Minolta Camera Kabushiki Kaisha

Minolta Company, Ltd.

Susumu Mikawa

Tamotsu Shimizu

Masahiko Matsuura

Hiroshi Murasaki

Noboru Ito

A developer mixing and transporting member is provided which has at least two independent spiral-shaped channels extending around the circumference of the member. At least one of the channels is partly blocked by an element which restricts developer transport through the channel so that developer being mixed and transported within each of the channels is transported at different speeds and is thus rapidly mixed.

Developing device having a member for restricting transport of developer

A developing device which develops an electrostatic latent image formed on an image-bearing member in an image forming apparatus. The developing device has a developer transporting member for transporting a developer to the image-bearing member, and a rotatable regulating member provided at an upstream side from the developing region with respect to a transporting direction of the developer transporting member for regulating an amount of the developer held on the developer transporting member. The regulating member includes a regulating portion which has a section wherein a distance from a rotational axis of the regulating member to periphery of the regulating portion is not fixed.

Image forming apparatus with member for regulating an amount of

In an image forming apparatus accommodating a developing device, a developing roller 1 includes a magnet member 3 non-rotatably fixed and a sleeve 2 rotatably moved around the outer surface of the magnet member 3, powdery developers D held on the outer periphery of the sleeve 2 are brought into contact with a photosensitive member 10 to visualize an electrostatic latent image, and the magnet member 3 is provided with a magnetic pole portion N.sub.0 having first and second magnetic poles N.sub.1 and N.sub.2. The first and second magnetic poles N.sub.1 and N.sub.2 have the same polarities and are adjacent to each other and confront the photosensitive member 10. The powdery developers D include three developer parts, an upper developer D.sub.1, a middle developer D.sub.12 and a lower developer D.sub.2, which are successively retained on the outer surface of the sleeve 2 by the first and second magnetic poles N.sub.1 and N.sub.2. The upper developer D.sub.1 retained by the first magnetic pole N.sub.1 and the middle developer D.sub.12 retained by the middle portion between the first and second magnetic poles N.sub.1 and N.sub.2 are brought into contact with the photosensitive member, while the lower developer D.sub.2 retained by the second magnetic pole N.sub.2 is held out of contact with the photosensitive member.

Developing device for use in an image forming apparatus

A developing device comprises a rotatable developing sleeve, a magnet member stationarily disposed inside the developing sleeve and a developer restricting member which restricts an amount of developer transported on a peripheral surface of the developing sleeve toward a developing region in accordance with rotation of the developing sleeve. The magnet member has a developing magnetic pole confronting the developing region, an identical polarity magnetic part which is provided between the developer restricting member and the developing magnetic pole and is formed of a plurality of adjacent magnetic poles of an identical polarity, and a magnetic pole which is provided between the identical polarity magnetic part and the developing magnetic pole for transporting the developer.

Growing community of inventors

Itami, Japan

Susumu Mikawa