Mita Industrial Co., Ltd.

Hitoshi Nishihama

Tatsuo Aizawa

Nobuhiko Kozuka

Shoji Matsumoto

Shigeo Koyama

Toshikazu Matsui

Toshimitsu Ikeda

Ryutaro Yamagata

Minoru Motomura

Katsuhiko Gotoda

Kazutada Sakai

Takanobu Nakajima

Eiichi Inoue

Yasushi Kamezaki

Akira Fushida

Tadanobu Nakajima

Joji Matsumoto

A method for transferring a toner image on the surface of an image-bearing member obtained as a result of development with a conductive or semi-conductive toner material to the surface of a receptor member, which comprises bringing the surface of the receptor member into contact with the toner image on the surface of the image-bearing member and simultaneously applying a corona discharge to the back surface of the receptor member. The angle formed between the lines of electric force of the corona discharge and a line perpendicular to the receptor member does not exceed about 30 degrees.

Method for transferring toner image

An electrostatic copying machine apparatus includes a developing device having a fixedly positioned permanent magnet and a hollow developing sleeve formed of a non-magnetic material mounted coaxially about the permanent magnet for rotation thereabout. Toner supplied to the periphery of the sleeve forms thereon a magnetic brush which is conveyed by rotation of the sleeve to a developing position whereat the toner is transferred to a photoreceptor as a visible toner image. A bristle cutting member is positioned upstream of the developing position to restrict the length of the magnetic brush. A blade member formed of a non-magnetizable material prevents solidification of the toner on the periphery of the sleeve and is positioned upstream of the bristle cutting member. The blade member slides in contact with the periphery of the sleeve at a scraping position. The permanent magnet has spaced therearound at equal circumferential intervals a plurality of magnetizing positions having magnetic poles. One pole is at a first magnetizing position confronting the bristle cutting member, and another pole is at a second magnetizing position confronting the scraping positions. These two poles are of opposite polarities and are adjacent to each other. At least one magnetizing position includes a pair of poles of the same polarity.

Developing device for use on an electrostatic copying apparatus

A cleaning device for use on a transfer type electrostatic copying apparatus includes a magnetic brush cleaning device for cleaning off a magnetizable toner remaining on a photosensitive material after a transfer operation. A brush roller is disposed between the magnetic brush cleaning device and a transfer zone. A brush is arranged on a peripheral surface of a cylindrical sleeve of light transmitting material and is driven for rotation in contact with the photosensitive material. A charge eraser lamp is secured within the cylindrical sleeve. The charge on the photosensitive material or photoreceptor is almost completely erased, and consequently, the cleaning efficiency is markedly improved owing to the facilitated removal of the developing material by the magnetic brush.

Cleaning device for use on an electrostatic copying apparatus

An apparatus for developing a latent electrostatic image, includes a developer holding member having a surface adapted for movement through an endless path and a developer receptacle having an opening formed at a site opposite to a part of the endless path. The receptacle contains a one-component developer consisting only of toner particles capable of retaining an electric charge. The developer in the receptacle is held on the surface of the developer holding member and charged by a charging member. The charged developer is carried to a developing zone by the movement of the surface of the developer holding member and applied to a latent electrostatic image to be developed.

Apparatus for developing latent electrostatic image

In an electrostatic photographic process comprising subjecting an electrostatic photographic photosensitive plate to the combination of negative charging, positive charging and imagewise exposure to form an electrostatic latent image of a positive polarity, said electrostatic photographic photosensitive plate having such charging characteristics that a photosensitive layer can be positively charged by sequential negative corona charging and positive corona charging and positive charging is rendered substantially impossible by irradiation with light, and then subjecting the so treated photosensitive plate to positive charging a predetermined number of times, whereby an electrostatic latent image is formed the predetermined number of times by imagewise exposure conducted once, if a zinc oxide-resin dispersion is used for the photosensitive layer of the photosensitive plate and predetermined amounts of a triphenylmethane basic dye and a silicone oil are incorporated in the photosensitive layer, the time required for negative charging can be shortened, and the charge potential at the time of positive charging can be increased and accumulation of the residual potential after irradiation with light can be reduced.

Multiple copy electrophotographic process using dye sensitized ZnO

An electrophotograhic copying process forms an electrostatic latent image on the surface of a photosensitive member, developes the image by applying a monocomponent developer to the latent image to form a toner image, transfers the thus formed toner image by contacting a receptor sheet with the photosensitive member to transfer the toner image to the surface of the receptor sheet, fixes the toner image onto the surface of the receptor sheet, eliminates electrostatic charge from the photosensitive member by irradiating the surface of the photosensitive member with an electrostatic eliminating lamp after the toner image has been transferred to the receptor sheet, and cleans the surface of the photosensitive member by removing the developer remaining on the surface thereof. A developer-holding member holds the same kind of developer as used in the developing step on the surface of said developer-holding member by a stationary magnet disposed within the developer-holding member, and the surface of the developer-holding member is moved in a direction opposite to the direction of movement of the surface of the photosensitive member while contacting the two surfaces through the layer of the developer to mechanically brush the surface of the photosensitive member by the layer of the developer. The magnet having a plurality of poles, and the magnetic pole which is located closest to a position at which the surface of the developer-holding member is closest to the surface of the photosensitive member is downstream in the rotation direction of the developer-holding member by a certain angle with respect to the position at which the two surfaces are closest to each other.

Cleaning process for an electrostatic copying apparatus

An electrostatic copying apparatus has a housing having at its top surface a transparent plate on which to place an original to be copied, a rotary drum disposed within the housing and having a photosensitive member on its surface, a charging, a developing, a transferring and a cleaning mechanism which are successively arranged around the rotary drum in the moving direction of its surface, an optical system for projecting the image of the original onto the surface of the rotary drum between the charging mechanism and the developing mechanism, and a receptor sheet conveying system for transporting a receptor sheet through a transfer station defined between the surface of the rotary drum and the transferring mechanism. A support is mounted on the housing so that it is slidable in the forward and rearward directions between its operating position within the housing and its pulled-out position ahead of the housing, and the rotary drum and the developing device are mounted on the support so that they can be separately and independently detached from the support. An electrostatic copying process can be efficiently practiced by using this apparatus.

Electrostatic copying process and apparatus

An electrostatic copying apparatus has a housing having at its top surface a transparent plate on which to place an original to be copied, a rotary drum disposed within the housing and having a photosensitive member on its surface, a charging, a developing, a transferring and a cleaning mechanism which are successively arranged around the rotary drum in the moving direction of its surface, an optical system for projecting the image of the original onto the surface of the rotary drum between the charging means and the developing means, and a receptor sheet conveying system for transferring a receptor sheet through a transfer station defined between the surface of the rotary drum and the transferring mechanism: A support is mounted on the housing so that it is slidable in the forward and rearward directions between its operating position within the housing and its pulled-out position ahead of the housing, and the rotary drum and the developing device are mounted on the support so that they can be separately and independently detached from the support. An electrostatic copying process can be efficiently practiced by using this apparatus.

Electrostatic copying process

A transfer sheet on which toner images free of broadening of edge portions and having sharp contours can be transferred even in the electrophotography or electrostatic printing of the transfer type using conductive or semiconductive toners, i.e., magnetic toners, is disclosed. This transfer sheet is characterized in that a conductive or semiconductive toner-receiving face having a volume specific resistance of at least 3.times.10.sup.13 .OMEGA.-cm is formed on at least one surface of a substrate of the transfer sheet.

Electrophotographic process, of transferring a magnetic toner to a copy

An apparatus for developing an electrostatic latent image formed on the surface of an electrostatic latent image-bearing material by applying a powdery developer, wherein means are provided for bringing the surface of a developer-retaining member retaining a layer of the powdery developer thereon into rolling contact with the surface of the image-bearing material in such a relation that a reservoir zone of the developer is formed at least upstream of the zone of rolling contact between the two surfaces, and means are provided for physically disturbing the developer in the reservoir zone to cause the developer to make an irregular motion.

Apparatus for causing a developer powder to make an irregular motion in

Method and apparatus for developing an electrostatic latent image formed on the surface of an electrostatic latent image-bearing material by applying a powdery developer, wherein the surface of a developer-retaining member retaining a layer of the powdery developer thereon is brought into rolling contact with the surface of the image-bearing material in such a relation that a reservoir zone of the developer is formed at least upstream of the zone of rolling contact between the two surfaces, and the developer in the reservoir zone is physically disturbed.

Method for developing electrostatic latent images

An electrophotographic process comprising forming an electrostatic image on the surface of a sensitive member, transferring the electrostatic image onto the surface of a transfer member, and developing the image so transferred. The process specifically involves using an overcoated sensitive member consisting essentially of an electrically conductive base, a photoconductive layer and a light-transmitting surface insulating layer, subjecting the sensitive member to a primary charging in a specific polarity using a direct current corona discharge, exposing light and dark images on the surface of the sensitive member and simultaneously subjecting it to a secondary charging until the surface of the sensitive member has the same polarity as in the primary charging and its potential becomes substantially equal to the untransferable upper limit potential, exposing the entire surface of the sensitive member to render the potential of the dark image area higher than the untransferable upper limit potential without substantially changing the potential of the light image area, transferring the electrostatic image so formed on the surface of the sensitive member to the surface of a transfer member, and then developing the electrostatic image so transferred thereby to form visible images.

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Hirakata, Japan

Hitoshi Nishihama