JP5470952B2 - Fixing belt, fixing device, and image forming apparatus - Google Patents

Description

  The present invention relates to a fixing belt, a fixing device, and an image forming apparatus.

  Patent Document 1 includes a fixing belt, a fixing member that receives friction on the inner peripheral surface of the fixing belt, and a pressure rotating body that is pressed by the fixing member via the fixing belt and rotates together with the fixing belt. A fixing device is described.

  Then, the contact portion N between the fixing belt and the pressure rotator and the recording medium on which the unfixed toner image is formed are inserted, whereby the unfixed toner image is fixed on the recording medium.

  Further, at least one of both ends of the fixing belt in the rotation axis direction is provided with a fixing member that fits into the opening and fixes the shape of the opening in a circular shape. The driving device applies a rotational driving force to the fixing belt via the fixing member.

JP 2005-249958 A

  An object of the present invention is to suppress a fixing belt rotating in a circumferential direction from moving in a direction away from a driving member that transmits a driving force to a fixing belt provided at one end of the fixing belt.

A fixing belt according to a first aspect of the present invention is disposed on the inner side of an outer peripheral surface that contacts a rotating member that is rotatably supported while rotating in the circumferential direction by a driving force from a driving member provided at one end. An inner peripheral surface that is slidable with the pressure member and is pressed by the pressure member and presses the outer peripheral surface against the rotating member, and is formed in an annular shape at a portion that contacts the pressure member on the inner peripheral surface. A triangular portion having a triangular cross-section, and a heat generating layer that is provided between the outer peripheral surface and the inner peripheral surface and generates heat when a magnetic field is applied, and has a first inner angle on one end side in the triangular portion B> A is satisfied, where A is the angle of A and the angle of the second inner angle on the other end side is B.

  A fixing belt according to a second aspect of the present invention is the fixing belt according to the first aspect, wherein a third inner angle that forms an inner angle of the triangular portion together with the first inner angle and the second inner angle is C. If °, C <90 ° is satisfied.

  A fixing belt according to a third aspect of the present invention is the fixing belt according to the first or second aspect, wherein the drive member is a circular adhesive portion that contacts the inner peripheral surface and adheres to the inner peripheral surface. And the triangular portion is also provided at a portion that contacts the adhesive portion.

A fixing device according to a fourth aspect of the present invention is provided at one end of the fixing belt according to any one of the first to third aspects and the fixing belt, and contacts the inner peripheral surface of the fixing belt, thereby A driving member that has a bonding portion that is bonded to the peripheral surface , transmits a driving force that rotates in the circumferential direction to the fixing belt via the bonding portion, and applies a magnetic field to the heat generation layer of the fixing belt to An electromagnetic induction heating device that generates heat from the heat generating layer, a recording medium that presses a recording medium on the outer peripheral surface of the fixing belt, a rotating member that is rotatably supported, and an inner side of the fixing belt. And a pressurizing member that pressurizes the rotating member.

  An image forming apparatus according to a fifth aspect of the present invention includes an image carrier on which an electrostatic latent image is formed on a surface, and a developing device that visualizes the electrostatic latent image formed on the surface of the image carrier as a toner image. A transfer device that transfers the toner image to a recording medium; and a fixing device that fixes the toner image transferred to the recording medium to the recording medium and has the fixing belt according to claim 1. It is characterized by providing.

  According to the fixing belt of the first aspect of the present invention, the fixing belt moves away from the driving member provided at one end when used in the image forming apparatus, as compared with the case without this configuration. Can be suppressed.

  According to the fixing belt of the second aspect of the present invention, the fixing belt moves away from the drive member provided at one end when used in the image forming apparatus, as compared with the case without this configuration. Can be further suppressed.

  According to the fixing belt of claim 3 of the present invention, when used in the image forming apparatus, the adhesive portion provided on the driving member and the inner peripheral surface of the fixing belt are compared with the case where the fixing belt is not provided. Can be prevented from peeling off.

  According to the fixing device of the fourth aspect of the present invention, the life of the fixing device can be extended when used in the image forming apparatus, as compared with the case where this configuration is not provided.

  According to the image forming apparatus of the fifth aspect of the present invention, the life of the image forming apparatus can be extended as compared with the case where this configuration is not provided.

2A and 2B are a cross-sectional view and an enlarged cross-sectional view illustrating a fixing belt, a drive gear, and the like employed in a fixing device according to an embodiment of the present invention. 2A and 2B are a perspective view and a front view showing a fixing belt, a driving gear and the like employed in the fixing device according to the embodiment of the present invention. 1 is a side view showing a fixing device according to an embodiment of the present invention. 1 is a cross-sectional view illustrating a fixing belt according to an embodiment of the present invention. 1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. 4 is a drawing showing liquid composition conditions used for electrolytic plating when manufacturing a fixing belt according to an embodiment of the present invention. (A) (B) It is sectional drawing which showed the shape of the triangular part of Example 1 which evaluated the fixing belt which concerns on embodiment of this invention. (A) (B) It is sectional drawing which showed the shape of the triangular part of Example 2 and Example 3 which evaluated the fixing belt which concerns on embodiment of this invention. (A) (B) It is sectional drawing which showed the shape of the triangular part of Example 4 and the comparative example 1 which evaluated the fixing belt which concerns on embodiment of this invention. (A) (B) It is sectional drawing which showed the shape of the triangular part of the comparative example 2 and the comparative example 3 evaluated as a comparison with the fixing belt which concerns on embodiment of this invention. 6 is a diagram illustrating an evaluation result of evaluating the durability of the fixing belt according to the embodiment of the present invention.

  An embodiment of a fixing device and an image forming apparatus in which an example of the fixing belt of the present invention is employed will be described with reference to FIGS.

(overall structure)
As shown in FIG. 5, the image forming apparatus 40 of the present invention includes a photosensitive drum 60 as an image holding member, a charging device 62 that charges the surface of the photosensitive drum 60, and a charged photosensitive drum 60. A laser scanner 64 and a mirror 58 as latent image forming means for forming a latent image on the surface, a rotary developing device 66 as developing means for developing the latent image with a developer to form a toner image, and a toner image The intermediate transfer body 68 and transfer roll 70 as transfer means for transferring to a transfer body, the fixing device 50 as fixing means for heating and fixing a toner image to a sheet member P as a recording medium, and the surface of the photosensitive drum 60 are cleaned. Cleaning device 74, neutralizing device 76 for neutralizing the surface of the photosensitive drum 60, sheet feeding unit 78 for storing the sheet member P, and sheet member P for the sheet feeding unit A paper feed roller 80 for sequentially feeding from 8, and registration rollers 82 for conveying the sheet member P fed one by one, the recording medium guide 84 for guiding the sheet member P, and includes at least a.

  Specifically, a charging device 62 that charges the surface of the photosensitive drum 60 in the direction of arrow A along the periphery of the photosensitive drum 60 (non-contact type), and a latent image formed on the surface of the photosensitive drum 60. A rotary developing device 66 that forms a toner image by applying toner to the image, and an intermediate transfer member 68 whose outer peripheral surface is in contact with the surface of the photosensitive drum 60 and is rotatable in both the arrow B direction and the arrow C direction. And a cleaning device 74 that cleans the surface of the photosensitive drum 60 after the toner image is transferred to the surface of the intermediate transfer member 68, and a static elimination device 76 that neutralizes the surface of the photosensitive drum 60.

  Further, on the surface of the photosensitive drum 60 between the charging device 62 and the developing device 66, a laser beam corresponding to the image information (signal) of each color is formed in order to form a latent image on the surface of the photosensitive drum 60. Irradiation from the laser scanner 64 through the mirror 58.

  Further, the developing device 66 includes developing devices (not shown) for the respective colors respectively containing toners of four colors of cyan, magenta, yellow, and black. When the developing device 66 rotates, the developing device 66 rotates. Each color toner is applied to the latent image formed on the surface to form a toner image.

  Further, a transfer roll 70 is provided around the intermediate transfer body 68 to which the toner image formed on the photosensitive drum 60 is transferred. The outer peripheral surface of the intermediate transfer body 68 and the surface of the transfer roll 70 are in contact with each other under pressure, and the sheet member P can be inserted through the contact portion in the direction of the arrow D. When the toner passes, the toner image held on the surface of the intermediate transfer member 68 is transferred to the sheet member P.

  In addition, a sheet feeding device 72 including a sheet feeding unit 78, a sheet feeding roller 80, a registration roller 82, and a recording medium guide 84 is provided upstream of the contact portion in the sheet member conveyance direction.

  Sheet feeding to the contact portion between the intermediate transfer body 68 and the transfer roll 70 is performed by feeding a sheet member P accommodated in the sheet feeding unit 78 by a push-up means (not shown) built in the sheet feeding unit 78. When the sheet member P comes into contact with the sheet feeding roller 80 and the sheet roller P and the registration roller 82 rotate, the sheet member P moves in the direction of arrow D along the recording medium guide 84. This is done by being conveyed.

(Main part configuration)
Next, the fixing device 50 will be described.

  As shown in FIG. 3, the fixing device 50 is detachably supported on the image forming apparatus main body and includes a heat generating layer 20B (see FIG. 3) that generates heat due to an eddy current generated when a magnetic field is applied. 20, a pressure roll 22 that forms a contact portion against the outer peripheral surface 30 of the fixing belt 20 and is rotatably supported, and an inner peripheral surface of the fixing belt 20 opposite to the side on which the pressure roll 22 is provided. There are provided a pressure pad 24 for pressing 32 from the inside and an electromagnetic induction heating device 26 for applying a magnetic field to the heat generating layer 20B of the fixing belt 20 by flowing an alternating current.

  Specifically, as shown in FIGS. 2A and 2B, at least one end of the cylindrical body 28 constituting the fixing belt 20 is a driving member that rotates the fixing belt 20 in the circumferential direction of the fixing belt 20. Drive gear 42 is provided. A convex flange 44 is integrally formed on the fixing belt 20 side of the drive gear 42 so as to be in surface contact with the inner peripheral surface 32 of the fixing belt 20. The outer surface of the flange portion 44 and the inner peripheral surface 32 of the fixing belt 20 are bonded with an adhesive, and a driving gear 42 that rotates by receiving a rotational force from a motor (not shown) is interposed via the flange portion 44. A rotational force is transmitted to the fixing belt 20.

  As shown in FIG. 4, the fixing belt 20 includes a heat-resistant resin layer 20A (base material) having a film thickness of 60 μm and a nickel layer having a film thickness of 0.5 μm (illustrated) from the inner peripheral surface 32 to the outer peripheral surface 30. Omitted), a heating layer 20B having a thickness of 10 μm, a protection layer 20C having a thickness of 9 μm for protecting the heating layer 20B, an elastic layer 20D having a thickness of 200 μm, and a release layer 20E having a thickness of 30 μm.

  Further, as shown in FIG. 1, the inner circumferential surface 32 of the fixing belt 20 is provided with a triangular portion 34 having a triangular cross section formed from one end portion to the other end portion.

  Further, when the angle of the first inner angle 36 on one end side (drive gear 42 side) of the triangular portion 34 is A ° and the angle of the second inner angle 38 on the other end side is B °, B> Satisfies A. Furthermore, when the angle of the third inner angle 46 that constitutes the inner angle of the triangular portion 34 together with the first inner angle 36 and the second inner angle 38 is C °, preferably C <90 °.

  On the other hand, as shown in FIG. 3, the pressure roll 22 has an elastic body layer 22B made of silicon rubber or the like formed on a base material 22A, and a release layer 22C made of a fluorine-based compound on the upper layer. Yes.

  Further, a pressure pad 24 that presses the inner peripheral surface 32 of the fixing belt 20 and locally increases the contact pressure is provided inside the fixing belt 20 at a position facing the pressure roll 22. The pressure pad 24 includes a contact head 24B that contacts the inner peripheral surface 32 of the fixing belt 20 and presses the contact portion, a contact pad 24C made of silicon rubber or the like that holds the contact head 24B, and a contact pad 24C. A supporting body 24A is provided.

  With this configuration, as shown in FIGS. 1A and 1B, the triangular portion 34 bites into the contact head 24 </ b> B, and a surface 48 (hereinafter referred to as a second inner angle 38 and a third inner angle 46). Is sometimes referred to as a “stopper surface”) so as to prevent the rotating fixing belt 20 from moving in the direction away from the drive gear 42 (in the direction of arrow C shown in FIG. 1). It has become.

  As shown in FIG. 3, an electromagnetic induction heating device 26 incorporating an electromagnetic induction coil (excitation coil) 26 </ b> A is provided at a position facing the pressure roll 22 with the fixing belt 20 as the center. The electromagnetic induction heating device 26 changes the magnetic field generated by applying an alternating current to the electromagnetic induction coil 26 </ b> A by an excitation circuit, and generates an eddy current in the heat generating layer 20 </ b> B of the fixing belt 20. This eddy current is converted into heat (Joule heat) by the electric resistance of the heat generating layer 20B, and as a result, the surface of the fixing belt 20 generates heat.

  Next, a method for manufacturing the fixing belt 20 will be described.

  An aluminum cylinder having an outer diameter of 30 mm and a length of 500 mm was used as the core, and a groove having a triangular cross section was formed in the circumferential direction of this surface by cutting. At this time, the triangular shape of the groove was processed so that the first inner angle 36, the second inner angle 38, and the third inner angle 46 of the triangular portion 34 described above were determined.

  Further, a silicone release agent (trade name: KS700, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the surface of the core, and baked at 300 ° C. for 1 hour.

  As shown in FIG. 4, an N-methylpyrrolidone solution of PI precursor (trade name: U varnish, manufactured by Ube Industries, solid content concentration: 18%, viscosity: about 5 Pa · s) After coating, the film was dried and fired to produce a heat resistant resin layer 20A as an endless belt having a film thickness of 60 μm and an outer diameter of 30 mm.

  Next, the outer peripheral surface of the heat resistant resin layer 20A is blasted and cleaned, and the outer peripheral surface is subjected to electroless nickel plating to form a nickel layer (not shown) of 0.5 μm. Next, the electroless nickel plating film is used as an electrode, and a heating layer 20B as a copper layer having a thickness of 10 μm is formed thereon by electrolytic plating.

  Further, a protective layer 20C having a thickness of 9 μm was formed as a nickel layer on the heat generating layer 20B by electrolytic plating under the liquid composition conditions shown in FIG. Furthermore, 200 μm of an elastic layer 20D as a silicon rubber elastic layer was applied on the protective layer 20C and left at 200 ° C. for 1 hour.

  Further, a fluororesin (PFA) dispersion paint (trade name: EN-710CL, manufactured by Mitsui DuPont Fluorochemical Co., Ltd.) is applied on the elastic layer 20D, and then left in an oven at 380 ° C. for 1 hour to apply the fluororesin coating. By firing the film, a release layer 20E as a PFA layer having a thickness of 30 μm is formed, and the fixing belt 20 is manufactured.

  Then, as shown in FIG. 1, one end of the fixing belt 20 was bonded to a flange portion 44 (see FIG. 2) formed on the drive gear 42. At this time, the one end portion side on the gear bonding side was made to coincide with the first inner angle 36 described above.

(Function)
Next, the operation of the image forming apparatus 40 will be described.

  As shown in FIG. 5, laser light corresponding to the color image information (signal) emitted from the laser scanner 64 is reflected by the mirror 58 and irradiated onto the surface of the photosensitive drum 60 charged by the charging device 62. As a result, a latent image is formed. Further, when the developing device 66 rotates, toner of each color is applied to the latent image formed on the surface of the photosensitive drum 60, and the latent image formed on the surface of the photosensitive drum 60 is visualized as a toner image. The

  The toner images of the respective colors formed on the surface of the photosensitive drum 60 are brought into contact with the photosensitive drum 60 and the intermediate transfer body 68 by a bias voltage applied between the photosensitive drum 60 and the intermediate transfer body 68. The toner image of each color is transferred onto the outer peripheral surface of the intermediate transfer member 68 so as to coincide with the image information.

  The intermediate transfer member 68 on which the color toner image is transferred to the outer peripheral surface in this way rotates in the direction of arrow C, and the toner image is fed at the contact portion between the transfer roll 70 and the intermediate transfer member 68. Thus, the sheet is transferred to the sheet member P conveyed to the contact portion.

  The sheet member P to which the toner image has been transferred moves in the direction of arrow D and is heated and fixed by the fixing device 50, so that the toner image is fixed to the sheet member P.

Specifically, the surface of the fixing belt 20 is heated by an electromagnetic induction heating device 26 provided to face the surface. Fixing belt 20 whose surface is sufficiently heated is rotated in the arrow V ₁ direction heating, at the contact portion between the pressure roll 22, by heating and melting the toner image of the sheet member P is inserted in the arrow D direction To settle.

  The sheet member P on which the color image is formed in this way is further conveyed in the direction of the arrow D and is discharged to the outside of the image forming apparatus 40.

  Specifically, as shown in FIG. 2, a fixing mechanism in which a driving gear 42 that receives rotational force from a motor (not shown) and is rotationally driven is bonded and fixed to the flange portion 44 via the flange portion 44 with an adhesive. A rotational force is transmitted to the belt 20, and the fixing belt 20 rotates in the circumferential direction.

  Therefore, as shown in FIG. 1, it is conceivable that the fixing belt 20 moves in the arrow C direction away from the drive gear 42 when the fixing belt 20 rotates in the circumferential direction.

  However, as described above, the triangular portion 34 of the fixing belt 20 bites into the contact head 24B. Further, the stopper surface 48 contacts the contact head 24 </ b> B and suppresses the movement of the fixing belt 20 in the direction away from the drive gear 42.

  Further, since the triangular portion 34 is also formed on the inner peripheral surface 32 of the fixing belt 20 that is bonded to the flange portion 44 with an adhesive, the bonding area between the fixing belt 20 and the flange portion 44 is widened, and the adhesive strength is increased. By improving, the fixing belt 20 is prevented from moving away from the drive gear 42.

  Next, using the fixing belt 20 in this configuration, the durability of the fixing belt 20 was confirmed by the following test.

<Evaluation>
-Fixing device-
The fixing belt obtained by the above-described manufacturing method was mounted on a fixing device having a pressure pad, a fixing belt, a pressure roll, and an electromagnetic induction device (excitation coil) and evaluated. Details of the fixing device used in the evaluation will be described below.

  The pressure pad includes a support that rotatably supports the fixing belt via fixing belt driving gears at both ends of the fixing belt, and a contact pad having a pressure rubber pad mounting portion having a diameter smaller than the inner diameter of the fixing belt. And a pressing contact head provided with a sliding sheet for reducing the frictional resistance with the inner peripheral surface of the fixing belt on the side contacting the inner peripheral surface of the fixing belt.

  In assembling the fixing device, the pressure pad, the fixing belt, and the pressure roll were arranged as follows.

  First, for the pressure pad, after the contact head for pressure is fixed to the contact pad of the support, the drive gear on the side where the drive gear for inserting the fixing belt and driving the fixing belt in advance is fixed Was attached to the fixing belt support. Subsequently, a driving gear was also attached to the end portion on the release side of the fixing belt. Subsequently, a part of the outer circumferential surface of the fixing belt is brought into contact with the pressure roll, and a load is applied between the pressure roll shaft and the pressure pad, so that the pressure pad contact head and pressure are applied. The roll was brought into contact with the fixing belt.

  As a material constituting the fixing belt fixing gear and the folder, a resin (PPS) that does not generate an induced electromotive force due to an alternating current and has heat resistance in a fixing temperature region was used.

  The exciting coil used in the fixing device is a litz wire in which 16 φ0.5 mm copper wires that are insulated from each other are bundled, and this is longer than the width of the fixing belt and the circumferential length of the fixing belt. The gap between the exciting coil and the fixing belt is made uniform by winding it so that it has a width that covers 1/6 to 1/4 of that of the fixing belt, and by providing a curvature that follows the curvature of the fixing belt. Formed. The fixing coil was fixed on the outer peripheral surface of the fixing belt so that the gap between the exciting coil and the fixing belt was 2 mm.

  At the time of fixing, an alternating current is passed through the exciting coil by an exciting circuit to generate a magnetic field around the exciting coil. Therefore, when the generated magnetic field crosses the metal heating layer of the fixing belt, an eddy current is generated in the metal heating layer that generates a magnetic field in a direction that cancels the magnetic field crossed by electromagnetic induction. Thereby, heat generation according to the eddy current value at this time and the resistance of the metal heating layer is obtained.

  On the other hand, the pressure roll is formed by providing a foamed silicon rubber layer having a thickness of 12 mm as an elastic layer on a solid shaft having an outer diameter of 16 mm, and further covering this layer with a PFA tube having a thickness of 30 μm.

  Specifically, this pressure roll was produced as follows. First, a fluororesin tube having an outer diameter of 50 mm, a length of 340 mm, and a thickness of 30 μm, in which an adhesive primer was applied to the inner peripheral surface of the PFA tube, and a solid shaft were set in a molding die. Subsequently, after injecting liquid foamed silicon rubber between the fluororesin tube and the solid shaft so that the layer thickness is 2 mm, the silicon rubber is vulcanized and foamed by heat treatment (150 ° C. × 2 hrs) to form an elastic layer. The pressure roll was produced by forming.

  As an evaluation device, a motor was connected to the drive gear, and the fixing belt was driven to drive the pressure roll to convey the sheet member.

-Evaluation method-
The evaluation method is as follows. In the above-described fixing device, a paper passing test using J paper (A4 size vertical feed) manufactured by Fuji Xerox Co., Ltd. was performed up to 400,000 sheets at a speed of 20 sheets per minute until the metal heating layer cracked. Was evaluated. As a goal, from the viewpoint of practicality, the fixing belt cannot be removed from the gear member fixed to one end of the fixing belt up to 400 kPV (sheets).

Example 1
7A and 7B, the first inner angle 36 of the triangular portion 34 of the first embodiment is 45 °, the second inner angle 38 is 90 °, and the third inner angle 46 is The angle is 45 °.

  As shown in FIG. 11, in Example 1, it can be seen that the fixing belt did not come off from the gear member up to 800 kPV (sheets). That is, the target 400 kPV (sheets) is satisfied.

(Example 2)
As shown in FIG. 8A, the first inner angle 36 of the triangular portion 34 of the second embodiment is 45 °, the second inner angle 38 is 60 °, and the third inner angle 46 is 75 °. Has been.

  As shown in FIG. 11, in the second embodiment, it is understood that the fixing belt is not detached from the gear member up to 600 kPV (sheets). That is, the target 400 kPV (sheets) is satisfied.

(Example 3)
As shown in FIG. 8B, the first inner angle 36 of the triangular portion 34 of the third embodiment is 45 °, the second inner angle 38 is 50 °, and the third inner angle 46 is 85 °. Has been.

  As shown in FIG. 11, in the third embodiment, it is understood that the fixing belt is not detached from the gear member up to 480 kPV (sheets). That is, the target 400 kPV (sheets) is satisfied.

Example 4
As shown in FIG. 9A, the first inner angle 36 of the triangular portion 34 of the fourth embodiment is 30 °, the second inner angle 38 is 45 °, and the third inner angle 46 is 105 °. Has been.

  As shown in FIG. 11, in Example 4, it can be seen that the fixing belt did not come off from the gear member up to 400 kPV (sheets). That is, the target 400 kPV (sheets) is satisfied.

(Comparative Example 1)
As shown in FIG. 9B, the first interior angle of the triangular portion of Comparative Example 1 is 45 °, the second interior angle is 45 °, and the third interior angle is 90 °.

  As shown in FIG. 11, in Comparative Example 1, the fixing belt was detached from the gear member at 360 kPV (sheets). That is, the target 400 kPV (sheets) could not be satisfied.

(Comparative Example 2)
As shown in FIG. 10A, the first interior angle of the triangular portion of Comparative Example 2 is 50 °, the second interior angle is 45 °, and the third interior angle is 85 °.

  As shown in FIG. 11, in Comparative Example 2, the fixing belt was detached from the gear member at 240 kPV (sheets). That is, the target 400 kPV (sheets) could not be satisfied.

(Comparative Example 3)
As shown in FIG. 10B, the first interior angle of the triangular portion of Comparative Example 3 is 90 °, the second interior angle is 45 °, and the third interior angle is 45 °.

  As shown in FIG. 11, in Comparative Example 3, the fixing belt was detached from the gear member at 100 kPV (sheets). That is, the target 400 kPV (sheets) could not be satisfied.

20 fixing belt 20B heat generating layer 22 pressure roll (rotating member)
24 Pressure pad (Pressure member)
26 Electromagnetic induction heating device 28 Cylindrical body 30 Outer peripheral surface 32 Inner peripheral surface 34 Triangular portion 36 First inner angle 38 Second inner angle 40 Image forming device 42 Drive gear (drive member)
44 Flange (bonded part)
46 Third interior angle 50 Fixing device 60 Photosensitive drum (image carrier)
66 Developing device 68 Intermediate transfer member (transfer device)
70 Transfer roll (transfer device)

Claims (5)

An outer peripheral surface that rotates in a circumferential direction with a driving force from a driving member provided at one end, and that contacts a rotating member that is rotatably supported
An inner peripheral surface that is slidable with a pressure member disposed inside, and is pressed by the pressure member to press the outer peripheral surface against the rotating member;
A triangular portion having a triangular cross section is formed in a portion of the inner peripheral surface that contacts the pressure member,
A heating layer provided between the outer peripheral surface and the inner peripheral surface and generating heat when a magnetic field is applied;
With
A fixing belt that satisfies B> A when the angle of the first inner angle on one end side of the triangular portion is A ° and the angle of the second inner angle on the other end side is B °.   2. The fixing belt according to claim 1, wherein C <90 ° is satisfied when an angle of a third inner angle that constitutes an inner angle of the triangular portion together with the first inner angle and the second inner angle is C °.   3. The drive member according to claim 1, wherein the drive member is provided with a circular adhesive portion that contacts the inner peripheral surface and adheres to the inner peripheral surface, and the triangular portion is also provided at a portion that contacts the adhesive portion. The fixing belt described. The fixing belt according to any one of claims 1 to 3,
The fixing belt is provided at one end of the fixing belt and has an adhesive portion that abuts against the inner peripheral surface of the fixing belt and adheres to the inner peripheral surface, and a driving force that rotates in the circumferential direction is applied to the fixing belt through the adhesive portion. A drive member that transmits to the belt;
An electromagnetic induction heating device that generates a heat by applying a magnetic field to the heat generating layer of the fixing belt;
A rotating member that pressurizes the recording medium on the outer peripheral surface of the fixing belt and is rotatably supported
A pressure member disposed inside the fixing belt and pressurizing the fixing belt toward the rotating member;
A fixing device detachable from the apparatus main body. An image carrier on which an electrostatic latent image is formed on the surface;
A developing device for visualizing the electrostatic latent image formed on the surface of the image carrier as a toner image;
A transfer device for transferring the toner image to a recording medium;
Fixing the toner image transferred to the recording medium to the recording medium, and a fixing device having the fixing belt according to any one of claims 1 to 3,
An image forming apparatus comprising:

Images