JP2015072421A - Fixing apparatus and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce friction between a belt for fixing an image on a recording material and a heating section which comes into contact with the belt to heat it, in a short time after start of heating.SOLUTION: A heating section 64 includes a metal layer in contact with an inner peripheral surface of a fixing belt 61, and a heat generating section of a stainless wire arranged in a direction which crosses a moving direction of the fixing belt 61. A recess is formed on a surface of the metal layer. The recess is located in a pattern area of the heat generating section when seen from the surface of the metal layer. The inner peripheral surface of the fixing belt 61 is applied with oil. When the heating section and the fixing belt are cool, the oil is accumulated in the recess. When a current flows in the heat generating section and the fixing belt 61 is rotated, a groove is located above the pattern of the heat generating section to quickly transfer heat of the heat generating section to the oil thereby reducing viscosity of the oil. When the fixing belt 61 is moved, the oil spreads to areas other than the groove quickly, thereby reducing friction between the fixing belt 61 and the heating section 64 in a short time.

Description

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

Patent Document 1 discloses a fixing device that fixes a toner image using an endless fixing film. This fixing device rotates a fixing film while heating it with a cylindrical film guide. The toner image on the recording material conveyed between the rotating fixing film and the pressure roller is fixed to the recording material by the heat of the heated fixing film and the pressure by the pressure roller. The surface of the film guide is provided with a plurality of recesses (spherical dimples or grooves), and lubricating oils for reducing sliding resistance with the fixing film are held in the recesses.
Patent Document 2 also discloses a fixing device that fixes a toner image using an endless fixing film. A sliding member that is in close contact with the fixing film is provided on the inner surface side of the portion of the fixing film that faces the pressure roller. The sliding member has a plurality of minute recesses in the moving direction of the fixing film. ing. When the toner image is fixed on the recording material, the recording material is conveyed between the fixing film in contact with the sliding member and the pressure roller. The sliding member has a plurality of minute recesses in the moving direction of the fixing film, and grease is applied to the surface in contact with the fixing film, so that the frictional force between the sliding member and the fixing film is reduced. Lower.

JP 2001-203062 A JP 2003-77621 A

  An object of the present invention is to reduce friction between a belt that fixes an image on a recording material and a heating unit that contacts the belt and heats the belt in a short time after heating is started.

  According to a first aspect of the present invention, there is provided a fixing device comprising: an endless belt whose outer peripheral surface is in contact with a recording material on which an image is formed; a pressure unit that is in contact with the inner peripheral surface of the belt; A rotating body that presses the recording material conveyed between the belt and the belt, a surface layer that is in contact with an inner peripheral surface of the belt, and a back surface side of the surface layer along the surface layer. A heating part having a heating element pattern for heating the surface layer, wherein the pattern is provided in a direction intersecting with a moving direction of the belt, and is recessed in a portion on the surface of the surface layer. And a lubricant applied to the inner peripheral surface of the belt.

  The fixing device according to a second aspect of the present invention is the fixing device according to the first aspect, wherein the concave portion overlaps the region of the pattern when viewed from the front surface side.

  A fixing device according to a third aspect of the present invention is the fixing device according to the first or second aspect, wherein the heating portion has a concave portion outside the region of the pattern when viewed from the surface side.

  According to a fourth aspect of the present invention, in the fixing device according to the third aspect, the depth of the concave portion outside the pattern region when viewed from the front surface side is the region of the pattern when viewed from the front surface side. It has a structure deeper than the depth of the recessed part which overlaps inside.

  A fixing device according to a fifth aspect of the present invention is the fixing device according to any one of the first to fourth aspects, wherein the shape of the surface is an arc shape, and the belt is a circumferential direction of the arc-shaped surface. And the longitudinal direction of the concave portion is configured to intersect the direction orthogonal to the circumferential direction.

  A fixing device according to a sixth aspect of the present invention is the fixing device according to any one of the first to fifth aspects, wherein a plurality of the concave portions are provided on the surface layer, and the belt moves through the plurality of concave portions. When viewed in the direction, it has a configuration in which adjacent recesses are in contact with each other or overlap.

  According to a seventh aspect of the present invention, there is provided an image forming apparatus according to a first aspect of the present invention, wherein an image forming portion that forms an image of an image forming material on a recording material and a recording material on which an image is formed by the image forming portion are conveyed. A fixing device according to any one of Items 6 to 6.

According to the fixing device of the first aspect of the present invention, the friction between the belt that fixes the image on the recording material and the heating unit that heats the belt in contact with the belt can be reduced in a short time from the start of heating. Can be small.
According to the fixing device of the second aspect of the present invention, the lubricant can be heated quickly.
According to the fixing device of the third aspect of the present invention, the abrasion powder of the belt can be retained in the concave portion outside the pattern area when viewed from the front side.
According to the fixing device of the fourth aspect of the present invention, the concave portion outside the pattern region when viewed from the front side is not viewed from the front side as compared with the configuration where the concave portion is not deeper than the concave portion within the pattern region when viewed from the front side. Thus, the belt wear powder can be further retained in the recesses outside the pattern area.
According to the fixing device of the fifth aspect of the present invention, the heating unit is less likely to be damaged as compared with a configuration including a recess having a longitudinal direction in a direction orthogonal to the circumferential direction.
According to the fixing device of the sixth aspect of the present invention, the lubricant can be spread on the inner peripheral surface of the belt without a gap with respect to the moving direction of the belt.
According to the image forming apparatus of the seventh aspect of the present invention, the friction between the belt that fixes the image on the recording material and the heating unit that heats the belt in contact with the belt is reduced in a short time from the start of heating. Can be made smaller.

1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. The perspective view of a fixing unit. Sectional drawing of a fixing unit. The perspective view of a heating part. The figure which looked at the heating part from one side of the longitudinal direction. The top view of a heating part. Sectional drawing of a heating part. The figure which showed the comparative example of this embodiment. The top view of the heating part which concerns on the modification of this invention. Sectional drawing of the heating part which concerns on the modification of this invention. Sectional drawing of the heating part which concerns on the modification of this invention. The top view of the heating part which concerns on the modification of this invention. The top view of the heating part which concerns on the modification of this invention. The top view of the heating part which concerns on the modification of this invention. The top view of the heating part which concerns on the modification of this invention.

[Embodiment]
FIG. 1 is a diagram showing a configuration of an image forming apparatus 1 according to an embodiment of the present invention. The image forming apparatus 1 is an apparatus that forms an image on a recording material by an electrophotographic method. The image forming apparatus 1 according to the present embodiment is a so-called tandem type, and forms an image on a sheet P that is an example of a recording material based on image data representing an image.

  The image forming apparatus 1 includes an image forming unit 10 that forms an image on a sheet P, and a control unit 31 that controls the entire image forming apparatus 1. The image forming apparatus 1 also includes a communication unit 32 that acquires image data by communicating with a computer device or an image reading device (for example, a scanner), and an image processing unit 33 that performs image processing on the acquired image data. ing.

  The image forming unit 10 includes four image forming units 11Y, 11M, 11C, and 11K, which are examples of means for forming a toner image on the paper P. Each of the image forming units 11Y, 11M, 11C, and 11K arranged side by side at a predetermined interval includes a photosensitive drum 12, a charger 13, an exposure device 14, a developing device 15, and a drum cleaner 16. . The photosensitive drum 12 is an example of an image holding body that holds a toner image on which an electrostatic latent image is formed. The charger 13 is a device that charges the surface of the photosensitive drum 12 with a predetermined potential. The exposure device 14 is a device that exposes the photosensitive drum 12 charged by the charger 13 based on image data. The developing device 15 is a device that supplies toner to the photosensitive drum 12 and develops the electrostatic latent image formed on the photosensitive drum 12. The drum cleaner 16 is a device that cleans the surface of the photosensitive drum 12 after the toner image is transferred to the recording material.

  The developing device of the image forming unit 11Y contains yellow (Y) toner, the developing device of the image forming unit 11M contains magenta (M) toner, and the developing device of the image forming unit 11C is cyan (C ), And the developing device of the image forming unit 11K contains toner of key tone (K) (black in this embodiment). The image forming units 11Y, 11M, 11C, and 11K are different in the color of toner stored in the developing unit 15, and the other configurations are the same. For this reason, in the following description, when it is not necessary to distinguish each, it is called the image forming unit 11.

  Further, the image forming unit 10 receives the toner images of the respective colors formed by the intermediate transfer belt 20 onto which the toner images formed on the photosensitive drums 12 of the image forming units 11 are transferred in an overlapping manner and the image forming units 11. A primary transfer roll 21 for transferring (primary transfer) to the intermediate transfer belt 20 is provided. Further, the image forming unit 10 includes a secondary transfer roll 22 that batch-transfers (secondary transfer) toner images of each color transferred and superimposed on the intermediate transfer belt 20 to the paper P, and a toner image of each color that is secondarily transferred. A fixing unit 60 as an example of a fixing unit (fixing device) for fixing the toner image on the paper P is provided. In the image forming apparatus 1 of the present embodiment, the intermediate transfer belt 20, the primary transfer roll 21, and the secondary transfer roll 22 constitute a transfer unit.

In the image forming apparatus 1, each unit is controlled by the control unit 31, and an image forming process on the paper P is performed. Specifically, image data transmitted from another device is received by the communication unit 32. The image processing unit 33 performs predetermined known image processing on the image data received by the communication unit 32 to generate image data of each color of Y, M, C, and K, and converts the image data of each color into each color. To the image forming unit 11 corresponding to
For example, in the image forming unit 11K that forms a black (K) toner image, the photosensitive drum 12 is charged at a predetermined potential by the charger 13 while rotating in the direction of arrow A. In the image forming unit 11K, the exposure device 14 exposes the photosensitive drum 12 based on the image data of the black image sent from the image processing unit 33. As a result, an electrostatic latent image corresponding to a black image is formed on the photosensitive drum 12. The electrostatic latent image formed on the photosensitive drum 12 is developed by the developing device 15, and a black toner image is formed on the photosensitive drum 12. Similarly, yellow (Y), magenta (M), and cyan (C) toner images are formed in the image forming units 11Y, 11M, and 11C, respectively.

  The toner image formed on the photosensitive drum 12 of each image forming unit 11 is transferred (primary transfer) by the primary transfer roll 21 onto the intermediate transfer belt 20 that moves in the direction of arrow B, and the toner images of the respective colors are transferred to the intermediate transfer belt. Overlaid on top. The four color toner images superimposed on the intermediate transfer belt 20 move to a region (secondary transfer portion T) where the secondary transfer roll 22 is disposed as the intermediate transfer belt 20 moves. Further, the paper P is conveyed from the storage unit 40 storing the paper P to the secondary transfer unit T. The toner image on the intermediate transfer belt 20 is transferred (secondary transfer) by the secondary transfer roll 22 onto the paper P conveyed from the storage unit 40. The toner attached to the photosensitive drum 12 after the primary transfer is removed from the photosensitive drum 12 by the drum cleaner 16, and the toner attached to the intermediate transfer belt 20 after the secondary transfer is intermediated by the belt cleaner 25. It is removed from the transfer belt 20.

  The sheet P on which the toner image is transferred is conveyed to the fixing unit 60. The toner image on the paper P conveyed to the fixing unit 60 receives heat and pressure by the fixing unit 60 and is fixed on the paper P.

  Here, details of the fixing unit 60 provided in the image forming apparatus 1 of the present embodiment will be described. 2 is a perspective view of the fixing unit 60, and FIG. 3 is a cross-sectional view of the fixing unit 60 cut in the Y-axis direction of FIG. In FIG. 2, the X axis, the Y axis, and the Z axis that are orthogonal to each other indicate the orthogonal coordinates of the three-dimensional space. The vertical direction is the Z axis, the longitudinal direction of the fixing unit 60 is the X axis, The hand direction is the Y axis. Further, in FIG. 3, in order to prevent the drawing from becoming complicated, characteristic portions in the present embodiment are shown.

  The fixing unit 60 includes a fixing belt 61 that is an example of a belt that fixes a toner image on a sheet P, a pressure roll 62 that is an example of a member that applies pressure to the sheet P, and a fixing belt 61 that faces the pressure roll 62. A pad 63 that is pressed against the inner peripheral surface of the fixing belt 61 and a heating unit 64 that heats the fixing belt 61 are provided. The fixing unit 60 also includes a first support portion 65, a second support portion 66, a peeling member 70, a correction portion 100 that corrects the paper P curled by the fixing unit 60, and a moving mechanism 200 that moves the pressure roll 62. ing.

The fixing belt 61 is an endless belt, and rotates in the direction of arrow C shown in FIG.
The pressure roll 62 is an example of a rotating body that applies pressure to the paper P while rotating, and is disposed so as to face the fixing belt 61 and rotates in the direction of arrow D in FIG. The pressure roll 62 includes, for example, a core 621 in which a metal is formed into a cylindrical shape, and an elastic layer 622 made of an elastic material having heat resistance and elasticity such as silicone sponge coated on the outer peripheral surface of the core 621. Note that a release layer which is a heat-resistant film such as a fluororesin containing carbon or a heat-resistant rubber film is laminated on the surface of the core 621.

  The first support part 65 is formed by bending a metal plate and supports the heating part 64. The second support portion 66 is formed by bending a metal plate and supports the pad 63. In addition, the 2nd support part 66 also supports the 1st support part 65 via the spring 67 which is an example of the elastic member which has elasticity. The first support part 65 and the second support part 66 have a longitudinal direction in the axial direction of the pressure roll 62.

  The pad 63 is made of an elastic material such as elastic silicone rubber or fluorine rubber, or a heat-resistant material such as PPS (Poly Phenylene Sulfide) resin or LCP (Liquid Crystal Polymer) resin. The pad 63 is an example of a member (pressure unit) that applies pressure to the paper P, and is supported by the second support unit 66 so as to face the pressure roll 62. The pad 63 also has a longitudinal direction in the axial direction of the pressure roll 62.

  The heating unit 64 is an example of a member that heats the fixing belt 61. 4 is a perspective view of the heating unit 64, and FIG. 5 is a diagram of the heating unit 64 as viewed from one side in the longitudinal direction (the positive side of the X axis in FIG. 4). FIG. 6 is a top view of the heating unit 64 that is removed from the first support unit 65 and is in a flat plate state, and FIG. 7 is a cross-sectional view of the heating unit 64 cut along the longitudinal direction. The heating part 64 is bent in an arc shape as shown in the figure, and both ends in the lateral direction are fixed to the first support part 65. The heating unit 64 according to this embodiment includes a metal layer 641, a protective layer 642, and a heat generating unit 643.

  The heat generating portion 643 is a stainless steel wire in the present embodiment. The heat generating portion 643 is an example of a heat generating body that generates heat. The heat generating portion 643 may be another metal wire as long as it generates heat. The heat generating unit 643 is connected to a power source (not shown), and generates heat when a current flows from the power source. The heat generating portion 643 is covered with the protective layer 642 and located on the lower surface side of the metal layer 641. In the present embodiment, the heat generating unit 643 is provided in a direction (longitudinal direction of the heating unit 64) that intersects the direction of the arrow C that is the moving direction of the fixing belt 61. Further, in the present embodiment, as shown in FIG. 6, the heat generating portion 643 has a pattern obtained by bending a plurality of straight lines, and a portion (first portion 643 a) along the longitudinal direction of the heating portion 64. And a portion (second portion 643b) having an angle with respect to the arrow C direction from one side in the short direction of the heating unit 64 to the other side. The protective layer 642 is a polyimide resin in this embodiment. As shown in FIG. 7, the protective layer 642 is provided on the lower surface side of the metal layer 641 and covers and protects the heat generating portion 643. Note that the protective layer 642 is not limited to polyimide resin, and other resins may be used for heat resistance.

  In the present embodiment, the metal layer 641 is a stainless steel layer having a thickness of 20 μm to 100 μm. The metal layer 641 is an example of a surface layer of the heating unit 64. The surface of the metal layer 641 opposite to the protective layer 642, that is, the outer surface when the heating unit 64 has an arc shape, contacts the fixing belt 61 and supports the fixing belt 61. A lubricant (for example, oil) for reducing the frictional force between the metal layer 641 and the fixing belt 61 is applied to the surface of the metal layer 641 and the inner peripheral surface of the fixing belt 61. The lubricant is not limited to oil and may be other lubricants such as grease.

Also, a plurality of grooves 641a are provided on the surface of the metal layer 641 as shown in FIGS. The groove 641 a is an example of a recess provided in the surface layer of the heating unit 64. The fixing belt 61 is in contact with a region between the groove 641a at one end in the longitudinal direction of the heating unit 64 and the groove 641a at the other end. The groove 641a is provided so as to be located in the region of the second portion 643b when the metal layer 641 is viewed from the surface side as shown in FIG. Further, the longitudinal direction of the groove 641a intersects the direction perpendicular to the circumferential direction of the arc-shaped metal layer 641, that is, the longitudinal direction of the heating section 64 as shown in FIG. Is taken, the direction intersects the X axis.
As shown in FIG. 6, when the X axis is taken in the longitudinal direction of the heating unit 64, when two adjacent grooves 641 a are viewed, the groove 641 a on the negative direction side of the X axis is on the positive side of the X axis. The position of the end (position A1) is the same as the position of the end (position A2) on the negative side of the X axis in the groove 641a on the positive direction side of the X axis in the X axis direction. In other words, when the plurality of grooves 641a are viewed from the upstream side in the moving direction of the fixing belt 61, the adjacent grooves 641a are in contact with each other.

  In the present embodiment, since the groove 641a is provided on the surface of the heating unit 64, that is, the surface of the metal layer 641 in contact with the fixing belt 61 in this manner, the state before the fixing belt 61 is heated is cooled. The lubricant in the state is accumulated in the groove 641a. When a current is passed through the heat generating portion 643 while the fixing belt 61 and the lubricant are cold, heat generated in the heat generating portion 643 is transmitted from the protective layer 642 to the metal layer 641. Here, since the groove 641a in which the lubricant is accumulated is on the pattern of the heat generating portion 643, the heat generated in the heat generating portion 643 is quickly transmitted to the lubricant as compared with the configuration in which the metal layer 641 does not have the groove 641a. When the viscosity of the lubricant decreases and the fixing belt 61 is moved, the lubricant spreads quickly to the region other than the groove 641a.

  In this embodiment, when the plurality of grooves 641a are viewed from the upstream side in the moving direction of the fixing belt 61, the adjacent grooves 641a are in contact with each other. Here, for comparison, for example, as shown in FIG. 8, when the plurality of grooves 641 a are viewed from the upstream side in the moving direction of the fixing belt 61, adjacent grooves 641 a are separated from each other and there is a gap AP. Is assumed. In this case, since the moving direction of the fixing belt 61 in contact with the metal layer 641 is the direction of the arrow C in the drawing, the heated lubricant moves from the groove 641a to the region on the arrow C direction side as the fixing belt 61 moves. It spreads and it becomes slow that a lubricant spreads in the part of crevice AP. That is, the portion of the fixing belt 61 that contacts the gap AP has a greater frictional force than the portion of the fixing belt 61 that moves on the groove 641a. On the other hand, in this embodiment, since there is no gap AP, a portion where the frictional force is increased on the inner peripheral surface of the fixing belt 61 is less likely to occur.

  Returning to FIG. 3, the moving mechanism 200 is a mechanism for moving the pressure roll 62. The moving mechanism 200 moves the pressure roll 62 toward the pad 63 when fixing the toner image on the paper P. By pressing the fixing belt 61 against the pad 63 with the pressure roll 62 and sandwiching the fixing belt 61 between the pressure roll 62 and the pad 63, a nip portion N where the fixing belt 61 and the pressure roll 62 contact is formed. When the sheet P holding the unfixed toner image passes through the nip portion N, the sheet P is heated by the fixing belt 61 heated by the heating unit 64, and the sheet P is heated by the pressure roll 62 and the pad 63. The toner image is fixed on the paper P by being pressurized. The moving mechanism 200 moves the pressure roll 62 so that the pressure roll 62 is separated from the fixing belt 61 except when fixing the toner image on the paper P.

  The peeling member 70 is a member for peeling the paper P from the fixing belt 61, and is disposed on the downstream side in the transport direction of the paper P when viewed from the nip portion N. The correction unit 100 includes a rotating shaft 111 that is rotated by a motor (not shown), and a roll 110 that rotates integrally with the rotating shaft 111. In addition, the correction unit 100 includes a roll 120 that is pressed against the roll 110 and rotates, and a guide member 130 to which the rotation shaft 111 is attached. The guide member 130 is a member that guides the paper P that has passed through the nip portion N between the roll 110 and the roll 120, and is disposed on the downstream side in the transport direction of the paper P as viewed from the nip portion N. The rotating shaft 111 is rotated in the direction of arrow F by a motor (not shown). The roll 120 is pressed against the roll 110 by a spring (not shown), and rotates in the direction of arrow G in accordance with the rotation of the roll 110.

  The paper P on which the toner image has been fixed by passing through the nip portion N passes between the roll 110 and the roll 120. The roll 120 is, for example, a stainless steel roll, and the roll 110 has a surface made of resin, rubber, or the like. That is, the roll 120 has a configuration that is harder than the roll 110. The sheet P that has passed through the nip portion N of the fixing unit 60 is curled to the fixing belt 61 side. However, in the correction unit 100, since the roll 120 is harder than the roll 110, the paper P receives a force in a direction of curling to the opposite side of the fixing belt 61 between the roll 120 and the roll 110, and the paper P The curl is removed. The paper P that has passed between the roll 110 and the roll 120 is conveyed outside the image forming apparatus 1 and stacked on the stacking unit 45.

[Modification]
As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above, It can implement with another various form. For example, the present invention may be implemented by modifying the above-described embodiment as follows. In addition, you may combine each of embodiment mentioned above and the following modifications.

  The image forming apparatus including the fixing unit 60 is not limited to the tandem type of the above-described embodiment, and may be another configuration such as a rotary type. The image forming apparatus including the fixing unit 60 is not limited to an image forming apparatus that forms an image by superimposing a plurality of color toner images, but is an image forming apparatus that forms a single color toner image. May be.

  In the present invention, the configuration of the groove 641a is not limited to the configuration of the above-described embodiment, and may be another configuration. For example, as shown in FIG. 9, a configuration in which a part of the adjacent groove 641a is located in a region on the downstream side in the moving direction of the fixing belt 61 as viewed from the groove 641a on the negative direction side of the X axis, that is, the fixing belt. When the plurality of grooves 641a are viewed from the upstream side in the moving direction 61, the adjacent grooves 641a may be seen to overlap each other.

In the above-described embodiment, the groove 641a is configured to be located in the region of the second portion 643b when the metal layer 641 is viewed from the surface side. However, the width of the groove 641a in the X-axis direction is May be wider than the width of the second portion 643b.
In the above-described embodiment, the groove 641a is configured to be located in the region of the second portion 643b when the metal layer 641 is viewed from the surface side. However, the groove 641a is also formed in the first portion 643a. You may make it provide.
In the present invention, as shown in FIG. 10, the metal layer 641 may be provided with a groove 641b on the protective layer 642 side.

  In the embodiment described above, the heating unit 64 includes the metal layer 641, but is not limited to this configuration. For example, as illustrated in FIG. 11, the heating unit 64 may be configured to include the groove 642 a in the protective layer 642 without including the metal layer 641. In this case, the protective layer 642 becomes the surface layer of the heating unit 64.

  In the above-described embodiment, the groove 641a is provided so as to be positioned in the region of the second portion 643b when the metal layer 641 is viewed from the surface side, but is not limited to this configuration. For example, as shown in FIG. 12, a groove 641b may be provided in a portion where the first portion 643a and the second portion 643b are not provided. Note that the depth of the groove 641b may be deeper than the depth of the groove 641a. According to this configuration, the abrasion powder of the fixing belt 61 worn by friction with the heating unit 64 and the pad 63 remains in the groove 641b.

In the above-described embodiment, the heat generating portion 643 has a pattern obtained by bending a plurality of straight lines, but is not limited to this configuration. For example, the heat generating portion 643 may be a pattern in which straight lines and curves are connected as shown in FIG.
Further, as shown in FIG. 14, the heat generating portion 643 is configured to have one linear portion that is inclined from one side in the short direction of the heating portion 64 to the other side, and the groove 641 a extends along the heat generating portion 643. It is good also as a structure of one diagonal straight line.
Further, the heat generating portion 643 may have a single straight portion along the longitudinal direction of the heating portion 64, and the groove 641 a may also have a straight configuration along the longitudinal direction of the heating portion 64 along the heat generating portion 643. .
Moreover, although the heat generating portion 643 has a continuous pattern configuration in the above-described embodiment, it is not limited to this configuration. For example, as illustrated in FIG. 15, the heating unit 64 may include a plurality of heat generating units 643, and a groove 641 a may be provided along each heat generating unit 643.

  In the embodiment described above, the shape of the cross section of the groove 641a is rectangular, but it is not limited to this configuration. The cross-sectional shape of the groove 641a may be another shape such as a valley shape or an arc shape.

  In the above-described embodiment, the pad 63 is opposed to the pressure roll 62 with the fixing belt 61 interposed therebetween, but the member facing the pressure roll 62 with the fixing belt 61 interposed therebetween is limited to the pad 63. It is not something. For example, instead of the pad 63, a rotating roll (an example of a pressure unit that contacts the inner peripheral surface of the fixing belt 61 and applies pressure to the paper P) is disposed. The nip portion N may be formed by being sandwiched.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 10 ... Image forming part, 31 ... Control part, 60 ... Fixing unit, 61 ... Fixing belt, 62 ... Pressure roll, 63 ... Pad, 64 ... Heating part, 65 ... 1st support part, 66 ... 2nd support part, 70 ... Peeling member, 100 ... Correction part, 200 ... Movement mechanism, 641 ... Metal layer, 641a ... Groove, 642 ... Protective layer, 643 ... Heat generating part

Claims (7)

An endless belt whose outer peripheral surface is in contact with the recording material on which the image is formed;
A pressurizing part in contact with the inner peripheral surface of the belt;
A rotating body that opposes the pressure unit across the belt and pressurizes the recording material conveyed between the belt;
A heating part having a surface layer whose surface is in contact with the inner peripheral surface of the belt, and a heating element pattern that is provided on the back surface side of the surface layer along the surface layer to heat the surface layer, the pattern being the belt A heating unit that is provided in a direction crossing the moving direction of the surface layer and has a recess in a portion on the pattern on the surface of the surface layer;
And a lubricant applied to the inner peripheral surface of the belt.   The fixing device according to claim 1, wherein the concave portion overlaps an area of the pattern when viewed from the front surface side.   The fixing device according to claim 1, wherein the heating unit has a concave portion outside the region of the pattern when viewed from the surface side.   4. The fixing device according to claim 3, wherein a depth of the concave portion outside the region of the pattern when viewed from the front surface side is deeper than a depth of the concave portion overlapping with the region of the pattern when viewed from the front surface side. The shape of the surface is arcuate,
The belt rotates in the circumferential direction of the arcuate surface and contacts the surface;
The fixing device according to any one of claims 1 to 4, wherein a longitudinal direction of the concave portion is a direction intersecting with a direction orthogonal to the circumferential direction. A plurality of the recesses are provided on the surface layer,
6. The fixing device according to claim 1, wherein when the plurality of concave portions are viewed in the moving direction of the belt, adjacent concave portions are in contact with or overlap each other. An image forming unit for forming an image of the image forming material on a recording material;
The fixing device according to any one of claims 1 to 6, wherein a recording material on which an image is formed by the image forming unit is conveyed.
An image forming apparatus comprising:

Images