2-20
2.6 CONTROLLING THE HEAD ACTIVATION (DST) PULSE WIDTH
2.6.1 Calculation of the Head Activation Pulse Width
The LTP3445 is provided with a preline history control function, allowing the preheat pulse to be applied
to the nonactivated element on the preceding dot line before the main heat pulse. For actual drive
method, refer to Section 4, “DRIVE METHOD”.
The head activation pulse width is calculated using the following equation (3).
To execute high quality printing using the LTP3445, the value that is calculated using the following
equation (3) must be adjusted according to the printer installation environment. Calculate each value
used according to the steps in Sections 2.6.2 to 2.6.6 and control so that the pulse width with the tm (ts)
value obtained by substituting each value into the equation (3).
Printing using too high of voltage or too long of pulse width may shorten the life of the thermal head.
Equation 3:
t
m
: Main heat pulse width (ms)
t
s
: Preheat pulse width (ms)
E
: Standard applied energy (mj)
Refer to section 2.6.2.
V : Applied voltage (V)
Refer to section 2.6.3.
R : Head resistance (
Ω
)
Refer to section 2.6.4.
C
m
: Main heat pulse term coefficient
Refer to section 2.6.6.
C
s
: Preheat pulse term coefficient
Refer to section 2.6.6.
2.6.2 Calculation of the Applied Energy
The applied energy should be according to the temperature of the thermal head and the printer
installation environment
The thermal head has a built-in thermistor. Measure the temperature using the thermistor resistance. The
standard applied energy is based on using the recommended thermal paper (65
µ
m) and a temperature of
25
°
C. Calculate the printing energy using equation (6) and the paper coefficient and temperature
coefficient.
Equation 6:
T
X
: Detected temperature using the thermistor (
°
C)
1
P : Thermal paper coefficient
TF50KS-E2C (65
µ
m paper)
1.0
FH65BV-3 (65
µ
m paper)
1.0
TF77KS-E2 (95
µ
m paper)
1.0
E
×
R
t
X
=
×
Cm (Cs)
V
2
E = (0.32 - T
C
(T
X
- 25) )
×
P
Summary of Contents for LTP3445
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