Canon Kabushiki Kaisha

Shinya Yamamoto

Hiroaki Ogata

Hiroshi Sasame

Tetsuya Kobayashi

Kohei Matsuda

Tomomi Kakeshita

Takeshi Kawamura

Shinichi Agata

Masato Koyanagi

Yasunari Watanabe

Kazushige Sakurai

Takashi Hibi

Kentaro Kawata

Yuichiro Hirata

Kodai Hayashi

Taku Watanabe

Kentarou Kawata

Hideki Maeshima

Motoki Adachi

Yoshihiro Mitsui

Hisashi Taniguchi

Kuniaki Hirukawa

Kouji Hashimoto

Nobuyoshi Yoshida

Yuji Moriki

Soya Endo

Yasunori Toriyama

Koichiro Takashima

Yasuomi Aso

In a development device in which a developer containing unit underlies a development chamber, a supplying member in the development chamber forms a nip portion with a developer carrier and the developer carrier and the supplying member rotate in the direction in which their respective surfaces move from an upper end to a lower end of the nip portion.

Development device, process cartridge, and image forming apparatus

An electrophotographic image forming apparatus includes an electrophotographic photosensitive member configured to bear an electrostatic latent image, and a developer carrying member configured to develop the electrostatic latent image. The electrophotographic photosensitive member and the developer carrying member are separated from each other during non-image formation and brought into contact with each other after the electrophotographic photosensitive member and the developer carrying member start to be rotated. During a time period between a time when the electrophotographic photosensitive member and the developer carrying member start to be rotated and a time when the electrophotographic photosensitive member and the developer carrying member are brought into contact with each other, a number of revolutions of the developer feed member is larger than a number of revolutions of the developer carrying member.

Electrophotographic image forming apparatus

An electrophotographic image forming apparatus for forming an image on a recording material includes an electrophotographic photosensitive member (drum); a developer carrying member; a cleaning blade for cleaning the drum; a developer seal member of a peripheral surface seal type, provided at an end portion of the developer carrying member, for preventing leakage of the developer; and a developer retaining member provided at an end portion of the cleaning blade. With respect to a longitudinal direction of the drum, the developer seal member is disposed in a region where the cleaning blade is provided, an inside end position of the retaining member is located at the same position as or inside an inside end position of the developer seal member, and an outside end position of the retaining member is located at the same position as or outside an outside end position of the developer seal member.

Electrophotographic image forming apparatus and process cartridge

A developing apparatus including a developing container for containing developer, the developing container having an opening portion, a developer carrying member for carrying the developer at the opening portion, a detecting member for detecting a developer amount, the detecting member detecting a capacitance between the developer carrying member and the detecting member, and a force receiving portion for receiving a force and moving the developing container between a first position in which a developing operation is performed by the developer carrying member and a second position in which the developing operation is not performed, wherein the capacitance can be detected in the second position, and the detecting member is a rotatable developer supplying member for supplying the developer to the developer carrying member, the developer supplying member including a foam layer in which the developer can enter.

Developing apparatus

A developing apparatus, including: a developing container which has an opening portion and contains a developer; a developer carrying member which carries the developer at the opening portion; and a rotatable developer supplying member which is in contact with the developer carrying member and has a surface of a foam layer, for supplying the developer to the developer carrying member, the developer supplying member detecting a capacitance between the developer carrying member and the developer supplying member, wherein a surface aeration amount L (liter/min.) of the developer supplying member satisfies 1.8&#x2266;L.

Developing apparatus and image forming apparatus including the same

An image forming apparatus includes a rotatable image bearing member on which an electrostatic latent image is formed; a charging member for being supplied with a charging voltage which is a DC voltage not having an AC voltage component and for contacting the bearing member to electrically charge a surface of the bearing member using an electric discharge; a transfer member for transferring onto a transfer material a toner image formed on the surface of the bearing member by developing the electrostatic latent image, at a transfer position; wherein the charging potential of the charging member is different between when the charging member provides a first region with a potential and when the charging member provides a second region with a potential, thus providing a predetermined potential difference between the first region and the second region, and wherein the transfer member is not supplied with a voltage when the second region is at the transfer position, where the first region is a region on the image bearing member which has been charged by the charging member and which is to be an image forming region, and the second region is a region of the image bearing member which is a non-image-forming region in an immediately previous rotation of the image bearing member and which corresponds to the first region on the bearing member.

Image forming apparatus with a predetermined potential difference between regions of an image bearing member

A charging device for electrically charging an image bearing member, includes a contact charging member contactable to the image bearing member to charge the image bearing member, the contact charging member being supplied only with a DC voltage; and a contact member contacted to the charging member, wherein the image bearing member is adapted to carry a toner image of toner which contains an externally added material comprising silica, wherein work functions of the charging member, the contact member and the silica satisfy,(the work function of the contact member)&#x3e;(the work function of the silica)&#x3e;(the work function of the charging member).

Charging device including a contact charging member with silica thereon, process cartridge including a contact charging member, and image forming apparatus including such charging member

An image forming apparatus includes a rotatable image bearing member on which an electrostatic latent image is formed, a charging member, and a transfer member. A charging potential of the charging member is different between when the charging member provides a first region on the image bearing member with a potential and when the charging member provides a second region on the image bearing member with a potential, thus providing a predetermined potential difference between the first region and the second region. A third region on the image bearing member, with the transfer member being supplied with a voltage to provide a predetermined potential difference between a potential of the third region before being charged by the charging member and a potential of the third region after being charged by the charging member.

Image forming apparatus wherein an image forming region and a non-image forming region are charged with different potentials

An electrophotographic image forming apparatus for forming an image on a recording material, to which a cartridge is detachably mountable. The cartridge includes portion for accommodating a developer for developing an electrostatic latent image formed on an electrophotographic photosensitive member, a roller for developing the electrostatic latent image with the developer, an opening for supplying the developer to the developing roller from the developer accommodating portion, and a sealing member for unsealably sealing the developer supply opening. The apparatus includes a detector for detecting that amount of the developer deposited on a member to be detected is less than a predetermined level, a retractor for producing an electric signal for retracting the sealing member from a sealing position where the sealing member seals the developer supply opening, when the detector detects that amount of the developer deposited on the member to be detected is less than the predetermined level.

Image forming apparatus and seal retractor

A developing apparatus including: a developer carrying member for carrying a developer, the developer carrying member being provided with an elastic layer and adapted to develop, with a developer, an electrostatic image formed on an image bearing member; wherein the developer includes a toner, the toner has a shape factor SF-1 of 100 or more but less than 130, the toner has a storage modulus G' (140&#xb0; C.) at 140&#xb0; C. of 2.0&#xd7;10dN/mor more but less than 2.0&#xd7;10dN/m, the toner has a temperature, when the toner has a viscosity of 1.0&#xd7;10Pa&#xb7;s in a flow tester temperature elevation method, of 115&#xb0; C. or more but less than 130&#xb0; C., and, in a surface roughness of the developer carrying member, a center-line mean roughness Ra, a ten-point mean roughness Rz and a mean spacing Sm of irregularities satisfy following relationships (1): 

A color electrophotographic image forming apparatus for forming an image on a recording material, includes (i) a mounting portion for detachably mounting process cartridges developing images with different colors and each including an electrophotographic photosensitive drum and a developing roller for developing an latent image formed on the drum, wherein roller is movable between a contact state contacting the drum and a spaced state spaced from the drum; (ii) a switching device switching the rollers between the contact and spacing states; (iii) a feeding belt for feeding the recording material along all of the drums; (iv) a controller for switching between a first monochrome mode in which the belt contacts all of the drums and a second monochrome mode in which the belt contacts only the drum of the cartridge which develops the latent image for image formation.

Image forming apparatus switching developing rollers of mounted process cartridges between contact and spaced states and switching the contact position of a feeding belt contactable to drums of the mounted cartridges

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Numazu, Japan

Shinya Yamamoto