JPH10106739A - Exciting coil, heater system and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce self-heating of a coil, reduce the cost, and improve energy efficiency by using it in a heater system by constituting an exciting coil of bundled wires of plural conductive wires which are insulated from each other and have a prescribed wire diameter. SOLUTION: A first member 1 and a pressure roller 6 to form a nip part N by being brought into pressure contact with this, are contained in a fixing device 100 in an electrophotographic printer or the like. The member 1 is composed of an exciting coil 3 and a cylindrical fixing film 2 or the like. B an alternating current from an exciting circuit 5, an alternating magnetic flux is generated in the coil 3 composed by winding plural bundled wires 3d composed of plural fine wires by performing heat resistant insulation covering on a conductor. Therefore, an electromagnetic induction heater layer of the film 2 is heated in the nip part N and its vicinity by the eddy current. Since a wire diameter ϕ1 of the conductor of the coil 3 is set to (ϕ1 <=δ) to an entering depth δ defined by δ=(πfμσ)<-1/2> , an increase in heating by a copper loss is restrained. In the expression, (f) is a frequency of an exciting current, and μis magnetic permeability of conductive wire rods, and δ is electric conductivity of the conductive wire rods.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exciting coil, a heating device of an electromagnetic (magnetic) induction heating type, and an image forming apparatus such as an electrophotographic apparatus and an electrostatic recording apparatus having the heating apparatus as an image heating apparatus. .

[0002]

2. Description of the Related Art For convenience, an image heating apparatus (fixing apparatus) provided in an image forming apparatus such as a copying machine, a printer, and a facsimile for heating and fixing a toner image on a recording material (image carrier) will be described as an example. .

In an image forming apparatus, a recording material (transfer material sheet, electrofax sheet, electrostatic recording paper, OHP sheet, or the like) is transferred to an appropriate image forming process means such as an electrophotographic process, an electrostatic recording process, or a magnetic recording process. An unfixed image (toner image) of the target image information formed and carried on a toner (heat-softening colored powder) made of a heat-meltable resin or the like in a transfer method or a direct method on printing paper or format paper. ) Has been widely used as a fixing device for heating and fixing an image to a surface of a recording material as a permanent fixed image. Recently, a film heating type apparatus has been put into practical use. Also, an electromagnetic induction heating system has been proposed.

A) Heat roller type fixing device This is a fixing device which basically has a pressure roller pair of a fixing roller (heating roller) and a pressure roller, and rotates the roller pair to form a mutual pressure contact portion between the roller pairs. A recording material having an unfixed toner image to be fixed in the fixing (heating) nip portion is introduced and held and transported. The unfixed toner image is formed by the heat of the fixing roller and the pressing force of the fixing nip portion. Is thermally and pressure-fixed to the surface of the recording material.

[0005] The fixing roller generally has a hollow metal roller made of aluminum as a base (core metal), and a halogen lamp as a heat source is inserted and disposed in the inner space thereof. The power supply to the halogen lamp is controlled to control the temperature so that the predetermined fixing temperature is maintained.

Particularly, as a fixing device of an image forming apparatus for forming a full-color image, which is required to have a capability of sufficiently heating and melting a maximum of four toner image layers to mix colors,
If not sufficiently heated to the interface between the recording material and the toner layer, a fixing failure occurs, so the core of the fixing roller has a high heat capacity, and the toner image is wrapped around the core and melted uniformly. A rubber elastic layer for
The toner image is heated via the rubber elastic layer. There is also a configuration in which a heat source is provided in the pressure roller so that the pressure roller is also heated and controlled in temperature.

However, the heat roller type fixing device has a large heat capacity even when the power of the image forming apparatus is turned on and the halogen lamp, which is the heat source of the fixing device, is energized at the same time. It takes a considerable waiting time (wait time) from the time when it is completely cold to when it rises to a predetermined fixing temperature, and lacks quick startability. In addition, it is necessary to keep the fixing roller in a predetermined temperature-controlled state by energizing the halogen lamp so that the image forming operation can be performed at any time even when the image forming apparatus is in a standby state (non-image output). There were problems such as a large amount.

A lamp using a halogen lamp as a heat source is once inefficient, because it converts energy into light.

In a fixing device or a pressure roller having a particularly large heat capacity, such as the fixing device of the above-described full-color image forming apparatus, a delay occurs between the temperature control and the temperature rise of the roller surface. Problems such as poor fixing, uneven gloss and offset have occurred.

B) Fixing device of film heating system A fixing device of film heating system is disclosed in, for example,
Japanese Patent Application Laid-Open No. 13182, Japanese Patent Application Laid-Open No. 2-1577878, Japanese Patent Application Laid-Open No. 4-44075, Japanese Patent Application Laid-Open No. 4-204980, and the like.

That is, a nip portion is formed by sandwiching a heat-resistant film (fixing film) between a ceramic heater as a heating element and a pressing roller as a pressing member. A recording material on which an unfixed toner image to be fixed is formed is carried between the pressure roller and the recording material. The recording material is sandwiched and conveyed together with the film. And fixing the unfixed toner image on the surface of the recording material with heat and pressure by the pressing force of the nip portion.

This film heating type fixing device can be constituted as an on-demand type device using a ceramic heater and a member having a low heat capacity as a film, and a ceramic heater as a heat source only when an image is formed by an image forming apparatus. To a state in which heat is generated to a predetermined fixing temperature, the waiting time from the power-on of the image forming apparatus to the image forming executable state is short (quick start property), and the power consumption during standby is greatly reduced. There are advantages such as small (power saving).

However, a full-color image forming apparatus requiring a large amount of heat or a fixing device for a high-speed model has a calorific point.

C) Fixing Device of Electromagnetic Induction Heating System JP-A-51-109737 discloses an induction heating fixing device in which an eddy current is generated in a fixing roller by magnetic flux and heat is generated by Joule heat. This makes it possible to directly generate heat in the fixing roller by utilizing the generation of an induced current, and achieves a more efficient fixing process than a heat roller type fixing device using a halogen lamp as a heat source.

[0015]

SUMMARY OF THE INVENTION The present invention relates to an improvement in an electromagnetic induction heating system among various heating systems known in the art as described above.

In the fixing device of the electromagnetic induction heating type disclosed in Japanese Utility Model Laid-Open Publication No. 51-109737, the energy of the alternating magnetic flux generated from the exciting coil as the magnetic field generating means is used to raise the temperature of the entire fixing roller. Therefore, there is a drawback that heat radiation loss is large, the density of fixing energy with respect to the input energy is low, and the efficiency is poor.

Therefore, in order to obtain the energy acting on the fixing at a high density, the excitation coil is brought closer to the fixing roller as the heating element, or the distribution of the excitation coil is concentrated near the fixing nip portion, thereby achieving high efficiency. A fusing device was devised.

However, a new problem has arisen in the above fixing device. That is,. The excitation coil is indirectly heated because the excitation coil is close to the fixing nip portion or the heat generating portion.

[0019] Since the distribution of the exciting coil is concentrated in the nip portion or the heat generating portion where the strong magnetic field is formed, the copper loss of the exciting coil itself increases and self-heating easily occurs.

As a result, there has been a problem that a conductive wire having higher heat resistance than that of the conventional conductive wire is required to constitute the exciting coil, which is expensive.

An object of the present invention is to provide an electromagnetic induction heating type heating device which can reduce the heat generated by the exciting coil itself as a magnetic field generating means, and can use a low-grade bundled wire, thereby making it possible to use an inexpensive exciting coil or the exciting coil. Providing an electromagnetic induction heating type heating device using a coil, enabling efficient use of input power and improving the heat generation efficiency of the device, reducing power consumption and shortening the wait time (quick start property). In an image heating apparatus of an image forming apparatus, an apparatus capable of maintaining high image quality even for an image having a large amount of toner such as a full-color image and capable of coping with high speed is provided at a low cost. It is in.

[0022]

According to the present invention, there is provided an exciting coil, a heating device and an image forming apparatus having the following constitutions.

(1) It is configured by winding a bundle of a plurality of conductive wires insulated from each other, and δ = (πfμσ)
Penetration depth δ defined by ^-1/2 (f is the frequency of the exciting current,
(μ is the magnetic permeability of the conductive wire, and σ is the conductivity of the conductive wire), wherein the wire diameter φ ₁ of the conductive wire is φ ₁ ≦ δ.

(2) An electromagnetic induction heat-generating member and a magnetic field generating means for generating heat by applying a magnetic field to the electromagnetic induction heat-generating member, and applying heat energy to the material to be heated by the heat generated by the electromagnetic induction heat-generating member. A heating device, wherein the magnetic field generating means includes an exciting coil for generating an alternating magnetic field, and the exciting coil is configured by winding a bundle of a plurality of conductive wires insulated from each other, and δ = (πfμσ) Penetration depth δ defined by ^-1/2 (f is the frequency of the exciting current, μ is the permeability of the conductive wire,
σ For the conductivity of the conductive wire material), heating apparatus, wherein a wire diameter phi ₁ of the conductive wire was φ ₁ ≦ δ.

(3) An electromagnetic induction heating member, a first member having a magnetic field generating means for generating a magnetic field by applying a magnetic field to the electromagnetic induction heating member, and mutually press-contacting the first member directly or with another member interposed therebetween. Having a second member forming a nip portion,
A heating device for applying heat energy to the material to be heated held and conveyed by the nip portion by the heat generated by the electromagnetic induction heating member,
The magnetic field generating means includes an exciting coil for generating an alternating magnetic field, and the exciting coil is configured by winding a bundle of a plurality of conductive wires insulated from each other, and δ = (πfμσ) ^−1/2 . For the defined penetration depth δ (f is the frequency of the exciting current, μ is the magnetic permeability of the conductive wire, and σ is the conductivity of the conductive wire),
Heating apparatus, wherein a wire diameter phi ₁ of the conductive wire was φ ₁ ≦ δ.

(4) The heating device according to (2) or (3), wherein the electromagnetic induction heating member is a rotating member or a traveling member.

(5) The heating device according to (2) or (3), wherein the electromagnetic induction heating member is a fixed member.

(6) In the heating device according to the item (3), the electromagnetic induction heating member is a rotating endless film member or a running end film member, and the second member from the inside which is the first member side. A heating apparatus comprising: a laminated body including at least an electromagnetic induction heating layer, an elastic layer, and a release layer in that order on an outer side which is a member side.

(7) In the heating device according to the above (3), the electromagnetic induction heating member is a rotating endless film member or a traveling end film member, and the second member from the inside which is the first member side. A heating device, which is a laminated body including at least a heat insulating layer, an electromagnetic induction heating layer, an elastic layer, and a release layer in that order on the outer side which is a member side.

(8) In the heating device according to the above (3), the electromagnetic induction heating member is a rotating endless film member or a running end film member, and the second member is formed from the inside which is the first member side. A heating device comprising: a laminate comprising at least an electromagnetic induction heating layer and a release layer in that order on the outer side, which is a member side.

(9) In the heating device according to the item (3), the electromagnetic induction heating member is a rotating endless film member or a running endless film member, and the second member from the inside which is the first member side. A heating device comprising: a laminated body including at least a heat insulating layer, an electromagnetic induction heating layer, and a release layer on an outer side which is a member side.

(10) The heating device according to any one of (3) to (9), wherein the second member is a rotary pressing member.

(11) In the heating device according to (3), the second member is a rotary pressing member, the electromagnetic induction heating member is a rotating member or a traveling member, and the electromagnetically driven member is rotated by the second member. A heating device, wherein the induction heating member is rotated or run.

(12) In the heating device according to the above (3), the electromagnetic induction heating member is a fixed member, and the fixed electromagnetic induction heating member and the second member are mutually pressed by a heat-resistant film. A nip portion formed by the heating device.

(13) The heating device according to (12), wherein the material to be heated is sandwiched and conveyed between the heat-resistant film in the nip portion and the second member.

(14) The heating device according to (12) or (13), wherein the second member is a rotary pressing member.

(15) In the heating device according to (12) or (13), the second member is a rotary pressing member, the heat-resistant film is a rotating member or a traveling member, and the second member is driven to rotate. A heating device characterized in that the heat-resistant film is rotated or run by the heating device.

(16) In the heating device according to any one of the above (12) to (15), the heat-resistant film is at least heat-resistant in order from the inside on the first member side to the outside on the second member side. A heating device, which is a laminate including a resin layer and a release layer.

(17) In the heating device according to (3) or (16), the center of gravity of the exciting coil is closer to the nip portion than the center of rotation of the rotating electromagnetic induction heating member or the rotating heat resistant member. A heating device.

(18) In the heating device according to any one of (2) to (17), the material to be heated is an image carrier on which an image is formed and carried, and the device heat-treats the image. A heating device, which is an image heating device.

(19) The heating device according to (18), wherein the image heating process is a process of fixing the image to the image carrier.

(20) An image forming means for forming an image on the image carrier and an image heating device for heating the image formed on the image carrier are provided, wherein the image heating device comprises (2) to (1)
An image forming apparatus, which is the heating apparatus according to any one of 7).

(21) The image forming apparatus according to (20), wherein the image heating process is a process of fixing the image to the image carrier.

<Operation> 1) Regarding the exciting coil, δ = (πfμ) as described above.
σ) For the penetration depth δ defined by ^-1/2 , the wire diameter φ ₁ of the conductive wire (thin wire) forming the excitation coil is selected by selecting a wire diameter satisfying φ ₁ ≦ δ as described later. It is possible to use a bundle of low heat-resistant grade by reducing the heat generated by the exciting coil itself, and to provide an inexpensive exciting coil, and therefore an inexpensive electromagnetic induction heating type heating device using the exciting coil as a magnetic field generating means. be able to.

2) Electromagnetic induction heating type heating device using the exciting coil as a magnetic field generating means The center of gravity of the exciting coil is brought closer to the nip from the center of rotation of the rotating electromagnetic induction heating member or the rotating heat resistant member. Thereby, in addition to the features and effects of the above 1), the energy of the alternating magnetic flux generated by the exciting coil can be efficiently consumed by the electromagnetic induction heating member, and the temperature of the electromagnetic induction heating member can be increased quickly. Energy consumption can be saved.

3) Therefore, the magnetic flux distribution is concentrated in the nip portion for heating the material to be heated by sandwiching and transporting the material to be heated between the first member and the second member, and in the vicinity thereof, the magnetic flux distribution is concentrated. The magnetic flux can be efficiently supplied to the electromagnetically induced heat-generating members, thereby improving the heat generation efficiency of the device. Low power consumption (power saving), shortening of wait time is possible. It is possible to heat the material to be heated quickly and sufficiently. In an image heating device of an image forming apparatus, a toner image can be sufficiently melted even for an image having a large amount of toner such as a full-color image. The effects such as quick start property and high speed processing property can be obtained while maintaining high image quality fixing ability.

[0047]

BEST MODE FOR CARRYING OUT THE INVENTION

<First Embodiment> (FIGS. 1 to 6) (1) Example of Image Forming Apparatus FIG. 1 is a schematic configuration diagram of an example of an image forming apparatus. The image forming apparatus of this example is an electrophotographic color printer.

Reference numeral 101 denotes an electrophotographic photosensitive drum (image carrier) made of an organic photosensitive member or an amorphous silicon photosensitive member, and is rotated at a predetermined process speed (peripheral speed) in a counterclockwise direction indicated by an arrow.

The photosensitive drum 101 undergoes a uniform charging process of a predetermined polarity and potential by a charging device 102 such as a charging roller during its rotation.

Next, the charged surface is subjected to a scanning exposure process of target image information by a laser beam 103 output from a laser optical box (laser scanner) 110. The laser optical box 110 outputs laser light 103 modulated (on / off) in response to a time-series electric digital pixel signal of target image information from an image signal generator such as an image reader (not shown), and The scanning exposure is performed on the drum surface.
An electrostatic latent image corresponding to the target image information scanned and exposed on the surface is formed. A mirror 109 deflects an output laser beam from the laser optical box 110 to an exposure position on the photosensitive drum 101.

In the case of forming a full-color image, scanning exposure and latent image formation are performed on a first color-separated component image of a target full-color image, for example, a yellow component image. Is developed as a yellow toner image by the operation of the yellow developing device 104Y. The yellow toner image is transferred to the surface of the intermediate transfer drum 105 at a primary transfer portion T1, which is a contact portion (or a close portion) between the photosensitive drum 101 and the intermediate transfer drum 105. After the transfer of the toner image to the surface of the intermediate transfer drum 105, the surface of the rotating photosensitive drum 101 is
7 removes adhered residues such as transfer residual toner and is cleaned.

The process cycle of charging, scanning exposure, development, primary transfer, and cleaning as described above performs the second color separation component image (for example, magenta component image, magenta developing unit 104M operates) of the target full-color image, Third color separation component image (for example, cyan component image, cyan developing device 104C
Operates), a fourth color separation component image (for example, a black component image,
(The black developing device 104BK is activated) for each color separation component image, and the toner images of four colors of a yellow toner image, a magenta toner image, a cyan toner image, and a black toner image are sequentially superimposed on the surface of the intermediate transfer drum 105. Is transferred to form a color toner image corresponding to the desired full-color image.

In the present embodiment, the toner containing a low softening substance is used.

The intermediate transfer drum 105 has a medium resistance elastic layer and a high resistance surface layer on a metal drum, and is in contact with or close to the photosensitive drum 101.
It is driven to rotate clockwise as indicated by the arrow at approximately the same peripheral speed as 01,
A bias potential is applied to the metal drum of the intermediate transfer drum 105, and the potential difference between
The toner image on the side 01 is transferred to the surface of the intermediate transfer drum 105.

The color toner image synthesized and formed on the surface of the rotary intermediate transfer drum 105 is transferred to the secondary transfer portion T2 which is a contact nip portion between the rotary intermediate transfer drum 105 and the transfer roller 106. The image is transferred onto the surface of the recording material (image carrier) P sent from the paper supply unit (not shown) to the transfer unit T2 at a predetermined timing. Transfer roller 1
Reference numeral 06 supplies a charge having a polarity opposite to that of the toner from the rear surface of the recording material P, and collectively transfers the combined color toner images sequentially from the surface of the intermediate transfer drum 105 to the recording material P.

The recording material P that has passed through the secondary transfer portion T2 is separated from the surface of the intermediate transfer drum 105, introduced into the image heating device (fixing device) 100, and subjected to the heat fixing process of the unfixed toner image. The sheet is discharged to a discharge tray (not shown) outside the apparatus as a color image formed product. The fixing device 100 is an electromagnetic induction heating type heating device. The fixing device 100 will be described in detail in the following section (2).

After the transfer of the color toner image to the recording material P, the rotating intermediate transfer drum 105 is cleaned by the cleaner 108 by removing the adhered residue such as untransferred toner and paper dust. The cleaner 108 is normally kept in a non-contact state with the intermediate transfer drum 105, and is kept in contact with the intermediate transfer drum 105 in the process of performing the secondary transfer of the color toner image from the intermediate transfer drum 105 to the recording material P. Is held.

The transfer roller 106 is always kept in a non-contact state with the intermediate transfer drum 105, and during the secondary transfer of the color toner image from the intermediate transfer drum 105 to the recording material P, the intermediate transfer drum 105
Is kept in contact with the recording material P via the recording material P.

A print mode for a mono-color image such as a black-and-white image can also be executed. Also, a double-sided image print mode or a multiple image print mode can be executed.

In the case of the double-sided image print mode, the recording material P on which the first-side image has been printed out of the fixing device 100 is turned upside down via a recirculation transport mechanism (not shown) and is sent to the secondary transfer portion T2 again. Then, the toner image is transferred to the two surfaces, and the toner image is again introduced into the fixing device 100 and subjected to the fixing process of the toner image to the two surfaces, whereby a double-sided image print is output.

In the case of the multiple image print mode, the recording material P on which the first image has been printed out of the fixing device 100 is not turned upside down via a recirculation transport mechanism (not shown) to the secondary transfer portion T2 again. The multi-image print is output by receiving the second transfer of the toner image on the surface on which the first image print has been performed and then re-introduced to the fixing device 100 to undergo the second toner image fixing process.

(2) Fixing Apparatus 100 A) Overall Schematic Configuration of Apparatus FIG. 2 is a schematic cross-sectional view of a main part of an electromagnetic induction heating type fixing apparatus 100 of this embodiment.

Reference numeral 1 denotes a first member having an electromagnetic induction heating member 2 and a magnetic field generating means 3 for applying a magnetic field to the electromagnetic induction heating member to generate heat, and 6 denotes a nip portion N Is a pressure roller as a second member that forms

In the case of the device of the present embodiment, the electromagnetic induction heating member 2 is a cylindrical film (endless film member, rotary heating member) including an electromagnetic induction heating layer (conductor layer, magnetic layer, resistor layer). Hereinafter, it is referred to as a fixing film. The layer structure of the fixing film 2 will be described in detail in section B).

The cylindrical fixing film 1 is loosely fitted to a cylindrical horizontally long film guide member 4. The film guide member 4 has a substantially cylindrical body formed by superposing lower and upper cross-sectionally semicircular trough-shaped forming members 4a and 4b on both sides 4a and 4b. The film guide member 4 serves to support the cylindrical fixing film 2 and to improve the conveyance stability when the fixing film rotates. The lower film guide member 4a functions to press the nip portion N and support the exciting coil 3 as a magnetic field generating means, and is an insulating member that does not hinder the passage of magnetic flux. The material with the following is used. For example, phenol resin, fluorine resin, polyimide resin, polyamide resin, polyamide imide resin, PEEK resin, PES resin, PP
S resin, PFA resin, PTFE resin, FEP resin, LC
P resin or the like is preferably selected. The upper film guide member 4b can be made of the same material. The upper film guide member 4b may be omitted in device configuration.

The magnetic field generating means 3 is an exciting coil formed by winding a bundle 3d of an insulated coated conductive wire into a predetermined shape a plurality of times, as described in detail in section C) below. Reference numeral 3 denotes a boat-like shape substantially corresponding to the inner surface shape of the lower film guide member 4a, which is disposed and supported inside the lower film guide member 4a.

An assembly including the fixing film 2, the excitation coil 3, and the film guide member 4 is a first member,
This is referred to as "heating assembly" for convenience.

The pressure roller 6 as the second member is an elastic pressure roller in this embodiment. The pressure roller 6 is a silicone rubber coated with a core metal 6a and a roller, for example, with a thickness of 2 mm concentrically and integrally around the core metal. The pressure roller 6 is composed of a heat-resistant elastic material layer 6b made of fluoro rubber, fluoro resin, or the like. It is arranged so that it can be freely rotated and held between the chassis side plates.

The above-described heating assembly is disposed above the pressure roller 6 with the lower film guide member 4a facing downward, and a pressing force is applied by a biasing means such as a stay and a pressure spring (not shown). And the lower film guide member 4a
Is pressed against the upper surface of the pressure roller 6 with the fixing film 2 interposed therebetween, thereby forming a nip portion N.

The pressure roller 6 is driven by the driving means M to rotate counterclockwise as indicated by the arrow. A rotational force acts on the fixing film 2 due to a frictional force between the pressing roller 6 and the outer surface of the fixing film 2 due to the rotational driving of the pressing roller 6, and the inner surface of the fixing film 2 is lower at the nip portion N. The outer periphery of the film guide member 4 is rotated in a clockwise direction indicated by an arrow at a peripheral speed substantially corresponding to the rotational peripheral speed of the pressure roller 6 while sliding in close contact with the lower surface of the film guide member 4a (the pressure roller). Drive system).

In order to reduce the mutual sliding friction between the lower surface of the lower film guide member 4a and the inner surface of the fixing film 2 in the nip portion N, the lower surface of the lower film guide member 4a of the fixing nip portion N and the fixing film 2 A lubricant such as heat-resistant grease may be interposed between the inner surface of the lower film guide member 4a and the lower surface of the lower film guide member 4a.

An exciting circuit 5 is connected to the exciting coil 3. The excitation circuit 5 has a frequency of 20 kHz to 500 kHz.
z] can be generated by a switching power supply. In this example, an alternating current of 80 [kHz] can be supplied to the exciting coil 3.

The exciting coil 3 generates an alternating magnetic flux by an alternating current (high-frequency current) supplied from the exciting circuit 5.
The alternating magnetic flux is intensively distributed in the nip portion N and its vicinity, and mainly generates an eddy current in the electromagnetic induction heating layer of the fixing film 2 in the nip portion N and its vicinity. This eddy current generates Joule heat (eddy current loss) in the electromagnetic induction heating layer due to the specific resistance of the electromagnetic induction heating layer. That is, the fixing film 2 generates electromagnetic induction heat. The heat generated by the electromagnetic induction of the fixing film 2 is generated in the nip portion N where the alternating magnetic flux is concentrated.
And the nip N is heated in a highly efficient manner in the vicinity thereof. The temperature of the nip portion N is controlled such that a predetermined temperature is maintained by controlling the current supply to the exciting coil 3 by a temperature control system including a temperature detection unit (not shown).

Thus, the pressure roller 6 is driven to rotate, and the cylindrical fixing film 2 rotates around the film guide member 4 in accordance with the rotation, and power is supplied from the excitation circuit 5 to the excitation coil 3 as described above. When the nip portion N rises to a predetermined temperature and the temperature is controlled by the electromagnetic induction heating of the fixing film 2, the recording material P on which the unfixed toner image t conveyed from the image forming unit is formed. The image surface is introduced between the fixing film 2 in the nip portion N and the pressure roller 6 so as to face upward, that is, opposed to the fixing film surface. The nip portion N is conveyed together with the nip portion N. In the process in which the recording material P is nipped and conveyed in the nip portion N together with the fixing film 2, the unfixed toner image t on the recording material P is heated and fixed by heating by the electromagnetic induction heat of the fixing film 2. . After passing through the nip N, the recording material P is separated from the outer surface of the rotary fixing film 2 and is discharged and conveyed. After passing through the nip portion, the heat-fixed toner image on the recording material is cooled and becomes a permanent fixed image.

In this example, since a toner containing a low softening substance was used in the toner t, an oil application mechanism for preventing offset was not provided in the fixing device, but a toner not containing a low softening substance was used. In this case, an oil application mechanism may be provided. Further, a cooling section may be provided after the fixing nip to perform cooling separation. Also, when a toner containing a low softening substance is used, oil application or cooling separation may be performed.

B) Fixing Film 2 FIGS. 3A and 3B are schematic diagrams of the layer structure of the fixing film 2 as an electromagnetic induction heating member in this example.

The fixing film 2 of (a) is composed of a heat generating layer 2a made of a metal film or the like serving as a base layer of the electromagnetic induction heat generating fixing film, an elastic layer 2b laminated on its outer surface, and further laminated on its outer surface. It has a three-layer composite structure of the release layer 2c. In this cylindrical fixing film 2, the heat generating layer 2a
Is the inner surface side, and the release layer 2c is the outer surface side. As described above, when the alternating magnetic flux a acts on the heat generating layer 2a, an eddy current b is generated in the heat generating layer 2a, and the heat generating layer 2a generates heat. The heat heats the nip portion N via the elastic layer 2b and the release layer 2c, and heats the recording material as the material to be passed through the nip portion N to heat and fix the toner image. .

In the fixing film 2 of this embodiment, the surface of a 50 μm thick heat generating layer 2a made of nickel, which is a resistor, is covered with an elastic layer 2b made of silicone rubber, and further covered with a release layer 2c made of fluororesin. is there.

[0079] Heating layer 2a Heating layer 1 is made of 10 ^-5 to 10 ^-10 Ω · c in addition to nickel.
It is sufficient to use a metal, a metal compound, or an organic conductor that is a good electric conductor of m, and more preferably, a pure metal such as iron or cobalt having high magnetic permeability and exhibiting ferromagnetism or a compound thereof can be used.

If the thickness of the heat generating layer 2a is reduced, a sufficient magnetic path cannot be secured, and the magnetic flux may leak to the outside to reduce the heat generation energy of the heat generating element itself. Time tends to be longer.

Therefore, the thickness depends on the specific heat, density,
There are appropriate values depending on the values of magnetic permeability and resistivity. In this example, 1
A heating rate of 3 ° C./sec or more could be obtained in the thickness range of 0 to 100 μm.

[0082] Elastic Layer 2b The elastic layer 2b is made of silicone rubber, fluorine rubber, fluorosilicone rubber, or the like, and has good heat resistance and good thermal conductivity.

The thickness of the elastic layer 2b is 10 to 500 [μm].
Is preferred. When a color image is printed, a solid image is formed over a large area on the recording material P, especially for a photographic image. In this case, if the heating surface (the release layer 2c) cannot follow the unevenness of the recording material or the unevenness of the toner layer, uneven heating occurs, and gloss unevenness occurs in an image in a portion having a large amount of heat transfer and a portion having a small amount of heat transfer. The glossiness is high in a portion having a large amount of heat transfer, and low in a portion having a small amount of heat transfer. Elastic layer 2b
When the thickness is less than 10 [μm], the unevenness of the recording material or the toner layer cannot be completely followed, and uneven image gloss occurs. On the other hand, when the thickness is 1000 [μm] or more, the thermal resistance of the elastic layer 2b increases, and it is difficult to realize a quick start. More preferably, the thickness of the elastic layer 2b is preferably 50 to 500 [μm].

If the hardness of the elastic layer 2b is too high, the elasticity of the elastic layer 2b cannot follow the irregularities of the recording material or the toner layer, resulting in uneven image gloss. Therefore, the hardness of the elastic layer 2b is preferably 60 ° (JIS-A) or less, more preferably 45 ° or less.

The thermal conductivity λ of the elastic layer 2 b is 6 × 10 ⁻⁴ to 2 × 10 ⁻³ [cal / cm · sec · de].
g. ] Is good.

The thermal conductivity λ is 6 × 10 ⁻⁴ [cal / cm ·
sec deg. ], The thermal resistance is large, and the temperature rise in the surface layer (release layer 2c) of the fixing film 2 becomes slow.

The thermal conductivity λ is 2 × 10 ⁻³ [cal / cm ·
sec deg. ], The hardness becomes too high and the compression set becomes worse.

Therefore, the thermal conductivity λ of the elastic layer 2b is 6 ×
10 ^{-4 to} 2 × 10 ^-3 [cal / cm · sec · de
g. ] Is good. More preferably, 8 × 10 ^{−4 to} 1.5 ×
10 ⁻³ [cal / cm · sec · deg. ] Is good.

[0089] Release Layer 2c As the release layer 2c, a material having good releasability and heat resistance such as silicone resin, silicone rubber, fluorine rubber, and silicone rubber can be selected in addition to fluororesin such as PFA, PTFE, and FEP. .

The thickness of the release layer 2c is 20 to 100 [μm].
If the thickness is less than 20 [μm], there arises a problem that a portion having poor releasability is formed due to coating unevenness of the coating film and durability is insufficient. On the other hand, if it exceeds 100 [μm], the problem that the heat conduction is deteriorated occurs. In particular, in the case of a resin-based release layer, the hardness becomes too high, and the effect of the elastic layer 2b is lost.

As shown in FIG. 3B, in the layer structure of the fixing film 2, a heat insulating layer 2d is provided on the free surface side of the heat generating layer 2a (the side opposite to the elastic layer 2b side of the heat generating layer 2a). It may be provided.

As the heat insulating layer 2d, a fluororesin, a polyimide resin, a polyamide resin, a polyamideimide resin, P
EEK resin, PES resin, PPS resin, PFA resin, P
A heat-resistant resin such as TFE resin or FEP resin is preferable.

The thickness of the heat insulating layer 2d is 10 to 1
000 [μm] is preferable. The thickness of the heat insulating layer 2d is 10
When it is smaller than [μm], the heat insulating effect is small and the durability is insufficient. On the other hand, if it exceeds 1000 [μm], the distance between the exciting coil 3 and the heat generating layer 2a increases,
The magnetic flux is not sufficiently absorbed by the heating layer 2a.

When the heat insulating layer 2d is provided, it is possible to prevent the temperature of the exciting coil 3 from rising due to the heat generated in the heat generating layer 2a.
Stable heating can be performed.

C) Excitation Coil 3 The excitation coil 3 as the magnetic field generating means must generate an alternating magnetic flux sufficient for heating, but for that purpose, it is necessary to reduce the resistance component and increase the inductance component.

In the present embodiment, as the electric wire constituting the coil (wire loop) of the exciting coil 3, as shown in a model diagram in FIG.
Those wire diameter phi ₁ as core (conductive wire material) 3a is for high frequency which is a plurality of bundled diameter phi ₂ and the thin line 3c which has been subjected to heat-resistant insulating coating 3b to bundled wires 3d which was 3mm copper wire of 0.2mm This boat 3d is wound five times around the nip N to form a boat-shaped exciting coil 3. In particular, in the apparatus of the present embodiment, the generated magnetic field can be passed in a desired heating area of the heat generating layer 2a of the fixing film 2 by distributing the exciting coil 3 in a concentrated manner in the vicinity of the nip portion. The device can be realized.

FIG. 5 shows the wire diameter φ _{1 of} each of the insulated copper thin wires 3c constituting the bundle 3d constituting the coil of the exciting coil 3 (the wire diameter here refers to the diameter of the core wire (conductive wire material) 3a). And the self-heating value Q.
Cross-sectional area of a graph of measurement of the amount of heat generated when driven with a constant current of frequency f at 80kHz by adjusting the number of wire diameter phi ₁ of the thin line to be the same.

As the wire diameter φ _{1 of the} thin wire becomes thicker, the calorific value of the exciting coil 3 itself increases. Broken line in the drawing is the wire diameter phi ₁ of the thin line in theoretical value δ = (πfμσ) is the penetration depth defined by ^-1/2 [delta] (approximately in the case of copper / 80 kHz 0.23 mm)
It is shown that the heat generation curve rises from about twice as large as the above, and the copper loss increases. On the other hand, the plot in the figure is an actually measured value, and it can be seen that the copper loss increases from a wire diameter that is about half the theoretical value. According to this result, the conventional thin wire of φ ₁ = 2δ generates 1.3 times more heat than the DC copper loss Q ₀ .

Further, in order to verify these, the frequency f
The relationship shown in FIG. 6 was confirmed by examining the boundary line diameter φ ₀ of the thin wire where the self-heating of the exciting coil starts to increase using the parameter as a parameter. Such a phenomenon is considered to be caused by the fact that the excitation coil 3 is concentrated near the nip portion N as in this example, and the symmetry is lost. It is expected that a concentrated current flows in a range thinner than the depth δ. In such a case, it is possible to suppress the self-heating of the exciting coil 3 and to heat the fixing film 2 with a small loss by reducing the wire diameter φ ₁ to such a small value that heat generation due to copper loss does not increase. Become.

In this example, from the above results, the diameter of the fine wire φ ₁
Is set to less than half the thickness 2δ which is twice the penetration depth δ normally required. As 0.2 wire diameter phi ₁ of the thin line in particular, by using the bundled wires 3d bundling 98 present this as wires for constituting the coil (Senwa) of the exciting coil 3, a small excitation coil extremely self-heating 3 has been achieved.

<Second Embodiment> (FIG. 7) FIG. 7 is a schematic cross-sectional view of a fixing device 100 as an electromagnetic induction heating type heating device according to a second embodiment. The apparatus of this embodiment is different from the fixing apparatus of the first embodiment in that a ferrite core 3e as an exciting iron core for guiding the alternating magnetic flux generated by the exciting coil 3 to the fixing film 1 is further provided. The ferrite core 3e is located at the center of the exciting coil 3 and supported by the lower film guide member 4a. The lower surface of the ferrite core 3e corresponds to the nip portion N. The other configuration of the device is the same as that of the fixing device 100 of the first embodiment. Therefore, the same reference numerals are given to the common constituent members and portions, and the description will not be repeated.

In this embodiment, by adding the ferrite core 3e, the magnetic flux generated by the exciting coil 3 is guided to the fixing film 2 to obtain high efficiency.

Although the ferrite core 3e has a very high magnetic permeability, it is known that it has a lower Curie point than a ferromagnetic metal, so care must be taken when using it at high temperatures. That is, at room temperature, the excitation coil 3 viewed from the excitation circuit 5 has a high inductance due to the high magnetic permeability of the ferrite core 3e, but the inductance decreases at a high temperature at which the temperature of the ferrite core 3e exceeds the Curie point, and the excitation decreases. The load of the circuit 5 may suddenly change, which may cause a failure. Therefore, when using the ferrite core 3e, it is necessary to take care not to heat the ferrite core 3e.

[0104] The use of a wire bundle 3d as wires for constituting the coil (Senwa) of the exciting coil 3 in the present embodiment, is set lower than the penetration depth δ as wire diameter phi ₁ of fine wire constituting the wire bundle 3d, By realizing the exciting coil 3 with small self-heating, the temperature rise of the adjacent ferrite core 3e is suppressed.

<Third Embodiment> (FIG. 8) The electromagnetic induction heat-generating member may be a device having a fixed member. FIG. 8 shows an example.

Reference numeral 2A denotes an electromagnetic induction-generating, horizontally long plate member (a heating plate such as an iron plate) fixed and disposed on the lower surface of the lower film guide member 4a of the heating assembly as the first member. The fixed electromagnetic induction heating member 2A and the pressure roller 6 as the second member are fixed to a heat-resistant thin fixing film F.
To form a nip portion N.

The exciting coil 3 is wound around a ferrite core 3e having a cross section gate shape (downward U-shape), and the ferrite core 3e is disposed above the heat generating plate 2A inside the lower film guide member 4a.

The fixing film F is a thin cylindrical low-heat-capacity film member (rotary heating member) composed of a heat-resistant base film (support layer) such as a polyimide resin and a release layer formed on the outer peripheral surface thereof. Is loosely fitted to the cylindrical film guide member 4. The fixing film F itself has no electromagnetic induction heat generation.

The fixing film F rotates while rotating the nip portion N in close contact with the lower surface of the electromagnetic induction heating member 2A whose inner surface is fixed by the rotation of the pressing roller 6 (the pressing roller driving system). ).

The fixed electromagnetic induction heat-generating member 2A intensively receives the alternating magnetic flux generated by the application of the alternating current to the exciting coil 3 of the heating assembly by the ferrite core 3e and generates electromagnetic induction heat.

Then, the recording material P is introduced between the fixing film F in the nip portion N and the pressure roller 6, and the fixing film F
In the process of nipping and transporting the nip portion N together with the toner image t, the heat generated by the fixed electromagnetic induction heating member 2A is received via the fixing film F and is heated.
Is established.

In this embodiment, the fixing film F has no electromagnetic induction heating layer, so that the structure is inexpensive. Also, since the fixing film F is rich in flexibility, the diameter of the fixing film F can be reduced and the apparatus can be easily downsized. .

What is important in making the above characteristics effective is the magnitude of the self-heating of the exciting coil 3. In other words, as the size of the coil is reduced, the clearance between the exciting coil 3 and other supporting members is reduced, so that heat is easily trapped.
It is necessary to prevent the temperature of the ferrite core 3e from rising more than in the device of the embodiment, and it is essential to suppress the self-heating of the exciting coil 3e.

In this embodiment, in order to establish the above-described system, the diameter of the thin wire constituting the bundle of the exciting coil 3 is set to a wire diameter φ ₁ of not more than the penetration depth δ, and the self-heating of the exciting coil 201 is suppressed. Thus, a compact image heating apparatus is realized. In order to establish a system as described above in this example, using a wire bundle 3d as wires for constituting the coil (Senwa) of the exciting coil 3, the depth penetration as wire diameter phi ₁ of fine wire constituting the wire bundle 3d The value is set to δ or less, and the self-heating of the exciting coil 3 is suppressed, thereby realizing a small-sized image heating apparatus.

The layer structure of the fixing film F is not limited to the above example, but may be another layer structure such as an elastic layer interposed between the heat-resistant base film and the release layer.

<Fourth Embodiment> (FIG. 9) The configuration of the fixing device 100 is not limited to the pressure roller driving system of the above-described embodiment.

For example, as shown in FIG. 9A, between a film guide member 4 of a heating assembly as a first member composed of a film guide member 4, an exciting coil 3, and the like, a driving roller 7, and a tension roller 8. Then, an endless belt-shaped fixing film 2 of electromagnetic induction heat is suspended and stretched, and the lower surface of the film guide member 4 of the heating assembly and the driven rotary pressing roller 6 as a second member are sandwiched between the fixing film 2. To form a nip N by pressing the fixing film 2 with the driving roller 7 to rotate the fixing film 2.

In the apparatus (b), the endless belt-shaped fixing film 2 of electromagnetic induction heat is suspended and stretched between the film guide member 4 and the driving roller 7 of the heating assembly. The apparatus is configured such that the lower surface of the member 4 and a driven rotary pressure roller 6 as a pressure member are pressed against each other with the fixing film 2 interposed therebetween to form a nip portion N, and the fixing film 2 is rotationally driven by a driving roller 7. .

The device (c) is a long web-like member in which the fixing film 2 having electromagnetic induction and heat is wound into a roll.
This is locked from the feeding shaft 10 side to the winding shaft 9 side via the lower surface of the film guide member 4 of the heating assembly, and the lower surface portion of the film guide member 4 of the heating assembly and the driven rotary press as a pressing member. The roller 6 is brought into pressure contact with the fixing film 2 interposed therebetween to form a nip portion N, and the fixing film 2 is wound and moved at a predetermined speed from the unwinding shaft 10 to the winding shaft 9.

The above-mentioned (a) and ((b) also apply to the apparatus of the third embodiment in which the electromagnetic induction heating member 2A is used as a fixing member, and the fixing film F uses a film having no electromagnetic induction heating itself. It is possible to have the same device configuration as in b) and (c).

<Fifth Embodiment> (FIG. 10) The image forming apparatus (FIG. 1) in the first embodiment is a four-color image forming apparatus.
A pulse multi-color image forming apparatus or the like may be used.
A configuration in which b is omitted may be employed. In addition, an arbitrary layer configuration such as a two-layer configuration of the heat generation layer 2a and the release layer 2c, a three-layer configuration of the heat insulation layer 2d, the heat generation layer 2a, and the release layer 2c, and a single layer of the heat generation layer 2a can be used. . The heat generating layer 2a may be formed by mixing a metal filler into a resin. FIG. 10 is a schematic configuration diagram of an example of a monochrome image forming apparatus. The image forming apparatus of this embodiment is a transfer type electrophotographic process utilizing, a process cartridge detachable type, and a laser beam printer.

The intensity of the laser beam L from the scanner 13 is modulated by the image information signal sent from the host computer, and an electrostatic latent image is created on the rotating photosensitive drum 11 as an image carrier. The intensity of the laser beam L and the irradiation spot diameter are appropriately set according to the resolution of the image forming apparatus and the desired image density. The portion of the electrostatic latent image on the photosensitive drum 11 where the laser beam L is irradiated is a bright area. To the potential _VL ,
Moiety otherwise formed by being held in the dark potential V _D which has been charged by the primary charger 12.

The photosensitive drum 11 rotates in the direction of the arrow, and the electrostatic latent images are sequentially developed by the developing device 14. The toner in the developing device 14 has a toner height by a developing sleeve 14a and a developing blade 14b which are a toner supply rotating body.
The tribo is controlled to form a uniform toner layer on the developing sleeve 14a. The developing blade 14b is usually made of metal or resin, and the resin blade is in contact with the developing sleeve 14a with an appropriate contact pressure. The toner layer formed on the developing sleeve 14a is moved by the rotation of the developing sleeve 14a itself.
And the voltage V applied to the developing sleeve 14a.
Due to the electric field formed by _DC and the surface potential of the photosensitive drum 11, V
Only the part of _L is visualized selectively.

The toner image on the photosensitive drum 11 is sequentially transferred by the transfer device 15 to the paper P sent from the paper feeding device. As a transfer device, in addition to the corona charger shown in the figure, there is a transfer roller system which supplies current from a power supply to a conductive elastic rotating body to transfer the paper while applying transfer charge to paper.

The paper on which the toner image has been transferred is sent to the fixing device 100 with the rotation of the photosensitive drum 11, and becomes a permanently fixed image by heating and pressing.

Reference numeral 16 denotes a cleaner, which removes residual substances such as untransferred toner from the surface of the rotating photosensitive drum 11 after the transfer.

Reference numeral 17 denotes a paper feed cassette in which transfer paper P as a recording material is loaded and stored. The loaded transfer paper P is separated and fed one by one by rotation of a paper feed roller 18, and a sheet path 19, The sheet is fed to the transfer unit at a predetermined control timing via the sheet path 21 of the registration roller pair 20.

The paper P on which the toner image has been fixed and has exited the fixing device 100 is discharged onto a paper discharge tray 25 via a sheet path 23 and a paper discharge roller pair 24.

The PC is a process cartridge which can be attached to and detached from the printer main body. In this embodiment, the photosensitive drum 11, charging device 14, developing device 14, and cleaner 16 are used.
Includes three process equipment. The combination of the process devices included in the process cartridge PC is not limited to the above, and is optional.

<Others> 1) In the above embodiment, the pressure roller 6 as the second member is used.
Is fixedly disposed, and the heating assembly 1 as the first member is pressed by the urging means to form a nip portion N between the two members. The nip portion N may be formed by pressing the pressure roller 6 by the urging means, or the nip portion N may be formed by pressing both the heating assembly 1 side and the pressure roller 6 side by the urging members. May be.

2) The image forming principle and method of the image forming apparatus is not limited to the electrophotographic process, but may be any other method such as a transfer type or a direct type electrostatic recording process and a magnetic recording process.

3) The pressure member 6 is not limited to the roller body, but may be another type of member such as a rotating belt type.

In order to supply thermal energy to the recording material from the pressing member 6 side, a heating means such as electromagnetic induction heating or a halogen lamp is also provided on the pressing member 6 side so that the recording material is heated to a predetermined temperature. The device configuration can also be adjusted.

4) The heating device of the present invention is not limited to the image heating and fixing device of the embodiment, but may be an image heating device for heating a recording material carrying an image to improve the surface properties such as gloss. Image heating equipment, other heating and drying equipment for heated materials,
It can be widely used as a means / apparatus for heat-treating a material to be heated, such as a heating lamination apparatus.

5) Electromagnetic induction heating type heating device using an exciting coil as a magnetic field generating means is shown in FIG.
As shown in the above example, the center of gravity of the exciting coil is brought closer to the nip from the center of rotation of the rotating electromagnetic induction heating member or rotating heat resistant member, so that the energy of the alternating magnetic flux generated by the excitation coil can be efficiently transferred to the electromagnetic induction heating The heat can be consumed by the member, and the temperature of the electromagnetic induction heating member can be quickly raised and energy consumption can be saved.

[0136]

As described above, according to the present invention, it is possible to reduce the heat generated by the exciting coil itself as the magnetic field generating means in the heating device of the electromagnetic induction heating type.
It is possible to provide an inexpensive exciting coil or a heating device of an electromagnetic induction heating system using the exciting coil by using a low-grade bundled wire. With low power consumption and shortened wait time (quick start), high image quality is maintained even for images with a large amount of toner such as full-color images in the image heating device of the image forming apparatus. As a result, it is possible to provide an apparatus capable of coping with high-speed operation at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an example of an image forming apparatus according to a first embodiment;

FIG. 2 is a schematic cross-sectional view of a fixing device as an electromagnetic induction heating type heating device.

FIGS. 3 (a) and 3 (b) are schematic diagrams of a layer structure of a fixing film having electromagnetic induction and heat.

FIG. 4 is an explanatory diagram of electric wires (bundled wires) constituting a coil (wire loop) of an exciting coil;

FIG. 5 shows a wire diameter φ of a thin copper wire constituting a bundle of an exciting coil.
Diagram of relationship between ₁ and self-heating value Q

FIG. 6 is a graph showing a result of examining a boundary line diameter φ ₀ of a thin wire in which self-heating of an exciting coil starts to increase using a frequency f as a parameter.

FIG. 7 is a schematic cross-sectional view of a fixing device as a heating device of the electromagnetic induction heating type in the second embodiment.

FIG. 8 is a schematic cross-sectional view of a fixing device as a heating device of an electromagnetic induction heating type in a third embodiment.

FIGS. 9A, 9B, and 9C are schematic diagrams of another example of a device configuration as a fourth embodiment; FIGS.

FIG. 10 is a schematic configuration diagram of an example of an image forming apparatus according to a fifth embodiment;

FIG. 11 is a diagram showing the relationship between the position of the center of gravity of the exciting coil and the nip portion.

[Explanation of symbols]

Reference Signs List 100 heating device (fixing device) of electromagnetic induction heating system 1 first member (heating assembly) 6 second member (pressing roller) 2 electromagnetic induction heating member (electromagnetic induction heating fixing film) 3 excitation coil 3a core wire ( 3b Insulating coating 3c Thin wire 3d Bundle wire 3e Ferrite core (excitation iron core) 4 Film guide member 5 Excitation circuit M Press roller driving means N Nip P Heated material (recorded material) t Toner image

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroki Kisu 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (21)

[Claims] 1. An insulated depth δ (f is the frequency of the exciting current) defined by δ = (πfμσ) ^-1/2 , wherein a bundle of a plurality of conductive wires insulated from each other is wound. , Μ is the magnetic permeability of the conductive wire, σ is the conductivity of the conductive wire)
Excitation coil, wherein a wire diameter phi ₁ of the conductive wire was φ ₁ ≦ δ. 2. An electromagnetic induction heating member, and a magnetic field generating means for applying a magnetic field to the electromagnetic induction heating member to generate heat,
A heating device for applying heat energy to a material to be heated by heat generated by an electromagnetic induction heating member, wherein the magnetic field generating means includes an exciting coil for generating an alternating magnetic field, and the exciting coil includes a plurality of conductive wires insulated from each other. The penetration depth δ is defined by δ = (πfμσ) ^-1/2 (f is the frequency of the exciting current, μ is the permeability of the conductive wire, and σ is the permeability of the conductive wire. Conductivity)
Heating apparatus, wherein a wire diameter phi ₁ of the conductive wire was φ ₁ ≦ δ. 3. An electromagnetic induction heat generating member, a first member having a magnetic field generating means for generating a magnetic field by applying a magnetic field to the electromagnetic induction heat generating member, and mutually press-contacting the first member directly or with another member interposed therebetween. A heating member that has a second member that forms a nip portion by applying heat energy to the material to be heated sandwiched and conveyed by the nip portion by the heat generated by an electromagnetic induction heating member. An exciting coil to be generated, the exciting coil being formed by winding a bundle of a plurality of conductive wires insulated from each other, and having a penetration depth δ defined by δ = (πfμσ) ^-1/2. (F is the frequency of the exciting current, μ is the magnetic permeability of the conductive wire, and σ is the conductivity of the conductive wire)
Heating apparatus, wherein a wire diameter phi ₁ of the conductive wire was φ ₁ ≦ δ. 4. The heating device according to claim 2, wherein the electromagnetic induction heating member is a rotating member or a traveling member. 5. The heating device according to claim 2, wherein the electromagnetic induction heating member is a fixed member. 6. The heating device according to claim 3, wherein the electromagnetically induced heat generating member is a rotated endless film member or a running end film member, and the second member side from the inside which is the first member side. A heating device, characterized in that the heating device is a laminate composed of at least an electromagnetic induction heating layer, an elastic layer, and a release layer in that order. 7. The heating device according to claim 3, wherein the electromagnetic induction heating member is a rotating endless film member or a running end film member, and the second member side from the inside which is the first member side. A heating device comprising: a laminated body including at least a heat insulating layer, an electromagnetic induction heating layer, an elastic layer, and a release layer in that order. 8. The heating device according to claim 3, wherein the electromagnetic induction heating member is a rotating endless film member or a running end film member, and the second member side from the inside which is the first member side. A heating device comprising: a laminate comprising at least an electromagnetic induction heating layer and a release layer in that order on the outside. 9. The heating device according to claim 3, wherein the electromagnetically induced heat generating member is a rotated endless film member or a running end film member, and the second member side from the inside which is the first member side. A heating device comprising: a laminate comprising at least an insulating layer, an electromagnetic induction heating layer, and a release layer in that order on the outside. 10. The heating device according to claim 3, wherein the second member is a rotary pressing member. 11. The heating device according to claim 3, wherein
A heating device, wherein the second member is a rotary pressurizing member, the electromagnetic induction heating member is a rotating member or a traveling member, and the electromagnetic induction heating member is rotated or traveled by rotation of the second member. . 12. The heating device according to claim 3, wherein
A heating device, wherein the electromagnetic induction heat generating member is a fixed member, and the fixed electromagnetic induction heat generation member and the second member are pressed against each other via a heat resistant film to form a nip portion. 13. The heating device according to claim 12, wherein the material to be heated is sandwiched and conveyed between the heat-resistant film in the nip portion and the second member. 14. The heating device according to claim 12, wherein the second member is a rotary pressing member. 15. The heating device according to claim 12, wherein the second member is a rotation pressing member, the heat-resistant film is a rotation member or a traveling member, and the heat-resistant film is driven by rotation of the second member. Is rotated or run. 16. The heating device according to claim 12, wherein the heat-resistant film has at least a heat-resistant resin layer and a separating member in order from the inside on the first member side to the outside on the second member side. A heating device, which is a laminate composed of a mold layer. 17. The heating device according to claim 3, wherein the center of gravity of the exciting coil is closer to the nip portion than the center of rotation of the rotating electromagnetic induction heating member or the rotating heat resistant member. Heating equipment. 18. The heating device according to claim 2, wherein the material to be heated is an image carrier on which an image is formed and carried, and the device is an image heating device that heats the image. A heating device, comprising: 19. The heating device according to claim 18, wherein the image heating process is an image fixing process on an image carrier. 20. An image forming apparatus for forming an image on an image carrier, and an image heating device for heating the image formed on the image carrier, wherein the image heating device is any one of claims 2 to 17. An image forming apparatus, comprising: 21. The image forming apparatus according to claim 20, wherein the heating process of the image is a fixing process of the image on the image carrier.