JP2015069124A - Image heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image heating device that can correct the posture of a belt, and prevent a shift movement of the belt.SOLUTION: An image heating device includes: an inner surface facing part that faces an inner surface of a belt at an end of the belt in a generatrix direction; a correction mechanism that pushes the inner surface of the belt with the inner surface facing part to correct the posture of the belt by moving the inner surface facing part upstream in a conveyance direction of a recording material in accordance with a shift movement of the belt to the generatrix direction; and an inclination regulation mechanism that regulates the inclination of the inner surface facing part.

Description

  The present invention relates to an image heating apparatus that has a cylindrical flexible rotating body and heats an image formed on a recording material. In particular, the present invention relates to an image heating apparatus suitable for use as a fixing device mounted on an image forming apparatus that forms a toner image on a recording material using electrophotographic recording technology.

  In an image heating apparatus using a flexible rotating body typified by a fixing device, there is often a problem that the rotating body moves in the generatrix direction while the rotating body rotates. In order to restrict this shifting, a regulating member that regulates the shifting of the rotating body may be provided at a position facing the end face of the rotating body. Patent Document 1 discloses an image heating apparatus having such a regulating member.

JP2011-248285A

  By the way, recent image forming apparatuses are required to increase speed and save energy. With this requirement, the rotational speed of the rotating body also increases, and the pressure applied to the end face of the rotating body when the rotating body is in contact with the regulating member is increased. In addition, in order to suppress the heat capacity of the rotating body, the rotating body is also made thinner and smaller in diameter. For this reason, the pressure per unit area applied to the rotating body end face is increased. In addition, in recent years, the image forming apparatus is also required to have a long life, and accordingly, the time for the end face of the rotating body to shift and rub against the regulating member is also increased. As described above, with the improvement in performance required for the image forming apparatus, the end face of the rotating body is likely to be scraped, and the durability of the rotating body has become insufficient, and further improvement of the mechanism that restricts the displacement of the rotating body is achieved. Is required.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an image heating apparatus that can improve the decrease in durability of a flexible rotating body.

  In order to solve the above-described problems, the present invention provides a cylindrical flexible rotating body that rotates while contacting an image-carrying recording material, and an inner surface of the rotating body at an end portion in the generatrix direction of the rotating body. In the image heating apparatus having an inner surface facing portion facing each other, the inner surface facing portion is moved upstream in the conveyance direction of the recording material by moving the inner surface facing portion in accordance with the movement of the rotating body in the bus direction. It has a correction mechanism that pushes the inner surface of the rotating body and corrects the posture of the rotating body, and an inclination restricting mechanism that restricts the inclination of the inner surface facing portion.

  According to the present invention, it is possible to suppress scraping of the end face of the flexible rotating body.

Cross section of image forming apparatus Cross section of image heating device Perspective view and sectional view of the inside of the image heating apparatus The perspective view and sectional drawing of the correction mechanism of Example 1 Perspective view of movable member and holding member Cross section of correction mechanism Operation explanatory diagram of the correction mechanism Illustration explaining the force applied to the belt The figure explaining the mechanism which controls the attitude | position of a movable member The figure which shows the modification of Example 1. The figure which shows Example 2. The figure which shows the modification of Example 2. The figure which shows the modification of Example 2.

Example 1
FIG. 1 is a cross-sectional view of an electrophotographic printer 100 (image forming apparatus) equipped with a fixing device 1 which is an image heating device. The full color toner image formed by superimposing the four color toner images in the image forming unit 101 is transferred by the transfer unit 102 to the recording material P fed from the paper feeding unit. The toner image transferred to the recording material P is heated and fixed to the recording material by the fixing device 1. The fixed recording material P is discharged to the paper discharge tray 103. In the case of double-sided printing, after transferring and fixing the toner image on one side of the recording material, the recording material is switched back and conveyed to the double-sided conveyance path 104, and the same operation as the first side processing is performed on the second side of the recording material. Image formation. Since these image forming operations are well known, a detailed description thereof will be omitted.

  2 is a cross-sectional view showing an outline of the fixing device 1. FIG. 3 is a perspective view of the inside of the fixing device (FIG. 3A) and a cross-sectional view of the inside of the fixing device when the fixing device is viewed from the recording material discharge side. FIG. 3B). The arrow S indicates the conveyance direction of the recording material P, and the broken line X indicates the center in the longitudinal direction of the fixing device. In the fixing device of this example, the broken line X is a conveyance reference of the recording material P. Regardless of the size of the recording material P, the recording material P is conveyed with the center of the recording material width direction aligned with the broken line X.

  The fixing device 1 includes a heating unit 2, a roller 3 that forms a fixing nip portion together with the heating unit 2, a conveyance roller 4 that conveys a recording material that has been subjected to a fixing process, and the like. The heating unit 2 includes a cylindrical flexible rotating body (cylindrical belt, cylindrical film) 9 (hereinafter referred to as a belt 9), and a heater 5 that contacts the inner surface of the belt 9 and heats the belt. Furthermore, the heating unit 2 includes a heater holder 6 that holds the heater 5, a stay 8 that maintains the rigidity of the heating unit, and the like. In this example, the heater 5, the heater holder 6, and the stay 8 constitute a backup unit that contacts the inner surface of the belt 9 in the direction of the bus line of the belt. There is no tension roller on the inner surface of the belt 9, and the belt 9 is not stretched. The roller 3 has a rubber layer and forms a fixing nip portion N for nipping and conveying the recording material together with the backup unit via the belt 9. The roller 3 is driven by a motor (not shown) via a gear 61, and the belt 9 rotates following the rotation of the roller 3.

  As shown in FIG. 3A, the frame 13 of the fixing device is provided with a U-shaped recess for mounting the bearing of the roller 3, and two bearings provided at the shaft end of the roller 3. Is held in this recess. Correcting mechanisms 110L and 110R for correcting the shift of the belt 9 are provided at both ends of the backup unit. By arranging the correction mechanism at this position, the correction mechanisms 110L and 110R face the end face of the belt 9. The correction mechanisms 110L and 110R have a holding member 112 described later. The heating unit 2 is held by the frame 13 by mounting the groove 112f (see FIG. 7A) provided in the holding member 112 in the U-shaped recess of the frame 13 like the roller 3. Pressure is applied to the upper surface 112 c (see FIG. 4A) of the holding member 112 by the compression spring 7. Due to the pressure of the spring 7, the heater 5 is urged toward the roller 3 through the holding member 112, the stay 8, and the heater holder 6. As a result, the rubber layer of the roller 3 is compressed, and the backup unit and the roller 3 form the fixing nip portion N via the belt 9. The recording material P carrying the toner image is nipped and conveyed at the fixing nip portion N while being in contact with the belt 9. During this period, the toner image is heated by the heater 5 via the belt 9 and fixed on the recording material P.

  The belt 9 of this example has a heat-resistant resin base layer (specific material is polyimide), a fluororesin surface layer, and a rubber layer (silicone rubber layer) provided between the base layer and the surface layer. . The material of the base layer may be a metal such as stainless steel or nickel, and may be configured without the rubber layer as necessary.

  As shown in FIG. 3B, the heater 5 has an elongated shape in the longitudinal direction of the fixing device (in the bus line direction of the belt 9). The heater 5 is a ceramic heater in which a heating resistor is printed on a ceramic substrate, and electric power is supplied through a power supply connector 62. The temperature of the heater 5 is monitored by a temperature detection element (not shown), and the power of the heater 5 is controlled so that the temperature detected by the temperature detection element maintains the target temperature. The heater holder 6 is formed by molding a heat-resistant resin such as LCP (Liquid Crystal Polymer) or PPS (Polyphenylene Sulfide). The heater holder 6 is provided with a groove for fitting the heater 5, and the heater 5 is held in the longitudinal direction by fitting the heater 5 into the groove. The stay 8 has a U-shaped cross section and is made of metal (iron in this example). The stay 8 is in contact with the holder 6 in the longitudinal direction and reinforces the holder 6.

  Next, correction mechanisms 110R and 110L that correct the shift of the belt 9 will be described with reference to FIGS. Since the correction mechanisms 110R and 110L have substantially line symmetrical shapes with respect to the conveyance reference X of the recording material P, the correction mechanism will be described mainly using the correction mechanism 110R (partly using 110L).

  4A is a perspective view of the correction mechanism 110L, and FIG. 4B is a cross-sectional view of the correction mechanism 110R as viewed from the upstream side in the recording material conveyance direction. 5A is a perspective view of the movable member 111 described later, and FIG. 5B is a perspective view of the holding member 112 that holds the movable member 111. Further, FIG. 6 is a view when the correction mechanism 110R is viewed from the direction V2 in FIG. 4B, and FIGS. 7 and 8 are diagrams for explaining a mechanism for correcting the posture of the belt by the correction mechanism.

  The correction mechanism 110R includes a movable member 111, a holding member 112 that holds the movable member 111, and a compression spring (biasing member) 14 that biases the movable member 111. As described above, the holding member 112 is fitted into the U-shaped recess of the frame 13 of the fixing device. Thereby, the position of the holding member 112 in the heater longitudinal direction and the position of the holding member 112 in the recording material conveyance direction are substantially determined. Since the holding member 112 is biased toward the roller 3 by the spring 7, it is in a substantially fixed state.

  The movable member 111 is a component that is movably engaged with the holding member 112. The movable member 111 is in contact with a notch provided at the longitudinal end of the stay 8, and a slight gap is provided between the upper portion of the movable member 111 and the holding member 112. As shown in FIG. 4A, the movable member 111 has an end surface facing portion 111 a that faces the end surface of the belt 9. When the belt 9 moves toward the generatrix, the end surface of the belt 9 abuts against the end surface facing portion 111a. The movable member 111 has an inner surface facing portion 111 c that faces the inner surface of the end portion of the belt 9. A slight clearance is provided between the inner surface of the belt 9 and the inner surface facing portion 111c, and the inner surface facing portion 111c also has a function of guiding the inner surface of the belt 9 when the belt rotates.

  As shown in FIG. 5A, the movable member 111 has a convex portion 111b extending in an oblique direction with respect to the heater longitudinal direction. On the other hand, as shown in FIG. 5B, the holding member 112 has a concave portion (guide portion) 112b extending in a direction oblique to the longitudinal direction of the heater. When the movable member 111 and the holding member 112 are combined, the convex portion 111 b of the movable member 111 is accommodated in the concave portion 112 b of the holding member 112. With this configuration, the movable member 111 is slidably held along the recess 112 b of the holding member 112. Reference numeral 14 denotes a compression spring that urges the movable member 111 in a direction away from the seating surface 112 a of the holding member 112.

  Next, the operation of the correction mechanism 110 will be described with reference to FIGS. 6 and 7A show the state of the correction mechanism when the end face of the belt 9 is not in contact with the end face facing portion 111a. When the belt 9 is driven to rotate by the rotation of the roller 3, the belt 9 is in contact with the inner surface facing portion 111 c of the movable member 111 in a region upstream of the heater 5 in the belt rotation direction. On the other hand, they are separated from each other in the region downstream of the heater 5 in the belt rotation direction.

  When the end surface of the belt 9 is not in contact with the end surface facing portion 111a, the movable member 111 urged by the spring 14 is located at the position farthest from the seat surface 112a inside the holding member 112. At this time, the convex portion 111b of the movable member 111 abuts against the first stopper portion 112d of the holding member 112, and even if the convex portion 111b is biased by the spring 14, the movement of the movable member 111 is restricted and the position is determined.

  As shown in FIG. 7A, when the end surface of the belt 9 is not in contact with the end surface facing portion 111a, the distance between the end surface of the belt 9 and the end surface facing portion 111a of the movable member 111 is D1. Further, the distance from the seating surface 112a of the holding member 112 to the end surface facing portion 111a of the movable member 111 is D2.

  In FIG. 7B, the belt 9 moves toward the M1 direction, the end surface of the belt 9 contacts the end surface facing portion 111a, and the belt 9 resists the urging force of the spring 14 to move the movable member 111 in the M1 direction. The state pressed to is shown.

  When the belt 9 moves toward the movable member 111 due to, for example, a relative misalignment between the roller 3 and the belt 9, the end surface of the belt 9 contacts the movable member 111. When the belt 9 moves further, the belt 9 pushes the movable member in the M1 direction against the urging force of the spring 14, and the movable member 111 moves by using the force of the belt to move. Since the convex portion 111b of the movable member 111 moves along the concave portion 12b of the holding member 112, the movable member 111 moves in the M2 direction. And the movement of the movable member 111 stops when the convex part 111b collides with the 2nd stopper part 112g of the recessed part 112b. At this time, as shown in FIG. 7B, the distance from the seating surface 112a of the holding member 112 to the end surface facing portion 111a of the movable member 111 is D3 (<D2). Further, the movable member 111 has moved a distance D4 upstream in the recording material conveyance direction S compared to the state of FIG.

  As described above, when the belt 9 is rotating, the inner surface of the belt 9 is in contact with the inner surface facing portion 111 c of the movable member 111. Therefore, when the movable member 111 moves upstream in the recording material conveyance direction S as shown in FIG. 7B, the inner surface facing portion 111c pushes the inner surface of the belt 9, and as a result, the belt end on the correction mechanism 110R side is moved. It moves to the upstream side in the recording material conveyance direction S. On the other hand, since the correction mechanism 110L located on the opposite side to the side where the correction mechanism 110R is located with respect to the heater longitudinal direction is not pushed by the end face of the belt 9, the movable member of the correction mechanism 110L does not move.

  When the moving direction of the belt 9 is reversed, that is, when the belt hits the correction mechanism 110L, only the movable member in the correction mechanism 110L moves upstream in the recording material conveyance direction S. By this movement, the belt end on the correction mechanism 110L side moves to the upstream side in the recording material conveyance direction S.

  In this way, when the belt 9 moves in the heater longitudinal direction (belt bus direction) and hits one of the two correction mechanisms 110R and 110L, only the end of the belt 9 on the downstream side in the shift direction is recorded. It receives force toward the upstream of the material conveyance direction. By this principle, the alignment of the belt 9 with respect to the roller 3 is changed, the posture of the belt is corrected, the belt moves in a direction away from the movable member (the direction opposite to the direction M1 shown in FIG. 7B), and the belt 9 The force applied to the end face is suppressed. Thereby, damage to the belt can be suppressed. Note that the movable member 111 is biased by the spring 14 as described above. For this reason, when the belt 9 moves in the direction opposite to the direction M1 from the state shown in FIG. 7B, the movable member 111 is moved to the position shown in FIG. 7A, or FIG. 7A and FIG. It is pushed back to the position between b).

  Next, the principle of reducing the stress applied to the end face of the belt 9 will be further described with reference to FIGS. 8A to 8C. FIGS. 8A to 8C are views of the heating unit 2 and the roller 3 as viewed from the belt 9 side. FIG. 8A shows a state in which the belt is shifted and FIG. 8B shows a state in which the belt is not moved. FIG. 8C shows a state in which the inclination of the belt 9 is corrected.

  In general, the cause of the belt 9 moving in the direction of the bus is due to misalignment between the roller 3 and the belt 9. FIG. 8A shows a state in which the above-described misalignment has occurred. The belt end on the correction mechanism 110L side is downstream in the recording material conveyance direction S, and the belt end on the correction mechanism 110R side is in the recording material conveyance direction S. It represents the state of tilting upstream. As shown in FIG. 8A, the belt 9 receives a force F by the rotation of the roller 3. The force F can be decomposed into a generatrix direction F1 of the belt 9 and a direction F2 orthogonal thereto, and the belt 9 moves toward the correction mechanism 110L by the force F1. When the belt 9 contacts the movable member 111 of the correction mechanism 110L and pushes the movable member 111 (FIG. 8B), the movable member 111 is guided by the holding member 112 and moves upstream in the recording material conveyance direction S. . As the movable member 111 moves, the posture of the belt 9 is corrected as shown in FIG. Since the misalignment between the roller 3 and the belt 9 is eliminated, the force F and the angle of the belt 9 in the bus line direction change. As a result, the force F1 is reduced (F1 → F1 ′), and the stress applied to the end face of the belt 9 is also reduced.

  As described above, since the stress applied to the end face of the belt 9 can be reduced, wear of the end face of the belt 9 can be suppressed.

  On the other hand, when the position of the center of the roller portion of the pressure roller 3 in the longitudinal direction is shifted from the position of the sheet S width center, the conveying force applied to the belt 9 due to the rotation of the pressure roller 3 becomes uneven at both ends. . For example, as shown in FIG. 8D, when the sheet S is shifted to the correction mechanism 110R side, the area where the pressure roller 3 directly contacts the belt 9 is longer on the correction mechanism 110L side. Since the frictional force between the pressure roller 3 and the belt 9 is greater than the frictional force between the paper and the belt 9, the rotational force of the belt 9 by the pressure roller 3 is corrected more than the rotational force Fr applied to the correction mechanism 110R side. The rotational force Ff on the mechanism 110L side becomes larger. As a result, the belt end on the correction mechanism 110R side is delayed in rotation and moved to the upstream side in the sheet conveying direction by the force T. At this time, the belt end on the correction mechanism 110R side presses the movable member 111 upstream in the sheet conveying direction. As shown in FIG. 9, the pressed movable member 111 starts to tilt to rotate in the W direction around the contact point P between the concave portion 112b and the convex portion 111b. When the force T exceeds the limit force Tlimit that causes the movable member 111 to be displaced, the movable member 111 is inclined and the hatched portion Y of the movable member 111 is displaced upstream in the sheet conveying direction. As in FIG. 8A, the alignment of the belt 9 with respect to the rotation axis (the chain line) of the pressure roller is shifted. Therefore, in order to prevent the posture of the movable member 111 from being inclined, an inclination restriction mechanism for restricting the inclination of the movable member (inner surface facing portion) is provided. Specifically, the first engaging portion 111 h is provided in the end surface facing portion 111 a of the movable member 111, and the second engaging portion 112 h is provided in the holding member 112. In other words, the tilt regulating mechanism includes a first engagement portion provided at the end surface facing portion and a second engagement portion provided at the holding member and engaged with the first engagement portion.

  When the movable member 111 starts to tilt, the first engaging portion 111h and the second engaging portion 112h come into contact with each other. As a result, the movable member 111 is prevented from further tilting. In the state where the first engagement portion 111h and the second engagement portion 112h are in contact with each other and the inclination of the movable member is restricted, the convex portion of the movable member is at a point P that is the center of rotation of the movable member in the W direction. 111b and the recessed part (guide part) 112b of a holding member contact | abut. However, in the W direction, the convex portion and the concave portion are separated from each other at the other portion (that is, near the point Q in FIG. 9). According to the experiment, it was possible to increase the limit force Tlimit by which the movable member is displaced by 1.8 times when the Y portion of the movable member is pressed upstream in the transport direction by providing the tilt regulating mechanism. In this embodiment, the contact surfaces of the two engaging portions are formed in a surface shape parallel to the sheet conveyance direction, but the contact surface may be formed in a shape inclined with respect to the conveyance direction. As a result, the alignment of the belt 9 can be maintained without tilting the posture of the movable member 111, and the belt deviation can be continuously regulated while reducing the stress applied to the belt end surface.

  In the present embodiment, the sheet S is conveyed in a state shifted from the normal position in the width direction, and the rotational force F transmitted from the pressure roller 3 to the belt 9 becomes non-uniform in the longitudinal direction, and the side where the belt is not approached. An effect can be obtained when a force T that causes the belt end to move upstream in the sheet conveying direction is generated.

  Further, the shapes of the first engaging portion and the second engaging portion may be shapes as shown in FIG. In FIG. 10, the holding member 212 of the correction mechanism 210R is provided with a rib-shaped portion (second engaging portion) 212h, the movable member 211 is provided with a protruding portion (first engaging portion) 211h, and the protruding portion 211h is rib-shaped. It is the structure latched to the part 212h. Even in such a shape, it is possible to reliably prevent the movable member on the side where the belt is not moved from being displaced to the upstream side in the sheet conveying direction by the pressing force from the belt. In FIG. 10, 211b, 212b, and 212d have the same functions as 111b, 112b, and 112d in FIG.

(Example 2)
Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, description of the part which overlaps with Example 1 is abbreviate | omitted. In the first embodiment, the holding member regulates the inclination of the movable member. However, in this embodiment, parts other than the holding member regulate the inclination of the movable member.

  In the example shown in FIG. 11, the movable member 311 is provided with a projection (first engagement portion) 311 h, and the pressure stay 308 is provided with a groove (second engagement portion) 308 h that engages the projection 311 h. It has been. In FIG. 11, when the belt 9 is close to the correction mechanism 310L opposite to the correction mechanism 310R, the movable member 311 in the correction mechanism 310R is urged by the urging member 14, hits the pressure stay 308, and protrudes. The part 311h and the groove part 308h are engaged.

  As in the first embodiment, when a force T for shifting the alignment of the belt 9 is applied to the pressure roller 9, the movable member 311 in the correction mechanism 310R is pressed upstream in the sheet conveying direction. The pressed movable member 311 tends to incline in the W direction around the contact point P between the slide rib-shaped portion 311b and the guide portion 312b. At this time, the protrusion 311h provided on the movable member 311 and the groove 308h provided on the pressure stay 308 are engaged, thereby preventing the movable member 311 from being inclined.

  In the example illustrated in FIG. 12, a protrusion (second engagement portion) 408 h is provided on the downstream side surface of the pressure stay 408 in the sheet conveyance direction, and the protrusion 408 h is a contact portion (first engagement portion) of the movable member 411. ) Abuts with 411h to prevent the movable member 411 from tilting.

  In the example shown in FIG. 13, a protrusion (second engagement portion) 506 h is provided on the downstream side surface in the sheet conveying direction of the heater holder 506 that holds the ceramic heater 505, and the protrusion 506 h is a butting portion (first portion) of the movable member 511. One engaging portion) 511h to prevent the movable member 511 from being inclined. 11 to 13, 311b, 312b, 411b, 412b, 511b, and 512b have the same functions as 111b and 112b in FIG.

  In the first and second embodiments described above, the correction mechanism is provided at a position facing the both ends of the belt. However, the belt shift direction is set in one direction in advance, and the correction mechanism described above is disposed on the belt shift direction side. The structure provided only in may be sufficient. In this example, the description has been made on the assumption that the length of the belt is shorter than the span between the two movable members. However, a configuration in which the length of the belt is substantially the same as the span between the two movable members, that is, a configuration in which both ends of the belt are always in contact with the two movable members may be employed. Furthermore, although the configuration in which the inner surface facing portion and the end surface facing portion are a single component as a movable member has been described, a configuration in which the inner surface facing portion and the end surface facing portion are separate components may be used.

9 Belt 110R, 110L Correction mechanism 111 Movable member 112 Holding member

Claims (14)

A cylindrical flexible rotating body that rotates in contact with a recording material carrying an image;
An inner surface facing portion facing an inner surface of the rotating body at an end in a generatrix direction of the rotating body;
In an image heating apparatus having
By moving the inner surface facing portion upstream in the conveying direction of the recording material in accordance with the movement of the rotating body toward the generatrix direction, the inner surface of the rotating body is pushed by the inner surface facing portion, and the posture of the rotating body is changed. A correction mechanism to correct,
An inclination regulating mechanism for regulating the inclination of the inner surface facing portion;
An image heating apparatus comprising:   The correction mechanism has an end face facing portion that faces the end face of the rotating body, and when the rotating body moves closer and the rotating body contacts the end face facing portion, the rotating body exerts a force that presses the end face facing portion. The image heating apparatus according to claim 1, wherein the inner surface facing portion moves to the upstream side by use of the image heating device.   3. The biasing member according to claim 2, further comprising a biasing member that biases the inner surface facing portion so that the inner surface facing portion returns to its original position when the end surface of the rotating body is separated from the end surface facing portion. Image heating device.   The holding member for movably holding the inner surface facing portion is provided, and the holding member is provided with a guide portion for guiding the inner surface facing portion to move to the upstream side. The image heating apparatus according to any one of 1 to 3.   5. The image heating apparatus according to claim 1, wherein the correction mechanism is provided at each end of the rotating body in the generatrix direction. 6.   The image heating apparatus according to any one of claims 2 to 5, wherein the inner surface facing portion and the end surface facing portion constitute one component and constitute a movable member.   The tilt restricting mechanism includes a first engagement portion provided on the movable member and a second engagement portion provided on the holding member and engaged with the first engagement portion. The image heating apparatus according to claim 6.   The image heating apparatus according to claim 7, wherein the first engagement portion is provided in the end surface facing portion.   The device includes a stay provided inside the rotating body for maintaining rigidity, and the tilt restricting mechanism includes a first engagement portion provided on the movable member, and a first engagement provided on the stay. The image heating apparatus according to claim 6, further comprising a second engagement portion that engages with the engagement portion.   The apparatus includes a heater holder, and the tilt restriction mechanism includes a first engagement portion provided on the movable member, a second engagement portion provided on the heater holder and engaged with the first engagement portion, The image heating apparatus according to claim 6, further comprising:   The image heating apparatus according to claim 1, wherein the rotating body is not stretched.   A backup unit that is in contact with the inner surface of the rotating body in the direction of the generatrix, and a roller that forms a nip portion that sandwiches and conveys the recording material together with the backup unit via the rotating body. The image heating apparatus according to claim 1, wherein the image heating apparatus rotates following the rotation of the roller.   The image heating apparatus according to claim 1, wherein the apparatus further includes a heater for heating the rotating body. The image heating apparatus according to claim 13, wherein the heater is in contact with an inner surface of the rotating body.

Images