Canon Kabushiki Kaisha

Minolta Company, Ltd.

Ricoh Company, Ltd.

Konica Minolta Business Technologies, Inc.

Olympus Corporation

Olympus Optical Company, Ltd.

Canon Kabushiki Tokyo

Minoru Nakamura

Masahiro Anno

Katsunori Kurose

Chikara Tsutsui

Atsushi Yamamoto

Kazuaki Nagaoka

Ryo Sugiyama

Yoshihiro Mikuriya

Hiroyuki Fukuda

Chiyoshi Nozaki

Masahide Inoue

Tsuyoshi Nozaki

Kazutoshi Ishida

Hideaki Yasunaga

Takuya Kadota

Masaki Yamada

Masayuki Hagi

Kunimasa Kawamura

Shohei Urushihara

Toru Ishii

Yoshimichi Ishikawa

Yuji Sakurai

Makoto Kobayashi

Akira Izutani

Kenta Matsunaga

Arihiro Yamamoto

Hiroaki Katoh

Hiroaki Kato

Takashi Koyanagi

Seiji Tsuru

Hiroshi Morishita

Yuto Miyauchi

Takashi Kusaba

Masahiro Kurachi

Junichi Tamaoki

Sosuke Yamaguchi

Noriyuki Doi

Ryota Kashiwabara

Fumihiko Utsuno

Yoshiyuki Takayama

Atsushi Tanaka

Yuki Yamamoto

Takuya Kitamura

Takeshi Suzuki

Masahiro Watanabe

Yuji Kawaguchi

Yoshitaka Sekiguchi

Taichi Sato

Takahiro Kawamoto

Kazunari Hagiwara

Kentarou Nakamura

Kentaro Yamawaki

Takayuki Namiki

Yasushi Katsuta

Takeshi Arai

Takashi Mukai

Mitsuyo Matsumoto

Kazuhito Wakabayashi

Yasukazu Ikami

Kouki Yano

Tomoya Uesugi

Hidenori Satoh

Hiroyuki Murakami

Masashi Uno

Wataru Moriai

Shigeyuki Hakumoto

Yasuaki Ushio

Yosuke Ata

Akio Nishi

Masahiro Inami

Masayasu Hagi

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

An objective optical system includes in order from an object side to an image side, a first lens group having a negative refractive power, a second lens group, and a third lens group having a positive refractive power. At a time of focusing, the second lens group moves in an optical axial direction. The third lens group includes, from the object side to the image side, a front group and a rear group. The front group includes a cemented lens having a positive refractive power or includes a single lens having a positive refractive power. The rear group includes a cemented lens having a positive refractive power, and the following conditional expression (1) is satisfied:0.45&#x3c;332&#x3c;0.8&#x2003;&#x2003;(1).

Objective optical system and endoscope

A developer bearing member including: a rotational shaft; and an elastic layer on an outer circumference surface of the rotational shaft, developer being borne on a surface of the elastic layer, wherein the elastic layer is configured such that a load per unit area of a contact portion between one surface of a flat glass plate and the surface of the elastic layer is to be 5.8 N/mmor more, in a state that the one surface of the flat glass plate being parallel with an axis direction of the rotational shaft and the one surface of the flat glass plate coming into contact with the surface of the elastic layer with a predetermined penetration level, and wherein a ten-point average roughness Rzjis on the surface of the elastic layer is greater than a volume-average particle diameter of a particle of the developer.

Developer bearing member, developing apparatus, process cartridge, and 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

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

The developing member has an electroconductive substrate, and an elastic layer having a mono-layer structure on the substrate as a surface layer, wherein the elastic layer has a thickness of T &#x3bc;m and a volume resistivity of 1.0&#xd7;10&#x3a9;&#xb7;cm to 1.0&#xd7;10&#x3a9;&#xb7;cm, and includes a first resin as a main binder; and the elastic layer further includes a second resin having a structural unit represented by Formula (1), in a region extending toward a first surface from a second surface by a depth of t &#x3bc;m, where the first surface is defined as a surface of the elastic layer on a side facing the substrate, and the second surface is defined as a surface thereof opposite to the first surface, wherein in the region, a concentration of ether bonds is higher on the second surface side than on the first surface side (provided that T&#x3e;t): 

Developing member, process cartridge, and electrophotographic 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%.

Electrophotographic member having elastic layer with elastic modulus of 0.5 to 3.0 MPA and coating layer with elastic modulus of 5.0 to 100 MPA

The developing member includes a substrate, and an electroconductive layer on the substrate, wherein the electroconductive layer has electrically insulating domains on an outer surface thereof, the domains being independent from each other, the developing member has an outer surface including a surface of the electroconductive layer and surfaces of the domains, and wherein, when each of the domains is orthographically projected onto the surface of the electroconductive layer, defining respective areas of projected images of the domains as S, and defining respective areas of convex envelopes of the projected images as H, at least one domain satisfies the relation represented by 0.05&#x2264;S/H&#x2264;0.80.

Developing member having outer surface with independent electrically insulating domains, electrophotographic process cartridge, and electrophotographic image forming apparatus

Provided is a developing roller comprising an electroconductive substrate and an electroconductive layer thereon, the electroconductive layer retaining resin particles so that at least a part of each of the resin particles is exposed on an outer surface of the developing roller; the outer surface of the developing roller constituted by electrically insulating domains and an electroconductive matrix, assuming that a square region 200-&#x3bc;m in a side is put on the outer surface of the developing roller, the square region including the domains, among the domains in the square region at least two of them satisfying specific condition, and assuming that the outer surface of the developing roller is charged, and creating a potential map of the charged outer surface of the developing member, the two domains satisfying the specific condition being ascertained in the potential map.

The electrophotographic member comprises: an electroconductive substrate; and an electroconductive layer on or above the substrate, an outer surface of the electrophotographic member having electrically insulating first regions and an electroconductive second region, each of the first regions being adjacent to the second region, wherein assuming that a square region having a side length of 300 &#x3bc;m is put on an outer surface of the electrophotographic member, in the square regions, the first regions are included, and assuming that Voronoi tessellation is conducted with respect to the first regions in the square region to create Voronoi polygons, a coefficient of variation of S/SV is from 0.10 to 1.00, where SV denotes a plane area of each of the Voronoi polygons, and Sdenotes a plane area of one of the first regions included in each of the Voronoi polygons.

Provided is an electrophotographic member which can suppress adhesion of the toner component and fogging even in the case of printing a large number of sheets. The electrophotographic member includes an electroconductive support and an elastic layer and has convex portions composed of the elastic layer on a surface of the electrophotographic member and a filled portion containing a resin at a valley portion between the convex portions, the filled portion has a height lower than heights of the convex portions, and the surface of the electrophotographic member has a specific Martens hardness.

Electrophotographic member, process cartridge, and electrophotographic image forming apparatus

Growing community of inventors

Mishima, Japan

Minoru Nakamura