| 摘要 |
PURPOSE:To perform good transfer without requiring the power source of a transfer roll even when the absolute value of drum potential is largely taken, by applying an electric field attracting an ion to the surface of a recording body and setting the transfer roll to ground potential. CONSTITUTION:The surface of a recording drum 1 is pre-charged to -1600V by a pre-charge crotron 3 to which the voltage from a negative power source 2 is applied. Reversal development is performed by a developing device 5 irradiating the image forming position on the surface of the drum 1 with a positive ion by a grounded ion current control head 4 to allow the potential of the drum 1 to approach 0V to adhere toner to the part irradiated with the positive ion. The potential of the toner image subjected to reversal development becomes -1500V. The transfer roll 6 brought into contact with the drum 1 under pressure is constituted of a conductor 6a and the dielectric body 6b covering said conductor and the inside conductor 6a is grounded. A grounded conductive roll 7 is brought into contact with the roll 6 under pressure and the toner on the drum 1 is transferred to recording paper 8 on the basis of the difference between the potential of the transfer roll 6 releasing the surface charge of the drum 1 and the potential of about -1500V of the toner image. |
