Ricoh Company, Ltd.

Yusuke Ishizuka

Takeshi Shintani

Yasuhito Kuboshima

Hiroshi Kikuchi

Hideki Kimura

Nobuo Kuwabara

Hiroyuki Uenishi

Kenji Honjoh

Yutaka Takahashi

Yasuhiro Maehata

Hirotaka Hatta

Akira Asaoka

Daisuke Tomita

Seiichi Kogure

Akira Fujimori

Takeshi Kojima

Toshiya Sato

Takuya Akiyama

Yutaka Goto

Yuuki Aoki

Kazuhiro Shimada

Norio Kudoh

Johji Yahagi

Kenji Sugiura

Toshiya Satoh

Kazuki Yogosawa

Shinichi Kawahara

Hiroshi Mizusawa

Yuta Azeyanagi

Norio Kudo

Kento Aoki

Nobuhiro Kuwabara

An image forming apparatus includes a toner image bearer, a transfer device, a cleaner, a bias power source, and circuitry. The toner image bearer bears a toner image. The transfer device performs a transfer process. The cleaner contacts the toner image bearer to remove transfer residual toner that is subject to the transfer process and remove untransferred toner that is not subject to the transfer process. The bias power source applies one of a first bias and a second bias different from the first bias to the cleaner. The circuitry controls the bias power source to output the first bias to the cleaner in response to a start of an image forming operation to remove the untransferred toner from the toner image bearer and control the bias power source to switch an output from the first bias to the second bias.

Image forming apparatus

A powder conveying device includes a drop conveyance passage, an intersecting conveyance passage, a conveying screw, and a floating member. Powder entering from an inflow port drops in the drop conveyance passage. The intersecting conveyance passage communicates with a lower end of the drop conveyance passage and extends in an intersecting direction that intersects the drop conveyance passage. The conveying screw is disposed in the intersecting conveyance passage and rotates in a specified direction to convey the powder in the intersecting direction. The floating member is movably installed in the drop conveyance passage and floats in the drop conveyance passage to move by contact with the conveying screw. The inflow port and the floating member interfere with each other to prevent the floating member from coming out of the inflow port of the drop conveyance passage.

Powder conveying device and image forming apparatus incorporating same

An image forming apparatus includes an image bearer; a nip forming member configured to form a transfer nip between the image bearer and the nip forming member; a nip pressure changer configured to change a nip pressure of the transfer nip; a transfer bias applier configured to apply, to the transfer nip, a transfer bias in which an AC component is superimposed on a DC component; and a DC component adjuster configured to adjust the DC component in the transfer bias, according to the nip pressure that is changed by the nip pressure changer.

Transfer bias and pressure in an image forming apparatus

A cleaning device cleans a discharge wire that discharges electric charge onto a discharge target. The cleaning device moves in a longitudinal direction oldie discharge wire. The cleaning device includes a first contact portion that contacts and cleans the discharge wire and a second contact portion that contacts and cleans the discharge wire. When the first contact portion and the second contact portion clean the discharge wire, the first contact portion and the second contact portion sandwich the discharge wire in a discharge direction in which the discharge wire discharges the electric charge onto the discharge target. The discharge direction is parallel to a radial direction of the discharge wire.

Cleaning device for cleaning a discharge wire, charger, and image forming apparatus

A developing device includes a developer bearer, a developer regulator, a developer supply passage, and a stopper. The developer bearer includes a magnetic field generator and is configured to bear a developer containing toner and magnetic carriers and conveys the developer to a developing area by rotation. A stopper prevents the developer blocked by the developer regulator from moving to a surface of the developer bearer, while securing a supply path for passing the developer in the developer supply passage to the developer bearer between the stopper and an upper end of a side wall of the developer supply passage that is opposite to the developing bearer. A width of the supply path in a direction perpendicular to a direction of a rotation axis of the developer bearer is in a range of 7%-10% of a circumference of an outer diameter of the developing bearer.

Developing device with a developer regulator and a stopper

A developer conveyance device includes a downward conveyance path in which a developer falls under gravity, a transverse conveyance path communicating with a lower end of the downward conveyance path and extending in a transverse direction intersecting with the downward conveyance path, a transport screw disposed in the transverse conveyance path, and a floating member. The transport screw is configured to rotate in a predetermined direction to transport the developer in the transverse direction. The floating member is configured to contact the transport screw rotating in the predetermined direction to float in the downward conveyance path.

Developer conveyance device and image forming apparatus incorporating same

A toner conveyance device includes a downward passage, a reciprocating member disposed in the downward passage, to move in a vertical direction in which the downward passage extends, a conveyance passage communicating with a lower end of the downward passage and extending in a direction crossing the vertical direction, a conveyor to rotate in the conveyance passage around an axis extending along the conveyance passage to transport the toner, and a flexible member projecting from a bottom of the reciprocating member toward the conveyance passage. The flexible member extends in the axial direction of the conveyor and moves together with the reciprocating member. When the reciprocating member is at a lowest position, a lower end of the flexible member opposes a portion of the conveyor downstream from an upper end thereof in a rotation direction thereof.

Toner conveyance device and image forming apparatus

A device disposed opposing an image bearer includes a roller to rotate while contacting a surface of the image bearer, a rolling bearing fitted around a shaft located at an end of the roller in an axial direction of the roller, a frame to house the roller, and a bearing support removably attached to the frame. The rolling bearing includes an outer ring, an inner ring, and a rolling element disposed between the outer ring and the inner ring. The bearing support holds, from an outer-ring side, the rolling bearing interposed between the bearing support and the frame. The bearing support includes a receiving portion to contact the outer ring of the rolling bearing and bias the rolling bearing toward the frame in a direction in which the rolling bearing is interposed between the bearing support and the frame.

Device including roller, and image forming apparatus and process cartridge incorporating same

An image forming apparatus includes an image bearer to bear a toner image, a lubricant supply roller to supply lubricant to a surface of the image bearer, a rotation speed changer to change a rotation speed of the lubricant supply roller, and a controller to control the rotation speed changer to change the rotation speed of the lubricant supply roller to a target speed based on a predetermined condition. The controller is configured to control the rotation speed changer to avoid a predetermined speed range.

Image forming apparatus which controls the rotation speed of a lubricant supply roller

An image forming apparatus includes a process cartridge that includes an image bearer including a rotary shaft and rotates about the rotary shaft; a charger to charge a surface of the image bearer; and a developing device to develop an electrostatic latent image formed on the image bearer into a visible toner image. The charger includes a charging roller that rotates about a shaft together with the image bearer during image formation and electrically charges a surface of the image bearer. A surface linear speed of the charging roller is made slower than a surface linear speed of the image bearer. The image forming apparatus includes a charging roller controller that switches the rotational speed of the charging roller to a first rotational speed slower than the linear speed of the image bearer and a second rotational speed identical to the linear speed of the image bearer.

A process cartridge removably installable in an image forming apparatus includes a cartridge body including an image bearer; a cleaning unit removably attached to the cartridge body and including a lubricant supply device to lubricate the image bearer; a first contact terminal disposed in one of the cleaning unit and the cartridge body; and a second contact terminal disposed in the other of the cleaning unit and the cartridge body. The second contact terminal is disposed to contact the first contact terminal to establish electrical continuity between the cartridge body and the cleaning unit, and an end of the first contact terminal includes a sliding contact portion to slidingly contact the second contact terminal in attachment and removal of the cleaning unit to and from the cartridge body.

Process cartridge and image forming apparatus

A lubricant supplying device includes a lubricant supplier contacting an image bearer, a solid lubricant contacting the roller, a detector detecting a lubricant amount, and a controller controlling a supplying of the roller based on a detector detection. The detector outputs to the controller a first signal of a near-end state when the amount reaches a first amount, a second signal of an end state when the amount reaches a second amount smaller than the first amount, and a third signal of an absolute end state when the amount reaches a third amount smaller than the second amount. The controller temporarily stops the supplying when the second signal is output, cancels a roller temporary stopped state even when lubricant replacement is not completed after this state, stops the supplying when the third signal is output, and maintains a roller stopped state until the replacement is completed after this state.

Lubricant supplying device, process cartridge and image forming apparatus

An image forming apparatus includes a controller and multiple image forming units each of which includes an image bearer, a toner image forming device to form a toner image on the image bearer, a transfer device to transfer the toner image from the image bearer onto a transfer medium, a cleaning device to remove toner from a surface of the image bearer, a waste-toner tube through which toner removed by the cleaning device is transported, and a toner conveying member to transport toner by rotation and disposed inside the waste-toner tube. The controller changes a rotation speed of the toner conveying member for each of the multiple image forming units according to toner type including a first toner and a second toner having poorer flow properties than the first toner, and at least one image forming units uses the second toner and the rest use the first toner.

An image forming apparatus includes a first image forming device, a plurality of second image forming devices, a first bias voltage supply device, and a second bias voltage supply device. The first image forming device and the second image forming device form a toner image. The first bias voltage supply device applies a bias voltage to a first component of the first image forming device. The second bias voltage supply device applies a bias voltage to a second component of each of the plurality of second image forming devices.

Image forming apparatus including first and second bias voltage supply devices

A cleaning unit, which is included in a process cartridge or an image forming apparatus, includes a brush rotary body to remove toner, a toner collecting rotary body to collect the toner, a toner collecting blade to scrape the toner, and a cleaning blade to scrape the toner falling from the brush rotary body. The image carrier, the brush rotary body, and the toner collecting rotary body rotate in the same direction. The cleaning blade, the brush rotary body, and the toner collecting rotary body are located to cause a tangential line passing through a contact area of the brush rotary body and the toner collecting rotary body on an outer peripheral circle around a shaft of the brush rotary body to have an intersection point intersecting a non-contact surface of the cleaning blade disposed opposite to a contact portion of the cleaning blade with the image carrier.

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Kanagawa, Japan

Yusuke Ishizuka