appear darker than the real pixel data.

I H G

Sub Scan

F E D

C B A

This converted data is termed the em­phasis data.
Conversely, when the surrounding pix­els are darker than the pixel being
processed E , the pixel data E is con­verted to appear whiter than the real
pixel data.

E2 = 2E -- 1/2(D + F) ------ Main Scan Emphasis Data
E1 = 2E -- 1/2(B + H) ------ Sub Scan Emphasis Data

The emphasis data is compared to a threshold level to determine if the
pixel is black or white.

Emphasis Data E2 or E1 ≥ 7.5 ----- Black

Emphasis Data E2 or E1 < 7.5 ----- White

2-42

28 February ’91

2) Dither Processing

This is part of the artificial graduation system. As each pixel can only
be expressed by either black or white at print time, the dither process is
used to transform a graduated original into 4 x 4 arrays containing only
black and white pixels. Each pixel of the original corresponds to a loca­tion in the 4 x 4 dither matrix. During dither processing, the value of
each four-bit data signal from the A/D converter is compared to the
corresponding fixed threshold level (VTH) in the dither matrix and is con­verted to either black or white. This introduces graduations by changing
the ratio of black pixels to white pixels. The 4 x 4 dither matrix is stored
in the image processing ROM.

NOTE: The VT2300/2500 uses a 6 x 6 dither matrix that improves

the image quality in Photo mode.
(The VT2100/2130/2150 use a 4 x 4 dither matrix.)

E > VTH .................... Black

E ≤ VTH .................... White

Sub
Scan

Main Scan

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

4

5

5

5

5

5

5

5

5

5

4

7

14

8

4

7

14

9

11

13

14

14

9

11

13

14

3

1

0

6

2

5

12

10

8

4

7

3

1

0

6

2

5

12

10

0

9

5

11

13

14

7

14

0

9

5

11

13

14

8

4

3

1

6

2

12

10

8

4

3

1

6

2

12

10

4 x 4 dither matrix

Pixels 4-bit data to be read
Example: All pixels are at 5.

Threshold level of the
dither matrix (Number
shows each VTH).

Image reappearance
(Shaded pixels are
black.)

3) Selection of Dither Processing or MTF Correction During Photo Mode
(Edge Emphasis)

If characters are processed using the dither method, they will be dis­jointed and difficult to read due to the distorting nature of the dither
process. Therefore, when the density difference between a pixel and
the surrounding pixels is greater than the specified level, the data is
processed using MTF instead of the dither method.

2-43

28 February ’91

2.9 THERMAL HEAD PULSE GENERATOR:

Thermistor

Thermal Head

RANK 2

RANK 1

RANK 0

1

CN704-1

2

CN704-2

3

CN704-3

5

CN704-5

6

CN704-6

CN701 -1

Decoder

Thermal Head
Drive Control

+24V

-2

VHD (+16V)

-3

VHD (+16V)

-4

GND-B

-5

GND-B

-6

GND-B

PSU

CN702-19 CN404-19

CN702-17

CN702-15

CN702-13

CN702-11

CN702-7

CN404-17

CN404-15

CN404-13

CN404-11

CN404-7

+5V

Pulse
Generator

THENL

Image Processing PCB

1 line

LSYNC

4096 5120

t

THENL

ENL 1

(CN704-30)

ENL 2

(CN704-29)

ENL 3

(CN704-24)

ENL 4

(CN704-23)

Voltage to the thermal head is applied in 16 V pulses. The energy applied
to the thermal head is changed by changing the pulse width according to
the thermal head temperature and its resistance.

2-44

28 February ’91

1) Thermal Head Resistance
The resistance of the thermal head varies from one head to the an­other. Therefore, after installing a new thermal head, always recalibrate
the power supply unit according to the VHD ratings on the thermal
head cover.

2) Head Temperature
The thermal head contains a thermistor, which it detects the thermal
head temperature.
The detected temperature is sent to the pulse generator by a divided
rank signal.

Rank 1 2 3 4 5 6 7

Head Temp.

8.5°C

~

8 9 10 11 12 13 14

33°C

~

12°C~15.5°C~19°C~ 22.5°C

~

36.5°C~ 40°C~ 43.5°C~ 47°C~ 50.5°C

~

26°C

~

29.5°C

~

54°C

~

3) The pulse generator controls the pulse width based on the above ther­mal head resistance information and the head temperature information.

Wide

Pulse
Width

Narrow

8 1

High

Thermal Head Temp.

Low

2-45

28 February ’91

2.10 THERMAL HEAD DRIVE:

2.10.1 Function/Specification

The VT2130/VT2150 use the A4 size (216 mm width) thermal head and the
VT2100/VT2300/VT2500 use the B4 size (256 mm width) thermal head.

Thermal head • Memory length 256mm (B4)

216 mm (A4/LG)

• Number of thermal heating elements 4096 dots (B4)

3456 dots (A4/LG)

• Density of thermal heating elements 16 dots/mm

• Applied Voltage 16V(14~18V)

2.10.2 Thermal Head Outline

A thin-film type thermal element is used in the thermal head. The drive
circuit has a 1-line buffer for serial input. Each thermal element has direct
drive due to switching elements.

S1 (S11----S18): White/Black

pixel data

CK (CK1----CK4): To latch the

shift register

data
ENL: Record control
Va: Applied voltage (16V)
VDD: Power source (5V)

2.10.3 Power Lines

VCC/VHD/GND .... Applied voltage

Va

(16V)

VDD

VDD

VDD

1 2 3

126

128 bit LATCH

128 bit Shift Reg

127 128

VHD: As the resistance of the thermal elements varies depending on the thermal head, it

is necessary to adjust the applied voltage according to the average resistance of
the thermal head.
The thermal rating of each head is documented on the thermal head cover.
Therefore, after installing a new thermal head, always recalibrate the power supply
unit according to the VHD ratings on the thermal head cover. Adjust VHD using
VR201 on the power supply unit.

The drive circuit (LSIC) consists of the following: 32 x 128-bit shift
registers, 32 x 128-bit latches, logic gates, drive transistors, and 4096
heating elements. The thermal head is made up of 32 drive circuits
arranged in two rows of 16 elements.

NOTE: The thermal element used on the VT2130/VT2150 is narrower

than the B4 thermal head. Therefore, the shift registers, latches,
logic gates, and drive transistors located on both ends have been
deleted from the thermal head.

2-46

2.10.4 Movement

28 February ’91

P. DATA

Image Signal

P. CLK

P. LSYNC

THENL

Image
Processing

CN404-1 CN702-1

CN404-3 CN702-3

CN404-5 CN702-5

CN404-7 CN702-7

Thermal
Head Temp.
Checking
Circuit

Pulse Width
Decorder

Thermal Head Drive Control Thermal Head

Image Pixel
Data
Decorder

CN704-7

CN704-8

CN704-10

CN704-11

CN704-12

CN704-13

CN704-14

CN704-23

CN704-24

CN704-29

CN704-30

-10

-11

-12

-13

-13

-23

-24

-29

-30

-7
S 18

-8
S17

-9CN704-9
S 16

S 15

S 14

S 13

S 12

S 11

ENL 4

ENL 3

ENL 2

ENL 1

The temperature of the thermal head increases excessively when there is
consecutive black image data in the sub scanning direction. Conversely, the
temperature of the thermal head does not reach the proper point when
there is consecutive white image data before a solid fill.

Main Scanning

Image

Non Image

PDATA

(Previous Line)

PDATA

(Scan Line)
1st Output

2nd Output

Black Image Signal White Image Signal

• White image in previous scanning.

The same black image signal is out­put twice.
The first is for preheating.

• Black image in previous scanning.

A white image signal is output first to
reduce the thermal head tempera­ture.

2-47

28 February ’91

CN902-1

L: Black
H: White

H: Black
L: White

H: Black
L: White

Previous Line

Memory

1

3

IC a

2

Image Data

1

2

IC b

3

Previous Image Data

1st Output → H
2nd Output → L

The image data (P-DATA) of 1 scanning sent to the thermal head drive
control board is stored in the line memory. When the image data of the next
scanning is stored in the line memory, the previous stored line memory data
is output and processed with the image data of the next scanning at ICb.

Output

2-48

28 February ’91

Image
Data

P.LYNC

SIN 1

SIN 2

SIN 3

SIN 4

SIN 5

SIN 6

SIN 7

SIN 8

CK 1

CK 2
CK 3

CK 4

LATCH 1

LATCH 2

LATCH 3

LATCH 4

ENL 1

ENL 2

ENL 3

ENL 4

1st 2nd Pixel No.

1 128 1 128

129 129

257 257

385 385

513 513

641 641

769 769

897 897

128P S 128P S

1025 1025 2049 2049 3093 3093

1 line

4096 5120

1. When the clock signals (CK1 -- 4) enter the thermal head drive control
board, the 1024 pixels of image data are input into the shift register.
When the latch signal enters to the control board, the image data is
sent from the shift register to the latch in parallel.

2. Above operation is performed again.

3. The image processing operation is performed when the ENL signal is
low.
The image data of the (1024 pixels each) main scan line is divided into
4 blocks.

4. The image signal for the preheat is sent to the thermal control twice.
The first image signal responds to the first half of ENL low signal , and
the second image signal responds to the later half of ENL low signal.

2-49

28 February ’91

2.10.5 Temperature Rise Detection of Thermal Head/Power Supply:

A thermistor located on the thermal head and a thermal guard located on
the power supply board are used for thermal protection. This is to prevent
the temperature of the thermal head and the power supply board from
overheating when continuously processing a solid image.

1). Thermal head detecting temp. 54°C

2). Thermal head return temp. 50°C

3). Power supply detecting temp. 85°C

When the thermistor is open, a detection signal is applied.

Themal
Head
Drive

5V

CN702-13

CN404-13

+5V

Thermistor

Thermal Head

Thermal Guard

PSU

CN702-11

CN702-20

CN404-11

CN404-11

CN401-11

Image Processing

CN402-11

SIG: thermistor

Main Board

1). The thermal head temperature detection signal is applied if CN404-11
becomes greater than 3.13 volts (thermal head detecting temp.-- 54oC).

NOTE: Thermal head temperature detection signal is applied if the thermis-

tor is open circuit.

2). The thermal head temperature return signal is applied when CN404-11
becomes 2.98 volts (Thermal head return temp.-- 50oC).

3). The thermal guard detection signal is applied if CN401-11 is 0 volt
(Power supply detecting temp.-- 85oC).

4). The thermal guard temperature return signal is applied when CN401-11
becomes 5 volts.

5). When the temperature rise signal is applied, CN402-11 goes HIGH.

2-50

28 February ’91

During the master making process, if the pulse width is out of standard,
CN702-20 goes low and an error signal is applied to CN402-11. The master
making stops and E-08 lights. The machine then stops after a master is
wrapped around the drum.

If the thermal head temperature is still out of standard after the master
making process, an error signal is applied to CN402-11. The machine stops
and E04 lights.

If the power supply unit temperature is out of standard, the machine stops
and E-04 or E-08 lights.

NOTE: During all processes other than the master making process, E-04

will light when the PSU temperature reaches 85o.
During the master making process, E-08 will light when the PSU
temperature reaches 85o.

2-51

28 February ’91

2.11 MAKE-UP MODE: VT2500 only

2.11.1 Overall Operation

Image
Processing
Circuit

BCD

Main Board

CN402-31
CN402-32
CN402-33
CN402-34
CN402-35
CN402-36
CN402-37
CN402-38
CN402-39
CN402-40
CN402-41
CN402-42
CN402-45

MTF
DATA

P.
DATA

S

4

Make Up
Mode

Make Up
Mode

Normal
Processing
Mode

Selector
4

Make
Up
Mode

Thermal Head

Closed/
Diagonal

Pattern 0
Pattern 1
Pattern 2
Pattern 3
Pattern 4
Pattern 5
Pattern 6

S

BCD 1
BCD 2
BCD 4
BCD 8

MTF DATA

M DATA

2/4 mm

Original Image Data

Command Sheet

Image Data

M. DATA 2

Image Processing Board

Reduction
Circuit

Pattern

Generator

Area
Processing
Memory

Selector

Image
Edit
Circuit

2 mm

4 mm

Edited Image Data

The command sheet is read twice as fast as the original. The command
data is converted in the A/D converter and is modulated in the image
processing circuit. The modulated command data is reduced to 1/64 and
stored in the area memory. The area memory stores the command sheet
area data as area solid fill data.

The image data read by CCD is also converted and is modulated. The
modulated image data, the stored command area data, and the background
pattern are edited in the editing circuit of the make up control board
according to the editing command.

The edited image data is sent to the thermal head control board through the
image processing board.

When the make-up mode is not selected, the modulated image data that
was sent to the make-up control board is returned to the image processing
board without any processing.

2-52

28 February ’91

2.11.2 Command Sheet Data Reduction

The designated line data read from the command sheet is reduced to 1/64
and stored in the memory as shown in the illustration.

8 pixels

8 pixels

Stored Data

If any pixel in each of the 8 x 8 pixel squares is black, the square is stored
as black data.

2.11.3 Designated Area Memory

Command Sheet Reading

Designated Area
Data

Solid Fill Operation

Frame Memory

Solid Fill Operation
In Opposite Direction

Memory Processing

Designated Area Memory

The designated area by the command sheet is stored in the memory as a
solid fill area data.

The designated area is read in two directions. One is from the leading edge
to the trailing edge and the other is from the trailing edge to the leading
edge.

2-53

28 February ’91

1). Solid Fill Operation (Closed Area)

How to decide whether pixel E data is black or white.

1. When pixel E is black, E is
black.

2. When the pixel C or F is black
and also the pixel D or G is
black, E is black.

3. In all other cases, E is white.

Sub
Scanning
Direction

NOTE: The above operation also

acts in the opposite direction.

2). Solid Fill Operation (Diagonal Line)

How to decide whether pixel E data is black or white.

1. When the pixels B and D are
black, Pixel E is black.

2. When the pixel E is black, the
pixel E is black.

3. In all other cases, the pixel E
is white.

Sub
Scanning
Direction

NOTE: The above operation also acts

in the opposite direction.

Scanning Direction

A B C

D E F

G H I

Scanning Direction

A B C

D E F

G H I

2-54

28 February ’91

2.11.4 Make-up Control Circuit

H: Background
L: Image

MTF. DATA

Modulated Image

Data

M. DATA 1
Image Data

Outline Image

Data

S

H: Background
L: Image

DM
Pattern
Generator

CMDATA

Solid
Fill
Data
Area
Processing

DM

F/F

D Q

Q

Selection Table

DM

Selector

D 13 (Fn16.26.56.66)

D 12 (Fn15.25.55.65)

D 11 (Fn14.24.54.64)
D 10 (Fn13.23.53.63)

D 9 (Fn12.22.52.62)

D8 (Fn11.21.51.61)
D7 (Fn7)

D6 (Fn6)

D5 (Fn5)

D4 (Fn4)

D3 (Fn3)

D2 (Fn2)
D1 (Fn1)
D0

A

B

C

G

W

Image
Edit Data

BCD1

BCD2

BCD4

BCD8

Make-up Selection

Terminal

Make-up

Input Signal

BCD 1 H L H L H L H L L H L H L H
BCD 2 H H L L H H L L H L L H H L
BCD 3 H L H H L L L L H H H L L L
BCD 4 H H H H H H H H L L L L L L

D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12 D13

11.21

12.22

No

OFF 1 2 3 4 5 6 7

.51.61

.52.62

13.23

.53.63

14.24

.54.64

15.25

.55.65

16.26

.56.66

The make-up control circuit on the image processing board edits the image
using the above logic circuit.
The modulated image data, the outline image data, the background pattern
data and the designated area data are processed simultaneously in the
image processing board.

When the operator inputs a make-up number, the main board sends a 4-bit
signal to the make-up control circuit.
The circuit selects the corresponding make-up selection terminal (D0~D13).
This determines the path that image edit data takes before being output at
the "W" terminal.

2-55

28 February ’91

Fn1: Save area

The image data is ANDed with
the designated area data in
command sheet and the edited
image data is output.

Fn2: Delete area

The image data is ANDed with
the inverted data of designated
area and the edited image data
is output.

Image data

(Original)

Image data

(Original)

Designated area data

(Command Sheet)

Inverted data of

designated area

(Command Sheet)

Fn3: Outline Image

Step 1:
The outline image data is
ANDed with the designated
area data and the edited image
data is output.

Step 2:
The Fn2 data is ORed with the
step 1 data and the edited im­age data is output.

Outline image data

Fn2 data

(Original)

Designated area data

(Command Sheet)

(Step 1)

(Step 2)

2-56

28 February ’91

Fn4: Screen Image

Step 1:
This image data is ANDed with
the designated area data and
the edited image data is output.

Step 2:

1/4 mm

The screen pattern data is
ANDed with the step 1 data
and the edited image data is
output.

Step 3:
The Fn3 (step 1) data is ORed
with the step 1 data and also
ORed with the Fn2 data, and
the edited image data is output.

Fn5: Photo Image

Screen pattern data

1/4 mm

Fn3 (Step 1) data

Image data

(Original)

(Step 2)

Disignated area data

(Command Sheet)

(Step 1)

Fn2 data

(Step 3)

The designated area is processed by the photo mode processing.
The non designated area is processed by the line mode processing.
Above processing is performed independent of the image mode selection
on the operation panel.

Fn6: Save area and Outline image

Outline image data

(Original)

Designated area data
(Command Sheet)

The outline image data is
ANDed with the designated
area data and the edited image
data is output.

Screen

Fn7: Save area screen image

Step 1:

pattern data

1/4 mm

Fn1 data

1/4 mm

The screen pattern data is
ANDed with the Fn1 data and
the edited image data is output.

Step 2:

Fn3 (Step 1) data

(Step 1)

The Fn3 (step 1) data is ORed
with the step 1 data and the ed­ited image data is output.

2-57

(Step 2)

28 February ’91

Fn11, Fn21: Pattern Area / Outline Image
(Fn51, Fn62)
Fn14, Fn24: Save Area / Pattern Area /
(Fn54, Fn64)Outline Image

Step 1:
The background pattern data is
ANDed with the designated

Inverted image data

(Original)

area data and the edited image
data is output.

Step 2:
The inverted image data is
ANDed with the step 1 data
and the edited image data is
output.

Step 3:

Fn2 data

The step 2 data is ORed with
the Fn6 data and the edited im­age data is output.

Step 4:
The Fn2 data is ORed with the
step 3 data and the edited im­age data is output.

Background

pattern data

(Step 2) Fn6 data

(Step 4)

(Fn11, Fn21)

Designated area data

(Command sheet)

(Step 1)

(Step 3)

(Fn14, Fn24)

Fn 12, Fn22: Pattern Area / Normal
(Fn52, Fn62)Image
Fn 15, Fn25: Save Area / Pattern Area /
(Fn55, Fn65)Normal Image

Step 1:
The background pattern data is
ORed with the Fn1 data and
the edited image data is output.

Step 2:
The Fn2 data is ORed with the
step 1 data and the edited im­age data is output.

2-58

Background
pattern data

Fn2 data

(Fn12, Fn22)

Fn1 data

(Step 1)

(Fn15, Fn25)

(Step 2)

28 February ’91

Fn13, Fn23 : Pattern Image
(Fn53, Fn63)
Fn16, Fn26 : Save Area / Pattern Image
(Fn56, Fn66)

Step 1:
The image data is ANDed with

Fn6 data

the designated area pattern
data and the edited image data
is output.

Step 2:
The Fn6 data is ORed with the
step 1 data and the edited im­age data is output.

Step 3:
The step 2 data is ORed with

(Fn16, Fn26)

the Fn2 data and the edited im­age data is output.

Image data

(Original)

(Step 2)

Designated area

pattern data

(Step 1)

Fn2 data

(Step 3)

(Fn13, Fn23)

2-59

28 February ’91

2.11.5 Background Pattern

1). 4 mm Background Pattern

The 2mm background pattern data is stored in the ROM on the make-up
board.
The 4 mm background pattern is made by simply doubling the 2 mm
background data with the F/F circuit.

Background data in ROM

(2 mm standard pattern)

2/16

Paper

Feed

Direction

4 mm Background Pattern

2/16

2). 90o Pattern Rotation

The 90o 2 mm background pattern data is also stored in the ROM on the
make-up board.
The 90o 4 mm background pattern is made by doubling the 90o 2 mm
background pattern data that has been rotated 90o.

Background data in ROM

(2 mm standard pattern)

90o rotated background data in ROM

(90o 2mm rotated pat-

Paper

Feed

Direction

2/16

2-60

3). Background Patterns

The 40 background patterns shown below can be selected.

28 February ’91

1

4

2 3

5

6

7 8 9

2-61

28 February ’91

10

13

11 12

14

15

16 17 18

2-62

28 February ’91

19

22

20

23

21

24

25 26 27

2-63

28 February ’91

28

31

29 30

32

33

34 35 36

2-64

28 February ’91

37

40

38 39

2-65

28 February ’91

2.11.6 Recognition of Designated Area: VT2500 only

As the required image may differ depending on how the designated area is
entered, make the command sheet by referring to the following.

No. Item

1 Form of the

designated
area

Sample of Problem
Designated area Area recognized
Serial pattern The designated

area is
recognized as
follows:

Double circle
pattern.

Only the outer
circle will be
recognized as
follows:

Preferred designated area

Separation the area to be
designated as follows:

Make a space
more than 2
mm.

Make a space
more than 2
mm.

Designate area
by a closed line.

Make a gap in the pattern.

2 Non-closed

line

The designated
area is not a
closed loop.

The designated
area is not
recognized.

Designate the area by a closed
loop.

2-66

28 February ’91

No. Item

3 Thickness of

the
designating
line.

4 Density of

the
designated
line.

5 Type of

command
sheet.

Sample of Problem
Designated area Area recognized
The thickness

of the line as
follows:

X = Full Size:
less than 0.5
mm Reduction:
less than 0.7
mm

When using a
pencil with low
reflectivity or a
color pen.

1) Rough paper
is used as a
command sheet.

2) If the
command
sheet has a
different friction
coefficient from
the original.

X

As the line of
the designated
area is too thin,
no designated
area is
recognized.

As the
designating line
is too light, no
designated
area is
recognized.

Any fibrous
black spots will
be read as a
designated
area.

Due to different
registration of
the original and
the command
sheet, the
designated
areas vary.

Preferred designated area

Mark with a line more than 1 mm
in width.

Mark using a black pen.

Use white paper (65 g/m2).

Use white paper (65 g/m2).

2-67

28 February ’91

No. Item

6 Gap between

the
designated
area and
neighboring
image. (Gap
between two
designated
areas.)

Sample of Problem
Designated area Area recognized
When the gap

between the
designated
area and
neighboring
image is too
small.

Depending on
the original
feed condition
(registration
and skewing)
or handwriting
ability the
designated
area, the
neighboring
image may or
may not be
recognized as
a designated
area.

Preferred designated area

2 mm
2 mm

2 mm

1) There should be more than 2
mm clearance between
designated areas.

2) Mark the line away from the
image in the designated area
move than 2 mm to recognized
the image completely.

3) For consideration of the
handwriting ability, approximately
5 mm is needed as a gap.

2 mm

(Image in the designated area)

2-68

3. MASTER FEED SECTION

3.1 OVERALL

28 February ’91

[C]

[A]

[B]

[D]

The thermal head [A] burns an image on the master [B] as it is being fed to
the drum [C]. After this, the master is clamped and wrapped around the
drum.

2-69

28 February ’91

3.2 MASTER CLAMPER OPENING MECHANISM

[A]

[B]

[C]

[F]

[H]

[D]

[E]

[G]

After the master eject process is finished and the interrupter [A] is posi­tioned in the first drum position sensor [B], the main motor turns on and the
drum starts rotating (30 rpm) in the reverse direction.

When the drum turns 160 degrees past the actuation position of the second
drum position sensor [C], the cam [D] is moved to the drum’s side as the
master feed clamper solenoid [E] turns on.

When the drum turns 220 degrees further in the reverse direction, the sec­tor gear [F] runs along the cam [D] and the gear [G] turns counterclockwise
to open the clamper [H]. At the same time, the drum stops and the clamper
remains open to clamp the master leading edge.

2-70

3.3 MASTER FEEDING MECHANISM

[C]

28 February ’91

[A]

[M]

[J]

[I]

[N]

[K]

[L]

[E]

[P]

[G]

[D]

[F]

[H]

[O]

[B]

The original transport motor starts rotating after the drum rotates 120 de­grees past the 2nd drum position sensor. The reverse roller solenoid [A]
and the master feed motor [B] turn on after the original is fed 14 mm. The
rotation of the master feed motor is transmitted to the platen roller [C]
through the belt [D] and the pulley [E] which feeds the master and forces
the master to contact the thermal head [F]. Also, the rotation of the pulley
[E] is transmitted to the pulley [G] through the belt [H] to drive the upper
feed roller [I] and the lower feed roller [J] for master feeding.

[Q]

The spring clutch [K] is located behind the reverse roller [L]. When the re­verse roller solenoid turns on, the rotation of the upper feed roller is trans­mitted to the reverse roller through the belt [M] as the stopper [N] releases
the spring clutch, thus feeding the master. Also, the master is directed down
to the clamper [O] of the drum. The counter rollers [P] prevent the master
leading edge from being wrapped around the reverse roller.

After the master is fed 61 millimeters, the master feed clamper solenoid
turns off because the master leading edge has already reached the clam­per. At the same time, the reverse roller solenoid turns off and the reverse
roller stops.

A leaf spring on both holders [Q] prevents any master buckle due to free ro­tation of the master roll.

2-71

28 February ’91

3.4 MASTER WRAPPING MECHANISM

Sensor OFF: Sensor ON:

[D]

[C]

[B]

[A]

[B]

[F]

[E]

[F]

[B]

[E]

[F]

[E]

When the reverse roller solenoid [A] is turned off, the reverse roller [B]
stops as the stopper [C] locks the clutch gear [D].

However, since the feed roller [E] turn continuously, the master continues to
be fed causing the master to buckle. This buckle is detected by the master
buckle sensor [F]. When the sensor turns on, the main motor turns on at 10
rpm to rotate the drum. The main motor turns off when the sensor turns off.

Therefore, the master is fed by the ON/OFF action of the master buckle sen­sor.

2-72

3.5 CUTTER MECHANISM

[H]

[C]

[D]

[B]

28 February ’91

[A]

[G]

[E]

[F]

[I]

After the master making process (writing process) is finished, the master
feed motor turns off and the cutter motor [A] starts turning in the reverse di­rection as indicated by the arrow.

The cutter motor drives the wire pulley [B] through the gears [C], [D], [E],
and [F]. This is to shift the cutter unit to the rear (non-operation side). As
the cutter [G] rotates and travels to the rear, it cuts the master.

When the right cutter switch [H] turns on, the cutter motor starts turning in
the opposite direction to return the cutter unit to the front (operation side).
When the left cutter switch [I] turns on, the cutter motor stops. This finishes
the master cutting process.

After the master cutting process is finished, the master is fed about 42 milli­meters.

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