JP2020013046A - Fixing device and image forming apparatus - Google Patents

Abstract

To provide a fixing device that can maintain a low slide resistance when a fixing member rotates, and an image forming apparatus.SOLUTION: A fabric member 81 in contact with an inner surface 21 of a fixing member 2 is held by holding means, and thereby a warp 816 is inclined from end parts in a width direction toward a center part from an upstream side toward a downstream side in a rotation direction of the fixing member 2. A lubricant attached to the inner surface 21 of the fixing member 2 is guided to be directed to the center part in the width direction when the fixing member 2 rotates. The lubricant is prevented from flowing toward the end parts in the width direction of the fixing member 2 and leakage of the lubricant is prevented. The lubricant is not required to be absorbed for leakage prevention, and thereby the total amount of the lubricant on the inner surface 21 of the fixing member 2 is not easily reduced. A deficiency in lubricant on the inner surface 21 of the fixing member 2 does not easily occur, and thereby a low slide resistance when the fixing member 2 rotates can be maintained.SELECTED DRAWING: Figure 4

Description

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

  In general, as a fixing device used in an image forming apparatus, a fixing device including an endless cylindrical fixing member (fixing belt) and a pressing member is known. In such a fixing device, a nip portion is formed by the fixing member and the pressing member, and the toner is pressed and heated in the nip portion to fix the toner on the recording paper.

  As such a fixing device, there has been proposed a fixing device in which a lubricant is applied to an inner surface of a fixing belt so that the fixing belt can be easily slid with respect to a member arranged inside the fixing belt (for example, see Patent Document 1). 1). In the fixing device described in Patent Literature 1, a groove is formed on an outer peripheral surface of an absorbing member supporting member disposed inside a fixing belt, and a lubricant absorbing member is disposed in the groove to fix lubricant. It suppresses leakage from the end of the belt.

  However, in the fixing device described in Patent Document 1, when the lubricant flows toward the widthwise end of the fixing belt, even if the leakage can be suppressed, the lubricant is absorbed by the lubricant absorbing member. Therefore, the total amount of the lubricant attached to the fixing belt may be reduced. At this time, the lubricant tends to run short particularly at the center in the width direction of the fixing belt. If the amount of the lubricant is insufficient, the sliding resistance between the fixing belt and the inner member becomes high, and it becomes difficult for the fixing belt to rotate smoothly.

  SUMMARY OF THE INVENTION It is an object of the present invention to provide a fixing device and an image forming apparatus that can keep a sliding resistance when a fixing member rotates.

  In order to solve the above problems, the invention according to claim 1 includes a pressing member, an endless cylindrical fixing member provided to face the pressing member, a heating source for heating the fixing member, A nip forming unit that forms a nip portion by being disposed on the opposite side of the pressing member with a fixing member interposed therebetween, a supply unit that supplies a lubricant to an inner surface of the fixing member on the nip forming unit side, Wherein the nip forming unit has a woven member that contacts the inner surface, and a holding unit that holds the woven member, wherein the holding unit is at least a width direction of the woven member. Fixing the woven fabric member so that the warps on both sides are inclined from the end in the width direction toward the center from the upstream side to the downstream side in the rotation direction of the fixing member. On the device That.

  According to the fixing device of the present invention, the woven fabric member is held by the holding unit, so that the warp goes from the end in the width direction to the center as going from the upstream side to the downstream side in the rotation direction of the fixing member. To be inclined. Since the textile member contacts the inner surface of the fixing member, the lubricant attached to the inner surface moves along the warp. Therefore, the lubricant attached to the inner surface of the fixing member is guided toward the center in the width direction when the fixing member rotates. Accordingly, the lubricant is prevented from flowing toward the widthwise end of the fixing member, and the leakage of the lubricant is suppressed. At this time, since it is not necessary to absorb the lubricant in order to suppress leakage, the total amount of the lubricant on the inner surface of the fixing member does not easily decrease. Therefore, a shortage of the lubricant hardly occurs on the inner surface of the fixing member, and the sliding resistance when the fixing member rotates can be kept low.

FIG. 2 is a cross-sectional view illustrating the fixing device according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically illustrating an image forming apparatus provided with the fixing device. FIG. 3 is a plan view illustrating a main part of a nip forming unit of the fixing device. FIG. 3 is a plan view schematically illustrating a flow of a lubricant in a fixing member of the fixing device. FIG. 4 is a cross-sectional view schematically illustrating an operation of the fixing device. FIG. 9 is a plan view illustrating a textile member in a fixing device according to a second embodiment of the present invention. FIG. 3 is a perspective view illustrating a holding unit in the fixing device. FIG. 3 is a plan view showing the holding unit. FIG. 3 is a plan view schematically illustrating a flow of a lubricant in a fixing member of the fixing device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the second embodiment, the same components as those described in the first embodiment and components having the same functions are denoted by the same reference numerals as in the first embodiment, and description thereof is omitted.

[First Embodiment]
The fixing device 1 according to the present embodiment is provided in an image forming apparatus (see FIG. 2) 100. As shown in FIG. 1, a fixing member 2, a heating source 3, a pressure member 4, a nip Forming means 5.

[Fixing device]
The fixing member 2 is, for example, a metal belt such as nickel or SUS, or a belt formed in an endless cylindrical shape using a resin material such as polyimide, and may be a film. The surface layer of the belt has a release layer such as a PFA or PTFE layer, and has a release property so that toner does not adhere. An elastic layer formed of a silicone rubber layer or the like may be provided between the base material of the belt and the PFA or PTFE layer. If there is no silicone rubber layer, the heat capacity will be small and the fixability will be improved. Gloss unevenness (Yuzu skin image) tends to remain. In order to improve this, it is preferable to provide a silicone rubber layer of 100 μm or more. Due to the deformation of the silicone rubber layer, minute unevenness is absorbed, and the yuzu skin image is improved.

  A support member (stay) 6 for supporting the nip forming means 5 is provided inside the fixing member 2 to prevent the nip forming means 5 from receiving a pressure by the pressing member 4 to bend and to provide a uniform nip in the axial direction. The width can be obtained.

  Further, the fixing device 1 includes a reflecting member 7 between the heating source 3 and the supporting member 6, and wasteful energy consumption due to heating of the supporting member 6 by radiant heat from the heating source 3 is suppressed. I have. Here, the same effect can be obtained by performing heat insulation or mirror finishing on the surface of the support member 6 instead of providing the reflection member 7.

  The heating source 3 may be a halogen heater as shown, but may be an IH, a resistance heating element, a carbon heater, or the like. The fixing member 2 is directly heated from the inner peripheral side by the heating source 3. When the heating source 3 is a halogen heater, the fixing device 1 may have a light shielding plate. The light-shielding plate blocks light emitted by the halogen heater so that the fixing member 2 is heated within a range corresponding to the size of the recording paper. The light-shielding plate has a light-passing portion corresponding to various types of recording paper, and an appropriate light-passing portion is positioned between the heating source 3 and the fixing member 2 by, for example, rotating. .

  The pressing member 4 is provided with an elastic rubber layer 4B outside the cored bar 4A, and a release layer (PFA or PTFE layer) (not shown) is provided on the surface of the elastic rubber layer 4B to obtain releasability. ing. The pressing member 4 is rotated by a driving force transmitted from a driving source such as a motor provided in the image forming apparatus 100 shown in FIG. 2 via a gear. Further, the pressing member 4 is pressed against the fixing member 2 by a spring or the like, and has a predetermined nip width by crushing and deforming the elastic rubber layer 4B.

  The pressure roller may be a hollow roller or may have a heating source such as a halogen heater. The elastic rubber layer may be solid rubber, but if there is no heater inside the pressure roller, sponge rubber may be used. The use of sponge rubber is more preferable because the heat insulating property is enhanced and the heat of the fixing sleeve is hardly deprived.

  The nip forming means 5 is arranged inside the fixing member 2, that is, on the opposite side of the pressing member 4 with the fixing member 2 interposed therebetween. As a result, a nip portion N is formed by the fixing member 2 and the pressing member 4 which are arranged to face each other. The recording paper onto which the toner image has been transferred passes through the nip N, and is heated and pressed, so that the toner image is fixed on the recording paper.

  In FIG. 1, the shape of the nip portion N is flat, but it may be concave or another shape. (If the shape of the nip portion is concave, the discharge direction of the leading end of the recording paper is closer to the pressure roller, and the separability is improved, so that the occurrence of jam is suppressed.)

  The nip forming unit 5 has a low friction member 8 at a position where the nip forming unit 5 comes into contact with the inner surface (the surface on the nip forming unit 5 side) 21 of the fixing member 2. The low-friction member 8 has a woven fabric member 81 impregnated with a lubricant, supplies the lubricant to the inner surface 21 of the fixing member 2, and functions as a supply unit. Incidentally, examples of the lubricant include silicone oil and grease. Details of the low friction member 8 will be described later.

  The fixing member 2 rotates together with the rotation of the pressing member 4. In the embodiment shown in FIG. 1, the pressing member 4 is rotated by the driving source, and the driving force is transmitted to the belt at the nip portion N, so that the fixing member 2 is rotated. The fixing member 2 rotates while being sandwiched by the nip portion N, and the holding member is inserted and guided at both ends except the nip portion N to travel.

  With the above configuration, it is possible to realize an inexpensive fixing device that warms up quickly.

[Image forming apparatus]
Next, the configuration of the image forming apparatus 100 using the above configuration will be described with reference to FIG.

  The image forming apparatus 100 shown in FIG. 2 is a color printer using a tandem system in which image forming units for forming a plurality of color images are arranged side by side along the belt extending direction. The present invention is not limited to this method, and can be applied not only to printers but also to copiers and facsimile machines.

  In FIG. 2, the image forming apparatus 100 includes photosensitive drums 20Y, 20C, and 20M as image carriers capable of forming images as images corresponding to colors separated into yellow, cyan, magenta, and black, respectively. A tandem structure in which 20 Bk are juxtaposed is adopted.

  In the image forming apparatus 100 having the configuration shown in FIG. 2, the visible image formed on each of the photosensitive drums 20Y, 20C, 20M, and 20Bk is moved in the direction of arrow A1 while facing each of the photosensitive drums 20Y, 20C, 20M, and 20Bk. The primary transfer process is performed on an intermediate transfer body (hereinafter, referred to as a transfer belt) 11 that uses an endless belt that can be moved to each other, and each image is superimposed and transferred. Thereafter, the secondary transfer process is performed on the recording paper S on which a recording sheet or the like is used, so that the recording paper S is collectively transferred.

  Image forming means for performing image forming processing according to the rotation of the photosensitive drums 20Y, 20C, 20M, and 20Bk is arranged around each of the photosensitive drums 20Y, 20C, 20M, and 20Bk. Here, a description will be given of the photosensitive drum 20Bk that performs black image formation. A charging device 30Bk that performs an image forming process along the rotation direction of the photosensitive drum 20Bk, a developing device 40Bk, a primary transfer roller 12Bk, And a cleaning device 50Bk. For writing performed after the charging, the optical writing device 60 is used.

  In the superimposition transfer onto the transfer belt 11, the visible images formed on the photosensitive drums 20Y, 20C, 20M, and 20Bk are transferred to the same position on the transfer belt 11 while the transfer belt 11 moves in the A1 direction. Is done. That is, the voltage is applied by the primary transfer rollers 12Y, 12C, 12M, and 12Bk disposed opposite to the photosensitive drums 20Y, 20C, 20M, and 20Bk with the transfer belt 11 interposed therebetween, so that the upstream side in the A1 direction is downstream. The timing is shifted toward.

  The photoconductor drums 20Y, 20C, 20M, and 20Bk are arranged in this order from the upstream side in the A1 direction. The photosensitive drums 20Y, 20C, 20M, and 20Bk are provided in image stations for forming yellow, cyan, magenta, and black images, respectively.

  The image forming apparatus 100 is disposed so as to face four image stations for performing image forming processing for each color, and above the photosensitive drums 20Y, 20C, 20M, and 20Bk, and includes a transfer belt 11 and a primary transfer roller 12Y. , 12C, 12M, and 12Bk, a secondary transfer roller 14 that is a transfer roller that is disposed opposite to the transfer belt 11, is a transfer roller that is driven by the transfer belt 11 and rotates. A cleaning device 13 for the intermediate transfer belt disposed opposite to the transfer belt 11 for cleaning the transfer belt 11, and an optical writing device as an optical writing device disposed below and below these four image stations. And a device 60.

  The optical writing device 60 includes a semiconductor laser as a light source, a coupling lens, an fθ lens, a toroidal lens, a turning mirror, a rotating polygon mirror as a deflecting unit, and the like. The optical writing device 60 writes the writing light Lb corresponding to each of the photosensitive drums 20Y, 20C, 20M, and 20Bk for each color (in FIG. 2, for convenience, only the black image station is assigned a code. However, the same applies to other image stations) to form electrostatic latent images on the photosensitive drums 20Y, 20C, 20M, and 20Bk.

  The image forming apparatus 100 includes a sheet feeding device 70 as a sheet cassette loaded with recording paper S conveyed between the photosensitive drums 20Y, 20C, 20M, and 20Bk and the transfer belt 11, and a sheet feeding device. The recording sheet S conveyed from the feeding device 70 is transferred to the transfer unit 11 between the transfer belt 11 and each of the photosensitive drums 20Y, 20C, 20M, and 20Bk at a predetermined timing corresponding to the timing of forming the toner image by the image station. , And a sensor (not shown) for detecting that the leading end of the recording paper S has reached the pair of registration rollers 810.

  The image forming apparatus 100 includes a fixing device 1 as a fixing unit of a roller fixing type for fixing the toner image on the recording sheet S to which the toner image has been transferred, and a main body of the image forming apparatus 100 with the fixed recording sheet S. A paper discharge roller 820 for discharging to the outside, a paper discharge tray 83 disposed on an upper part of the main body of the image forming apparatus 100 and stacking the recording paper S discharged from the main body of the image forming apparatus 100 by the paper discharge roller 820; Toner bottles 9Y, 9C, 9M, 9Bk, which are located below the discharge tray 83 and are filled with yellow, cyan, magenta, and black toners, are provided.

  The transfer belt unit 10 includes, in addition to the transfer belt 11, the primary transfer rollers 12Y, 12C, 12M, and 12Bk, a drive roller 15 around which the transfer belt 11 is wound and a driven roller 16.

  The driven roller 16 also has a function as a tension urging unit for the transfer belt 11. Therefore, the driven roller 16 is provided with an urging unit using a spring or the like. Such a transfer belt unit 10, the primary transfer rollers 12Y, 12C, 12M, and 12Bk, the secondary transfer roller 14, and the cleaning device 13 constitute a transfer device 10A.

  The sheet feeding device 70 is provided at a lower portion of the main body of the image forming apparatus 100, and has a feeding roller 84 as a sheet feeding roller that contacts the upper surface of the uppermost recording sheet S. By rotating the feed roller 84 in the counterclockwise direction, the uppermost recording sheet S is fed toward the registration roller pair 810.

  Although not shown in detail, the cleaning device 13 provided in the transfer device 10A includes a cleaning brush and a cleaning blade disposed so as to face and contact the transfer belt 11. The transfer belt 11 is cleaned by scraping off and removing foreign matters such as residual toner on the transfer belt 11 with a cleaning brush and a cleaning blade.

  The cleaning device 13 has a discharge unit (not shown) for carrying out and discarding the residual toner removed from the transfer belt 11.

  The image forming apparatus 100 further includes an operation panel (not shown) for operating the entire apparatus, and a control unit (not shown) for controlling the entire apparatus.

  When the number of sheets passed, the operation time, the number of rotations of the fixing member 2, and the like become equal to or more than a predetermined value, the control unit displays on the operation panel that maintenance of the fixing member 2 is necessary (maintenance display). Functions as display means. That is, the control unit displays whether or not maintenance is required on the operation panel at predetermined operation intervals. When maintenance is performed, the control unit stops the maintenance display and restarts counting of the number of sheets passed, the operation time, the number of rotations of the fixing member 2, and the like.

[Low friction member]
Next, details of the low friction member 8 in the fixing device 1 will be described with reference to FIGS. The low friction member 8 has a woven fabric member 81 which is a continuous sheet-like member, and holding means 82 around which the woven fabric member 81 is wound.

  The textile member 81 is formed in a rectangular shape (band shape) in which the rotation direction of the fixing member 2 is the short side direction and the width direction is the long side direction. The central portion of the fabric member 81 in the rotation direction is a contact region 81A that contacts the inner surface 21 of the fixing member 2, and both ends in the rotation direction are held regions 81B and 81C held by the holding unit 82.

  Four held portions 811 to 814 arranged in the width direction are formed in the held region 81B on the upstream side in the rotation direction. The held portions 811 to 814 are through holes formed in a rectangular shape. One held portion 815 is formed in the held region 81C on the downstream side in the rotation direction. The held portion 815 is a rectangular through hole extending along the width direction.

  The holding means 82 is formed separately from the main body of the nip forming means 5 and is fixed to the main body. The holding means 82 is formed in a rectangular plate shape having a long side in the width direction. The holding means 82 is superimposed on a surface (non-contact surface) of the textile member 81 opposite to the contact surface with the inner surface 21 in the contact region 81A. The woven fabric member 81 may be directly wound around the main body of the nip forming means 5 so that the main body functions as the holding means. The holding means 82 is made of a member such as resin or metal that is less likely to shrink in heat than the woven member 81.

  Eight holding portions 821 to 828 are formed on the surface of the holding means 82 opposite to the surface on which the fabric member 81 is overlapped. The holding portions 821 to 828 are projections formed in a quadrangular prism shape. The width dimension of the holding parts 821 to 828 is substantially equal to or slightly smaller than the width dimension of the held parts 811 to 814. The rotation direction dimensions of the holding units 821 to 828 are substantially equal to or slightly smaller than the rotation direction dimensions of the held units 811 to 815.

  The distance L1 between one edge of the holding portions 821 and 825 on one side in the width direction (left side in FIG. 3) and the other edge of the holding portions 824 and 828 on the other side (right side in FIG. 3) in the width direction is , Smaller than the widthwise dimension L2 of the held portion 815. A half of the difference between the distance L1 and the dimension L2 is defined as ΔL.

  In the state where the holding means 82 is superimposed on the non-contact surface of the textile member 81 as described above, the held regions 81B and 81C of the textile member 81 are folded back toward the holding means 82 (the front side in FIG. 3), so that the Each of the holding portions 821 to 824 is inserted into each of the holding portions 811 to 814, and the holding portions 825 to 828 are inserted into the held portion 815. Thus, the fabric member 81 is held by the holding means 82.

  Between the holding portions 825 and 828 at both ends in the width direction and the inner edge of the held portion 815, a gap having a dimension ΔL is formed on one side in the width direction. Therefore, the fabric member 81 can be contracted by the dimension ΔL on one side in the width direction in the held area 81C on the downstream side. In other words, the shrinkage of the fabric member 81 that is larger than the dimension ΔL on one side in the width direction in the held area 81C is regulated. Note that the gap between the holding portion 825 and the inner edge of the held portion 815 may be slightly different from the gap between the holding portion 828 and the inner edge of the held portion 815.

  On the other hand, since the width direction dimensions of the holding portions 821 to 828 are substantially equal to or slightly smaller than the width direction dimensions of the held portions 811 to 814, the textile member 81 almost contracts in the upstream held region 81B. And shrinkage is regulated. As described above, the holding unit 82 holds the woven fabric member 81 so as to regulate the contraction in the width direction, and the regulating force on the upstream side is stronger than the regulating force on the downstream side.

  When the fixing device 1 operates, the temperature of the fixing member 2 rises due to heat generated by the heating source 3 and frictional heat generated in each part, and the fabric member 81 in contact with the fixing member 2 is also heated and tends to thermally contract. At this time, as described above, the contraction in the width direction of the woven fabric member 81 is regulated by the holding means 82, and the regulating force on the upstream side is stronger than the regulating force on the downstream side. The warp 816 and the plurality of wefts 817 have shapes as shown in FIG. FIG. 4 shows the inner surface 21 of the fixing member 2 and the fabric member 81 is not actually seen, but for convenience of explanation, the fabric member 81 is shown on the inner surface 21 in an overlapping manner.

  Except for the warp 816, except for the one arranged at the center in the width direction, the plurality of warps 816 are inclined and extended from the end in the width direction toward the center from the upstream side to the downstream side in the rotation direction of the fixing member 2. Exist. The lubricant adhered to the inner surface 21 of the fixing member 2 is guided by the warp 816, and moves along the extending direction of the warp 816 when the fixing member 2 rotates and passes through the nip N. On the other hand, the plurality of wefts 817 are convexly curved toward the upstream side in the rotation direction, and the vertices of the convex shape are located at the center in the width direction. The curvature of the weft 817 increases toward the end in the width direction.

  The plurality of warps 816 are arranged in the width direction, and the closer to the end in the width direction, the larger the inclination angle θ with respect to the rotation direction. Assuming that the rotational dimension of the contact area 81A is S, the lubricant guided by the warp 816 moves toward the center in the width direction by Stan θ. In the case where the fixing member 2 does not contact the woven fabric member 81 other than at the nip portion N, or when the pressing force is small even if the fixing member 2 contacts the woven fabric member 81, the nip width (the size of the nip portion N in the rotation direction) is LN, and May move toward the center in the width direction by LNtan θ.

  The fabric member 81 has a plurality of wefts 817 having different colors from each other. In the illustrated example, four of the five wefts 817 indicated by solid lines are black, and one indicated by broken lines is red. Note that the plurality of wefts 817 may be composed of three or more colors.

  Assuming that the rotational direction dimension of the weft 817 (the amount of bending from the center to the end in the width direction) is L0, the rotational direction dimension L0 of the weft 817 is preferably 8 to 40% of the rotational direction dimension S of the contact area 81A. . Further, assuming that the width of the contact area 81A is W, it is preferable that the rotation direction dimension L0 of the weft 817 is 0.4 to 2% of the width W.

  According to this embodiment, the following effects can be obtained. That is, by holding the fabric member 81 in contact with the inner surface 21 of the fixing member 2 by the holding means 82, the warp 816 is shifted from the upstream side to the downstream side in the rotation direction of the fixing member 2 in the widthwise end portion. From the center to the center. Therefore, the lubricant attached to the inner surface 21 of the fixing member 2 is guided toward the center in the width direction when the fixing member 2 rotates.

  This suppresses the flow of the lubricant toward the end in the width direction of the fixing member 2, and suppresses the leakage of the lubricant. At this time, since it is not necessary to absorb the lubricant to suppress leakage, the total amount of the lubricant on the inner surface 21 of the fixing member 2 is not easily reduced. Therefore, a shortage of the lubricant hardly occurs on the inner surface 21 of the fixing member 2, and the sliding resistance when the fixing member 2 rotates can be kept low.

  Further, the fabric member 81 may be attached with a slight inclination with respect to the original position due to a manufacturing error or the like. For example, the warp 816 arranged at the center in the width direction may be inclined with respect to the rotation direction. In such a case, although the position where the lubricant gathers is slightly shifted from the central portion in the width direction, the leakage of the lubricant from the end portion of the fixing member 2 is suppressed, and the shortage of the lubricant hardly occurs.

  Furthermore, since the plurality of warps 816 are located closer to the end in the width direction, the inclination angle θ is larger, so that the lubricant is easily directed to the center particularly at the end in the width direction, and Of the lubricant can be further suppressed.

  Further, since the weft 817 of the woven fabric member 81 is convexly curved toward the downstream side in the rotation direction, the degree of this curvature can be measured, and the inclination angle θ of the warp 817 can be managed. In addition, since the curvature of the weft 817 is larger toward the end in the width direction, the inclination angle θ is more likely to be increased as the plurality of warps 816 are positioned closer to the end in the width direction.

  Furthermore, since the textile member 81 has a plurality of wefts 817 having different colors from each other, the shape of the wefts 817 can be easily recognized, and the amount of bending of the wefts 817 can be easily measured.

  Further, since the woven fabric member 81 is one continuous sheet-shaped member, it is possible to suppress the lubricant from leaking from the gap between the sheets.

[Second embodiment]
As in the first embodiment, the fixing device of the present embodiment includes a fixing member 2, a heating source 3, a pressing member 4, and a nip forming unit. In the present embodiment, the nip forming means is different from that of the first embodiment.

  That is, in the present embodiment, the low friction member of the nip forming means has a textile member 91 as shown in FIG. 6 and a holding means 92 as shown in FIGS.

  The textile member 91 is formed in a rectangular shape (band shape) in which the rotation direction of the fixing member 2 is the short side direction and the width direction is the long side direction. The center of the fabric member 91 in the rotation direction is a contact area 91A that contacts the inner surface 21 of the fixing member 2, and both ends in the rotation direction are held areas 91B and 91C held by the holding unit 92.

  Each of the held areas 91B and 91C is formed with a plurality of (ten upper and lower pieces in the illustrated example) held sections 911 arranged in the width direction. The held portion 911 is a through hole formed in a rectangular shape. The plurality of held portions 911 have a linear array shape (first shape).

  The holding means 92 is formed separately from the main body of the nip forming means 5 and is fixed to the main body. The holding means 92 is formed in a rectangular plate shape having a long side in the width direction. The holding means 92 is superimposed on a surface (non-contact surface) of the textile member 91 opposite to the contact surface with the inner surface 21 in the contact region 91A. The woven fabric member 91 may be directly wound around the main body of the nip forming means 5 so that the main body functions as the holding means.

  A plurality of (in the illustrated example, a total of 20) holding portions 921 are formed on the surface of the holding means 92 opposite to the surface on which the fabric member 91 is superimposed. The holding portion 921 is a projection formed in an elliptical column shape. The plurality of holding portions 921 are arranged in two rows, and each row has an array shape (second shape) curved along the width direction and convexly upstream in the rotation direction.

  In the state where the holding means 92 is superimposed on the non-contact surface of the textile member 91 as described above, the held areas 91B and 91C of the textile member 91 are folded back toward the holding means 92, thereby holding the holding parts 911 respectively. Each of the parts 921 is inserted.

  At this time, since the first arrangement shape of the held portion 911 and the second arrangement shape of the holding portion 921 are different from each other, the fabric member 91 is deformed before and after holding. The plurality of warps 916 and the plurality of wefts 917 constituting the woven fabric member 91 have shapes as shown in FIG. Note that FIG. 9 shows the inner surface 21 of the fixing member 2 and the fabric member 91 is not actually seen. However, for convenience of explanation, the fabric member 91 is overlapped on the inner surface 21 and shown.

  The plurality of warps 916 and the plurality of wefts 917 of the present embodiment have the same shape as the plurality of warp 816 and the plurality of wefts 817 of the first embodiment.

  In the present embodiment, the first arrangement shape of the held portion 911 is linear, and the second arrangement shape of the holding portion 921 is curved, but at least one of the arrangement shapes is curved. I just need. For example, the first arrangement shape of the held portions may be a shape curved convexly to the downstream side, and the second arrangement shape of the holding portions may be linear. Further, the first arrangement shape of the held portion may be a shape convexly curved to the downstream side, and the second arrangement shape of the holding portion may be a shape curved convexly to the upstream side.

  According to this embodiment, the following effects can be obtained. That is, by holding the fabric member 91 in contact with the inner surface 21 of the fixing member 2 by the holding means 92, the warp yarn 916 has an end in the width direction from the upstream side to the downstream side in the rotation direction of the fixing member 2. From the center to the center. Therefore, the lubricant attached to the inner surface 21 of the fixing member 2 is guided toward the center in the width direction when the fixing member 2 rotates.

  This suppresses the flow of the lubricant toward the end in the width direction of the fixing member 2, and suppresses the leakage of the lubricant. At this time, since it is not necessary to absorb the lubricant to suppress leakage, the total amount of the lubricant on the inner surface 21 of the fixing member 2 is not easily reduced. Therefore, a shortage of the lubricant hardly occurs on the inner surface 21 of the fixing member 2, and the sliding resistance when the fixing member 2 rotates can be kept low.

  Further, the fabric member 91 may be attached with a slight inclination with respect to the original position due to a manufacturing error or the like. For example, the warp 916 disposed at the center in the width direction may be inclined with respect to the rotation direction. In such a case, although the position where the lubricant gathers is slightly shifted from the central portion in the width direction, the leakage of the lubricant from the end portion of the fixing member 2 is suppressed, and the shortage of the lubricant hardly occurs.

  The present invention is not limited to the above-described embodiment, but includes other configurations and the like that can achieve the object of the present invention, and includes the following modifications and the like.

  For example, in the first embodiment, the one in which the plurality of warps 816 are located closer to the end in the width direction has a larger inclination angle θ, but the present invention is not limited to such a configuration. The plurality of warps 816 may have the same inclination angle θ except that at the center, or the inclination angle θ may be smaller at the end side of the warp 816. The magnitude of the inclination angle θ may be a magnitude corresponding to the inclination of the woven fabric member 81 that may occur during manufacturing, and may be set as appropriate.

  In the first embodiment, the fabric member 81 has a plurality of wefts 817 having different colors from each other. However, when it is easy to measure the amount of curvature of the warp, the plurality of wefts are mutually connected. It may be the same color. For example, depending on the thickness and luster of the yarn, the roughness of the weave, and the like, even if a plurality of wefts have the same color, the shape may be easily visually observed and the measurement of the amount of bending may be easy. In addition, even when the amount of curvature is easy to manage in fabricating the fabric or when the error in the amount of curvature is small, a plurality of wefts may have the same color.

  Further, in the first embodiment, the curvature of the weft 817 is set to be larger toward the end in the width direction, but the curvature of the weft may be set so that the warp has an appropriate inclination angle. For example, it may be substantially constant from the center to the end in the width direction.

  In the first embodiment, the fabric member 81 functions as a supply unit that supplies the lubricant to the inner surface 21 of the fixing member 2. However, the supply unit is provided separately from the member that forms the contact unit. It may be provided.

  In addition, the best configuration and method for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, although the present invention has been particularly shown and described with particular reference to particular embodiments, the present invention will be understood by those skilled in the art without departing from the spirit and scope of the invention. The trader can make various modifications.

  Therefore, the description in which the shapes, materials, and the like disclosed above are limited is merely illustrative for facilitating the understanding of the present invention, and does not limit the present invention. A description of a part of a member excluding some or all of the restrictions such as the shape and the material is included in the present invention.

DESCRIPTION OF SYMBOLS 1 Fixing apparatus 2 Fixing member 21 Inner surface 3 Heat source 4 Pressurizing member 5 Nip forming means 5A, 5B Contact part 8 Low friction member (supply means)
81, 91 Textile member 82, 92 Holding means 816, 916 Warp 817, 917 Weft 911 Held part 921 Held part 100 Image forming apparatus

JP 2008-26603 A

Claims (8)

A pressing member, an endless cylindrical fixing member provided to face the pressing member, a heating source for heating the fixing member, and a heating member disposed on the opposite side of the pressing member across the fixing member. A fixing device comprising: a nip forming unit that forms a nip portion by supplying a lubricant to an inner surface of the fixing member on the nip forming unit side;
The nip forming unit has a woven member that contacts the inner surface, and a holding unit that holds the woven member,
The holding means is such that at least the warp yarns on both sides in the width direction of the woven fabric member are inclined from the end in the width direction toward the center as going from the upstream side to the downstream side in the rotation direction of the fixing member. A fixing device for holding the textile member.   In the woven fabric member held by the holding means, the warp guides the lubricant so as to move from the end in the width direction toward the center when the fixing member rotates. Item 2. The fixing device according to Item 1.   3. The woven fabric member held by the holding means, wherein the warp is located closer to the end in the width direction, and has a larger inclination angle with respect to the rotation direction. 4. Fixing device.   In the woven fabric member held by the holding means, the weft of the woven fabric member is convexly curved toward the upstream side in the rotation direction, and has a larger curvature toward the end in the width direction. The fixing device according to claim 1.   The fixing device according to claim 1, wherein the woven member is a single continuous sheet member.   The holding means holds the textile member so as to regulate shrinkage in the width direction, and the regulating force on the upstream side is stronger than the regulating force on the downstream side. 6. The fixing device according to any one of items 5 to 5. The woven member has a plurality of held portions arranged in a predetermined first shape along the width direction,
The holding means has a plurality of holding portions arranged in a predetermined second shape along the width direction,
The said 1st shape and the said 2nd shape differ, the weft of the said textile member curves convexly to the said downstream side, and the said warp inclines, The Claim 1 characterized by the above-mentioned. 3. The fixing device according to claim 1.   An image forming apparatus comprising the fixing device according to claim 1.

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