Fujitsu Corporation

Nobuo Kuwabara

Sachio Sasaki

Akira Nagahara

Yoshio Yamaguchi

Takefumi Takahashi

Haruyasu Watanabe

Mitsuru Sato

Tetsuya Takei

Shigenobu Utaka

Mitsuhito Furukawa

Kiyoshi Taninaka

Hiroyuki Kawai

Morihisa Kawahara

Junji Wakihara

Toshio Tooda

Hiroshi Kera

Michio Shimura

Yoshiki Nagasaki

Minoru Takano

Kunihiro Kitsu

Kunihiko Sato

Yoshiya Matsumoto

Shigeo Nonoyama

Tomohiro Hikita

Hisashi Hanzawa

Yoshiya Ishiyama

Masanori Nishido

Hisao Shishido

Mituru Sato

Image forming unit has a photosensitive drum unit and a developing unit. The photosensitive drum unit has drum shafts extending outward from opposite sides thereof. The developing unit has a through-hole and a drum shaft mounting groove for receiving the drum shafts, and developing unit rotary shafts extending outward from opposite sides thereof. An engagement lever and a toner returning cylinder are provided in the photosensitive drum unit, and a shutter is provided in the developing unit. The toner returning cylinder and the shutter are disposed between the waste toner tank of the photosensitive drum unit and the toner returning pipe of the developing unit so that they are detachable and separable from each other. Further, a mechanism is provided for pressing the developing roller onto the photosensitive drum when the photosensitive drum unit is mounted to the developing unit or when the photosensitive roller is driven.

Means for independently changing a latent image carrier unit and a developing unit in an image forming unit

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

A developing device develops a latent image formed on a latent image holding body. The developing device includes a developing roller conveying, with rotation of the developing roller, developer adhered thereto to a developing area in which the latent image on the latent image holding body should be developed, the developer including toner and carriers, a limit member, provided so as to face the developing roller, limiting a height of a layer of the developer on the developing roller, a toner container storing the toner, a toner supply mechanism supplying the toner in the toner container to the developing roller, and a partition member forming a space between the partition member and the developing roller, the toner supplied from the toner container being moved in the space with rotation of the developing roller. The developing device further includes a developer leveling member provided on an upstream side of the space in a rotation direction of the developing roller, the developer leveling member leveling the developer, formed on the developing roller, which developer has passed through the developing area.

Developing device including developer leveling member

An electrophotographic image forming apparatus includes an electrostatic latent image carrying body, an electric charger for uniformly electrifying the carrying body, an optical exposure unit to form an electrostatic latent image on the carrying body, a developer for developing the electrostatic latent image to form a toner image on the carrying body, a transfer unit for transferring the toner image from the carrying body onto a printing sheet, a fixing unit for fixing the toner image to the printing sheet, a cleaner for cleaning to remove residual toner from the carrying body and a toner returning mechanism for returning the residual toner removed by the cleaner to the developer. The developer includes a housing in which a toner chamber is defined, a developing roller rotatably mounted in the housing, an agitator rotatably mounted in the housing so as to be positioned in the toner chamber, a partitioning member provided in the housing for defining a carrier chamber adjacent to the developing roller. The toner returning mechanism includes a toner recirculator for recirculating the residual toner removed from the carrying body to the toner chamber.

Image forming apparatus having a toner cartridge

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

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

Image-forming apparatus comprising a process unit

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.

Growing community of inventors

Kawasaki, Japan

Nobuo Kuwabara