| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily secure a high temperature region suitable for printing/erasing by providing a preheating means that preheats a thermal head every prescribed time period. SOLUTION: On a thermal head 12, multiple heating resisters 21... are provided on an overall head face at prescribed intervals and preheating resisters 22... are provided between the respective heating resisters 21.... When a power us turned on, each of the heating resisters 21... is heated to an operation temperature. A current is controlled to be applied to each of the preheating resisters in accordance with a preheating signal so that each is heated to an optimum preheating temperature. That is, a CPU outputs the preheating signal to control the current to each of the preheating resisters. In terms of the preheating signal at that time, a pulse signal having ON and OFF states is outputted so that the preheating resister is preheated every prescribed time interval. The current value to the preheating resister 22 is adjusted corresponding to the resistance value R of the resister 22. As a result, a heating temperature range becomes small, thereby readily obtaining a heating quantity suitable for printing/erasing.</p> |
