| 摘要 |
<p>PURPOSE:To provide the title protection circuit controlling the output period of a strobe signal on the basis of a non-stabilized heating voltage level. CONSTITUTION:The protection circuit of a thermal head applying non-stabilized heating voltage to the heating element corresponding to printing data during the output period of a strobe signal is equipped with a time constant circuit 2 composed of a series circuit of a condenser C wherein an input strobe signal is applied to one electrode and a resistor R wherein non-stabilized voltage Vh is applied to one terminal, the Zener diode D connected to the connection point of the condenser C and the resistor R and a comparison circuit 1 comparing the level of the voltage Vt at the connection point with the level of reference voltage V and the output of the comparison circuit 1 is set to a strobe signal.</p> |
