| 摘要 |
PURPOSE:To eliminate residual voltage to protect against electroerosion and thereby improve reliability by providing a control circuit for controlling to interrupt the supply of voltage for recording action except during recording action and a rapid discharging circuit for causing the voltage for recording action to drop rapidly at the time of shutting off the voltage. CONSTITUTION:Voltages (-)250V and (+)3,000V are applied to drive circuits 12, 13 from a power supply circuit 11. Then recording pulses 2P, 3P are supplied almost simultaneously to a needle electrode 2 and a control electrode 3 under the control of a control circuit 14 during recording action. Consequently, an electrostatic latent image corresponding to a recording image is formed on recording paper. When this recording action ends, the control circuit 14 issues a command, while the power supply circuit 11 stops a voltage for recording action immediately. In addition, a voltage for recording action is caused to drop to almost zero prior to the stopping of transport of the recording paper, by selecting the resistance value of resistor 15a for rapid discharging circuits 15, 16 below a predetermined value. This results in the elimination of residual voltage which accelerates electroerosion of an electrode. |
