Canon Kabushiki Kaisha

Syuhei Kawasaki

Seiichi Shinohara

Seiji Yamaguchi

Hiroshi Sato

Tachio Kawai

Kojiro Yasui

Hironobu Isobe

Yasufumi Yoshino

Hiroaki Ogata

Issei Imamura

Shinji Uehara

An image forming apparatus includes an image bearing member; a developing device including a carrying member for carrying a one component developer and for developing an electrostatic image formed on the image bearing member with the developer; a rotatable developer supplying device, contacted to the carrying member, for supplying the developer to the carrying member; a developer regulating device for regulating an amount of the developer carried on the carrying member; a developer stirring device for stirring the developer a developer supply device for supplying the developer to the developing device; and a controller for controlling supply of the developer to the developing device from the developer supply device. A lower end of the developer stirring device is disposed at a position which is vertically above an upper end of the developer supplying device and which is vertically above a contact portion between the carrying member and the developer regulating device. A direction of rotation of the developer supplying device is such that the developer supplying device is contacted to the carrying member during a downward part of the rotation of the developer supplying device. The controller controls the developer supply device such that a lower limit of a height of a surface of the developer is vertically above a lower end of the developer stirring device and an upper limit of the height of the surface of the developer is vertically below a wall of an upper surface of the developing device.

Image forming apparatus

A developing device includes a developer container divided into a developing section and a mixing section in which developer is conveyed in the opposite directions. A conveying member which conveys the developer in the longitudinal direction is disposed only in the developing section, and a mixing member which does not positively convey the developer in the longitudinal direction is disposed in the mixing section.

Developing device, process cartridge, and electrophotographic image-forming apparatus

A developing apparatus develops a latent image formed on an electrophotographic photosensitive member with a developer in an electrophotographic image forming apparatus The device includes a developer accommodating portion and a developer stirring member stirring the developer in the developer accommodating portion. The developer stirring member includes a rotatable member rotatably provided in the developer accommodating portion, first and second stirring rotatable portions provided on the rotatable member, and first and second movable stirring portions movably provided on the first and second stirring rotatable portions, respectively. The radius of rotation of the first and second stirring rotatable portions are different from each other, and a part of a stirring region in which the first stirring rotatable portion and the first movable stirring portion stir the developer and a part of a stirring region in which the second stirring rotatable portion and the second movable stirring portion stirs the developer, overlap.

Developing apparatus

An image forming apparatus includes an image bearing member; a plurality of developing devices for developing electrostatic images formed on the image bearing member with developers, the developing devices including respective developer carrying members for carrying respective developers; moving means for moving a selected one of the developing devices to an operative position, wherein each of the developer carrying members is movable selectively to be in contact with or spaced from the image bearing member at the operative position; wherein the apparatus is operable in a first image formation mode in which an image is formed using the plurality of developing devices and a second image formation mode in which an image is formed using one of the plurality of developing devices, and wherein the developer carrying member which is at the operative position in the first image formation mode is capable of being spaced from the image bearing member by a first distance during non-developing-operation, and the developer carrying member which is at the operative position in the second image formation mode is capable of being spaced from the image bearing member by a second distance during non-developing-operation, and wherein the second distance is smaller than the first distance.

A developing cartridge is detachably mountable to a main assembly of an electrophotographic image forming apparatus. The cartridge includes a developing roller, for developing an electrostatic latent image formed on an electrophotographic photosensitive member, having an elastic roller portion and a shaft portion supporting the elastic roller portion, a developer regulating member; a protecting member including a contact portion provided for contact with the elastic roller portion when the protecting member is demountably mounted between the developing roller and the developer regulating member; and a supporting portion for supporting the contact portion and provided for contact with the elastic roller portion when the protecting member is demountably mounted between the developing roller and the developer regulating member. The contact portion has a hardness which is not less than a predetermined value and not more than a hardness of the elastic roller portion.

Process cartridge, developing cartridge and developing roller

An image forming apparatus includes an image bearing member; a plurality of developing devices for developing electrostatic images formed on the image bearing member with developers, the developing devices including respective developer carrying members for carrying respective developers; moving devices for moving a selected one of the developing devices to an operative position, wherein each of the developer carrying members is movable selectively to be in contact with or spaced from the image bearing member at the operative position. The apparatus is operable in a first image formation mode in which an image is formed using the plurality of developing devices and a second image formation mode in which an image is formed using one of the plurality of developing devices. The developer carrying member which is at the operative position in the first image formation mode is capable of being spaced from the image bearing member by a first distance during non-developing-operation. The developer carrying member which is at the operative position in the second image formation mode is capable of being spaced from the image bearing member by a second distance during non-developing-operation, wherein the second distance is smaller than the first distance.

Growing community of inventors

Susono, Japan

Syuhei Kawasaki