Abstract: An image heating apparatus has a coil for generating magnetic flux, a rotatable heat generation member which generates heat by magnetic flux, a temperature detecting member for detecting a temperature of the heat generation member, an energization controller portion for controlling energization to the coil on the basis of an output of the temperature detecting member, a first magnetic flux shielding portion for blocking, in a first magnetic flux adjustment position, the magnetic flux directed toward a central portion of heat generation member, while permitting the magnetic flux directed to an end portion, and a second magnetic flux shielding portion for blocking, in a second magnetic flux adjustment position, the magnetic flux directed toward an end portion of the heat generation member, a moving unit for moving the first magnetic flux shielding portion and the second magnetic flux shielding portion, and a recovery operation controller portion for retracting the second magnetic flux shielding portion from the

Abstract: In a fixing apparatus using an induction heating type of heating apparatus, there are provided an excitation apparatus that generates magnetic flux, an opposed core located opposite the excitation apparatus, a fixing belt that is induction-heated by the aforementioned magnetic flux, and magnetism masking elements that block magnetic paths corresponding to paper non-passage areas of fixing belt between the excitation apparatus and the opposed core. By blocking magnetic paths between the excitation apparatus and the opposed core by the magnetism masking elements, magnetic flux that induction-heats the fixing belt is effectively masked, and an excessive rise in temperature of paper non-passage areas of fixing belt is prevented.

Abstract: An induction heating coil of an induction heating device of the invention is formed such that a first coil width of an active coil section parallel to a longitudinal direction of a heat roller and a second coil width of an end coil section in a direction parallel to a rotating direction of the heat roller are different. When the induction heating coil is divided into plural coils, portions having weak magnetic fields in joint portions of the induction heating coils, at both ends of the induction heating coils, or the like are narrowed.

Abstract: An image heating apparatus is provided that enables the entire width of a heat-producing medium to be heated uniformly and an excessive rise in temperature to be prevented, without making the configuration complex. In a fixing unit 19 in which this apparatus is applied, a fixing belt 112 is an annular member that has an inner peripheral surface and an outer peripheral surface, and produces heat through the action of magnetic flux. An exciting coil 120 is located in proximity to the outer peripheral surface of fixing belt 112, and generates magnetic flux that acts upon fixing belt 112. A suppression member 650 is located in proximity to inner peripheral surface of fixing belt 112, and reduces, of the magnetic flux generated by exciting coil 120, magnetic flux that acts upon a paper non-passage area of fixing belt 112.

Abstract: A fixing device includes an excitation coil, a heat-generating layer, a magnetic shunt layer, and a degaussing member. The excitation coil generates a magnetic flux. The heat-generating layer generates heat using the magnetic flux generated by the excitation coil. The magnetic shunt layer transmits heat generated by the heat-generating layer. The degaussing member sandwiches the magnetic shunt layer together with the excitation coil, and selectively performs degaussing by generating a repelling magnetic flux for canceling the magnetic flux generated by the excitation coil so as to activate a self-temperature-control function. The degaussing member selectively refrains from degaussing so as to deactivate the self-temperature-control function.

Abstract: A heating device includes a magnetic field generating unit, and a heat generating body having a heat generating layer generating heat due to electromagnetic induction, and a temperature-sensitive layer. The heat generating layer is disposed opposing the magnetic field generating unit. The temperature-sensitive layer has a Curie temperature greater than or equal to a set temperature of the heat generating layer and less than or equal to a heat-resistant temperature of the heat generating layer, and is disposed at a side of heat generating layer opposite a side where the magnetic field generating unit is disposed such that heat from the heat generating layer is conducted. At temperatures lower than the Curie temperature, the temperature-sensitive layer causes the magnetic field to penetrate in from the heat generating layer, and at temperatures greater than or equal to the Curie temperature, causes magnetic flux of the magnetic field to pass therethrough.

Abstract: A fixing apparatus includes a mold (holding member) formed by injection molding to hold a coil so that the coil maintains a predetermined positional relation with respect to a heating roller, and capable of holding a temperature sensor which detects a temperature of the heating roller and a thermostat which detects an abnormal temperature of the heating roller in predetermined positions facing the heating roller.

Abstract: A fixing apparatus that enables the calorific value of a heat-producing rotating element to be stabilized and the heat production efficiency of that heat-producing rotating element to be improved. A fixing apparatus (200) is equipped with a heat-producing sleeve (210), an induction heating apparatus (230), a magnetic field absorption member (233) that absorbs a magnetic field generated by the induction heating apparatus (230), and a fixing roller (240) and pressure roller (250) that grip and rotate the heat-producing sleeve (210). The magnetic field absorption member (233) is located in an area opposite an exciting coil (231) with the heat-producing sleeve (210) between, and absorbs a magnetic field generated by the induction heating apparatus (230). The heat-producing sleeve (210) is composed of a nonmagnetic metallic material of thickness in the range from 10 ?m to 500 ?m and specific resistance of 80×10?6 ?cm or less.

Abstract: A thermal processing roller includes a heat transfer medium flowing path therein and heats a member to be processed abutting against a surface of the roller or absorbs heat therefrom by heat transfer fluid flowing through the heat transfer medium flowing path, wherein a sealed chamber extending in a longitudinal direction of the roller and in which heat transfer medium of vapor-liquid two phases is sealed is formed within a thick portion of the roller.

Abstract: In an aspect of this invention, a fixing device includes a heating member including a first area and a second area formed of conductive members (e.g., aluminum and iron) having different magnetic permeability ratios, and an induction heating unit which generates a magnetic field from a coil to induction-heat this heating member, and the fixing device changes a frequency of a high-frequency current to be supplied to the coil to thereby control a heating area of the heating member.

Abstract: A fixing device of an image forming apparatus includes a fixing roller rotatably mounted on a moving path of a printing medium having a toner image transferred thereon to fuse the toner image on the printing medium, a heater mounted in the fixing roller to generate a magnetic field by applied voltage, thus heating the fixing roller, and at least one magnetic core disposed around the fixing roller to concentrate, onto the fixing roller, the magnetic field generated by driving the heater. Accordingly, a density difference of the magnetic field generated by the heater is minimized by disposing the at least one magnetic core around the fixing rollers, thus enabling a uniform fixing temperature.

Abstract: An image fixing device inductively injects thermal energy into a rotating printing form of a press for fixing an image formed on the rotating printing form by means of a digital imaging system. The fixing device has at least one inductor with at least one induction loop, a high-frequency part that forms a tuned circuit with the inductor, and a supply part that can be coupled to the inductor by means of supply lines suitable for high frequency. The inductor loop is in an elongated form aligned parallel to the circumferential direction of the rotating printing form, with the effect that the zone of energy transfer and therefore the heating zone can be configured specifically in terms of its spread in the printing form, so that a high flux density can be introduced zonally into the printing form at the point which is to be heated.

Abstract: A manufacturing method for an image heating apparatus for heating an image on a recording material by a heat from a heat generating element for producing heat by a magnetic flux generated by magnetic flux generating means, the apparatus including a magnetic flux confining member for confining a magnetic flux directing toward a predetermined region of the heat generating element from the magnetic flux generating means, and a first drive transmission member, provided at one end of the magnetic flux confining member, for transmitting rotational drive to the magnetic flux confining member and a second drive transmission member, provided at the other end of the magnetic flux confining member, for transmitting rotational drive to the magnetic flux confining member, the method comprising an adjusting step of adjusting such that first and second drive transmission members are supported by the magnetic flux confining member with a predetermined rotational position relation, using marks provided on the first and second

Abstract: A heating apparatus includes a heat generation member for generating heat using magnetic flux; a coil for generating the magnetic flux by electric power supply thereto, the coil being disposed in the heat generation member, wherein a material to be heated is fed and introduced in a heating portion of the heat generation member to heat an image on the material to be heated by heat generated by the heat generation member; a movable member which is movable in the heat generation member; a rotatable drive transmission member for transmitting a driving force to the movable member, wherein the drive transmission member has a hollow rotation shaft, and a supply line for supplying the electric power is connected to the coil through the hollow rotation shaft.

Abstract: The present invention provides 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 unit 30 comprising a magnetizing coil 39 attached on a coil bobbin 38 which is disposed outside of annular body 19 to be heated, the unit comprising: a layer of elastic adhesive 44a provided on the outer surface of the coil bobbin 38; a magnetizing coil 39 provided on the layer of elastic adhesive 44a, the magnetizing coil 39 being wound beforehand following an attaching surface; and a layer of elastic adhesive 44b provided on the magnetizing coil 39.

Abstract: An image forming apparatus includes a fixing device which fixes a toner image on a recording medium. The fixing device includes a heating device. The heating device includes a heat-generating member, an exciting member, and a changing device. The heat-generating member is subjected to electromagnetic induction heating. The exciting member is placed to sandwich a front surface and a rear surface of the heat-generating member, without contacting the heat-generating member. The changing device changes an opposing distance of the exciting member to at least one of the front surface and the rear surface of the heat-generating member.

Abstract: In an image forming apparatus having a fixing rotor (22) that is driven to rotate and fixes an image by heating a recording paper while conveying the paper pressurized against the rotor, an excitation coil (24) that is provided extending in an axial direction along the fixing rotor (22) and causes induction heating by applying an alternating magnetic field to the fixing rotor (22), and a demagnetizing coil (25) that is provided superposed on an end of the excitation coil (24) and is able to partially diminish a magnetic flux generated by the excitation coil (24), by making the shape of the portion that belongs to the demagnetizing coil (25) and overlaps the excitation coil (24) has an asymmetrical shape have no axis of symmetry in the direction in which the recording paper is conveyed, a trouble due to overheating and defective fixing due to a shortage in the generation of heat can be reduced even when a plurality of kinds of recording papers of slightly different sizes are used.

Abstract: A fixing device is provided with a fixing member for thermally fixing a transferred toner image to a transfer material, and a pressing member held in contact with the fixing member to form a nip portion where the transfer material is caused to pass through, wherein the fixing member includes a nonmagnetic metal layer made of nonmagnetic metal, a temperature-sensitive metal layer made of temperature-sensitive metal, and an induction coil for induction heating by supplying magnetism toward the nonmagnetic metal layer and the temperature-sensitive metal layer. The thickness of the nonmagnetic metal layer is set such that an amount of heat produced by the fixing member is larger than an amount of heat evolved singly by the temperature-sensitive metal layer.

Abstract: There is provided a fixing device 6 including a heating body 22 which has a heating heat generation section 24 subjected to induction heating upon application of alternating magnetic fields generated by a exciting coil 27, a pressure roller 23 which has a pressing heat generation section 25 being higher in magnetic permeability than the heating heat generation section 24 and being subjected to induction heating by a part of magnetic flux in the alternating magnetic fields leaking from the heating heat generation section 24, and a drive circuit for applying drive voltage to the exciting coil, wherein a rate of the alternating magnetic fields leaking from the heating heat generation section 24 is changed by frequencies of the drive voltage.

Abstract: An image heating apparatus has a magnetic flux generator; a heat generating element for generating heat by a magnetic flux generated by the magnetic flux generator, the heat generating element being effective to heat an image on a recording material; an electric power supply for supplying electric power to the magnetic flux generator; electric power changing unit for changing electric power to be supplied to the magnetic flux generator on the basis of a temperature rise property of the heat generating element, in a period from start of electric power supply to the magnetic flux generator to reaching of a temperature of the heat generating element to a predetermined level.

Abstract: A fusing roller and a fusing apparatus having the same are provided. The fusing roller includes: an induced coil, which generates an alternating magnetic flux that varies depending on an input alternating current; a heating roller, which is heated by an eddy current that is generated by the alternating magnetic flux; and a compensator, which compensates for the eddy current generated where it is located.

Abstract: Provided are revolving hot roller(s) 31; heating means 33 for heating zonal portion(s) in direction(s) of revolution of hot roller(s) 31; thermistor(s) 35 which is/are temperature detection means for detecting temperature(s) of hot roller(s) 31; and control means 36 for controlling output(s) of heating means 33 based on temperature detection data from thermistor(s) 35; wherein at least one of the control means 36 has timing correction means for correcting timing(s) between temperature detection time(s) of thermistor(s) 35 and heating execution time(s) of heating means 33.

Abstract: According to a mode of the present invention, there is disclosed a fixing apparatus comprising a non-contact temperature detection section which detects a temperature by infrared rays radiated from a heating member, to made uniform a surface temperature of the heating member in an axial direction and a rotation direction based on first temperature information for detecting a temperature difference of the axial direction of the heating member and second temperature information for detecting the temperature difference of the rotation direction of the heating member.

Abstract: An electromagnetic induction coil unit for use with an electromagnetic induction heating-type image heating apparatus includes magnetic flux generation means comprising an exciting coil and a magnetic core; a core holder for holding the magnetic core; a coil holder for holding the exciting coil and the core holder holding the magnetic core; and a resin cured after being poured in a liquid state into a structure in which the exciting coil and the coil holder, and the magnetic fore and the core holder are incorporated so as to integrally mold the exciting coil, the magnetic core, the core holder, and the coil holder.

Abstract: An image heating device has a magnetic flux generator, a heat generating element for generating heat by a magnetic flux from the magnetic flux generator; a magnetic flux confining member, the magnetic flux confining member including a magnetic flux confining portion for confining the magnetic flux directed toward a predetermined region of the heat generating element at a predetermined magnetic flux confining position and a connecting portion connecting with the magnetic flux confining portion in a longitudinal direction of the heat generating element to hold the magnetic flux confining portion; and a moving unit for moving the magnetic flux confining member to a magnetic flux confining position or to a retracted position where the magnetic flux confining member is retracted from the magnetic flux confining position, wherein the connecting portion has a regulating member for preventing movement to the magnetic flux confining position.

Abstract: An image forming unit of a copier is provided with an image fixing unit (fixing device) adopting an induction heating method. A heating roller of this image fixing unit includes a heat producing layer made of a temperature-sensitive magnetic material whose permeability changes with temperature, and a supporting layer disposed adjacent to the heat producing layer and made of a nonmagnetic and electrically conductive material. The heat producing layer has a width substantially equal to a passing area (about 294 mm) for sheets along a direction of an axis of rotation of the heating roller and smaller than a width (about 310 mm) of an induction heating coil.

Abstract: In order to prevent non-sheet passing portion temperature rise occurred in a non-sheet passing area of an electromagnetic induction heating member 1, leakage of magnetic flux is reduced by setting a Curie temperature of the heating member 1 to be smaller than an acceptable upper limit temperature and setting a thickness of the heating member so that a thickness tk in a Curie temperature arrival area (P1-P2) is larger than a thickness tn in a Curie temperature non-arrival area P2 which is a conveyance area of a material to be heated having a minimum passing size.

Abstract: A fusing roller and a fusing apparatus using the same are provided. The fusing roller includes a coil unit resistance heated by a predetermined alternating current, and an alternating magnetic flux is generated by the alternating current. A heating roller unit is heated by an induced current generated by the alternating magnetic flux. End caps are installed on both ends of the heating roller unit and have electrodes for receiving power from an external power source. Reduction units are formed on both ends of the coil unit to reduce contact resistance generated when the coil unit contacts the electrodes.

Abstract: In a fixing device according to this invention, a coil bobbin around which coils are formed into a predetermined shape is formed at an induction heating portion including a plurality of coils. To minimize the axial temperature difference of a heating roller, the coil bobbin has a shape with which the interval between coils is held at a predetermined interval.

Abstract: Provided are revolving hot roller(s) 31; heating means 33 for heating zonal portion(s) in direction(s) of revolution of hot roller(s) 31; thermistor(s) 35 which is/are temperature detection means for detecting temperature(s) of hot roller(s) 31; and control means 36 for controlling output(s) of heating means 33 based on temperature detection data from thermistor(s) 35; wherein at least one of the control means 36 has timing correction means for correcting timing(s) between temperature detection time(s) of thermistor(s) 35 and heating execution time(s) of heating means 33.

Abstract: An image heating apparatus for heating an image on a recording material has a magnetic flux generator for generating a magnetic flux; a heat generation member for generating heat by the magnetic flux generated by the magnetic flux generator; a magnetic flux adjusting member for adjusting the magnetic flux acting on the heat generation member, wherein the heat generation member includes at least a metal layer having a thickness smaller than a thickness of a surface layer, and the magnetic flux adjusting member is disposed at a position across the magnetic flux generator from the heat generation member.

Abstract: A manufacturing method for an image heating apparatus for heating an image on a recording material by a heat from a heat generating element for producing heat by a magnetic flux generated by magnetic flux generating means, the apparatus including a magnetic flux confining member for confining a magnetic flux directing toward a predetermined region of the heat generating element from the magnetic flux generating means, and a first drive transmission member, provided at one end of the magnetic flux confining member, for transmitting rotational drive to the magnetic flux confining member and a second drive transmission member, provided at the other end of the magnetic flux confining member, for transmitting rotational drive to the magnetic flux confining member, the method comprising an adjusting step of adjusting such that first and second drive transmission members are supported by the magnetic flux confining member with a predetermined rotational position relation, using marks provided on the first and second

Abstract: A fixing device of an image forming apparatus of the present invention enables induction heating coils for a 100 V power source to set a ratio of inductance L to load resistance R of a heat roller to L/R <35×10?6 (H/?) and coil impedance Z (?) to Z<10 (?) and supplies a drive current at a high frequency of 40 to 70 kHz. By doing this, an eddy current generated in the heat roller is concentrated upon a metallic conductive layer by the skin effect and the heat generation efficiency of the heat roller is improved.

Abstract: A fixing device has a fixing belt, a trembler coil for heating the fixing belt with magnetic flux, a ferrite core around which the trembler coil is wound, and a heater for heating the ferrite core. The ferrite core has a Curie temperature which is between a fixing temperature of the fixing belt and a smoking start temperature of the fixing belt. The heating of the ferrite core with the heater allows the temperature of the ferrite core to reach the Curie temperature before the temperature of the fixing belt reaches a smoking start temperature. Thereby, an excessive rise in temperature of the fixing belt is suppressed, which prevents the fixing belt from smoking and igniting.

Abstract: A fixing device includes a heating roller which is made of a magnetic metal, a coil which is made of a plurality of twisted wires, an exciting circuit which applies a high-frequency current to the coil, and a core which is made of a heat resistant resin and is arranged inside the heating roller. The core has two grooves, each of the grooves being formed on a surface of the core and running along a longitudinal direction of the core. Parts of the coil are buried in the grooves such that a distance between the outer surface of the coil wound on the core and the inner surface of the heating roller is constant.

Abstract: A godet for guiding at least one advancing yarn in a yarn processing operation. The godet comprises a tubular casing which is mounted for free rotation on a support by means of a plurality of bearings. At least one of the bearings is a radially operative magnetic bearing, which comprises a rotating part and a stationary part attached to the support, with a bearing gap formed between the parts. The stationary part includes at least one pole element with an excitation winding, and the rotating part is made of at least one laminated component of a magnetizable material which is fixed on the inner side of the tubular casing. The pole element and the laminated component cooperate for guiding a magnetic flux.

Abstract: A fixation apparatus having a good fixability in its longitudinal direction and an image forming apparatus are provided. The fixation apparatus includes an electromagnetic induction heating member which is a hollow rotation member, and a magnetic flux generation member for causing the electromagnetic induction heating member to generate heat by generating magnetic flux in the electromagnetic induction heating member. The fixation apparatus fixes a toner image on a recording material by imparting heat energy by heat generation of the electromagnetic induction heating member to the recording material to be conveyed. The electromagnetic induction heating member has a different thickness in the longitudinal direction thereof and a uniform diameter at a surface facing the magnetic flux generation means in the longitudinal direction.

Abstract: A heating apparatus has an induction heat generation member for electromagnetic induction heat generation by the magnetic flux at a heating portion, wherein a material to be heated is introduced to the heating portion and is fed in direct contact with the induction heat generation member or in contact to a heat transfer material for receiving heat from the induction heat generation member; a magnetic flux adjusting unit for changing a distribution of a density of an effective magnetic flux actable on the induction heat generation member with respect to a widthwise direction perpendicular to a feeding direction of the material to be heated; wherein magnetic flux adjusting unit has a plurality of steps which extend in the feeding direction and are selectable to change the distribution of the magnetic flux density in response to a width of the material measured in the widthwise direction, wherein a step of the steps for a largest magnetic flux adjustment region measured in the widthwise direction is largest.

Abstract: An electromagnetic induction heating apparatus capable of uniformize a temperature distribution in a longitudinal direction of an induction heating member includes: an exciting coil (magnetic flux generation means); a fixation roller (induction heating member) for generating heat by electromagnetic induction heating by action of magnetic flux generated by the exciting coil the induction heating member heating a material to be heated through heat generation thereof by introducing the material to be heated into a heating portion and conveying the material to be heated in contact with the fixation roller; and magnetic flux shielding plate (magnetic flux adjusting means) for changing a distribution of a density of an effective magnetic flux which is the magnetic flux generated by the exciting coil and actable on the fixation roller, in a longitudinal direction of the heating portion perpendicular to a conveyance direction of the material to be heated.

Abstract: A heating apparatus, for heating a material P to be heated by heat from a heat generation member which has a predetermined curie temperature characteristic and generates heat by magnetic flux produced by a magnetic flux generation device. The apparatus includes a discrimination device for discriminating whether or not the curie temperature characteristic of the heat generation member is a predetermined characteristic and a control device for terminating the supply of electric power to the magnetic flux generation device when the discrimination device determines that the curie temperature characteristic is not the predetermined characteristic.

Abstract: A fusing station (100) for fusing toner to an image receiving medium (102) includes: a fuser roller (120) configured as a heat pipe including a sealed hollow cavity (124) containing a working fluid; a pressure roller (140) that forms a nip with the fuser roller (120) through which the image receiving medium (102) passes; and, an electrical coil (128) inductively coupled to the fuser roller (120) to inductively heat the fuser roller (120) upon energizing the electrical coil (128) with electrical power.

Abstract: An image forming apparatus has an image forming unit; a heating rotatable member; a magnetic flux generator for generating a magnetic flux for induction heat generation in the heating rotatable member; a controller for controlling a temperature of the heating rotatable member; a temperature detector for detecting a temperature of the heating rotatable member at a predetermined region; magnetic flux confinor for confining the magnetic flux from the magnetic flux generator in accordance with an output of the temperature detector; and a moving unit for movement the magnetic flux confinor between a magnetic-flux-confinement position and a n on-magnetic-flux-confinement position, wherein when the output of the temperature detector indicates a temperature outside a predetermined temperature range, an image forming operation is interrupted, and executes operation of the moving unit to move the magnetic flux confinor to the non-magnetic-flux-confinement position and restoring operation to restore the temperature of t

Abstract: To control a surface temperature of a heating element to be an appropriate fusing temperature, a fuser comprises a supporter having a core metal at least, a heating element supported by the supporter, a magnetic field generator for generating a magnetic field to render the heating element generate heat with induction heating, and a gap retainer disposed at the magnetic field generator, brought in contact with the supporter, for retaining a gap between the supporter and the magnetic field generator.

Abstract: A Fixing device has a heat roller, a magnetic flux generating element, and a magnetic flux block section. The magnetic flux block section for blocking magnetic flux flowing from a magnetic flux generating element to a heat roller is moved to a position at which the magnetic flux does not cause the heat roller to generate heat when rotation of the heat roller stops. The magnetic flux block section is moved to a position at which the heat roller generates heat when the heat roller rotates. Therefore, when rotation of the heat roller stops, even if electric current is applied to the magnetic flux generating element to generate magnetic flux from the magnetic flux generating element, heat generation by the magnetic flux generating element is prevented, so that smoking and firing of the heating element is suppressed.

Abstract: An image heating apparatus includes a heating rotatable member for heating an image on a recording material in a heating nip; a magnetic flux generator for generating a magnetic flux for induction heat generation in the heating rotatable member; a magnetic flux confining device for confining the magnetic flux directed toward a predetermined region of the heating rotatable member from the magnetic flux generator; and a moving device for repeatedly moving the magnetic flux confining device during a heating operation between the operating position and a retracted position retracted from the operation position, when the recording material which has a predetermined width overlapping with a part of the predetermined region is continuously heated by the apparatus.

Abstract: A fixing apparatus used in an image forming apparatus has a fixing member for fixing toner on paper and a pressure member making contact therewith to form in between a nip through which paper is passed. The fixing member has a support member formed of a ferromagnetic material and a heating layer formed adjacent thereto in the form of a thin layer of a non-magnetic, electrically conductive material. When a high-frequency electric current is passed through an exciting coil that is combined with the fixing member, the fixing member produces a high-frequency magnetic field, thereby produces induced eddy currents in the heating layer of the fixing member, thereby produces Joule's heat in the heating layer, and thereby heats the fixing member. A leaking magnetic flux is absorbed by the support member of the ferromagnetic member, and thus has reduced influence on metal parts located around the fixing apparatus.

Abstract: Disclosed herein is an induction heating type fusing device for fixing toner image on a transfer material. The fusing device includes an exciting coil that induces induction magnetic field by applying AC current; a hollow heating member installed near the exciting coil; multiple magnetic members mounted inside the heating member in the longitudinal direction; and a drive section that moves the multiple magnetic members in accordance with the width of transfer material to be fixed.

Abstract: The present invention provides a fixing device and a digital photocopier which can shorten the time from an instruction of starting image formation to end of fixing. The fixing device is provided in a cylinder made of metal and having a small thickness, and includes a magnetic excitation coil. When the power source is turned on, all the electric power defined by subtracting an electric power amount consumed by components other than the fixing device is supplied to the magnetic excitation coil to perform heating. As the structural components of the photocopier and auxiliary devices added to the photocopier operate, the electric power defined by subtracting, from the maximum input electric power, the electric power consumed by the structural components of the photocopier and the auxiliary devices is supplied to perform heating. In this manner, the heat roller of the fixing device is heated, in a short time, to a temperature which enables fixing, so that the time required for first copying can be shortened.

Abstract: An image heating apparatus for heating an image on a recording material by heat generation of a heating member includes a coil configured to generate a magnetic flux by energization a heat generation member having an electroconductive layer that generates heat by magnetic flux for heating an image on a recording material and, a frequency switching device for switching a frequency of a current supplied to the coil. The electroconductive layer includes a first electroconductive member at a central portion thereof and a second electroconductive member at an end portion thereof. The first electroconductive member has a resistence characteristic, with respect to the frequency of the current supplied to the coil, different from that of the second electroconductive member.

Abstract: An image heating apparatus has a magnetic flux generator for generating a magnetic flux; a heat generation member for generating heat by the magnetic flux generator; a magnetic flux adjustor for adjusting an effective magnetic flux region toward the heat generation member with respect to a widthwise direction which is perpendicular to a feeding direction of a material to be heated, wherein the material to be heated is heated by heat generation of the heat generation means; wherein the magnetic flux adjustor includes a magnetic flux adjusting member and moving member for moving the magnetic flux adjusting member, and wherein a temperature distribution in theat generation member with respect to the widthwise direction is adjusted by moving the flux adjusting member to a predetermined magnetic flux adjusting position by the moving member; and a discriminator for discriminating whether the effective magnetic flux region corresponds to a size of the material to be heated or not when the magnetic flux adjusting mem