Ricoh Company, Ltd.

Osamu Ichihashi

Junpei Fujita

Kenji Sengoku

Ryuuichi Mimbu

Yasufumi Takahashi

Tsutomu Kato

Yuji Kato

Masakazu Imai

Takehide Mizutani

Katsuhito Haruno

Shinya Tanaka

Hirokazu Ishii

Naoto Kochi

Atsushi Nakamoto

Katsuya Kawagoe

Takahiro Konishi

Ryuichi Minbe

Naoki Iwaya

Kazuosa Kuma

Ryo Hasegawa

Masaharu Furuya

Atsushi Nagata

Tatsuya Ohsugi

Haruki Nagata

Ryuichi Minbu

A belt device includes a plurality of rollers, a belt stretched and supported around the plurality of rollers, a roller shaft included in one of the plurality of rollers and configured to rotate along with the one of the plurality of rollers, a shaft inclination member slidably supported by the roller shaft, a cleaning member opposed to the one of the plurality of rollers via the belt, a bearing configured to rotatably support the roller shaft, and a support configured to rotatably support the bearing. The shaft inclination member is configured to incline the roller shaft in conjunction with movement in which the belt moves in a width direction of the belt device. The cleaning member is configured to clean the belt. The bearing is configured to stationarily support the cleaning member.

Belt device and image forming apparatus incorporating same

A roller member includes a cored bar, an elastic layer, and a non-conductive member. The elastic layer is disposed on an outer circumferential face of the cored bar. The cored bar has a projecting portion projecting beyond a range in which the elastic layer is disposed, toward an axial end of the cored bar. The non-conductive member is made of a non-conductive material. The non-conductive member is disposed on the projecting portion. The non-conductive member bites into an end face of an axial end of the elastic layer.

Roller member and image forming apparatus including the roller member

An image forming apparatus includes a developing device, an image bearer, a transfer rotator, a blade contacting a surface of the transfer rotator, and a controller to control the developing device, the image bearer, and the transfer rotator. A first toner pattern image is formed on the image bearer, transferred onto the transfer rotator, and passed past the blade at least twice together with rotation of the transfer rotator in at start-up of the image forming apparatus. A second toner pattern image is formed on the image bearer after the start-up and during passage of a non-image area in which toner images are not formed. A range of the first toner pattern image is wider than a range of the second toner pattern image in a width direction perpendicular to a direction of travel of the image bearer.

Transfer rotator and image forming apparatus comprising the same

A transfer device includes an image bearer, a rotatable body, a solid lubricant assembly, and a guide. An image bearer bears an image. The rotatable body forms a transfer nip with the image bearer to rotate in contact with a recording medium. An image on the image bearer is transferred onto the recording medium at the transfer nip. The solid lubricant assembly includes a solid lubricant and extends in a longitudinal direction of the rotatable body. The solid lubricant assembly applies a solid lubricant to at least one of the rotatable body and the image bearer. The guide guides the recording medium and positions the solid lubricant assembly.

Transfer device and image forming apparatus incorporating same

A roller member includes a cored bar, an elastic layer, a first high resistance member, and a second high resistance member. The elastic layer is disposed on an outer circumferential face of the cored bar. The cored bar has a projecting portion projecting beyond a range in which the elastic layer is disposed, toward an axial end of the cored bar. The first high resistance member is made of a high-resistance material having a higher electrical resistance than an electrical resistance of the cored bar. The first high resistance member is fitted to the projecting portion. The second high resistance member is made of a high-resistance material having a higher electrical resistance than an electrical resistance of the cored bar. The second high resistance member fills a space between the first high resistance member and the elastic layer.

Roller member including a first and second high resistance member and image forming apparatus including the roller member

A transfer device includes an image bearer and a transfer rotator. The transfer device further includes an adjuster including a rotatable cam and an opposed member opposed to the cam. The cam alternately contacts and separates the transfer rotator against and from the image bearer, having a continuous sloped surface with a plurality of positions, each position to contact the opposed member to obtain a different amount of separation between the image bearer and the transfer rotator. The transfer device further includes a controller to control the adjuster to adjust the amount of separation between the transfer rotator and the image bearer according to thickness or type of the recording medium when the recording medium starts to enter the transfer nip.

An image forming apparatus includes an image bearer, an image forming device, a transfer member, and a contact-and-separation device. The contact-and-separation device starts a contact operation to move the transfer member to contact the image bearer according to an entry of a recording medium into a transfer nip. The thinner the recording medium, the faster a contacting speed at which the transfer member moves to contact the image bearer. The thicker the recording medium, the slower the contacting speed.

Image forming apparatus

An image forming apparatus includes an image carrier that carries a toner image; a transfer member that forms a transfer nip between the transfer member and the image carrier; and a power supply capable of outputting a superimposed transfer bias in which an alternating current component is superimposed onto a direct current component. The toner image on the image carrier is transferred onto a recording medium in the transfer nip by the superimposed transfer bias or a direct current bias consisting of the direct current component output by the power supply. The apparatus also includes a controller that controls the power supply so that an output target value of the direct current component when the direct current component rises up is larger than an output target value of the direct current component when the toner image is transferred onto the recording medium.

A transfer device includes a moving device to move a contact surface of an opposing member toward and away from an image bearing surface of an image bearing member. The moving device includes a cam and a cam driving device to rotate the cam. When the cam is at a first position, the image bearing surface and the contact surface are separated. When the cam is at a second position, the image bearing surface and the contact surface contact each other. After a recording medium enters a transfer nip between the image bearing surface and the contact surface, the cam is at the second position, and when the recording medium exits the transfer nip a timing at which the cam starts to rotate from the second position to the first position changes depending on a thickness of the recording medium, to reduce pressure in the transfer nip.

Transfer device and image forming apparatus including same

A transfer device includes a transfer member and a bias applicator. The transfer member contacts a surface, on which a toner image is borne, of an image bearing body, to form a transfer nip. The bias applicator applies a DC voltage and an AC voltage as transfer bias to transfer the toner image on the image bearing body to a recording sheet in the transfer nip. The bias applicator applies a DC voltage having a same polarity as the DC voltage of the transfer bias and an AC voltage having an amplitude smaller than the AC voltage of the transfer bias or applies the DC voltage having the same polarity as the DC voltage of the transfer bias without applying an AC voltage, when an inter-sheet area that exists on the image bearing body passes through the transfer nip during a continuous image formation period.

A transfer device includes an image carrier, a transfer roller, and a moving unit. The moving unit moves the transfer roller between a nip formation state in which the transfer roller forms a transfer nipping portion in contact with the image carrier and a separated state in which the transfer roller is separated from the image carrier. In a contact operation of bringing the transfer roller into contact with the image carrier via the recording medium, the moving unit moves the transfer roller toward the image carrier at a moving velocity slower than that in a pressing operation of generating a predetermined nipping pressure by further moving the transfer roller toward the image carrier after the contact operation. The moving unit causes the recording medium to enter the transfer nipping portion in the contact operation.

An image forming apparatus includes multiple image bearing members, toner image forming devices, and a transfer unit. The transfer unit includes an intermediate transfer belt entrained about a plurality of rollers and onto which toner images are transferred from the image bearing members, a reference member to position the transfer unit in place, a frame to hold the plurality of rollers a certain distance from the reference member, and a moving device including a holding member to hold movably one of the rollers relative to the frame to change the position of the roller between a multiple color mode for forming a multiple color image and a single color mode for forming a single color image so that the intermediate transfer belt contacts and separates from the image bearing member. As the holding member contacts the reference member, the intermediate transfer belt contacts the image bearing members.

Image forming apparatus including a holding member to hold a roller relative to a frame

An image forming apparatus includes an image forming unit; an intermediate transfer member; a secondary transfer member to form a secondary transfer nip with the intermediate transfer member and the secondary transfer member; a biasing mechanism to bias the secondary transfer member toward the intermediate transfer member; a cam member rotatable between a first position, at which a predetermined space is formed in the secondary transfer nip, and a second position, at which the secondary transfer member and the intermediate transfer member contact each other; and a contact-separation controller configured to put the cam member in the first position before entry of the recording medium into the secondary transfer nip, rotate the cam member toward the second position when the recording medium enters the secondary transfer nip, and change a start timing of rotation of the cam member in accordance with a thickness of the recording medium.

Image forming apparatus including a cam member to separate a transfer member

An image forming apparatus includes an image carrier, a transfer member, a power supply, and a control device that controls the power supply to output a DC-AC superimposed bias or a DC bias to transfer a toner image on the image carrier onto a recording medium. The control device controls the power supply to alternately output a first bias being a DC component the same in polarity as the DC bias and a second bias being a DC component opposite in polarity to the DC bias to clean the transfer member when image formation is not taking place. The first bias is output with two target output values including a first value and a second value lower than the first value. The second bias is output with one target output value. An output time of the second bias is longer than an output time of the first bias.

An image forming apparatus includes: a belt unit that includes a belt-shaped image carrier stretched around and driven to rotate by a plurality of rollers; a belt tensioning unit that includes a tensioning member that is brought into contact with an image carrying surface of the belt-shaped image carrier and applies tension to the belt-shaped image carrier; and a cleaning unit that includes a cleaning member that is brought into contact with the image carrying surface of the belt-shaped image carrier and cleans the image carrying surface. The cleaning unit is supported by the belt tensioning unit in an attachable and detachable manner.

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Kanagawa, Japan

Osamu Ichihashi