Canon Kabushiki Kaisha

Masataka Kodama

Noriko Suzumura

Noriyuki Doi

Hiroki Masu

Noriaki Kuroda

Kineo Takeno

Kenichi Yamauchi

Hiroshi Mayuzumi

Masahiro Kurachi

Tomohito Taniguchi

Yuya Tomomizu

Hiroshi Satoh

Taichi Sato

Hidekazu Matsuda

Atsushi Uematsu

Takehiko Aoyama

Satoshi Koide

Yusuke Yagisawa

Mototeru Goto

Nozomu Takahata

The electrophotographic roller has a surface layer comprising an electro-conductive elastic layer on an electro-conductive substrate. The opening of a bowl-shaped resin particle is exposed on the surface of the electrophotographic roller. The number of contact portions of the convex portion with the glass plate in a square region where a length of a nip in a direction along the circumferential direction of the electrophotographic roller of a nip formed by pressing the roller on the glass plate with a specific load applied as the length of one side and is located at any position in the nip is 8 or more. The average value of the areas of the contact portions is 10 &#x3bc;mto 111 &#x3bc;m. The variation coefficient of the areas of the contact portions and the variation coefficient D of the areas of a plurality of Voronoi regions each including a contact portion satisfy specific relationships.

Electrophotographic roller, process cartridge and electrophotographic apparatus

A charging member is provided having an electroconductive substrate, and a resin layer on the substrate, in which the charging member has an area on the surface of the charging member, the area including a compound represented by the following formula (1), 

Charging member, process cartridge, and electrophotographic apparatus

A charging member which has high charging ability and prevents generation of abnormal discharge is provided. The charging member includes a support and a surface layer. The surface layer contains a polymetalloxane having a specific structure.

Charging member, process cartridge and electrophotographic apparatus

Provided is a charging member that suppresses the occurrence of abnormal discharge under low temperature and low humidity. The charging member includes a support and a surface layer on the support, and the surface layer contains a compound represented by the following formula (a), (b), (c), or (d). 

Charging member, process cartridge, and electrophotographic image forming apparatus

A charging member is provided which can prevent electrostatic adhesion of a toner and/or an external additive of the toner to the surface of the charging member, and exhibits stable charging performance during long-term use. The charging member comprises a support, and a surface layer on the support, and the surface layer comprises a polymetalloxane containing at least one metal atom selected from the group consisting of aluminum, titanium, zirconium and tantalum, and a specific group which is bonded to the at least one metal atom in the polymetalloxane.

Charging member, process cartridge and electrophotographic image forming apparatus

There is provided a charging member capable of preventing the occurrence of abnormal discharge at low temperature and low humidity, and capable of preventing the occurrence of an image defect due to abrasion. The charging member includes a support and a surface layer on the support, and the surface layer contains a specific compound.

Provided is a method of producing a member for electrophotography capable of providing a high-quality electrophotographic image. The method of producing a member for electrophotography is a method of producing a member for electrophotography having an electro-conductive support, an elastic layer, and a surface layer, the method comprising: a first step of forming, on a surface of the elastic layer, a coat of a surface-layer coating liquid containing a hydrolyzed condensate of a hydrolyzable silane compound and a chelate titanium compound represented by the following general formula (2); and a second step of crosslinking the hydrolyzed condensate in the coat through cleavage of an epoxy group in the hydrolyzed condensate to form the surface layer: 

Method of producing member for electrophotography

There is provided a charging member having charging performance that is not easily changed even by long-term use. The charging member includes an electro-conductive support, an elastic layer, and a surface layer. The elastic layer contains particles in such a manner that at least a part of the particles are exposed from the elastic layer, and thus a surface of the elastic layer is roughened. The particles are high-molecular-weight polyethylene particles. The surface of the elastic layer is covered with the surface layer in such a manner that the surface shape of the elastic layer is reflected in the surface shape of the charging member. The surface layer contains a high-molecular compound having a specific constitutional unit.

Charging member and electrophotographic apparatus

A charging member is provided which can not easily cause vibration and can stably charge a photosensitive member, even where a high-frequency alternating-current voltage is applied thereto. It is a charging member having an electrically conductive substrate, an electrically conductive elastic layer and a surface layer, and the elastic layer has, in the order from the substrate side, a first rubber layer and a second rubber layer laminated to the first rubber layer, and, where the natural vibration frequency of the first rubber layer is represented by fand the natural vibration frequency of the second rubber layer is represented by f, has a natural vibration frequency ratio, f/f, of from 2.35 or more to 10.0 or less.

Provided a charging member which can prevent any contaminants deposited on a cleaning member from adhering thereto by making low a surface free energy and coefficient of friction thereof. The charging member has a substrate, an elastic layer and a surface layer, and the surface layer contains a polymer having an Si&#x2014;O&#x2014;W linkage; the polymer having a constitutional unit represented by the following formula (1) and a constitutional unit represented by the following formula (2): 

Charging member, process for its production, process cartridge and electrophotographic apparatus

Provided are the following charging member and a method of producing the charging member. The charging member has an improved charging ability and hence alleviates, in particular, a positive ghost. The charging member can maintain resistance to the adhesion of toner, a toner external additive, or the like over a long time period. The charging member for an electrophotographic apparatus comprises an electro-conductive support, an electro-conductive elastic layer, and a surface layer, wherein the surface layer comprises a polymer compound having an Si&#x2014;O&#x2014;Ti linkage in a molecular structure thereof, and the polymer compound has each of constitutional units represented by a formula (1), a formula (2), and a formula (3) defined in the description. The method is a method of producing the charging member.

Charging member and method of producing the member, process cartridge, and electrophotographic image-forming apparatus

Provided is the following charging member of an electrophotographic apparatus. The charging member suppresses the occurrence of each of a streak-like image, a spot-like image, and a rough image that occur when image formation is performed over a long time period. Also provided are a process cartridge and an electrophotographic apparatus each having the charging member. A compound having a siloxane dendrimer structure at a vinyl group or a side chain of a vinyl polymer is incorporated into the surface layer of the charging member comprising a conductive substrate and the surface layer.

A charging member electrically charges a member to be charged in a state that said charging member forms a nip with the member to be charged and electroconductive particles are present at the nip. The charging member includes an elastic foam member provided at a surface of said charging member. The elastic foam member includes cell portions and cell wall portions defining the cell portions. The cell wall portions have a thickness proportion to the cell portions of not less than 2% and not more than 40%.

Charging member, charging apparatus and image forming apparatus

A charging device is formed of a member to be charged, a charging member disposed so as to form a nip with the member to be charged, and electroconductive particles disposed so as to be present at the nip between the photosensitive member and the member to be charged. A uniform direct injection charging performance is realized by providing the charging member with a fine network-textured surface having concave cells giving a total cell edge perimeter per unit area of 15 mm/mm to 60 mm/mm .

Growing community of inventors

Mishima, Japan

Masataka Kodama