| 摘要 |
PURPOSE:To enable printed density to be controlled by a simple power source circuit, by providing a circuit for outputting a pulse with a period prescribed by a variable means, and a power source controlling means for stopping the supply of electric power to a thermal head when the counted number of pulses inputted from the pulse generating circuit into a controlling circuit reaches a predetermined value. CONSTITUTION:The controlling circuit 8 impresses a voltage on the thermal head 6 and operates the pulse-generating circuit 13, based on data inputted through an interface device 9 for data input. The circuit 13 generates a pulse with a pulse width based on the time constant thereof, namely, a pulse with a period varied by varying a variable resistance element 13f provided as the variable means. The outputs from the circuit 13 are inputted into the controlling circuit 8, are counted by a counting means 8a, and on completion of counting a preset number N of the pulses inputted, the power source controlling means 8b operates to stop the impressing of the voltage on the thermal head 6. |
