JP4355165B2 - Endless belt - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a fixing device having an endless belt, and more particularly to a fixing device used in an electrophotographic process image forming apparatus such as a copying machine, a printer, and a facsimile machine.
[0002]
[Prior art]
FIG. 12 is a diagram showing an outline of a fixing device using only rollers.
FIG. 13 is a diagram showing an outline of a fixing device having a belt.
In both figures, reference numeral 101 denotes a heating roller, 102 denotes a pressure roller, 103 denotes recording paper, 104 denotes a toner image, 105 denotes an endless belt, 106 denotes a driving roller, and 107 denotes heating means.
[0003]
As the fixing device, as shown in FIG. 12, a heating unit 107 is incorporated, and a heating roller 101 and a pressure roller 102 provided with a driving unit are used to heat the unfixed toner 104 on the recording paper 103 and at the same time, the heating roller 101. And a “roll nip fixing device” that conveys while applying pressure generated between the pressure roller 102 and the roll nip fixing device as shown in FIG. 13 and a driving roller 106 that combines a fixing belt 105, a tensioner, and driving means. A belt which is newly provided and applies a pressure generated between the fixing belt 105 and the pressure roller 102 incorporating the heating means 107 to heat and convey the unfixed toner 104 on the recording paper 103 like the roll nip fixing device. Two of “nip fixing devices” are mainstream.
[0004]
Up until now, the former roll nip fixing device has been mainly used. However, a belt that can set the nip width (pressurization time) to be larger from the viewpoint of compatibility with color machines that melt and mix four colors and the improvement in image quality associated with digitization. Nip fixing devices are becoming widespread.
It is well known that the unfixed toner 104 layer of a color machine is formed thicker than monochrome (single color) and requires more time for melting and pressing.
[0005]
FIG. 14 is a sectional view showing an outline of the belt nip fixing device.
FIG. 15 is a sectional view showing an outline of the roll nip fixing device.
FIG. 16 is a perspective view showing an outline of the belt nip fixing device.
The belt nip fixing device has a larger winding angle of the fixing belt 105 around the pressure roller 102 as shown in FIG. 14, and can set the nip width larger than the roll nip fixing device of FIG. However, as shown in FIG. 16, there is a problem that the heat capacity is large and the temperature rise time is longer than that of the roll nip fixing device because the fixing belt 105 and the driving roller 106 are increased as compared with FIG. The configuration is complicated and the cost is much higher.
[0006]
FIG. 17 shows an example of the external heating means.
FIG. 18 is a diagram showing another example of the external heating means.
In both figures, reference numeral 107 ′ denotes an external heating roller, 107 ″ denotes electromagnetic induction heating means, and S denotes transfer paper.
In order to shorten the temperature rising time of the belt nip fixing device, an external heating roller as shown in FIG. 17 is added and a heat source addition method using electromagnetic induction (IH) as shown in FIG. 18 is also changed.
In either case, since it is difficult to reduce the cost, it is necessary to improve the endless belt 105 itself that has a short heating time and does not increase the cost.
[0007]
FIG. 19 is a diagram showing the configuration of the belt.
In the figure, reference numeral 108 denotes a base material layer, and 109 denotes a surface layer.
The endless belt 105 is base layer is a core part of the belt-type fixing device, nickel, carbon steel, those utilizing spliced ones or electroforming metal sheet such as stainless steel, or a heat-resistant resin (such as polyimide ), And a surface layer 109 is formed of a heat-resistant release layer (fluorine resin, high release silicone rubber) in consideration of the pressure of the unfixed toner 104 and high release properties.・ Tubes etc. are covered, but all of these are difficult to shorten the heating time and have problems with strength and dimensional stability. Or the belt circumference may change and wrinkles may occur, causing abnormal conveyance and abnormal images. As an example, the surface layer 109 in the figure shows a case where a layer 109a of a fluororesin PFA having a constant friction coefficient is stacked on a heat-resistant silicone rubber layer 109b. The vertical relationship between the two layers may be reversed. Further, only one of the layers can be used.
[0008]
Advantages and disadvantages of polyimide resin and nickel, which are frequently used for the base material layer 108, are described below.
Polyimide base material has moderate wear resistance and flexibility, is not easily affected by friction during rotation, has moderate adaptability to bending, and is not easily affected by the difference in curvature of the heating roller 101 diameter However, since the heat capacity is relatively large and the thermal conductivity is low, it is difficult to further shorten the temperature rising time.
On the other hand, the nickel base has the advantage that the temperature rise time is relatively short because the specific heat is small and heat conduction is good, but it is rigid and poor in flexibility, and is affected by the difference in curvature of the heating roller 101 diameter. Cannot be adapted, and problems such as durability and noise due to friction remain.
[0009]
Aiming to solve the problems of both base materials, there is one that uses a mesh body for the base material layer 108 of the endless belt 105 to reduce the heat capacity corresponding to the void ratio and the volume difference, and to improve the flexibility against bending and expansion / contraction ( For example, see Patent Document 1.)
FIG. 20 is a diagram showing the difference in the base material layer of the belt.
In the figure, reference numeral 110 denotes a mesh body.
Many mesh bodies 110 are made by weaving resin or metal fibers with a loom, and the surface layer 109 is formed with a film of silicon rubber or the like as in the prior art, so that it looks like the conventional endless belt 105 in appearance. However, the mesh body has the following disadvantages.
[0010]
FIG. 21 is a diagram based on an electron micrograph of a mesh body.
In the fiber weaving (meshing), the thickness of the surface layer 109 is required to eliminate the uneven step caused by the crossing of the fiber warp and weft yarns shown in the figure, compared to the surface layer 109 of the conventional polyimide resin or nickel base material. Is also formed thick. As a result, the number of rubber layers having a large heat capacity and poor thermal conductivity increases, and the effect of reducing the heat capacity of the mesh body 110 is halved.
Furthermore, when heat conduction is taken into consideration, the fiber constituting the mesh body 110 is preferably a metal fiber rather than a resin fiber. However, like the nickel base material, it is fragile to flexibility and bending, and it is particularly difficult to reduce the diameter. .
[0011]
FIG. 22 is a view for explaining heat radiation from the roller end.
FIG. 23 is a diagram for explaining an abnormal image at the roller end.
Regardless of the endless belt of any of the above-mentioned base materials, both side surfaces of the heating roller 101 are largely open for the convenience of inserting a halogen heater as the heating means 107, so that heat loss at both ends is caused as shown in FIG. If the measure is large and no particular measures are taken, the temperature distribution of the fixing belt surface tends to follow this distribution in a certain distance range from the left and right ends with respect to the central portion. Hereinafter, this range at both ends of the roller is referred to as a temperature drop region for convenience.
The temperature drop at the left and right ends affects the fixability, and when it is extremely low, an abnormal image called a cold offset is produced as shown in FIG.
The above problem can be solved by adjusting the light emission distribution of the halogen heater itself (increasing the left-right efficiency), but the temperature rise time is sacrificed as the distribution is leveled.
In order to maintain the temperature rising time, it is necessary to increase the output (wattage) or to increase the number, which goes against the flow of cost reduction and power consumption reduction.
[0012]
In consideration of the above-described thermal conductivity and heat capacity, the entire substrate is made as thin as possible. As a result, rigidity and strength are weakened, and both end portions of the endless belt are liable to crack and have a risk of breakage.
FIG. 24 is a diagram for explaining a belt having a function of preventing deviation at the end.
In the figure, reference numeral 110a denotes a reinforcing material.
In order to prevent cracks, as shown in the figure, measures are taken such as adhering a reinforcing material 110a having a function of preventing the end portion from shifting toward the end, for example, a silicon rubber ring on both sides of the belt. By this rubber ring, the belt falls into the stepped portion 106a at the end of the roller 106, and abuts against the side surface of the roller end, thereby fulfilling the function of preventing deviation. However, this method mainly uses heat-resistant rubber and is constructed by using an adhesion method, which greatly increases the cost.
As the demand for high image quality rises, an “endless belt” that is inexpensive and has a short heating time is awaited, reducing the weaving steps, promoting heat transfer, uniform temperature distribution, and flexibility. Development of “belt” is required. Even as a heat source, the use of inexpensive halogen heaters cannot be deferred, and it is essential to reduce power consumption in consideration of the environment.
[0013]
[Patent Document 1]
JP 2002-251088 A (3rd, 4th page, FIG. 5)
[0014]
[Problems to be solved by the invention]
Providing a mesh body with both flexibility and heat transfer and with few weave steps.
An inexpensive heat source that provides a uniform temperature distribution method that does not require additional components.
Provided is a heat-resistant endless belt which does not require an end reinforcement and has high rigidity and high durability.
[0015]
[Means for Solving the Problems]
According to the first aspect of the present invention, in an endless belt having a fiber layer composed of warp and weft perpendicular to each other and having a gap as a base material, the gap in the fiber layer in the temperature decreasing region near both ends in the width direction of the endless belt. The rate is larger than the porosity of the central part .
According to a second aspect of the present invention, in the endless belt according to the first aspect, the porosity of the fiber layer in the temperature lowering region is set so as to increase toward the end .
According to a third aspect of the present invention, in the endless belt according to the first or second aspect, the fiber layer is configured to have better thermal conductivity in the width direction than in the endless direction .
According to a fourth aspect of the present invention, in the endless belt according to any one of the first to third aspects, at least a part of the warp yarns oriented in the width direction of the endless belt has a thermal conductivity of 31.2 W / mK or more. It is composed of a certain highly heat conductive metal fiber .
[0016]
The invention according to claim 5 is the endless belt according to claim 3 or 4, wherein the fibers other than the metal fibers of the fiber layer have a melting point of 260 ° C or higher.
In the invention of claim 6, in the endless belt according to any one of claims 1 to 5, the endless belt is a cylindrical woven fabric having a circumference equal to the circumference of the endless belt , It is woven by a bag weaving method .
In the invention of claim 7, in an endless belt according to any one of claims 1 to 6, wherein the endless belt, you characterized by bending both ends of the endless belt is facilities.
[0018]
According to an eighth aspect of the present invention, the fixing belt according to any one of the first to seventh aspects includes the fiber layer, and a heat-resistant surface having a smooth surface with a thickness equal to or greater than the thickness of the fiber layer. it characterized in that the addition of sexual material as the surface layer.
[0019]
The invention of claim 9 is characterized by a fixing device using the fixing belt of claim 8 .
[0020]
In the invention of claim 10, said image forming apparatus using the fixing device according to claim 9.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a sectional view showing the overall configuration of an image forming apparatus using a fixing device according to the present invention.
In the figure, reference numeral 1 is a photosensitive member, 2 is a charging device, 3 is a cleaning device, 4 is a developing device including a developing roller 4a, 5 is a transferring device, 6 is a fixing roller, 8 is a fixing belt, 9 is a belt driving roller, Reference numeral 45 denotes a pressure roller. Other symbols are directly cited in the description.
[0022]
The photosensitive member 1 rotates in the direction of an arrow in the figure, and a latent image on the photosensitive member 1 is visualized by supplying a charging unit 2, a cleaning device 3, a laser beam L and toner by a laser optical system around the photosensitive member 1. A developing device 4 and a transfer means 5 are disposed. A toner supply unit 14 is provided in the vicinity of the developing device 4.
The transfer paper P is set in a detachable paper feed cassette 17 disposed on the lower side, and is pressed against the paper feed roller 19 by a spring force (not shown).
[0023]
When a command is issued from a control unit (not shown) and the paper feed roller 19 rotates, the uppermost paper in the paper feed cassette 17 is conveyed to the downstream registration roller 20 while being prevented from being double-fed by a separation pad or the like. Is done. Then, timing is taken so as to synchronize with the image on the photoreceptor 1, and the sheet is sent out toward the transfer means 5. The transfer paper P obtained from the photosensitive member 1 by the transfer means 5 is further conveyed to the belt fixing device 11 where the toner image is fixed by the heat treatment of the unfixed toner.
Thereafter, the transfer sheet P on which the image has been fixed is discharged and placed on the discharge tray portion 93 from the discharge port 22 by the discharge roller 21. In the figure, reference numeral 90 denotes an automatic document feeder, 91 denotes a scanner unit, and 92 denotes the above-described image forming unit.
The toner on the photoreceptor 1 after the toner image transfer is collected by the cleaning device 3. The collected toner is returned to the developing device 4 and repeatedly used for image formation.
[0024]
FIG. 2 is a sectional view showing an embodiment of a belt fixing apparatus according to the present invention.
In the figure, reference numeral 51 is a fixing device, 52 is a fixing belt, 53 is a heating roller, 54 is a fixing roller, 55 is a pressure roller, 58 is a thermistor, 59 is a metal core, 60 is an elastic layer, and 61 is a guide. Show.
The illustrated fixing device 51 includes a heating roller 53 that stretches an endless fixing belt 52 that conveys transfer paper, a fixing roller 54, and a heating roller 53 that is disposed to face the fixing roller 54 via the fixing belt 52. It comprises a pressure roller 55 and a heating roller 53 having a heater on the surface. In order to apply a predetermined tension to the fixing belt 52, the heating roller 53 is urged in a direction to separate the heating roller 53 from the fixing roller 54 as indicated by an arrow a by an elastic body (not shown) such as a spring. A thermistor (not shown) is disposed on the outer periphery of the fixing belt 52 in contact with the fixing roller 54, and detects the temperature at the nip outlet.
[0025]
A thermistor 58 is also disposed on the fixing belt 52 on the heating roller 53 side to detect the temperature of the fixing belt 52. The fixing roller 54 includes a metal core 59 and a heat-resistant porous elastic body layer 60 that covers the metal core 59, and the metal core 59 is rotatably supported by a non-illustrated non-illustrated member at the shaft end. .
The pressure roller 55 is urged by an elastic body (not shown) such as a spring so as to come into pressure contact with the fixing roller 54 as indicated by an arrow b. The pressure roller 55 is pressed against at least the fixing roller 54 so as to form a nip. The guide 61 guides the transfer paper to be fixed toward the fixing nip. The pressure roller 55 is a core metal surface with a PFA coating.
[0026]
FIG. 3 is an enlarged sectional view showing the structure of the fixing belt of the present invention.
In the figure, reference numeral 62 denotes an outer layer, and 63 denotes a fiber layer forming a mesh body.
The fiber layer 63 provides strength and dimensional stability, and as shown in the drawing, the outer layer 62 made of a heat-resistant material such as a fluororesin and heat-resistant rubber or heat-resistant resin is thicker than the fiber layer 63 so that the surface becomes a smooth surface. And heat-resistant material are integrated, so releasability can be ensured even if there is wear. Silicon resin may be added instead of or in combination with the fluororesin.
[0027]
Figure 4 is a schematic diagram showing the textiles direction Designation of the fixing belt.
In the figure, reference numeral 111 denotes a fiber extending in the width direction of the fixing belt (axial direction of the driving roller), and this is called a warp for convenience. Reference numeral 112 denotes a fiber extending in the fixing belt traveling direction (circumferential direction of the driving roller: hereinafter referred to as an endless direction), which is referred to as a weft.
In the present invention, the warp yarn has the metal fiber 111a having high heat conductivity in all or a part thereof. When the metal fiber 111a is a part, the remainder uses the heat resistant resin fiber 111b. Expressions of warp and weft are for convenience and do not necessarily match warp and weft when actually woven as a woven fabric.
[0028]
5 and 6 are diagrams showing the molecular structure of polyarylate monofilament.
The heat-resistant resin fiber 111b preferably has a melting point of 260 ° C. or higher, and is a fluororesin fiber such as PTFE, FEP, ETFE, or PFA, or a liquid crystal polymer such as a polyarylate single fiber whose molecular structure is shown in FIG. A fiber, PEEK resin fiber, etc. can be used. The metal fiber 111a preferably has a thermal conductivity of 31.2 W / mK or more, and may be a fiber made of copper, phosphor bronze, stainless steel, nickel, or the like.
[0029]
By doing so, the heat capacity is reduced compared to the conventional polyimide / nickel substrate, and the temperature raising time can be shortened. Compared to the conventional mesh body using a single material, wefts are made of resin fibers and all or part of the warp yarns are made of metal fibers, improving the flexibility (flexibility) during rotation and endlessly. towards the width direction than the direction the better the heat conductivity, it is possible to further heat transfer enhancement in the width direction.
[0030]
Figure 7 is a schematic diagram showing a general method for producing Fixing belt substrate.
This production method is a kind of weaving method of fabrics and is a known production method based on a technique called bag weaving. This method will be briefly described.
A number of warp yarns 111 (including metal fibers 111a and heat-resistant resin fibers 111b as required) corresponding to the belt circumference are arranged in a cylindrical shape sequentially when weaving the bag, and weft yarns are inserted from one end (this We will make a cylindrical fabric (called weft driving). Even if the belt has the required length, it continues to make a cylindrical fabric without stopping. When a sufficiently long cylindrical woven fabric is formed, it is cut off from the apparatus and divided into individual endless belts. In this way, a mesh-like endless belt that can be used as a fixing belt substrate is obtained.
[0031]
Since the fixing belt according to the present invention is an integrated member having no joint or step due to welding as in a conventional metal belt, the strength is stabilized at each position of the belt. At the same time, the absence of a step leads to a reduction in the surface layer thickness of the rubber layer, which hinders temperature rise, and can be used without losing the effect of the mesh body. In addition, the use of bag weaving eliminates the need for processes such as welding, which can greatly reduce processing costs.
[0032]
The divided individual endless belts can be used as fixing belt base materials by impregnating them with resins as they are, but when divided, the end of the cylinder may be bent, resulting in lack of stability. Therefore, heat treatment for stabilization as described below is preferably performed.
That is, a constant-length heat treatment process in which a cylindrical body having a diameter corresponding to the cylindrical diameter of the cylindrical fabric is inserted as a jig so that the entire length of the cylindrical endless belt passes and is left in a heating furnace at a predetermined temperature for a predetermined time. Apply.
[0033]
FIG. 8 is a view for explaining post-processing of an endless belt.
In the figure, reference numeral 121 denotes a driving roller that also serves as a tension roller, 122 denotes a heating roller, 123 denotes a heater, and 124 denotes a rolling roller.
FIG. 9 is a schematic diagram showing the state of the fiber before and after post-processing.
In the present invention, the post-processing shown in FIG. 8 is applied to the mesh endless belt obtained in FIG. 7 or the mesh endless belt subjected to constant length heat treatment.
That is, the mesh endless belt is attached to a post-processing apparatus having a belt driving device and a pressure device similar to the fixing device. The mesh endless belt 110 is stretched between a driving roller 121 having a tension function and a heating roller 122. The heating roller 122 is heated to a predetermined temperature by the heater 123. The rolling roller 124 is pressed against the heating roller 122 from the outside of the mesh endless belt 110 with a predetermined pressure, and is rotated along the belt.
[0034]
Due to the heat and pressure at this time, the intersecting portion of the warp and weft is mutually compressed and changed from the state of the fiber shown in FIG. 9 (a) to the state of the fiber shown in FIG. 9 (b). The thickness is reduced.
Such a step reduction leads to a reduction in the surface layer thickness of the rubber layer, which hinders temperature rise, and can be used without losing the effect of the mesh body.
[0035]
Figure 10 is a schematic diagram for explaining the implementation of the invention.
In this embodiment, with respect to the axial direction of the drive roller in the use state, the interval between the wefts is changed so that the middle is dense and the both ends are rough.
As described above, both ends of the heating roller in relation to the heater, since in a relaxed, especially if some action is not taken, the range of distance from the thus ends the heat-release nature is temperature drop region.
Therefore, by roughening the fiber density in the vicinity of both ends of the belt width, the void ratio is increased by increasing the void ratio, and the heat retention capability is enhanced to prevent the temperature decrease in the temperature decrease region. In the temperature distribution in the axial direction when a belt having a uniform fiber density is used, the fiber density is made dense in a range that can be regarded as almost uniform. The fiber density in the temperature drop region near both ends of the width is made rough.
[0036]
This structure can be achieved by changing the spacing between the weft threads depending on the position in the case of manufacturing by the above-described bag weaving.
The portions with coarse fiber density may all have the same density, but since there is a temperature gradient also in the temperature decrease region, gradually or stepwise from the predetermined position toward the end. The density may be roughened.
By changing the air gap ratio in this way, it is possible to make the belt surface temperature distribution on the end face side of the heating roller having a large heat loss uniform.
[0037]
FIG. 11 is a diagram for explaining another post-processing process. FIG. 1A is a side view, and FIG. For ease of understanding, the endless belt thickness is exaggerated.
This post-processing is a process of folding the end portion of the endless belt 110 in the width direction inward with a predetermined width. At the time of folding, heat treatment can be performed simultaneously to stabilize the folded portion 110b. The predetermined width for folding is a width substantially equal to the width of a rubber ring as a conventional reinforcing material. If this method is used, it is not necessary to adhere a rubber ring as a reinforcing material as in the prior art, and a shift prevention function can be obtained at low cost. In addition, the strength of the end portion where breakage is likely to occur is enhanced, durability is improved, and manufacturing costs can be reduced.
[0038]
【The invention's effect】
According to the present invention, an endless fixing belt having high fixing performance, durability, and low manufacturing cost can be obtained, and a belt nip fixing device having a short temperature rise time can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an overall configuration of an image forming apparatus using a fixing device according to the present invention.
FIG. 2 is a cross-sectional view showing an embodiment of a belt fixing apparatus according to the present invention.
FIG. 3 is an enlarged cross-sectional view showing the structure of the fixing belt of the present invention.
4 is a schematic diagram illustrating the call you in textiles direction of the fixing belt.
FIG. 5 is a view showing the molecular structure of polyarylate monofilament.
FIG. 6 is a diagram showing the molecular structure of polyarylate monofilament.
7 is a schematic diagram showing a general method for producing Fixing belt substrate.
FIG. 8 is a diagram for explaining post-processing of a fixing belt substrate.
FIG. 9 is a schematic diagram showing the state of fibers before and after post-processing.
Is a schematic diagram for explaining an implementation form of the invention; FIG.
FIG. 11 is a diagram for explaining another post-processing process;
FIG. 12 is a diagram illustrating an outline of a fixing device using only rollers.
FIG. 13 is a diagram showing an outline of a fixing device having a belt.
FIG. 14 is a cross-sectional view showing an outline of a belt nip fixing device.
FIG. 15 is a cross-sectional view illustrating an outline of a roll nip fixing device.
FIG. 16 is a perspective view showing an outline of a belt nip fixing device.
FIG. 17 is a diagram showing an example of external heating means.
FIG. 18 is a diagram showing another example of external heating means.
FIG. 19 is a diagram illustrating a configuration of a belt.
FIG. 20 is a view showing a difference in a base material layer of a belt.
FIG. 21 is a diagram based on an electron micrograph of a mesh body.
FIG. 22 is a view for explaining heat radiation from the roller end.
FIG. 23 is a diagram for explaining an abnormal image at a roller end portion;
FIG. 24 is a view for explaining a belt having a function of preventing deviation at an end portion thereof.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 51 Fixing device 52 Fixing belt 53 Heating roller 54 Fixing roller 55 Pressure roller 60 Elastic body layer 62 Outer layer 63 Fiber layer 110 Mesh endless belt 111 Warp yarn 112 Weft yarn 121 Driving roller 122 Heating roller 123 Heater 124 Rolling roller

Claims (10)

In an endless belt based on a fiber layer composed of warp yarns and weft yarns perpendicular to each other and having a gap, the void ratio of the fiber layer in the temperature decreasing region near both ends in the width direction of the endless belt Endless belt characterized by being larger . 2. The endless belt according to claim 1, wherein the porosity of the fiber layer in the temperature lowering region is set so as to increase toward an end portion . 3. 3. The endless belt according to claim 1 , wherein the fiber layer has a better thermal conductivity in the width direction than in the endless direction . The endless belt according to any one of claims 1 to 3, wherein at least a part of the warp yarns oriented in the width direction of the endless belt is a highly heat conductive metal fiber having a thermal conductivity of 31.2 W / mK or more. an endless belt which is characterized by being configured in. The endless belt according to claim 3 or 4, wherein the fibers other than the metal fibers of the fiber layer have a melting point of 260 ° C or higher. The endless belt according to any one of claims 1 to 5, wherein the endless belt is woven by a bag weaving method as a cylindrical woven fabric having a circumference equal to the circumference of the endless belt . An endless belt characterized by being a thing. In the endless belt according to any one of claims 1 to 6, wherein the endless belt is an endless belt, characterized in that bending the ends of the endless belt is facilities. The endless belt according to any one of claims 1 to 7 , wherein the fiber layer is encapsulated, and a heat-resistant material having a smooth surface with a thickness equal to or greater than the thickness of the fiber layer is added as a surface layer. A fixing belt characterized by that. A fixing device using the fixing belt according to claim 8. An image forming apparatus using the fixing device according to claim 9.

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