Konica Minolta Business Technologies, Inc.

Minolta Company, Ltd.

Konica Minolta, Inc.

Minolta Camera Kabushiki Kaisha

Noboru Yonekawa

Naoki Yamamoto

Toru Hayase

Mamoru Fukaya

Kouji Matsushita

Yasuhiro Nakagami

Satoru Yoneda

Mitsuru Isogai

Takashi Yamada

Yuusuke Morigami

Yutaka Otsuka

Eiji Okabayashi

Katsuhiko Takeda

Shizuo Yuge

Noboru Ito

Tetsuro Ito

Hirotaka Kanou

Taizou Oonishi

Yasunori Nakayama

Yoshihiro Shojo

Kazuo Mohri

Shigeo Nakamura

Ryo Kawamura

A fixing device comprising: an endless fixing belt having a multilayer structure including a non-magnetic conductive layer and a first magnetic conductive layer, the non-magnetic conductive layer having a thickness smaller than a skin depth of a material thereof, the first magnetic conductive layer having a thickness smaller than a skin depth of a material thereof and being located farther from an outside surface of the fixing belt than the non-magnetic conductive layer; and a supporting member disposed inside the endless fixing belt and including a second magnetic conductive layer having a thickness larger than a skin depth of a material thereof. The first magnetic conductive layer and the second magnetic conductive layer have a higher specific resistance than the non-magnetic conductive layer, and the first magnetic conductive layer has been manufactured by plastic forming or plating.

Fixing device and image formation apparatus

A fixing device for thermally fixing an unfixed image onto a recording sheet by causing the sheet to pass through a fixing nip. The fixing device includes: heat belt formed in an endless shape and provided with a resistance heat layer; first pressure member provided inside a running path of the heat belt; and second pressure member pressing the first pressure member from over the running path to form the fixing nip. At least one of the first and second pressure members is rotating body. The heat belt has a pressure-receiving area and two non-pressure areas. The pressure-receiving area receives pressures from both the first and second pressure members. The non-pressure areas have been arranged at outside of the pressure-receiving area in an axis direction of the rotating body. Two ring-like electrodes have been formed on circumferential surfaces of the non-pressure areas and are used to supply power to the resistance heat layer.

Fixing device and image forming apparatus

A fixing device for thermally fixing an unfixed image formed on a recording sheet by passing the recording sheet through a fixing nip. The fixing device has a heat-generating endless belt that includes: a resistive heat layer that generates heat upon receiving electric current; and a pair of electrode layers each disposed along a different one of widthwise edges of the heat-generating endless belt. The resistive heat layer has (i) reduced thickness portions each along a widthwise edge thereof and (ii) a middle portion between the reduced thickness portions. Each reduced thickness portion is thinner than the middle portion and connected to the middle portion with a wall surface upright in a direction perpendicular to the rotation axis of the heat-generating endless belt to define a stair shape. Each electrode layer is disposed on the resistive heat layer to be in contact with a corresponding one of the wall surfaces.

Fixing device and image forming apparatus with a mechanism to extend a life of a fixing belt

A fixing device for thermally fixing an unfixed image formed on a recording sheet by passing the recording sheet through a fixing nip. The fixing device has: a heat-generating endless belt having, on a circumferential surface thereof, a sheet passing area through which the recording sheet passes; a first pressure member disposed inside a running path of the endless belt; and a second pressure member disposed to press the endless belt against the first pressure member from outside the running path to form the fixing nip. The endless belt includes: a resistive heat layer that generates heat upon receiving electric current; and a pair of electrode layers that receive electric current. The electrode layers flank the sheet passing area. The resistive heat layer is in contact with the electrode layers at a different one of end faces opposing each other in a width direction of the resistive heat layer.

Fixing device and image forming apparatus with a mechanism to extend life of a fixing belt

Disclosed is a fixing device for thermally fixing an unfixed image onto the recording sheet, the fixing device comprising: a fixing belt; and a meander regulation member provided adjacent to an edge of the fixing belt in a width direction thereof, and operable to prevent meandering of the fixing belt, wherein the fixing belt includes: a resistive heat layer that is tubular and generates heat when an electric current is applied thereto; and first and second electrodes that are provided circumferentially on an outer circumferential surface of the resistive heat layer, and that receive and apply the electric current to the resistive heat layer, and the first electrode is provided closer to the meander regulation member than to the second electrode, and is at a distance from the edge of the fixing belt in the width direction thereof.

A fixing device includes: a heating rotary member having a heating layer generating heat upon current application; a pressurizing rotary member brought into pressure-contact with an outer circumferential surface of the heating rotary member to form fixing nip, through which a sheet on which unfixed toner image is formed passes for heat fixing; circular electrodes that are circumferentially formed at two respective positions sandwiching a sheet passing region therebetween, on the outer circumferential surface, and feed electrical power to the heating layer, the electrodes are each metallic and formed of at least two electrode layers including a first electrode layer layered directly on the heating layer and a second electrode layer as an outermost layer, linear expansion coefficient difference between the first layer and the heating layer is smaller than that between the second layer and the heating layer, and the second layer is more oxidation-resistant than the first layer.

Provided is a fixing device that uses an induction heating method and is capable of shortening a warm-up time period by accelerating the speed of increase in the temperature of a fixing belt. The fixing device forms a fixing nip by having a pressurizing roller pressurize a fixing roller, which is positioned inside a rotation path of a fixing belt having a hollow cylindrical shape, from outside the rotation path via the fixing belt. Given that Db is an inner diameter of the fixing belt, Dr is an outer diameter of the fixing roller, and a rate X is a value obtained by dividing the inner diameter Db of the fixing belt by the outer diameter Dr of the fixing roller, the fixing belt and the fixing roller that satisfy a relationship 0&#x3c;X&#x2266;1.18 are used.

Fixing device and image forming apparatus comprising the same

An induction heating unit enabling to attaching coil on coil attaching surface of bobbin with a high degree of accuracy, and a fixing device capable of maintaining the distance between the coil and the member to be heated at a high degree of accuracy, ensuring uniformity of temperature distribution of the member to be heated, rising temperature at a high speed, and enhancing quality of fixation. In an induction heating unitincluding a magnetizing coilattached on a coil bobbinwhich is disposed outside of annular bodyto be heated, the unit including: a layer of elastic adhesiveprovided on the outer surface of the coil bobbin; a magnetizing coilprovided on the layer of elastic adhesive, the magnetizing coilbeing wound beforehand following an attaching surface; and a layer of elastic adhesiveprovided on the magnetizing coil

Induction heating unit, fixing device and method for attaching coil for induction heating unit

A heat generating sleeve () having a high ability to control an amount of heat generation of itself and sufficient strength comprises a heat controlling layer () consisting of annealed permalloy, and a main heating layer () consisting of unannealed metal plated on a surface of the heat controlling layer ().

Heat generating sleeve, fixing device and image forming apparatus

A heat generating roller which generates a heat when magnetic flux is applied from outside, which has high ability to control an amount of heat generation of itself and which has sufficient strength, including a main heating layer made of a material having a low electric resistivity, a heat controlling layer made of magnetic metal including at least nickel, a heat insulation layer having a low heat conductivity, and a stiff metal core, in order as above from outside, wherein the heat controlling layer is annealed, and the heat controlling layer and the heat insulation layer are bonded to each other.

Heat generating roller, fixing device and image forming apparatus

A fixing device thermally fixes an unfixed image on a recording sheet by passing the recording sheet through a fixing nip. The fixing device has: a heat-generating endless belt; a first pressure member inside a running path of the endless belt; a second pressure member pressing the endless belt against the first pressure member from outside the running path to form the fixing nip, and a pair of power feeders. The endless belt includes: a circumferential resistive heat layer that generates heat upon receiving electric current; and a first electrode and a second electrode flanking a sheet passing area of the circumferential surface of the endless belt. Each electrode is composed of a pair of electrode layers, one on the inner and another on the outer circumferential surface of the resistive heat layer. Each power feeder is in contact with both the electrode layers of a different electrode.

A belt-type fixing device is provided in which a nip pressure distribution in a fixing nip is made generally uniform with respect to a paper feeding direction and which thereby prevents occurrence of image noise even when a thick paper is fed. The belt-type fixing device has: an endless-sheet-like fixing belt, a pressurizing roller which has elasticity and on which a paper is passed through a fixing nip that is contact part between the pressurizing roller and an outer circumferential surface of the belt member, and a nip forming member which is provided in contact with an inner surface of the fixing belt, which relatively presses the fixing belt against the pressurizing roller, of which an opposite surface pressing the pressurizing roller is formed as a curved surface extending along an outer circumferential surface of the pressurizing roller, and of which the opposite surface is composed of an elastic layer.

Belt-type fixing device

A belt-type fixing device is provided in which a wide fixing nip having a generally flat pressure distribution with respect to a paper feeding direction can be formed. The belt-type fixing device of the invention has a nip forming member that is fixed inside an endless-sheet-like fixing belt to be heated so as to be incapable of rotating, and a rotatable pressurizing roller that is in pressure contact with the nip forming member with the fixing belt interposed between. Contact part between the fixing belt and the pressurizing roller forms a fixing nip, and a surface of the nip forming member that is opposite to the pressurizing roller is configured as a curved surface extending along an outer circumferential surface of the pressurizing roller so that a pressure distribution in the fixing nip is made generally flat with respect to the paper feeding direction.

A corona discharge device used in an electrophotographic image forming apparatus includes a discharge member such as a saw-toothed discharge member having sharp discharge ends, and a power supply which applies to the discharge member a discharge voltage containing at least an AC voltage component, wherein at least each discharge end portion of the discharge member is made of an electrically conductive material, which contains nickel and chromium, and/or is coated with a material having a high electric resistance. In the case where the saw-toothed discharge member is employed, a distance D between the discharge end and a member to be charged, and a discharge end pitch P are determined to satisfy a relationship of 2&lE;D/P&lE;8.

Corona discharge device

A fixing apparatus for controlling an oil transfer apparatus to maintain a releasing agent holding layer such that it is not always saturated with the releasing agent. This makes it a compact, cost-effective unit with a long service life and provides a uniform, stable oil coating that eliminates image noise problems. In order to use a constant and minimum necessary amount of releasing agent, a releasing agent supply nozzle is incorporated with multiple protrusive or retrusive droplet growth assisting members at or near multiple releasing agent discharge ports. The supply nozzle used for supplying the oil has multiple discharge holes having approximately equal opening cross-sectional areas and an equalizing member which equalizes the amount of oil discharged from each discharge hole. The outer diameter D1 of the oil supply roller, the outer diameter D2 of the metal core and the distance P of adjacent through-holes formed on the periphery of the metal core satisfy a relation, 0.6&lt;D1.multidot.(D1-D2)/(D2.multidot.P)&lt;6. A quantifying apparatus is provided to equalize the amount of oil transferred by the oil pump when it is intermittently transferred. The quantifying apparatus contributes in achieving a constant amount of releasing agent coating. A releasing agent leakage prevention member is provided to prevent unnecessary oil leakage from the releasing agent supply nozzle and rollers. A specific correlation is established between the centerline average roughness of the oil supply roller surface and the amount of the releasing agent supply to the fixing roller by the oil supply roller. This makes it possible to achieve a uniform coating with excellent releasing capability and prevents adhesion of add particles.

Growing community of inventors

Toyohashi, Japan

Noboru Yonekawa