Canon Kabushiki Kaisha

Kazuhisa Shida

Takashi Anezaki

Nobuhiro Nakamura

Atsushi Fujii

Haruyuki Tsuji

Hideaki Matsuoka

Atsushi Okuda

Harunobu Ogaki

Kazunori Noguchi

Shio Murai

Hiroyuki Tomono

Takayuki Kanazawa

Yuta Isobe

Shunsuke Mizukoshi

Takeshi Murakami

Kazumichi Sugiyama

Masashi Nishi

Makoto Tokudome

Kazuhiro Yamauchi

Tsutomu Nishida

Yuka Ishiduka

Kenichi Kaku

Yuichi Kikuchi

Hiroki Tanaka

Hiroyuki Watanabe

Nobuo Oshima

Hirofumi Kumoi

Seiichi Shinohara

Makoto Fukatsu

Hideharu Shimozawa

Motonari Ito

Kuniaki Tamagaki

Akihisa Matsukawa

Ryosuke Kanai

Takashi Koyanagi

An image forming apparatus includes a developer carrying member that bears and conveys developer. The developer carrying member has at least a base and a surface layer, with the surface layer having an electron donating portion that mainly donates charge to the developer when the developer and the surface layer make frictional contact to exchange charge and an electron accepting portion that mainly accepts charge from the developer when the developer and the surface layer makes frictional contact to exchange charge. A controller applies an AC voltage to the developer carrying member during a period in which an image forming operation is not performed and the developer carrying member is driven, with the AC voltage being different from that applied during an image forming period, and a rotating speed of the developer carrying member during a non-image forming period is slower than that during an image forming period.

Image forming apparatus having toner charging

There is provided a process cartridge detachably attachable to a main body of an electrophotographic apparatus, the process cartridge including an electrophotographic photosensitive member and a charging member, wherein an outer surface of the charging member is composed of at least a matrix and at least a part of domains, a volume resistivity of the matrix is 1.0&#xd7;10times or more of a volume resistivity of the domain, an average value Sd of circle equivalent diameters of the domains observed on the outer surface of the charging member is in a predetermined range, the electrophotographic photosensitive member contains a support, a photosensitive layer, and a protective layer in this order and when a surface roughness of the protective layer is measured, each of a protruding valley portion Rvk, a load length ratio Mr2, and Sd/Rvk is in a predetermined range.

Process cartridge and electrophotographic apparatus using the same

An image forming apparatus includes a rotatable photosensitive member including a photosensitive layer and a light transmitting surface layer provided outside the photosensitive layer; an exposing unit configured to expose the surface of the photosensitive member to a laser beam which deflects in a main scan direction substantially perpendicular to a moving direction of the surface of the photosensitive member, so that a latent image formed on the surface of the photosensitive member in the main scan direction; and a controller configured to control a pulse width of an image signal for switching, on the basis of image data, between projection and non-projection of the beam from the exposing unit. The controller controls the pulse width such that it is smaller than when the thickness of the surface layer is larger.

Image forming apparatus

An electrophotographic photosensitive member that can not easily cause charging lines even where it is an electrophotographic photosensitive member employing as a conductive layer a layer containing metal oxide particles is disclosed. Also disclosed are a process cartridge and an electrophotographic apparatus which have such an electrophotographic photosensitive member. The electrophotographic photosensitive member has a conductive layer which contains titanium oxide particles coated with tin oxide doped with phosphorus or tungsten.

Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

A configuration in which an opening is covered with a plurality of partition members is provided, and timings of causing the partition members to move are differentiated, so that torque is reduced.

Developer container, developing device, process cartridge, and image forming apparatus

Provided is a developer container, including: a frame body having an opening; a sealing member configured to seal the opening; an unsealing member configured to unseal the opening by moving the sealing member and accommodated inside the frame body; and a part of the sealing member peelably bonded to an outer peripheral edge of the opening on an opposite side of the unsealing member with respect to the opening.

The disclosed structure includes a belt-shaped conveying member configured to convey developer. The conveying member includes a partitioning portion, which is a partition for developer contained in a casing with respect to a conveying direction in which the developer is conveyed, wherein, when the developer container is new, a first developer amount which is an amount of the developer contained at an upstream side that is upstream of the partitioning portion in the conveying direction, is larger than a second developer amount which is an amount of the developer contained at a downstream side that is downstream of the partitioning portion in the conveying direction.

Developer container, development apparatus, process cartridge, and image forming apparatus

A developer container includes a container, provided with an opening and configured to accommodate a developer; a sealing member configured to cover the opening; and an unsealing member configured to unseal the opening by moving the sealing member. The sealing member opposes the container at a central opposing portion positioned in a central side and at an end opposing portion positioned at an end side with respect to a longitudinal direction of the unsealing member. The sealing member and the container are bonded to each other at bonding portion which is at least a part of the central opposing portion. The bonding force at the bonding portion of the central opposing portion is larger than a bonding force between the sealing member and the container at the end opposing portion.

Developer container, cartridge and image forming apparatus

A conductive layer contains a binder material, a first particle, and a second particle. The first particle is composed of a core particle and aluminum-doped zinc oxide covering the core particle or is composed of a core particle and oxygen-deficient zinc oxide covering the core particle. The second particle is of the same material as that of the core particle of the first particle. The content of the first particle is 20% by volume or more and 50% by volume or less of the total volume of the conductive layer. The content of the second particle is 0.1% by volume or more and 15% by volume or less of the total volume of the conductive layer and is 0.5% by volume or more and 30% by volume or less of the volume of the first particle.

A conductive layer of an electrophotographic photosensitive member includes a binder material, a first metal oxide particle, and a second metal oxide particle. The first metal oxide particle is a zinc oxide particle or tin oxide particle coated with tin oxide doped with phosphorus, tungsten, niobium, tantalum, or fluorine. The second metal oxide particle is an uncoated zinc oxide particle or tin oxide particle. The content of the first metal oxide particle is not less than 20% by volume and not more than 50% by volume based on the total volume of the conductive layer. The content of the second metal oxide particle is not less than 0.1% by volume and not more than 15% by volume based on the total volume of the conductive layer, and not less than 0.5% by volume and not more than 30% by volume based on the content of the first metal oxide particle.

A conductive layer of an electrophotographic photosensitive member contains a first metal oxide particle, a second metal oxide particle, and a binder material. The first metal oxide particle is a zinc oxide particle or tin oxide particle coated with tin oxide doped with phosphorus, tungsten, fluorine, niobium, or tantalum, and the second metal oxide particle is a tin oxide particle doped with an element selected from the group consisting of phosphorus, tungsten, fluorine, niobium, and tantalum, the element being the same as the element with which the tin oxide of the first metal oxide particle is doped. The conductive layer satisfies formulae (1) and (2)2&#x2266;{()/()}&#xd7;100&#x2266;25&#x2003;&#x2003;formulae (1):15&#x2266;{()+()}&#xd7;100&#x2266;45&#x2003;&#x2003;formulae (2).

An electrophotographic photosensitive member in which a leak hardly occurs, and a process cartridge and electrophotographic apparatus having the same are provided. The conductive layer in the electrophotographic photosensitive member includes a binder material, a first metal oxide particle, and a second metal oxide particle. The first metal oxide particle is a titanium oxide particle coated with tin oxide doped with phosphorus, tungsten, niobium, tantalum, or fluorine, and the second metal oxide particle is an uncoated titanium oxide particle. The contents of the first and second metal oxide particles in the conductive layer is 20 to 50 vol. % and 1.0 to 15 vol. %, respectively based on the total volume of the conductive layer. The content of the second metal oxide particle in the conductive layer is 5.0 to 30% by volume based on the content of the first metal oxide particle in the conductive layer.

Provided are an electrophotographic photosensitive member in which a residual potential hardly increases at the time of image formation, a pattern memory hardly occurs, and the crack of a conductive layer hardly occurs, and a process cartridge and an electrophotographic apparatus each including the electrophotographic photosensitive member. To this end, the conductive layer of the electrophotographic photosensitive member contains a titanium oxide particle coated with tin oxide doped with phosphorus, a tin oxide particle doped with phosphorus, and a binding material, and when a total volume of the conductive layer is represented by V, a total volume of the titanium oxide particle coated with tin oxide doped with phosphorus in the conductive layer is represented by V, and a total volume of the tin oxide particle doped with phosphorus in the conductive layer is represented by V, the V, the V, and the Vsatisfy the following expressions: 2&#x2266;{(V/V)/(V/V)}&#xd7;100&#x2266;25 and 15&#x2266;{(V/V)+(V/V)}&#xd7;100&#x2266;45.

A method for producing an electrophotographic photosensitive member in which leakage hardly occurs is provided. For this, in the method for producing an electrophotographic photosensitive member according to the present invention, a coating liquid for a conductive layer is prepared using a solvent, a binder material, and a metallic oxide particle having a water content of not less than 1.0% by mass and not more than 2.0% by mass; using the coating liquid for a conductive layer, a conductive layer having a volume resistivity of not less than 1.0&#xd7;10&#x3a9;&#xb7;cm and not more than 5.0&#xd7;10&#x3a9;&#xb7;cm is formed; the mass ratio (P/B) of the metallic oxide particle (P) to the binder material (B) in the coating liquid for a conductive layer is not less than 1.5/1.0 and not more than 3.5/1.0; and the metallic oxide particle is selected from the group consisting of a titanium oxide particle coated with tin oxide doped with phosphorus, a titanium oxide particle coated with tin oxide doped with tungsten, and a titanium oxide particle coated with tin oxide doped with fluorine.

Growing community of inventors

Kawasaki, Japan

Kazuhisa Shida