Fujitsu Corporation

Kenji Fuke

Yoshihiro Tonomoto

Katsumi Sugimoto

Katsuya Shimatsu

Eiji Suzuki

Tomoaki Tanaka

Keiko Tonai

Yasuhiro Wakabayashi

Kunihiko Sato

Hitoshi Yoshii

Hiroaki Yoshida

Tsutomu Kawai

Shozo Tonai

Sachio Sasaki

Kiyoshi Chinzei

Tsuneo Mizuno

Akira Nagahara

Naoto Hirao

Hideyuki Nanba

Shin Araki

Masaaki Ohyama

Shigenobu Utaka

Kiyoshi Nakamichi

Teturou Nakashima

Daisuke Fujii

Katsumi Tateno

Hideaki Iwasaki

Kazumi Kawabata

Futoshi Okabayashi

Takamasa Araki

Yoshimi Takizawa

Yoshito Hukata

A printer including a photosensitive drum on which a toner image is formed, a plurality of transfer wires held in facing relation to the drum, and a static-eliminating wire located downstream from the transfer wires. Transfer currents are conducted through a selected one or more of the transfer wires in accordance with the thickness of recording paper used in the printer.

Printer and transfer charger

A developing apparatus develops a latent image formed on a latent image carrying body with a developer. The developing apparatus includes a developing unit having a means for supplying the developer to the latent image carrying body to develop the latent image on the latent image carrying body and a developer housing for accommodating the developer. A developer storage box stores the developer which is to be supplied to the developing unit. The developer storage box is detachably mounted on the developing unit and has a volume substantially the same as a volume of the developer which can be accommodated in the developer case of the developing unit. The developer in developer storage box is supplied to the developing unit.

Image forming apparatus utilizing a two-component developing apparatus with automatic toner replenishment and developer replacement

An automatic cleaning method for cleaning an electrifier of an image forming apparatus. A drive mechanism moves the cleaning member to clean the electrifier. An electrification time measuring section measures an electrification time of the electrifier after the last cleaning of the electrifier. A medium detecting section discriminates whether or not a medium is located in an image forming station. A control section controls the drive mechanism to render the cleaning member to clean the electrifier when a medium is not present in the image forming station after the measured electrification time reaches a determined time. The result is that automatic electrifier cleaning can be done at an appropriate preset timing, causing an elongated service life of the electrifier.

Automatic cleaning method for electrifier, and image forming apparatus

The invention provides a double-sided printing apparatus which includes a first image forming process unit, a second image forming process unit, a first fixing station, a second fixing station and a transport system all disposed in a first housing. The transport system includes a transport direction changing element which contacts with one of surfaces of a medium to change the transporting direction of the medium so that the medium is sent out to the second fixing station. While the medium is transported in a substantially vertical direction in the single double-sided printing apparatus, the height of the transport path of the medium is suppressed so as not to become very high, thereby miniaturizing the apparatus. Further, intense light leaking from the fixing stations is intercepted so that deterioration of photosensitive drums of the image forming process units is prevented and a drop of the surface potentials of the photosensitive drums is prevented to extend the life of each photosensitive drum and prevent deterioration of the printing quality.

Double-sided printing apparatus

A fixing unit is provided with a fixing heat roller, a first reel supplying a cleaning member which cleans a surface of the fixing heat roller, a second reel taking up the cleaning member from the first reel, and a unidirectional clutch mechanism intermittently driving the second reel in a direction to take up the cleaning member using rotation of the fixing heat roller.

Fixing unit with undirectional clutch mechanism and image forming

A developing device for developing an electrostatic latent image with a two-component developer comprises a developer container (46) including a developer-accumulating chamber (50), and a developer-agitating chamber (56) provided above the developer-accumulating chamber. A communication passage (64) is provided between the developer-agitating chamber and the developer-accumulating chamber, and is opened to the developer-agitating chamber to define an overflow opening for the developer. The device also comprises a developer-carrying body (48) provided in the developer-accumulating chamber of the developer container, and the developer-carrying body is exposed to face an electrostatic latent image carrying body, and brings the developer from the developer-accumulating chamber to a facing zone therebetween for development of an electrostatic latent image formed on the electrostatic latent image carrying body. The device further comprises a developer-lifting means (68, 68', 70) for lifting the developer, brought to the facing zone by the developer-carrying body, to the developer-agitating chamber of the developer container, and a developer-agitating means (58) for agitating the developer in the developer-agitating chamber of the developer container, a part of the developer agitated by the developer-agitating means being fed to the developer-accumulating chamber through the overflow opening and the communication passage.

Developing device for electrostatic latent image

An image forming apparatus including a plurality of developing units each having a developer storage portion for accommodating a developer; a plurality of feeding devices for discharging used developers from the respective developing units; and a single collecting device for collecting the used developers discharged by the respective feeding device.

Toner recovery device

An electrostatic recording system using a dielectric belt for conducting electrification of a sheet of paper and a transfer belt so that the sheet of paper is not wound and caught by a photoconductor drum, and a transfer voltage can be lowered so as to smoothly separate the sheet of paper from a transfer belt. The electrostatic recording system applies a voltage to only the dielectric belt at a stage before the sheet of paper 3 is attracted to the dielectric belt 10 and applies voltage to the sheet of paper 3 conveyed to the dielectric belt, and to the dielectric belt 10 while the sheet of paper and the belt are mutually superposed.

Electrostatic recording system using dielectric belt in which

To provide a photo-sensitive drum having excellent properties which are not at all inferior to those of the prior art photo-sensitive drums assembled with a larger number of parts, capable of being easily manufactured at a reduced production cost. A blank tube 23d consisting of a cylinder section 23a, a center axis section 23b arranged within the cylinder section 23a concentrically therewith and a plurality of rib sections 23c for rigidly connecting the cylinder section 23a with the center axis section 23b is integrally formed through extrusion or draw-forming.

Photo-sensitive drum formed from extruded or drawn blank and image

Multicolor electrostatic recording apparatus and electrostatic latent

A toner image transferring device is used to electrostatically transfer a charged toner image from a roller to a sheet of paper. The device includes a transfer charger for giving the paper an electric charge. A charge eliminator is located next to the roller for partially eliminating the electric charge from the paper. The charge eliminator is positioned to be adjacent to the paper and the roller, but displaced from the transfer charger. Paper passes through the device such that the paper is in contact with the roller when passing over the transfer charger, thereby optimizing the transfer of the toner image from the roller to the paper.

Toner image transferring device including transfer charger and AC charge

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.

Magnetic brush developing apparatus

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Kawasaki, Japan

Kenji Fuke