Ricoh Company, Ltd.

Tadayuki Oshima

Hiroki Furubayashi

Makoto Nakamura

Yutaka Narita

Taisuke Tokuwaki

Tadaaki Hattori

Toshio Kojima

Akiko Tanaka

Satoshi Terashima

Taisuke Tokuwakt

A charge element includes an element body in parallel to a photoreceptor element and biased to the photoreceptor element by an elastic element, and a gap retainer unit provided on the element body, contacting with an outer face of the photoreceptor element to constantly retain a gap between an outer face of the element body and the outer face of the photoreceptor element, and comprising a first gap retainer element provided on the element body and a second gap retainer element provided on the first gap retainer element and made of a material softer than that of the first gap retainer element and that of the outer face of the photoreceptor element.

Charge element, process cartridge, and image forming apparatus

A charging member, includes: an electrically-conductive support; an electrical resistance adjustment layer having ion conductivity provided on the electrically-conductive support; an intermediate layer having ion conductivity provided on the electrical resistance adjustment layer; and a surface layer having insulation provided on the intermediate layer, wherein the intermediate layer is formed of a resin composition containing at least a polyether polyol resin, and the surface layer is formed of a resin composition containing at least one of a fluorine-based resin, a silicone-based resin, a polyamide resin, a polyester resin, and a urethane resin.

Charging member, charging device including the charging member, process cartridge including the charging device and image forming apparatus including the process cartridge

A charging member is provided in which a minute gap between an image support body and the charging member is set widely but even so the charging member does not abnormally discharge easily, the charging member includes a conductive support body, an electrical resistance adjustment layerdisposed on the conductive support bodyand a surface layerdisposed on the electrical resistance adjustment layerin which the surface layer contains at least (a) polyol resin grafted with fluorine or silicon, (b) polyether polyol resin, (c) organic anion salt that contains fluorine and alkali metal or alkali earth metal and (d) polyisocyanate.

A conductive member includes a conductive support and an electrical resistance adjusting layer formed on the conductive support. The electrical resistance adjusting layer includes a thermoplastic resin, a polymeric ion conductive material, and a graft copolymer which is compatible with both of the thermoplastic resin and the polymeric ion conductive material. The electrical resistance adjusting layer is formed in a sea-island structure formed from a sea portion made of the polymeric ion conductive material and island portions made of the thermoplastic resin, the island portions being dispersed in the sea portion and each of the island portions is formed in an elongate shape. A layer made of the graft copolymer is formed at boundaries between the thermoplastic resin and the polymeric ion conductive material.

Conductive member, process cartridge, and image forming apparatus

An electroconductive member including an electroconductive support, an electric resistance adjusting layer formed on the electroconductive support, and a top surface layer that coats the surface of the electric resistance adjusting layer, the top surface layer containing at least one oxygen-containing inorganic compound selected from among a composite oxide of silicon and aluminum, an oxygen-containing silicon compound, and an oxygen-containing aluminum compound.

Electroconductive member, process cartridge, and image forming apparatus

A conductive member includes, a conductive supporting body, an electric resistance-adjusting layer formed in the conductive supporting body, and a space holding member which is formed on each end of the electric resistance-adjusting layer and has a material different from a material of the electric resistance-adjusting layer, the space holding member constantly maintaining a space between an image carrier and the electric resistance-adjusting layer, and the electric resistance-adjusting layer including a resin composition having a thermoplastic resin (A) containing at least an ether group, a fibrous polymer (B), which do not melt in (A) and has an aromatic skeleton in a molecule, and an electrolyte salt (C).

Conductive member, process cartridge using the conductive member, and image forming device using the process cartridge

A conductive member () includes a conductive supporting body (), an electric resistance adjusting layer (), which is formed onto the conductive supporting body () and is disposed to face a photoconductor (), and a pair of space holding members () disposed in both ends of the electric resistance adjusting layer (), so as to have contact with the photoconductor () to maintain a predetermined gap (G) between the electric resistance adjusting layer () and the photoconductor, and each of the space holding members () includes a cylinder portion () attached to the outer circumference surface () of the electric resistance adjusting layer and an end plate () provided in one end portion of the cylinder portion and disposed to have contact with the end surface () of the electric resistance adjusting layer.

Conductive member, process cartridge having the same, and image forming apparatus having the process cartridge

A conductive member includes a conductive supporting member provided facing an image bearing member and including a continuous or discontinuous fixing groove provided in the vicinity of each of both ends of the conductive supporting member in a peripheral direction thereof, an electrical resistance adjusting layer formed on the conductive supporting member and including a step portion which includes at least one step disposed in the vicinity of each of the both ends of the electrical resistance adjusting member, and gap retainers each provided to the step portion and including a cylinder portion which contacts at least one surface of the step portion, and an end plate so that a predetermined gap is formed between the image bearing member and the electrical resistance adjusting layer. The end plate contacts at least one surface of the step portion and fits into the fixing groove.

Conductive member, process cartridge including same, and image forming apparatus including the process cartridge

The charge assembly according to the present invention includes a charge member having a conductive support body on which a resistance adjusting layer and a surface layer covering the resistance adjusting layer are formed, to rotate a surface of the image support body to electrically charge the image support body, the surface layer having a static friction coefficient of 1.0 or more; and a cleaning member rotating the surface layer of the charge member in contact therewith to remove foreign particles on the surface layer.

Charge assembly and image formation apparatus including the same

A conductive member includes a conductive supporter, an electric resistance adjusting layer formed on the conductive supporter and gap retaining members which are of a different material from that of the electric resistance adjusting layer and are disposed respectively at both ends of the electric resistance adjusting layer for contacting an image carrier so as to maintain a predetermined gap between the electric resistance adjusting layer and the image carrier, wherein the electric resistance adjusting layer is made from a resin composition containing a thermoplastic resin containing an ether group, an organic phosphonium salt and a fluorine-containing organic anion salt.

Conductive member, process cartridge using conductive member, and image forming apparatus using process cartridge

The present invention provides a conductive memberwith a superior durability by controlling an electric resistance value of an electric resistance adjusting layerwithin a semi conductive range, preventing an ion conductive material from bleeding out of the electric resistance adjusting layerto avoid improper charging and avoiding strength decreasing of a weld portion of the electric resistance adjusting layer and an electric resistance value fluctuation. The electric resistance adjusting layeris made from a resin composition prepared by melting and kneading a thermoplastic resin, a high molecular ion conductive material containing an alkali metal salt and a graft copolymer which has an affinity for both the thermoplastic resin and the high molecular ion conductive material.

Conductive member, process cartridge using conductive member and image formation apparatus using process cartridge

A conductive member including a conductive supporting body (), an electric resistance adjusting layer () formed on the conductive supporting body (), and space holding members () provided on opposite ends of the electric resistance adjusting layer (), at least one engaging projection () being provided on one of the electric resistance adjusting layer () and each of the space holding members (), and an engaging opening () in which the engaging projection is inserted being provided in the other of the electric resistance adjusting layer () and each of the space holding members ().

Conductive member and process cartridge having it and image forming apparatus having the process cartridge

A conductive member to be disposed so as to abut on an image carrier is provided. The conductive member includes an elongate conductive supporter, an electrical resistance adjusting layer formed on a circumferential surface of the supporter, and a pair of gap maintaining members provided respectively to the two ends of the adjusting layer. A gap with a certain clearance between an outer circumferential surface of the adjusting layer and an outer circumferential surface of the image carrier provided in parallel to the adjusting layer is formed. A stepped portion is formed in a joint section between the adjusting layer and each of the gap maintaining members with the joint section. An inclination is formed so as to be continuously inclined from the outer circumferential surface of each of the gap maintaining members to the outer circumferential surface of the adjusting layer in the stepped portion.

Conductive member, process cartridge having conductive member, and image forming apparatus having process cartridge

An conductive member includes a long conductive supporting body to which a predetermined potential is applied, extending from one side to the other side, an electric resistance adjusting layer, which is formed to surround a circumference surface of the conductive supporting body and adjusts an electric resistance, and a surface protection layer, which is provided to cover a surface of the electric resistance adjusting layer and protects the surface of the electric resistance adjusting layer, and the electric resistance adjusting layer contains a thermoplastic resin material having an ether group in a molecular and an organic phosphonium salt.

Conductive member, charging member using the conductive member, process cartridge using the charging member and image forming apparatus using process cartridge

An electrical conductive member is configured to prevent a shape distortion in gap retaining members caused by that the gap retaining members are fitted to an end surface of an electric resistance adjusting layer, and to be able to maintain a gap between the electric residence adjusting layer and an image carrier for a long-term in a constant state with a high accuracy.

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Atsugi, Japan

Tadayuki Oshima