SII LTP3445 Use and care manual

LTP3445
LINE THERMAL PRINTER MECHANISM
TECHNICAL REFERENCE
39019-2392-02
Seiko Instruments Inc.

LTP3445 TECHNICAL REFERENCE
Document Number 39019-2392-02
First Edition December 1995
Second Edition March 1999
Copyright © 1995,1999 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.

iii
PREFACE
This reference manual describes the specifications and basic operating procedures for the LTP3445 Line
Thermal Printer Mechanism. Chapter 7 describes safety precautions. Read it thoroughly before
designing so that you are able to use the LTP3445 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.

iv

v
TABLE OF CONTENTS
Section Page
CHAPTER 1
FEATURES
CHAPTER 2
SPECIFICATIONS
2.1 GENERAL SPECIFICATIONS.............................................................................................. 2-1
2.2 HEAT ELEMENT DIMENSIONS........................................................................................... 2-4
2.3 PAPER FEED CHARACTERISTICS .................................................................................... 2-5
2.4 STEP MOTOR CHARACTERISTICS. .................................................................................. 2-6
2.4.1 Motor Drive Circuit....................................................................................................2-7
2.4.2 Motor Timing............................................................................................................. 2-9
2.4.3 Precautions for Driving the Motor...........................................................................2-11
2.5 THERMAL HEAD................................................................................................................2-13
2.5.1 Structure of the Thermal Head...............................................................................2-13
2.5.2 Printed Position of the Data.................................................................................... 2-15
2.5.3 Head Resistance.................................................................................................... 2-16
2.5.4 Head Voltage.......................................................................................................... 2-17
2.5.5 Peak Current .......................................................................................................... 2-17
2.5.6 Thermal Head Electrical Characteristics................................................................2-18
2.5.7 Timing Chart........................................................................................................... 2-19
2.6 CONTROLLING THE HEAD ACTIVATION (DST) PULSE WIDTH....................................2-20
2.6.1 Calculation of the Head Activation Pulse Width..................................................... 2-20
2.6.2 Calculation of the Applied Energy..........................................................................2-20
2.6.3 Adjustment of the Head Activation Voltage............................................................ 2-21
2.6.4 Adjustment of the Head Resistance...................................................................... .2-21
2.6.5 Determination of Activation Pause Time and Activation Pulse Period................... 2-22
2.6.6 Head Activation Pulse Term Coefficient................................................................. 2-22
2.6.7 Calculation Sample for the Head Activation Pulse Width. .....................................2-23
2.6.8 Thermistor Resistance. ......................................................................................... .2-24
2.6.9 How to Print Using 2-ply Thermal Paper................................................................ 2-26
2.6.10 Detecting Abnormal Temperature of the Thermal Head........................................2-26
2.7 HEAD-UP DETECTOR. ...................................................................................................... 2-27
2.7.1 General Specifications ........................................................................................... 2-27
2.7.2 Sample External Circuit.......................................................................................... 2-27
2.8 PAPER DETECTOR ........................................................................................................... 2-28
2.8.1 General Specifications ........................................................................................... 2-28
2.8.2 Sample External Circuit.......................................................................................... 2-30
2.8.3 Automatic Paper Load............................................................................................ 2-31

vi
Section Page
CHAPTER 3
CONNECTING EXTERNAL CIRCUITS
3.1 THERMAL HEAD CONTROL FPC....................................................................................... 3-2
3.2 MOTOR/DETECTOR CONNECTOR................................................................................... .3-4
CHAPTER 4
DRIVE METHOD
4.1 THERMAL HEAD DRIVE TIMING....................................................................................... .4-1
4.1.1 In case of executing previous line history control .................................................... 4-1
4.1.2 When previous line history control is not executed.................................................. 4-3
4.2 MOTOR DRIVE TIMING....................................................................................................... 4-5
CHAPTER 5
HOUSING DESIGN GUIDE
5.1 SECURING THE PRINTER.................................................................................................. 5-1
5.1.1 Printer Mounting Method.......................................................................................... 5-1
5.1.2 Precautions for Securing the Printer........................................................................ 5-1
5.2 LAYOUT OF PRINTER AND PAPER................................................................................... 5-2
5.3 WHERE TO MOUNT THE PAPER HOLDER....................................................................... 5-3
5.4 WHERE TO MOUNT THE PAPER CUTTER. ...................................................................... 5-3
5.5 OUTER CASING STRUCTURE. .......................................................................................... 5-4
CHAPTER 6
APPEARANCE AND DIMENSIONS
CHAPTER 7
SAFETY PRECAUTIONS
7.1 DESIGN PRECAUTIONS ................................................................................................... 7-1
7.2 DESIGNING THE OUTER CASE......................................................................................... 7-1
7.3 BATTERY DRIVING..............................................................................................................7-2
CHAPTER 8
DESIGNING AND HANDLING PRECAUTIONS
8.1 DESIGN PRECAUTIONS.. ................................................................................................... 8-1
8.2 HANDLING PRECAUTIONS. ............................................................................................... 8-2
8.3 LOADING/UNLOADING PAPER PRECAUTIONS............................................................... 8-3
8.4 HEAD CLEANING PROCEDURE AND PRECAUTIONS.................................................... .8-5

vii
TABLES
Table Page
2-1 General Specifications ........................................................................................................ 2-1
2-2 Sample Motor Drive Frequency...........................................................................................2-5
2-3 General Motor Specifications.............................................................................................. 2-6
2-4 Excitation Sequence............................................................................................................ 2-8
2-5 Acceleration Steps ............................................................................................................ 2-12
2-6 Blocks and Activated Heat Element.................................................................................. 2-15
2-7 Head Resistance Ranks.................................................................................................... 2-16
2-8 Head Voltage..................................................................................................................... 2-17
2-9 Thermal Head Electrical Characteristics (at Vdd=5 V, 25°C). .......................................... 2-18
2-10 Activation Pulse Width....................................................................................................... 2-23
2-11 Temperature and Corresponding Thermistor Resistance................................................. 2-25
2-12 Absolute Maximum Ratings of the Paper Detector (at 25°C)............................................ 2-28
2-13 Paper Detector Input/Output Conditions...........................................................................2-29
3-1 Recommended Connectors................................................................................................. 3-1
3-2 Thermal Head Control Terminal Assignments................................................................... .3-3
3-3 Terminal Assignments of the Motor/Detector Connector....................................................3-4
FIGURES
Figure Page
2-1 Heat Element Dimensions................................................................................................... 2-4
2-2 Print Area............................................................................................................................. 2-4
2-3 Sample Drive Circuit (Motor)............................................................................................... 2-7
2-4 Input Voltage Signals for the Sample Drive Circuit (Motor) ................................................ 2-8
2-5 Motor Start/Stop Timing ......................................................................................................2-9
2-6 Motor Drive Timing Chart.................................................................................................. 2-11
2-7 Thermal Head Block Diagram........................................................................................... 2-14
2-8 Printed Position of the Data............................................................................................... 2-15
2-9 Timing Chart...................................................................................................................... 2-19
2-10 Thermistor Resistance vs. Temperature........................................................................... 2-24
2-11 How to Drive 2-ply Thermal Paper.................................................................................... 2-26
2-12 Sample External Circuit for the Head-Up Detector ........................................................... 2-27
2-13 Sample External Circuit of the Paper Detector. ............................................................... .2-30
2-14 Flowchart for Automatic Paper Load................................................................................. 2-31
3-1 Thermal Head Control Terminals (FPW)............................................................................. 3-2
3-2 Terminals on the Motor/Detector Connector....................................................................... 3-4
4-1 Example of timing chart when executing previous line history control................................ 4-2
4-2 Example of timing chart when not executing previous line history control.......................... 4-4

viii
Figure Page
4-3 Example of motor drive timing chart in “High speed print mode”........................................ 4-6
4-4 Example of motor drive timing chart in “Standard print mode”. .......................................... 4-8
5-1 Curled Path. ........................................................................................................................ 5-2
5-2 Straight Path........................................................................................................................ 5-2
5-3 Sample Outer Casing Structure.......................................................................................... 5-4
6-1 LTP 3445 Appearance and External Dimensions............................................................... 6-2
8-1 Guide Design Example ....................................................................................................... 8-4
8-1 Head Cleaning Procedure................................................................................................... 8-5

1-1
CHAPTER 1
FEATURES
The LTP3445 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 LTP3445 Line Thermal Printer Mechanism can be driven by battery, it can easily be mounted
on a portable device such as a hand-held terminal.
The LTP3445 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 you can use four through six Ni-Cd batteries or Ni-MH
batteries. You can also use two Lithium-ion batteries.
•Compact and light
The mechanism is compact and light: 130 mm in width, 51 mm in depth, 21 mm in height, and
approximately 135 g in weight.
•High resolution printing
A high-density print head of 8 dots/mm produces clear and precise printing.
•Long life
The mechanism is maintenance-free device with a long life of 50 km print length or 50 million pulses.
•High speed printing 1
A maximum print speed of 160 dot lines per second (20 mm per second) at 5 V, and 400 dot lines
per second (50 mm per second) at 7.2 V is attainable.
•High quality printing
A history control IC produces high quality printing.
•Low current consumption
The printer can be driven by lithium-ion batteries of low discharge current.
•Compatible with thick paper 2
There are two possible paper paths; with the straight path, printing on thick paper is possible.
•Low noise
Thermal line dot printing is used to guarantee low-noise printing.

1-2
•Automatic paper load
A paper detector enables the LTP3445 to load paper automatically.
•Thermal head cleaning
Moving the head open lever to the open position enables one to clean the thermal head.
1Print speed differs depending on working conditions.
2Paper load path (curl or straight) is preset at the factory. To determine which path is used, contact a Seiko Instruments
sales representative.

2-1
CHAPTER 2
SPECIFICATIONS
2.1 GENERAL SPECIFICATIONS
Table 2-1 General Specifications
Item Specification
Print method Thermal dot line printing
Dots per line 832 dots
Resolution 8 dots/mm
Print width 104 mm
Maximum print speed 160 dot lines/sec (20 mm/sec) (at 5 V) 1
400 dot lines/sec (50 mm/sec) (at 7.2 V) 1
Paper feed pitch 0.125 mm
Head temperature detection Via a thermistor
Head-up detection Via a mechanical switch
Out-of-paper detection Via a photo interrupter
Operating voltage range
VPline (for head and motor drive)
Vdd line (for head logic)
4.2 V to 8.5 V
(equivalent to four through six Ni-Cd or Ni-MH
batteries, or two lithium-ion batteries)
4.5 V to 5.5 V
1Maximum print speed is attained in the conditions such as:
•When the driving voltage is 5 V, the temperature of the head is 50°C or more, and the number of simultaneously
activated dots is 64 or less
•When the driving voltage is 7.2 V, the temperature of the head is 20°C or more, and the number of simultaneously
activated dots is 64 or less

2-2
Table 2-1 General Specifications (Continued)
Item Specification
Current consumption
For driving the head (VP)
For driving the motor (VP)
For head logic (Vdd)
Average 1.7 A (at 5 V), 2.5 A (at 7.2 V) 2
Maximum 1.9 A (at 5 V), 2.8 A (at 7.2 V)2
Maximum 0.6 A
Maximum 0.026 A
Operating temperature range 0°to 50°C 3, 4
Storage temperature range -20°to 60°C
Life span (at 25°C and rated energy)
Activation pulse resistance
Abrasion resistance
50 million pulses or more
(print ratio=12.5%) 5
50 km or more
Paper width 112 -1 mm
Paper feed force 50 g or more
Paper hold force 80 g or more
Dimensions (width ×depth ×height) 130.0 ×51.0 ×21.0 mm
Weight Approximately 135 g
2When the number of simultaneously activated dots is specified as 64.
3Use TW80KK-S in the temperature range 5°to 4°C. Outside of this range, the print will bleed or be light.
4Use TCC in the temperture range 5°to 35°C. Outside of this range, the print will bleed or be light.
5In the case of using 2-ply thermal paper, the printing pulse is 2 pulse /1 dot, and so 50 million pulses
means 25 million dot lines.
+
0

2-3
Table 2-1 General Specifications (Continued)
Item Specification
Recommended thermal paper TF50KS-E2C (65 µm paper)
TF77KS-E2 (95 µm paper)
TC98KS-T1 (125 µm paper)
J & N tack HW74 (label paper)
TW80KK-S (2-ply paper)
from Nippon Paper Industries
FH65BV-3 (65 µm paper)
from Honshu Paper Co., Ltd.
TCC (2-ply paper)
from Fujicopian Co., Ltd.

2-4
2.2 HEAT ELEMENT DIMENSIONS
The LTP3445 contains a thermal head with 832 heat elements (dot-size).
Figure 2-1 Heat Element Dimensions
104 mm (832 DOTS)
0.125 mm 0.125 mm
Figure 2-2 Print Area
112 -1 mm (PAPER WIDTH)
104 mm (PRINTING WIDTH) 4 mm
0.125 mm
(PAPER
FEED
PITCH)
4 mm
+0

2-5
2.3 PAPER FEED CHARACTERISTICS
•Paper is fed in the forward direction when the motor shaft is rotating in the normal direction
(clockwise) as 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 print quality due to backlash of the paper feed system, the motor should
be driven 40 steps in the reverse direction then 40 steps in the normal direction during initialization
or after backward feeding.
•During paper feed, the motor should be driven at lower than the value obtained by equation (1).
Equation 1:
7.2 V or more : Vp ×77 + 245.6 (pps)
Less than 7.2 V: Vp ×160 - 352 (pps)
•During printing, motor drive frequency should be adjusted according to the working conditions such
as voltage, temperature, number of activated dots, etc. (For details, see Chapter 4.)
•To automatically load paper, the motor should be driven at lower than a quater of the value obtained
by equation (1).
•It is not possible to print while the motor is rotating in the reverse direction.
Table 2-2 Sample Motor Drive Frequency
Operating Voltage Drive Frequency
(Paper feed)
Drive Frequency
(Automatically loading
paper)
4.2 V 320 pps 80 pps
5 V 448 pps 112 pps
6 V 608 pps 152 pps
7.2 V 800 pps 200 pps
8 V 862 pps 215 pps
8.5 V 900 pps 225 pps

2-6
2.4 STEP MOTOR CHARACTERISTICS
Table 2-3 General Motor Specifications
Item Specification
Type PM
Number of phases 4-phase
Drive method Bipolar
Excitation 2-2 phase
Winding resistance per phase 11 Ω±7%
Rated voltage 4.2 - 8.5 V
Rated current 0.3 A / phase
Maximum current consumption 0.6 A
Drive frequency 50 - 900 pps
(according to drive voltage)

2-7
2.4.1 Motor Drive Circuit
(1) Sample Drive Circuit
A sample drive circuit for the motor is shown in Figure 2-3.
Figure 2-3 Sample Drive Circuit (Motor)

2-8
(2) Excitation Sequence
As shown in Table 2-4, the LTP3445 feeds the 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
the reverse direction, drive the motor in the reverse order: step 4, step 3, step 2, step 1, step 4, step 3, . .
Sequence
Signal Name
Step 1 Step 2 Step 3 Step 4
ALow High High Low
BHigh High Low Low
AHigh Low Low High
BLow Low High High
Figure 2-4 Input Voltage Signals for the Sample Drive Circuit (Motor)
H
L
H
L
LL
L
H
L
H
L
A
B
A
B
1 DOT LINE
Table 2-4 Excitation Sequence

2-9
2.4.2 Motor Timing
Refer to the time chart in Figure 2-5 when designing the control circuit or software for starting and
stopping the motor. Also note 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 the same phase as the last one in the printing
step.
(2) Pause state
•In the pause state, do not excite the step motor so as to prevent the motor from heating. Even
when the step motor is not excited, it keeps holding force to prevent paper from sliding.
(3) Start step
•To restart the motor from the stop step, immediately shift the motor into the print sequence.
•To restart the motor from the pause (no excitation) state, shift the motor into the print sequence
after outputting the same phase as that of the stop step for a single step.
Figure 2-5 Motor Start/Stop Timing
1 DOT LINE
STOP
STEP
M2
M1
PRINT STEP PRINT STEP
H
L
H
L
H
L
H
L
PAUSE
STATE START
STEP
M3
M4