| 摘要 |
<p>PURPOSE:To allow malfunction not to be generated in starting, by a method wherein a voltage conversion circuit to which output of an operation DC power source of a heating resistor is applied, is established, and the output of said voltage conversion circuit is supplied at least, to an enable signal control circuit in a driving circuit. CONSTITUTION:A resistor heating control enable signal sent out from a central processor is generated with a monostable multivibrator in a driving circuit 16, and is applied to a control circuit 17. An operational DC of the control circuit 17 is obtained by converting voltage from a DC power source 12 with a voltage conversion circuit 14. Only when both DC power sources 12, 13 normally rise in closing a power source of a thermal line printer and the voltage conversion circuit 14 normally starts to be operated, the enable signal is transmitted t a thermal head 15. Even if only the DC power source rises, when the control circuit is not operated, the enable signal can not be transmitted normally to the thermal head. Therefore, the thermal head 15 can not perform printing operation. Accordingly, a malfunction of the thermal head can be prevented.</p> |
