Brother PT-9200PC, Service Manual, Page: 73 / 93

III - 10
3.2.7 Thermal Head Control Circuit
Figs. 3.2-7 and 3.2-8 show the thermal head control circuit and the thermal head
drive timing chart, respectively.
The thermal head uses a 384-dot (360 dpi) edge head and incorporates four 96-dot
driver ICs. Serial data is transferred to the four drivers in synchronization with the
clock signal. Print data is output in synchronization with the 3.685 MHz clock (a
quarter of 14.74 MHz).
In response to the LATCH signal from P62 of the CPU, the head driver circuit
latches the print data to synchronize it with the STB signal from P80, driving the
specified heating elements.
The method of controlling the thermal head is as follows.
Fig. 3.2-7 Thermal Head Control Circuit
Fig. 3.2-8 Thermal Head Drive Timing Chart