Seiko LTPA245 Series User manual

LTPA245 SERIES
LINE THERMAL PRINTER MECHANISM
TECHNICAL REFERENCE
U00060425801

LTPA245 SERIES TECHNICAL REFERENCE
Document Number U00060425801
First Edition June 2001
Second Edition July 2003
Copyright © 2001, 2003 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 LTPA245
Series Line Thermal Printer Mechanisms (hereinafter referred to as “LTPA245” or “printer”).
The LTPA245 consists of the following four printer models, which differ by the shape of the lever for
removing/installing the platen block, the shape of FPC (Flexible Printed Circuit) and so on:
!LTPA245A
!LTPA245B
!LTPA245C
!LTPA245D
This technical reference, unless otherwise specified, provides information common to the LTPA245 series
printers. Where the information differs depending on the printer model, the name of the relevant model is
specified.
Chapter 1 “Precautions” describes safety, design and operational precautions. Read it thoroughly before
designing in order to ensure proper use of the printer.
SII has not investigated the intellectual property rights related to the sample circuits included in this
technical reference. Fully investigate the intellectual property rights related to these circuits before use.
Moreover, when designing any circuit based on the sample circuits described in this reference manual,
use such circuit only after careful verification.

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
This printer has no platen position detector. Attach a detector to the outer case to monitor
whether or not the platen block is properly secured. Also, design the product so that the
thermal head is not driven when the platen block is open.
Warn the user not to touch the thermal head or its periphery as they are very hot during and
immediately after printing.
Also, allow cooling by designing clearance between the head and the outer case.
!Preventing the user from touching the motor
Design the outer case so that the user cannot touch the motor as the motor are very hot
during and immediately after operating.
Also, allow cooling by designing clearance between the motor and the outer case.
Drive the motor within the continuous drive time and pause time described in Section 3.4.3.
!Preventing the user from touching the rotary drive portion
This printer has no platen position detector. Attach a detector to the outer case to monitor
whether or not the platen block is properly set. Also, design the product so that the motor
does not operate when the platen block is open, to prevent the user from getting caught in the
motor because the drive gear is exposed.
!Preventing the user from touching the sharp edges of the printer
Design the product so that during handling the user cannot touch the edges of the printer,
particularly the cut surfaces of metal parts because of the risk of injury. Implement a design
that prevents such contact, or provide ample warnings.
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
!This technical reference provides the LTPA245 specifications and basic drive method. The
specifications are assured under the recommended drive circuit, drive method, and
installation. If damage occurs by using any method other than the described herein, we are
not responsible for such damage.
!This technical reference, unless otherwise specified, provides information common to the
LTPA245 series printers. Where the information differs depending on the printer model, the
name of the relevant model is specified.
!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.
!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 FG plate as shown in Figure 6-2 to the Frame Ground (FG). For details on how
to mount an FG cable, see Section 6.1.2. The FG cable and FG cable lock screw
should be prepared in advance.
!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.
!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: 10$F Aluminum electrolytic capacitor
Vdd #GND: 0.1$F Laminated ceramic capacitor
!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 %2) Vp
At power OFF: 1) Vp %2) Vdd

1-3
!Always monitor the output of the paper detector. Incorrect activation of the thermal head may
damage and reduce the longevity of the thermal head and the platen.
Since a reflection type photo interrupter is used in the paper detector, the detector may be
affected by light from outside. Design the outer case so that the paper detector is not
affected by light from outside.
!Allow for movement of the FPC when designing the outer case because the FPC connected
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.
!Since this printer does not have a platen position detector, mount a detector to the outer case
to monitor whether or not the platen is properly set. When the platen is not properly set, the
printer cannot feed paper and print normally. Incorrect setting of the thermal head may reduce
the longevity of the thermal head.
!When using the LTPA245A:
The printer has no platen block support function. For the platen block support, prepare the
plastic (poly-carbonate is recommended) platen support for snap fitting in the paper holder
cover and fit the platen block shaft into it. For the dimensions of the platen support, the platen
block positioning, and securing, follow the instructions shown in Figures 6-4 and 6-5. Metal or
aluminum platen support cannot fit the platen block shaft.
!When using the LTPA245A:
When removing the platen block, follow the instructions shown in Figure 7-4 and continue to
press the lock arm lever until the A portion of the lock arm (see Figure 7-4) comes up against
the head block. If the lock arm lever is not pressed until the end, it may not be possible to
remove the platen block. Design the outer case so that such lock arm lever operation can be
performed.
Regarding the center of the
rotation of the paper holder cover
on which the platen block is
mounted, follow the instructions
shown in Figure 7-1.
Platen support:
Prepare the plastic (poly-carbonate is
recommended) platen support for snap
fitting in the paper holder cover and fit
the platen block shaft into it. For the
dimensions of the platen support, the
platen block positioning, and securing,
follow the instructions shown in Figures
6-4 and 6-5.
Design so that the paper feed
load is 0.49N (50 gf) or less.
The lever of the lock arm should
be used when removing the
platen block. It should never be
pulled up by force.
Since the printer mechanism
does not have a function to
prevent paper from sliding,
design the outer case so that
the paper is guarded securely.

1-4
!When using the LTPA245B and LTPA245C:
The printer does not have a platen block support function. Prepare the paper holder cover
and fix the platen block to the cover. For the dimensions for mounting the platen block, see
Figure 6-6.
Since the printer
mechanism does not
have a function to prevent
paper from sliding, design
the outer case so that the
paper is guarded
securel
y
.
Platen block
Prepare the paper holder cover and
mount the platen block to the paper
holder cover for the platen block
support. For the fixing position and
dimensions, see Figure 6-6.
The platen block should be pulled up
while the lock arm lever is pressed to
the Open state, to remove the platen
block. It should never be pulled up by
force without lever operation.
Design so that the paper feed
load is 0.49N (50 gf) or less.

1-5
!When using the LTPA245D:
The printer does not have a platen block support function. Prepare the paper holder cover
and fix the platen block to the cover. For the dimensions for mounting the platen block, see
Figure 6-6.
When removing the platen block, follow the instructions shown in Figure 7-4 and continue to
press the lock arm lever until the A portion of the lock arm (see Figure 7-4) comes up against
the head block. If the lock arm lever is not pressed until the end, it may not be possible to
remove the platen block. Design the outer case so that such lock arm lever operation can be
performed.
1.2.2
Since the printer
mechanism does not
have a function to
prevent paper from
sliding, design the outer
case so that the paper is
g
uarded securel
y
.
Platen block
Prepare the paper holder cover and
mount the platen block to the paper
holder cover for the platen block
support. For the fixing position and
dimensions, see Figure 6-6.
The platen block should be pulled up
while the lock arm lever is pressed to the
Open state, to remove the platen block.
It should never be pulled up by force
without lever operation.
Design so that the paper feed
load is 0.49N (50 gf) or less.

1-6
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 (FPC): Doing so may damage the
FPC.
!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. Also, incorrect paper feed puts a load on the reduction gear and may shorten
the longevity of the 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 Vp 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.

1-7
1.2.3 Precautions on Discarding
When discarding used printers, discard them according to disposal regulations and rules of each
respective district.

2-1
2
FEATURES
The LTPA245 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 be battery driven, it can easily be mounted onto a
portable device such as a hand-held terminal.
The LTPA245 has the following features:
!Battery drive
Since the range of operating voltage of 4.5V 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: 69.2 mm in width, 28.3 mm in depth, 31.7 mm in
height, and approximately 41 g (LTPA245A) and 43 g (LTPA245B, LTPA245C, and
LTPA245D) in mass.
!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 427 dot lines per second (53.4 mm per second) at 5 V, 616 dot
lines per second (77 mm per second) at 7.2 V, and 720 dot lines per second (90 mm per
second) at 8.5 V are attainable.
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 of the lock arm and the platen block.
41 g in mass 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 ×16 dots/mm (W ×H)
Print width 48 mm
Maximum printing speed 427 dot lines/s (53.4 mm/s) (at 5 V) 1
616 dot lines/s (77 mm/s) (at 7.2 V) 1
720 dot lines/s (90 mm/s) (at 8.5 V) 1
Paper feed pitch 0.0625 mm
Head temperature detection Via thermistor
Out-of-paper detection Via photo interrupter
Operating voltage range
VPline (for head and motor drive)
Vdd line (for head logic)
4.5 V to 8.5 V
(equivalent to four through six Ni-Cd or Ni-MH
batteries, or two lithium-ion batteries)
2.7 V to 5.25 V
Current consumption
For driving the head (VP)
For driving the motor (VP)
For head logic (Vdd)
Average:
1.48 A (at 5 V), 2.13 A (at 7.2 V), 2.51 A (at 8.5 V) 2
Maximum:
1.53 A (at 5 V), 2.20 A (at 7.2 V), 2.60 A (at 8.5 V) 2
Maximum 0.60 A
Maximum 54 mA
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 50°C or more, the number of simultaneously activated dots is 64 dots or less and the head division
driving is not performed.
!When the driving voltage is 7.2 V, the temperature of the head is 10°C or more, the number of simultaneously
activated dots is 64 dots or less and the head division driving is not performed.
!When the driving voltage is 8.5 V, the number of simultaneously activated dots is 64 dots or less and the head
division driving is not performed.
2When the number of simultaneously activated dots in the head is specified as 64.
CHAPTER

3-2
Table 3-1 General Specifications (Continued)
Item Specification
Operating temperature range 0°C to 50°C 3
No condensation
Storage temperature range -25°C to 70°C 3
No condensation
Longevity (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) 69.2 ×28.3 ×31.7 mm (excluding lever of lock arm
and platen block)
Mass Approximately 41 g (LTPA245A), 43 g (LTPA245B,
LTPA245C, and LTPA245D )
Recommended thermal paper 4TF50KS-E2D (59 µm paper)
from Nippon Paper Industries Co.,Ltd.
3Outside this range, prining may blot or be light.
4The paper roll should be placed facing the thermal surface outward (See Figure 6-6). 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
5 mm
48 mm (384 DOTS)
0.125 mm 0.125 mm
0.0625 mm
58 mm (PAPER WIDTH)
48 mm (PRINTING WIDTH) 5 mm
0.062 mm
(PAPER
FEED
PITCH)
+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
(anticlockwise) when seen from the motor gear side.
!The motor is driven by a 2-2 phase excitation, constant current chopper method and feeds
paper 0.0625 mm (equivalent to 0.5 dot pitch) every one step of the motor drive signal.
!To prevent deterioration in printing quality due to backlash of the paper feed system, the motor
should be rotated 20 steps anticlockwise (the backlash absorption step should be input) when
seen from the motor gear side, after initialization, after opening or closing the platen block, or
after cutting thermal paper with the autocutter or tear bar (hand cutter). Be sure to start printing
after such operation.
!During paper feeding, the motor should be driven lower than the value obtained by equation (1)
and (2).
Equation (1):
Vp > 5.5 V
Vp ×160 + 80 (pps)
(Max. 1440 (pps))
Equation (2):
Vp ≤5.5 V
Vp ×210 - 195 (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 rotate the motor anticlockwise when seen from the motor gear side.
Table 3-2 Sample Motor Drive Frequency
Operating
Voltage
Drive Frequency
(Paper feed)
Motor Pulse Width Feed Speed
4.5 V 750 pps 1333.3 µs 46.9 mm/s
5 V 855 pps 1169.6 µs 53.4 mm/s
6 V 1040 pps 961.5 µs 65 mm/s
7.2 V 1232 pps 811.7 µs 77 mm/s
8 V 1360 pps 735.3 µs 85 mm/s
8.5 V 1440 pps 694.4 µs 90 mm/s

3-5
3.4 STEP MOTOR CHARACTERISTICS
Table 3-3 General Specifications of the Motor
Item Specification
Type PM
Drive method Bipolar chopper
Excitation 2-2 phase
Winding resistance per phase 14 Ω±10%
Rated voltage 4.5 - 8.5 V
Rated current 0.30 A/phase
Maximum current consumption 0.60 A
Drive frequency 200 - 1440 pps (according to drive voltage)

3-6
3.4.1 Motor Drive Circuit
(1) Sample Drive Circuit
Sample drive circuit for the motor is shown in Figure 3-3.
Figure 3-3 Sample Drive Circuit
Vdd
Vdd
Vdd
Vdd
Vdd
Vdd
10V,
10V,
10V,
10V,

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, . . . . Do not feed paper in the
reverse direction.
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

3-8
3.4.2 Motor Timing
Refer to the timing chart in Figure 3-5 when designing the control circuit and/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 5 ms with a phase that is the same as the final one in the printing
step.
(2) Pause state
!In the pause state, do not excite the step motor to prevent the motor from overheating. 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, 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 for 5 ms a phase that is the same as that of the stop step.
Figure 3-5 Motor Start/Stop Timing
STOP
STEP
PH2
PH1
PRINT STEP PRINT STEP
H
L
L
H
H
L
L
H
PAUSE
STATE
START
STEP
PH3
PH4
1 DOT LINE