Ricoh Company, Ltd.

Hiroki Nakamatsu

Kenji Sugiura

Hidetoshi Yano

Naomi Sugimoto

Seiichi Kogure

Osamu Naruse

Naohiro Kumagai

Kazuki Yogosawa

Katsuhito Haruno

Takahiro Suzuki

Shinya Tanaka

Hirokazu Ishii

Junpei Fujita

Yoshiki Hozumi

Yuuji Wada

Masanari Fujita

Masaharu Furuya

Atsushi Nagata

Katsuya Kawagoe

Naoto Kochi

Masakazu Imai

Keigo Nakamura

Takehide Mizutani

A belt device includes a belt wound around a plurality of rollers, one of the plurality of rollers, and a belt contact member disposed on the one of the plurality of rollers. The belt rotates along with the plurality of rollers. The belt contact member faces an edge of the belt in an axial direction of the one of the plurality of rollers and includes a flat portion and a separation portion. The flat portion forms a plane perpendicular to the axial direction of the one of the plurality of rollers. The separation portion is disposed outboard of the flat portion in a radial direction of the one of the plurality of rollers and has a surface located farther from the edge of the belt than the flat portion in the axial direction of the one of the plurality of rollers.

Belt device, belt regulator, roller unit, and image forming apparatus

A belt control device includes a plurality of rollers, a belt wound around the plurality of rollers and configured to rotate along with the plurality of rollers, a belt contact member that the belt contacts when the belt moves in an axial direction of the plurality of rollers, and a shaft displacement member movable in the axial direction and including an inclined face inclined with respect to a surface of the belt to control movement of the belt in the axial direction. The belt, the belt contact member, and the shaft displacement member are configured to make a frictional force between an edge of the belt and the belt contact member greater than a frictional force between the belt contact member and the shaft displacement member.

Belt control device and image forming apparatus incorporating same

An improved image forming apparatus includes an image bearer, a nip forming member, a transfer power source, and a controller. The controller switches a transfer mode between a first mode to transfer the toner image onto a first type sheet having a surface smoothness higher than a surface smoothness of a second type sheet and a second mode to transfer the toner image onto the second type sheet. The controller controls the transfer power source to output the transfer bias having an opposite-peak duty of greater than or equal to 50% that is a duty on the side of the opposite-peak value in the first mode. The controller controls the transfer power source to output the transfer bias having an opposite-peak duty of less than 50%, which is different from the opposite-peak duty of the first mode, in the second mode.

Image forming apparatus and image forming method

An image forming apparatus includes an image bearer to bear a toner image, a nip forming member contacting the image bearer to form a transfer nip, and a transfer power source. The transfer bias has a transfer peak value to electrostatically move toner from the image bearer to the recording sheet and an opposite-peak value to electrostatically move less toner from the image bearer to the recording sheet than the transfer peak value. An opposite-peak duty of the transfer bias is less than 50%. The opposite-peak duty is tr/T&#xd7;100% where T is one cycle of the transfer bias and tr is a time period during which the transfer bias is on a side of the opposite-peak value relative to an offset voltage of the transfer bias in the one cycle T.

Image forming apparatus and image forming method for controlling a secondary transfer bias according to recording sheet type

An image forming apparatus includes a housing and a transfer unit. The transfer unit detachably attachable relative to the housing includes a drive roller, a driven roller disposed opposite the drive roller, a belt formed into a loop and entrained around the drive roller and the driven roller, a frame to support the shaft of the drive roller, and a support member to movably support the shaft of the driven roller to be parallel to an axial direction of the drive roller and movable in a first direction different from the axial direction. A positioning member disposed in the housing holds the shaft of the drive roller parallel, and a restriction member restricts movement of the driven roller in the first direction to keep the shaft of the driven roller parallel to the shaft of the drive roller as the transfer unit is mounted in the image forming apparatus.

Transfer belt device and image forming apparatus including the same

The image forming apparatus includes an image bearing member bearing a toner image; a driving roller and a tension roller movable in such a direction that the interval between the rollers changes; a transfer belt stretched by the rollers to feed a receiving material so that the toner image on the image bearing member is transferred onto the receiving material or to directly receive the toner image from the image bearing member; a detector opposed to the tension roller with the belt therebetween to optically detect a mark on the belt, wherein the detector is movably supported while biased toward the tension roller, and the moving direction of the tension roller is substantially the same as an optical axis of light emitted by the detector; and a regulator to regulate movement of the tension roller and the detector in a direction perpendicular to the moving direction of the tension roller.

Image forming apparatus having a movably supported transfer belt detector

A transfer device includes a rotatable intermediate transfer belt wound around and stretched between a pair of rollers, facing a plurality of image bearing members bearing toner images, a plurality of transfer members facing the image bearing members through the intermediate transfer member, to transfer overlappingly the toner images onto the intermediate transfer member forming a composite toner image, a lubricant applicator disposed upstream from the image bearing members in a direction of rotation of the intermediate transfer belt and on the same plane as the image bearing members, to apply a lubricant on the intermediate transfer member, an opposing member disposed opposite the lubricant applicator, to contact the lubricant applicator through the intermediate transfer member, and a pressure member disposed upstream from the image bearing members and downstream from the lubricant applicator in the direction of rotation of the intermediate transfer belt, to press against the intermediate transfer member.

Transfer device and image forming apparatus including same

A cleaning unit that can remove particles of residual toner remaining on an image carrier after transfer and be incorporated in a process cartridge removably installable to an image forming apparatus, includes a brush roller disposed in contact with the image carrier to remove the residual toner remaining on the image carrier from the image carrier, and a polarity control member disposed in contact with the image carrier to control charge polarities of the residual toner remaining on the image carrier before the residual toner is removed by the brush roller. The polarity control member includes a first surface where the polarity control member contacts the image carrier, a second surface where the polarity control member does not contact the image carrier, and a conductive filler that is not exposed on the first surface that contacts the image carrier.

Cleaning unit for an electrophotographic image forming apparatus having a polarity control member

A cleaning devicefor removing a toner remaining on an image bearing memberA after transfer, including: a polarity control memberconfigured to unify polarities of the remaining toner on the image bearing memberA, a cleaning memberconfigured to remove the remaining toner having a polarity unified by the polarity control member, a collecting memberconfigured to collect the remaining toner transferred to the cleaning member, a bladeconfigured to remove the remaining toner from the collecting member, and a brush rollerconfigured to sweep the remaining toner on the image bearing memberA and inject charge, disposed upstream of the polarity control memberin the traveling direction of the image bearing memberA.

Cleaning device and image forming apparatus

A polarity controlling device for controlling polarity of residual material on an image bearing member, including a blade, to which a first voltage is applied and which has a contact edge contacted with the surface of the image bearing member to charge the residual material, wherein the contact edge is covered with a resin layer including an electroconductive material. A cleaner including the polarity controlling device; a brush contacting the image bearing member to electrostatically collect the charged residual material utilizing potential difference; a collection member contacting the brush to collect the residual material; and a cleaning blade contacting the collection member to scrape the residual material therefrom. An image forming apparatus including an electrostatic image bearing member; a developing device developing the electrostatic image using a developer including a toner to form a toner image; a transfer device transferring the toner image onto a receiving material; and the cleaner.

Polarity controlling device, and cleaner and image forming apparatus using the polarity controlling device

A cleaning device including a conductive member configured to charge powder remaining on a member to be cleaned so as to have a single polarity and configured to scrape off at least part of the powder, and disposed to contact with the member to be cleaned; a cleaning member configured to electrically adsorb the powder present on the member to be cleaned, disposed to contact with the member to be cleaned and located downstream of the conductive member in a direction in which the powder is conveyed thereon; a first recovering member configured to electrically adsorb the powder present on the cleaning member and disposed to contact with the cleaning member; and a second recovering member configured to scrape off the powder from the first recovering member and disposed to contact with the first recovering member, wherein the conductive member is constant-current controlled.

Cleaning device, image forming apparatus, and process cartridge

A cleaning unit, providable to an image carrier unit or an image forming apparatus, includes a cleaning member disposed in contact with a target member to electrically remove residual toner from the target member, an elastic blade disposed in contact with the target member upstream from the cleaning member, a blade supporting member, a blade power source, and a conductive member that is more conductive than the elastic blade, and electrically connects the blade supporting member and the elastic blade. The conductive member is disposed so that an edge part of the conductive member is closer to where the elastic blade contacts the target member than an edge part of the blade supporting member.

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Kanagawa, Japan

Hiroki Nakamatsu