Ricoh Company, Ltd.

Hideo Nagafuji

Arinobu Yoshiura

Kohichi Utsunomiya

Motoyoshi Yamano

Yutaka Ikebuchi

Yuji Arai

Shohei Saito

Qifeng Cui

Kiho Sai

Kenji Ishii

Hiromasa Takagi

Keitaro Shoji

Hiroshi Ono

Takayuki Seki

Tetsuo Tokuda

Yoshikuni Sasaki

Shingo Kuboki

Ryohhei Sugiyama

Daisuke Sawada

Hironori Yamaoka

Yuuki Nobuoka

Takahiro Kikuchi

Yuichi Harashima

Satoshi Endoh

Yohichi Tsukamoto

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 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 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

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.

A paper conveyance device comprises: a conveyance member having a conveyance surface for conveying a recording medium, the conveyance member extending in a first direction along a front-rear direction of the image forming apparatus that has an opening member for exposing inside of the apparatus, and including a handle disposed on an exposure surface of the opening member, and a swing pivot point that is used to swing the conveyance member around the first direction to expose the conveyance surface when the handle is operated in the open state. The handle is disposed in at least one position in a range between positions near a center of the conveyance member in the first direction. The positions are a certain distance away from the center of the conveyance member along the first direction.

Paper conveyance device, fixing device, and image forming apparatus

A fixing device includes: a rotatable endless belt type fixing member; a pressurizing member that is opposed to the fixing member and rotates; and a nip forming member that is arranged inside the fixing member, and forms a nip part by contact with the pressurizing member through the fixing member. The nip forming member includes: a heat-uniformizing member having bent portions opposed to each other; a heat-insulating member arranged inside the heat-uniformizing member; a heat-absorbing member arranged on an upper surface of the heat-insulating member; and a sliding sheet that covers a nip side of the heat-uniformizing member, and is held between the bent portions of the heat-uniformizing member and the heat-insulating member. The heat-uniformizing member and the heat-insulating member are fastened to each other by fitting a fitting part formed on the heat-uniformizing member to a fitted part formed on the heat-insulating member.

A fixing device includes: a rotatable fixing member formed as an endless belt; a heat source to heat the fixing member; a nip-forming member being not rotatable and arranged inside the fixing member; and a pressure member arranged outside the fixing member and forming a nip between the pressure member and the fixing member. The nip-forming member is formed of a first heat transmission unit and a sliding sheet. The first heat transmission unit includes an abutting part abutting the fixing member with the sliding sheet therebetween, and a bent part or bent parts extending inside the fixing member at upstream or upstream and downstream of the nip in a transport direction of a recording medium. A retaining part to catch and retain the sliding sheet is provided at a tip of at least the bent part at upstream of the nip in the transport direction.

A heating device is used in an image forming apparatus. In the heating device, a resin layer is provided between a core metal of a fixing roller and a ball bearing. The resin layer is adhered to the core metal so as to obviate a noise, caused by a rubbing of the resin layer against a ball bearing, which is otherwise produced when the resin layer is provided as a separate part. Between the resin layer and the ball bearing, a material of the resin layer is selected and the resin layer is configured to have a rough surface with a coefficient of dynamic friction of the surface of the resin which is a predetermined value, and thereby minimizing the production of the noise.

Heating device having resin layer over core metal of heating roller

A heating device is used in an image forming apparatus. In the heating device, a resin layer is provided between a core metal of a fixing roller and a ball bearing. The resin layer is adhered to the core metal so as to obviate a noise, caused by a rubbing of the resin layer against a ball bearing, which is otherwise produced when the resin layer is provided as a separate part. Between the resin layer and the ball bearing, a material of the resin layer is selected and the resin layer is configured to have a rough surface with a coefficient of dynamic friction of the surface of the resin which is a predetermined value, and thereby minimizing the production of the noise. The outer diameter of the portion of the heat roller supported by the bearing is larger than the portion of the heat roller that contacts a heated member.

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Kanagawa, Japan

Hideo Nagafuji