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1.2 DESIGN AND HANDLING PRECAUTIONS
To maintain the primary performance of the printer and to prevent future problems from occurring, follow the
precautions below.
1.2.1 Design
Precautions
•
Apply power in the following manner:
At power on : 1) V
dd
→
2)
V
P
At shut down : 1)
V
P
→
2)
V
dd
•
When turning the power on or off, or during not printing, always disable the DST terminals.
•
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 shown in Chapter 3 “CONTROLLING THE
ACTIVATION PULSE WIDTH FOR THERMAL HEAD”.
•
Use C-MOS IC chips for CLK,
LAT
, DI and DST signals of the thermal head.
•
To prevent the thermal head from being damaged by static electricity:
1) Connect on the printer main body and the platen block to the Frame Ground (FG) of the
outer case. See Chapter 6 “OUTER CASE DESIGN GUIDE” for details.
2) Connect the GND terminal (SG) to FG through approximately 1 M
Ω
resistance.
•
Keep the
V
P
power off while not printing in order to prevent the thermal head from electrolytic
corrosion. In addition, design the product so that the signal GND of the thermal head and the frame
GND of the printer become the same electric potential.
•
Make the wire resistance between the power supply (
V
P
and GND) and the printer (connecting
terminals) as small as possible (below 50m
Ω
). Keep distance from signal lines to reduce electrical
interference.
•
A surge voltage between
V
P
and GND should not exceed 10V.
•
For noise countermeasure, connect a 0.1
μ
F capacitor between V
dd
and GND pins near the
connector.
•
Always detect the outputs of the platen position sensor and out-of-paper sensor. Never activate the
thermal head when the platen block is in open state and when there is no thermal paper. Incorrect
activation of the thermal head may reduce the life of the thermal head and the platen and may
damage them.
•
Design the product so that a tension force is not applied to the FPC. The FPC could be moved by
setting/releasing the platen block, so design the product so that the FPC has enough play after
connected it. The tension force may cause some print problems and may damage the FPC.
•
A pause time between thermal head activations of the same heat element shall be secured more than
0.5ms. Pay attention to when using one division printing or when a thermal head activation time
becomes longer. If activating for a long time without the pause time, the thermal head may become
damaged.
•
Noise and vibration during printing vary depending on the motor pulse rate. Verify the performance
with your actual device.
•
Paper feed force can be decreased depending on the motor pulse rate. Verify the performance with
your actual device.
•
Do not perform continuous printing to prevent the motor from overheating. Refer to Chapter 3
“Motor Drive Method” to set a pause time.
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