| 摘要 |
<p>PURPOSE: To realize the stable limitation of the energizing pulse width of a printing head to below a predetermined width even when a trouble occurs in a controlling part by a method wherein an oscillating means for actuating a printing controlling means and a protecting means is provided apart from the oscillating means provided in the controlling part. CONSTITUTION: Strobe prompting signal STB (a) is outputted from a printing controlling part 17 so as to state the counting action of a counter CT through an inverter INV. At the same time, a real strobe signal (d), which acts as the energizing timing signal of a thermal head 20, is outputted from a NAND gate NAND to a head driver 19. In this case, when the counted value of the counter CT controlled by the clock pulse CLK sent from a transmitter 18a exceeds the maximum energizing limiting time A, which is set in advance, of the thermal head 20, a counter carrier C is outputted, resulting in forcibly stopping the supply of the real strobe signal (d) and releasing the energizingly driving of the thermal head 20.</p> |
