Seiko LTP F Series, Reference Manual

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3-14
3.5 THERMAL HEAD
The thermal head consists of heat elements and a head driver which drives and controls the heat
element.
Serial print data input from the DAT IN terminal is transferred to the shift register synchronously with
the CLK signal, then stored in the latch register at the timing of the LATCH signal.
Input of the head print activation signal (DST1, 2) activates the heat elements in accordance with the
print data stored in the latch register.
The LTP F series can be printed by dividing printing into blocks for every 128 dots.
The divided printing is effective for a high print ratio printing because the peak current can be cut down
with the reduction of the average print speed.
When printing is performed using division into blocks of less than 128 dots, messy printing and/or
abnormal sound may occur, and the printing quality may deteriorate remarkably. Check the number of
dots in advance.
Also, when a pattern with a high print ratio is printed with less than 176 dots, a printing failure may
occur due to the printing paper getting stuck depending on the ambient temperature, drive voltage and
the thermal paper that is used.
When using a high-print ratio pattern, check the number of dots in advance.