Ricoh Company, Ltd.

Minoru Toyoda

Tomohiko Fujii

Yutaka Naitoh

Hitoshi Fujiwara

Tomoya Adachi

Shigeo Nanno

Yasuharu Kawarasaki

Yoshiharu Takahashi

Tamotsu Ikeda

Daisuke Inoue

Masahiro Samei

Yoshihiro Fukuhata

Yasuhide Matsuno

Kenji Nakamura

Naoki Nakatake

Hirobumi Ooyoshi

Kazuki Matsumoto

Tetsu Morino

Takeshi Yamashita

Tomohiro Kubota

Yasuhiro Fujiwara

Osamu Saito

Emi Kita

Masanari Fujita

Atsushi Takehara

Mitsutoshi Kichise

Kentaro Nodera

Toshiki Hayashi

Katsumi Kumada

Keiji Kunimi

Yuuji Ishikura

Takahiro Yoshimi

Isamu Kubo

Katsumasa Mikami

Tatsuya Ohhira

Yuichiro Suzuki

Kyoko Abe

Takahiro Sanada

Rumi Miyazaki

Kouichi Oomori

Yumi Inoue

Yoshitaka Omori

A developing device includes a developer bearer, a first conveying screw conveying developer from one end to another end of a first conveyance path in a first direction, a second conveying screw conveying the developer in a direction opposite to the first direction in a second conveyance path, and a partition having a first communication port communicating the one end of the first conveyance path and the second conveyance path. A shaft diameter of the first conveying screw from one end to a position away from the first communication port by a first predetermined distance is smaller than a shaft diameter of another portion of the first conveying screw. A shaft diameter of the second conveying screw from one end to a position away from the first communication port by a second predetermined distance is larger than a shaft diameter of another portion of the second conveying screw.

Developing device, process cartridge, and image forming apparatus

A powder collection container that is attachable to and detachable from a mount part of an apparatus and stores powder includes a plurality of walls that form a storage space to store the powder. The plurality of walls include a first wall that faces the mount part of the apparatus and a second wall that does not to face the mount part of the apparatus. A thickness of the first wall is smaller than a thickness of the second wall.

Apparatus including an extior cover to open and close a powder collection container

A powder storage container is provided. The powder storage container includes a container body, a discharge port, a conveyer, a stirrer, a return port, and a partition wall. The container body is configured to contain powder. The powder contained in the container body is dischargeable through the discharge port. The conveyer is configured to convey the powder to the discharge port. The stirrer is configured to stir the powder contained in the container body by rotating. The return port is disposed outside a rotational locus of the stirrer in a radial direction, and the powder conveyed by the conveyer is returnable through the return port toward the stirrer. The partition wall is disposed between the stirrer and the return port with at least a part of the partition wall positioned above the return port.

Powder storage container and image forming apparatus

A developing device is provided which includes: a developing roller in contact with or facing an image bearer; a supply roller to supply toner to the developing roller; a casing; a first conveyer disposed within the casing and above the supply roller to supply toner stored in the developing device to the supply roller, while forming a first conveyance path; a second conveyer disposed within the casing with an upper end thereof positioned below that of the first conveyer, while forming a second conveyance path forming a toner circulation path together with the first conveyance path; a partition wall separating the first conveyance path and the second conveyance path in a longitudinal direction within a range excluding both longitudinal end portions; and a toner supply port, at a ceiling of the casing above the second conveyance path, through which toner is supplied to an inside of the developing device.

A fixing device includes a drive roller, a driven roller driven to rotate by the drive roller, and a braking force applicator. The driven roller presses against the drive roller to form an area of contact between the drive roller and the driven roller, through which a recording medium bearing a toner image passes. The braking force applicator applies a braking force to the driven roller to generate a shear force between the drive roller and the driven roller. The shear force acting between the drive roller and the driven roller when the drive roller and the driven roller rotate is in a range of from 15N to 25N.

Fixing device, fixing method, and image forming apparatus

A fixing device includes a first rotary body, a second rotary body to contact the first rotary body, and a plain bearing that supports the first rotary body or the second rotary body. One rotary body of the first rotary body and the second rotary body has an outer diameter increasing, while the other rotary body has an outer diameter decreasing, in a curved line from an axial center portion to axial end portions of the first rotary body and the second rotary body at least between the first rotary body and the second rotary body. A recording medium passes between the first rotary body and the second rotary body with a circumferential component of a shear force generated between the first rotary body and the second rotary body by use of the plain bearing being in a range of from 15N to 25N.

Fixing device and image forming apparatus incorporating same

A fixing device includes a heat conductor disposed opposite an inner circumferential surface of an endless belt to heat the endless belt. A nip formation pad is disposed opposite the inner circumferential surface of the endless belt and presses the endless belt against a pressing rotary body to form a fixing nip between the endless belt and the pressing rotary body through which a recording medium bearing a toner image is conveyed. A support is disposed opposite an inner circumferential surface of the heat conductor and contacts an abutment face of the nip formation pad to support the nip formation pad against pressure from the pressing rotary body. A heat insulator is interposed between the heater and the nip formation pad and the support to shield the nip formation pad and the support from the heater.

Fixing device and image forming apparatus

An image forming apparatus includes an image forming device to form a cleaning toner image in a cleaning region on a cleaning sheet and a check toner image in a check region on the cleaning sheet. The image forming apparatus further includes a fixing device including a first rotator and a heater to heat the first rotator to a cleaning temperature that is lower than a fixing temperature to which the first rotator is heated in a print job and higher than a cold offset temperature at which toner adheres to the first rotator by cold offset. Each of the cleaning region and the check region has a length greater than a circumferential length of the first rotator. The cleaning region and the check region are disposed at a leading section and a trailing section of the cleaning sheet in a cleaning sheet conveyance direction, respectively.

Image forming apparatus and image forming method including forming a cleaning toner image

A fixing unit includes an endless belt accommodating a heat source inside a loop formed by the endless belt, a rotary pressing member rotating in contact with the endless belt in a pressure contact section, and a heat transfer member secured to a side plate within the loop of the endless belt to support and heat the endless belt with heat conducted from the heat source. The heat transfer member has an opening opposite the rotary pressing member. A securing member is disposed in the opening of the heat transfer member in pressure contact with the rotary pressing member via the endless belt. The heat transfer member and the securing member collectively include a pair of latching parts to firmly connect the heat transfer member and the securing member with each other when one of the latching parts is fitted to the other one of the latching parts.

Fixing device and image forming apparatus and method of assembling the fixing device

A process unit includes a rotatable image bearer to bear a toner image on a surface thereof; a developer bearer to supply developer to the image bearer and including a first range, a second range different in property from the first range and adjacent to the first range on an outer side in an axial direction via a first boundary, and a second boundary on an outer side of the first boundary in the axial direction; a cleaning member to remove residual developer from the image bearer; and an abutment part disposed to contact the surface of the image bearer to remove a foreign substance from the image bearer. The abutment part is disposed astride at least one of a first position on the image bearer corresponding to the first boundary, and a second position on the image bearer corresponding to the second boundary.

Process unit and image forming apparatus incorporating same

A fixing device fixes a toner image on a recording medium transported to a fixing nip by applying pressure and heat to the recording medium. The fixing device includes an endless belt formed into a loop with both ends bonded together, the belt accommodating a heat source inside thereof, a pressing roller rotating in contact with the endless belt forming the fixing nip between the endless belt and the pressing roller, and a fixed member provided inside a loop of the endless belt to press the endless belt against a pressing roller. A reinforcing member is bonded to the fixed member inside the loop of the endless belt to reinforce the fixed member. A reflector is provided to reflect light emitted from the heat source toward the inner circumferential surface of the endless belt. The reflector is held on the reinforcing member by either plastically or elastically deforming by itself.

Fixing device, image forming apparatus with same, and method of assembling fixing device

A fixing device includes a nip formation pad disposed opposite an inner circumferential surface of an endless belt and a pressing rotary body pressed against the nip formation pad via the endless belt to form a fixing nip between the endless belt and the pressing rotary body, through which a recording medium is conveyed. The pressing rotary body has a diameter increasing from a center to each lateral end in an axial direction thereof. The nip formation pad includes a projection disposed downstream from a rotation axis of the pressing rotary body in a recording medium conveyance direction. The projection projects toward the pressing rotary body in an amount increasing from each lateral end to a center in a longitudinal direction of the nip formation pad parallel to the axial direction of the pressing rotary body.

A mechanism for electrifying a rotator that is used in an image forming apparatus includes a cloth-like or sheet-like conductive member, wherein part of the conductive member comes into contact with an object to be electrified and the other part of the conductive member comes into surface contact with any one contact member of the rotator, a rotating shaft that rotates together with the rotator, and a shaft where the rotator is rotatably supported, so that the object to be electrified and the contact member are electrically connected to each other through the conductive member.

Mechanism for electrifying, method of electrifying, and conductive member

A fixing unit includes an endless belt unit accommodating a heat source, a pressure roller to rotate in contact with the fixing belt unit forming a pressure border therebetween, and a heat transfer member heated by the heat source to heat the fixing belt unit. The heat transfer member is secured inside an inner circumferential surface of the fixing belt unit and supports the fixing belt unit. A fixed member is secured inside the inner circumferential surface of the fixing belt unit and is pressed against the pressure roller via the fixing belt unit. The heat transfer member has at least one convex portion partially formed in an outer circumferential surface of the heat transfer member in a rotational direction of the fixing belt unit and a longitudinal direction of the heat transfer member to narrow a gap formed between the heat transfer member and the fixing belt unit.

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Hyogo, Japan

Minoru Toyoda