JPH11195475A - Heating roller for fixing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating roller facilitating assembling process, and reducing working costs. SOLUTION: A heat resistant insulating sheet 13 is constituted by disposing a press portion region X constituted by affixing a stainless steel thin plate- formed rectangular elastic body 6 on insulating base material 14 made of polyimide resin-made film material, a heating portion region Y constituted by affixing a resistant heating body 17 made of stainless steel thin plate, and insulating portion region Z constituted by one part of the insulating base material 14. The elastic body 6 and the resistant heating body 17 are integrally formed by affixing the stainless steel thin plate on the insulating base material 14, and conducting etching treatment. The heat resistant insulating sheet 13 constituted this way is wound so that the press portion region X forms a layer most inside, the heating portion region, Y, the insulating portion region Z form layers outside the same in turn, and is mounted inside a roller main body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat fixing device provided in an image forming apparatus such as a printer or a copying machine for fixing a recording material adhered onto a recording medium by heating and melting or softening the recording material. Heating roller (hereinafter,
Simply referred to as “heating roller”).

[0002]

2. Description of the Related Art In a conventional image forming apparatus, for example, an electrophotographic printer or copier, a heating roller of a fixing device provided for fixing toner as a recording material onto paper as a recording medium is made of aluminum or aluminum. 2. Description of the Related Art In many cases, a halogen lamp is arranged inside a hollow cylindrical roller formed of stainless steel, and the entire roller is heated to a constant temperature by radiant heat generated by light emission of the halogen lamp.

However, such a heating roller has a low thermal efficiency because the halogen lamp is disposed at the center of the heating roller and is not in close contact with the roller surface. However, there is a problem that it takes a long time to reach a predetermined temperature suitable for fixing the image.

[0004] In order to solve the above problem, in recent years, a heating roller provided with a resistance heating element layer on the inner peripheral surface of the heating roller and using the resistance heating element layer as a heat source has been adopted. For example,
The heating roller 110 disclosed in JP-A-8-194401 shown in FIGS. 6 and 7 has an adhesion preventing layer 112 formed on the outer peripheral surface of a hollow cylindrical roller body 111 having good thermal conductivity. In addition, a resistance heating member 113 is bonded and fixed to the inner peripheral surface of the roller body 111. The resistance heating member 113 is a flexible heating element sheet in which a resistance heating element 117 is attached to the surface of an insulating film material 114 made of a polyimide resin film having heat resistance and insulation properties. The resistance heating element 117 is configured by attaching a resistance member 117a made of one or more stainless steel or copper foil films in a predetermined pattern, and providing power supply electrodes 117b at both ends. The resistance member 117a has a region having a different cross-sectional area in the axial direction of the roller body 111.
1 is adjusted so that the temperature of the outer peripheral surface becomes uniform.

As described above, the resistance heating member 11
3 is composed of a heating element sheet in which a resistance member 117 is fixed in advance on an insulating film material 114, so that when the heating roller 110 is assembled, the resistance heating member 113 is attached to the inner peripheral surface of the roller body 111. It also has the advantage that the work of fixing it to the camera can be easily performed.

[0006]

However, when assembling the resistance heating member 113 to the inner peripheral surface of the roller body 111, a heat-resistant adhesive having no adhesive action at room temperature is applied to the surface of the insulating film material 114. Is inserted into the roller body 111, and the resistance heating member 113 is pressed and contacted with the inner peripheral surface of the roller body 111 by air pressure or the like, and is adhered and fixed by heating in a high-temperature furnace. There is a problem that the step is complicated. Also,
Without performing the above-described bonding operation, the resistance heating member 11
Although it is conceivable to provide a pressing member for fixing the roller 3 to the inner peripheral surface of the roller body 111, the number of parts to be assembled is increased, and the assembling process is still complicated.

An object of the present invention is to provide a heating roller capable of facilitating an assembling process and reducing operation costs.

[0008]

Means for Solving the Problems and Effects of the Invention In view of the above problems, a heating roller according to claim 1 of the present application includes a hollow cylindrical roller main body, an insulating region, and a resistance heating element. A heat-resistant insulating sheet having a heat-generating portion region, wherein the heat-resistant insulating sheet is mounted inside the roller body in a state wound so that the heat-generating region is arranged inside the insulating portion region. It is characterized by being performed.

The insulating portion region is formed from a part of the heat-resistant insulating sheet, and the heat-generating portion region is formed by disposing a resistance heating element on the heat-resistant insulating sheet. The resistance heating element is formed by forming a conductive foil film of, for example, stainless steel, aluminum, or copper into a predetermined pattern. The resistance heating element generates heat when supplied with power from the outside. Then, the roller body is heated by the heated resistance heating element so that the surface temperature thereof has a predetermined temperature distribution. The resistance heating element is insulated from the roller body by the insulating section wound around the outside.

According to the above configuration, since one heat-resistant insulating sheet has both the insulating function of the insulating portion area and the heat generating function of the heat generating portion area, it is wound and inserted when it is mounted inside the roller body. Just by doing so, the effect of the above function can be obtained. For this reason, the effect that the assembling process is simplified and the working efficiency is improved can be obtained.

A heating roller according to a second aspect of the present invention is characterized in that the insulating region and the heat generating region each have a length substantially equal to or longer than the inner circumference of the roller body. That is, in order to uniformly heat the entire inner periphery of the roller main body, the heat generating portion region has a length that at least substantially makes one round of the inner circumference of the roller main body. In order to ensure insulation between the rollers, the insulating portion region is also configured to have a length which is at least substantially equal to the inner circumference of the roller body.

Since the insulating effect differs depending on the material, thickness, etc. of the heat-resistant insulating sheet, the insulating portion region has a length sufficient to obtain the required insulating effect by being wound and forming a layer. Shall have. According to the above configuration, a heating roller having a uniform temperature distribution and excellent safety can be provided. Also, if the resistance heating element is provided only on one surface of the heat-resistant insulating sheet, and the heat-resistant insulation sheet is disposed on the roller body with the resistance heating element inside, there is a gap between the resistance heating element and the inner peripheral surface of the roller body. Since the insulating region and the heat-resistant insulating sheet supporting the resistance heating element are interposed, and a double insulating layer is formed, the insulating effect is improved.

The heating roller according to claim 3 of the present application has a pressing means mounted inside the wound heat-resistant insulating sheet and pressing the heat-resistant insulating sheet in the direction of the inner peripheral surface of the roller body. It is characterized by. The above configuration is for pressing the wound heat-resistant insulating sheet in the direction of the inner peripheral surface of the roller body from the inside thereof. As the pressing means, means for obtaining a pressing force by foaming a foamed resin material inside, or means for obtaining a pressing force by inserting a stretchable elastic body such as silicone sponge therein, and further, a cylindrical shape Various modes can be considered, such as means for inserting a leaf spring into the inside to obtain a pressing force.

According to the above construction, the heat-resistant insulating sheet functioning as a heat-generating layer can be formed in a simpler process than in the case where the heat-resistant insulating sheet is closely adhered using an adhesive, and without causing local poor adhesion. It can be uniformly adhered to the inner peripheral surface, and a good heating state can be obtained.

According to a fourth aspect of the present invention, in the heating roller, the pressing means includes a pressing portion region provided with a thin plate-like elastic body following the heat generating portion region of the heat resistant insulating sheet. The roller is mounted in the roller body in a state of being wound so that the pressing portion region is disposed on the innermost side.

In the above configuration, a pressing portion region in which pressing means is further provided is formed on the heat-resistant insulating sheet.
As the pressing means, a thin plate-like elastic body having a length that can be wound into a cylindrical shape is used. The elastic body is attached on the heat-resistant insulating sheet so that the elastic body is disposed on the innermost side when the heat-resistant insulating sheet is wound.

According to the above configuration, since one heat-resistant insulating sheet has not only the insulating function of the insulating portion region and the heat generating function of the heat generating portion region but also the pressing function of the pressing portion region, the sheet is wound. Then, simply by inserting it into the roller body, mounting is completed. For this reason, the effect that the assembling process is further simplified and the working efficiency is extremely improved can be obtained.

If a material having excellent heat conductivity is used as the elastic body, even if the resistance heating element disposed outside thereof has a locally high temperature for some reason, The generated heat is received by a part of the elastic body, is uniformly dispersed throughout the elastic body, and saturates. Therefore, the heating roller itself does not suffer from temperature unevenness due to the local heat generation, and the outer surface of the heating roller can maintain a stable heated state. In this case, even if a conductive metal is used as the elastic body, the insulating material is interposed between the elastic body and the resistance heating element because the film material of the heat-resistant insulating sheet that supports them is provided. It is guaranteed, and no short circuit occurs.

A heating roller according to a fifth aspect of the present invention is characterized in that the elastic body is formed of the same material as the resistance heating element. According to the above configuration, the elastic body and the resistance heating element are integrally formed by attaching a thin plate of the material on the heat-resistant insulating sheet and performing an etching process or the like on the thin plate. As a result, the effect that the working efficiency is further improved can be obtained.

According to a sixth aspect of the present invention, there is provided a heating roller, comprising: a roller body having a hollow cylindrical shape; a heating section provided with a resistance heating element; and a pressing member provided with a thin plate-like elastic body following the heating section. And a heat-resistant insulating sheet having a portion region, wherein the heat-resistant insulating sheet is mounted inside the roller body in a state of being wound so that the pressing portion region is arranged at the innermost side. I do.

According to the above configuration, one heat-resistant insulating sheet has both a heat-generating function by the heat-generating portion area and a fixing function by the pressing-portion region. When the sheet is mounted inside the roller body, it is wound and inserted. Just complete the installation. For this reason, assembling steps are simplified and work efficiency is improved as compared with the work of mounting the heat generating member and the pressing member separately as in the related art. As a result, the effect that the working cost can be reduced is obtained.

The configuration of the heat-resistant insulating sheet may be, for example, a mode in which the insulating portion region is omitted from the configuration of the heat-resistant insulating sheet according to the fourth aspect. This configuration is particularly effective when the heat-resistant insulating sheet itself supporting the resistance heating element has a sufficient insulating effect.

In other words, the above-described configuration has a configuration in which the resistance heating element is provided only on one surface of the heat-resistant insulating sheet, and the heat-resistant insulation sheet is disposed on the roller body with the resistance heating element positioned inside. Therefore, a heat-resistant insulating sheet that supports the resistance heating element is interposed between the resistance heating element and the inner peripheral surface of the roller body. Since the heat-resistant insulating sheet supporting the resistance heating element has a sufficient insulation effect, the insulation effect between the resistance heating element and the roller body is guaranteed.

According to the above configuration, since the heat-resistant insulating sheet includes only the heat-generating portion region and the pressing portion region, the size of the heat-resistant insulating sheet can be reduced. Therefore, while making the heat-resistant insulating sheet is easy,
The effect of further simplifying the process of assembling the inside of the roller body and improving the working efficiency is obtained.

According to a seventh aspect of the present invention, in the heating roller according to the sixth aspect, the heat generating portion region and the pressing portion region are each substantially equal to or longer than the length of the inner circumference of the roller body. Having a length of

That is, in order to uniformly heat the entire inner periphery of the roller body, the heat-generating region has a length that at least substantially makes one round around the inner periphery of the roller body. In order to press and fix the inner circumference of the roller body with a uniform pressing force, the pressing portion region is also configured to have a length that at least substantially goes around the inner circumference of the roller body.

According to the above configuration, a heating roller having a uniform temperature distribution and excellent safety can be provided.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings in order to further clarify the embodiments of the present invention. FIG. 1 is a schematic cross-sectional view of a printer as an image forming apparatus configured using the heating roller according to the present embodiment,
FIG. 2 is a side cross-sectional view of a fixing device configured using the heating roller, FIG. 3 is a front cross-sectional view of the fixing device, and FIG.
FIG. 3 shows a cross-sectional view of the heating roller.

As shown in FIG. 1, a laser printer P according to the present embodiment has a configuration in which a fixing device 10, an image forming mechanism 20, a paper supply mechanism 30, a paper discharge mechanism 60, and the like are housed in a housing 70. Have been. After the fixing device 10 forms an image made of toner (hereinafter, referred to as a toner image) on paper as a recording medium in the image forming mechanism 20,
The paper is heated while being transported downstream in the paper transport direction,
The toner is fused or softened on the paper to fix the toner image on the paper.

As is well known, the image forming mechanism 20 includes:
It performs an electrophotographic image forming process, and includes a drum type electrophotographic photosensitive member, a charger, an exposure device, a developing device, a transfer device, a static eliminator, and the like. When forming a toner image on paper,
A charge is given to the surface of the drum type electrophotographic photosensitive member,
A light from a laser light source is projected on the surface to form an electrostatic latent image, the electrostatic latent image is developed with toner, and the toner image is transferred to a sheet conveyed from an upstream side to a downstream side in a sheet conveying direction. Perform the following processing.

A paper supply mechanism 30 is provided upstream of the image forming mechanism 20 in the paper transport direction. The paper supply mechanism 30 includes a paper cassette unit 4 in which paper is stacked and stored.
0, or the paper is taken in from one of the manual paper feed units 50 that can supply the paper one by one, and the paper is sandwiched between rotating rollers while moving to the image forming mechanism 20 side downstream in the paper transport direction. Transport. Further, a sheet discharging mechanism 60 is disposed downstream of the fixing device 10 in the sheet conveying direction. The paper discharge mechanism 60 conveys the paper on which the toner image has been fixed in the fixing device 10 to a tray on the upper part of the main body.

Next, the fixing device 10 will be described in detail. As shown in FIG. 2, the fixing device 10 includes a heating roller 1 and a pressure roller 2 paired with the heating roller. As will be described in detail later, the heating roller 1 is formed by fixing a heating element on the inner peripheral surface side of a cylindrical body made of aluminum. The pressure roller 2 is formed by providing heat-resistant silicone rubber around a metal shaft.

The heating roller 1 and the pressure roller 2 are arranged in parallel with their outer peripheral surfaces in contact with each other. The pressure roller 2 is rotatably supported by a movable bearing 11, and the movable bearing 11 is urged by a spring 16. As a result, the pressure roller 2 is in pressure contact with the heating roller 1.

Paper guides 12 and 18 are provided near the heating roller 1 and the pressure roller 2. The paper guide 18 is a member that guides the paper S transported from the image forming mechanism 20 on the upstream side in the paper transport direction to the pressure contact surfaces of the heating roller 1 and the pressure roller 2. The sheet guide 12 is a member that guides the sheet S, which is sandwiched between the pressure contact surfaces of the heating roller 1 and the pressure roller 2 and is sent with the rotation of both rollers, to the sheet discharge mechanism 60 further downstream in the sheet conveying direction. It is.

A cover 15 provided with a paper guide 19 is disposed above the heating roller 1 in order to prevent the sheet S from coming into contact with the heated heating roller 1 again. An overheat temperature sensor 26 is mounted on the cover 15. The overheat temperature sensor 26 is composed of a temperature fuse or a thermostat,
When an abnormal overheating of the heating roller 1 occurs due to a runaway of the control device or the like, the heating roller 1 detects the abnormal overheating and shuts off the power supply circuit. The fixing device 10 is provided with a temperature sensor (not shown) for detecting the surface temperature of the heating roller 1 separately from the overheating temperature sensor 26. The temperature sensor constantly monitors the surface temperature of the heating roller 1. Then, control is performed so that an appropriate temperature is maintained.

The heating roller 1 configured as described above
As shown in FIG. 3, the bearing 4 fixed to the body frame
1 and 41 rotatably supported. A driving gear 25 is mounted on one end of the heating roller 1, and a driving force from a motor (not shown) is transmitted to the driving gear 25 to rotate the heating roller 1. The drive gear 25 is formed by processing PPS (polyphenylene sulfide resin) having excellent heat resistance, and the bearing 41 is formed by molding a composite resin material in which carbon is dispersed as a conductive filler in PPS serving as a matrix. It is processed and has heat resistance and conductivity that do not soften up to about 250 ° C. to 260 ° C.

As long as the heating roller 1 is used under normal temperature conditions (about 200 ° C.), the bearing 41 and the drive gear 25 do not deform. The heating roller 1 is electrically connected to grounded metal parts and the like via the conductive bearings 41, 41, thereby preventing the heating roller 1 from being charged. ing.

Further, sliding contact mechanisms 75, 75 are formed at both ends of the heating roller 1. The sliding contact mechanism 75 includes a rotating electrode member 71 fixed to the heating roller 1 and rotating integrally with the heating roller 1, and a stationary electrode member 72 fixed to the main body frame and in contact with the rotating electrode member 71. The rotating electrode member 71 is electrically connected to a current-carrying terminal of a sheet-like heating element, which will be described later, fixed to the inner peripheral surface side of the heating roller 1. Further, the stationary electrode member 72 is in pressure contact with the rotating electrode member 71 with elastic deformation. As a result, the two electrode members slide while maintaining the contact even when the heating roller 1 rotates, and can maintain a state in which both are electrically connected. In addition, electric power is supplied to the heating element through the sliding contact mechanisms 75, 75.

As shown in FIG. 4, the heating roller 1 itself has a hollow cylindrical aluminum roller body 3 as a base material, and has an adhesion preventing layer 8 on the outer peripheral surface of the roller body 3.
Is formed, and a heat-resistant insulating sheet 13 is wound and mounted on the inner peripheral surface of the roller body 3 to form a heat generating layer.

The adhesion preventing layer 8 is provided to prevent the toner on the recording medium from adhering to the surface of the heating roller 1 during the fixing process. It is formed by coating a fluororesin-based material having excellent moldability, and has a thickness of about 10 to 30 μm.

Heat-resistant insulating sheet 13 for forming the heating layer
As shown in FIG. 5, a pressing portion region X, a heating portion region Y, and an insulating portion region Z are arranged on an insulating base material 14 made of a polyimide resin film material. I have. A rectangular elastic body 6 formed of a stainless steel thin plate is attached to the pressing portion region X,
When receiving a deformation force, the elastic body 6 has a property of returning to its original shape by the elastic force.

A resistance heating element 17 made of a stainless steel thin plate is adhered to the heating section area Y. The resistive heating element 17 is connected to both ends of the pattern section 17a functioning as a heating element and the pattern section 17a, and a part of the first heating terminal section 17b extending to the pressing section area X, and The pattern portion 17a generates heat when a current flows between the two current-carrying terminal portions 17b and 17c.

The resistance heating element 17 adjusts the temperature distribution of the amount of heat generated by the shape, cross-sectional area and the like of the pattern in the pattern portion 17a. That is, by utilizing the fact that the calorific value is large in the region with a small cross-sectional area and small in the region with a large cross-sectional area, the calorific value is adjusted so that the temperature distribution on the outer peripheral surface of the heating roller 1 becomes uniform. doing. In the present embodiment, the cross-sectional area of the pattern is
The heating roller 1 is heated as it approaches the both ends of the heating roller 1 from the pattern A to the pattern D shown in FIG. This is because both ends of the heating roller 1 have a larger amount of heat radiation than the central portion, and if the heat generation amount is the same over the entirety, the surface temperature tends to be lower near the both ends than at the central portion. is there.

The elastic body 6 and the resistance heating element 17
Is integrally formed by attaching a stainless steel foil film to the insulating base material 14 and performing an etching process on the stainless steel. For this reason, the heat-resistant insulating sheet 13 can be configured simply and quickly as compared with a method in which each of the elastic body 6 and the resistance heating element 17 is individually formed and attached to the insulating base material 14.

The insulating region Z is a rectangular region formed by a part of the insulating base material 14. As shown in FIG. 4, the heat-resistant insulating sheet 13 thus configured is
It is mounted on the inner peripheral surface of the roller body 3 in a wound state.
The winding of the heat-resistant insulating sheet 13 is performed such that the pressing portion region X is the innermost portion, and the heating portion region Y and the insulating portion region Z are sequentially layered outside the pressing portion region X.

At this time, the elastic body 6 of the pressing portion region X arranged on the innermost layer is formed by the heat generating portion regions Y,
The configuration is such that the insulating portion region Z is sandwiched between the roller body 3 and pressed and held. In addition, the above-mentioned pressing part area X,
The heat generating section Y and the insulating section Z are formed so as to be at least equal to or longer than the inner circumference of the roller body 3 when wound.

As described above, one heat-resistant insulating sheet 13
Has both the insulating function of the insulating portion area Z, the heat generating function of the heat generating portion region Y, and the pressing and fixing function of the pressing portion region X. The installation is completed simply by winding and inserting. For this reason, the assembling process is simplified, and the working efficiency is extremely improved.

The stainless steel used for the elastic body 6 is made of a thin plate having good conductivity, and therefore has excellent heat conductivity. Therefore, even when the temperature of the resistance heating element 17 disposed on the outside of the resistance heating element 17 locally rises, the generated heat is received by a part of the elastic body 6 and is uniformly distributed throughout the elastic body 6. Disperses and saturates. For this reason, the temperature unevenness due to the local heat generation does not occur on the heating roller 1 itself, and the outer surface of the heating roller 1 can maintain a stable heating state.

Further, as described above, the resistance heating element 17 and the elastic body 6 correspond to the insulating base material 1 constituting the heat-resistant insulating sheet 13.
4 is provided only on one surface of the heat-resistant insulating sheet 13.
Is mounted on the inner peripheral surface of the roller body 3 with the resistance heating element 17 and the elastic body 6 inside. Therefore, the resistance heating element 17
And the inner peripheral surface of the roller body 3, the insulating region Z
And the insulating base material 14 supporting the resistance heating element 17, and a double insulating layer is formed, so that the insulating effect is improved. Similarly, the insulating base material 14 supporting the elastic body 6 is interposed between the elastic body 6 and the resistance heating element 17, and an insulating layer is formed, so that the insulating effect is ensured.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various embodiments can be adopted without departing from the gist of the present invention. For example, in this embodiment, a laser printer is used as an image forming apparatus. However, it is needless to say that a copying machine, a facsimile, and other image forming apparatuses may be used. The image forming method is not limited to the electrophotographic method using a toner, but may be a hot melt ink jet method using a heat-meltable ink. In addition, although the material of the roller body 3 of the heating roller 1 is made of aluminum, any material having good thermal conductivity may be used regardless of whether it is a conductor or a non-conductor.

In the above embodiment, the elastic body 6 and the resistance heating element 17 are integrally formed from a single stainless steel thin plate. However, it is needless to say that they may be formed separately. . The material of the elastic body 6 and the resistance heating element 17 is not limited to stainless steel, but copper, aluminum, or another conductive material may be used.

Further, when the insulating base material 14 has a certain thickness and elastic properties, the elastic body 6 is omitted,
The heat-resistant insulating sheet 1 is partially covered by the insulating base material 14.
A configuration in which the roller 3 is fixed in the inner circumferential direction of the roller body 3 may be adopted. When the insulating base 14 has a sufficient insulating effect, the insulating region Z may be omitted. In this case, since the insulating base material 14 supporting the resistance heating element 17 is interposed between the resistance heating element 17 and the inner peripheral surface of the roller body 3, the resistance heating element 17 and the roller body 3 This is because the insulating effect between them is guaranteed.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a laser printer having a heating roller as an embodiment.

FIG. 2 is an enlarged sectional view of a fixing device using a heating roller according to the embodiment.

FIG. 3 is a view taken in the direction of arrows AA in FIG. 2;

FIG. 4 is a sectional view of a heating roller according to the embodiment (BB in FIG. 3);
FIG.

FIG. 5 is an explanatory view of a heat-resistant insulating sheet of a heating roller of an example.

FIG. 6 is an explanatory view schematically showing a conventional heating roller.

FIG. 7 is an explanatory view schematically showing a main part of a conventional heating roller.

[Explanation of symbols]

1. Heating roller 3. Roller body 6.
Elastic body, 8: anti-adhesion layer, 10: fixing device, 13: heat-resistant insulating sheet, 13: heat-resistant insulating sheet, 14: insulating base material, 17: resistance heating Body, 17a: Pattern part, 17b: First energizing terminal part, 17b: Both energizing terminal parts, 17c
..Second energizing terminal portion, 20 ... image forming mechanism, P
... Laser printer, X ... Pressing area, Y
..Heat generating area, Z ... Insulating area

Claims (7)

[Claims] 1. A heat-resistant insulating sheet having a hollow cylindrical roller body, an insulating section area, and a heating section area provided with a resistive heating element, wherein the heat-resistant insulating sheet has a heat-generating section area that is A heating roller for fixing, wherein the heating roller for fixing is mounted inside the roller main body in a state of being wound so as to be disposed inside the insulating portion region. 2. The insulating section area and the heat generating section area,
2. The fixing heat roller according to claim 1, wherein each of the heat rollers has a length substantially equal to or longer than an inner circumference of the roller body. 3. The roller according to claim 1, further comprising a pressing unit mounted inside the wound heat-resistant insulating sheet and pressing the heat-resistant insulating sheet in the direction of the inner peripheral surface of the roller body. Item 3. A heating roller for fixing according to Item 2. 4. The pressing means comprises a pressing portion region provided with a thin plate-like elastic body following the heat generating portion region of the heat resistant insulating sheet, wherein the heat resistant insulating sheet has the pressing portion region at the innermost side. 4. The fixing heat roller according to claim 3, wherein the heat roller is mounted inside the roller body in a state of being wound so as to be arranged. 5. The fixing heating roller according to claim 4, wherein the elastic body is formed of the same material as the resistance heating element. 6. A heat-resistant insulating sheet having a hollow cylindrical roller main body, a heating section area provided with a resistance heating element, and a pressing section area provided with a thin plate-like elastic body following the heating section area. The fixing heat roller, wherein the heat-resistant insulating sheet is mounted inside the roller body in a state where the heat-resistant insulating sheet is wound so that the pressing portion region is disposed on the innermost side. 7. The heating section area and the pressing section area,
7. The fixing heat roller according to claim 6, wherein each of the heat rollers has a length substantially equal to or longer than an inner circumference of the roller body.