LTPH245 datasheet(49/64 Pages) SII

49 / 64 page

5-2

5.2

MOTOR DRIVE TIMING

To print, the phase of motors need to be synchronized with that of the thermal head.

As example, the print method which divides one dot line to two groups; the block 1,3, and 5 and the

block 2,4, and 6, and prints each group data for each step of the motor is described below.

The 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 step

shown 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 block 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 completion of the 1st step time of the motor and the activation of

blocks 1, 3, 5.

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.

LTPH245 Datasheet(PDF) 49 Page - Seiko Instruments Inc