JP2015041005A - Fixing apparatus and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing apparatus having a sliding member for reducing friction between a member forming a nip part and a belt member when the belt member is rotated, while improving durability of the sliding member as well as the belt member.SOLUTION: A fixing apparatus for fixing a toner image on a recording medium P includes: a pressure member 7 arranged rotatably; a sleeve-like flexible belt member 8 which is rotated in contact with the pressure member 7; a nip-part forming member 5 which is arranged on the side of an inner periphery of the belt member 8 to form a nip part N when the pressure member 7 comes into contact with an outer peripheral surface of the belt member 8; a stay member 2 for supporting the nip-part forming member 5 against pressure when pressed by the pressure member 7; and a sliding member 4 for covering an outer peripheral surface including a surface in contact with a belt member inner peripheral surface of the nip-part forming member 5. The sliding member 4 is an endless sheet arranged to be rotatable on the outer peripheral surface of the nip-part forming member 5.

Description

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

In an image forming apparatus using an electrophotographic method such as a copying machine, a printer, a facsimile, or a multifunction machine having these functions, a belt type fixing device is used as a device for fixing a toner image on a recording medium (paper). It has been.
As a belt type fixing device, for example, a rotatable belt member heated by a heat source, a pressure roller rotating in pressure contact with the belt member, and a belt member and a pressure roller disposed inside the belt member And a member for forming a nip portion (nip forming member) between the sheet and the sheet, and a sheet is passed through the nip portion to fix the unfixed toner image by heat and pressure.

  In such a belt-type fixing device, if friction between the belt member and a member that applies pressure to the belt member (for example, a nip forming member) is large, the inside of the belt member or a sliding portion of the nip forming member There is a problem that the wear of the parts becomes severe and the service life of the parts is remarkably shortened.

  Therefore, the sliding resistance of the nip forming member with respect to the inner side of the belt member is required to be small, and the sliding resistance is reduced by providing a low-friction sliding member or a mechanism for applying a lubricant. (Patent Documents 1 to 3).

  In Patent Document 1, in order to stabilize the slidability of the endless belt in the fixing device, a rotatable fixing roll, an endless belt movable while contacting the fixing roll, and an inner side of the endless belt are arranged. , A pressure pad that forms a nip portion through which paper passes between the fixing roll and the endless belt, and a lubricant that is formed of a porous material and applies a lubricant to the endless belt in contact with the inner peripheral surface of the endless belt A fixing device including a supply member and a peeling nip member as a pressure application member is disclosed. With such a configuration, the lubricant that exudes to the surface by capillary action from the inside of the porous body when the endless belt rotates is applied to the inner peripheral surface of the endless belt, and friction of the sliding portion can be reduced. Further, it is described that a low friction sheet is provided on the surface in contact with the endless belt in order to reduce the sliding resistance between the inner peripheral surface of the endless belt and the pre-nip member.

  In Patent Document 2, when the belt slides on the low-friction sheet in a state where the belt and the low-friction sheet are sandwiched between the nip forming member and the pressure roller with a relatively strong force, the rubbing is performed. In order to enable the low friction sheet to be supported in an appropriate state even if the low friction sheet receives a pulling force in the belt traveling direction due to resistance, the endless belt having flexibility and the inner peripheral surface side of the endless belt When the pressure roller contacts the outer peripheral surface of the belt, the nip forming member, the opposing member fixed on the inner peripheral surface side of the belt at a position excluding the nip portion, and the opposing member are heated. Heating means, a reinforcing member that supports the nip forming member from behind when the pressure roller presses the belt and the nip forming member, and a rotation of the pressure roller disposed between the belt and the nip forming member. Sliding when the belt runs And a low-friction sheet for lowering the resistance, the low friction sheet, a fixing device is disclosed in which a sheet fixing means for fixing in the direction of the sides throughout perpendicular to the belt running direction. By providing the sheet fixing means, it is possible to reduce the size and cost of the apparatus, and to prevent the low friction sheet from shifting even when the nip width is increased or the applied pressure is increased. be able to.

In Patent Document 3, a temporal change is made between the outer peripheral surface of a pressing member that presses the rotating member against the other rotating member from the inside of one of two rotating members that form a fixing nip, and the inner peripheral surface of the rotating member. In order to improve the durability of the pressing member and the rotating member while preventing a situation in which the sliding resistance increases, at least one of the rotating members provided with a heating member and in contact with each other, and one of these rotating members A pressing member that presses the rotating member against the other rotating member, and a low-friction rubbing member that is disposed on the outer peripheral surface of the pressing member. A fixing device is disclosed in which the film strength of the innermost layer located on the inner peripheral surface of the rotating member on which the pressing member is arranged is set to be larger than the surface strength of the rubbing member.
An embodiment (FIGS. 2 and 4) in which the cross-sectional shape of the pressing member is a circular or polygonal member and an embodiment (FIG. 6) in which the pressing member is an endless belt-like member are disclosed. It is described that both the pressing member and the rubbing member are rotationally moved by being covered with the rubbing member.

  In the fixing device of Patent Document 1, the friction between the endless belt and the sliding portion can be reduced by applying a lubricant, but the low friction sheet provided on the surface in contact with the endless belt receives sliding resistance. When the sheet is damaged by a sliding load, there is a problem that the unit needs to be replaced.

  Further, in the fixing device disclosed in Patent Document 2, although the friction between the belt member and the sliding portion can be reduced by using the low friction sheet, the low friction sheet whose entire side direction is fixed by the leaf spring rotates. It may be damaged by a sliding load with the belt member, and when the fixing is released due to the set state of the leaf spring or the like, the low friction sheet may be displaced and damaged. For this reason, there exists a problem that unit replacement | exchange accompanying the failure | damage of a low friction sheet | seat is needed.

  On the other hand, in the fixing device of Patent Document 3, the durability of the sliding member can be improved by rotating the sliding member together with the pressing member. Uneven rotation of the fixing belt may be caused, which may adversely affect paper passing to the nip portion. Therefore, if the sliding member is rotated when the paper is not passed through the nip portion or when the fixing belt is not rotated, a satisfactory improvement in durability during paper feeding cannot be obtained. There is.

  In view of the above problems, the present invention includes a sliding member that can reduce friction caused by rotation of the belt member between the member forming the nip portion and the belt member, and the durability of the sliding member itself together with the belt member. It is an object of the present invention to provide a fixing device having excellent properties.

  In order to solve the above-described problems, a fixing device according to the present invention is a fixing device that fixes a toner image on a recording medium, and is configured to contact a pressure member disposed rotatably and the pressure member. A flexible sleeve-shaped belt member that rotates, and a nip portion forming member that is disposed on the inner peripheral side of the belt member and forms a nip portion when the pressure roller contacts the outer peripheral surface of the belt member A stay member that supports the nip portion forming member against the pressing force when the belt member and the nip portion forming member are pressed against the pressure roller, and the belt member of the nip portion forming member. A sliding member that covers an outer peripheral surface including a surface that contacts the inner peripheral surface of the nip portion, and the sliding member is an endless sheet that is rotatably disposed on the outer peripheral surface of the nip portion forming member. A fixing device characterized by being It is.

  According to the fixing device of the present invention, the sliding member capable of reducing friction caused by the rotation of the belt member between the member forming the nip portion and the belt member is provided, and the durability of the sliding member itself together with the belt member is provided. In addition, an excellent fixing device can be provided.

FIG. 3 is a perspective view illustrating an example of a configuration of a main part of a fixing device according to the present invention. 2 is a cross-sectional view illustrating an example of a configuration of a fixing device according to the present invention. FIG. FIG. 3 is a side view illustrating an example of a main configuration of a fixing device according to the present invention. 1 is an overall configuration diagram illustrating an example of an image forming apparatus according to the present invention.

  Hereinafter, a fixing device and an image forming apparatus according to the present invention will be described with reference to the drawings. It should be noted that the present invention is not limited to the embodiments of the examples shown below, and other embodiments, additions, modifications, deletions, and the like can be changed within a range that can be conceived by those skilled in the art. Any aspect is included in the scope of the present invention as long as the operations and effects of the present invention are exhibited.

[Fixing device]
FIG. 1 is a perspective view of a main part of the fixing device of the present embodiment, showing a state in which a belt member that is a fixing member is removed. FIG. 2 is a cross-sectional view of the fixing device of the present embodiment, and FIG. 3 is a side view of the main part of the fixing device of the present embodiment.

  As shown in FIG. 2, the fixing device of the present embodiment is a fixing device that fixes a toner image on a recording medium P, and includes a pressure member (pressure roller) 7 that is rotatably arranged, and a pressure. A flexible belt-shaped belt member 8 that rotates while contacting the member 7, a heating unit 9 that heats the belt member 8, and an inner peripheral side of the belt member 8, and the pressure member 7 is the belt member The nip portion forming member (base pad) 5 that forms the nip portion N when contacting the outer peripheral surface 8, the belt member 8, and the nip portion forming member 5 are pressed against the pressing member 7. A sliding member (sliding) covering an outer peripheral surface including a stay member (pressure stay) 2 that supports the nip portion forming member 5 against the surface and an abutting surface of the belt member 8 of the nip portion forming member 5. Sheet) 4. The sliding member 4 is an endless sheet that is rotatably disposed on the outer peripheral surface of the nip portion forming member 5.

The stay member 2, the nip portion forming member 5 and the sliding member 4 constitute a pressure applying member.
In the conventional fixing device, the sliding member disposed for the purpose of reducing the sliding resistance inside the belt member 8 is generally fixed to the pressure applying member and does not move. On the other hand, in the fixing device of the present invention, the sliding member 4 is an endless (cylindrical) sheet member and is wound so as to cover the outer peripheral surface of the pressure application member, but is not fixed. It is movable.
The sliding member 4 can reduce sliding friction with the belt member 8 by rotating in the same direction as the belt member 8 following or independently of the rotation of the belt member 8. As a result, the sliding member 4 and the belt member 8 can be prevented from being damaged due to friction or the like, and the effect of improving the durability can be obtained.

  On the other hand, a rubbing member that rotates with the pressing member is also disclosed (FIG. 6 of Patent Document 3). However, rotation of the pressing member itself causes fluctuations in the nip width and uneven rotation of the fixing belt. There's a problem. On the other hand, the pressing member of the fixing device of the present embodiment is composed of two members, the stay member 2 and the nip portion forming member 5, and the sliding member 4 is provided so as to cover only the nip portion forming member 5. It has been. Further, since the nip portion forming member 5 does not rotate, even when the recording medium P is passed through the nip portion N, only the sliding member 4 can be rotated, and the fluctuation of the nip width and the fixing belt can be changed. Reduction in sliding resistance can be realized without causing uneven rotation.

  As shown in FIGS. 1 and 2, a pair of driving rollers 11 for assisting the rotation of the sliding member 4 is provided on the inner peripheral surface side of the sliding member 4 so as to abut on the inner peripheral surface. .

As shown in FIG. 1, the driving roller 11 can be connected to a driving source (not shown) via a driving shaft 12.
By connecting the driving roller 11 to the driving source, the sliding member 4 can be rotated by the power from the driving source. That is, not only the rotational movement following the rotation of the belt member 8, but also the sliding member 4 can be independently rotated. Thereby, the contact area | region with the belt member 8 inner peripheral surface of the sliding member 4 can be updated suitably.

In order to reduce the load when the sliding member 4 rotates, an elastic body 6 is provided between the stay member 2 and the nip portion forming member 5 as shown in FIGS. Accordingly, the stay member 2 and the nip portion forming member 5 can be separated from each other.
As shown in FIG. 3, the elastic body 6 is provided at both ends in the longitudinal direction where the nip portion forming member 5 is not covered with the sliding member 4 in the region where the stay member 2 a and the nip portion forming member 5 face each other. be able to.
Examples of the elastic body 6 include a metal spring.
By forming a gap between the stay member 2 and the nip forming member 5 by the elastic body 6, the sliding member 4 can rotate with a small frictional resistance without coming into contact with the stay member 2.

  Note that the sliding member 4 preferably rotates when the pressure member 7 is depressurized away from the belt member 8. When the pressure member 7 is pressing the belt member 8, the nip pressure is high and the sliding member 4 is difficult to rotate. By rotating the sliding member 4 when the pressure is low, The durability can be further improved.

Furthermore, a lubricant can be applied to reduce the load caused by friction during rotation of the sliding member 4. By rotating the sliding member 4 in a state impregnated with the lubricant, the lubricant can be supplied to the belt member 8 to reduce the sliding resistance.
Further, in order to prevent the sliding resistance from increasing due to the depletion of the lubricant, the lubricant supply means 10 is provided, and the lubricant is supplied when the sliding member 4 comes into contact, thereby further sliding resistance. Reduction and improved durability.
For example, as shown in FIGS. 2 and 3, the lubricant supply means 10 is disposed on the surface of the stay member 2 that faces the nip portion forming member 5 so as to be in contact with the sliding member 4.

  The lubricant is preferably a liquid that can be impregnated in the sliding member 4 and has high heat resistance, and includes, for example, silicone oil.

  The material of the lubricant supply means 10 is preferably a material that is excellent in processability, can be manufactured at low cost, and can be impregnated with a large amount of lubricant, such as a nonwoven fabric (felt).

  As the material of the sliding member 4, a material having a small friction coefficient and excellent wear resistance and heat resistance is preferable, and a material excellent in the above-described lubricant impregnation property is more preferable. For example, the porous resin fiber cloth which consists of a fluororesin is mentioned. Moreover, in order to improve abrasion resistance and heat resistance, what mixed the polyethylene terephthalate (PET) fiber and the polyphenylene sulfide (PPS) fiber can be used.

The operation of the fixing device will be described.
When the power switch of the image forming apparatus main body including the fixing device is turned on, electric power is supplied to the heating means (halogen heater) 9 and rotation of the pressure member 7 is started. Thereby, the belt member 8 is also driven and rotated by the frictional force with the pressure member 7. The recording medium P to which the toner image has been transferred is conveyed in the direction of the arrow in FIG. 2, sent to the nip portion N in a pressure contact state, heated by the belt member 8 heated by the heating means 9, and supported by the stay member 2. The toner image is fixed on the surface of the recording medium P by the pressing force of the nip portion forming member 5 and the pressure member 7.

  By using a metal sleeve having a thin wall and a low heat capacity as the belt member 8, it is possible to greatly shorten the time (warm-up time) for raising the temperature from the room temperature to the fixable temperature when the apparatus is activated. The rotation track of the belt member 8 is corrected by the belt holding member 3 fastened to the side plate 1, but the belt member 8 is interposed between the outer flange 3 a and the inner flange 3 b constituting the belt holding member 3 and the belt member 8. Excessive friction that dulls the rotation of 8 does not occur.

  The heating means 9 is fixed to the side plate 1. The output control of the heating means 9 is performed based on, for example, the surface temperature of the belt member 8 detected by a temperature sensor (not shown). By such output control, the fixing temperature by the belt member 8 can be set to a desired temperature.

  The stay member 2 reinforces and supports the nip portion forming member 5 and is disposed on the inner peripheral surface side of the belt member 8 and is composed of members 2a and 2b as shown in FIG. Both end portions in the width direction of the member indicated by reference numeral 2a are fixedly supported on the side plate 1 as shown in FIG.

Since the stay member 2 supports the nip portion forming member 5 against the pressing force of the pressure member, deformation of the nip portion forming member 5 is suppressed.
The stay member 2 is preferably formed of a metal material having high mechanical strength such as stainless steel or iron. In addition, a heat insulating member can be provided on a part or all of the surface of the stay member 2 facing the heating means 9, or BA treatment or mirror polishing treatment can be performed.

  When the pressure member 7 that contacts the outer peripheral surface of the belt member 8 at the position of the nip portion N is a pressure roller as shown in FIG. 2, the configuration of the pressure roller is, for example, on a hollow cored bar And an elastic layer formed thereon. Examples of the material for the elastic layer include foamable silicone rubber, silicone rubber, fluororubber, and the like, and a thin release layer made of PFA, PTFE, or the like can be provided on the surface layer. When the elastic layer is formed of a sponge-like material such as foamable silicone rubber, the pressure applied to the nip portion N can be reduced, so that the bending that occurs in the nip portion forming member 5 can be reduced. . Furthermore, the heat insulation of the pressure member 7 is enhanced, and the heat of the belt member 8 is less likely to move to the pressure member 7 side, so that the heating efficiency of the belt member 8 is improved. A heating means may be provided inside the pressure member 7.

  As described above, the sliding member 4 is rotated by the rotation of the belt member 8 or independently. In the latter case, the sliding member 4 is driven by the driving roller 11 and rotated. It rotates by the motive power from the drive source which is connected via the drive shaft 12 (not shown).

The fixing device according to the present embodiment includes a control unit that controls the rotation of the sliding member 4, and can rotate the sliding member 4 with the passage of a predetermined rotation time by the control unit.
The predetermined rotation time can be calculated and set based on, for example, a value obtained by integrating the number of sheets passing through the nip portion N, the rotation number of the belt member 8, and the rotation time.

  In this way, the sliding member 4 is rotated when a predetermined rotation time has elapsed, and the new area of the surface is moved to a position where it slides on the belt member 8, thereby further improving the durability of the sliding member 4. It can be improved and a good friction reducing effect can be obtained. The rotation of the sliding member 4 may be intermittent or continuous.

As described above, according to the fixing device of the present invention, the sliding member 4 that contacts the inner side of the rotating belt member 8 rotates following the same direction as the rotation of the belt member 8 to reduce sliding friction. Therefore, damage is suppressed and durability is improved.
Moreover, since the sliding member 4 which is an endless sheet | seat rotates and the whole peripheral surface can be used, it is long life rather than what comprises only one surface.
Further, the sliding member 4 is supplied with a lubricant and is rotated by impregnating the lubricant, thereby preventing an increase in sliding resistance and durability of the fixing unit by preventing the sliding member and the belt member 8 from being damaged. Improvements can be realized.

  In the above-described fixing device, the aspect in which the pressure member is a roller has been described. However, the present invention can also be applied to a configuration in which the pressure member is an endless belt.

[Image forming apparatus]
FIG. 4 is an overall configuration diagram showing an example of an image forming apparatus according to the present invention, and shows the configuration of a tandem type color printer.
As shown in FIG. 4, in the bottle container 101 above the main body of the image forming apparatus of the present embodiment, four toner bottles 102Y, 102M, 102C, and 102K corresponding to the respective colors (yellow, magenta, cyan, and black) are stored. Is installed detachably (changeable).
An intermediate transfer unit 85 is disposed below the bottle housing portion 101. Image forming portions 14Y, 14M, 14C, and 14K corresponding to the respective colors (yellow, magenta, cyan, and black) are arranged in parallel so as to face the intermediate transfer belt 78 of the intermediate transfer unit 85.

  Photosensitive drums 15Y, 15M, 15C, and 15K are disposed in the image forming units 14Y, 14M, 14C, and 14K, respectively. Further, around each of the photosensitive drums 15Y, 15M, 15C, and 15K, a charging unit 75, a developing unit 76, a cleaning unit 77, a charge eliminating unit (not shown), and the like are disposed. Then, an image forming process (charging process, exposure process, development process, transfer process, cleaning process) is performed on each photoconductor drum 15Y, 15M, 15C, 15K, and each photoconductor drum 15Y, 15M, 15C, An image of each color is formed on 15K.

The photosensitive drums 15Y, 15M, 15C, and 15K are rotationally driven in a clockwise direction in FIG. 4 by a drive motor (not shown). Then, the surfaces of the photosensitive drums 15Y, 15M, 15C, and 15K are uniformly charged at the position of the charging unit 75 (this is a charging process).
Thereafter, the surfaces of the photosensitive drums 15Y, 15M, 15C, and 15K reach the irradiation position of the laser light L emitted from the exposure unit 13, and electrostatic latent images corresponding to the respective colors are formed by exposure scanning at this position. (It is an exposure process.)

Thereafter, the surfaces of the photoconductive drums 15Y, 15M, 15C, and 15K reach a position facing the developing unit (developing device) 76, and the electrostatic latent image is developed at this position to form toner images of respective colors. (This is a development process.)
Thereafter, the surfaces of the photoconductor drums 15Y, 15M, 15C, and 15K reach positions facing the intermediate transfer belt 78 and the first transfer bias rollers 79Y, 79M, 79C, and 79K, and the photoconductor drums 15Y, 15M are located at this position. , 15C and 15K are transferred onto the intermediate transfer belt 78 (this is the primary transfer process). At this time, a small amount of untransferred toner remains on the photosensitive drums 15Y, 15M, 15C, and 15K.

Thereafter, the surfaces of the photoconductor drums 15Y, 15M, 15C, and 15K reach a position facing the cleaning unit 77, and untransferred toner remaining on the photoconductor drums 15Y, 15M, 15C, and 15K is removed at this position. 77 is mechanically collected by a cleaning blade (cleaning process).
Finally, the surfaces of the photoconductor drums 15Y, 15M, 15C, and 15K reach a position facing a neutralization unit (not shown), and the residual potential on the photoconductor drums 15Y, 15M, 15C, and 15K is removed at this position. The
Thus, a series of image forming processes performed on the photosensitive drums 15Y, 15M, 15C, and 15K is completed.

Thereafter, the toner images of the respective colors formed on the respective photosensitive drums through the developing process are transferred onto the intermediate transfer belt 78 in an overlapping manner. In this way, a color image is formed on the intermediate transfer belt 78.
Here, the intermediate transfer unit 85 includes an intermediate transfer belt 78, four primary transfer bias rollers 79Y, 79M, 79C, and 79K, a secondary transfer backup roller 82, a cleaning backup roller 83, a tension roller 84, and an intermediate transfer cleaning unit 80. , Etc. The intermediate transfer belt 78 is stretched and supported by the three rollers 82 to 84, and is moved endlessly in the direction of the arrow in FIG.

The four primary transfer bias rollers 79Y, 79M, 79C, and 79K respectively sandwich the intermediate transfer belt 78 with the photosensitive drums 15Y, 15M, 15C, and 15K to form primary transfer nips. Then, a transfer bias reverse to the polarity of the toner is applied to the primary transfer bias rollers 79Y, 79M, 79C, and 79K.
The intermediate transfer belt 78 travels in the direction of the arrow and sequentially passes through the primary transfer nips of the primary transfer bias rollers 79Y, 79M, 79C, and 79K. In this way, the toner images of the respective colors on the photosensitive drums 15Y, 15M, 15C, and 15K are primarily transferred while being superimposed on the intermediate transfer belt 78.

Thereafter, the intermediate transfer belt 78 onto which the toner images of the respective colors are transferred in an overlapping manner reaches a position facing the secondary transfer roller 89. At this position, the secondary transfer backup roller 82 sandwiches the intermediate transfer belt 78 between the secondary transfer roller 89 and forms a secondary transfer nip. The four color toner images formed on the intermediate transfer belt 78 are transferred onto the recording medium P conveyed to the position of the secondary transfer nip. At this time, untransferred toner that has not been transferred to the recording medium P remains on the intermediate transfer belt 78.
Thereafter, the intermediate transfer belt 78 reaches the position of the intermediate transfer cleaning unit 80. At this position, the untransferred toner on the intermediate transfer belt 78 is collected.
Thus, a series of transfer processes performed on the intermediate transfer belt 78 is completed.

Here, the recording medium P transported to the position of the secondary transfer nip is transported from the paper feed unit 22 disposed below the main body of the image forming apparatus via the paper feed roller 97, the registration roller pair 98, and the like. It has been done.
Specifically, a plurality of recording media P such as transfer paper are stored in the paper supply unit 22 in a stacked manner. When the paper feed roller 97 is rotated counterclockwise in FIG. 18, the uppermost recording medium P is fed between the rollers of the registration roller pair 98.

  The recording medium P conveyed to the registration roller pair 98 is temporarily stopped at the position of the roller nip of the registration roller pair 98 that has stopped rotating. Then, the registration roller pair 98 is rotationally driven in synchronization with the color image on the intermediate transfer belt 78, and the recording medium P is conveyed toward the secondary transfer nip. In this way, a desired color image is transferred onto the recording medium P.

  Thereafter, the recording medium P on which the color image is transferred at the position of the secondary transfer nip is conveyed to the fixing device 20 of the present invention. In the fixing device 20, the color image transferred on the surface is fixed on the recording medium P by the heat and pressure generated by the belt member 8 and the pressure member (pressure roller) 7.

Thereafter, the recording medium P is discharged out of the apparatus through a pair of paper discharge rollers 99. The transferred P discharged from the apparatus by the discharge roller pair 99 is sequentially stacked on the stack unit 100 as an output image.
Thus, a series of image forming processes in the image forming apparatus is completed.

DESCRIPTION OF SYMBOLS 1 Side plate 2 Stay member 3 Belt holding member 3a Outer flange 3b Inner flange 4 Sliding member 5 Nip part forming member 6 Elastic body 7 Pressure member (pressure roller)
8 Belt member 9 Heating means 10 Lubricant supply means 11 Drive roller 12 Drive shaft

Japanese Patent Laying-Open No. 2005-300661 JP 2012-145633 A JP2013-11659A

Claims (9)

A fixing device for fixing a toner image on a recording medium,
A pressurizing member arranged rotatably,
A sleeve-like belt member having flexibility and rotating while contacting the pressure member;
A nip portion forming member that is disposed on the inner peripheral side of the belt member and forms a nip portion when the pressure roller contacts the outer peripheral surface of the belt member;
A stay member that supports the nip portion forming member against the pressing force when the belt member and the nip portion forming member are pressed against the pressure roller;
A sliding member that covers an outer peripheral surface including a surface that contacts the inner peripheral surface of the belt member of the nip portion forming member,
The fixing device, wherein the sliding member is an endless sheet rotatably disposed on an outer peripheral surface of the nip portion forming member.   The elastic member is provided between the stay member and the nip portion forming member, and the stay member and the nip portion forming member are separated by urging of the elastic body. Fixing device.   3. The lubricant according to claim 1, further comprising a lubricant supply unit on a surface of the stay member facing the nip forming member, wherein the sliding member is supplied with the lubricant from the lubricant supply unit. The fixing device described.   4. The fixing device according to claim 1, further comprising a driving roller that is disposed in contact with an inner peripheral surface of the sliding member and assists the rotation of the sliding member. 5.   The fixing device according to claim 1, wherein the sliding member rotates with the rotation of the belt member.   The fixing device according to claim 4, wherein the driving roller is connected to a driving source, and the sliding member is rotated by power from the driving source.   7. The control device according to claim 4, further comprising a control unit configured to control rotation of the sliding member, wherein the control unit rotates the sliding member as a predetermined rotation time elapses. Fixing device.   The fixing device according to claim 1, wherein the sliding member rotates when the pressure roller is depressurized away from the belt member. An image forming apparatus comprising the fixing device according to claim 1.