Abstract: A magnetic brush developing apparatus includes a development container containing a developer. A magnet is stationarily located in the development container and has magnetic poles radially provided on a plurality of points. A rotational sleeve is arranged to cover the outer circumference of the magnet and is rotatably driven to carry the developer in the development container. A blade is arranged opposite to the rotational sleeve to restrict the amount of the developer which is carried by the rotational sleeve. To obtain a uniform image quality without unevenness among different developing apparatus and a wider range of assembling precision to thus facilitate the installment of the apparatus, at a position facing the developer restriction member, and in its vicinity, there is formed a uniform magnetic flux density section having a magnetic flux density whose vertical component is substantially uniform on the periphery of the rotational sleeve.

Abstract: A magnetic brush developing apparatus, comprising: a development container (102) for containing a developer; a magnet (122) stationarily located in the development container and having magnetic poles radially provided on a plurality of points; a rotational sleeve (121) arranged to cover the outer circumference of the magnet and rotatably driven to carry the developer in the development container to an image carrying body (131); and a blade (123) arranged opposite to the sleeve to restrict the amount of the developer which is carried by the sleeve. Two of the magnetic poles are a developing magnetic pole (Pd) facing opposite to the image carrying body (131) and a developer transfer magnetic pole (Pt) located between the developing magnetic pole (Pd) and the blade (123). A magnetic brush of the developer formed on the sleeve (121) by the developer carrying magnetic pole (Pt) has a magnetic flux density.

Abstract: A toner image transferring device is applied to, for example, an electrophotographic printer for electrostatically transferring a charged toner image from a photosensitive drum to a sheet or paper. The device encompasses a transfer charger disposed near the drum to form a clearance therebetween for feeding an electric charge to the sheet or paper through which the sheet or paper is passed, an electric source for supplying an electric energy to the transfer charger to give the sheet or paper an electric charge having a polarity opposite to that of the charge of the toner image, and a controller for controlling the electric energy output from the electric source the transfer charger so that a leading edge of the sheet or paper can be prevented from being excessively charged.

Abstract: A compact and simple structured electrophotographic printing apparatus having a single magnetic developer, in which an accumulation of toner particles is formed on a photosensitive member at a downstream position from the magnetic developer. The accumulation of the toner particles is formed by moving a photosensitive film and a magnetic brush in rubbing contact with the film in mutually opposite directions, or by deforming a magnetic field generated by the magnetic developer, using a magnetic piece. A recording electrode is disposed on a sleeve of the magnetic developer and facing the photosensitive film. Bias voltages, having polarities opposite to each other with respect to the photosensitive film, are respectively applied to the recording electrode and the sleeve. An optical beam is projected onto the photosensitive film in a region facing the recording electrode.