| 摘要 |
PURPOSE:To fix the period of a driving signal and fix velocities of a recording paper and an ink sheet, by providing a thermal pulse correcting part by which the period of a thermal pulse signal generated from a thermal pulse generating part is fixed when the temperature of a thermal head reaches or exceeds a predetermined value. CONSTITUTION:The thermal pulse correcting part comprises a microcomputer 4, a timer part 7 and a pulse width setting part 5, and the microcomputer 4 comprises a speed-controlling part for outputting to a driving means 6 a driving signal synchronous with a thermal pulse signal and a correcting thermal pulse signal. As the temperature of the thermal head 1 is raised, the head 1 is heated by a thermal pulse signal with a small width supplied from the microcomputer 4, and until the temperature reaches a predetermined value, the period of the driving signal from the microcomputer 4 is short, so that the speed of the driving means 6 is high. Even when the temperature of the head 1 reaches or exceeds the predetermined temperature, the period of the driving signal is constant, so that the speed of the driving means 6 is fixed. |
