Ricoh Company, Ltd.

Other

Tohoku Ricoh Co., Ltd.

Toshiaki Higaya

Hiroshi Yokoyama

Tomotaka Takamura

Tadashi Ogawa

Masahiko Sato

Yutaka Takahashi

Hiroshi Seo

Masae Sugawara

Akiko Ito

Akiko Miyahara

Takayuki Seki

Tadashi Kasai

Mitsuo Aoki

Masanao Ehara

Yasushi Koichi

Kumi Hasegawa

Keizou Yasuda

Jyunji Nakai

Yuzou Kouno

Jun Okamoto

Yutaka Fukuchi

Hideaki Mochimaru

Kenzo Ariyama

Yasukuni Omata

Masaaki Ogura

Norimasa Sohmiya

Mitsuru Seto

Eiji Sawamura

Toshiyuki Ogawa

Nachio Seko

Atsushi Arai

Masanori Matsuda

Yuzo Kouno

Mituo Aoki

Takato Yano

Kiyozo Hashizume

Yukiti Shindou

An image forming apparatus includes an image carrier to carry a toner image and a fixing device to fix the toner image transferred from the image carrier onto a recording medium by applying at least heat to at least one of the toner image and the recording medium. Such a fixing device includes: a magnetic flux generator to generate a magnetic flux; and a heat generating member disposed at least partially in the magnetic flux. The heat generating member includes a heat generating layer to generate heat via eddy currents therein induced by the magnetic flux, magnitudes of the eddy currents varying according to positions thereof in a width direction of the heat generating layer. Included within the heat generating layer is a magnetic layer having a Curie point in a range, e.g., from about 100 degrees centigrade to about 300 degrees centigrade.

Image forming apparatus and fixing device

A fixer configured to fix an image on an recording medium passing through a fixing nip includes a holder including an elastic layer, a fixing rotator including a heating layer, provided overlying the holder, and a pressurizer configured to pressurize the holder via the fixing rotator to form the fixing nip. A part of the pressurizer, which forms the fixing nip, has a length not less than a length of the heating layer in a width direction perpendicular to a conveyance direction of the recording medium.

Fixer and image forming apparatus including the same

An image forming apparatus includes a fixing unit for fixing a toner image on a recording sheet. In the fixing unit, a magnetic flux generator generates magnetic flux to induce heat in a fixing roller. The recording sheet having the toner image is inserted between the fixing roller and a pressure roller pressingly contacting the fixing roller. The fixing roller applies heat to the recording sheet. The pressure roller applies pressure to the recording sheet. The heat and pressure fix the toner image on the recording sheet. The magnetic flux generator is disposed to face outer and inner circumferential surfaces of the fixing roller. The magnetic flux generator is formed in a U-like or loop-like shape, and the fixing roller is placed in a gap or a loop of the magnetic flux generator. The magnetic flux generator may include a single wire.

Method and apparatus for image forming capable of effective image fixing using induction heating

An image forming method, comprising passing a toner image-bearing sheet through a nip defined between two rollers including a heater roller to fix the toner image on the sheet, wherein the toner image is formed from a toner comprising a binder resin, and a colorant, wherein the toner image before the passage through the nip has a toner volume Vand a toner image area S, wherein the toner image after the passage through the nip has a toner volume Vand a toner image area S, and wherein a volume change Vt and an area change St defined by the formulas shown below are 30% or less and 20% or less, respectively:(%)=(1&#x2212;2)/1&#xd7;100(%)=(2&#x2212;1)/1&#xd7;100.Alternatively, the toner image before the passage through the nip has a surface roughness of 2.5 &#x3bc;m or less.

Image forming method and toner for use in the method

An induction heating type fixing device for an electrophotographic image forming apparatus is disclosed. An inducting heating coil has a plurality of bobbins each having a particular diameter and assembled in a telescopic manner. A particular conductor is wound round each bobbin beforehand with leads being laid inside of the conductor. The bobbin may be implemented as a plurality of bobbin members removably connected together.

Induction heating type fixing device for an image forming apparatus and induction heating coil therefor

An image forming method, comprising passing a toner image-bearing sheet through a nip defined between two rollers including a heater roller to fix the toner image on the sheet, wherein the toner image is formed from a toner comprising a binder resin, and a colorant, wherein the toner image before the passage through the nip has a toner volume Vand a toner image area S, wherein the toner image after the passage through the nip has a toner volume Vand a toner image area S, and wherein a volume change Vt and an area change St defined by the formulas shown below are 30% or less and 20% or less, respectively:(%)=()/(%)=()/Alternatively, the toner image before the passage through the nip has a surface roughness of 2.5 &#x3bc;m or less.

An image forming apparatus includes a first image bearing member, a second image bearing member, and a fixing device. A first visual image formed on the first image bearing member is transferred onto the second image bearing member to be transferred from the second image bearing member onto a first side of a recording medium, and a second visual image formed on the first bearing member is transferred from the first image bearing member onto a second side of the recording medium, so that the visual images are obtained on the first and second sides of the recording medium respectively. The visual images on the first and second sides of the recording medium are fixed by the fixing device in a state that the second image bearing member and the recording medium are overlapped with each other.

Image forming apparatus and method for improving image quality of double sided prints

A device configured to be heated to a temperature sufficient to fuse an image forming substance to a sheet includes a hollow roller made of a conductive material and a coil arranged in a hollow portion of the hollow roller. The coil is configured to carry an electrical current that induces a current in the conductive material of the hollow roller such that the hollow roller becomes heated so as to fuse toner to a sheet. The coil is mounted on a member that is disposed in the hollow portion of the roller. The member includes various combinations of features that permit a reliable and safe operation of the induction heating apparatus such as recess and projections formed in the member to separate respective turns in the coil, a hollow center of the member that can be ventilated with a ventilation fan, and predefined gaps being maintained between the inside surface of the hollow roller and an outer surface of the coil.

Device with induction heating roller including projecting portions at both ends and a central portion of a bobbin for maintaining a gap between an inner surface of the heating roller and a coil on the bobbin

The present invention provides a fixing device that excels in thermal conversion efficiency, compared with an induction-type fixing device. In this fixing device, a peripheral surface of a roller facing an induction coil has concavities and convexities with edges. Where the induction coil is inserted into a core bar, the concavities and convexities are formed inside the core bar. Where the induction coil is located outside the roller, the concavities and convexities are formed on the outer periphery of the core bar.

Induction heating fixing device and image forming apparatus

A fixing device using induction heating for an electrophotographic image forming apparatus includes a heat roller and a press roller for fixing a toner image on a recording medium while conveying the recording medium. A coil unit is located outside of the heat roller and upstream of a nip between the heat roller and the press roller in the direction of rotation of the heat roller for generating an induced magnetic flux. The coil unit concentratedly heats the heat roller and thereby efficiently feeds heat to the recording medium.

Fixing device using induction heating for image forming apparatus

An induction heating type fixing device for an electrophotographic printer, facsimile apparatus, copier or similar image forming apparatus and an induced current generating member therefore are disclosed. A coil is wound round a bobbin applied with an adhesion preventing material. After the coil has been adhered by nonconductive adhesive by impregnation, the coil and bobbin subassembly is inserted into a hollow cylinder body formed of a heat-resistant insulating material. After the coil has been adhered to the cylindrical body, the bobbin is pulled out to produce the induced current generating member.

Induction heating type fixing device and method of producing an induced current generating member therefor

Device with induction heating roller with a projection between coil windings

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Kawasaki, Japan

Toshiaki Higaya