JPH04372974A - Heating device - Google Patents

Abstract

PURPOSE:To secure the good and stable fixing property of an image heating/ fixing device by removing the nonuniformity of the pressing force in the longitudinal direction of a heating nip section caused by the thermal expansion difference between a heating element and a film guide member when they are separate parts, conveying a heat--resistant film in a heating nip section with no wrinkle, and reducing the damages such as the folding and flaws of the film caused by corner sections of the heating element at the step section between the heating element and the film guide member when the heating nip section is conveyed and guided. CONSTITUTION:A heated member is fed through a heating nip section N together with a heat-resistant film 2 in close contact with the outer face of the heat-resistant film 2, the heat of a heating element is given to the heated member via the heat-resistant film 2 in a heating device, and the heating element is a heating resistor section 11 formed linearly or planarly on the film inner face guide face of a film guide member l guiding the inner face of the heat- resistant film 2.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention involves sandwiching the inner and outer sides of a heat-resistant film and arranging a heating body and a pressure member to face each other to form a heating nip, and then applying the heat to the member to be heated. Heating is performed by introducing the heated member between the outer surface of the heat-resistant film in the nip and the pressure member, bringing the member to be heated into close contact with the outer surface of the heat-resistant film, and passing the heat-resistant film through the heating nip together with the heat-resistant film. The present invention relates to a film heating type heating device that applies body heat to a heated member through a heat-resistant film.

This film heating type heating device is used for image heating and fixing, which is incorporated into image forming devices such as electrophotographic copying machines, laser beam printers, facsimile machines, microfilm reader printers, image display devices, and recording machines. A recording material (transfer material sheet, electrofax sheet, electrostatic recording sheet, printing An unfixed toner image corresponding to the desired image information, formed by an indirect (transfer) method or a direct method on the surface of a paper (such as paper), is heated and fixed as a permanently fixed image on the surface of the recording material carrying the image. It can be used as an image heating fixing device. Further, it can be used, for example, in a device that heats a recording material carrying an image to modify its surface properties (polishing, etc.), and a device that performs a temporary adhesion treatment.

0003

2. Description of the Related Art Conventionally, for example, a recording material heating device for thermally fixing an image uses a heating roller maintained at a predetermined temperature and a pressure roller having an elastic layer that presses against the heating roller. A heated roller system that heats the material while holding and conveying it is often used.

[0004] In addition, various other methods are known, such as a flash heating method, an oven heating method, a hot plate heating method, a belt heating method, and a high frequency heating method.

[0005] On the other hand, the present applicant, for example,
Publication No. 3182, Patent Application No. 153602-15
No. 3610, etc., includes a fixedly supported heating body (heater), a heat-resistant film that is moved while being in pressure contact with the heating body, and a pressure member that brings the recording material into close contact with the heating body through the film. We have proposed a heating device using a film heating method that heats and fixes an unfixed image formed and carried on the surface of the recording material by applying heat from a heating body to the recording material through the film. There is. This kind of film heating type equipment uses a heating element that heats up quickly and a thin film, so waiting time can be shortened (quick start).
The present invention is effective because it has the advantage of being able to prevent offset, and solving various drawbacks of conventional devices.

FIG. 7 shows a schematic configuration of an example of this type of image heat fixing device using an endless film as the heat-resistant film.

Reference numeral 51 denotes an endless belt-shaped heat-resistant film (hereinafter referred to as fixing film or film), which includes a driving roller 52 on the left side, a driven roller 53 on the right side,
A low heat capacity linear heating body 54 is disposed below between the driving roller 52 and the driven roller 53, and is suspended between the three members 52, 53, and 54 parallel to each other.

The fixing film 51 rotates clockwise at a predetermined circumferential speed as the driving roller 52 rotates clockwise, that is, the unfixed toner image Ta conveyed from the image forming section (A) side (not shown) is placed on the upper surface. It is rotationally driven at approximately the same peripheral speed as the conveyance speed (process speed) of the recording material sheet P as the heated member carried thereon.

Reference numeral 55 denotes a pressure roller as a pressure member, which pinches the downward film portion of the endless belt-shaped fixing film 51 and presses it against the lower surface of the heating body 54 by means of biasing means (not shown). They are brought into pressure contact and rotate in the forward and counterclockwise direction in the conveyance direction of the recording material sheet P.

The heating body 54 is a low heat capacity linear heating body whose length is in the direction (width direction of the film) that intersects the plane movement direction of the film 51.
base material) 54a, heating resistor (current-carrying heating resistor) 54
b. The surface protective layer 54c, the temperature measuring element 54d, etc. are fitted into and held in a groove provided on the lower surface of a heating element holding member 56 made of a heat insulating material, and the member 56 is fixedly supported by being attached to a support 57. There is.

A recording material sheet P carrying an unfixed toner image Ta on its upper surface, conveyed from an unillustrated image forming section (A), is guided by a guide 58 to a pressure contact portion between a heating member 54 and a pressure roller 55. The unfixed toner image surface enters between the fixing film 51 and the pressure roller 55 of the heating nip portion N (hereinafter referred to as the fixing nip portion), and the unfixed toner image surface is attached to the recording material sheet P.
The fixing film 51 passes through the fixing nip N in close contact with the lower surface of the fixing film 51, which is being rotated in the same direction at the same speed as the conveying speed of the fixing film 51, and overlaps with the film 51.

The heating element 54 is heated by energizing the heating resistor 54b at a predetermined timing, and the thermal energy on the side of the heating element 54 is applied to the side of the recording material sheet P in close contact with the film via the fixing film 51. In the process of passing through the fixing nip N, the toner image Ta is heated and becomes a softened and melted image.

The rotating direction of the fixing film 51 is reversed at a sharp angle at the edge S of the film guide member 55 where the curvature is large. Therefore, the recording material sheet P conveyed through the fixing nip N while overlapping the fixing film 51 is separated from the fixing film 51 by the curvature at the edge S and is discharged. By the time the toner reaches the paper discharge section, the toner has been sufficiently cooled and solidified and is completely fixed Tb on the recording material sheet P.

[0014]

[Problems to be Solved by the Invention] In the above conventional example, the heating body holding member 56 also serves as a film guide member that guides the inner surface of the fixing film 51, and the heating body 54 and the heating body holding member 56 are not integrated, and the film guide member When the heating element 54 was assembled to the heating element 56, there was a difference in level between the film running surfaces of both the heating element 54 and the heating element 56, which caused the following problems.

a. Heating body 54 and film guide member 56
Since they are separate parts, both 54 and 56 undergo different thermal expansions at a fixing temperature of around 160°C, and the pressure force in the longitudinal direction of the fixing nip N created by the heating body 54 and the pressure roller 55 is not applied. Make it uniform. This has led to poor running of the fixing film 51 and poor fixing.

b. Heating body 54 and film guide member 56
Due to the difference in level between the film running surfaces of both, the corners of the heating element 54 and the fixing film 51 slide before or after the fixing nip N, causing folds, scratches, tears, etc. on the inner surface of the fixing film 51. This may cause poor film running and may also lead to poor fixing.

The object of the present invention is to solve the above-mentioned problems a and b regarding film heating type heating devices.

[0018]

[Means for Solving the Problems] The present invention is an image forming apparatus characterized by the following configuration. (1) A fixing nip is formed by arranging a heating body and a pressure member facing each other with the inner and outer sides of the heat-resistant film sandwiched between them, and the heated member is placed on the outer surface of the heat-resistant film in the fixing nip. The heated member is introduced between the side and the pressure member, and the heated member is brought into close contact with the outer surface of the heat-resistant film, and the heated member is passed through the fixing nip together with the heat-resistant film, so that the heat of the heating body is transferred to the heat-resistant film. The heating device is a heating device that applies heat to a member to be heated through the heat-resistant film, and the heating body is a heating resistor portion formed in a linear or planar shape on the inner surface of the film of a film guide member that guides the inner surface of the heat-resistant film. A heating device characterized by: (2)
The heating device according to (1), wherein the film guide member is made of resin.

[0019]

[Operation] The inner surface of the heat-resistant film is guided by the film guide member and the heat-resistant film is conveyed and introduced into the heating nip. In this case, by configuring the heating body in a form in which a heating resistor portion is formed in a linear or planar shape on the inner surface of the film of the film guide member that guides the inner surface of the heat-resistant film,
Unlike conventional devices, the heating body and the film guide member are separate parts, which eliminates the non-uniformity of the pressing force in the longitudinal direction of the nip due to the difference in thermal expansion between the two. This makes it possible to transport the heat-resistant film without wrinkles. In addition, since the heating resistor portion is present on the surface of the film guide member with virtually no step, the heating nip portion of the film is transported due to the corner portion of the heating member at the step portion between the heating member and the film guide member, unlike conventional devices. Not only can damage such as bending and scratches at the time of introduction be reduced, but also the positional accuracy of the heating resistor section relative to the pressure member can be improved. Therefore, good and stable fixing performance is ensured in the image heat fixing device.

Furthermore, by forming the film guide member from a heat-resistant resin, it is possible to easily mold a guide shape that gently changes the film traveling direction before and after the heating nip, and it is possible to easily mold the guide shape so that the direction of travel of the film is gently changed before and after the heating nip. A shape that can increase the moment of inertia of area can be obtained, and when the film guide member is configured to also serve as pressure support, the pressure force at the heating nip portion can be made uniform in the longitudinal direction.

[0021]

[Example] <Example 1> (FIGS. 1 to 3) (1) Image forming apparatus example FIG. 3 shows a heating device according to the present invention as an image heating fixing apparatus 100.
1 is a schematic configuration diagram of an example of an image forming apparatus incorporating an image forming apparatus. The image forming apparatus of this example is a laser beam printer using a transfer type electrophotographic process.

60 is a process cartridge, which includes a rotating drum type electrophotographic photoreceptor (hereinafter referred to as drum) 61
・Charging device 62・Developing device 63・Cleaning device 64-4
The opening/closing section 65 of the device includes two process devices.
By opening the inside of the device, it can be attached to and removed from a predetermined position within the device.

The drum 61 is rotated in the clockwise direction as indicated by the image forming start signal, and the surface of the rotating drum 61 is uniformly charged to a predetermined polarity and potential by the charger 62.
A laser scanner 66 is applied to the charged surface of the drum.
The laser beam 67 modulated in accordance with the time-series electrical digital pixel signal of the desired image information outputted from the drum 61 is subjected to main scanning exposure writing, thereby creating an electrostatic charge corresponding to the desired image information on the surface of the drum 61. Latent images are formed one after another. The latent image is then developed into a toner image by a developing device 63.

On the other hand, the recording material sheet (transfer paper) P in the paper feed cassette 68 is separated and fed one by one by the cooperation of the paper feed roller 69 and the separation pad 70, and the drum 61 is rotated by the registration roller pair 71. The toner images on the side of the drum 61 are sequentially transferred to the surface of the fed recording material sheet P, and the toner images on the side of the drum 61 are sequentially fed to the pressure nip 73 which is a fixing section between the drum 61 and the transfer roller 72 that is in pressure contact with the drum 61. It is being transcribed. Transfer of the toner image from the drum 61 to the recording material sheet P is performed by charging the back side of the recording material sheet P by a transfer roller 72 with a polarity opposite to that of the toner image.

The recording material sheet P that has passed through the transfer section 73 is neutralized by a static eliminating needle 74 to which a voltage of opposite polarity to that of the transfer roller 72 is applied, separated from the surface of the drum 61, and introduced into a fixing device 100, which will be described later. The unfixed toner image is heat-fixed by the operation and action of step 100, and is outputted from the outlet 75 as an image-formed product (print).

The surface of the drum 61 from which the recording material sheet P has been separated through the transfer section 73 is subjected to removal of adhered contaminants such as untransferred toner by a cleaning device 64, and is used repeatedly for image formation. (2) Fixing device 100 FIG. 1 is a partially exploded perspective view of the fixing device 100, and FIG. 2 is a cross-sectional view of the main parts.

Reference numeral 1 denotes a gutter-shaped member having a substantially semicircular cross section and serving as a film guide member.

2 is a heat-resistant film as a fixing film, which in this embodiment is an endless cylindrical member;
It has an inner circumferential length larger than the circumferential length of the film guide member 1, and is fitted onto the outside of the film guide member 1, and the film guide member 1 guides the inner surface of the fixing film 2 over the entire length in the longitudinal direction.

3 is a pressure roller as a pressure member. It is rotatably supported by bearings between the left and right side plates of a fixing device chassis (not shown). 31 is a drive gear fixed to one shaft end of the roller.

The film guide member 1 has a thin film heating resistor 11 formed in the shape of a line or strip in the direction of the generatrix of the arc surface approximately at the center of the semicircular outer surface. Reference numerals 12 and 12 indicate flange members on both the left and right ends of the film guide member 1. One flange member is integrally molded with the film guide member 1, and the other flange member is a retrofitted member. With the flange member removed, the fixing film 2 is fitted over the film guide member 1, and then the other flange member is attached to the film guide member 1. The flange members 12 serve to control the meandering of the fixing film 2 that occurs when the fixing device is driven by regulating the ends of the fixing film.

The film guide member 1 has the fixing film 2 fitted thereon and the retrofitted flange member 12 fitted thereto to form one assembly, and the assembly is freely rotatable between the left and right side plates of the fixing device chassis as described above. The film guide member 1 is placed on the pressure roller 3 which is supported by a bearing, with the semicircular arc-shaped outer surface facing downward, substantially parallel to the pressure roller 3;
Pressure spring support members 13, 13 protrude outward from both left and right ends of the film guide member 1, and opposing spring receivers 15 (
Figure 3) By compressing the pressure springs 14 and 14 between them,
The fixing film 2 is sandwiched between approximately the center of the downward semicircular outer surface of the film guide member 1 and the pressure roller 3, and the pressure roller 3 is pressed against each other with a predetermined contact pressure (for example, a total pressure of 3 to 6 kg for A4 width). There is.

As shown in FIG. 2, the approximately central portion of the downward semicircular outer surface of the film guide member 1 that holds the fixing film 2 in contact with the pressure roller 3 is the fixing nip (heating nip) N. A thin film heating resistor 11 formed in the shape of a line or strip is positioned at the fixing nip N in the approximate center of the semicircular outer surface of the film guide member 1 in the direction of the generatrix of the arc surface.

In the apparatus of this embodiment, no tension is applied to the fixing film 2 in its circumferential direction except at the fixing nip N, and the fixing film 2 is only affected by the frictional force with the rotationally driven pressure roller 3. Rotate and run.

The material of the film guide member 1 may be metal, heat-resistant resin, etc., but if metal (for example, galvanized steel plate) is used, an insulating layer must be provided between it and the heating resistor 11. There are many problems, such as the fact that the shape of the end flange and the shape of the film guide are difficult to freely shape. In this example, a resin with heat resistance, insulation properties, and toughness (high rigidity, impact fracture resistance, and high mechanical strength) is used, for example, a polyimide resin or a composite material of polyimide resin and glass fiber, ceramic, fluororesin, etc. , or made of thermosetting resin such as phenol.

The linear or strip-shaped thin film heat generating resistor portion 11 formed on the film guide surface of the film guide member 1 is as follows:
For example, TaSiO2, silver palladium, Ta formed by vapor deposition, sputtering, CVD, screen printing, etc.
2N, RuO2, nichrome, etc. Electricity is applied to both longitudinal ends of the heat generating resistor section 11 at a predetermined timing, and the heat generating resistor section 11 generates heat.

The fixing film 2 has heat resistance, toner releasability,
It can be a single layer film with toughness or a composite layer film that has been subjected to desired surface treatment or lamination treatment. Examples include a heat-resistant single-layer film of about 50 μm polyester (PET) or polyimide (PI), or a composite layer film in which the film surface is further treated with tetrafluoroethylene (PTFE) to provide a release layer.

The recording material sheet P transferred to the fixing device 100 after receiving the unfixed toner image Ta is transferred to the pressure roller 3 which is rotated by a drive gear 31 which is rotationally driven by a gear on the drive source side (not shown). The fixing film 2 and the pressure roller 3 are conveyed and introduced into the fixing nip part N by the surface frictional force, and at least in the fixing nip part N, the fixing film 2 and the pressure roller 3 are prevented from slipping due to the contact pressure of the pressure springs 14. Sent at speed.

The process of passing through the fixing nip is a heating and pressurizing process, and the heat of the heat generating resistor 11 is transmitted to the recording material sheet P via the fixing film 2, and the unfixed toner Ta on the sheet P is melted and Pressurized. After passing through the fixing nip N, the fixing film 2 and the recording material sheet P are conveyed while remaining in close contact with each other due to the adhesive force of the melted and softened toner.

This conveyance process is a cooling process, and the heat of the softened and melted toner is radiated, the toner is cooled and solidified, and a permanently fixed image is formed on the recording material sheet P. After the cooling process, the fixing film 2 and the recording material sheet P are easily separated by toner cooling and solidification, and after separation, the recording material sheet P is transferred to the fixing device 1.
Ejected from 00.

The device of this embodiment has the following effects.

■. The fixing film is placed along the film guide surface of the film guide member 1 at least before the fixing film 2 is conveyed into the fixing nip portion N or where it passes through the fixing nip portion N, and the heating resistor portion 11 is formed on the film guide member 1 with a thin film. This will reduce wrinkles and wrinkles on the fixing film 2.
It is possible to prevent the occurrence of causes such as scratches and creases that may hinder the running of the fixing film 2, and a good and stable fixed image can be obtained.

[0042]■. By forming the heat generating resistor section 11 directly on the film guide member 1, it is no longer necessary to provide a separate base material for forming the conventional heat generating resistor section. Therefore, parts costs are reduced, and the problem of the difference in thermal expansion between the base material and the film guide member at a fixing temperature of around 160° C. is eliminated, and the pressure contact angle and position of the heating resistor 11 with respect to the pressure roller 3 and the fixing film 2 are eliminated. Improves accuracy.

[0043]■. Since the film guide member 1 is made of resin that can be easily processed into any shape, it is possible to freely create the shape that guides the fixing film 2 and the shape of the flange member 12 that regulates the ends of the fixing film.

[0044]Also, it is possible to create a shape that increases the moment of inertia of area in order to increase the rigidity in the longitudinal direction of the pressure spring support members 13, 13 while maintaining the guide shape. Therefore, the deflection of the pressure spring support members 13, 13 in the longitudinal direction becomes smaller, which causes meandering of the fixing film 2 in the longitudinal direction caused by uneven contact pressure, and poor film running and fixing such as uneven gloss of the fixed image. It can be prevented.

[0045]■. In addition, since the film guide member 1 is made of heat-resistant resin, the amount of heat generated in the heating resistor 11 is
The rate of transmission to the fixing film 2 and toner, which are the heated members in the fixing nip N, is due to the low thermal conductivity of the heat-resistant resin (for example, about 0.2 J/J for polyimide resin).
msecK), which is larger than the rate of diffusion from the heating resistor 11 into the air via the film guide member 1, and allows fixing with low energy.

<Embodiment 2> (FIG. 4) In this embodiment, the drive roller 4 and film guide member 1 are passed through the endless cylindrical fixing film 2, so that the direction of rotation of the fixing film 2 (arrow a) It provides tension. The fixing film 2 rotates and runs due to the surface friction force of the drive roller 4 rotated by the drive gear 41.

The pressure roller 3 is a driven roller that rotates due to the frictional force with the fixing film 2 while forming the fixing nip N by the contact pressure with the film guide member 1 caused by the pressure springs 14. .

The film guide member 1 in which the heating resistor 11 is formed on the surface inside the fixing nip (N) has a circumferential length of the guide surface at both longitudinal ends of the fixing film 2 such that one end is longer than the other end. The fixing film 2, which rotates and runs while contacting the pressure roller 3 and drive roller 4 arranged in parallel, moves in the direction of the long end of the guide circumference (arrow b) due to tension and speed difference in the circumferential direction. The structure has a meandering structure.

The meandering fixing film 2 moves in the b direction because the heat-resistant resin ribs 21 fixed to the fixing film 2 with uniform width and height on its outer peripheral surface are regulated by the deviation control plate 5. meandering is controlled.

The material and structure of the film guide member 1 and the fact that the heating resistor portion 11 is formed of a thin film on the guide surface are exactly the same as in the first embodiment. Therefore, this Example 2
Also, the same effects as in the first embodiment can be obtained. In addition, the second embodiment has the following unique effects.

That is, when the fixing film 2 is forced to meander in one direction and is controlled by the ribs 21, the ribs 21 ensure that the fixing film 2 always moves in one direction at the minimum speed. This is an important condition in terms of durability and controllability. In this embodiment, the pressure spring support member 13
・13. Since the film guide member 1 and heat generating resistor part 11 of the fixing film 2 to the fixing nip part N are integrated, the tension difference in the circumferential direction of the fixing film 2 that occurs at both ends in the longitudinal direction of the film can be accurately adjusted. It is possible to form.

Therefore, the desired meandering conditions, that is, the shifting speed and direction of the fixing film 2, are the same as when the above-mentioned meandering control is performed with a structure in which the conventional film guide member is not provided and the heating resistor is formed on the base material. Compared to this, it is possible to obtain a film fixing device with higher accuracy, which enables reliable film meandering control and which is also durable. <Embodiment 3> (FIGS. 5 and 6) FIG. 5 is a side view of the main parts of the device of this embodiment, and FIG. 6 is a front view.

In this embodiment, tension is applied in the circumferential direction of the fixing film 2 over the entire longitudinal direction. Inside the endless cylindrical fixing film 2 are a drive roller 4, a tension roller 6, a fixing film guide member 1 which also serves as a bearing support member for the drive roller 4, and a heat generating resistor formed on the film guide surface of the film guide member 1. Part 1
It is composed of 1.

When the fixing film 2, which has tension over the entire longitudinal direction, rotates due to the rotation of the drive gear 41, the surface frictional resistance of the drive roller 4 causes the fixing film 2 to exhibit tension as shown in FIG.
Rotate in the direction of arrow c inside. The meandering of the fixing film 2 during rotation is detected by a photosensor 7 (FIG. 6), and is controlled by controlling the movement of the tension roller 6 in the d direction or the e direction.

In this example, the shape of the guide surface of the film guide member 1 having the heat generating resistor portion 11 as in Example 2 allows the tension difference in the circumferential direction of the fixing film 2 to be reduced at both ends of the fixing film 2 in the longitudinal direction. The fixing film 2 is forcibly moved toward the end where the tension is high, and one end of the tension roller 6 is moved up and down using a solenoid or the like to enable meandering control.

The material and structure of the film guide member 1 and the fact that the heating resistor portion 11 is formed as a thin film on the guide surface are exactly the same as in the first embodiment. Therefore, the same effects as in the first embodiment can be obtained in the configuration of the third embodiment.

Furthermore, the effect of forcibly meandering the fixing film 2 using the film guide member 1 and simplifying the meandering control on one side is similar to that of the above-mentioned Example 2 in the configuration of the third embodiment. can get. In particular, in the third embodiment, by applying the film guide member 1 made of heat-resistant resin, which can be easily molded into a shape, to the bearing member of the drive roller 4, the positional accuracy (parallel This improves the meandering of the fixing film 2 due to positional accuracy, makes it easier to obtain the desired meandering speed and direction based on the shape of the fixing film guide, and allows for simpler film deviation control. .

[0058]

As described above, according to the present invention, in the film heating type heating device, the heating element and the film guide member are separate parts, so that the nip at the heating nip portion is caused by the difference in thermal expansion between the two. Nonuniformity in the pressing force in the longitudinal direction can be eliminated, and the heat-resistant film can be conveyed without wrinkles within the heating nip. In addition, since the heating resistor portion is present on the surface of the film guide member with virtually no difference in level, unlike conventional devices, the heating nip portion of the film is transported due to the corner portion of the heating element at the step portion between the heating member and the film guide member. In addition to reducing damage such as bending and scratches during installation,
The positional accuracy of the heating resistor portion with respect to the pressure member is improved. Therefore, in the image heat fixing device, good and stable fixing performance is ensured.

[Brief explanation of the drawing]

[Figure 1] Partially exploded perspective view of the main parts of the device of the first embodiment

[
Figure 2: Cross-sectional view of main parts

[Fig. 3] A schematic configuration diagram of an example of an image forming apparatus incorporating the apparatus.

[Figure 4] Partially exploded perspective view of the main parts of the second embodiment device

[
Figure 5: Side view of main parts of the device of the third embodiment

[Figure 6]
Its front view

[Figure 7] Schematic diagram of an example of a film heating type heating device

[Explanation of symbols]

1 Film guide member 2 Heat resistant film (fixing film) 3 Pressure member (pressure roller) 11 Heat generating resistor 12 Flange member 13 Pressure spring support member 14 Pressure spring N Heating nip part (fixing nip part)

Claims (2)

[Claims] 1. A heating nip is formed by arranging a heating body and a pressure member facing each other with the inner and outer sides of the heat-resistant film sandwiched between them, and the member to be heated is attached to the heat-resistant film in the heating nip. The member to be heated is introduced between the outer surface side of the heat-resistant film and the pressure member, and the member to be heated is brought into close contact with the outer surface of the heat-resistant film, and the heat-resistant film is passed through the heating nip portion with the heat-resistant film. The heating device is a heating device that applies heat to a member to be heated through a film, and the heating body is a heating resistor portion formed in a linear or planar shape on the inner surface of the film of a film guide member that guides the inner surface of the heat-resistant film. be,
A heating device characterized by: 2. The heating device according to claim 1, wherein the film guide member is made of resin.