Seiko LTPH245 Use and care manual

Seiko Instruments Inc.
LTPH245
LINE THERMAL PRINTER MECHANISM
TECHNICAL REFERENCE
U00055332011

Copyright © 1999-2012 by Seiko Instruments Inc.
All rights reserved.
Seiko Instruments Inc. (hereinafter referred to as “SII”) has prepared this technical reference 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.
is a trademark of Seiko Instruments Inc.
LTPH245 LINE THERMAL PRINTER MECHANISM TECHNICAL REFERENCE
Document Number U00055332011
First Edition December 1999
Second Edition May 2000
Third Edition December 2000
Fourth Edition March 2001
Fifth Edition August 2001
Sixth Edition December 2001
Seventh Edition March 2003
Eighth Edition March 2005
Ninth Edition July 2006
Tenth Edition April 2007
Eleventh Edition October 2009
Twelfth Edition May 2012

iii
PREFACE
This technical reference describes the specifications and basic operating procedures for the LTPH
series thermal printer mechanism (hereinafter referred to as “printer”).
The LTPH245 series (RoHS compliance) has the following models.
LTPH245D-C384-E
LTPH245E-C384-E
This technical reference usually describes information common to any printer unless otherwise
specified. If the information is different depending on the model, specific model name is mentioned
clearly.
Chapter 1 “Precautions” describes safety, design, and handling precautions. Read it thoroughly
before designing so that you are able to use the product properly.
SII has not investigated the intellectual property rights of the sample circuits included in this
technical reference. Fully investigate the intellectual property rights of these circuits before using.
In particular, SII reserves the industrial property rights for the Heat Storage Simulation described in
Chapter 3. Using it for the other printer is infringement on the industrial property rights.

v
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...................................................................................... 1-4
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 ......................................................................................................... 3-12
3.5.1 Structure of the Thermal Head........................................................................ 3-12
3.5.2 Printed Position of the Data............................................................................. 3-14
3.5.3 Head Resistance............................................................................................. 3-15
3.5.4 Head Voltage................................................................................................... 3-16
3.5.5 Peak Current ................................................................................................... 3-16
3.5.6 Thermal Head Electrical Characteristics......................................................... 3-17
3.5.7 Timing Chart.................................................................................................... 3-18
3.6 CONTROLLING THE HEAD ACTIVATION (DST) PULSE WIDTH............................. 3-19
3.6.1 Calculation of Head Activation Pulse Width.................................................... 3-19
3.6.2 Calculation of Applied Energy......................................................................... 3-19
3.6.3 Calculation of Head Activation Voltage........................................................... 3-20
3.6.4 Calculation of Head Resistance...................................................................... 3-20
3.6.5 Determination of Activation Pause Time and Activation Pulse Period............ 3-21
3.6.6 Head Activation Pulse Term Coefficient.......................................................... 3-21
3.6.7 Head Storage Coefficient................................................................................ 3-22
3.6.8 Calculation Sample for the Head Activation Pulse Width ............................... 3-23
3.6.9 Thermistor Resistance .................................................................................... 3-24
3.6.10 Detecting Abnormal Temperatures of the Thermal Head............................... 3-26
3.7 OUT-OF-PAPER SENSOR.......................................................................................... 3-27

vi
Section Page
3.8 PLATEN POSITION SENSOR..................................................................................... 3-28
3.8.1 General Specification...................................................................................... 3-28
3.8.2 Sample External Circuit .................................................................................. 3-28
3.9 MODEL CODE LABEL................................................................................................. 3-29
CHAPTER 4 CONNECTING EXTERNAL CIRCUITS
4.1 THERMAL HEAD CONTROL TERMINALS................................................................. 4-1
4.2 MOTOR AND SENSOR TERMINALS ......................................................................... 4-3
4.3 CAUTION IN CONNECTION ....................................................................................... 4-4
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 Mounting Platen Block..................................................................................... 6-2
6.1.3 Precautions for Securing the Printer............................................................... 6-4
6.2 LAYOUT OF PRINTER AND PAPER .......................................................................... 6-5
6.3 WHERE TO MOUNT THE PAPER HOLDER.............................................................. 6-5
6.4 SETTING THE PAPER ................................................................................................ 6-5
6.5 POSITIONING THE PAPER CUTTER......................................................................... 6-6
6.6 OUTER CASE STRUCTURE....................................................................................... 6-7
CHAPTER 7 APPEARANCE AND DIMENSIONS
CHAPTER 8 LOADING/UNLOADING PAPER AND CLEANING
8.1 LOADING/UNLOADING PAPER PRECAUTIONS ...................................................... 8-1
8.2 CLEANING PROCEDURE AND PRECAUTIONS....................................................... 8-3
8.2.1 PRECAUTIONS .............................................................................................. 8-3
8.2.2 PROCEDURE ................................................................................................. 8-3

vii
FIGURES
Figure Page
3-1 Heat Element Dimensions............................................................................................ 3-3
3-2 Print Area...................................................................................................................... 3-3
3-3 Sample Drive Circuit..................................................................................................... 3-6
3-4 Input Voltage Signals for the Sample Drive Circuit...................................................... 3-7
3-5 Motor Start/Stop Timing................................................................................................ 3-8
3-6 Motor Drive Timing Chart (in use at temperature over -5℃)........................................ 3-10
3-7 Motor Drive Timing Chart (in use at temperature under -5℃) ..................................... 3-11
3-8 Thermal Head Block Diagram...................................................................................... 3-14
3-9 Printed Position of the Data.......................................................................................... 3-15
3-10 Timing Chart................................................................................................................. 3-18
3-11 Thermistor Resistance vs. Temperature...................................................................... 3-24
3-12 Sample External Circuit of the Out-of-Paper Sensor ................................................... 3-27
3-13 Sample External Circuit of the Platen Position Sensor................................................ 3-28
3-14 Model Code Label ........................................................................................................ 3-29
4-1 Thermal Head Control Terminals................................................................................. 4-1
4-2 Motor and Sensor Terminals........................................................................................ 4-3
5-1 Example of Timing Chart of the Thermal Head Driving ............................................... 5-1
5-2 Example of Motor Drive Timing Chart.......................................................................... 5-3
6-1 How to secure the printer............................................................................................. 6-1
6-2 How to secure the Platen Block ................................................................................... 6-2
6-3 Mounting Position of the Platen Block.......................................................................... 6-3
6-4 Paper Path.................................................................................................................... 6-5
6-5 Paper Cutter Mounting Position ................................................................................... 6-6
6-6 The Blade of the Paper Cutter...................................................................................... 6-6
6-7 Sample Outer Case Structure...................................................................................... 6-7
7-1 Appearance and Dimensions (LTPH245D-C384-E).................................................... 7-2
7-2 Printer Main Body Appearance and Dimensions (LTPH245D-C384-E) ...................... 7-3
7-3 Appearance and Dimensions (LTPH245E-C384-E) .................................................... 7-4
7-4 Printer Main Body Appearance and Dimensions (LTPH245E-C384-E)....................... 7-5
7-5 Platen Block Appearance and Dimensions.................................................................. 7-6
8-1 Loading Paper (1)......................................................................................................... 8-1
8-2 Loading Paper (2)......................................................................................................... 8-2
8-3 Cleaning Procedure...................................................................................................... 8-3

viii
TABLES
Table Page
3-1 General Specifications ................................................................................................. 3-1
3-2 Sample Motor Drive Frequency ................................................................................... 3-4
3-3 General Specifications of the Motor............................................................................. 3-5
3-4 Excitation Sequence..................................................................................................... 3-7
3-5 Acceleration Steps ....................................................................................................... 3-12
3-6 Blocks and Activated Heat Elements........................................................................... 3-15
3-7 Head Resistance Ranks............................................................................................... 3-15
3-8 Head Voltage................................................................................................................ 3-16
3-9 Thermal Head Electrical Characteristics...................................................................... 3-17
3-10 Activation Pulse Width.................................................................................................. 3-23
3-11 Temperature and Thermistor Resistance .................................................................... 3-25
3-12 Out-of-Paper Sensor.................................................................................................... 3-27
4-1 Recommended Connectors ......................................................................................... 4-1
4-2 Thermal Head Control Terminal Assignments............................................................. 4-2
4-3 Motor and Sensor Terminals Assignments.................................................................. 4-3

1-1
1
PRECAUTIONS
Read through this manual to design and operate the printer properly.
Pay special attention to the precautions noted in each section.
1.1 SAFETY PRECAUTIONS
Follow these precautions when designing a product using the printer, and include any necessary
precautions and warning labels to ensure the safe operation of your product by users.
Preventing the thermal head from overheating
When electricity is continuously supplied to the thermal head heat element by a CPU or other
malfunction, the thermal head may overheat, causing smoke and fire.
Follow the method described in Section 3.6.10 to monitor the temperature of the thermal head
to prevent overheating.
Turn the printer off immediately if any abnormal conditions occur.
Preventing the user from touching the thermal head and motor
Warn the user not to touch the thermal head, its periphery or motor as they are hot during and
immediately after printing. Failure to follow this instruction may lead to personal injury
including burns.
Also, allow cooling by designing clearance between the head, motor and the outer case.
Preventing the user from touching the rotary drive portion
Design the product so that the motor does not operate when the outer case and platen block
are open. The user could be caught in the motor when the drive gear is exposed.
CHAPTER

1-2
1.2 DESIGN AND HANDLING PRECAUTIONS
To maintain the initial level of performance of the printer 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 apply a pulse of 2V and 20 nsec or higher to each signal terminal of the thermal head.
Use C-MOS IC chips (74HC240 or equivalent) for interfacing the 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) with the FG connector as shown in Figure 7-2.
Connect the GND terminal (SG) to FG through 1 Mresistor so that the electric potential
of the SG of the thermal head and the FG of the printer are equal.
Keep the Vp power off when not printing 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.
Wire resistance should be 50 mor less (however the less the better) between the power
supply and the Vp, and the GND terminals on the thermal head controller. Maintain a
considerable distance from signal lines to reduce electrical interference.
The surge voltage between Vp and GND should not exceed 10 V.
As a noise countermeasure, connect the capacitor noted below between the Vdd and GND
terminals near the thermal head control connector.
Vp GND: approximately 10F
Vdd GND: approximately 1F
When turning the power on or off, perform the Vp and Vdd simultaneously or in the order of 1)
and 2) as follows:
At power ON: 1) Vdd (5 V) 2) Vp
At power OFF: 1) Vp 2) Vdd (5 V)
Always monitor the output of the platen position sensor and out-of-paper sensor. Incorrect
activation of the thermal head may damage and reduce the longevity of the thermal head and
the platen.
Design the outer case so that the out-of-paper sensor is not affected by light from outside.
Since a reflection type photo interrupter is used in the out-of-paper sensor, the sensor may be
affected by light from outside.

1-3
Allow for movement of the FFC when designing the outer case because the FFC will shift 1 to 2
mm from the thermal head moving. Also, design the outer case so that it prevents the paper
feed out from being caught in the platen.
Surface of thermal paper may get scratched by backward feed. The backward feed may cause
paper skew and jams depending on paper roll layout and designing of paper holder. Be sure to
confirm performance with your product before using the backward feed.
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 and then 40 steps in the normal direction
during initialization, a time after backward feeding and a time after setting/releasing the platen
block.
If printing at a high print ratio for longer length, non-printing area may be colored. Verify the
performance with your actual device.
For the position in which the
platen block should be fixed,
and the way it is mounted,
follow the instructions shown
in Figure 6-3.
Since the printer mechanism
does not have the function to
prevent paper from sliding,
design the outer case so that
the paper is guarded securely.
Design so that the
paper feed load is
0.49N (50 gf) or
less.
As to the center of the rotation of the
cover of the platen block that is
mounted, follow the instructions
shown in Figure 7-1.
The lever should be used when removing and
installing the platen block. It should never be
pulled by force.

1-4
1.2.2 Handling Precautions
To maintain the initial level of performance of the printer and to prevent future problems from occurring,
observe the following precautions.
Also, include any necessary precautions to ensure the safe operation of your product by users.
To protect the heat elements, ICs, etc. from static electricity, discharge all static electricity
before handling the printer.
Pay special attention to the thermal head control terminals when handling.
Do not apply stress to the thermal head control terminals: Doing so may damage the
connectors and FFC (Flexible Flat Cable).
Using anything other than the specified paper may cause the following:
Poor printing quality
Abrasion of the thermal head
The thermal surface of the paper and the thermal head may stick together
Excessive noise
Fading print
Corroded thermal head
Always print or feed with the specified paper inserted to protect the platen, thermal head, and
reduction gear.
Do not hit or scratch the surface of the thermal head with sharp or hard objects as it may
damage the heat element.
If the thermal head remains in contact with the platen, the platen may become deformed and
deteriorate print quality.
If the platen is deformed, the uneven surface of the platen can be recovered by feeding paper
for a while.
Never connect or disconnect cables with the power on. Always power off the printer first.
When printing a black or checkered pattern at a high print rate 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.
If water condenses on the printer, keep the thermal head away from water drops as it may
corrode the thermal head, and turn printer power off until it dries.
Prevent contact with water and do not operate with wet hands as it may damage the printer or
cause a short circuit or fire.
Never use the printer in a dusty place, as it may damage the thermal head and paper feeder.
Do not use the printer in corrosive gas and siloxane atmosphere as it may cause contact
failure.
1.2.3 Precautions on Discarding
When discarding used printers, discard them according to the disposal regulations and rules of each
respective district.

2-1
2
FEATURES
The LTPH245 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 printer can bebattery driven, it can easily be mounted onto a portable
device such as a hand-held terminal.
The LTPH245 has the following features:
Battery drive
Since the range of operating voltage of 4.2V to 8.5V is wide, four to six Ni-Cd batteries or
Ni-MH batteries or two Lithium-ion batteries can also be used.
Compact and light weight 1
The mechanism is compact and light: 76.8 mm in width, 38 mm in depth, 16 mm in height, and
approximately 46 g in weight.
Improved operability
The platen roller can be released easily by lever operation allowing easy paper installation and
head cleaning.
High resolution printing
A high-density print head of 8 dots/mm produces clear and precise printing.
Longevity
The mechanism is maintenance-free with a long life of 50 km print length and/or 100 million
pulses.
High speed printing 2
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 are attainable.
Low current consumption
The printer can be driven on low discharge current lithium-ion batteries due to low current
consumption. Continuous printing can be also performed.
CHAPTER

2-2
Low noise
Thermal line dot printing is used to guarantee low-noise printing.
Realizing easy design of outer case
The printer mechanism is designed to fit easily into the outer case, allowing for
reduced number of outer case parts.
1The external dimensions exclude those of the lever and platen frame. 46 g in weight
includes all parts.
2Print speed differs depending on working and environmental conditions.

3-1
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) 1
450 dot lines/s (56.25 mm/s) (at 7.2 V) 1
500 dot lines/s (62.5 mm/s) (at 8.0 V) 1
Paper feed pitch 0.125 mm
Head temperature detection Via thermistor
Platen position detection Via mechanical switch
Out-of-paper detection Via photo interrupter
Operating voltage range
V
Pline (for head and motor drive)
V
dd line (for head logic)
4.2 V to 8.5 V 7
(equivalent to four through six Ni-Cd or Ni-MH
batteries, or two lithium-ion batteries)
4.5 V to 5.5 V
Current consumption
For driving the head (VP)
For driving the motor (VP)
For head logic (Vdd)
Average:
1.5 A (at 5 V), 2.2 A (at 7.2 V), 2.6 A (at 8.5 V) 2
Maximum:
1.6 A (at 5 V), 2.3 A (at 7.2 V), 2.7 A (at 8.5 V) 2
Maximum 0.46 A
Maximum 0.01 A
1Maximum printing speed is attained with the following conditions:
When the driving voltage is 5 V, the character size is a 24-dot font, the line spacing is 16 dots, the temperature of the
head is 60C or more, and the number of simultaneously activated dots is 64 dots or less
When the driving voltage is 7.2 V, the temperature of the head is 40C or more, and the number of simultaneously
activated dots is 64 dots or less
When the driving voltage is 8.0 V, the temperature of the head is 30C or more, and the number of simultaneously
activated dots is 64 dots or less.
2When the number of simultaneously activated dots is specified as 64.
CHAPTER

3-2
Table 3-1 General Specifications (Continued)
Item Specification
Operating temperature range
-30C to 70C 3
No condensation
Storage temperature range -35C to 75C 3
No condensation
Life span (at 25C and rated energy)
Activation pulse resistance
Abrasion resistance
100 million pulses or more (print ratio=12.5%)
50 km or more
Paper width 58 mm
Paper feeding force 0.49N (50 gf) or more
Paper holding force 0.78N (80 gf) or more
Dimensions (widthdepthheight) 76.8 38.0 16.0 mm (excluding lever)
Mass Approximately 46 g
Recommended thermal paper 5TF50KS-E2D (59 m paper)
from Nippon Paper Industries
TP50KJ-R (65 m paper)
from Nippon Paper Industries
AP50KS-E (65 m paper)
from Nippon Paper Industries
HP220A (65 m paper)
from Mitsubishi Paper Industries
PD160R-N (75 m paper) 4
from Oji Paper Industries
KT55F20 (Normal Thermal Paper)
from Koehler AG
F5041 (75 m paper)
from Mitsubishi Hitec Paper
AF50KS-E (75 m paper)
from Jujo thermal Ltd.
3 Outside this range, prining may blot or be light.
4 When the print ratio is high, this thermal paper may generate a noise during printing.
5 The paper roll should be placed facing the thermal surface outward (See Figure 6-3). Also, do not use paper with edges
that are pasted or have turnups at the start of the roll. If they need to be used unavoidably, replace with new paper roll as
soon as possible before the entire roll is used up.
+0
- 1

3-3
3.2 HEAT ELEMENT DIMENSIONS
The printer contains a thermal head with 384 heat elements (dot-size).
Figure 3-1 Heat Element Dimensions
Figure 3-2 Print Area
48 mm (384 DOTS)
0.125 mm 0.125 mm
58 mm (PAPER WIDTH)
48 mm (PRINTING WIDTH) 5 mm
0.125 mm
(PAPER
FEED
PITCH)
5 mm
+0
-1

3-4
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
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 and then 40 steps in the normal direction during
initialization, a time after backward feeding and a time after setting/releasing the platen block.
During paper feeding, the motor should be driven lower than the value obtained by equation (1).
Equation (1):
Vp 165 - 220 (pps) (max.1000 (pps) )
During printing, the 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.)
Do not print while the motor is rotating in the reverse direction.
Table 3-2 Sample Motor Drive Frequency
Operating Voltage Drive Frequency
(Paper feed)
4.2 V 473 pps
5 V 605 pps
6 V 770 pps
7.2 V 968 pps
8 V 1000 pps
8.5 V 1000 pps

3-5
3.4 STEP MOTOR CHARACTERISTICS
Table 3-3 General Specifications of the Motor
Item Specification
Type PM
Number of phases 4-phase
Drive method Bipolar chopper
Excitation 2-2 phase
Winding resistance per phase 14 10%
Rated voltage 4.2 - 8.5 V
Rated current 0.23 A/phase, 0.15A/phase 1
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.

3-6
3.4.1 Motor Drive Circuit
(1) Sample Drive Circuit
Sample drive circuits for the motor are shown in Figure 3-3.
19
4
5
3.3K
1%
2.7K
1%
0.1F
PC1060-A
2
3
0.1F
1
9
1
11
20
14
13
8
11
3
16
4
2
13
17
14
13
20
11
1
9
4
1
3
2
15
6
1
15
14
7
6
10
12
12 2
3
18
19
6
15
4
5
0.51
1%
1/2W
0.51
1%
1/2W
10F
50V
10F
50V
1K
1%
1K
1%
3K
1%
3K
1%
10K
10K
74HC32
74HC32
NC
NC
0.1F
PH1
Vdd
Vcc
Vdd
Vdd
Vdd
Vdd
Vp
Vp
B
A
B
A
0.01F
10%,10%
1.8K
1%
1SS294
(TE85L,F)
PH2
PH3
PH4
CTCRL
0.01F
10%,10%
0.01F
10%,10%
0.01F
10%,10%
18
3
2
LB1843V-E
LB1843V-E
74HC123A
5
17
9
12
Figure 3-3 Sample Drive Circuit

3-7
(2) Excitation Sequence
As shown in Table 3-4, the printer 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
Figure 3-4 Input Voltage Signals for the Sample Drive Circuit
H
L
H
L
H
L
H
L
A
B
A
B
1 DOT LINE