| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent overheating of each heat generating element of a thermal head. SOLUTION: This counter 27 counts an output time of an 'L' original enable signal outputted from a thermal head control part 25, and outputs an 'L' when the counted time is within a standard time. An enable signal with the same pulse width as the original enable signal is outputted from an OR gate 28. When the original enable signal remains outputted continuously due to failure of the thermal head control part 25, the counted time exceeds the standard time. At the time, an 'H' stopping signal is outputted from the counter 27 so that an enable signal is not outputted from the OR gate 28. Thereby, electric power supply to a heat generating element is stopped in a thermal head 14.</p> |
