Seiko LTP1245R-C384-E, LTP1245S-C384-E, LTP1245T-S384-E, LTP1245U-C384-E Technical Reference

LTP1245X-X384-E

LINE THERMAL PRINTER MECHANISM

TECHNICAL REFERENCE

U00085320001

Seiko Instruments Inc.

LTP1245X-X384-E LINE THERMAL PRINTER MECHANISM TECHNICAL REFERENCE

Document Number U00085320001

First Edition December 2003
Second Edition March 2005

Copyright © 2003, 2005 by Seiko Instruments Inc.

All rights reserved.

Seiko Instruments Inc. (SII) has prepared this manual for use by SII personnel, licensees, and customers.
The information contained herein is the property of SII and shall not be reproduced in whole or in part without
the prior written approval of SII.

SII reserves the right to make changes without notice to the specifications and materials contained herein
and shall not be responsible for any damages (including consequential) caused by reliance on the materials
presented, including but not limited to typographical, arithmetic, or listing errors.

SII is a trademark of Seiko Instruments Inc.

PREFACE

This reference manual describes the specifications and basic operating procedures for the LTP1245 (for
RoHS) Line Thermal Printer Mechanism.

For the LTP1245 (RoHS supporting), four models are available:

• LTP1245R-C384-E

• LTP1245S-C384-E

• LTP1245T-S384-E

• LTP1245U-S384-E

In this reference manual, the information mentioned as LTP1245 is common to all models

unless otherwise noted, and if the information is different depending on the model, specific

model name is mentioned clearly.

Chapter 1 “Precautions” describes safety, design and operational precautions. Read it thoroughly before
designing so that you are able to use the LTP1245 properly.

SII has not investigated the intellectual property rights of the sample circuits included in this manual. Fully
investigate the intellectual property rights of these circuits before using.

Also, when designing the circuits based on the sample circuits in this reference manual, use them after
thorough verification.

iii

iv

TABLE OF CONTENTS

Section Page

CHAPTER 1 PRECAUTIONS

1.1 SAFETY PRECAUTIONS ............................................................................................ 1-1

1.2 DESIGN AND HANDLING PRECAUTIONS................................................................ 1-2

1.2.1 Design Precautions......................................................................................... 1-2

1.2.2 Handling Precautions...................................................................................... 1-3

1.2.3 Precautions on Discarding .............................................................................. 1-4

CHAPTER 2 FEATURES

CHAPTER 3 SPECIFICATIONS

3.1 GENERAL SPECIFICATIONS..................................................................................... 3-1

3.2 HEAT ELEMENT DIMENSIONS.................................................................................. 3-3

3.3 PAPER FEED CHARACTERISTICS............................................................................ 3-4

3.4 STEP MOTOR CHARACTERISTICS........................................................................... 3-5

3.4.1 Motor Drive Circuit........................................................................................... 3-6

3.4.2 Motor Timing.................................................................................................... 3-8

3.4.3 Precautions for Driving the Motor.................................................................... 3-10

3.5 THERMAL HEAD ......................................................................................................... 3-14

3.5.1 Structure of the Thermal Head........................................................................ 3-14

3.5.2 Printed Position of the Data............................................................................. 3-16

3.5.3 Head Resistance............................................................................................. 3-17

3.5.4 Head Voltage................................................................................................... 3-17

3.5.5 Peak Current ................................................................................................... 3-17

3.5.6 Thermal Head Electrical Characteristics......................................................... 3-18

3.5.7 Timing Chart.................................................................................................... 3-19

3.6 CONTROLLING THE HEAD ACTIVATION (DST) PULSE WIDTH............................. 3-20

3.6.1 Calculation of the Head Activation Pulse Width.............................................. 3-20

3.6.2 Calculation of the Applied Energy................................................................... 3-20

3.6.3 Adjustment of the Head Activation Voltage..................................................... 3-21

3.6.4 Adjustment of the Head Resistance................................................................ 3-21

3.6.5 Determination of Activation Pause Time and Activation Pulse Period............ 3-22

3.6.6 Head Activation Pulse Term Coefficient.......................................................... 3-22

3.6.7 Calculation Sample for the Head Activation Pulse Width ............................... 3-23

3.6.8 Thermistor Resistance .................................................................................... 3-24

3.6.9 How to Print Using 2-ply Thermal Paper......................................................... 3-25

3.6.10 Detecting Abnormal Temperatures of the Thermal Head............................... 3-26

3.7 HEAD-UP/PAPER DETECTOR................................................................................... 3-27

3.7.1 General Specifications .................................................................................... 3-27

3.7.2 Sample External Circuit................................................................................... 3-28

3.7.3 Automatic Paper Load..................................................................................... 3-29

3.8 Mode Code Label......................................................................................................... 3-30

v

Section Page

CHAPTER 4 CONNECTING EXTERNAL CIRCUITS

4.1 THERMAL HEAD CONTROL TERMINALS................................................................. 4-2

4.2 MOTOR AND DETECTOR TERMINALS..................................................................... 4-3

CHAPTER 5 DRIVE METHOD

5.1 THERMAL HEAD DRIVE TIMING................................................................................ 5-1

5.2 MOTOR DRIVE TIMING .............................................................................................. 5-2

CHAPTER 6 HOUSING DESIGN GUIDE

6.1 SECURING THE PRINTER ......................................................................................... 6-1

6.1.1 Printer Mounting Method................................................................................. 6-1

6.1.2 Precautions for Securing the Printer............................................................... 6-1

6.2 LAYOUT OF PRINTER AND PAPER .......................................................................... 6-2

6.3 WHERE TO MOUNT THE PAPER HOLDER.............................................................. 6-2

6.4 WHERE TO MOUNT THE PAPER CUTTER............................................................... 6-2

6.5 OUTER CASING STRUCTURE................................................................................... 6-3

CHAPTER 7 APPEARANCE AND DIMENSIONS

CHAPTER 8 LOADING/UNLOADING PAPER AND HEAD CLEANING

8.1 LOADING/UNLOADING PAPER PRECAUTIONS ...................................................... 8-1

8.2 HEAD CLEANING PROCEDURE AND PRECAUTIONS............................................ 8-3

CHAPTER 9 PERIPHERAL EQUIPMENT

9.1 AUTOCUTTER UNIT ................................................................................................... 9-1

9.1.1 Installation........................................................................................................ 9-2

9.1.2 Opening and Closing the Autocutter Unit........................................................ 9-3

9.1.3 Inserting Recording Paper .............................................................................. 9-4

9.1.4 Clearing Paper Jams....................................................................................... 9-4

9.1.5 Hints for Use.................................................................................................... 9-5

9.1.6 External View when the LTP1245 is equipped with the Autocutter................. 9-6

9.2 LTP1245 MOUNT (OP-L1245A-E)............................................................................... 9-7

9.2.1 Installation........................................................................................................ 9-7

9.2.2 OP-L1245A-E External View........................................................................... 9-8

vi

FIGURES

Figure Page

3-1 Heat Element Dimensions............................................................................................ 3-3

3-2 Print Area...................................................................................................................... 3-3

3-3 Sample Drive Circuit (Motor)........................................................................................ 3-6

3-4 Input Voltage Signals for the Sample Drive Circuit (Motor)......................................... 3-7

3-5 Motor Start/Stop Timing (Sample Drive Circuit (Motor) )............................................. 3-8

3-6 Motor Drive Timing Chart (in use at temperature over -5°C)....................................... 3-10

3-7 Motor Drive Timing Chart (in use at temperature below -5°C)..................................... 3-11

3-8 Thermal Head Block Diagram...................................................................................... 3-15

3-9 Printed Position of the Data.......................................................................................... 3-16

3-10 Timing Chart................................................................................................................. 3-19

3-11 Thermistor Resistance vs. Temperature...................................................................... 3-24

3-12 How to Drive 2-ply Thermal Paper............................................................................... 3-25

3-13 Sample External Circuit of the Head-Up/Paper Detector............................................. 3-28

3-14 Flowchart for Automatic Paper Load............................................................................ 3-29

3-15 Model Code Label ........................................................................................................ 3-30

4-1 Thermal Head Control Terminals (FFC)....................................................................... 4-2

4-2 Motor and Detector Terminals (FPC)........................................................................... 4-3

5-1 Example of Timing Chart of the Thermal Head Driving ............................................... 5-1

5-2 Example of Motor Drive Timing Chart.......................................................................... 5-4

6-1 Paper Layout................................................................................................................ 6-2

6-2 Sample Outer Casing Structure................................................................................... 6-3

7-1 LTP1245R-C384-E Appearance and Dimensions....................................................... 7-2

7-2 LTP1245S-C384-E Appearance and Dimensions ....................................................... 7-3

7-3 LTP1245T-C384-E Appearance and Dimensions........................................................ 7-4

7-4 LTP1245U-C384-E Appearance and Dimensions....................................................... 7-5

8-1 Head Cleaning Procedure............................................................................................ 8-3

9-1 Installation .................................................................................................................... 9-2

9-2 Designing a Mount ....................................................................................................... 9-

9-3 Opening and Closing of Autocutter Unit....................................................................... 9-3

9-4 Head-up Lever Position................................................................................................ 9-3

9-5 Best Cutting Position for Efficient Paper Use............................................................... 9-5

9-6 External View when the LTP1245 is equipped with the Autocutter ............................. 9-6

9-7 LTP1245 Mount Installation.......................................................................................... 9-7

9-8 LTP1245 Mount External View (OP-L1245A-E)........................................................... 9-8

3

vii

TABLES

Table Page

3-1 General Specifications ................................................................................................. 3-1

3-2 Sample Motor Drive Frequency................................................................................... 3-4

3-3 General Motor Specifications....................................................................................... 3-5

3-4 Excitation Sequence..................................................................................................... 3-7

3-5 Acceleration Steps ....................................................................................................... 3-13

3-6 Blocks and Activated Heat Elements........................................................................... 3-16

3-7 Head Voltage................................................................................................................ 3-17

3-8 Thermal Head Electrical Characteristics...................................................................... 3-18

3-9 Activation Pulse Width.................................................................................................. 3-23

3-10 Temperature and Corresponding Thermistor Resistance............................................ 3-25

3-11 Detector's Status and Output Signals .......................................................................... 3-27

3-12 Absolute Maximum Ratings of Detectors..................................................................... 3-27

3-13 Detectors Input / Output Conditions............................................................................. 3-28

4-1 Recommended Connectors ......................................................................................... 4-1

4-2 Thermal Head Control Terminal Assignments............................................................. 4-2

4-3 Motor and Detector Terminals Assignments................................................................ 4-3

viii

CHAPTER

PRECAUTIONS

Read through this manual to use the printer properly.
Also, design the product taking the detailed precautions that are noted in each section into consideration.

 This reference manual subjects to change without notice.

Ask the latest information of the printer to our service.

 Damage due to improper handing of the printer without following the instruction described in this

reference manual will not be responsible for SII.

 To use the printer safely, design the product taking the precautions described below into

consideration.
Also, attach the safety precautions to all of user's manuals to further inform the users
concerning usage safety.

1.1 SAFETY PRECAUTIONS

To use the printer safely, design the product taking the precautions described below into consideration.
Also, attach the safety precautions to all of user’s manuals, as well as place warning labels on the products
to further inform the users concerning usage safety.

 Precautions to prevent the thermal head from overheating

If the thermal head heat element, which always has electricity supplied by the CPU,
malfunctions, the thermal head may overheat, causing smoke and fire.
To prevent personal injury, the printer should be controlled so that the detection of abnormal
temperatures of the thermal head is performed as described in Section 3.6.9.
Turn printer off immediately if abnormal conditions occur.

 Precautions on temperature of the thermal head when handling

Design the outer case to prevent the user from being burnt by touching the thermal head and its
periphery directly due to the fact that the thermal head and its periphery are hot when printing
and remains so immediately after printing. Regarding paper insertion and head cleaning,
prepare caution descriptions in the manual stating to perform these operations after the head
temperature drops. To allow cooling, insert clearance between the head and the outer case in
designing the outer case.

 Precautions regarding raising the temperatures of the motor

Give warning to prevent the user from being burnt by touching the thermal head directly due to
the fact that the motor is hot when operated and remains so immediately after operating. To
allow cooling, insert clearance between the head and the outer case in designing the outer
case.

 Precautions regarding sharp edges of the printer body

The printer body and/or some parts may have some sharp edges. Design the outer case to
prevent the user from being injured by touching said sharp edges and provide warnings
concerning this.

1

1-1

1.2 DESIGN AND HANDLING PRECAUTIONS

To maintain the initial level of performance of the LTP1245 and to prevent future problems from occurring,
observe the following precautions.

1.2.1 Design Precautions

 If too much energy is applied to the thermal head, it may overheat and become damaged.

Always use the printer with the specified amount of energy.

Do not input a pulse over than 2V and 20 nsec to each signal terminal of the thermal head.

 Use C-MOS IC chips (74HC240 or equivalent) for CLK, LATCH, DAT and DST signals of the

thermal head.

 When turning the power on or off, always DISABLE (put in “Low” state) the DST terminals.

 To prevent the thermal head from being damaged by static electricity:

• Fix the printer to the Frame Ground (FG) by the FG connection parts as shown in Figure
7-1.

• Connect the GND terminal (SG) to FG through an approximate 1 MΩ resister.

 Keep the Vp power off when not printing in order to prevent the thermal head from becoming

electrically corroded.
In addition, design the printer so that the signal GND of the thermal head and the frame GND of
the printer mechanism become the same electric potential.

 Make the wire resistance between the power supply and the Vp as well as GND terminals on the

thermal head controller as small as possible (below 50 mΩ). Maintain a considerable distance
from signal lines to reduce electrical interference.

 Surge voltage between Vp and GND should not exceed 10 V.

 As a noise countermeasure, connect the capacitor noted below between Vdd and GND pins

near the thermal head control connector.

Vp ↔ GND: approximately 10 µF
Vdd ↔ GND: approximately 1 µF

 Turn on power in the following manner:

At power ON: 1) Vdd (5 V) → 2) Vp
At shut down: 1) Vp → 2) Vdd (5 V)

 Always detect the outputs of the head up detectors and paper detectors. Incorrect activation of

the thermal head may reduce its longevity and the platen, and damage the thermal head and
the platen.

 To prevent malfunction of the detector, design the printer so that the infrared ray is not input

around the head up detector.

1-2

 Design the outer case so that the thermal head control terminals can move after fixing to the

connector because they move 2 to 3 mm due to the up/down action of the thermal head.

 Design the outer case so that it prevents the paper feed out from being caught in the platen.

 If the thermal head remains in contact directly with the platen, they may stick tight each other.

When the printer is not in use, put the paper between the thermal head and platen or place the
thermal head in an upward position. If the thermal head and the platen stick tight, it is only
necessary to release the thermal head so that the problem can be avoid.

 Design software that will deactivate the heat elements if the thermal head thermistor (TH)

detects a temperature higher than 80 °C (thermistor resistance RTH ≤ 2.48 kΩ), and reactivate
the heat elements when a temperature lower than 60 °C (RTH ≥ 4.46 kΩ) is detected. If the
thermal head continues to be activated at a temperature higher than 80 °C, the life of the
thermal head may be shortened significantly.

 The cutting surface of the motor flange may generate discoloration and rust according to

operating condition.
This is no problem for functions, however, take it into external view consideration.

1.2.2 Handling Precautions

Incorrect handling may reduce the efficiency of the printer and cause damage. Handle the printer with the
following precautions.
Also, get an operator’s attention.

 To prevent the heat elements, ICs, etc. from being damaged due to static electricity, take

measures against electrification for both machine and human before handling the printer.
Care should be taken in particular regarding the thermal head control terminals when handling.

 Do not apply stress to the thermal head control terminals; otherwise connectors, FPC (Flexible

Printed Cable) and FFC (Flexible Flat Cable) for the thermal head may be damaged.

 If any paper other than that specified is used, a high print quality and longevity of the thermal

head cannot be guaranteed.

Possible problems that may occur are:

• Poor printing quality due to low-sensitive paper

• Abrasion of the thermal head due to a paper surface which is too rough

• Sticking between the thermal layer of the paper and the thermal head resulting in

excessive noise when printing

• Print fading due to low print preservation

• Corroded thermal head due to poor thermal layer of the paper.

 Do not activate without paper; otherwise, the platen or thermal head may become damaged.

 Do not hit or scratch the surface of the thermal head with sharp or hard objects. It may become

a source of damage to the heat element.

 The thermal head is pressurized at the time of delivery from the factory. Place the thermal head

in an upward position before use. The head down, neutral and head up positions can be set
with the head up/down lever.

1-3

 Connect or remove the connectors after powering off the printer.

 When printing at a high print rate (black or zigzag pattern) in a low temperature or high humidity

environment, the vapor from the paper during printing may cause condensation to form on the
printer or may soil the paper itself.

Keep the thermal head away from water drops.
It may become the source of a corroded thermal head.
If condensed, power off the Vp until dried.

 The LTP1245 is not a water-proof printer. Prevent contact with water and do not perform

operations with wet hands. They may become sources of damages to short circuits,

overheating and fire.

 The LTP1245 is not a dust-proof printer. Use in a dusty place may cause damage to the

thermal head and cause paper feed problems.

1.2.3 Precautions on Discarding

When discarding used printers, discard them according to disposal regulations and rules of each
respective district.

1-4

CHAPTER

2

FEATURES

The LTP1245 Line Thermal Printer Mechanism is a compact, high-speed thermal line dot printing
mechanism. It can be used with a measuring instrument and analyzer, a POS, a communication device,
or a data terminal device.

Since the LTP1245 Line Thermal Printer Mechanism can be battery driven, it can easily be mounted onto
a portable device such as a hand-held terminal.

The LTP1245 has the following features:

 Uses a 5 V power supply or battery power supply
The voltage used to drive the thermal head is equal to the logic voltage, or is driven by a 5 V

single power line.

The range of operating voltage is wide, so four to six Ni-Cd batteries or Ni-MH batteries can also

be used. Two Lithium-ion batteries can be used.

 Compact and light
The mechanism is compact and light: 72 mm in width, 39.5 mm in depth, 16 mm in height, and

approximately 45 g in weight.

 High resolution printing
A high-density print head of 8 dots/mm produces clear and precise printing.

 Longevity
The mechanism is a maintenance-free device with a long life of 50 km print length and/or 100

million pulses. (Coupling with recommended thermal paper.)

 High speed printing

1

A maximum print speed of 200 dot lines per second (25 mm per second) at 5 V, 450 dot lines

per second (56.25 mm per second) at 7.2 V, and 500 dot lines per second (62.5 mm per
second) at 8.0 V is attainable.

 Low current consumption
The printer can be driven on low discharge current lithium-ion batteries.

 Paper loading path

2

Two systems of paper loading path are provided, curl path and straight path, and the straight

path allows thick paper to be printed.

 Low noise
Thermal line dot printing is used to guarantee low-noise printing.

2-1

 Automatic paper load

The paper detector enables the LTP1245 to load paper automatically.

 Paper feed knob

2

The paper feed knob for manual paper feed is optionally attached depending on the

specification. It is selectable according to the applications.

 Thermal head cleaning
Move the head up lever to open position to clean the thermal head.

1

Print speed differs depending on working and environmental conditions.

2

The paper loading paths (curl path and straight path) and the presence of paper feed knob

are optionally set in the factory.

Please consult our sales representative when ordering them.

2-2

CHAPTER

3

SPECIFICATIONS

3.1 GENERAL SPECIFICATIONS

Table 3-1 General Specifications

Item Specification

Print method Thermal dot line printing
Dots per line 384 dots
Resolution 8 dots/mm
Print width 48 mm
Maximum printing speed 200 dot lines/s (25.0 mm/s) (at 5 V)

Paper feed pitch 0.125 mm
Head temperature detection Via thermistor
Head-up detection Via photo interrupter
Out-of-paper detection Via photo interrupter
Operating voltage range
V

V
Current consumption
For driving the head (V

For driving the motor (V
For head logic (V

line (for head and motor drive)

P

line (for head logic)

dd

)

P

)

P

)

dd

450 dot lines/s (56.25 mm/s) (at 7.2 V)
500 dot lines/s (62.5 mm/s) (at 8.0 V)

4.2 V to 8.5 V

2

(equivalent to four through six Ni-Cd or Ni-MH
batteries, or two lithium-ion batteries)

4.5 V to 5.5 V

Average:

1.5 A (at 5 V), 2.2 A (at 7.2 V), 2.6 A (at 8.5 V)
Maximum:

1.6 A (at 5 V), 2.3 A (at 7.2 V), 2.7 A (at 8.5 V)
Maximum 0.46 A
Maximum 0.01 A

1

1

1

3

3

3-1

Table 3-1 General Specifications (Continued)



Item Specification

Operating temperature range

-30°C to 70°C 4
(No codensation)
Storage temperature range

-35°C to 75°C
(No codensation)
Life span (at 25°C and rated energy)
Activation pulse resistance
Abrasion resistance

100 million pulses or more (print ratio=12.5%)

5

50 km or more (excluding damage due to an alien
substance such as rubbish)

Paper width 58 mm

0

-1



Paper feeding force 0.49 N (50 gf) or more
Paper holding force 0.78 N (80 gf) or more
Dimensions (width×depth×height) 72 × 39.5 × 16 mm (excluding head up lever)
Weight Approximately 45 g
Recommended thermal paper

6

-5°C to 50°C

• TF50KS-E2D (Normal thermal paper）
from Nippon Paper Industries

• AF50KS-E (Normal thermal paper）
from Jujo thermal Ltd.

• KT55F20 (Normal thermal paper）
from Koehler AG

• F5041 (Normal thermal paper
from

Mitsubishi Hitec Paper

• TL69KS-HG76 (label paper)

7

from Nippon Paper Industries

-30°C to 70°C

• TL51KS-R2 (High heat-resistant paper)
from Nippon Paper Industries

• TL69KS-R2 (High heat-resistant paper)
from Nippon Paper Industries

5°C to 40°C

• TW80KK-S (2-ply thermal paper)

5, 7

from Nippon Paper Industries

1

The maximum printing speed is attained, for example, in the following case:

Driving voltage 8.0V, head temperature over 10°C, and simultaneously activated dot number within 64 dots

2

At the operating temperature below -5°C, the printing of 7.0V or less (Vp) becomes light.

3

Given when simultaneously activated dot number is 64 dots during head driving.

4

Do not perform continuous printing for more than 5 minutes at the temperature over 50°C.

In out of temperature range -5 to 50°C, drive the head in the fixed 2-division driving mode.
At the temperature below -20°C, thermal agent may attach to the head. In such a case, clean the head.

5

In the case of thermal copying paper, the printing is executed in the 2 pulses/1 dot mode, and therefore the printing

corresponds to 50 million dots line.

6

If printing in other than this range, the printing may blur or become light.

7

Not be used in a curled path (LTP1245R, S).

3-2

3.2 HEAT ELEMENT DIMENSIONS

The LTP1245 contains a thermal head with 384 heat elements (dot-size).

48 mm (384 DOTS)

0.125 mm

0.125 mm

Figure 3-1 Heat Element Dimensions

5 mm

0

58 mm (PAPER WIDTH)

-1

48 mm (PRINTING WIDTH)

5 mm

0.125 mm

(PAPER

FEED

PITCH)

Figure 3-2 Print Area

3-3

3.3 PAPER FEED CHARACTERISTICS

 Paper is fed in a forward direction when the motor shaft is rotating in the normal direction

(clockwise) when seen from the motor gear side.

 The motor is driven by a 2-2 phase excitation, constant current chopper method and feeds paper

by 0.125 mm (equivalent to a single dot pitch) every two steps of the motor drive signal.

 To prevent deterioration in printing quality due to backlash of the paper feed system, the motor

should be driven 40 steps in a reverse direction then 40 steps in the normal direction during
initialization or following backward feeding.

 During paper feeding, the motor should be driven lower than the value obtained by equation (1).

When at - 5°C or higher:

Equation (1):

Vp × 165 - 220 (pps) (max.1000 (pps) )

When at lower than 5°C:

300 (pps)

 During printing, motor drive frequency should be adjusted according to working conditions such as

voltage, temperature, number of activated dots, etc. (For details, see CHAPTER 5 DRIVE
METHOD.)

 Drive the motor at 200 pps when automatically loading paper, regardless of the voltage.

As for the motor current value, to keep the motor torque, activate the motor by only the first setting
current value (i.e. one current) for the entire motor drive step time. (See Chapter 3.4.3
Precautions for Driving the Motor.)

 It is not possible to print while the motor is rotating in a reverse direction.

Table 3-2 Sample Motor Drive Frequency

Operating

Voltage

4.2 V 473 pps 200 pps
5 V 605 pps 200 pps
6 V 770 pps 200 pps

7.2 V 968 pps 200 pps
8 V 1000 pps 200 pps

8.5 V 1000 pps 200 pps

Drive Frequency

when feeding paper

3-4

Drive Frequency

when automatically

loading paper

3.4 STEP MOTOR CHARACTERISTICS

Table 3-3 General Motor Specifications

Item Specification

Type PM
Number of phases 4-phase
Drive method Bipolar chopper
Excitation 2-2 phase
Winding resistance per phase 14 Ω ±10%
Rated voltage 4.2 - 8.5 V
Rated current 0.23 A/phase, 0.15 A/phase
Maximum current consumption 0.46 A
Drive frequency 50 - 1000 pps (according to drive voltage)

1

See 3.4.3 Precautions for Driving the Motor.

When at lower than - 5°C, the motor is driven at 0.23 A/phase only.

1

3-5

3.4.1 Motor Drive Circuit

4

1%

1%

3

11 20

16

20 11

6 1 15 14

12 12

3

19 6

Vp

18

2

12

(1) Sample Drive Circuit

Sample drive circuit for the motor are shown in Figure 3-3.

NC

9

1

13

14

LB1843V-E

10µF

0.51Ω
1%
1/2W

50V

15

5

3

74HC123A

9

LB1843V-E

19

7

6

10

Vcc

10KΩ

2

18

15

4

5

Vcc

3KΩ
1%

0.01µF
10%,10%

1KΩ
1%

0.51Ω
1%
1/2W

Vp

10µF
50V

Vcc

3KΩ
1%

0.01µF
10%,10%

0.01µF
10%,10%

6

A

7

B

8

A

9

B

PH1
PH2
PH3
PH4

CTCRL

0.1µF

Vcc

1SS294
(TE85L, F)

µPC1060C-A

1

74HC32

0.01µF
10%,10%

1.8KΩ
1%

2.7KΩ

2

0.1µF

3.3KΩ

1KΩ
1%

0.1µF

74HC32

NC

Vcc

10KΩ

Vcc

17

13
2

4

3
11

8

5

13

14

9
1

17

Figure 3-3 Sample Drive Circuit (Motor)

3-6

(2) Excitation Sequence

L

H

H

B

As shown in Table 3-4, the LTP1245 feeds paper in the normal direction when the motor is excited

in the order of step 1, step 2, step 3, step 4, step 1, step 2, . . . . On the other hand, to rotate the

motor in a reverse direction, drive the motor in the reverse order of: step 4, step 3, step 2, step 1,

step 4, step 3, . . . .

Table 3-4 Excitation Sequence

Signal Name Sequence

Step 1 Step 2 Step 3 Step 4

A Low High High Low
B High High Low Low
A High Low Low High
B Low Low High High

A

B

H

L

H

A

L

L

1 DOT LINE

Figure 3-4 Input Voltage Signals for the Sample Drive Circuit (Motor)

3-7

3.4.2 Motor Timing

H

H

PAUSE

STATE

Refer to the timing chart in Figures 3-5 and 3-6 when designing the control circuit or software for starting
and stopping the motor. Also take note of the following precautions:

Precautions for Designing the Motor Control Circuit and Software

(1) Stop step

 To stop the motor, excite for a single step period with a phase that is the same as the last one in

the printing step.

(2) Pause state

 In the pause state, do not excite the step motor in order to prevent the motor from heating. Even

when the step motor is not excited, it maintains a holding force to prevent paper from sliding.

(3) Start step

 To restart the motor from the stop step, immediately shift the motor into the printing sequence.

 To restart the motor from the pause (no excitation) state, shift the motor into the printing sequence

after outputting a phase that is the same as that of the stop step for a single step.

When using the Sample Drive Circuit (Motor) :

1 DOT LINE

PH1

L

H

PH2

L

H

PH3

L

PH4

L

STOP

STEP

START

STEP

PRINT STEP

PRINT STEP

Figure 3-5 Motor Start/Stop Timing (Sample Drive Circuit (Motor) )

3-8

(4) Others

 Do not print paper at the intermittent feed mode. Doing so may deteriorate the printing quality due

to irregular paper feeding pitch.

 To print characters and bit images, always follow the start step and stop step.

3-9

3.4.3 Precautions for Driving the Motor

CTCRL

PH1

PH2

PH3

PH4

(1) Motor Current Control

Low speed motor driving while printing due to a division drive method, print data, and input data transfer
speed may cause noise or print trouble to occur due to over torquing or overheating of the motor.
To prevent these from occurring, be sure to set the motor current as follows and perform two-current
control.

Activate the motor with the 1st setting current in each motor drive step.
Change the activation current to the 2nd setting current after activating the motor with the 1st setting
current for T1.
T1 is defined from each period of the motor drive step and Vp voltage as follows:

How to define T1 (unit: µµµµs)
When Vp is under 7.2 V :
T1: Compare the following two values and adopt the smaller one.

(Each period of the motor drive step - 500) and 925.9
When Vp is 7.2 V or more :
T1: Compare the following two values and adopt the smaller one.
(Each period of the motor drive step - 500) and (1000000 / (3600 - Vp × 350))

In use at temperature below -5°C, Control the 0.23(A) at 1st current.

T1 T1 T1 T1 T1

230mA

150mA

Start 1st step 2nd step 3rd step 4th step

(5.78ms)

Set the 1st setting current at CTCRL=“High”: 0.23 (A)

Set the 2nd setting current at CTCRL=“Low”: 0.15 (A)

(5.78ms) (3.57ms) (2.76ms) (2.31ms)

Figure 3-6 Motor Drive Timing Chart (in use at temperature over -5°°°°C)

3-10

In use at temperature below -5°C

CTCRL1

230mA

PH1

PH2

PH3

PH4

Start

(5.78ms)

Motor speed = 300 pps CTCRL1=”High” First set current: 0.23 (A)

1st step

(5.78ms)

2nd step
(3.57ms)

Figure 3-7 Motor Drive Timing Chart (in use at temperature below -5°°°°C)

3rd step

(3.33ms)

4th step

(3.33ms)

Max speed=300pps

5th step

(3.33ms)

6th step

(3.33ms)

3-11

(2) Acceleration Control

When driving the motor, acceleration control is needed to start paper feeding. When the motor is to be
driven at the motor drive frequency that is calculated using equation (1), the motor may come out of step
under heavy load.
Drive the motor to the maximum driving speed that is calculated using equation (1), according to the linear
acceleration table in Table 3-5.

The method for accelerating the motor is as follows:

1. Output start step (5780 (µs)).

2. Output first step for the first acceleration step time

3. Output second step for the second acceleration step time

4. Output n

th

step for the nth step acceleration time

5. After outputting the time calculated using equation (1), the motor is driven at a constant speed.

The printer can print during acceleration.
Set the maximum drive speed to 300 pps (3333 µs) for printing at lower than -5°C.
When accelerating it again after decreasing the speed, follow the method shown below.
When the step time is Tm (the reciprocal number of the frequency calculated using equation (1)),
compare Tm with the time that was taken in the previous step.

(1) In case Tm > time that was taken in the previous step (i.e. decreasing speed)

the closest acceleration step time to Tm and the acceleration step time that is larger thanTm, are
output.

(2) In case Tm < time that was taken in the previous step (i.e. reacceleration time)

the next closest acceleration step time to the previous step time or Tm, which is longer, is output.

3-12

Table 3-5 Acceleration Steps

Number of

Steps

start

1
2
3
4
5
6
7
8

9
10
11
12
13
14
15
16
17
18

Speed

(pps)

173
280
362
432
493
547
597
644
687
728
768
805
840
874
907
939
970

1000

Step Time

(µs)

5780
5780
3571
2762
2314
2028
1828
1675
1553
1456
1374
1302
1242
1191
1144
1103
1065
1031
1000

3-13

3.5 THERMAL HEAD

3.5.1 Structure of the Thermal Head

As Figure 3-8 shows, the LTP1245 thermal head consists of 384 heat elements, and heat element drivers.

Serial printing data input from the DAT terminal is transferred to the shift register synchronously with the
CLK signal, then stored in the latch register with the timing of the LATCH signal.

Inputting the head activation signal (DST 1 to 6) activates heat elements in accordance with the printing
data stored in the latch register.

A maximum of six division printing is available for the LTP1245.

Table 3-6 shows the relationship between DST signals and heat elements.

3-14

Block6 Block5 Block2 Block1

Vp

DAT

CLK

LATCH

DST6

DST5

Heat Element

Output Driver

Latch Register

Shift Register

DOT 384

DOT 321

DOT 320

DOT 257

DOT 256

DOT 129

DOT 128

DOT 64

DOT 65

DOT 1

DST2

DST1

TH

Thermistor

Vdd

GND

Figure 3-8 Thermal Head Block Diagram

3-15

Table 3-6 Blocks and Activated Heat Elements





Block Number Heat Element Number Dots / Block

1 1 - 64 64
2 65 - 128 64
3 129 - 192 64
4 193 - 256 64
5 257 - 320 64



6 321 - 384 64

3.5.2 Printed Position of the Data
Data dots from 1 to 384 which are transferred through DAT are printed as shown in Figure 3-9.




PAPER

PAPER FEED DIRECTION

PRINT SURFACE

DATA PRINT SEQUENCE

1 2 3 4 5 6 ............................. 382 383 384

LTP1245 PRINTER MECHANISM

DATA INPUT SEQUENCE 1 2 3 4 5 6 . . . . . . 382 383 384

DATA IN



Figure 3-9 Printed Position of the Data

3-16

3.5.3 Head Resistance

N

× Vp

The LTP1245 head resistance is176 Ω ± 4 %.

3.5.4 Head Voltage

The LTP1245 has a built-in head driver IC and control IC. Table 3-7 shows the head voltage.

Table 3-7 Head Voltage

Item Voltage Range

Head drive voltage Vp

Head logic voltage Vdd

3.5.5 Peak Current

Since the peak current (maximum current) may reach the values calculated using equation (2) when the
thermal head is driven, make sure that the allowable current for the cable material and the voltage drop on
the cables are well within the specified range.

Equation (2):

Ip: Peak current (A)
N: Number of dots that are driven at the same time
Vp: Head drive voltage (V)
RH: Head resistance (Ω)

Ip= 
RH

4.2 to 8.5 V

4.5 to 5.5 V

3-17

3.5.6 Thermal Head Electrical Characteristics

Table 3-8 Thermal Head Electrical Characteristics

(Vdd=4.5 to 5.5V, Ta=0 to 50°C)

Item Sinbol

Head resistance RH 169 176 183 Ω

Head drive voltage Vp 4.2 - 8.5 V

Head drive current

Logic block voltage Vdd 4.5 5.0 5.5 V

Logic block current Idd

"High" input voltage Vih CLK,DAT,LATCH,DST 0.8×Vdd

"Low "input voltage Vil CLK,DAT,LATCH,DST 0 - 0.2×Vdd V

"High"input

current

"Low "input

current

Driver leak current Ileak Vp=7(V), for 1 bit - - 1.0 µA

CLK frequency fclk - - 4 MHz

CLK pulse width t1 See the Timing Chart 80 - - ns

DAT setup-time t2 See the Timing Chart 50 - - ns

DAT hold time t3 See the Timing Chart 50 - - ns

LATCH setup time

LATCH pulse width t5 See the Timing Chart 120 - - ns

LATCH hold time t6 See the Timing Chart 120 - - ns

DST setup time t7 See the Timing Chart 120 - - ns

CLK

DAT

LATCH

DST

CLK

DAT

LATCH

DST

Ip Vp=8.5 V, max. simultaneously

activated dot “64”

Ta=

25°C

Ta=25°C

Iih

Vdd=5.0(V)

Vih=5.0(V)

Ta=25°C

Iil

Vdd=5.0(V)

Vil=0(V)

t4 See the Timing Chart 120 - - ns

Conditions

Waiting for activation - - 0.5 mA

fclk=4MHz,DAT=fixed - - 6 mA

fclk=4MHz,DAT=1/2fclk

MIN TYP

2.5 2.6 2.7 A

- - 10 mA

- - 3 µA

- - 0.5 µA

- - 3 µA

- - 55 µA

- - -3 µA

- - -0.5 µA

- - -3 µA

- - -0.5 µA

Rated

MAX

- Vdd V

Unit

3-18

3.5.7 Timing Chart

Figure 3-10 Timing Chart

3-19

3.6 CONTROLLING THE HEAD ACTIVATION (DST) PULSE WIDTH

3.6.1 Calculation of Head Activation Pulse Width

Head activation pulse width is calculated using the following equation (3).
To execute high quality printing using the LTP1245, the value that is calculated using the following
equation (3) must be adjusted according to the printer’s installation environment. Calculate each value
used according to the steps in Sections 3.6.2 to 3.6.6 and apply the pulse width with the t value that is
obtained by substituting each value into the equation (3).
Printing using too high voltage or too long pulse width may shorten the life of the thermal head.

Equation (3):

E × R
t = × C
V2

t : Head pulse width (ms)
E : Standard applied energy (mJ) See Section 3.6.2.
V : Applied voltage (V) See Section 3.6.3.
R : Head resistance (Ω) See Section 3.6.4.
C : Head pulse term coefficient See Section 3.6.6.

3.6.2 Calculation of Applied Energy

Applied energy should be in accordance with the temperature of the thermal head and the printer’s
installation environment
The thermal head has a built-in thermistor. Measure the temperature using thermistor resistance.
Standard applied energy is based on using the recommended thermal paper (59 µm) and a temperature of
25°C. Calculate the printing energy using equation (4) and the paper coefficient and temperature
coefficient.

Equation (4):
E= (0.285 - T

× (TX - 25) ) × P

C

T

: Detected temperature using the thermistor (°C) 1

X

P : Thermal paper coefficient

Normal thermal paper 1.0
TL69KS-HG76 (label paper) 1.35
TL69KS-R2 (90µm paper) 1.5

T

TL51KS-R2 (62µm paper) 1.5
TW80KK-S (2-ply paper) 2.4

: Temperature coefficient

C

2

TL69KS-R2 0.00285
TL51KS-R2 0.00285
TW80KK-S 0.0037
Other thermal papers 0.003135

1

The thermistor resistance value at TX (°C). See

2

For driving for 2-ply thermal paper, see

Section 3.6.8

Section 3.6.9

.

.

3-20

3.6.3 Adjustment of Head Activation Voltage

Adjustment of head activation pulse width due to changing the head activation voltage is to be in
accordance with equation (5). The adjustment method differs if the head drive voltage (Vp) is 5.5 V or
more or under 5.5 V.

If head temperature is above -5°C

Equation (5):

(5.5 V or more)
V=Vp × 1.2 - 1.8
(under 5.5 V)
V=Vp × 1.4 - 2.9

Vp: Head activation voltage (V)

If head temperature is below -5°C
More than 5.5V : V = Vp ×1.2 - 1.8 + T × 0.01
Less than 5.5V : V = Vp ×1.4 - 2.9 + T × 0.01
T: Thermistor detection temperature (°C)

3.6.4 Adjustment of Head Resistance

Adjustment of head resistance is to be in accordance with equation (6). Due to wiring resistance there is a
drop in voltage.

Equation (6):

( RH + 25 + (RC + rC ) × N ) 2
R= 
RH

RH: Head resistance 178.5 (Ω)
25: Wiring resistance in the thermal head (Ω)
R
r

: Common terminal wiring resistance in the thermal head: 0.1 (Ω)

C

: Wiring resistance between VP and GND (Ω) 1

C

N: Number of dots driven at the same time

1

This resistance is the resistance of the wire used between the FFC terminal of thermal head, the power supply,

the resistance of switching circuit of relay, etc.

3-21

3.6.5 Determination of Activation Pause Time and Activation Pulse Period

Dot lines may be activated in succession to the same thermal dot in order to protect thermal head
elements. Determine the activation period (the time from the preceding activation start to the current
activation start) which conforms to equation (7) to reserve the pause time.

Equation (7):

W > t + 0.5(ms)
W : Activation period of 1-dot line (ms)

3.6.6 Head Activation Pulse Term Coefficient

Make adjustments using the head activation pulse term coefficient (motor drive frequency or equivalent)
as the printing density changes by the printing speed.
According to equations (8), calculate compensation coefficient C of the heat pulse.

Equation (8):

C = 1 -1.15/(1.9+W)
W = 2000 / motor drive frequency

3-22

3.6.7 Calculation Sample for the Head Activation Pulse Width

Table 3-9 displays the calculation sample of the head activation pulse width that was calculated using

equation (3) and the values obtained using equations (4) to (8).

Table 3-9 Activation Pulse Width

Head Drive

Voltage (V)

0 9.92
10 9.07
20 8.21
30 7.35

4.2 40 6.50
50 5.64
60 4.79 4.56
70 3.93 3.75
80 3.07 2.93 2.81

0 5.24 5.00
10 4.79 4.57
20 4.34 4.14
30 3.89 3.70

5.0 40 3.43 3.27 3.14
50 2.98 2.84 2.72
60 2.53 2.41 2.31 2.22
70 2.08 1.98 1.90 1.83 1.76
80 1.62 1.55 1.48 1.43 1.38 1.34

0 3.02 2.88 2.76
10 2.76 2.63 2.52 2.43
20 2.50 2.38 2.28 2.20
30 2.24 2.14 2.05 1.97 1.90

6.0 40 1.98 1.89 1.81 1.74 1.68 1.63
50 1.72 1.64 1.57 1.51 1.46 1.42 1.38
60 1.46 1.39 1.33 1.28 1.24 1.20 1.17
70 1.20 1.14 1.09 1.05 1.02 0.99 0.96
80 0.94 0.89 0.86 0.82 0.80 0.77 0.75

0 1.88 1.80 1.72 1.66 1.60 1.55
10 1.72 1.64 1.57 1.51 1.46 1.42 1.38
20 1.56 1.49 1.42 1.37 1.32 1.28 1.25 1.21
30 1.40 1.33 1.28 1.23 1.19 1.15 1.12 1.09 1.06

7.2 40 1.23 1.18 1.13 1.08 1.05 1.02 0.99 0.96 0.94
50 1.07 1.02 0.98 0.94 0.91 0.88 0.86 0.83 0.81
60 0.91 0.87 0.83 0.80 0.77 0.75 0.73 0.71 0.69
70 0.75 0.71 0.68 0.66 0.63 0.61 0.60 0.58 0.57
80 0.58 0.56 0.53 0.51 0.50 0.48 0.47 0.45 0.44

0 1.45 1.38 1.32 1.27 1.23 1.19 1.16 1.13 1.10
10 1.32 1.26 1.21 1.16 1.12 1.09 1.06 1.03 1.01 0.98
20 1.20 1.14 1.10 1.05 1.02 0.99 0.96 0.93 0.91 0.89
30 1.07 1.02 0.98 0.94 0.91 0.88 0.86 0.84 0.82 0.80

8.0 40 0.95 0.90 0.87 0.83 0.81 0.78 0.76 0.74 0.72 0.71
50 0.82 0.79 0.75 0.72 0.70 0.68 0.66 0.64 0.63 0.61
60 0.70 0.67 0.64 0.61 0.59 0.58 0.56 0.54 0.53 0.52
70 0.57 0.55 0.52 0.50 0.49 0.47 0.46 0.45 0.44 0.43
80 0.45 0.43 0.41 0.39 0.38 0.37 0.36 0.35 0.34 0.33

0 1.25 1.19 1.14 1.10 1.06 1.03 1.00 0.97 0.95 0.93
10 1.14 1.09 1.04 1.00 0.97 0.94 0.91 0.89 0.87 0.85
20 1.03 0.99 0.94 0.91 0.88 0.85 0.83 0.81 0.79 0.77
30 0.93 0.88 0.85 0.81 0.79 0.76 0.74 0.72 0.70 0.69

8.5 40 0.82 0.78 0.75 0.72 0.69 0.67 0.65 0.64 0.62 0.61
50 0.71 0.68 0.65 0.62 0.60 0.58 0.57 0.55 0.54 0.53
60 0.60 0.57 0.55 0.53 0.51 0.50 0.48 0.47 0.46 0.45
70 0.49 0.47 0.45 0.44 0.42 0.41 0.40 0.39 0.38 0.37

Note) The above table shows values for the 59 µm recommended thermal paper (TF50KS-E2D), Rc+rc=0.16 Ω, and N=64.
In the shaded area, the drive pulse width exceeds the allowable activation pulse width or the activation pulse width

80 0.39 0.37 0.35 0.34 0.33 0.32 0.31 0.30 0.29 0.29

exceeds the motor drive frequency. Therefore, use the motor drive frequency shown in the unshaded area.

Thermistor

Temperature

℃

Motor Drive Frequency (PPS)

100 200 300 400 500 600 700 800 900 1000

Do not use this area because paper

feed errors may occur because of the

motor torque.

3-23

3.6.8 Thermistor Resistance

Ω

Ω

°°°°

=

The resistance of the thermistor at the operating temperature T

(°C) is determined using the following

X

equation (10).

Equation (10):

X

25



BEXPR-R




1



××




−

X

+

T273

1

298












R
R

: Resistance at operating temperature Tx (°C)

X

: 15 kΩ ± 10% (25°C)

25

B: 3440 K ± 3%
T

: Operating temperature (°C)

X

EXP (A): The Ath power of natural logarithm e (2.71828)

[Rating]

Operating temperature range: -40°C to +125°C

)

RESISTANCE (k

TEMPERATURE (

C)

Figure 3-11 Thermistor Resistance vs. Temperature

R
E
S

I
S
T
A
N
C
E

(KΩΩΩΩ)

3-24

Table 3- 10 Temperature and Corresponding Thermistor Resistance

Temperature

(°°°°C)

-40 375.54 40 8.63

-35 275.39 45 7.26

-30 204.55 50 6.14

-25 153.76 55 5.22

-20 116.89 60 4.46

-15 89.82 65 3.83

-10 69.71 70 3.30

-5 54.61 75 2.86
0 43.17 80 2.48
5 34.42 85 2.17

10 27.66 90 1.90
15 22.40 95 1.67
20 18.27 100 1.47
25 15.00
30 12.40
35 10.31

3.6.9 How to Print Using 2-ply Thermal Paper

For fine printing, drive the thermal elements two times at half of the drive pulse that was calculated using
equation (3) in Section 3.6.1.

t

2

Thermistor
Resistance (kΩΩΩΩ)

PRINTING TIME

300µµµµs (INTERVAL TIME)

t
2

Temperature

(°°°°C)

t : HEAD DRIVE PULSE WIDTH (ms)

Figure 3-12 How to Drive 2-ply Thermal Paper

Thermistor
Resistance (kΩΩΩΩ)

3-25

3.6.10 Detecting Abnormal Temperatures of the Thermal Head

To protect the thermal head and to ensure personal safety, abnormal thermal head temperatures must be
detected by both hardware and software as follows:

 Detecting abnormal temperatures by software

Design software that will deactivate the heat elements if the thermal head thermistor (TH) detects
a temperature higher than 80 °C (thermistor resistance RTH ≤ 2.48 kΩ), and reactivate the heat
elements when a temperature lower than 60 °C (RTH ≥ 4.46 kΩ) is detected. If the thermal head
continues to be activated at a temperature higher than 80 °C, the life of the thermal head may be
shortened significantly.

 Detecting abnormal temperatures by hardware

If the control unit (CPU) malfunctions, the software for detecting abnormal temperatures may not
function properly, resulting in overheating of the thermal head. Overheating of the thermal head
may cause damage to the thermal head or cause skin burns.
Always use hardware in conjunction with software for detecting abnormal temperatures to ensure
personal safety. (If the control unit malfunctions, it may be impossible to prevent damage to the
thermal head even if a detection of abnormal temperature is detected by hardware.).

Using a window comparator circuit or similar detector, design hardware that detects the following
abnormal conditions:

(a) Overheating of the thermal head (approximately 100 °C or higher (RTH ≤ 1.47 kΩ)).

(b) Faulty thermistor connection (the thermistor may be open or short-circuited).

If (a) and (b) are detected, immediately deactivate the heat elements. Reactivate the heat
elements after they have returned to normal.

3-26

3.7 HEAD-UP/PAPER DETECTOR

LTP1245 has a built-in head-up detector to detect whether the head is up or down and a paper detector to
detect whether paper is present or exhausted.
Both detectors are reflection photo interruptors which are designed to output signals as shown in Table
3-11 according to their status.

The external circuit should be designed so that it detects output from the head-up and paper detector and
does not activate the thermal head when the head is in the up position and paper is exhausted. If the
thermal head is activated in the head up position, the thermal head may be damaged or the life of the head
may be shortened significantly. If the thermal head is activated in an out-of paper mode, the thermal head
and platen roller may be damaged.

Table 3-11 Detector’s Status and Output Signals

Detector Status Output signal

Head up detector

Paper detector

* Sensing by the head up detector is delayed from the actual completion of the

head up/down action.

3.7.1 General Specifications

Table 3-12 Absolute Maximum Ratings of Detectors

Item Symbol Rating

LED (input)

Phototransistor
(output)

Operating temperature T
Storage temperature T

Forward current I
Peak forward current I
Reverse voltage V
Collector-to-emitter
voltage
Emitter-to-collector
voltage
Collector current I
Collector loss P

Head down “Low”

Head up “High”

Paper exist “Low”

No paper “High”

F

FM

R

V

CEO

V

ECO

C

C

opr

stg

-25°C to + 85°C

-40°C to + 100°C

(at 25°C)

30 mA

0.4 A
5 V

30 V

5 V

20 mA

50 mW

3-27

Table 3-13 Detectors Input / Output Conditions

Item Symbol

Forward voltage

(input)
Photo-transistor

Reverse current

Dark current I
(output)
Transfer
characteristics

Photo electric

current

Response time

(at rise)

Response time

(at fall)

1

d = sensing distance

Leak current I

3.7.2 Sample External Circuit

Conditions Std. Max.

V

I

CEO

I

IF=10mA 1.15V 1.3V LED

F

VR=5V - 10µA

R

VCE=24V - 0.1µA

IF=10mA, VCE=5V 450µA 1100µA

C

tr IC=1mA, VCE=10V 10µs -

tf RL=1kΩ, d=1mm 1 10µs -

LEAK IF

=10mA, VCE=5V - 0.2µA

The HS signal is high when the thermal head is in the “up” position.
The PS signal is high when paper is exhausted.

Figure 3-13 Sample External Circuit of the Head-Up/Paper Detector

3-28

3.7.3 Automatic Paper Load

*

specified number of steps.

Stand

-

by for print operation

*

Deviation in the force of the rubber roller

Paper can be automatically loaded when used in conjunction with the paper detector. To prevent paper
from skewing, cut the edges at right angles in line with the paper feed direction before loading it.

If skewed, feed the paper until it is straight, or place the head in the up position and adjust the paper so that
it is fed straight.

Figure 3-13 shows a flowchart for automatically loading paper.

START

Paper exists.

Paper is
exhausted.

Paper is present.

CHECK FOR

PAPER

CHECK FOR

PAPER

Head up/down

detection

Head down

Drive the motor in the
normal direction by the

END

Paper is
exhausted.

Head up

Drive the motor at lower than the frequency
during automatic paper loading described in

3.3 PAPER FEED CHARACTERISTICS.

Set the number of motor drive steps in
consideration of:

•

to catch the paper

• Distance to the paper eject

The distance between the paper detector and
the heat elements is approximately 8 mm.

Figure 3-14 Flowchart for Automatic Paper Load

3-29

3.8 Mode Code Label

１２３４５６７８９

ＸＹＺ

Figure 3-14 shows that the printer is the LTP1245R-C384-E which is made in September 2004.
See Figure 7-1 LTP1245R-C384-E Appearance and Dimensions for labeling position.

(1) Manufactured year: 2004
(2) Model code: LTP1245R-C384-E
(3) Manufactured month: September (X: October, Y: November, Z: December)

３ ４ ５ ６ ７ ８ ９ ０

２

１

ＬＴＰ１２４５Ｒ－Ｃ３８４－Ｅ

Figure 3-15 Model Code Label

3-30

CHAPTER

CONNECTING EXTERNAL CIRCUITS

The LTP1245 has two types of connectors to connect it to the external circuits: FPC (Flexible Printed
Cable) type connector and FFC (Flexible Flat Cable) type connector.

Table 4-1 shows the recommended connectors.

Table 4-1 Recommended Connectors

No. External Circuit

Functions

Thermal head control

1

Motor control, paper

2

detection, and head-up
detection

Number of

Pins

20

9

4

Recommended Connectors

(External Circuit side)

Molex Co., Ltd.
52044-2045 (horizontal type)
52045-2045 (vertical type)
5597-20APB7F (horizontal type)
5597-20CPB7F (vertical type)
Molex Co., Ltd.
52030-0919 (vertical type)
52089-0929 (horizontal type)

4-1

4.1 THERMAL HEAD CONTROL TERMINALS

Figure 4-1 shows the FFC terminals of the thermal head control.

20

1

Figure 4-1 Thermal Head Control Terminals (FFC)

Table 4-2 Thermal Head Control Terminal Assignments

Terminal

Number

1 Vp
2 Vp

Signal Name Input/

Output

Input Thermal head drive voltage
Input Thermal head drive voltage

Function

3 GND - GND
4 GND - GND
5 GND - GND
6 DAT Input Print data input (serial input)
7 CLK Input Synchronizing signal for data transfer
8 LATCH Input Print data latch (memory storage)

9 DST6 Input Thermal head print activation instruction signal
10 DST5 Input Thermal head print activation instruction signal
11 DST4 Input Thermal head print activation instruction signal
12 DST3 Input Thermal head print activation instruction signal
13 DST2 Input Thermal head print activation instruction signal
14 DST1 Input Thermal head print activation instruction signal
15 TH - Thermistor
16 Vdd Input Logic power supply (5V)
17 GND - GND
18 GND - GND
19 Vp
20 Vp

Input Thermal head drive voltage
Input Thermal head drive voltage

4-2

4.2 MOTOR AND DETECTOR TERMINALS

Figure 4-2 shows the FPC terminals of the motor control, paper detector and head-up detector.

9

1

Figure 4-2 Motor and Detector Terminals (FPC)

Table 4-3 Motor and Detector Terminals Assignments

Terminal

Signal Name

Function

Number

1 HS

Output signal of the head-up detector
(collector output of a photo-transistor)

2 V

HS

Power supply of the head-up detector
(LED anode)

3 GND GND

(common ground for the head-up and paper detectors)

4 PS Output signal of the paper detector

(collector output of a photo-transistor)

5 VPS Power supply of the paper detector

(LED anode)

6

7

8

9 B Motor drive signal

A Motor drive signal

B Motor drive signal

A Motor drive signal

4-3

4-4

CHAPTER

5

DRIVE METHOD

5.1 THERMAL HEAD DRIVE TIMING

 Input of print data

Input of DAT and CLK transfer the print data to the shift register in serial input. “High” means
printing and “Low” means no-printing in DAT. DAT data is read in at the rising edge of the CLK
inputs. The transferred line of data is stored in the latch register by turning LATCH to “Low”.

 Input of the head activation pulse

"High" of DST drives the heat elements of the thermal head. Then let DST go to "Low" after driving
for the period calculated using the formula shown in "3.6 CONTROLLING THE HEAD

ACTIVATION (DST) PULSE WIDTH".

Figure 5-1 shows the example of timing chart of the thermal head driving.

CLK

DAT

Data transfer

Data transfer

1

LATCH

Latching data

DST

1:

The print data for next dot line can be transfered immediately after storing the print data into the latch register.

Figure 5-1 Example of Timing Chart of the Thermal Head Driving

5-1

5.2 MOTOR DRIVE TIMING

The phase of motors and the thermal head need to be synchronized to print.
As example, the print method which divides one dot line to two groups; the blocks 1,3, and 5 and the
blocks 2,4, and 6, and prints each group data for each step of the motor is described below.
Basic pulse width of the motor drive pulse, Tm, is a value (unit: msec) of the reciprocal number of the
driving frequency calculated using equation (1) of "3.3 PAPER FEED CHARACTERISTICS".

 Pause State

Transfer the print data to the thermal head according to "5.1 THERMAL HEAD DRIVE TIMING".

 Start up phase

Excite the phase which is output just before the motor stops for the time of the start up in
Table 3-5.

 1st line, 1st step

Drive the motor by one step (1st step). The step time should be the acceleration 1st step time or
Tm, whichever is longer.
Set DST for the blocks 1, 3, and 5 to “High” in synchronization with the motor drive.
After setting DST to “High”, set DST to “Low” when the driving time calculated in
“3.6 CONTROLLING THE HEAD ACTIVATION (DST) PULSE WIDTH” has passed.
Move to the 2nd step after the transfer of print data for the blocks 1, 3 and 5 and the 1st step time
of the motor.

 1st line, 2nd step

Drive the motor by one step (2nd step). As to how much step time is output, compare Tm with the
time that was taken in the previous step.

(1) In case Tm < the time that was taken in the previous step,

the next closest acceleration step time to the previous step time or Tm, which is longer, is
output.

(2) in case Tm > the time that was taken in the previous step,

the closest acceleration step time to Tm and the acceleration step time that is larger than Tm,

are output.

Set DST for blocks 2, 4, and 6 to “High” in synchronization with the motor drive. After setting DST
to “High”, set DST to “Low” after completion of the head activation time. Transfer the print data of
the next dot line to the thermal head after completion of printing for blocks 2, 4, and 6.
Move to the 2nd dot line after completion of the 2nd step time of the motor and the transfer of print
data for the next dot line.

5-2

 2nd line, 1st step

Drive the motor by one step (3rd step). As to how much step time is output, compare Tm with the
time that was taken in the previous step.

(1) in case Tm < the time that was taken in the previous step,

the next closest acceleration step time to the previous step time or Tm, which is longer, is
output.

(2) in case Tm > the time that was taken in the previous step,

the closest acceleration step time to Tm and the acceleration step time that is larger than Tm,
are output.

Activate blocks 1, 3, and 5 in the same manner as the 1st line.

 2nd line, 2nd step

Drive the motor by one step (4th step). As to how much step time is output, compare Tm with the
time that was taken in the previous step.

(1) in case Tm < the time that was taken in the previous step,

the next closest acceleration step time to the previous step time or Tm, which is longer, is

output.

(2) in case Tm > the time that was taken in the previous step,

the closest acceleration step time to Tm and the acceleration step time that is larger than Tm,
are output.

Activate blocks 2, 4, and 6 in the same manner as the 1st dot line, then transfer the next dot line
data.

Print each line in the same manner continuously.

Figure 5-2 shows an example of the motor drive timing chart.

5-3

B

A

A

B

CLK

DAT

LATCH

START STOP

1ST STEP OF
THE 1ST DOT LINE

2ND STEP OF
THE 1ST DOT LINE

ST

STEP OF

1
THE 2ND DOT LINE

2ND STEP OF
THE 2ND DOT LINE

DST

1,3,5
Block

2,4,6

Block

1,3,5

Block

Figure 5-2 Example of Motor Drive Timing Chart

2,4,6

Block

5-4

CHAPTER

HOUSING DESIGN GUIDE

6.1 SECURING THE PRINTER

The LTP1245 can be secured to the outer casing with screws.

6.1.1 Printer Mounting Method

Secure the printer with a mounting hole (φ 2.8) and 2 shaped indents.
See "CHAPTER 7 APPEARANCE AND EXTERNAL DIMENSION" for locations and dimensions.

Recommended Screws and Washers

Recommended mounting screws and washers are as follows:

①

A combination of:

M2.5 or M2.6 pan head Phillips screw and

2.5 or 2.6 small round flat washer

A combination of:

②

Pan head tapping screw 2.5 for resin and

2.5 small round flat washer

*

Screws and washers with 6 mm or less outer diameter and 5 mm or less height in accordance with ①

and ②.

6.1.2 Precautions for Securing the Printer

Secure the printer with the following attentions.
Securing the printer incorrectly may cause a deterioration of print quality, a paper skew, a paper jam
and/or excessive noise.

 Design a printer mounting surface to secure the printer on the flat surface.
 Prevent excessive force, deformation or torsion on the printer when securing it.
 Secure the printer with 2 to 3 kgf screw torque in the up position of the thermal head.
 Design the case so that the thermal head terminal can be moved in 2 to 3 mm range due to the

head up/down action.

6

6-1

6.2 LAYOUT OF PRINTER AND PAPER

 Design the paper outlet angle in 0 to 45°. (See Figure 6-1)

HEAT ELEMENT

Paper outlet angle (θ) : 0°≤θ≤45°

THERMAL PAPER ROLL

The distance between the paper
detector and the heat element is
approximately 8 mm.

THERMAL HEAD

MOUNTING FACE

θ

PLATEN

PAPER DETECTOR

Figure 6-1 Paper Layout

6.3 WHERE TO MOUNT THE PAPER HOLDER

When determining the layout of paper holder, note the following:

 When you use a paper roll, set the holder so that the paper is in alignment with the paper intake

with no horizontal offset, and that the center axis of the paper roll is parallel with the printer.

 Keep the paper feed force 50 gf or less.

6.4 WHERE TO MOUNT THE PAPER CUTTER

Install the paper cutter so that it does not interfere with the paper feed. The angles and positions for
feeding paper are shown in "CHAPTER 7 APPEARANCE AND DIMENSIONS".

 If the distance between the edge of the thermal head and the edge of the fed paper is too small,

the paper may be caught by the platen. Please take this into account when designing.

 Use a cutter with a sharp edge so that paper is cut with the paper hold force or less.

6-2

6.5 OUTER CASING STRUCTURE

Figure 6-2 shows a sample structure for the outer casing.

* Provide a gap of a few mm between the printer and the outer casing since the area over the thermal head becomes very

hot.

Figure 6-2 Sample Outer Casing Structure

6-3

6-4

CHAPTER

APPEARANCE AND DIMENSIONS

Figure 7-1 shows the appearance and external dimensions of the LTP1245.

7

7-1

Figure 7-1 LTP1245R-C384-E Appearance and Dimensions

Unit : mm

Tolerance: ±0.5 mm

7-2

Figure 7-2 LTP1245S-C384-E Appearance and Dimensions

Unit : mm

Tolerance: ±0.5 mm

7-3

Unit : mm

Tolerance: ±0.5 mm

Figure 7-3 LTP1245T-S384-E Appearance and Dimensions

7-4

Unit : mm

Tolerance: ±0.5 mm

Figure 7-4 LTP1245U-S384-E Appearance and Dimensions

7-5

7-6

CHAPTER

LOADING/UNLOADING PAPER AND HEAD CLEANING

8.1 LOADING/UNLOADING PAPER PRECAUTIONS

①①①① Loading paper

 Load paper with the thermal head in the up position.

(See Figure 8-1 Head Cleaning Procedure (b) in Section 8.2 “HEAD CLEANING
PROCEDURES AND PRECAUTIONS”).

 Cut the edge of the paper so that the center of the paper will be inserted first

8

GOOD

NO GOOD NO GOOD NO GOOD

 Insert the paper straight into the paper inlet.

 When the edge of the paper comes up from between the thermal head and the platen, pull the

edge of the paper, check whether the paper is aligned correctly, and place the thermal head into
the down position.

②②②② Unloading paper

 Unload paper with the thermal head in the up position.

(See Figure 8-1 Head Cleaning Procedure (b) in Section 8.2 “HEAD CLEANING
PROCEDURES AND PRECAUTIONS”).

 Pull the paper straight up by hand in the direction in which the paper is normally fed.

 If the paper is bonded on the core of the paper roll, separate the paper from the core and then pull

the paper out.

8-1

③③③③ Auto-loading paper

 Cut the edge of the paper so it is vertical to the direction of the paper feed.

NO GOOD

GOOD NO GOOD

NO GOOD

 Load paper with thermal head in the down position.

 If the paper skews, place the thermal head in the up position and reset the paper.

 If the thermal head has been in the down position for a long time, it will be impossible to insert

because the head is in contact with the platen. In this case, place the head in the up position once
and insert the paper again.

8-2

8.2 HEAD CLEANING PROCEDURE AND PRECAUTIONS

PROCEDURE :

①

Lift the head up lever (a) so it stands upright (b).

②

Clean the heat elements using alcohol and a cotton swab.

③

After cleaning, set the head up lever to its original position by reversing the steps.

PRECAUTIONS :

①

Do not clean the thermal head immediately after printing bacause thermal head will still be hot.

②

Cleaning fluid: ethyl alcohol, isopropyl alcohol.

③ Do not use sandpaper, cutter, etc. when cleaning. They will damage the heat elements.

④

Do not start printing operation until alcohol dries.

(a)

(b)

HEAD UP LEVER PLATEN ROLLER

Figure 8-1 Head Cleaning Procedure

8-3

HEAT ELEMENT

8-4

CHAPTER

9

PERIPHERAL EQUIPMENT

9.1 AUTOCUTTER UNIT

The LTP1245 can be equipped with the ACU6205 autocutter unit.
The ACU6205 autocutter unit uses the circular cut method.
The circular cut method enables the ACU6205 autocutter unit to be compact and lightweight.

For the specifications and the mechanism of how the ACU6205 operates, see the ACU6205

AUTOCUTTER UNIT TECHNICAL REFERENCE.

9-1

①

9.1.1 Installation

(1) When Using a Special Mount

1) Secure the printer on the special mount (OP-L1200-E) with the special screws.

①

2) The recommended tightening torque is 3 kgf cm (

3) Use four screws to secure the mount on the cabinet. Recommended screws: M2.6 (②

in Figture 9-1).

4) Connect the FPC and FFC of the printer to the main unit.

5) Install the ACU6205 autocutter unit from the grounding plate side (③,④ in Figure 9-1).

6) Connect the cutter leads.

in Figure 9-1).

④

③

②

②

②

②

Figure 9-1 Installation

9-2

(2) When Designing a Mount

Design a mount so that the fulcrum for rotation is located as shown in Figure 9-2.

Fulcrum for rotation

Figure 9-2 Designing a Mount

9.1.2 Opening and Closing the Autocutter Unit

Open the autocutter unit to insert sheets of paper manually or to clear paper jams. To open the
autocutter unit, lift the part shown in Figure 9-3. Care should be taken to avoid causing damage to the
platen. Before closing the autocutter unit, verify that the print head is down. Close the autocutter unit
until it clicks.

Note 1: Do not raise the head when the autocutter unit is closed. Set the head up lever to the position
shown in Figure 9-4 to clear paper jams.

Figure 9-3 Opening and Closing of Autocutter Unit Figure 9-4 Head up Lever Position

9-3

9.1.3 Inserting Recording Paper

(1) Automatic paper insertion

Paper can be inserted automatically with the autocutter unit closed.
See ③ in Section 8.1, LTP1245 LINE THEMAL PRINTER MECHANISM TECHNICAL

REFERENCE.

(2) Manual paper insertion

Open the autocutter unit and insert paper.
See ① in Section 8.1, LTP1245 LINE THERMAL PRINTER MECHANISM TECHNICAL

REFERENCE.
After the printer setup, insert the paper into the paper feed slit in the autocutter, then close the
autocutter unit.

(3) Recording paper removal

With the autocutter unit closed, turn the head up lever to the position shown in Figure 9-4,

release the head and pull the paper out straight.

For information on how to clear paper jams, see Section 9.1.4.

9.1.4 Clearing Paper Jams

If a paper jam occurs, clear it as follows:

1) Turn off the printer and the autocutter.

2) Open the autocutter unit and remove the jammed paper.

For information on paper jams in the autocutter, see CHAPTER 5, "CANCELING MOTOR

(MOVABLE EDGE) LOCK IN THE "ACU6205 AUTOCUTTER UNIT TECHNICAL
REFERENCE".

9-4

9.1.5 Hints for Use

PRINT AREA B

(1) Do not back feed paper after cutting paper using the autocutter unit because it will cause a paper

jam.

(2) To prevent paper from jamming, feed paper or print feed more than 3 mm after cutting paper.

(3) To make the most efficient use of paper, as shown in Figure 9-5, print area A for the next print

portion after printing area B, and then cut the paper.

(4) If a partial cut is performed, the backlash absorption steps (40-step reverse rotation and 40-step

normal rotation) should be included when printing starts after cutting paper (after pulling paper).

INITIAL
PRINTING AREA

PRINT AREA A

PRINT AREA A

PRINT AREA B

PAPER FEED DIRECTION

CUT POSITION

PRINT START POSITION

* Do not print on the cut position.

Figure 9-5 Best Cutting Position for Efficient Paper Use

9-5

9.1.6 External View when the LTP1245 is equipped with the Autocutter

unit: mm

Figure 9-6 External View when the LTP1245 is equipped with the Autocutter

9-6

9.2 LTP1245 MOUNT (OP-L1245A-E)

The LTP1245 can be secured on the cabinet using the LTP1245 mount (OP-L1245A-E) and four

screws.

9.2.1 Installation

Align the two notches of the printer with the tabs on the LTP1245 mount (OP-L1245A-E) and secure the

printer by installing a special screw (No.0 cross-recessed machine screw; tightening torque:

3 kgf • cm) in the printer installation hole. (2.8 mm diameter) (Figure 9-7).

LTP1245R

Tabs

Special

screw

OP-L1245A-E

Figure 9-7 LTP1245 Mount Installation

9-7

9.2.2 OP-L1245A-E External View

Unit:mm

Figure 9-8 LTP1245 Mount External View (OP-L1245A-E)

9-8