Ricoh Company, Ltd.

Ryuuichi Mimbu

Toshihiko Shimokawa

Kazuya Saito

Yutaka Ikebuchi

Shuutaroh Yuasa

Hiroshi Yoshinaga

Yuji Arai

Takayuki Seki

Yoshiki Yamaguchi

Shuntaro Tamaki

Masaaki Yoshikawa

Akira Suzuki

Takahiro Imada

Takuya Seshita

Kensuke Yamaji

Hajime Gotoh

Kenji Sengoku

Yoshio Hattori

Osamu Ichihashi

Junpei Fujita

Takeshi Yamamoto

Hiromasa Takagi

Yasunori Ishigaya

Haruyuki Honda

Shuntaroh Tamaki

Keitaro Shoji

Kenji Ishii

Tadashi Ogawa

Arinobu Yoshiura

Teppei Kawata

Ryohei Matsuda

Takamasa Hase

Naoki Iwaya

Takeshi Uchitani

Masahiko Satoh

Shinichi Namekata

Koichi Kudo

Yoshihiro Sakai

Hiromi Ogiyama

Toshiyuki Andoh

Katsuya Kawagoe

Junya Takigawa

Toshiharu Hachisuka

Takuroh Kamiya

Shinya Tanaka

Keigo Nakamura

Hirokazu Ishii

Yasunobu Shimizu

Yuji Kato

Yasufumi Takahashi

Satoshi Kuno

Junroh Uda

Jumpei Fujita

Kentaro Yamanaka

A fixing device includes a fixing rotator over which a recording medium bearing an image is conveyed. A first heater heats the fixing rotator and generates heat evenly in a maximum conveyance span where the recording medium having a maximum width in a width direction of the recording medium is conveyed. The maximum width is available for the fixing rotator. A second heater heats the fixing rotator and generates heat in the maximum conveyance span. The second heater includes a first portion that generates heat in a first heat generation amount and a second portion that generates heat in a second heat generation amount that is greater than the first heat generation amount of the first portion.

Fixing device with controlled heating and image forming apparatus

A disclosed fixing device includes a pressing member; an endless tubular fixing member disposed opposite to the pressing member; a heating source configured to heat the fixing member; a nip forming member disposed opposite to the pressing member via the fixing member to form a nip portion; and a supply unit configured to supply lubricant to a portion of an inner surface of the fixing member, the portion facing the nip forming member, wherein the nip forming member includes a contact portion that contacts the inner surface of the fixing member, the contact portion includes a guide portion for guiding lubricant, and the guide portion is formed by extending obliquely from opposite ends in a width direction toward a center of the fixing member as the contact portion moves from upstream to downstream in a rotational direction of the fixing member.

Fixing device with nip forming member having guide portions

A fixing device includes a rotatable endless belt formed into a loop and a heater disposed opposite the endless belt to heat the endless belt. A nip formation pad is disposed inside the loop formed by the endless belt. The nip formation pad includes a metallic thermal equalizer extending in an axial direction of the endless belt. A rotatable pressure rotator presses against the nip formation pad via the endless belt to form a fixing nip between the endless belt and the pressure rotator, through which a recording medium bearing a toner image is conveyed. The pressure rotator includes an increased tackiness portion disposed at a lateral end of the pressure rotator in an axial direction of the pressure rotator to transmit a driving force to the endless belt. The increased tackiness portion is disposed opposite the thermal equalizer of the nip formation pad.

Fixing device and image forming apparatus

A fixing device includes an endless fixing belt that is multilayered, an opposing rotator disposed opposite the fixing belt and pressed to the fixing belt to form a nip, a heater disposed inside the fixing belt, and a safety device including a contactless temperature sensor disposed outside the fixing belt and apart from an outer face of the fixing. The fixing belt is to rotate and thermally expand. The contactless temperature sensor detects a temperature of the fixing belt. The safety device stops heating by the heater when the temperature detected by the contactless temperature sensor is at or higher than a predetermined temperature. As the outer face of the fixing belt shifts outward in the radial direction due to thermal, a proportion of the outer face of the fixing belt in a viewing angle of the contactless temperature sensor increases.

An image forming apparatus includes a fixing device to fix a toner image onto a recording medium, a voltmeter to measure an input voltage from an external source, and a controller operatively connected to the fixing device and the voltmeter. The fixing device includes an endless, fixing rotator formed into a loop, a heater to heat the fixing rotator, a pressure pad disposed inside the loop, and a pressure rotator disposed opposite the pressure pad via the fixing rotator to press the fixing rotator against the pressure pad to form a fixing nip between the fixing rotator and the pressure rotator, through which the recording medium bearing the toner image is conveyed. The controller controls a heating operation of the heater and a fixing operation of the fixing device to fix the toner image onto the recording medium, based on the input voltage measured by the voltmeter.

Image forming apparatus incorporating fixing device

A fixing device includes a heat source; a fixing member looped into a generally cylindrical shape to rotate in a circumferential direction thereof and partially heated by the heat source and to heat a surface of a recording medium bearing an unfixed toner image to fix the unfixed toner image thereon in a fixing process; a rotary pressing member disposed facing the fixing member to form a nip therebetween, through which the recording medium is transported in a transport direction; and a rotation driver to rotate one of the fixing member and the pressing member. In a case in which the fixing member is halted for a reason other than the fixing process while power of the fixing device is on, electric power is not supplied to the heat source and the fixing member is rotated by a predetermined amount or more after the fixing member is halted.

Fixing device and image forming apparatus including same

A fixing device has a flexible endless fixing member; a heater to heat the fixing member; a nip forming member to contact the fixing member directly or via a slide member; a pressure member, rotatably disposed opposite the fixing member and the nip forming member; and a back curl correction structure that includes a drive roller disposed on a side where a back curl appears in the recording sheet; a driven roller disposed opposite the drive roller; an auxiliary nip portion to feed the recording sheet; a guide member to guide the recording sheet fed out from the auxiliary nip portion to bend in a direction opposite a curled direction of the back curl of the recording sheet. A driving connection between the drive roller and the pressure member is performed by a connection between a drive roller side connection gear and a pressure member side connection gear.

Fixing device and image forming apparatus including the same

An image forming apparatus includes an image forming device to transfer an image to a recording sheet; a fixing device to feed the recording sheet and fix the image onto the recording sheet; a branching device to switch between an ejection path to eject the recording sheet fed downstream of the fixing device, to outside the apparatus, and a reversing path for duplex printing; and a back curl correction structure disposed in a sheet feeding path between the fixing device and the branching device. The back curl correction structure includes a drive roller; a driven roller; an auxiliary nip portion; a guide member; and a guide moving device to move the guide member to a first position and a second position depending on the condition of the recording sheet.

Image forming apparatus

A fixing device includes an endless fixing belt; a pressure roller to contact the fixing belt; a nip forming member to press the pressure roller from the fixing belt; a nip portion formed between the fixing belt and the pressure roller; a heater to heat the fixing belt to fuse and fix toner onto a recording sheet in the nip portion; an auxiliary driven roller; an auxiliary drive roller to drive the driven roller; an auxiliary nip portion, formed between an outer circumferential surface of the auxiliary driven roller and an outer circumferential surface of the auxiliary drive roller, to nip the recording sheet after toner fixation conveyed from the nip portion; and an outlet guide member, disposed downstream of the auxiliary nip portion, to guide the recording sheet after toner fixation conveyed from the auxiliary nip portion, with the toner-fixed recording sheet surface bent in a concave shape.

Fixing device including outlet guide member and image forming apparatus thereof

An image forming apparatus includes a first heater disposed opposite and heating at least a center of a fixing belt in an axial direction thereof and a second heater disposed opposite and heating at least a lateral end of the fixing belt in the axial direction thereof. A power supply supplies power to the first heater and the second heater. A controller that controls the power supply includes a calculator to calculate an elapsed time elapsed after at least one of the first heater and the second heater starts heating the fixing belt. The controller controls the power supply to supply power to the first heater and the second heater such that a power density of the second heater is greater than a power density of the first heater when the elapsed time calculated by the calculator is smaller than a predetermined time.

Image forming apparatus and image forming method

A fixing device includes a fixing member; a heater to heat the fixing member; a nip forming member to contact the fixing member; and a pressure member, disposed opposite the nip forming member to press against the fixing member to form a fixing nip portion together with the nip forming member. The fixing device applies heat and pressure to fix an image transferred to a recording sheet when the recording sheet passes through the fixing nip. The nip forming member includes a first and second planar portions disposed at an upstream end and a downstream end, respectively, of the fixing nip portion, and the first planar portion and the second planar portion are continuous with a curved portion of the nip forming member. A guide member guides the recording sheet to bend in a direction opposite a back curl of the recording sheet generated in the fixing nip portion.

A fixing exit guide plate for use in a fixing device, which supports the conveyance of a paper while being curved in a direction opposite to a curl direction of the paper in a paper conveyance path downstream of conveyance support rollers, includes a conveyance downstream portion having a paper conveyance plane and a conveyance upstream portion having a paper conveyance plane, wherein the fixing exit guide plate is retracted in a paper jam process to move such that the paper conveyance plane of the conveyance downstream portion rotates about a rotation axis of the conveyance support driving roller to be substantially parallel to the paper conveyance plane of a conveyance upstream portion.

Fixing exit guide plate, fixing device, and image forming apparatus

A fixing device includes a fixing rotator, a first heat generator and a second heat generator that heat the fixing rotator, and a support disposed inside the fixing rotator. A reflector, interposed between the support and each of the first heat generator and the second heat generator, reflects light radiated from the first heat generator and the second heat generator toward the fixing rotator. The reflector includes a body mounted on the support and a shield portion projecting from the body toward the first heat generator and the second heat generator to shield the fixing rotator from the first heat generator and the second heat generator. An electric circuit is connected to the first heat generator and the second heat generator. A heat generation restrainer is provided in the electric circuit to restrict heat generation in the electric circuit.

An image forming apparatus includes a fixing rotator and an opposed rotator pressed against the fixing rotator to form a fixing nip therebetween, through which a recording medium bearing a toner image is conveyed. A heater heats the fixing rotator. A temperature sensor contacts the opposed rotator to detect a temperature of the opposed rotator. A conveyor conveys the recording medium to the fixing nip. A driver drives the conveyor. A controller, operatively connected to the temperature sensor and the driver, controls the driver to drive the conveyor to convey the recording medium to the fixing nip based on the temperature of the opposed rotator detected by the temperature sensor. The controller causes the driver to be ready to drive the conveyor when a change in the detected temperature of the opposed rotator per unit time reaches a predetermined threshold.

Growing community of inventors

Kanagawa, Japan

Ryuuichi Mimbu