Seiko LTP1245R-C384-E, Техническое описание, Страница: 50 / 74

5-2
5.2 MOTOR DRIVE TIMING
The phase of motors and the thermal head need to be synchronized to print.
As example, the print method which divides one dot line to two groups; the blocks 1,3, and 5 and the
blocks 2,4, and 6, and prints each group data for each step of the motor is described below.
Basic pulse width of the motor drive pulse, Tm, is a value (unit: msec) of the reciprocal number of the
driving frequency calculated using equation (1) of
"3.3 PAPER FEED CHARACTERISTICS" .
Pause State
Transfer the print data to the thermal head according to " 5.1 THERMAL HEAD DRIVE TIMING ".
Start up phase
Excite the phase which is output just before the motor stops for the time of the start up in
Table 3-5 .
1st line, 1st step
Drive the motor by one step (1st step). The step time should be the acceleration 1st step time or
Tm, whichever is longer.
Set DST for the blocks 1, 3, and 5 to “High” in synchronization with the motor drive.
After setting DST to “High”, set DST to “Low” when the driving time calculated in
“3.6 CONTROLLING THE HEAD ACTIVATION (DST) PULSE WIDTH” has passed.
Move to the 2nd step after the transfer of print data for the blocks 1, 3 and 5 and the 1st step time
of the motor.
1st line, 2nd step
Drive the motor by one step (2nd step). As to how much step time is output, compare Tm with the
time that was taken in the previous step.
(1) In case Tm < the time that was taken in the previous step,
the next closest acceleration step time to the previous step time or Tm, which is longer, is
output.
(2) in case Tm > the time that was taken in the previous step,
the closest acceleration step time to Tm and the acceleration step time that is larger than Tm,
are output.
Set DST for blocks 2, 4, and 6 to “High” in synchronization with the motor drive. After setting DST
to “High”, set DST to “Low” after completion of the head activation time. Transfer the print data of
the next dot line to the thermal head after completion of printing for blocks 2, 4, and 6.
Move to the 2nd dot line after completion of the 2nd step time of the motor and the transfer of print
data for the next dot line.