Ricoh Company, Ltd.

Seiichi Miyagawa

Itsuo Ikeda

Shigeru Suzuki

Mitsuo Hasebe

Junji Kurokawa

Hajime Hariu

A solid state corona discharger in corona chargers which charge and discharge photosensitive members in electrophotographic copying machines, ozone generators and the like. The solid state corona discharger has paired strip-shape ac electrodes which are arranged side by side nearly in parallel and spaced away from each other not to initiate discharge, a dielectric member layer which covers at least one side of the external surfaces enveloping both electrodes, and a thin dc-applied electrode which is in contact with one side of external surface of said dielectric layer and makes up a closed circuit loop of capacitances together with said ac electrodes (not connected in terms of direct current), as well as characterized by producing corona discharge between said ac electrodes and a dc-applied electrode with an ac power supply applied across said ac electrodes. In using the solid state corona discharger according to said configuration as a charger for a thin substance to be charged, the substance is charged by placing a dc-applied electrode opposite to the surface of the substance; connecting a dc power source between the dc-applied electrode and the surface to be charged; and generating a dc electric field between the solid state corona discharger and said surface to be charged; as well as by initiating corona discharge between an ac electrode and a dc-applied electrode.

Solid state corona discharger

An electrophotographic color image forming process wherein three light beams each representing image information of one of three primary colors or yellow, magenta and cyan of a color document to be recorded obtained by color separation are projected against an electrophotographic photosensitive member to form electrostatic latent images which are developed by toners of the three different colors, respectively, and printed by transfer-printing, to record a color image. The image information of three colors is simultaneously written to a surface of the photosensitive member as three scanning lines either by successively writing a plurality of sets of three scanning lines each representing image information of one color or by writing image information of different colors of the same set separately in three different zones, so that the scanning lines representing image information of different colors form a repeating series of three stripes of different colors. The electrostatic latent images formed on the scanning lines are excited in positions immediately before developing sections of respective colors and developed by the toners of respective colors to produce toner images of different color which are printed by transfer-printing on a transfer-printing sheet.

Growing community of inventors

Nagareyama, Japan

Seiichi Miyagawa