Ricoh Company, Ltd.

Motoyoshi Yamano

Kohichi Utsunomiya

Yutaka Ikebuchi

Arinobu Yoshiura

Hideo Nagafuji

Yuji Arai

Shohei Saito

Tetsuo Tokuda

Qifeng Cui

Satoshi Ueno

Fumihiro Hirose

Naoto Suzuki

Takashi Sakamaki

Kiho Sai

Takuya Seshita

Keitaro Shoji

Kenji Ishii

Akira Suzuki

Hiroshi Ono

Takahiro Imada

Hiromasa Takagi

Hajime Gotoh

Jun Okamoto

Yoshikuni Sasaki

Ryohhei Sugiyama

Hironori Yamaoka

Shinji Kato

Kazuya Saito

Takayuki Seki

Shuji Hirai

Yasunori Ishigaya

Ryota Yamashina

Shinichi Namekata

Takumi Waida

Shingo Kuboki

Terumichi Ochi

Daisuke Sawada

Yuuki Nobuoka

Takahiro Kikuchi

Yuichi Harashima

Satoshi Endoh

Yohichi Tsukamoto

An image forming apparatus includes a fixing rotator rotatable in a predetermined direction of rotation, over which a recording medium is conveyed, and a heater to heat the fixing rotator. A temperature detector detects a temperature of the fixing rotator. A controller performs a primary productivity control to define a primary productivity rate of printing per unit time based on the temperature of the fixing rotator that is detected by the temperature detector. The controller calculates an amount of power suppliable to the heater and performs a secondary productivity control simultaneously with and separately from the primary productivity control. The secondary productivity control defines a secondary productivity rate of printing per unit time based on the amount of power suppliable to the heater. The controller selects one of the primary productivity rate and the secondary productivity rate whichever is lower as a productivity rate of the image forming apparatus.

Image forming apparatus and image forming method with temperature and power-based productivity rate selection

A fixing device includes a fixing rotator to fix an image on a recording medium, a pressure rotator to press against an outer circumferential surface of the fixing rotator, a nip formation pad disposed inside the fixing rotator and opposite the pressure rotator to form an area of contact between the fixing rotator and the pressure rotator, and a slide member disposed between the fixing rotator and the nip formation pad and applied with lubricant to slide the fixing rotator in a sliding direction. The slide member includes first strands disposed parallel to the sliding direction and second strands disposed perpendicular to the sliding direction and interwoven with the first strands. The first strands are woven over the second strands longer than the second strands woven over the first strands.

Fixing device, image forming apparatus, and slide member

A fixing device includes a fixing rotator rotatable in a predetermined direction of rotation and a heater that heats the fixing rotator. A nip formation pad is disposed opposite an inner circumferential surface of the fixing rotator. A pressure rotator presses against the nip formation pad via the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator. A low-friction member is sandwiched between the nip formation pad and the fixing rotator and bears a lubricant that flows in a flow direction. A thermal absorber is mounted on the inner circumferential surface of the fixing rotator. At least one irregular portion, mounted on the thermal absorber, blocks the lubricant flowing in the flow direction.

Fixing device and image forming apparatus

A fixing device includes a fixing rotator that is endless and rotatable in a rotation direction and a heater to heat the fixing rotator. A pressure rotator contacts an outer circumferential surface of the fixing rotator. A nip formation pad presses against the pressure rotator via the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator. The nip formation pad includes an upstream portion disposed upstream from the fixing nip in the rotation direction of the fixing rotator. A recess is disposed in the upstream portion of the nip formation pad. A friction reducer is sandwiched between the nip formation pad and the fixing rotator and bears a lubricant.

Fixing device and image forming apparatus including a friction reducer including a lubricant

A fixing device includes a heater, a fixing rotator, a pressure rotator to press against the fixing rotator to form a fixing nip between the fixing rotator and the pressure rotator, through which a recording medium is conveyed, a moving device to move the pressure rotator in directions in which the pressure rotator comes into contact with and separates from the fixing rotator, a thermal expansion amount predictor to predict an amount of thermal expansion of the fixing rotator while the recording medium is conveyed, and a nip width adjuster to control a moving distance of the pressure rotator moved by the moving device toward the fixing rotator, depending on the amount of thermal expansion of the fixing rotator predicted by the thermal expansion amount predictor, so as to adjust a width of the fixing nip to maintain a substantially constant width of the fixing nip.

Fixing device, image forming apparatus, and method of controlling fixing device

A fixing device includes a fixing rotator, a heat source, a controller, a pressure rotator, and a nip formation pad. The controller controls the heat source such that a temperature of the fixing rotator is equal to a preset fixing temperature. The nip formation pad abuts the pressure rotator via the fixing rotator and forms a nip between the fixing rotator and the pressure rotator. When a print time of a previous job is longer than a prescribed time A and a next job is started within a prescribed time B after an end of the previous job, the controller corrects the preset fixing temperature during a time from a start of the next job to an entry of a print sheet into the nip and during a time from the entry of the print sheet into the nip to a lapse of a prescribed time C after the entry.

Fixing device and image forming apparatus incorporating fixing device

A paper conveying device includes a conveying guide, a bearing, a conveying-guide facing surface, and a separation restrictor. The conveying guide includes a conveyance surface for conveying paper and a pivot shaft and is swingable about the pivot shaft. The bearing includes a support surface facing at least an upper semiperimeter of the pivot shaft. The conveying-guide facing surface is provided to face an end of the conveying guide when the conveying guide swings. The end is opposite to the conveyance surface. The separation restrictor is provided to the conveying guide to restrict separation of the pivot shaft from the bearing at least in a given swing range of the conveying guide by contacting the conveying-guide facing surface.

Paper conveying device and image forming device

A fixing device includes: a fixing member that is rotatable and in an endless shape; a heat source that heats the fixing member; a nip forming member that is arranged inside the fixing member; and a pressurizing member that is pressurized to be in contact with the nip forming member through the fixing member, to form a fixing nip. The fixing device fixes an unfixed image on a recording medium by passing the recording medium that carries the unfixed image through the fixing nip. The nip forming member includes a base layer, and a high thermal-conductive layer that is arranged on a surface layer of the base layer on a fixing nip side, and that has higher thermal conductivity than the base layer, and in the high thermal-conductive layer, a low thermal-conductive portion is arranged near an end portion in an axial direction of the fixing member.

Fixing device with nip forming member having a high thermal-conductive layer with a low thermal conductive portion

A fixing device includes a nip formation pad to form a fixing nip between a first fixing rotator and a second fixing rotator, through which a recording medium bearing a toner image is conveyed. The nip formation pad includes a first planar face, a second planar face disposed downstream from the first planar face in a recording medium conveyance direction and being parallel to the first planar face, and a joint face bridging the first planar face and the second planar face. The joint face includes a first curved portion adjoining the first planar face and having a first curvature in a first direction in which a circumferential face of the second fixing rotator is curved and a second curved portion adjoining the second planar face and having a second curvature in a second direction opposite the first direction.

A fixing device includes an endless belt rotatable in a predetermined direction of rotation and a nip formation pad disposed opposite an inner circumferential surface of the endless belt. A slide sheet is sandwiched between the nip formation pad and the endless belt and is a twill fabric containing a lubricant. The slide sheet includes a first sheet contacting the nip formation pad and including a first gutter defined by a first twill line in a first direction angled relative to the direction of rotation of the endless belt and a second sheet layered on the first sheet and contacting the endless belt. The second sheet includes a second gutter defined by a second twill line in a second direction angled relative to the direction of rotation of the endless belt.

Fixing device and image forming apparatus comprising a multilayered twill fabric slide sheet

A device includes a fixing belt, a holder that holds the fixing belt, a pressing member that comes in contact with the fixing belt, a nip-forming-member arranged inside the fixing belt, that forms a nip by coming in contact with the pressing member, a supporting member that supports the nip-forming-member, a side plate to which the nip-forming-member and the supporting member are fixed, and a pressing mechanism that presses a pressing roller to the nip-forming-member via the fixing belt. The supporting member includes at least two plates. The two plates are separated from each other near a contact portion where the plates come in contact with the nip-forming-member. At least a part of each of the plates is a flat surface parallel to a direction of a load applied by the pressing mechanism. Portions of the two plates on a side distant from the contact portion are joined together.

Fixing device and image forming apparatus including a nip-forming-member supported by at least two plates joined together

A fixing device includes: a fixing member; an opposing member that provides a fixing nip with the fixing member; a heating unit that heats the fixing member; a heating area changing member that moves to change a heating area of the fixing member heated by the heating unit; and a position detection sensor that detects a position of the heating area changing member. The fixing device controls a stop position of the heating area changing member based on detection by the position detection sensor. The single position detection sensor detects the position of the heating area changing member both when the heating area changing member is moving from a preset reference position to an arbitrary position and when the heating area changing member is moving back from an arbitrary position to the reference position.

Fixing device of an image forming apparatus that utilizes edge detections for heat shield positional determinations

A fixing device includes an endless fixing belt: a fixing belt holding member; a pressure member that makes a contact with the circumference of the fixing belt; a nip forming member that is disposed inside the fixing belt and forms a nip between the nip forming member and the pressure member; a nip supporting member that is made of a sheet metal; a side plate that supports the fixing belt holding member and the nip supporting member; and a pressure mechanism that presses the pressure member against the nip forming member with the fixing belt between the pressure member and the nip forming member. Both end surfaces of the nip supporting member are shear surfaces and one of the shear surfaces makes a contact with the nip forming member and the other shear surface is supported by the side plate.

Fixing device and image forming apparatus which utilizes a nip supporting member to support a nip forming member

An image forming apparatus includes paper trays to contain and feed a recording sheet on which a toner image is transferred; status sensors to detect a storage status of the recording sheet contained in the paper trays; a sheet sensor to detect a smoothness of the recording sheet; a memory to store detection values of the smoothness detected by the sheet sensor; a fixing device to heat and press the toner image transferred onto the recording sheet and fix it onto the recording sheet; and a control circuit to determine a target fixing temperature of the fixing device based on the detection values stored in the memory. The control circuit determines the target fixing temperature for successive recording sheets depending on the detected smoothness, and resets the detection values stored in the memory to zero when the status sensors detect a change in the storage status of the paper trays.

Image forming apparatus

A fixing device includes an endless fixing belt, fixing-belt holding members which hold the fixing belt at opposite ends, a pressure member to be brought into contact with the fixing belt, a nip forming member arranged inside the fixing belt to form a nip area by contacting the pressure member with the fixing belt, a nip supporting member, side plates where the fixing-belt holding members and the nip supporting member are fixed, and a pressing mechanism which presses the pressure member against the nip forming member. The nip forming member includes at least three layers including a heat absorbing layer contacting the nip supporting member. With no load applied, the nip supporting member assumes a shape protruding at longitudinal center toward the pressure member and is in contact with the nip forming member while having the shape protruding at the center portion.

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Kanagawa, Japan

Motoyoshi Yamano