Canon Kabushiki Kaisha

Yukinori Nagata

Jun Murata

Toshiro Suzuki

Takumi Furukawa

Noriaki Kuroda

Toshinari Miura

Hisao Kato

Yoko Kuruma

Masaki Ozawa

Michitaka Kitahara

Kazuyuki Shishitsuka

Yoshiaki Nishimura

Hiroshi Mayuzumi

Nobutoshi Hayashi

Koji Yamaguchi

Satoru Yamada

Hiroomi Matsuzaki

Taichi Sato

Masaaki Harada

Akiya Kume

Yoshiyuki Beniya

Motomi Suzuki

Kohki Kamata

A roller member used in an image forming apparatus including: a metallic shaft; and a covering layer, wherein the metallic shaft has a cylindrical shape formed so that one end portion and the other end portion of the metallic plate oppose each other, the one end portion and the other end portion each include a straight portion, a projection, and a depression, the projections on the one end portion engage the depressions on the other end portion, a straight area is located outside a projection and depression area in which the projection on the one end portion and the projection on the other end portion are aligned in an axial direction of the metallic shaft, and the projection and depression area is entirely covered with the covering layer and at least part of the straight area is exposed from the covering layer.

Roller member, roller supporting mechanism, and metallic shaft for forming an image with a laser

Provided is a charging member capable of stably charging an object to be charged while suppressing adhesion of toner or an external additive onto a surface of an elastic layer and compression set of an abutting portion of the elastic layer. The charging member is a charging member, comprising a mandrel; and an electro-conductive elastic layer, wherein: the elastic layer has a universal hardness decreasing from a surface toward a depth direction thereof; and the hardnesses at a central portion and both end portions in a longitudinal direction of the charging member satisfy the relationships: in the surface of the elastic layer, the hardnesses at the both end portions are higher than that at the central portion; and at a position having a depth of t (&#x3bc;m) from the surface of the elastic layer, the hardness at the central portion is higher than those at the both end portions.

Charging member, electrophotographic apparatus, and process cartridge

An object of the present invention is to provide a charging member in which a toner, an additive for use in the toner, or the like is hard to adhere to the surface even under repeated use for a long time, and hence the charging and image output are made stable for a long time even if the charging member is used in the DC contact charging method, and a process cartridge and an electrophotographic apparatus having the charging member. The present invention provides a charging member comprising a support, a conductive elastic layer formed on the support, and a surface layer formed on the conductive elastic layer, characterized in that the surface layer contains a polysiloxane having a fluoroalkyl group and an oxyalkylene group, and a process cartridge and an electrophotographic apparatus having the charging member.

Charging member, process cartridge and electrophotographic apparatus

A charging member has a surface layer. The surface layer contains a polysiloxane having a first unit, a second unit and a third unit each of which is represented by a specific formula. The ratio of the sum of the mole numbers of the first and second units to the sum of the mole numbers of the first to third units is in a specific range.

Charging member, process cartridge, and electrophotographic apparatus

A charging member is provided in which a toner, an additive for use in the toner, or the like is hard to adhere to the surface even under repeated use for a long time, and hence the charging and image output are made stable for a long time even if the charging member is used in the DC contact charging method. Also provided are a process cartridge and an electrophotographic apparatus having the charging member. The charging member includes a support, a conductive elastic layer formed on the support, and a surface layer formed on the conductive elastic layer, characterized in that the surface layer contains a polysiloxane having a fluoroalkyl group and an oxyalkylene group, and a process cartridge and an electrophotographic apparatus having the charging member.

In a roller member having at least a mandrel and a conductive elastic layer provided on the peripheral surface of the mandrel, the roller member has a surface roughness Rz jis 94 of from 0.5 &#x3bc;m to 10 &#x3bc;m, and the roller member contains voids in the vicinity of its surface. Substantially all of the voids have an average internal diameter of from 10 &#x3bc;m to 400 &#x3bc;m and an aspect ratio of from 1.3 or more to 10.0 or less, and having an angle of from 0&#xb0; or more to 45&#xb0; or less as an acute angle between an axis that takes the maximum internal diameter of each of the voids and a tangent to a concentric circle of the roller member at the center of each of the voids.

Roller member, and process for its manufacture

A cellular conductive roller has closed cells and open cells with conductive powder filling the open cells of the cellular conductive roller. A method for making a cellular conductive roller includes filling the open cells in the cellular conductive roller with conductive powder, adhering a tacky sheet to the surface of said cellular conductive roller; then peeling said tacky sheet off the surface of said cellular conductive roller. Also disclosed is an electrophotographic device using the cellular conductive roller and a process cartridge into which the cellular conductive roller is integrated.

Cellular conductive roller with conductive powder filling open cells in

A white electroconductive coating composition includes a white pigment having a whiteness of at least 60, a white conductive material having a whiteness of at least 50 and a volume resistivity of at most 1.times.10.sup.10 ohm.cm. The coating composition is suitable to provide a a coating film showing a whiteness of at least 60 and a surface resistivity of at most 1.times.10.sup.11 ohm/cm.sup.2. Such a white conductive layer may be formed on a back side of a surface insulating film of a transfer material carrying member of an electrophotographic image forming apparatus to provide a reference white pattern for detecting a density of a toner image formed on the carrying member, thereby allowing controlled image formation based on the detected density data.

Growing community of inventors

Mishima, Japan

Yukinori Nagata