| 摘要 |
PURPOSE:To reduce the contamination of a corona discharge electrode caused by a floating toner, by impressing an AC voltage to which a voltage or a DC component of the polarity opposite to a developer floating in the periphery of a carrying body is superposed, to an air flow control member installed at the upstream side of a shield member of a corona discharge device of an electronic copying device. CONSTITUTION:A corona discharge device is provided with a photosensitive body 5 being an image carrying body, a shield member 16, a discharge wire 15 being a corona discharge electrode, an insulating member 17, an air flow control member 18 having a conductivity, and external power sources 19, 20. By applying an AC voltage to which a voltage or a DC component of the polarity opposite to a developer floating in the periphery of an image carrying body is superposed, to the air flow control member 18, a toner particle carried by an air flow of the upper layer goes in the direction as indicated with an arrow (a), and does not go into the shield member 16. As for the floating toner particle entered between the photosensitive body 5 and the air flow control member 18, the toner particle is pressed against the photosensitive body 5 by applying a voltage to the air flow control member 18 from the power source 19, or collected to the air flow control member 18. |
