Fujitsu Corporation

Akira Nagahara

Sachio Sasaki

Takefumi Takahashi

Mitsuru Sato

Yoshio Yamaguchi

Shigenobu Utaka

Nobuo Kuwabara

Haruyasu Watanabe

Mitsuhito Furukawa

Masao Konishi

Masahiro Wanou

Hiroshi Kera

Toshio Tooda

Kunihiko Sato

Norio Sawatari

Tsuneo Watanuki

Shin Araki

Yoshiya Ishiyama

Hideaki Iwasaki

Yasushige Nakamura

Tetsuya Takei

Yoshiya Matsumoto

Toshiaki Narusawa

Satoshi Takezawa

Kenji Fuke

Hideki Kamaji

Shigeo Nonoyama

Mikio Amaya

Hisashi Hanzawa

Masanori Nishido

Shizuo Takano

Futoshi Okabayashi

Takamasa Araki

Mituru Sato

An image forming device includes an image forming part which forms an image on a recording medium; a recording medium switchback portion which receives the recording medium on a first run, one side of which has been printed when passing the image forming part, and sends the recording medium for a second run; a recording medium path which communicates with the recording medium switchback portion so as to send the recording medium to and from the recording medium switchback portion; an inverted recording medium transfer path through which the recording medium is sent to the image forming part again with an upper surface and a lower surface of the recording medium reversed; and a recording medium transfer part which transfers the recording medium along the inverted recording medium transfer path. The image forming device is further provided with a first recording medium receiving portion which stores the recording medium one on another with a printed surface facing upwards; and a first recording medium ejection path which communicates with the recording medium receiving portion so as to send the recording medium to the first recording medium receiving portion.

Image forming device

An electrophotographic image forming apparatus including a toner circulating mechanism for recovering a residual toner scraped from a photosensitive drum to a developing device. The developing device includes a housing for defining a toner chamber, a developing roller rotatably mounted in the housing, an agitator rotatably mounted in the housing and provided in the toner chamber, and a partition member mounted to the housing to define a carrier chamber between the partition member and the developing roller. The toner circulating mechanism directly returns the residual toner scraped from the photosensitive drum to the toner chamber in the developing device. The toner chamber may contain a foreign matter removing device. The partition member may have various shapes.

Electrophotographic image forming apparatus having a device for

An electrophotographic image forming apparatus includes an electrostatic latent image carrying body, an electrifying unit for electrifying the image carrying body, a light irradiating unit to form an electrostatic latent image in accordance to image information, a developing unit for discharging toner to the image carrying body to develop the latent image, a transfer unit for transferring the toner image to a recording sheet, and a cleaner for removing residual toner on the image carrying body. The toner removed from the image carrying body is recirculated to the developer receiving box. An additional toner image is formed on a position other than a first position where the electrostatic latent image is formed in accordance with the image information. The toner is removed by the cleaner without being transferred to the recording sheet and recirculated from the image carrying body to the developer receiving box.

Electrophotographic image-forming apparatus with uniform toner usage

A developing apparatus is provided for developing an electrostatic latent image on a latent image carrier by supplying the latent image carrier with a developer. This developing apparatus includes a toner accommodating chamber for accommodating magnetic toners. The apparatus also includes a developing roller, having a plurality of fixed magnetic pole members and sleeves provided along peripheries of the fixed magnetic pole members and rotating thereabout, for feeding the developer composed of magnetic carriers and magnetic toners to the latent image carrier. The apparatus further includes a developing chamber having a partition wall formed along the developing roller and assuming a configuration adapted to a shape of the developing roller, and a toner supply port for supplying the magnetic toners to the developing chamber from the toner accommodating chamber. In another mode of the developing apparatus, the center of each magnetic pole of the fixed magnetic pole members is located in a position deviating from the toner supply port. Further, in still another mode of the developing apparatus, there is employed the magnetic carrier the core of which is iron powder exhibiting strong saturation magnetization.

Developing unit having improved toner density control

An image forming apparatus which collects residual toners on a latent image carrier in a developing unit. The image forming apparatus have a rotary endless latent image carrier; an image forming unit for forming an electrostatic latent image on the latent image carrier; a developing unit for developing the electrostatic latent image on the latent image carrier with a powdery developer and collecting residual toners on the latent image carrier at a same time; a transfer unit for transferring the developed image on the latent image carrier onto a sheet; a distribution member for distributing residual toners on the latent image carrier when in contact with the latent image carrier after image transfer; and a voltage supplying unit for supplying an AC voltage to the distribution member. An image forming apparatus according to another aspect have a rotary endless latent image carrier; an image forming unit for forming an electrostatic latent image on the latent image carrier; a developing unit for developing the electrostatic latent image on the latent image carrier with a powdery developer and collecting residual toners on the latent image carrier at a same time; a transfer unit for transferring the developed image on the latent image carrier onto a sheet; and a distribution roller for distributing residual toners on the latent image carrier when in contact with the latent image carrier after image transfer.

Image forming apparatus for collecting residual toner from a drum using

An image forming apparatus for forming an image on a sheet, including a rotary endless latent image carrier, an image forming device for forming an electrostatic latent image on a latent image carrier, a developing device for developing the electrostatic latent image on the latent image carrier with powdery developers and collecting residual toners on the latent image carrier at the same time, a transfer device for transferring a developed image on the latent image carrier onto a sheet, a distribution roller having independent foam perforations for distributing residual toners on the latent image carrier when in contact with the latent image carrier after image transfer, and a power supply for supplying an AC voltage to the distribution member. The distribution member is made of a conductive foam member having a pore at a surface contacting with the latent image carrier and the roller rotates in a direction opposite to a rotational direction of the latent image carrier at a peripheral velocity of 1.1 to 1.5 times that of the latent image carrier.

An imaging device for use in an electrographic imaging process, without a cleaning unit for residual toners, which comprises an image-carrying element, an image exposure means, a developing means, an image transfer means, and a distribution roller means of an elastic and electrically conductive material for uniformly distributing the residual toners over a surface of the image-carrying element and at the same time deelectrifying and recharging the same surface of said element. The imaging device has a simplified and compact structure and does not cause an environmental pollution problem due to the generation of ozone in the device.

Cleanerless electrographic imaging device

Disclosed is an image forming apparatus capable of performing an image forming operation in both a horizontal position and an upright position. This image forming apparatus comprises a rotary endless latent image carrier; image forming unit for forming an electrostatic latent image on the latent image carrier; developing unit for developing the electrostatic latent image on the latent image carrier with a powdery developer, the developing unit having a developing room, developing rollers provided in the developing room for supplying the powdery developer to the latent image carrier, a toner supply room for supplying toners, toner supply roller provided in the toner supply room and rotatable to supply the toners to the developing room, and a partition member for partitioning the developing room and the toner supply room and forming a toner supply passage for supplying the toners to the developing room; and transfer unit for transferring the developed image on the latent image carrier to a sheet.

Image forming apparatus having a developing apparatus which includes a

Disclosed are an image forming method that removes adhered material from a latent image carrier and then forms an image on the latent image carrier, and an image forming apparatus that employs this method. The image forming apparatus includes: a developing unit for developing the latent image on the image carrier by toner and for collecting residual toner on the carrier; a transfer unit for transferring to the developed image a sheet; a removing mechanism for removing material that adheres to the carrier; a drive mechanism for rotating the carrier; and a controller for selectively executing an image forming mode, to control the individual constituent units, and an adhered material removal mode, to permit the removing mechanism to remove the material that adheres to the carrier as it is rotated by the drive mechanism. The image forming method includes: a rotation start step, for initiating rotation of an endless latent image carrier; an adhered material removal step, for permitting an removing mechanism to remove material that adheres to the carrier during at least one rotation of the carrier following the initiation of the rotation; a charging step, for applying an electrical charge to the carrier; a latent image forming step, for forming a latent image on the carrier; a developing step, for developing the latent image on the carrier and for collecting residual toner from the carrier; and a transfer step, for transferring to a sheet a toner image on the carrier.

Image forming method and image forming apparatus

An electrostatic latent image is developed on a latent image carrier and residual toners are collected at the same time. An electrostatic latent image is formed on a rotary endless latent image carrier; developer, including magnetic toners and magnetic carriers, is supplied to a developing area for developing the latent image carrier, and a magnetic brush is formed with the developer in the developing area to thereby collect residual toners on the latent image carrier and develop the electrostatic latent image on the latent image carrier; and the developed image on the latent image carrier is transferred to a sheet. An electrostatic latent image may be developed with a rotary endless latent image carrier; an image forming unit for forming an electrostatic latent image on the latent image carrier; a developing unit having a developer, including magnetic toners and magnetic carriers, and a developer supplying unit for supplying the developer to a developing area for developing the latent image carrier and forming a magnetic brush with the developer in the developing area in order to develop the electrostatic latent image on the latent image carrier with a powdery developer and collect residual toners on the latent image carrier; and a transfer unit for transferring the developed image on the latent image carrier to a sheet.

Image forming method and apparatus with magnetic brush

Disclosed is an image forming apparatus capable of performing an image forming operation in both a horizontal position and an upright position. This image forming apparatus comprises a rotary endless latent image carrier; image forming unit for forming an electrostatic latent image on the latent image carrier; developing unit for developing the electrostatic latent image on the latent image carrier with a powdery developer, the developing unit having a developing room, a developing roller provided in the developing room for supplying the powdery developer to the latent image carrier, a toner supply room for supplying toners, toner supply roller provided in the toner supply room and rotatable to supply the toners to the developing room, and a partition member for partitioning the developing room and the toner supply room and forming a toner supply passage for supplying the toners to the developing room; and transfer unit for transferring the developed image on the latent image carrier to a sheet.

Image forming apparatus

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.

Magnetic brush developing apparatus

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. A width or angle of a region where a radial component of the magnetic flux density exceeds over a half of a maximum value thereof, i.e., a half value width, is determined in such a manner that the developer is prevented from flying away from the magnetic brush.

Growing community of inventors

Kawasaki, Japan

Akira Nagahara