Abstract: In a dry type developing device having a magnetic field producing means, nonmagnetic developer supporting means, means for moving said magnetic field producing means and said nonmagnetic developer supporting means relative to each other, and means for supplying developer to that side of the nonmagnetic developer supporting means which is opposite to the magnetic field producing means, the surface of the nonmagnetic developer supporting means which is adjacent to the developer supply means is provided with plating containing grains therein.

Abstract: A transfer corona current is always maintained substantially constant independently of the surface potential of a photosensitive medium and environmental conditions, to thereby prevent the amount of charge on the back side of a transfer medium from fluctuating in accordance with said surface potential and environmental conditions. In addition, a separation corona current is maintained substantially constant to thereby further improve the stability of electrostatic separation. The transfer corona current is below a critical current value whereat the corona charge passes through the transfer medium, and the separation corona imparts to the back side of the transfer medium an amount of charge substantially equal to the amount of charge provided by the transfer corona.

Abstract: A charged body is electrically discharged by the use of AC corona discharge, whereafter the AC corona discharge current is gradually attenuated before the discharging is stopped, and then the corona discharge is stopped.

Abstract: An electrophotographic apparatus includes a photosensitive member with a conductive layer, a photoconductive layer and an insulating layer; a variably controlled primary corona discharger for applying a charge of a predetermined potential onto the surface of the photosensitive member, a secondary corona discharger for applying a corona discharge containing a component of which polarity is opposite to that of the primary corona discharge; an imagewise exposure device for exposing the photosensitive member to an image light substantially simultaneously with the corona discharge by the secondary corona discharger, and high voltage source, for supplying predetermined high voltages to the primary and secondary corona discharger, having a high voltage transformer provided at least with a primary input coil, a secondary high voltage output coil and a tertially coil associated with a variable load impedance. An electrostatic latent image of a predetermined contrast is formed on the photosensitive member.

Abstract: An electrophotographic apparatus constructed with a photosensitive body, a primary charger to apply a substantially uniform primary charge to the photosensitive body, a secondary corona discharger to apply to the photoconductive body either an AC corona discharge or a corona discharge of an opposite polarity to that of the primary charge so as to form an electrostatic latent image on the photosensitive body, the secondary corona discharge application being effected substantially simultaneously with irradiation of an image to be reproduced, wherein the secondary corona discharger is provided with a device to control discharge conditions.

Abstract: This specification discloses a device for developing electrostatic latent images by the use of developer. The device includes a photosensitive medium bearing electrostatic latent images on the surface thereof to be developed, a container for containing therein magnetic carrier and toner, a permanent magnet fixedly mounted within the container, and a non-magnetic sleeve enclosing the magnet and rotatably mounted in the container for transporting the developer from the container to the latent image bearing surface. The permanent magnet has poles of identical polarity disposed adjacent to each other at positions opposed to the latent image bearing surface. Thus, development can be effected in the developing station by utilization of repelling magnetic fields produced by the poles of identical polarity.