Fujitsu Corporation

Takamasa Araki

Kunihiko Sato

Sachio Sasaki

Akira Nagahara

Kenji Fuke

Shin Araki

Jun Shimizu

Hideaki Iwasaki

Futoshi Okabayashi

Kazuyoshi Sakazawa

A developer stirring device including stirring paths parallel to each other and stirring screws respectively disposed in the stirring paths, in which a delivering element for a developer is provided on one of the stirring screws and a distributing element is provided on the other of the stirring screws so as to allow the developer to circulate through the stirring paths without stagnation, and a developing device for an image forming apparatus using the same.

Developer stirring device and developing device and image forming

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

Growing community of inventors

Hyogo, Japan

Takamasa Araki