Canon Kabushiki Kaisha

Ryo Sugiyama

Minoru Nakamura

Kazuaki Nagaoka

Kazutoshi Ishida

Yuji Sakurai

Kenta Matsunaga

Yoshinobu Ogawa

Masashi Uno

Toru Ishii

Mitsuru Okuda

Sosuke Yamaguchi

Shohei Urushihara

Tomoya Uesugi

Fumihiko Utsuno

Noriyuki Doi

Seiji Tsuru

Wataru Moriai

Hiroshi Morishita

Rieko Takabe

Takuya Kitamura

Masamichi Sato

Jun Miura

Masatake Tanaka

Kazunari Hagiwara

Takahiro Kawamoto

Takashi Kusaba

Kentarou Nakamura

Kentaro Yamawaki

Taiji Katsura

Kazuhiro Okubo

Kunimasa Kawamura

Hideya Arimura

Kazuhito Wakabayashi

Kenji Shindo

Takaaki Shinkawa

Shintaro Kawaguchi

Akio Nishi

A process cartridge includes a toner, a regulating member, and a developing roller including a conductive substrate, an elastic layer, and a surface layer which includes a binder resin, a first resin particle having an elastic coefficient of 100 to 10,000 MPa, and a second resin particle having an elastic coefficient of 2 to 50 MPa and in which the outer surface has a first protruded portion and a second protruded portion 5.0 μm or more lower than the first protruded portion and has an average maximum height of 6 to 18 μm. The toner includes a toner particle and an external additive A that is a silica particle having a major diameter of 40 to 400 nm, a surface coverage of the toner particle by the external additive A is 3.0% or more, and a dispersion degree evaluation index D of the external additive A is 2.0 or less.

Process cartridge

A developing device comprising a developing roller in which a vicinity of an outer surface of a surface layer is hardened, a toner supply roller, and a toner, wherein the developing roller has fine particles comprising an organosilicon compound and having a substantially hemispherical shape on the outer surface, a particle diameter of the fine particles is within a specific range, and the toner comprises silica particles as an external additive and a adhesion rate of the silica particles is 50% or more.

Developing device, cleaning method, process cartridge and electrophotographic image forming apparatus

Provided is a developing device including: a toner; and a developer carrying member. The developer carrying member includes an electroconductive substrate and a surface layer on the substrate, the surface layer being a single layer and including a matrix containing a crosslinked urethane resin as a binder, wherein E1 &#x2265;200 MPa and 10 MPa&#x2264;E2 &#x2264;100 MPa, where E1 is an elastic modulus of the matrix in a first region from an outer surface of the surface layer to a depth of 0.1 and E2 is an elastic modulus of the matrix in a second region from a depth of 1.0 to 1.1 &#x3bc;m from the outer surface. The toner includes a toner particle containing a binder resin and a colorant and having a Martens hardness of 85 to 1,100 MPa when measured under a condition of a maximum load of 2.0&#xd7;10N.

Developing apparatus, electrophotography process cartridge, and electrophotographic image forming apparatus

Provided an electrophotographic member capable of causing less fog in an H/H environment even when used in a torque-reduced image forming apparatus. The member comprises an electro-conductive substrate, an electro-conductive layer thereon and insulating parts, the member having a surface having an electrical insulating first region and an electro-conductive second region, the first region and the second region being adjacent to each other, a total area of the second region in a square region put on an outer surface of the member is 30% to 80% of an area of the square region; two or more of the 200 straight lines drawn in the square region at an interval of 5 &#x3bc;m pass the second region at least once, and, the number of line segment LS having a length of 200 &#x3bc;m or more is 5% or less of the total number of the line segment LS.

Electrophotographic member, electrophotographic process cartridge and electrophotographic image forming apparatus

Provided is an electrophotographic member in which density unevenness of an image is less likely to occur even in the case of outputting an image after standing in a high-temperature and high-humidity environment for a long period of time. The electrophotographic member includes: an electroconductive substrate; an electroconductive elastic layer on or above the substrate; and an insulating portion on the elastic layer, an outer surface of the electrophotographic member being composed of an outer surface of the insulating portion and an outer surface of the elastic layer that is not covered with the insulating portion, wherein the elastic layer contains a urethane resin as a first resin, and the elastic layer has a region from the outer surface of the elastic layer constituting the outer surface of the electrophotographic member to a depth of 1 &#x3bc;m, the region further containing a second resin.

Electrophotographic member, electrophotographic process cartridge, and electrophotographic image forming apparatus

The electrophotographic member includes: an electroconductive substrate; and a surface layer having a mono-layer structure, wherein the surface layer has a matrix containing a cross-linked urethane resin as a binder, and when an elastic modulus of the matrix in a first region in a thickness direction from an outer surface of the surface layer to a depth of 0.1 &#x3bc;m from the outer surface of the surface layer is defined as E1, and an elastic modulus of the matrix in a second region in a thickness direction from a depth of 1.0 &#x3bc;m from the outer surface of the surface layer to 1.1 &#x3bc;m from the outer surface of the surface layer is defined as E2, E1 and E2 satisfy the following Expressions (1) and (2), respectively:1&#x2265;200 MPa&#x2003;&#x2003;(1); and10 MPa&#x2264;2&#x2264;100 MPa&#x2003;&#x2003;(2).

Electrophotographic member having a surface layer with a cross-linked urethane resin-containing matrix, process cartridge, and apparatus

The developing roller includes an electro-conductive substrate and a covering layer on the electro-conductive substrate, the covering layer including a matrix and an electro-conductive particle dispersed in the matrix, an arithmetic mean value of the current value is 300 pA or less and the standard deviation of the current value is 0.1-fold or less of the current value, a standard deviation of a potential is 3.0 V or more, and an arithmetic mean value of a volume resistivity is 10&#x3a9;&#xb7;cm or less, and a standard deviation of the volume resistivity is 1-fold or more of the arithmetic mean value of the volume resistivity.

Developing roller, process cartridge and image forming apparatus

A developing roller that enables the image density of electrophotographic images to be kept uniform even when used in an environment at a high temperature and a high humidity for a long period. The developing roller includes an electro-conductive mandrel and an electro-conductive layer on the mandrel, having an outer surface constituted by at least a first region which is electrically insulating, and a second region, the second region having higher electro-conductivity than that of the first region, the first region being arranged adjacent to the second region, the first region being disposed on an outer surface of the electro-conductive layer, the first region having a Vickers hardness of 10.0 or more as measured at an outer surface thereof, and the first region having a fracture toughness value of 800 Pa&#xb7;mor more as measured at the outer surface thereof by an indentation fracture method.

Developing roller, process cartridge and electrophotographic image forming apparatus

A developing roller that suppresses contamination of the surface of a photosensitive member and also obtains a high-quality image. The developing roller includes an electro-conductive substrate, an electro-conductive elastic layer and a surface layer which are stacked in this order, wherein the surface layer has resin particles that are dispersed in a polyurethane matrix, an outer surface of the surface layer has a first protrusion originating in first resin particle and a second protrusion originating in second resin particle, wherein the first resin particle contains polyurethane, an elastic modulus Eof the first resin particle is 100 to 2000 MPa, an elastic modulus Eof the second resin particle is 2 to 50 MPa, a maximum height roughness Rz of the outer surface is 6 to 18 &#x3bc;m, and a peak vertex density Spd is 5.0&#xd7;10to 5.0&#xd7;10(1/mm).

Provided is an electrophotographic developing member capable of sufficiently increasing a density of an image initially output from a standby state. The developing member includes: a substrate; a porous electroconductive elastic layer on the substrate; and an electroconductive solid layer on the electroconductive elastic layer, in which an outer surface of the developing member includes a first region having an electrical insulating surface and a second region having an electroconductive surface, the first region and the second region are arranged to be adjacent to each other, and the first region is constituted by an electrical insulating portion disposed on an outer surface of the electroconductive solid layer.

Developing member, electrophotographic process cartridge, and electrophotographic image forming apparatus

A developing roller is capable of preventing the generation of a difference in image density between a central portion and an end portion of an electrographic image. The developing roller has an electro-conductive mandrel and an electro-conductive layer on the mandrel, the electro-conductive layer has a crown shape in which an outer diameter of a central portion in a direction along the mandrel is larger than outer diameters of both end portions in the direction along the mandrel, an outer surface of the developing roller includes a first region having an electrically insulating property and a second region having a higher conductive property than the first region, and the first region and the second region are disposed adjacent to each other.

Developing roller having crown-shaped electro-conductive layer with outer surface providing electrically insulating first regions adjacent to second regions having higher conductivity

A developing apparatus, includes: a developer bearing member configured to bear a developer; and a regulating member that is disposed in contact with a surface of the developer bearing member, and configured to regulate the developer borne on the developer bearing member. On the surface of the developer bearing member, a conductive portion having a first surface roughness and first electric resistance, and a dielectric portion having a second surface roughness, which is smaller than the first surface roughness, and second electric resistance, which is larger than the first electric resistance, are disposed. In a case where the developer borne on the developer bearing member is charged by friction with the regulating member, a charging polarity of the dielectric portion is the same polarity as a charging polarity of the developer.

Developing apparatus, developer carrying member, process cartridge, and image forming apparatus

To provide a developing roller having improved toner conveying force in a high-temperature and high-humidity environment. The developing roller has a substrate and an electro-conductive layer on the substrate. The outer surface of the developing roller has an electrical insulating first region and an electro-conductive second region adjacent to the first region and at the same time has at least one groove in the first region.

Developing roller, electrophotographic process cartridge and electrophotographic image forming apparatus

Provided is a developing member capable of sufficiently securing a toner conveyance amount, thereby being capable of suppressing a reduction in image density, even when a solid black image or an image having a high print percentage is continuously output. The developing member includes an electro-conductive substrate and an electro-conductive layer thereon, an outer surface of the developing member includes a first, second and third regions, when surface potentials of the respective regions with scanning probe microscope, and measured surface potential of the respective regions are defined as V1, V2, and V3, respectively, V1 is &#x2212;0.70 V to &#x2212;0.50 V, 1.30&#x2264;V1/V2&#x2264;25.00, and V3 is 0.00 V to 0.50 V.

An electrophotographic member has an electro-conductive substrate, an elastic layer on the substrate and a coating layer on the elastic layer. The elastic layer has an elastic modulus of 0.5 MPa to 3.0 MPa and the coating layer has an elastic modulus of 5.0 MPa to 100.0 MPa as measured in an environment of a temperature of 30&#xb0; C. and a relative humidity of 80%.

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Mishima, Japan

Ryo Sugiyama