Ricoh Company, Ltd.

Osada Research Institute, Ltd.

Toshio Kojima

Tadaaki Hattori

Makoto Nakamura

Yutaka Narita

Tadayuki Oshima

Nobuyuki Taguchi

Kyohta Koetsuka

Taisuke Tokuwaki

Hiroki Furubayashi

Noriyuki Kamiya

Masayuki Ohsawa

Takumi Terasaka

Takamasa Ozeki

Yuuki Satoh

Yoshiyuki Takano

Hiroya Abe

Toshiki Hayashi

Katsumi Masuda

Takashi Innami

Rei Suzuki

A development device includes a developer container, a developer carrier, exposed partly from a casing, facing a latent image carrier in a development area, a magnetic field generator inside the developer carrier, having multiple magnetic poles including a conveyance pole to convey the developer downstream from the development area to a developer release portion, a developer agitator, and a developer regulator. A predetermined gap is kept between an outer surface of the developer carrier and an inner wall of the casing downstream from an opening of the casing, upstream from a developer release portion, in a direction in which the developer carrier rotates. Multiple recesses are formed in the outer surface of the developer carrier at a pitch in a circumferential direction shorter than half a width of a magnetic flux density of the developer conveyance pole in a direction perpendicular to an axial direction of the developer carrier.

Development device, and process cartridge and image forming apparatus incorporating same

A develop roller includes a magnet roller, and a develop sleeve containing the magnet roller and comprising a plurality of depressions in an elliptic shape regularly arranged with an interval in a longitudinal direction on a surface onto which developer is attracted by a magnetic force of the magnet roller, wherein the depressions are arranged such that a longitudinal direction of the depressions is intersected with the longitudinal direction of the develop sleeve, and a downstream side of the depressions are formed to be deeper than an upstream side in a rotary direction of the develop sleeve.

Develop roller, develop unit, process cartridge, and image forming apparatus

A development device including a developer container, a developer bearer, a magnetic field generator, a developer agitator to supply the developer to the developer bearer, and a developer regulator to adjust a layer thickness of the developer carried on the developer bearer. Multiple oval recesses oblique to the axial direction of the developer bearer are formed in the outer circumferential surface of the developer bearer and arranged in a circumferential direction and the axial direction thereof. An upstream inner wall of the recess in the rotational direction of the developer bearer applies a force to the developer as the developer bearer rotates, and an angle between a long axis of the recess and the axial direction is set so that the force applied by the upstream inner wall of the recess has a component in a direction substantially identical to the developer conveyance direction of the developer agitator.

Development device, process cartridge, and image forming apparatus including same having multiple recesses formed on a developer bearer

A development roller includes a magnet roller and a rotatably supported development sleeve including inside thereof the magnet roller, the development sleeve is formed in a cylindrical shape and configured such that a shaft center of the cylindrical shape is inconsistent with a rotation axis of the development sleeve, the development sleeve includes an outer surface provided with many circular or elliptical depressions in a planar view, the depressions being regularly arranged at intervals, and a depth of the depression provided in a portion of the outer surface close to the rotation axis is larger than a depth of the depression provided in a portion of the outer surface far from the rotation axis.

Development roller, development device, process cartridge and image-forming apparatus

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 image forming device comprises a process cartridge. The process cartridge comprises a development roller. The development roller comprises a magnet roller and a developing sleeve. The magnet roller is fixed. The depressionseach having an oval shape are formed on the external surface of the developing sleeve. Both ends of the depressionswhich are adjacent with each other along the longitudinal direction of the developing sleeveare overlapped with each other and both ends of the depressionswhich are adjacent with each other along the circumferential direction of the developing sleeveare spaced with each other.

Development roller, development device, process cartridge and image forming device

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 developing roller includes a developing sleeve and a magnet roller disposed within the developing sleeve to attract developer to an outer surface of the developing sleeve by magnetic force. The outer surface of the developing sleeve has a plurality of recesses of circular or elliptic shape in plan view regularly or irregularly arranged therein so as not to overlap.

Developing roller, developing device, process cartridge, and image forming apparatus

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 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.

Electric conductive member, process cartridge and image forming apparatus

A spinal needle for performing medical treatment is inserted into the vertebral pulp, a laser probe is inserted into the spinal needle, and then laser rays are radiated onto the vertebral pulp. An air-escape tube is unitarily provided parallel to the spinal needle or a flow-passage connected with the interior of the spinal needle is provided in the vicinity of the handle portion of the spinal needle.

Growing community of inventors

Isehara, Japan

Toshio Kojima