| 摘要 |
PURPOSE:To enable to record with stable density even when using a commercial power source accompanied by fluctuations in voltage, by passing electric currents to a plurality of heating resistor elements until electric energy reaches a reference level set for each average resistance of the resistor elements. CONSTITUTION:The voltage of the commercial power source is lowered to a predetermined value by a transformer 21, the resultant source current is rectified by diodes 22 to be a pulsating current TV, which is further smoothed by a capacitor 23, and the resultant voltage is impressed on the heating resistor elements 24 and a voltage-power converting circuit 29 as a recording voltage RV. The average resistance R of the resistor elements is inputted as a signal SEL into a reference level setting circuit 32 through a terminal 36. The circuit 32 calculates a reference level LEV, which is outputted to a level-detecting circuit 31. When it is detected by the circuit 31 that the electric energy INT has reached the reference level LEV, an RS flip-flop 28 is reset, recording pulses PLS are turned OFF, and the supply of electric currents to the resistor elements 24 is stopped. |
