JP2002373774A - Heating device, heating fixing device, and image forming dxevice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems that torsional deformation is easily caused by residual twisting stress generatecl when assembled wires are twisted, an appropriate coil shape is difficult to be held, heating distribution becomes uneven by the torsional deformation, the manufacture of an induction coil unit is difficult, disadventaging mass production. SOLUTION: This heating device is equipped with an induction coil for generating an alternating magnetic field, a heating member generating heat by electromagnetic induction, and a pressing member installed to be pressed against the heating member. The induction coil is formed to hold the specified shape by press molding a lits wire formed by twisting strands, or the induction coil is formed so as to hold the specified shape by self melt bonding of the litz wire, or the induction coil is formed so as to hold the specified shape by setting in one body the litz wire formed by twisting the strands.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating member having an induction coil for generating an alternating magnetic field, generating heat by electromagnetic induction, and a pressing member arranged in pressure contact with the heating member. A heating device for performing heat treatment of the sheet by nipping and conveying, a heat fixing device for applying heat and pressure to the sheet by applying the heating device to heat and fix an unfixed toner image on the sheet, and the heat fixing device The present invention relates to an image forming apparatus such as an electrophotographic copying machine, a printer, and a facsimile to which the invention is applied.

[0002]

2. Description of the Related Art An electrophotographic copying machine or the like is provided with a heating device for heating and fixing a toner image transferred onto a sheet such as a recording material as a recording medium, recording paper or a transfer material onto the sheet. I have. The heating device includes, for example, a fixing roller also referred to as a heating roller that thermally melts toner on a sheet, and a pressure roller that presses the fixing roller to nip and convey the sheet.

[0003] The fixing roller is formed in a hollow shape, and a heating element is held on a central axis of the fixing roller by holding means. The heating element is formed of, for example, a tubular heating heater such as a halogen lamp, and generates heat when a predetermined voltage is applied.

Since this halogen lamp is located at the center axis of the fixing roller, heat generated from the halogen lamp is uniformly radiated to the inner wall of the fixing roller, and the temperature distribution of the outer wall of the fixing roller is uniform in the circumferential direction. Become.

The outer wall of the fixing roller is heated until its temperature reaches a temperature suitable for fixing (for example, 150 to 200 ° C.). In this state, the fixing roller and the pressure roller rotate in opposite directions while being pressed against each other, and pinch and convey the sheet to which the non-toner has adhered. At a pressure contact portion (hereinafter also referred to as a nip portion) between the fixing roller and the pressure roller, untoned toner on the sheet is melted by heat of the fixing roller, and is fixed to the sheet by pressure acting on both rollers.

However, in the above-described heating device provided with a heating element composed of a halogen lamp or the like, since the fixing roller is heated by using the radiant heat from the halogen lamp, the temperature of the fixing roller is reduced after the power is turned on. It takes a relatively long time to reach a predetermined temperature suitable for heat fixing (hereinafter referred to as "warm-up time"). During that time, the user cannot use the copier,
There was a problem that a long wait was required.

On the other hand, if a large amount of power is applied to the fixing roller in order to shorten the warm-up time and improve the operability of the user, the power consumption in the heating device increases, which is against energy saving. Had occurred. For this reason, in order to increase the value of products such as copiers, attention and emphasis has been placed on achieving both energy saving (low power consumption) of the heating device and improvement of user operability (quick print) at the same time. Is coming.

[0008] Japanese Patent Application Laid-Open No.
As shown in JP-A-9-33787, an induction heating type heating device using high-frequency induction as a heating source has been proposed. In this heating device, a coil is concentrically arranged inside a hollow fixing roller made of a metal conductor, and a high-frequency magnetic field generated by flowing a high-frequency current through the coil generates an induced eddy current in the fixing roller, thereby fixing the image. The fixing roller itself generates Joule heat by the skin resistance of the roller itself. According to the heating device of the induction heating system, the electric-heat conversion efficiency is extremely improved, so that the warm-up time can be reduced.

Conventionally, in such an induction coil using a high-frequency current, since the current flows on the surface of the conducting wire due to the skin effect, the area which can be effectively used in the cross section of the induction coil is reduced, and the resistance value increases. I will. Therefore, a litz wire is used to increase the surface area of the induction coil. A litz wire is a stranded wire obtained by twisting and knitting a large number of individually insulated wires, and can reduce the skin effect.

[0010]

However, in such an induction coil using a litz wire, an assembly wire composed of several tens to several hundreds of enamel-coated wires is formed on the surface of a heating member such as a fixing roller. Although it must be wound along, the twisting deformation as shown in FIG. 3 is apt to occur due to the residual strain stress when the gathering wires are bundled, and there is a problem that it is difficult to properly maintain the coil shape.

When the induction coil undergoes torsional deformation, it becomes difficult to arrange the induction coil uniformly along the surface of a heating member such as a fixing roller, the gap between the coil and the roller is locally disturbed, and the heat generation distribution becomes uniform. Will not be. Further, if the shape is easily deformed by torsional deformation, it becomes difficult to manufacture the induction coil unit, which is not good for mass productivity.

In addition, in the case of a litz wire in which wires are bundled, the wire cross-sectional area (occupation ratio) per unit cross-sectional area tends to be low, and an induction coil is disposed inside a heating member such as a small-diameter fixing roller. However, a narrow internal space could not be used effectively with such a heating device. When the space factor is low, the area of the induction coil occupied by the current is small because the current can flow and the area can be used effectively. Therefore, the electric resistance value is high, and the induction coil easily generates Joule heat. For this reason, there arises a problem that the temperature rises to or above the heat-resistant temperature of the holding member of the induction coil and the insulating coating applied to the litz wire. Particularly, in a heating device of a type in which an induction coil is arranged inside a heating member, the ambient temperature of the induction coil is high, and the occupied area in which the induction coil can be used is limited, so this problem is serious.

The present invention eliminates such deformation of the induction coil, thereby facilitating the manufacture, preventing the temperature of the induction coil from rising by effectively utilizing the inside of the heating member, and applying the heating device to a heating device. It is an object of the present invention to provide a heat fixing device that reliably heat-fixes a formed unfixed toner image to a sheet and an image forming apparatus that performs high-quality image formation by applying the heat fixing device.

[0014]

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

(1) A heating member having an induction coil for generating an alternating magnetic field and generating heat by electromagnetic induction, and a pressing member arranged in pressure contact with the heating member are provided. A heating device for performing a heat treatment on the sheet, wherein the induction coil is formed in a wound shape and molded so that its self shape is maintained in a predetermined shape.

(2) The induction coil according to the above (1), wherein the litz wire formed by bundling the strands is formed by press molding so that the self-shape is maintained in a predetermined shape. apparatus.

(3) The induction coil according to the above (1) is a litz wire formed by binding element wires, and is formed so that its self-shape is maintained in a predetermined shape by self-fusion. Characteristic heating device.

(4) The induction coil according to the above (1) is a litz wire obtained by bundling strands of wires, and is solidified by an integrated material.
A heating device characterized by being formed so that its self-shape is maintained in a predetermined shape.

(5) The heating device according to (4), wherein the integrated product is any one of an adhesive, a resin, and a glass mold.

(6) The heating device according to any one of (1) to (4), wherein the induction coil is molded so as to face the heating member while being opposed to the heating member.

(7) In a heating device having a heating means provided with a heating means for nipping and conveying a sheet having an unfixed toner image formed on the surface thereof and applying the unfixed toner image on the sheet, (6) A heating fixing device to which the heating device according to any one of (6) is applied.

(8) Image forming means for forming an unfixed toner image corresponding to a document image or an input image signal on a sheet, and heat fixing means for heating and fixing the unfixed toner image on the sheet on the sheet An image forming apparatus comprising: the heat fixing unit according to (7) as the heat fixing unit. The present invention is achieved by such a fixing device and an image forming apparatus.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment) <First Embodiment> (1) Example of Image Forming Apparatus FIG. 1 is a schematic structural model diagram showing an example of an embodiment of an image forming apparatus according to the present invention. The image forming apparatus of this embodiment is a laser beam printer using a transfer type electrophotographic process.
In FIG. 1, reference numeral 101 denotes an electrophotographic photosensitive drum as an image carrier, which is rotated at a predetermined peripheral speed in a clockwise direction indicated by an arrow.

Reference numeral 102 denotes a charging roller having conductivity and elasticity as charging means, which is brought into contact with the photosensitive drum 101 with a predetermined pressing force.
Rotates or is driven to rotate by the rotation of.
When a predetermined charging bias voltage is applied to the charging roller 102 from a power supply unit (not shown), the peripheral surface of the rotating photosensitive drum 101 is uniformly contact-charged to a predetermined polarity and potential.

Reference numeral 103 denotes an exposure device as information writing means. The exposure device 103 is a laser scanner that outputs a laser beam modulated according to a time-series electric digital pixel signal of image information,
, A scanning exposure L is performed on the uniformly charged surface of the rotating photosensitive drum 101. As a result, an electrostatic latent image corresponding to the scanning exposure pattern is formed on the surface of the photosensitive drum 101.

Reference numeral 104 denotes a developing device,
The electrostatic latent image formed on the first surface is developed as a toner image. Reference numeral 104a denotes a developing roller to which a predetermined developing bias voltage is applied from a power supply unit (not shown).

Reference numeral 105 denotes a transfer roller having conductivity and elasticity as a transfer means, which is pressed against the photosensitive drum 101 with a predetermined pressing force to form a transfer nip portion T. A sheet P (hereinafter, also referred to as a recording sheet) such as a recording medium, a recording sheet, or a transfer sheet is fed to the transfer nip portion T from a sheet feeding unit (not shown) at a predetermined control timing, and is nipped and conveyed. Then, the toner image on the photosensitive drum 101 side is sequentially transferred to the recording paper P side. An appropriate bias voltage having a polarity opposite to the charging polarity of the toner is applied to the transfer roller 105 from a power supply (not shown) at a predetermined control timing.

Reference numeral 106 denotes a heating device (the heating device of the present invention applied as an image heating and fixing device) for heating and fixing an unfixed toner image transferred from the surface of the photosensitive drum 101 to the recording paper P on the recording paper. Recording paper P passed through section T
Are sequentially separated from the surface of the photosensitive drum 101 and introduced into the heating device 106, where the unfixed toner image on the recording paper P is heated and pressed to be heated and fixed on the recording paper P.
The recording paper P that has passed through the heating device 106 is discharged as an image-formed product (copy, print).

Reference numeral 107 denotes a photosensitive drum surface cleaning device that removes contaminants on the photosensitive drum surface such as transfer residual toner and paper powder remaining on the surface of the photosensitive drum 101 after the recording paper is separated, and cleans the surface. The photosensitive drum surface cleaned by the cleaning device 107 is repeatedly subjected to image formation.

(2) Heating Device (Heating Fixing Device) 106 FIG. 2 is a schematic cross-sectional view of the heating device 106 of the present invention. The heating device 106 records an unfixed toner image t on a fixing nip portion N which is a pressure contact portion between a fixing roller 1 as a heating member to be induction-heated and a pressing roller 2 as a pressing member. A heat roller type in which a recording paper P such as a material or an OHT is introduced and nipped and conveyed, and an unfixed toner image t is thermally and pressure-fixed to the surface of the recording paper P by the heat and the nip pressure of the fixing roller 1 in the fixing nip N. Device.

The fixing roller 1 has an outer diameter of 40 mm and a thickness of 0.1 mm.
7 mm is a core metal cylinder made of iron, which is a magnetic metal member. A layer of a fluororesin such as PTFE or PFA having a thickness of 10 to 50 μm may be provided on the outer peripheral surface in order to enhance the releasability of the surface. Both ends of the fixing roller 1 are rotatably supported by a fixing unit frame (not shown) and supported by being mounted on the fixing unit frame. The driving roller (not shown) is driven to rotate clockwise at a predetermined peripheral speed in a direction indicated by an arrow.

The pressure roller 2 comprises a hollow cored bar 2a and an elastic layer 2 which is a heat-resistant rubber layer formed on the outer peripheral surface thereof.
b. The pressure roller 2 is arranged in parallel with the fixing roller 1 below the fixing roller 1 so that both ends of the cored bar 2a are rotatably supported by a fixing unit frame (not shown) and supported by a spring. The fixing roller 1 is pushed up and urged in the rotation axis direction of the fixing roller 1 by an urging mechanism (not shown) using, for example, to press the lower surface of the fixing roller 1 with a predetermined pressing force.

When the pressure roller 2 is pressed against the fixing roller 1, the elastic layer 2 b is elastically deformed at the pressure contact portion with the fixing roller 1, and is fixed between the fixing roller 1 and the fixing roller 1 with a predetermined width as a heated material heating section. A nip N is formed. In this example, the pressure roller 2 is loaded with a total pressure of about 304 N (about 30 kg weight), and the nip width of the fixing nip portion N in this case is about 6 m.
m. However, depending on circumstances, the nip width may be changed by changing the load. The pressure roller 2 is driven to rotate by the pressure contact frictional force at the fixing nip portion N in accordance with the rotational driving of the fixing roller 1.

Reference numeral 9 denotes an induction coil assembly as a magnetic flux generating means, which comprises an induction coil 3, a magnetic core 4, a coil holder 5, and the like. This coil holder 5 is made of PP
This is a member having a semicircular trough-shaped cross section made of a heat-resistant resin such as S, PEEK, and phenol resin. The induction coil 3 wound in a boat shape inside the coil holder 5 and a flat ferrite having a thickness of 4 mm are formed into a T-shape. The combined magnetic core 4 is housed as an induction coil assembly 9.

The induction coil assembly 9 is held by the stay 6 and inserted into the hollow portion of the fixing roller 1 so that the semi-circular surface of the coil holder 5 faces downward. It is fixed and supported on the frame. Reference numeral 10 denotes a recording paper separating claw that is disposed on the recording paper exit side of the fixing nip portion N, in contact with or close to the surface of the fixing roller 1.

Next, the operation will be described.

The fixing roller 1 is driven to rotate, and the pressure roller 2 is driven to rotate.
An alternating current of １００100 kHz is applied. The magnetic field induced by the alternating current causes an eddy current to flow on the inner surface of the fixing roller 1, which is a conductive layer, to generate Joule heat. That is, the fixing roller 1 is induction heated.

The temperature of the fixing roller 1 is detected by a temperature sensor 7 such as a thermistor arranged so as to be in contact with the surface of the fixing roller, and the detected temperature information (detection signal) is input to the control circuit 12. The control circuit 12 adjusts the surface temperature of the fixing roller 1 to a predetermined constant temperature based on the input detected temperature information, that is, automatically controls the temperature of the fixing nip N to a predetermined fixing temperature. And the excitation circuit 11
The power supply to the induction coil 3 is increased or decreased.

In a state where the fixing roller 1 and the pressure roller 2 are rotated and the fixing roller 1 is heated by induction heating to a predetermined temperature, the recording paper carrying the unfixed toner image t P is guided by the conveyance guide 8 and introduced into the fixing nip portion N to be nipped and conveyed, and the unfixed toner image t is hot-pressed and fixed on the recording paper P by the heat of the fixing roller 1 and the nip pressure. The recording paper P that has left the fixing nip N is separated from the surface of the fixing roller 1 and is discharged and conveyed.

In order to increase the heat generation of the fixing roller 1, the number of turns of the induction coil 3 is increased, the magnetic core 4 is made of ferrite or permalloy having a high magnetic permeability and a low residual magnetic velocity density, or the AC current is reduced. It is better to increase the frequency.

As shown in FIG. 4, the induction coil 3 of the present invention is formed by forming a litz wire into a coil winding shape 3 'and then press-molding the same using press dies 15A and 15B. 5, the litz wire is condensed and compressed as shown in FIG. 5, there is no torsional deformation as seen in FIG. 3 of the conventional example, and the space factor can be increased by 30% to 50%. is there.

In the case where A4 plain paper is actually fixed at a rate of 30 sheets per minute for one continuous hour using a conventional winding, the temperature of the induction coil rises to 240 ° C. or more, and the temperature of the coil increases. While the temperature was raised to the heat-resistant temperature or higher, it was confirmed that the temperature of 220 ° C. or lower was maintained in the induction coil using the present invention. Further, since the fixing roller 1 is arranged so as to be uniform along the entire length thereof, the temperature distribution becomes uniform. Furthermore, since the coil shape is stable, the induction coil can be easily mounted on the holder 5 without collapse.

Further, according to the embodiment of the present invention, the enamel wire is used for the litz wire, but the invention is not limited to this.
A strand having a self-fusion layer may be used. In this case, the wound body processed into the coil winding shape is heated and pressurized to a temperature equal to or higher than the melting point of the self-fusing layer, and after the self-fusing layer is integrated, cooled and solidified, and then the pressure is released and the winding is performed. The body will be formed into its final shape. Thereby, a strong induction heating coil can be manufactured. In addition, as a material of the self-fusing layer, an epoxy-based or heat-resistant polyester-based material does not need to be softened by a solvent or the like, and heat resistance is improved, so that it is preferable.

Even more preferably, once the litz wire is formed in the coil winding shape 3 ′, the press dies 15 A and 15
It is more effective to press-mold with B and then solidify the induction coil with an integrated material such as an adhesive, a resin, or a glass mold. As the adhesive, an epoxy-based or silicon-based adhesive can be used, and as the resin, a heat-resistant PPS or a liquid crystal polymer is preferable.

<Embodiment 2> The power factor range of the present invention can be effectively applied to various types of induction heating type heating devices other than the induction heating type heating device of the first embodiment. It is. 6 to 9 show examples of various types of induction heating type heating devices.

The heating device shown in FIG. 6 uses an endless or cylindrical magnetic metal belt 1 A as an induction heating member instead of the fixing roller 1. The magnetic metal belt 1A is a laminated member including a magnetic metal layer or a magnetic metal member itself.

The magnetic metal belt 1A is sandwiched between the coil holder 5 of the inner induction coil assembly 9 and the outer pressing roller 2, and the coil holder 5 and the pressing roller 2 are pressed against each other. Thus, a fixing nip portion N is formed.

In this apparatus, the pressure roller 2 is rotationally driven in the counterclockwise direction indicated by the arrow by the driving means M (pressure roller drive system). The rotational force acts on the magnetic metal belt 1A by the frictional contact between the pressure roller 2 and the magnetic metal belt 1A at the fixing nip portion N due to the rotation of the pressure roller 2, and the magnetic metal belt 1A is rotated. Is rotated in the clockwise direction indicated by the arrow while sliding in the fixing nip portion N while closely contacting the lower surface of the coil holder 5 of the induction coil assembly 9.

The magnetic metal belt 1A is induction-heated by the magnetic flux generated by the induction coil 3, and the recording paper P as a material to be heated is introduced into the fixing nip N and heated.

The heating device shown in FIG. 7 is of a type that uses a rolled, wound, long web-shaped magnetic metal belt 1B as an induction heating member. The magnetic metal belt 1B is moved from the feeding shaft 13 to the winding shaft 14 via the fixing nip N.

The magnetic metal belt 1B is a laminated member including a magnetic metal layer or a magnetic metal member itself. The magnetic metal belt 1B is induction-heated in the fixing nip N by the magnetic flux generated by the induction coil 3, and the recording paper P as a material to be heated is introduced into the fixing nip N and heated.

The heating device shown in FIG.
A magnetic metal strip 1C as an induction heating member is fixedly arranged along the length of the holder at a substantially central portion of the lower surface of the lower surface of the induction coil 3, the magnetic core 4, the coil holder 5, and the magnetic metal strip 1C. A cylindrical heat-resistant film (fixing film) 15 is externally fitted, and the fixing film 15 is sandwiched between the fixed magnetic metal strip 1C and the pressure roller 2 to form a magnetic metal strip 1C. And the pressure roller 2 are pressed against each other to form a fixing nip portion N.

In this apparatus, the pressure roller 2 is rotationally driven in the counterclockwise direction of the arrow by the driving means M (pressure roller drive system). The rotational force acts on the fixing film 15 by the pressure contact frictional force at the fixing nip N between the roller 2 and the fixing film 15 due to the rotation of the pressure roller 2, and the inner surface of the fixing film 15 is , While rotating in close contact with the lower surface of the fixed magnetic metal strip 1C, and rotating in the clockwise direction indicated by the arrow.

The fixed magnetic metal strip 1C is induction-heated by the magnetic flux generated by the induction coil 3, and the fixing nip N
Then, the recording paper P as a material to be heated is introduced and heated by the heat of the fixed magnetic metal strip 1C via the fixing film 15 (film heating method).

The heating device shown in FIG. 9 is the same as the heating device of the film heating system shown in FIG. It is moved to the side 14 via the fixing nip N.

The fixed magnetic metal strip 1C is induction-heated by the magnetic flux generated by the induction coil 3 so that the fixing nip N
Then, the recording paper P as a material to be heated is introduced, and is heated by the heat of the fixed magnetic metal strip 1C via the fixing film 15.

Although the above-described embodiment is a transfer type electronic copying apparatus, the image forming process and means may be a direct type in which a toner image is formed and carried directly on an electrofax paper or an electrostatic recording paper, or a magnetic recording apparatus. Copiers of the type that forms an image with heat-fusible toner on recording paper by an image forming type or other appropriate image forming process and means, and heats and fixes it.
The present invention can be effectively applied as a heat fixing device in various image forming apparatuses such as a laser beam printer, a facsimile, a microfilm reader printer, a display device, and a recording machine.

The heating device of the present invention is not limited to the heating and fixing device of the embodiment, but may be any other device such as an image heating device which heats a recording paper carrying an image to improve the surface properties such as gloss and the like. An image heating device that heats the recording paper carrying the paper and presumably attaches an image, a heating device that feeds a sheet material such as a recording material and recording paper, and performs a drying process, a wrinkle removal process, a lamination process, and the like. It can be used.

[0060]

As described above, according to the first aspect of the present invention, a heating member having an induction coil for generating an alternating magnetic field and generating heat by electromagnetic induction is pressed against the heating member. In a heating device comprising a pressing member arranged in a predetermined position and performing heat treatment of the sheet by pinching and conveying the sheet, the induction coil is formed in a winding shape, and the self-shape is maintained in a predetermined shape. Since the induction coil is molded, deformation of the induction coil can be eliminated, manufacturing can be facilitated, and the temperature rise of the induction coil can be prevented by effectively utilizing the inside of the heating member.

According to the invention as set forth in claims 2 to 5 of the present application, the induction coil is formed by press-forming a litz wire based on strands so that its self-shape is maintained in a predetermined shape. The induction coil is a litz wire formed by bundling the strands, and is formed so that the self-shape is maintained in a predetermined shape by self-fusion.The induction coil is a litz wire formed by bundling the strands. Solidified with an adhesive, resin, glass mold, etc., and molded so that its self-shape is maintained in a predetermined shape, preventing torsional deformation of the induction coil, facilitating production and occupying space. It is possible to prevent a rise in temperature by increasing the rate.

According to the invention described in claim 6 of the present application,
Since the induction coil is formed so as to be opposed to the heating member, the heating member has no heat generation unevenness, and uniform heating can be performed over the entire length.

According to the invention described in claim 7 of the present application,
The heating device comprising a heating unit for nipping and conveying a sheet having an unfixed toner image formed on the surface thereof and heating and fixing the unfixed toner image on the sheet, wherein the heating unit is used as the heating unit. Since the heating device described in any one of 5 is applied, it is possible to obtain a heat fixing device that reliably heats and fixes an unfixed toner image formed on a sheet to the sheet.

According to the invention described in claim 8 of the present application,
Image forming apparatus comprising: an image forming unit that forms an unfixed toner image corresponding to an original image or an input image signal on a sheet; and a heat fixing unit that heats and fixes the unfixed toner image on the sheet onto the sheet. In the apparatus, since the heat fixing unit according to claim 6 is applied as the heat fixing unit, there is an effect that an image forming apparatus that performs high quality image formation can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration model diagram of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a heating device.

FIG. 3 is a torsion deformation diagram of a litz wire.

FIG. 4 is a sectional view of an induction coil.

FIG. 5 is a condensed state diagram of a litz wire.

FIG. 6 is a schematic cross-sectional view showing an induction heating type heating device.

FIG. 7 is a schematic cross-sectional view showing an induction heating type heating device.

FIG. 8 is a schematic cross-sectional view showing an induction heating type heating device.

FIG. 9 is a schematic cross-sectional view showing an induction heating type heating device.

[Explanation of symbols]

1: fixing roller (heating member), 2: pressing roller (pressing member), 3: induction coil, 4: magnetic core (core material), 5: coil holder (supporting member), 6: stay, 7: temperature Sensor (temperature detecting element), 8: conveyance guide, induction coil assembly, 10: separation claw, 11: excitation circuit, 12: control circuit, P: sheet (recording material, recording paper, transfer paper, etc.),
t: toner image

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H033 AA23 AA31 BA26 BB05 BB13 BB18 BB21 BB29 BB30 BE06 CA44 3K059 AA08 AB19 AB20 AB28 AD03 AD04 AD05 AD07

Claims (8)

[Claims] A heating member for generating heat by electromagnetic induction; and a pressing member disposed in pressure contact with the heating member. In a heating device for performing a heat treatment of the sheet,
The heating device according to claim 1, wherein the induction coil is formed in a wound shape, and is formed so that a self-shape is maintained in a predetermined shape. 2. The heating device according to claim 1, wherein the litz wire formed by bundling the strands is formed by press molding so that the self-shape is maintained in a predetermined shape. . 3. The induction coil according to claim 1, wherein the induction coil is a litz wire formed by bundling strands, and is formed so that a self-shape is maintained in a predetermined shape by self-fusion. And heating device. 4. The induction coil according to claim 1, wherein the induction coil is a litz wire formed by bundling strands of wire, solidified by an integrated material, and formed so that its self-shape is maintained in a predetermined shape. A heating device. 5. The integrated product according to claim 4, wherein the integrated product is an adhesive,
A heating device characterized by being one of a resin and a glass mold. 6. The heating device according to claim 1, wherein the induction coil is formed so as to face the heating member while being opposed to the heating member. 7. A heating and fixing device comprising: a heating means for nipping and conveying a sheet having an unfixed toner image formed on a surface thereof and heating and fixing the unfixed toner image on the sheet. A heating fixing device to which the heating device according to any one of claims 1 to 6 is applied. 8. An image forming means for forming an unfixed toner image corresponding to a document image or an input image signal on a sheet, and a heat fixing means for heating and fixing the unfixed toner image on the sheet on the sheet. An image forming apparatus comprising: the heat fixing unit according to claim 7 as the heat fixing unit.