JP2013130634A - Endless belt, belt device, fixing device, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endless belt having a lateral end part with improved strength without causing separation of a reinforcement part.SOLUTION: The endless belt 44 stretched on a plurality of rollers and moving circularly includes an endless base layer 44a and an elastic layer 44b formed in a circumferential direction H on an outer circumferential surface 44a1 of the base layer 44a. The elastic layer 44b includes: an elastic layer body 44b1 formed on a part 44a3 other than both ends 44a2 in the width direction H on the outer circumferential surface 44a1 of the base layer 44a; and an elastic layer end part 44b2 formed on both ends 44a2 in the outer circumferential surface 44a1 of the base layer 44a and having hardness higher than that of the elastic layer body 44b1.

Description

  The present invention relates to an image forming apparatus used in an electrophotographic copying machine, a printer, or the like, and in particular, an endless belt suitable as a fixing belt for fixing a toner image transferred onto a sheet to the sheet, and the same The present invention relates to the belt device and the fixing device used.

  An image forming apparatus used in an electrophotographic copying machine, a printer, or the like includes a fixing device that fixes a toner image transferred onto a sheet to the sheet.

  FIG. 2 is a schematic configuration diagram of the conventional fixing device 200 in plan view. 3 is a cross-sectional view taken along the line III-III in FIG. 12 is a cross-sectional view taken along the line XII-XII in FIG.

  As shown in FIGS. 2 and 3, the conventional fixing device 200 includes a heating roller 43, a fixing roller 42, an endless fixing belt 100 stretched between the rollers 42 and 43, and a fixing belt 100. And a pressure roller 41 disposed so as to press the fixing roller 42. 2 and 12 indicates the width direction of each of the rollers 41, 42, 43 and the fixing belt 100.

  At both ends in the width direction H of the heating roller 43, peripheral wall portions 43c for preventing the fixing belt 100 from being biased (meandering or skewing) in the width direction H are provided. As shown in FIG. 12, the fixing belt 100 includes an endless base layer 100a, an elastic layer 100b formed on the outer peripheral surface of the base layer 100a, and a release layer 100c formed on the elastic layer 100b. .

  In the fixing device 200, as shown in FIG. 3, for example, the fixing roller 42 is rotationally driven in the direction of arrow F by a motor (not shown). Along with this rotational drive, the pressure roller 41 is driven to rotate in the direction of arrow D, and the fixing belt 100 is circulated and moved in the direction of arrow E. With this circulation, the heating roller 43 is driven to rotate in the direction of arrow G. To do.

  At that time, the fixing belt 100 circulates between the rollers 42 and 43 while being heated by the heating roller 43. Further, the fixing belt 100 circulates and moves without being biased in the width direction H because the end surface 100 d (see FIG. 12) in the width direction H abuts on the peripheral wall portion 43 c of the heating roller 43.

  In this state, when a sheet on which the toner image is transferred is carried into a pressure contact area (nip area) between the fixing belt 100 and the pressure roller 41, the sheet is transferred by the fixing belt 100 and the pressure roller 41. Pressurized and heated and sent out. By this pressurization and heating, the toner image transferred to the paper is fixed on the paper.

  In the fixing device 200, the end surface 100 d of the fixing belt 100 abuts on the peripheral wall portion 43 c of the heating roller 43, thereby preventing the fixing belt 100 from being biased.

  However, at that time, the end surface 100d of the fixing belt 100 receives a force (shifting force) from the peripheral wall portion 43c. Therefore, if the strength of the end portion 100e (see FIG. 12) in the width direction H of the fixing belt 100 is low, when the end surface 100d of the fixing belt 100 receives a shift force from the peripheral wall portion 43c, the end portion 100e of the fixing belt 100 There is a problem that problems such as buckling occur.

  Furthermore, due to this problem, the end 100e of the fixing belt 100 is damaged, or the fixing belt 100 cannot be circulated favorably.

  As a technique for solving these problems, the technique of Patent Document 1 is known. That is, in Patent Document 1, the strength of the end portion in the width direction of the fixing belt is improved by sticking a reinforcing resin tape (reinforcement portion) to both end portions in the width direction on the outer peripheral surface of the fixing belt. Yes. This prevents problems such as buckling and breakage from occurring at the end in the width direction of the fixing belt.

JP 2000-337464 A

  However, in Patent Document 1, since the strength of the end portion in the width direction of the fixing belt is improved by the resin tape, there is a problem that the resin tape is peeled off when the fixing device is used for a long time.

  Therefore, the present invention has been made in view of the above problems, and provides an endless belt with improved strength at the end in the width direction without causing a problem such as peeling of the reinforcing portion, and It is an object to provide a belt device and a fixing device using the endless belt, and an image forming apparatus using the fixing device.

  In order to solve the above-described problems, an endless belt of the present invention is an endless belt that is circulated and stretched around a plurality of rollers, and is formed across an endless base layer and an outer peripheral surface of the base layer in the circumferential direction. An elastic layer formed on the outer peripheral surface of the base layer and on both end portions of the outer peripheral surface of the base layer. And an elastic layer end portion having a hardness higher than the hardness of the elastic layer main body.

  According to said structure, since the hardness of an elastic layer edge part is made higher than the hardness of an elastic layer main body, the intensity | strength of the edge part of the width direction of an endless belt can be improved. That is, since the elastic layer end portion has a hardness higher than the hardness of the elastic layer body, it functions as a reinforcing portion that improves the strength of the end portion in the width direction of the endless belt.

  Moreover, since the elastic layer end portion is formed on the base layer, a sufficient joint surface between the elastic layer end portion and the base layer can be ensured, whereby the elastic layer end portion can be prevented from peeling off from the base layer. In particular, since the elastic layer end portion is formed on the base layer as an elastic layer, the elastic layer end portion is bonded to the base layer more firmly than in the case of bonding with a resin tape as in the prior art.

  An endless belt according to the present invention is the endless belt described above, wherein an end face of the elastic layer end portion in the width direction, an end face of the base layer in the width direction, and an inner peripheral face of the base layer. Further comprising a reinforcing portion formed over the end in the width direction.

  According to the above configuration, the reinforcing portion is formed across the outer end surface in the width direction at the end portion of the elastic layer, the end surface in the width direction in the base layer, and the end portion in the width direction on the inner peripheral surface of the base layer. The strength of the end portion in the width direction of the endless belt can be further improved.

  Further, since the reinforcing portion covers the boundary between the elastic layer end portion and the base layer, peeling between the elastic layer end portion and the base layer can be prevented.

  In addition, since the reinforcing part is formed up to the end in the width direction on the inner peripheral surface of the base layer, a sufficient joint surface between the reinforcing part and the base layer can be secured, thereby preventing the reinforcing part from peeling off from the base layer. it can.

  The endless belt of the present invention is the endless belt described above, and the hardness of the reinforcing portion is higher than the hardness of the elastic layer body.

  According to said structure, since the hardness of a reinforcement part has hardness higher than the hardness of an elastic layer main body, the intensity | strength of the edge part of the width direction of an endless belt can be improved effectively.

  The endless belt of the present invention is the endless belt described above, wherein the end portion of the inner peripheral surface of the base layer is inclined toward the outer peripheral surface side of the base layer, and the inner end of the base layer is A portion other than the end portion on the peripheral surface and a portion formed on the end portion of the base layer in the reinforcing portion are formed flush with each other.

  According to the above configuration, on the inner peripheral surface of the base layer other than the end portion in the width direction (hereinafter referred to as the end portion of the inner peripheral surface of the base layer) and the end portion of the inner peripheral surface of the base layer in the reinforcing portion Since the formed portion is formed flush with the formed portion, the portion formed on the end portion of the inner peripheral surface of the base layer in the reinforcing portion can be prevented from interfering with the roller.

  Moreover, since the edge part of the inner peripheral surface of a base layer inclines to the outer peripheral surface side of a base layer, it exists on parts other than the edge part in the inner peripheral surface of a base layer, and the edge part of the inner peripheral surface of the base layer in a reinforcement part. Even if the formed portion is formed flush with the formed portion, the thickness of the portion formed on the end portion of the inner peripheral surface of the base layer in the reinforcing portion can be sufficiently ensured.

  The endless belt of the present invention is the endless belt described above, and is a release layer formed over the elastic layer so as to cover the elastic layer main body and the elastic layer end. Is further provided.

  According to said structure, a mold release layer is formed over the circumferential direction of an elastic layer so that an elastic layer main body and an elastic layer edge part may be coat | covered. That is, since the elastic layer end portion is sandwiched between the release layer and the base layer, the elastic layer end portion can be further prevented from peeling from the base layer.

  In addition, since the release layer is provided, the toner image can be easily peeled even if the toner image adheres to the outer peripheral surface of the endless belt.

  The endless belt of the present invention is the endless belt described above, and is formed over the elastic layer so as to expose the end portion of the elastic layer and cover the elastic layer body. A release layer is further provided.

  According to said structure, since a peeling layer is provided, even if a toner image adheres to the outer peripheral surface of an endless belt, a toner image can be peeled easily.

  The endless belt of the present invention is the endless belt described above, wherein the elastic layer body and the elastic layer end are formed flush with each other.

  According to said structure, since an elastic layer main body and an elastic layer edge part are formed flush | planar, the outer peripheral surface of an endless belt can be made flat. Thus, when this endless belt is used as, for example, a fixing belt for fixing a toner image transferred onto a sheet to the sheet, a mark of a step between the elastic layer body and the elastic layer end is formed on the sheet. It can be prevented from remaining.

  The endless belt of the present invention is the endless belt described above, and the hardness of the end portion of the elastic layer is not more than the hardness of the base layer.

  According to said structure, since the hardness of an elastic layer edge part is below the hardness of a base layer, it can prevent impairing the flexibility of an endless belt by an elastic layer edge part.

  The endless belt of the present invention is the endless belt described above, and the hardness of the reinforcing portion is equal to or less than the hardness of the base layer.

  According to said structure, since the hardness of a reinforcement part is below the hardness of a base layer, it can prevent impairing the flexibility of an endless belt by a reinforcement part.

  The belt device of the present invention is a belt device using the endless belt described above, wherein the plurality of rollers are rotatably supported, and the endless belt is circulated and stretched around the plurality of rollers. Are provided.

  The endless belt of the present invention is supposed to be applied to fixing devices, but we have also created a claim for belt devices so that it can be applied to belt devices other than fixing devices.

  According to said structure, the belt apparatus with the effect of said endless belt can be provided.

  The belt device of the present invention is a belt device using the endless belt described above, wherein the plurality of rollers are rotatably supported, and the endless belt is circulated and stretched around the plurality of rollers. And a stepped portion that fits a portion formed on the end portion of the inner peripheral surface of the base layer in the reinforcing portion is formed at both end portions in the width direction on the outer peripheral surface of each roller. is there.

  According to said structure, the belt apparatus with the effect of said endless belt can be provided. In particular, a stepped portion that fits a portion formed on the end of the inner peripheral surface of the base layer in the reinforcing portion is formed at both ends in the width direction of the outer peripheral surface of each roller, so that the inner peripheral surface of the base layer in the reinforcing portion It can prevent that the part formed on the edge part of this interferes with a roller.

  Further, the belt device according to the present invention is the belt device described above, wherein at least one of the plurality of rollers has a peripheral wall portion provided circumferentially at both ends in the width direction on the outer peripheral surface thereof. It is.

  According to the above configuration, at least one of the plurality of rollers has peripheral wall portions provided at both ends in the width direction on the outer peripheral surface thereof, so that the endless belt is biased in the width direction (meandering or skewing). ) Can be prevented.

  In this case, the strength of the end portion in the width direction of the endless belt is improved by making the hardness of the elastic layer end portion higher than the hardness of the elastic layer body. Therefore, even if the end portion in the width direction of the endless belt comes into contact with the peripheral wall portion, it is possible to prevent problems such as buckling or failure from occurring in the end portion in the width direction of the endless belt.

  According to another aspect of the present invention, there is provided a fixing device for fixing a toner image transferred onto a sheet to the sheet, wherein the fixing device is the belt device described above and a predetermined one of the rollers. A roller, a pressure roller rotatably supported so as to press the fixing roller via the endless belt, and a heating unit for heating the endless belt. In the pressure contact area with the pressure roller, the toner image is fixed to the sheet by pressing and heating the sheet on which the toner image is transferred.

  According to said structure, the fixing device with the effect of said belt apparatus can be provided.

  The image forming apparatus of the present invention is an image forming apparatus that forms an image on a sheet, the transfer unit transferring a toner image reproducing the image onto the sheet, and the toner image transferred onto the sheet. The fixing device according to claim 11, wherein the fixing device is fixed to the paper.

  According to said structure, the image forming apparatus which has the effect of said fixing device can be provided.

  The endless belt, the belt device, the fixing device, and the image forming apparatus of the present invention include an endless base layer and an elastic layer formed in the circumferential direction on the outer peripheral surface of the base layer, and the elastic layer includes the An elastic layer body formed on the outer peripheral surface of the base layer other than both ends in the width direction; and formed on the both end portions of the outer peripheral surface of the base layer, and having a hardness higher than the hardness of the elastic layer main body. And an elastic layer end portion having.

  Therefore, the hardness of the end portion of the elastic layer is made higher than the hardness of the elastic layer main body, so that the strength of the end portion in the width direction of the endless belt can be improved. Moreover, since the elastic layer end portion is formed on the base layer, a sufficient joint surface between the elastic layer end portion and the base layer can be ensured, whereby the elastic layer end portion can be prevented from peeling off from the base layer. In particular, since the elastic layer end portion is formed on the base layer as an elastic layer, the elastic layer end portion is bonded to the base layer more firmly than in the case of bonding with a resin tape as in the prior art.

1 is a schematic cross-sectional view illustrating an example of an image forming apparatus according to a first embodiment. FIG. 2 is a schematic plan view of the fixing device shown in FIG. 1 and a schematic plan view of a conventional fixing device. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is IV-IV partial sectional drawing of FIG. FIG. 5 is a schematic cross-sectional view of the fixing belt of the first embodiment (a VV partial cross-sectional view of FIG. 3). FIG. 6 is a schematic cross-sectional view (a VI-VI partial cross-sectional view of FIG. 3) of a fixing belt according to a second embodiment. FIG. 7 is a schematic cross-sectional view of a fixing belt according to a third embodiment (partial sectional view taken along line VII-VII in FIG. 3). FIG. 8 is a partial cross-sectional schematic diagram (VIII-VIII partial cross-sectional view of FIG. 2) of a fixing roller of a fourth embodiment. It is the fragmentary sectional schematic of the heating roller of 4th Embodiment (IX-IX partial sectional drawing of FIG. 2). FIG. 10 is a schematic cross-sectional view (partial cross-sectional view taken along line XX in FIG. 3) of a fixing belt according to a fifth embodiment. FIG. 10 is a schematic cross-sectional view (XI-XI partial cross-sectional view of FIG. 3) of a fixing belt of a sixth embodiment. FIG. 4 is a schematic cross-sectional view of a conventional fixing belt (XII-XII partial cross-sectional view of FIG. 3).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<< First Embodiment >>
<Overall configuration>
FIG. 1 is a schematic sectional view showing an example of an image forming apparatus according to the first embodiment of the present invention. The image forming apparatus 1 prints and records an image indicated by image data on a recording sheet. As shown in FIG. 1, the image forming apparatus 1 includes a paper feed cassette 3 that supplies recording paper (paper), a toner image forming apparatus 4 that forms a toner image that reproduces the image, and a toner image forming apparatus 4. A secondary transfer device (hereinafter referred to as a transfer device) 5 for transferring the toner image formed by the transfer device 5 to the recording paper supplied from the paper feed cassette 3, and fixing the toner image transferred by the transfer device 5 to the recording paper. The fixing device 6 to be discharged, the paper discharge tray 7 from which the recording paper carried out of the fixing device 6 is discharged, and the recording paper supplied from the paper feed cassette 3 to the transfer device 5, the fixing device 6 and the paper discharge tray 7 in order And a transport path S for transporting. The paper discharge tray 7 is formed on, for example, the upper surface of the image forming apparatus 1.

  Although details will be described later in this image forming apparatus 1, as shown in FIG. 2, in the heating roller 43 of the fixing device 6, a bias (meandering or skewing) of the fixing belt 44 (endless belt) is prevented. Further, as shown in FIG. 5, the peripheral belt portion 43 c is provided. Further, as shown in FIG. 5, the fixing belt 44 prevents the end portion 44 e of the fixing belt 44 from causing problems such as buckling and failure due to the offset force from the peripheral wall portion 43 c. The strength of the end portion 44e is improved.

<Toner image forming apparatus 4>
For example, the toner image forming apparatus 4 reproduces the image by superimposing toner images of four basic colors of black (K), cyan (C), magenta (M), and yellow (Y). . As shown in FIG. 1, the toner image forming apparatus 4 includes four image stations Pa, Pb, Pc, and Pd corresponding to each color of KCMY, an optical scanning device 11, and an intermediate transfer belt device 16.

  Each image station Pa, Pb, Pc, Pd forms a toner image of each color of KCMY. Each of the image stations Pa, Pb, Pc, and Pd includes developing devices 12a, 12b, 12c, and 12d, photosensitive drums 13a, 13b, 13c, and 13d, drum cleaning devices 14a, 14b, 14c, and 14d, and a charger. 15a, 15b, 15c, 15d.

  Each of the photosensitive drums 13a, 13b, 13c, and 13d has a photosensitive layer on the surface thereof. Each of the chargers 15a, 15b, 15c, and 15d uniformly charges the surface of each of the photosensitive drums 13a, 13b, 13c, and 13d to a predetermined potential.

  Based on the image data, the optical scanning device 11 irradiates the surfaces of the charged photosensitive drums 13a, 13b, 13c, and 13d with light, and gives electrostatic latent images corresponding to the image data to those surfaces. Form. Each of the developing devices 12a, 12b, 12c, and 12d develops the electrostatic latent image formed on the surface of each of the photosensitive drums 13a, 13b, 13c, and 13d with each color toner, and each of the photosensitive drums 13a, 13b. , 13c, and 13d, toner images of respective colors are formed.

  Each drum cleaning device 14a, 14b, 14c, 14d removes and collects the toner remaining on the surface of each photosensitive drum 13a, 13b, 13c, 13d.

  The intermediate transfer belt device 16 superimposes the toner images of the respective colors formed by the image stations Pa, Pb, Pc, and Pd to form a toner image that reproduces the image. The intermediate transfer belt device 16 includes an intermediate transfer belt 21, an intermediate transfer belt drive roller 22, a driven roller 23, intermediate transfer rollers 24a, 24b, 24c, and 24d, and a belt cleaning device 25.

  The intermediate transfer belt 21 has an endless belt shape. The intermediate transfer belt 21 is stretched and supported by an intermediate transfer belt drive roller 22, a driven roller 23, and intermediate transfer rollers 24a, 24b, 24c, and 24d. For example, the intermediate transfer belt drive roller 22 is rotationally driven. Circulates in the direction of arrow C, for example.

  Each of the intermediate transfer rollers 24 a, 24 b, 24 c, and 24 d transfers the toner images formed on the surfaces of the photosensitive drums 13 a, 13 b, 13 c, and 13 d to the intermediate transfer belt 21. The intermediate transfer rollers 24a, 24b, 24c, and 24d are rotatably supported by the photosensitive drums 13a, 13b, 13c, and 13d via the intermediate transfer belt 21, respectively.

  In the intermediate transfer belt device 16, for example, the intermediate transfer belt 21 is circulated and moved by the driving rotation of the intermediate transfer belt drive roller 22, and the photosensitive drums 13 a, 13 b, 13 c, and 13 d are driven to rotate along with the circulation movement. With this driven rotation, the toner images on the surfaces of the photosensitive drums 13a, 13b, 13c, and 13d are sequentially pressed onto the intermediate transfer belt 21 and transferred. The image is reproduced by the superimposed toner images.

  Here, a transfer bias for transferring the toner image by electrostatic attraction is applied to the surface of each of the intermediate transfer rollers 24a, 24b, 24c, and 24d. Thus, when the toner images on the surfaces of the photosensitive drums 13a, 13b, 13c, and 13d are pressed against the intermediate transfer belt 21, the surface of the photosensitive drums 13a, 13b, 13c, and 13d is electrostatically attracted. The toner image is transferred to the intermediate transfer belt 21.

  Thus, a toner image that reproduces the image is formed on the intermediate transfer belt 21. The toner image thus formed on the intermediate transfer belt 21 is conveyed to the transfer device 5 by the circulation movement of the intermediate transfer belt 21, and is transferred onto the recording paper by the transfer device 5.

  The belt cleaning device 25 removes and collects residual toner on the surface of the intermediate transfer belt 21.

<Transfer device 5>
The transfer device 5 transfers a toner image formed on the surface of the intermediate transfer belt 21 onto a recording sheet, and includes a secondary transfer roller 5a as shown in FIG. The secondary transfer roller 5 a is rotatably supported so as to be pressed against the intermediate transfer belt driving roller 22 via the intermediate transfer belt 21.

  In the transfer device 5, the secondary transfer roller 5 a is driven to rotate as the intermediate transfer belt 21 circulates. In this state, the toner image on the surface of the intermediate transfer belt 21 is supplied to the pressure contact area (nip area) between the intermediate transfer belt 21 and the secondary transfer roller 5a in accordance with the timing when the toner image is pressed against the secondary transfer roller 5a. When the recording paper supplied from the paper cassette 3 is carried in, the toner image formed on the surface of the intermediate transfer belt 21 is transferred to the recording paper.

  Here, a transfer bias for transferring the toner image by electrostatic attraction is applied to the surface of the secondary transfer roller 5a. Thereby, in the nip area between the intermediate transfer belt 21 and the secondary transfer roller 5a, when the toner image on the surface of the intermediate transfer belt 21 is pressed against the recording paper, the electrostatic transfer force causes the intermediate transfer belt 21 to move. The toner image on the surface is transferred to the recording paper.

<Fixing device 6>
(Configuration of Fixing Device 6)
2 is a schematic plan view of the fixing device 6, FIG. 3 is a sectional view taken along the line III-III in FIG. 2, FIG. 4 is a partial sectional view taken along the line IV-IV in FIG. FIG. 5 is a VV partial cross-sectional view of FIG. 3.

  The fixing device 6 is of a belt fixing type, and includes a pressure roller 41, a fixing roller 42, a heating roller 43, and a fixing belt 44 as shown in FIGS. 2 and 4 indicates the width direction of each of the rollers 41, 42, 43 and the fixing belt 44.

  Here, a belt device is constituted by the rollers 41, 42, 42 and the fixing belt 44.

  Each roller 41, 42, 43 is supported rotatably. Further, the fixing roller 42 and the heating roller 43 are spaced apart from each other. The fixing belt 44 is stretched and supported by a fixing roller 42 and a heating roller 43. The pressure roller 41 is disposed so as to be pressed against the fixing roller 42 via the fixing belt 44.

  For example, one predetermined roller (for example, pressure roller 41) in each of the rollers 41, 42, and 43 is a driving roller that is rotationally driven by a predetermined motor (not shown), and other rollers (for example, fixing rollers). 42 and the heating roller 43) are driven rollers that are driven to rotate as the driving roller rotates.

  As shown in FIG. 3, the pressure roller 41 is, for example, a roller having a multi-layer structure (here, three layers). For example, a hollow rotating shaft portion 41a and an elastic surface formed on the outer peripheral surface of the rotating shaft portion 41a. A layer 41b and a release layer 41c formed on the outer peripheral surface of the elastic layer 41b are provided. The elastic layer 41b is formed thinner than the release layer 41c, for example.

  The fixing roller 42 is, for example, a roller having a multi-layer structure (here, two layers) and includes, for example, a hollow rotating shaft portion 42a and an elastic layer 42b formed on the outer peripheral surface of the rotating shaft portion 42a. The elastic layer 42b is formed to be sufficiently thick (for example, thicker than the rotating shaft portion 42a), for example.

  The heating roller 43 is, for example, a roller having a multi-layer structure (here, two layers), and includes, for example, a hollow rotating shaft portion 43a and a surface layer 43b formed on the outer peripheral surface of the rotating shaft portion 43a. In addition, a heater lamp 46 (for example, a halogen lamp) is disposed as a heat source (heating means) for heating the fixing belt 44 via the heating roller 43 inside the rotating shaft 43a.

  Further, at both end portions 43d2 in the width direction H of the outer peripheral surfaces (43d1 and 43d2) of the heating roller 43, a peripheral wall portion 43c is provided so as to project to the outer peripheral side of the heating roller 43 as shown in FIG. The The peripheral wall 43c prevents the fixing belt 44 from being biased (meandering or skewing) in the width direction H.

  More specifically, in this heating roller 43, as shown in FIG. 4, the surface layer 43b has a circumferential surface such that the end 43d2 in the width direction H is exposed on the outer circumferential surface (43d2 and 43d3) of the rotating shaft 43a. It is formed over the direction. The peripheral wall portion 43c is circumferentially provided at the end portion 43d2 of the outer peripheral surface (43d2 and 43d3) of the rotating shaft portion 43a so as to be adjacent to the surface layer 43b and to protrude outward from the outer peripheral surface 43d1 of the surface layer 43b. The

  The fixing belt 44 is an endless belt made of a material having good heat conduction. As shown in FIG. 5, the fixing belt 44 is formed in an endless base layer 44a, an elastic layer 44b formed on the outer peripheral surface 44a1 of the base layer 44a in the circumferential direction, and on the elastic layer 44b in the circumferential direction. A release layer 44c.

  The base layer 44a is formed to a thickness of, for example, 30 μm to 100 μm by using a material such as PI (polyimide), Ni (nickel), or SUS (stainless steel).

  The elastic layer 44b is formed on the elastic layer body 44b1 formed on the portion 44a3 other than both end portions 44a2 in the width direction H of the outer peripheral surface 44a1 of the base layer 44a, and on both end portions 44a2 of the outer peripheral surface 44a1 of the base layer 44a. And an elastic layer end 44b2 having a hardness higher than that of the layer body 44b1.

  The elastic layer main body 44b1 is formed with a thickness of, for example, 100 μm to 400 μm using a resin material such as Si (silicon) rubber (for example, hardness 45 °).

  The elastic layer end portion 44b2 has a hardness higher than that of the elastic layer main body 44b1, and more preferably is formed of a material having a hardness equal to or lower than the hardness of the base layer 44a. Here, the elastic layer end portion 44b2 is formed to a thickness of, for example, 100 μm to 400 μm using a material such as Si rubber (for example, hardness 80 ° to 90 °) or an epoxy resin.

  Here, the hardness is measured by a measuring method such as an Asker C rubber hardness meter.

  Since the hardness of the elastic layer end portion 44b2 is higher than the hardness of the elastic layer main body 44b1, the strength of the end portion 44e in the width direction H of the fixing belt 44 can be improved. In other words, the elastic layer end portion 44b2 functions as a reinforcing portion that improves the strength of the end portion 44e in the width direction H of the fixing belt 44 by having a hardness higher than the hardness of the elastic layer body 44b1. Further, since the hardness of the elastic layer end portion 44b2 is equal to or less than the hardness of the base layer 44a, it is possible to prevent the elastic layer end portion 44b from impairing the flexibility of the fixing belt 44.

  Each of the elastic layer main body 44b1 and the elastic layer end 44b2 is formed on the base layer 44a, for example, by coating or molding. Thereby, the elastic layer main body 44b1 and the elastic layer end portion 44b2 (particularly, the elastic layer end portion 44b2) are formed by being firmly bonded onto the base layer 44a.

  The elastic layer body 44b1 and the elastic layer end 44b2 may be formed by primer bonding. That is, in this case, a primer (that is, a primer that improves adhesion to the base layer 44a) is applied onto the portion 44a3 other than the end 44a2 on the outer peripheral surface 44a1 of the base layer 44a, and the elastic layer body 44b1 is applied. Formed by molding. Then, the adhesion between the primer (that is, the elastic layer main body 44b1 and the base layer 44a) is improved on the end surface 44f in the width direction H of the elastic layer main body 44b1 and the end portion 44a2 in the width direction H of the outer peripheral surface 44a1 of the base layer 44a. Apply primer. Then, the elastic layer end portion 44b2 is formed on the end portion 44a2 of the outer peripheral surface 44a1 of the base layer 44a by coating or molding so as to be joined to the end surface 44f of the elastic layer body 44b1.

  The outer peripheral surface 44b3 of the elastic layer main body 44b1 and the outer peripheral surface 44b4 of the elastic layer end 44b2 are formed flush with each other. The elastic layer body 44b1 and the elastic layer end 44b2 are preferably formed integrally with each other.

  The release layer 44c allows the toner image attached to the outer peripheral surface of the fixing belt 44 (that is, the outer peripheral surface of the release layer 44c) 44g to be easily peeled off. The release layer 44c is formed on the elastic layer 44b in the circumferential direction so as to cover the elastic layer main body 44b1 and the elastic layer end 44b2. Here, the release layer 44c is formed to a thickness of, for example, 5 μm to 40 μm by, for example, a PFA (fluororesin) coat or a PFA tube.

(Operation of the fixing device 6)
In the fixing device 6, as described above, the elastic layer 42b of the fixing roller 42 is formed to be sufficiently thick. As a result, as shown in FIG. 3, when the pressure roller 41 is pressed against the fixing roller 42 via the fixing belt 44, the elastic layer 42b of the fixing roller 42 is greatly recessed, and the pressure roller 41 and the fixing roller 42 A pressure contact region (nip region) N is formed between the two.

  In this state, for example, when the pressure roller 41 is rotationally driven in the arrow direction D, the fixing roller 42 is driven to rotate in the arrow direction F and the fixing belt 44 is circulated and moved in the arrow direction E along with the rotational driving. With this circulation movement, the heating roller 43 is driven to rotate in the direction indicated by the arrow G.

  At this time, the fixing belt 44 circulates and moves through the nip region N while being heated by the heating roller 43, and the nip region N is heated by the fixing belt 44. When the recording paper passes through the nip region N, the recording paper is pressurized and heated by the fixing belt 44 and the pressure roller 41, and the toner image on the recording paper is fixed to the recording paper.

  In the meantime (that is, during the circulating movement of the fixing belt 44), the fixing belt 44 has its end surface 44d (see FIG. 2) in the width direction H abutting on the peripheral wall 43c of the heating roller 43 as shown in FIG. Therefore, it is possible to prevent deviation in the width direction H. At this time, since the strength of the end portion 44e of the fixing belt 44 is improved as described above, even if the end surface 44d of the fixing belt 44 contacts the peripheral wall portion 43c, the end portion 44e of the fixing belt 44 buckles. It is possible to prevent problems such as failure and failure.

  In this way, the recording paper on which the toner image is fixed by the fixing device 6 is carried out of the fixing device 6 and discharged to the paper discharge tray 7.

<Paper cassette 3>
As shown in FIG. 1, the paper feed cassette 3 is disposed, for example, at a lower portion of the image forming apparatus 1. The paper feed cassette 3 includes a paper feed cassette main body 3a on which recording paper is placed, a pickup roller 3b that pulls out the recording paper one by one from the paper feed cassette main body 3a, and a recording paper drawn by the pickup roller 3b. And an unloading roller 3c for unloading to S. The pickup roller 3a is disposed at, for example, an end portion of the paper feed cassette body 3a.

<Conveyance path S>
As shown in FIG. 1, the transport path S is formed so that the recording paper from the paper feed cassette 3 is sequentially transported to the transfer device 5, the fixing device 6, and the paper discharge port 35. That is, the transport path S is formed so as to connect the paper feed cassette 3 and the paper discharge port 35 via the transfer device 5 and the fixing device 6.

  In the conveyance path S, a registration roller 32, a conveyance roller 33, a paper discharge roller 34, and the like are arranged.

  The conveyance rollers 33 are small rollers for promoting and assisting the conveyance of the recording paper, and a plurality of sets are arranged along the conveyance path S.

  One set of registration rollers 32 is arranged in the vicinity of the paper carry-in side of the transfer device 5. The registration roller 32 temporarily stops the recording paper that has been conveyed, and the recording paper is rotated in accordance with the rotation of the intermediate transfer belt 21 so that the toner image on the intermediate transfer belt 21 is transferred to the recording paper. It is carried into the transfer device 5.

  The carry-out roller 34 is arranged, for example, on the front side of the paper discharge port 35, and discharges the recording paper carried out from the fixing device 6 from the carry paper port 35 to the paper discharge tray 7.

<Operation of Image Forming Apparatus 1>
The recording paper in the paper feed cassette 3 is taken out by the pickup roller 3b, conveyed along the conveyance path S by the rollers 3c, 33, 32, and conveyed to the transfer device 5. In the transfer device 5, the recording paper is passed through the pressure contact area between the intermediate transfer belt 21 and the secondary transfer roller 26 a, so that the toner image formed on the recording paper by the toner image forming device 4. Is transcribed.

  Then, the recording sheet is carried out to the fixing device 6. In the fixing device 6, the recording paper is passed through the pressure contact area between the fixing belt 44 and the pressure roller 41, so that the toner image transferred to the recording paper is fixed. At that time, the fixing belt 44 is circulated and moved well without being biased in the width direction H by the peripheral wall portion 43 c of the heating roller 43. Further, since the strength of the end portion 44e of the fixing belt 44 is improved as described above, it is possible to prevent the end portion 44e of the fixing belt 44 from being troubled such as buckling or failure. 44 circulates well.

  Then, the recording sheet on which the toner image is fixed by the fixing device 6 is unloaded from the fixing device 6 and is unloaded from the discharge port 35 to the discharge tray 7 by the discharge roller 34.

<Main Effects of Image Forming Apparatus 1>
As described above, according to the image forming apparatus 1, since the hardness of the elastic layer end portion 44b2 is higher than the hardness of the elastic layer body 44b1, the strength of the end portion 44e in the width direction H of the fixing belt 44 can be improved. .

  Further, since the elastic layer end portion 44b2 is formed on the base layer 44a, a sufficient bonding surface between the elastic layer end portion 44b2 and the base layer 44a can be ensured, whereby the elastic layer end portion 44b2 is peeled off from the base layer 44a. Can be prevented. In particular, since the elastic layer end 44b2 is formed on the base layer 44a as an elastic layer, the elastic layer end portion 44b2 is more firmly bonded to the base layer 44a than in the case of bonding with a resin tape as in the prior art.

  The release layer 44c is formed over the circumferential direction of the elastic layer 44b so as to cover the elastic layer main body 44b1 and the elastic layer end 44b2. That is, since the elastic layer end portion 44b2 is sandwiched between the release layer 44c and the base layer 44a, the elastic layer end portion 44b2 can be prevented from peeling off from the base layer 44a.

  Further, since the outer peripheral surface 44b3 of the elastic layer main body 44b1 and the outer peripheral surface 44b4 of the elastic layer end 44b2 are formed flush with each other, the outer peripheral surface 44g of the fixing belt 44 can be made flat. As a result, when the recording paper is passed through the pressure contact area between the fixing belt 44 and the pressure roller 41, a mark of a step between the elastic layer body 44b1 and the elastic layer end 44b2 is formed on the recording paper. It can be prevented from remaining.

<< Second Embodiment >>
In this embodiment, a modification of the fixing belt 44 of the first embodiment will be described. FIG. 6 is a schematic cross-sectional view of the fixing belt according to the second embodiment (that is, a partial cross-sectional view taken along line VI-VI in FIG. 3).

  As shown in FIG. 6, the fixing belt 44B of this embodiment is obtained by omitting the release layer 44c from the fixing belt 44 (see FIG. 5) of the first embodiment.

  According to this embodiment, in the fixing belt 44B, compared to the fixing belt 44 of the first embodiment, the elastic layer end portion 44b2 is easily peeled off from the base layer 44a because the release layer 44c is not provided. However, since the elastic layer end 44b2 is formed on the base layer 44a, a sufficient joint surface between the elastic layer end 44b2 and the base layer 44a can be secured, whereby the elastic layer end 44b2 is peeled off from the base layer 44a. Can be sufficiently prevented. In particular, since the elastic layer end 44b2 is formed on the base layer 44a as an elastic layer, the elastic layer end portion 44b2 is more firmly bonded to the base layer 44a than in the case of bonding with a resin tape as in the prior art.

«Third embodiment»
In this embodiment, a modification of the fixing belt 44 of the first embodiment will be described. FIG. 7 is a schematic sectional view of the fixing belt according to the third embodiment (that is, a partial sectional view taken along line VII-VII in FIG. 3).

  As shown in FIG. 7, the fixing belt 44 </ b> C of this embodiment includes a reinforcing portion for improving the strength of the end in the width direction H of the fixing belt 44 in the fixing belt 44 (see FIG. 5) of the first embodiment. 44h.

  The reinforcing portion 44h includes an end surface 44c1 in the width direction H in the release layer 44c, an end surface 44b5 in the width direction H in the elastic layer end portion 44b2, an end surface 44a4 in the width direction H in the base layer 44a, and an inner peripheral surface of the base layer 44a. It is formed across the end 44a6 in the width direction H at 44a5.

  Here, the reinforcing portion 44h is also formed on the end surface 44c1 of the release layer 44c, but may not be formed on the end surface 44c1 of the release layer 44c.

  Similarly to the elastic layer end portion 44b2, the reinforcing portion 44h has a hardness higher than that of the elastic layer body 44b1, and more preferably is formed of a material having a hardness equal to or lower than the hardness of the base layer 44a. Here, similarly to the elastic layer end portion 44b2, the reinforcing portion 44h is formed of a material such as Si rubber (for example, hardness 80 ° to 90 °) or an epoxy resin.

  The reinforcing portion 44h is formed by, for example, coating, molding, or primer bonding, similarly to the elastic layer end portion 44b2. Further, the reinforcing portion 44h and the elastic layer end portion 44b2 may be integrally formed.

  According to this embodiment, in the fixing belt 44C, the reinforcing portion 44h includes the outer end surface 44b5 in the width direction H of the elastic layer end portion 44b2, the end surface 44a4 in the width direction H of the base layer 44a, and the inner peripheral surface of the base layer 44a. Since it is formed over the end portion 44a6 in the width direction H at 44a5, the strength of the end portion 44e in the width direction H of the fixing belt 44C can be further improved. At this time, since the hardness of the reinforcing portion 44h is higher than the hardness of the elastic layer main body 44b1, the strength of the end portion 44e in the width direction H of the fixing belt 44C can be effectively improved.

  Further, since the reinforcing portion 44h covers the boundary between the elastic layer end portion 44b2 and the base layer 44a, peeling between the elastic layer end portion 44b2 and the base layer 44a can be prevented.

  Further, since the reinforcing portion 44h is formed up to the end portion 44a6 in the width direction H on the inner peripheral surface 44a5 of the base layer 44a, a sufficient joint surface between the reinforcing portion 44h and the base layer 44a can be ensured, and thereby the reinforcing portion 44h. Can be prevented from peeling from the base layer 44a.

  In the above description, the hardness of the reinforcing portion 44h is described as being higher than the hardness of the elastic layer body 44b1, but may be lower than the hardness of the elastic layer body 44b1. Even if the hardness is lower than the hardness of the elastic layer main body 44b1, the strength of the end portion 44e of the fixing belt 44C can be improved by adding the reinforcing portion 44h.

<< Fourth Embodiment >>
This embodiment is a modification of the third embodiment. 8 is a schematic cross-sectional view of the fixing roller of the fourth embodiment (ie, a partial cross-sectional view of VIII-VIII in FIG. 2), and FIG. 9 is a schematic cross-sectional view of the pressure roller of the fourth embodiment (ie, FIG. 2). IX-IX partial sectional view).

  In this embodiment, as shown in FIG. 8, at the end portion in the width direction H of the outer peripheral surface 42c of the fixing roller 42D of the fixing device 6, the end portion of the inner peripheral surface 44a5 of the base layer 44a in the reinforcing portion 44h of the fixing belt 44C. A stepped portion 42d is formed into which the portion 44h1 formed on 44a6 fits. In other words, the stepped portion 42d is formed in a portion of the outer peripheral surface 42c of the fixing roller 42D that faces the portion 44h1 of the fixing belt 44C.

  In this embodiment, as shown in FIG. 9, the inner peripheral surface 44a5 of the base layer 44a in the reinforcing portion 44h of the fixing belt 44C is provided at the end in the width direction H of the outer peripheral surface 43e of the pressure roller 43D of the fixing device 6. A stepped portion 43f into which a portion 44h1 formed on the end portion 44a6 is fitted is formed. In other words, the stepped portion 43f is formed in a portion of the outer peripheral surface 43e of the heating roller 43D that faces the portion 44h1 of the fixing belt 44C.

  The step portions 42d and 43f are preferably formed deeper than the thickness of the portion 44h1 of the reinforcing portion 44h.

  According to this embodiment, the portions 44h1 formed on the end portions 44a6 of the inner peripheral surface 44a5 of the base layer 44a in the reinforcing portion 44h are formed at both ends in the width direction H of the outer peripheral surfaces 42c and 43e of the rollers 42D and 43D. Since the step portions 42d and 43f to be fitted are formed, the portion 44h1 formed on the end portion 44a6 of the inner peripheral surface 44a5 of the base layer 44a in the reinforcing portion 44h can be prevented from interfering with the rollers 42D and 43D.

«Fifth embodiment»
This embodiment is a modification of the third embodiment. FIG. 10 is a schematic cross-sectional view of the fixing belt of the fifth embodiment (that is, a partial cross-sectional view taken along the line XX in FIG. 3).

  In the fixing belt 44E of this embodiment, as shown in FIG. 10, the end 44a6 in the width direction H of the inner peripheral surface 44a5 of the base layer 44a is inclined toward the outer peripheral surface 44a1 side of the base layer 44a. More specifically, the end portion 44a6 of the inner peripheral surface 44a5 of the base layer 44a has a thickness that decreases from the portion 44a7 side of the base layer 44a toward the outer side in the width direction H, on the outer peripheral surface 44a1 side of the base layer 44a. It is inclined to.

  The reinforcing layer 44h of this embodiment includes an end surface 44c1 in the width direction H of the release layer 44c, an end surface 44b5 of the elastic layer end portion 44b2 on the outer side in the width direction H, and a width direction H of the inner peripheral surface 44a5 of the base layer 44a. It is formed over the end 44a6. In this state, the portion 44a7 other than the end portion 44a6 on the inner peripheral surface 44a5 of the base layer 44a and the portion 44h1 formed on the end portion 44a6 of the base layer 44a in the reinforcing portion 44h are formed flush with each other.

  Here, the end portion 44a6 of the inner peripheral surface 44a4 of the base layer 44a is inclined toward the outer peripheral surface 44a1, so that the end surface 44a4 (see FIG. 7) in the width direction H in the base layer 44a is completely eliminated, but the end surface 44a4 of the base layer 44a. The end 44a6 of the inner peripheral surface 44a4 of the base layer 44a may be inclined toward the outer peripheral surface 44a1 side of the base layer 44a (that is, the inclination of the end 44a6 may be made gentler). In that case, the reinforcing portion 44h is also formed over the end surface 44a4.

  According to this embodiment, in the fixing belt 44E, the portion 44a7 other than the end portion 44a6 in the width direction H on the inner peripheral surface 44a5 of the base layer 44a and the end portion 44a6 of the inner peripheral surface 44a5 of the base layer 44a in the reinforcing portion 44h. Since the formed portion 44h1 is flush with the formed portion 44h1, the portion 44h1 formed on the end portion 44a6 of the inner peripheral surface 44a5 of the base layer 44a in the reinforcing portion 44h is prevented from interfering with the rollers 42 and 43. it can.

  Further, since the end portion 44a6 of the inner peripheral surface 44a5 of the base layer 44a is inclined toward the outer peripheral surface 44a1 side of the base layer 44a, the portion 44a7 other than the end portion 44a6 on the inner peripheral surface 44a5 of the base layer 44a and the reinforcing portion 44h. Even if the portion 44h1 formed on the end portion 44a6 of the inner peripheral surface 44a5 of the base layer 44a is flush with the portion 44h1, the portion 44h1 formed on the end portion 44a6 of the inner peripheral surface 44a5 of the base layer 44a in the reinforcing portion 44h. A sufficient thickness can be secured.

<< Sixth Embodiment >>
In this embodiment, a modification of the third embodiment will be described. FIG. 11 is a schematic sectional view of the fixing belt according to the sixth embodiment (that is, a partial sectional view taken along line XI-XI in FIG. 3).

  In the fixing belt 44C of the third embodiment (see FIG. 7), the release layer 44c is formed along the circumferential direction of the elastic layer 44b so as to cover the elastic layer main body 44b1 and the elastic layer end 44b2. However, in the fixing belt 44F of this embodiment, the release layer 44c is arranged in the circumferential direction of the elastic layer 44b so as to expose the elastic layer end portion 44b2 and cover the elastic layer main body 44b1, as shown in FIG. Formed over. At this time, it is desirable that the outer peripheral surface 44c2 of the release layer 44c and the outer peripheral surface 44b6 of the elastic layer end portion 44b2 be formed flush with each other.

  According to this embodiment, compared with the fixing belt 44C of the third embodiment, the elastic layer end 44b2 is peeled off from the base layer 44a in the fixing belt 44F because the elastic layer end 44b2 is not covered with the release layer 44c. It becomes easy. However, since the elastic layer end 44b2 is formed on the base layer 44a, a sufficient joint surface between the elastic layer end 44b2 and the base layer 44a can be secured, whereby the elastic layer end 44b2 is peeled off from the base layer 44a. Can be sufficiently prevented. In particular, since the elastic layer end 44b2 is formed on the base layer 44a as an elastic layer, the elastic layer end portion 44b2 is more firmly bonded to the base layer 44a than in the case of bonding with a resin tape as in the prior art.

<Attachment>
As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to such an example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. It is understood.

  Further, it is understood that the invention combining any of the first to sixth embodiments belongs to the technical scope of the present invention.

  In the first to sixth embodiments, the fixing belts 44, 44B, 44C, 44D, 44E, and 44F have their elastic layer end portions made harder than the elastic layer body, thereby fixing each of them. The strength of the end portion in the width direction of the belt was improved (this technique is hereinafter referred to as the present invention). However, the present invention is not limited to the application to the fixing belt, and any endless belt having an endless base layer and an elastic layer formed in the circumferential direction on the outer peripheral surface of the base layer may be used. It can also be applied to endless belts. For example, the present invention may be applied to the intermediate transfer belt 21 of the first embodiment.

  In the first to sixth embodiments, the present invention has been described in the case of being used in combination with the roller 43 having the peripheral wall portion 43c. However, the peripheral wall is used for all rollers used in combination with the present invention. The part 43c may be omitted. Even if it is not combined with a roller having a peripheral wall portion, the endless belt to which the present invention is applied has an effect of improving the durability of the endless belt by improving the strength of the end portion in the width direction.

  In the first embodiment, the fixing belt 44 is stretched by two rollers, that is, a heating roller 43 and a fixing roller 42, and a peripheral wall portion 43 c is formed only on the heating roller 43. However, the number of rollers for stretching the fixing belt 44 may be three or more, and the number of rollers having the peripheral wall portion 43c may be two or more.

  This image forming apparatus is most suitable for application to an electrophotographic copying machine or printer.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 5 Transfer apparatus 6 Fixing apparatus 41 Pressure roller 42 Fixing rollers 42d and 43f Step part 43 Heating roller 43c Perimeter wall part 44a
44, 44B, 44D, 44E, 44F Fixing belt (endless belt)
44a Base layer 44a1 Base layer outer peripheral surface 44a2 Base layer outer peripheral surface end 44a3 Base layer outer peripheral surface other than end 44a4 Base layer end surface 44a5 Base layer inner peripheral surface 44a6 Base layer inner peripheral surface 44a7 Base layer inner peripheral 44b Elastic layer 44b1 Elastic layer body 44b2 Elastic layer end 44b5 End surface of elastic layer end 44c Release layer 44h Reinforcing part 44h1 Formed on the end part of the inner peripheral surface of the base layer in the reinforcing part Part 46 Heater lamp (heating means)
H width direction

Claims (14)

An endless belt that is stretched around a plurality of rollers and circulates,
An endless base layer,
An elastic layer formed in the circumferential direction on the outer peripheral surface of the base layer;
With
The elastic layer is
An elastic layer body formed on a portion other than both ends in the width direction on the outer peripheral surface of the base layer;
An elastic layer end formed on the both end portions of the outer peripheral surface of the base layer and having a hardness higher than the hardness of the elastic layer body;
An endless belt characterized by comprising: The endless belt according to claim 1,
It further includes a reinforcing portion formed across the end surface in the width direction on the elastic layer end portion, the end surface in the width direction in the base layer, and the end portion in the width direction on the inner peripheral surface of the base layer. Endless belt characterized by. The endless belt according to claim 2,
The endless belt characterized in that the hardness of the reinforcing portion is higher than the hardness of the elastic layer body. The endless belt according to claim 2,
The end portion of the inner peripheral surface of the base layer is inclined toward the outer peripheral surface side of the base layer,
The endless belt, wherein a portion other than the end portion on the inner peripheral surface of the base layer and a portion formed on the end portion of the base layer in the reinforcing portion are formed flush with each other. The endless belt according to any one of claims 1 to 4,
An endless belt, further comprising a release layer formed over a circumferential direction of the elastic layer so as to cover the elastic layer body and the elastic layer end. The endless belt according to any one of claims 1 to 4,
An endless belt, further comprising a release layer formed along the circumferential direction of the elastic layer so as to expose the end portion of the elastic layer and cover the elastic layer main body. The endless belt according to any one of claims 1 to 6,
The endless belt, wherein the elastic layer body and the elastic layer end are formed flush with each other. It is an endless belt given in any 1 paragraph of Claims 1-7,
The endless belt characterized in that the hardness of the end portion of the elastic layer is equal to or less than the hardness of the base layer. An endless belt according to claim 2,
The endless belt according to claim 1, wherein a hardness of the reinforcing portion is equal to or less than a hardness of the base layer. A belt device using the endless belt according to any one of claims 1 to 9,
A plurality of rollers rotatably supported;
The endless belt stretched around the plurality of rollers and circulated;
A belt device comprising: A belt device using the endless belt according to claim 2,
A plurality of rollers rotatably supported;
The endless belt stretched around the plurality of rollers and circulated;
With
The belt device is characterized in that a stepped portion is formed at both ends in the width direction of the outer peripheral surface of each of the rollers so that a portion formed on the end portion of the inner peripheral surface of the base layer in the reinforcing portion is fitted. . The belt device according to claim 10 or 11,
At least one of the plurality of rollers has a peripheral wall portion provided at both ends in the width direction on the outer peripheral surface thereof. A fixing device for fixing a toner image transferred on a sheet to the sheet,
The belt device according to any one of claims 10 and 11,
A fixing roller that is a predetermined one of the rollers;
A pressure roller rotatably supported so as to press the fixing roller via the endless belt;
Heating means for heating the endless belt;
With
A fixing device in which the toner image is fixed to the sheet by pressurizing and heating the sheet on which the toner image is transferred in a pressure contact region between the endless belt and the pressure roller. . An image forming apparatus for forming an image on paper,
A transfer device for transferring a toner image reproducing the image onto the paper;
The fixing device according to claim 11, wherein the toner image transferred to the paper is fixed on the paper.
An image forming apparatus comprising:

Images