| 摘要 |
PURPOSE:To improve the stability and reliability of a recording unit by such an arrangement wherein an ink current is accelerated and stabilized by causing it to fly together with air current supplied from an air supply source, by this arrangement, the rise time and fall time of air pressure at the time of starting and stopping of the air supply source are made to be variable. CONSTITUTION:By closing an air control switch 26, the output of a standard power source 25 is inputted into an integration circuit 27 through the switch 26. As its output generates a certain time delay for the input, the rise and fall of the circuit become dilatory. Since such rise and fall characteristics are determined by the time constant of the integration circuit 27, for example, a variable resistor is used as a resistor, and by this, desired rise and fall characteristics can be realized by adjusting the time constant of the integration circuit 27 through the regulation of the variable resistor. A motor drive circuit 28 amplifies the output of the integration circuit 27 for driving a DC motor 24. Since the rise and fall characteristics of the DC motor can be controlled by varying the time constant of the integration circuit 27, by driving an air pump of an air supply source, the rise and fall characteristics of its pressure at the time of starting and stopping can be controlled. |
