JP2010072523A - Transfer device and image forming apparatus having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer device which effectively restricts meandering of a transfer belt by accurately positioning a meandering restriction member at a roller, and to provide an image forming apparatus having the same. <P>SOLUTION: The transfer device includes: a transfer belt having a projection streak part; a roller wound with the transfer belt; a bearing member for supporting the roller; a frame for supporting the bearing member; and the meandering restriction member which is disposed coaxially with the roller, and supported by the bearing member or frame. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transfer device provided with a transfer belt in an image forming apparatus such as a printer, a copying machine, and a facsimile, and more specifically, a transfer device provided with a meandering prevention function of the transfer belt, and an image forming device including the transfer device. Relates to the device.

  In an electrophotographic image forming apparatus, an electrostatic latent image formed on an image carrier (photoreceptor) based on electrical image information from a host machine is used using toner supplied from a developing device. Development is performed to form a toner image, and the toner image is transferred onto a transfer material and then fixed to form an image. By the way, in a color image forming apparatus that forms full-color images using yellow, magenta, cyan, and black toners, toner images of different colors formed on a plurality of image carriers are sequentially superimposed on an intermediate transfer belt. Generally, a method is used in which a superposed toner image is formed by transferring, and then the superposed toner image on the intermediate transfer belt is secondarily transferred onto a transfer material. In addition, an image forming apparatus including a transfer belt that conveys a transfer material when a toner image on the intermediate transfer belt is transferred onto the transfer material has been developed.

  Each of these intermediate transfer belts and transfer belts has a configuration for running an endless belt around a roller. In this type of endless belt, smooth running and stability are important for improving the image quality to be formed. For example, even when the endless belt is slightly displaced in the width direction or causes meandering, deterioration of image quality cannot be avoided.

Japanese Patent Application Laid-Open No. 2003-246484 discloses a meandering restricting member in which a protrusion is provided on an endless belt and a guide groove is formed in a roller so that the protrusion is slidably fitted in order to eliminate the meandering of the belt. What has been worn is disclosed.
Japanese Patent Laid-Open No. 2003-246484.

  However, according to the conventional technique, the arrangement size of the meandering restricting member is not accurate, so that the meandering restricting force of the belt cannot be obtained as expected, and the belt may run up.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a transfer device that effectively regulates meandering of a transfer belt by accurately positioning a meandering restricting member and arranging it on a roller. Is provided.

  In order to solve the above problems, the transfer device of the present invention includes a transfer belt having a ridge, a roller around which the transfer belt is wound, a bearing member that supports the roller, and a frame that supports the bearing member. And a meandering restricting member which is arranged coaxially with the roller and supported by the bearing member or the frame. Since the meandering restricting member is supported by the bearing member or the frame supported by the frame, the position of the restricting portion of the meandering restricting member can be accurately positioned with reference to the frame, and the meandering of the transfer belt can be effectively restricted. .

  In the transfer device of the present invention, the meandering restricting member is formed on a cylindrical member rotatably fitted on the shaft of the roller, and is formed at one axial end of the cylindrical member. And a connecting part that is supported by the bearing member or the frame by positioning the position of the restricting part formed at the other axial end of the cylindrical member. The position of the restricting portion can be accurately positioned with a simple connecting portion, and the meandering of the transfer belt can be effectively restricted.

  In the transfer device of the present invention, the connecting portion includes a first engaging convex portion and a first engaging concave portion, and the first engaging convex portion and the first engaging concave portion are the bearing member or the frame. A second engagement recess formed at the end of the second engagement portion and a second coupling portion having a second engagement projection, and a gap is formed in the engagement portion between the first engagement projection and the second engagement recess. Formed. The toner and carrier that have flowed out from the end of the transfer belt flow into the connecting portion between the meandering restricting member and the bearing member through the gap, reducing sliding friction and preventing the flowed out toner and carrier from flowing out to the rotating shaft. .

  In the transfer device of the present invention, the bearing member is integrally formed on the frame. The process of attaching the bearing member to the frame can be omitted.

  In the transfer device of the present invention, the frame is formed by integrally forming a support member for supporting a plurality of bearing members or a plurality of bearing members. The positions of the restricting portions of the plurality of meandering restricting members can be accurately positioned based on the same frame.

  In the transfer device of the present invention, the meandering restricting member is disposed at both axial ends of the roller. A shift to either side of the both sides in the width direction while the transfer belt is running can be handled.

  The image forming apparatus of the present invention also has an image carrier that carries a toner image, a first transfer belt to which the toner image on the image carrier is transferred, and a toner image on the first transfer belt. A second transfer belt that conveys the transfer material, a roller around which the first transfer belt is wound, a bearing member that supports the roller, a frame that supports the bearing member, and the roller. And a meandering restricting member supported by the bearing member or the frame. The meandering of the first transfer belt carrying the toner image can be effectively regulated by accurate positioning of the regulation part of the meandering regulating member, and a high-quality image without image displacement can be obtained.

  Further, the image forming apparatus of the present invention is arranged on the same axis as the roller around which the second transfer belt is wound, a bearing member that supports the roller, a frame that supports the bearing member, and the roller. And a meandering restricting member supported by the bearing member or the frame. The meandering of the second transfer belt can be effectively regulated by the accurate positioning of the regulation part of the meandering regulating member, so that a shift at the time of transfer can be prevented and a high quality image can be obtained.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram schematically and partially showing an example of an embodiment of an image forming apparatus provided with a transfer device according to the present invention.

  As shown in FIG. 1, the image forming apparatus 1 of this example includes a photoreceptor 2Y that is a latent image carrier of yellow (Y), magenta (M), cyan (C), and black (K) arranged in tandem. , 2M, 2C, 2K. Here, in each of the photoreceptors 2Y, 2M, 2C, and 2K, 2Y represents a yellow photoreceptor, 2M represents a magenta photoreceptor, 2C represents a cyan photoreceptor, and 2K represents a black photoreceptor. Similarly, the members of the respective colors are represented by adding Y, M, C, and K of the respective colors to the reference numerals of the members. Each of the photoreceptors 2Y, 2M, 2C, and 2K is composed of a photoreceptor drum in the example shown in FIG. Each of the photoconductors 2Y, 2M, 2C, and 2K can also be configured as an endless belt. Since the configurations of the photoconductors 2Y, 2M, 2C, and 2K are the same, the yellow photoconductor 2Y will be described as an example.

  The photosensitive member 2Y is rotated clockwise as indicated by an arrow in FIG. Around the photoreceptor 2Y, a charging member 3Y, an exposure device 4Y, a developing device 5Y, a photoreceptor squeeze device 6Y, a primary transfer device 7Y, and a photoreceptor cleaning device 8Y are arranged in this order from the upstream side in the rotation direction. Has been.

  Further, the image forming apparatus 1 includes an endless intermediate transfer belt 10 that is an intermediate transfer medium. The intermediate transfer belt 10 is stretched around a belt driving roller 11 and a pair of driven rollers 12 and 13 to which a driving force of a motor (not shown) is transmitted, and is provided to be able to rotate counterclockwise in FIG. In this case, the belt driving roller 11 and the one driven roller 12 are arranged adjacent to each other with a predetermined interval in the moving direction indicated by the arrow of the paper such as the paper being conveyed. The belt driving roller 11 and the other driven roller 13 are spaced apart from each other along the tandem arrangement direction of the photoreceptors 2Y, 2M, 2C, and 2K. Further, the intermediate transfer belt 10 is applied with a predetermined tension in the direction of the arrow on the driven roller 13 so that the slack is removed. Further, the movement direction of the intermediate transfer belt 10 is changed by a pressing roller 63 disposed in the vicinity of the driven roller 12.

  The intermediate transfer belt 10 has a multilayer structure in which an elastic layer is laminated on a base material layer, and a coat layer is formed on the surface of the elastic layer. By adopting a multi-layer structure with an elastic layer, the intermediate transfer belt 10 has an appropriate elasticity in the thickness direction so that transfer of liquid developer images from the photoconductors 2Y, 2M, 2C, and 2K and transfer to paper are possible. In particular, it is excellent in transferability with large unevenness, and a clean image can be transferred to the recesses. The material constituting the base material layer is polyimide resin, polyamideimide resin, or the like, the material constituting the elastic layer is polyurethane rubber or the like, and the material constituting the coat layer is fluororesin or the like. The intermediate transfer belt 10 may have a single layer structure.

  In the image forming apparatus 1 of this example, the photoreceptors 2Y, 2M, 2C, and 2K and the developing devices 5Y, 5M, 5C, and 5K have colors Y, M, C, and C from the upstream side in the rotation direction of the intermediate transfer belt 10, respectively. Although arranged in the order of K, the arrangement order of these colors Y, M, C, and K can be arbitrarily set.

  An intermediate transfer belt squeeze device 15Y is disposed in the vicinity of the primary transfer device 7Y on the downstream side in the rotation direction of the intermediate transfer belt 10 from each primary transfer device 7Y. Further, a secondary transfer device 16 is provided on the belt driving roller 11 side of the intermediate transfer belt 10, and an intermediate transfer belt cleaning device 17 is provided on the driven roller 13 side of the intermediate transfer belt 10.

  Although not shown in the figure, the image forming apparatus 1 of this example places paper such as paper on the upstream side in the paper transport direction from the secondary transfer apparatus 16 as in the conventional general image forming apparatus that performs secondary transfer. A paper storage device for storing paper and a pair of registration rollers for supplying and feeding the paper from the paper storage device to the secondary transfer device 16 are provided. Similarly, the image forming apparatus 1 includes a fixing device and a paper discharge tray on the downstream side in the paper transport direction from the secondary transfer device 16.

  The charging member 3Y includes, for example, a pair of corona chargers. A bias having the same polarity as the charging polarity of the liquid developer is applied to the charging member 3Y from a power supply device (not shown). The charging member 3Y charges the photoreceptor 2Y. The exposure device 4Y forms an electrostatic latent image on the charged photoreceptor 2Y by irradiating laser light from, for example, a laser scanning optical system.

  The developing device 5Y includes a developer supply unit (not shown), a developing roller 19Y, a toner charging corona charger 20Y, and a developing roller cleaner 21Y. In the present embodiment, a development system using a liquid developer will be described as an example, but a dry development system may be used.

  The developer supply unit includes a developer container that stores a liquid developer including toner particles and a nonvolatile liquid carrier, a developer scooping roller 25Y, an anilox roller 26Y, and a developer regulating blade 27Y.

  In the liquid developer housed in the developer container, as the toner, for example, particles having an average particle diameter of 1 μm in which a colorant such as a known pigment is dispersed in a known thermoplastic resin used for the toner are used. be able to. On the other hand, as the liquid carrier, in the case of a low-viscosity low-concentration liquid developer, for example, an insulating liquid carrier of Isopar (trademark: Exxon) can be used. In the case of a liquid developer having a high viscosity and high concentration as a liquid carrier, for example, an organic solvent, a silicone oil having a flash point of 210 ° C. or higher, mineral oil, boiling point, such as phenylmethylsiloxane, dimethylpolysiloxane and polydimethylcyclosiloxane Use an insulating liquid carrier such as aliphatic saturated hydrocarbons such as liquid paraffin with a relatively low viscosity having a viscosity of 3 mPa · s at 170 ° C. or higher and normal viscosity, vegetable oil, edible oil, higher fatty acid ester, etc. Can do. The liquid developer is one in which toner particles are added to a liquid carrier together with a dispersant to make the toner solid content concentration about 20%.

  The developer scooping roller 25Y is a roller that scoops up the liquid developer in the developer container and supplies it to the anilox roller 26Y. The developer pumping roller 25Y is configured to rotate clockwise as indicated by an arrow in FIG. Each of the anilox rollers 26Y is a roller having a cylindrical member and a spiral groove formed on the surface thereof in a fine and uniform manner. For example, the groove pitch is set to about 170 μm and the groove depth is set to about 30 μm. Of course, the dimension of the groove is not limited to these values. The anilox roller 26Y is configured to rotate counterclockwise as indicated by an arrow in FIG. 1 in the same direction as the developing roller 19Y. The anilox roller 26Y can be rotated together with the developing roller 19Y. That is, the rotation direction of the anilox roller 26Y is not limited and is arbitrary.

  Each of the developer regulating blades 27Y is provided in contact with the surface of the anilox roller 26Y. The developer regulating blade 27Y is composed of a rubber portion made of urethane rubber or the like that comes into contact with the surface of the anilox roller 26Y, and a metal plate or the like that supports the rubber portion. The developer regulating blade 27Y scrapes off and removes the liquid developer adhering to the surface other than the groove portion of the anilox roller 26Y with a rubber portion. Therefore, the anilox roller 26Y supplies only the liquid developer adhering in the groove portions to the developing roller 19Y.

  Each of the developing rollers 19Y is a cylindrical member having a width of, for example, about 320 mm. For example, the developing roller 19Y includes an elastic body such as conductive urethane rubber, a resin layer, and a rubber layer on the outer periphery of a metal shaft such as iron. . The developing roller 19Y is in contact with the photoreceptor 2Y and is rotated counterclockwise as indicated by an arrow in FIG.

  The toner charging corona charger 20Y is applied with a voltage to charge the developing roller 19Y.

  Further, each of the developing roller cleaners 21Y is made of, for example, rubber that comes into contact with the surface of the developing roller 19Y, and scrapes and removes the developer remaining on the developing roller 19Y.

  The photoreceptor squeeze device 6Y includes a pair of photoreceptor squeeze rollers 36Y and a photoreceptor squeeze roller cleaner 37Y. The photosensitive member squeeze roller 36Y is disposed on the downstream side in the rotation direction of the photosensitive member 2Y from the contact portion (nip portion) between the photosensitive member 2Y and the developing roller 19Y. The photosensitive member squeeze roller 36Y is rotated in the opposite direction to the photosensitive member 2Y (counterclockwise in FIG. 1) to remove the liquid carrier on the photosensitive member 2Y.

  As the photoreceptor squeeze roller 36Y, an elastic roller in which an elastic member such as conductive urethane rubber and a fluororesin surface layer are arranged on the surface of a metal core is suitable. The photosensitive member squeeze roller cleaner 37Y is made of an elastic material such as rubber and is in contact with the surface of the photosensitive member squeeze roller 36Y, and scrapes off and removes the liquid carrier remaining on the squeeze roller 36Y.

  The primary transfer device 7Y includes a backup roller 39Y for primary transfer that brings the intermediate transfer belt 10 into contact with the photoreceptor 2Y. The backup roller 39Y is applied with, for example, about −200 V having a polarity opposite to the charged polarity of the toner particles, and primarily transfers the yellow toner image (liquid developer image) on the photoreceptor 2Y to the intermediate transfer belt 10.

  The photoconductor cleaning device 8Y includes a photoconductor cleaning roller 43Y disposed on the photoconductor 2Y after the primary transfer, a photoconductor cleaning roller cleaner 44Y, and a photoconductor cleaning blade 45Y.

  The intermediate transfer belt squeeze device 15Y includes an intermediate transfer belt squeeze roller 40Y, an intermediate transfer squeeze backup roller 42Y, and an intermediate transfer belt squeeze roller cleaner 41Y. The intermediate transfer belt squeeze roller 40Y collects the yellow liquid carrier on the intermediate transfer belt 10. The intermediate transfer belt squeeze roller cleaner 41Y scrapes off the collected liquid carrier on the intermediate transfer belt squeeze roller 40Y. The intermediate transfer belt squeeze roller cleaner 41Y is made of an elastic body such as rubber like the squeeze roller cleaner 37Y.

  The intermediate transfer belt cleaning device 17 disposed on the driven roller 13 side of the intermediate transfer belt 10 includes an intermediate transfer belt cleaning roller 50, an intermediate transfer belt cleaning roller cleaner 51, and an intermediate transfer belt cleaning blade 49.

  The secondary transfer device 16 includes a pair of secondary transfer rollers that are spaced apart from each other by a predetermined distance along the sheet moving direction. Of the pair of secondary transfer rollers, the secondary transfer roller disposed on the upstream side in the sheet moving direction is the first secondary transfer roller 43. Of the pair of secondary transfer rollers, the secondary transfer roller disposed on the downstream side in the sheet moving direction is the second secondary transfer roller 44. An endless transfer material conveyance belt 46 is stretched around the first and second secondary transfer rollers 43 and 44. In that case, a tension is applied to the transfer material conveyance belt 46 by a tension roller 60. The first and second secondary transfer rollers 43 and 44 can contact the belt driving roller 11 and the driven roller 12 via the intermediate transfer belt 10 and the transfer material transport belt 46, respectively. The transfer material conveyance belt 46 is made of polyimide resin or polyamideimide resin. A secondary transfer bias is applied from the first and second secondary transfer rollers 43 and 44, and the belt driving roller 11 and the driven roller 12 are grounded.

  That is, the transfer material conveying belt 46 stretched around the first and second secondary transfer rollers 43 and 44 brings the sheet into close contact with the intermediate transfer belt 10 stretched around the belt driving roller 11 and the driven roller 12. The color toner image (liquid developer image) in which the toner images of the respective colors on the intermediate transfer belt 10 are combined is secondarily transferred to the paper while the paper is conveyed with the paper in close contact with the intermediate transfer belt 10. It is like that.

  In that case, the belt driving roller 11 and the driven roller 12 also function as backup rollers for the secondary transfer rollers 43 and 44 during the secondary transfer, respectively. That is, the belt driving roller 11 is also used as a first backup roller disposed in the secondary transfer device 16 on the upstream side of the driven roller 12 in the sheet moving direction. In addition, the driven roller 12 is also used as a second backup roller disposed downstream of the belt driving roller 11 in the sheet transfer direction in the secondary transfer device 16.

  Accordingly, the sheet conveyed to the secondary transfer device 16 is transferred from the pressure contact start position (nip start position) between the first secondary transfer roller 43 and the belt driving roller 11 to the second secondary transfer roller 44 and the driven roller 12. Is in close contact with the intermediate transfer belt 10 in a predetermined movement region of the sheet up to the pressure contact end position (nip end position). As a result, the full-color toner image on the intermediate transfer belt 10 is secondarily transferred over a predetermined time onto a sheet in close contact with the intermediate transfer belt 10, so that good secondary transfer is performed.

  In addition, the secondary transfer device 16 includes a transfer belt cleaner 45 for the transfer material conveyance belt 46. The transfer belt cleaner 45 is made of an elastic material such as rubber similarly to the photoconductor squeeze roller cleaners 37Y, 37M, 37C, and 37K. The transfer belt cleaner 45 is in contact with the transfer material conveyance belt 46 and scrapes off and removes foreign matters such as liquid developer remaining on the surface of the transfer material conveyance belt 46 after the secondary transfer. Therefore, it is possible to prevent the influence of the foreign material such as the liquid developer adhering to the transfer material conveyance belt 46 on the next sheet.

  The color toner image transferred onto the transfer material is fixed by a fixing device (not shown) as in the prior art, and the transfer material on which the full-color fixed image is formed is conveyed to a paper discharge tray, and the color image forming operation is completed. To do.

  The intermediate transfer belt 10 used as a transfer device and the transfer material transport belt 46 are composed of endless belts wound around a plurality of rollers. Such a belt conveying device tends to be displaced in the direction in which the belt exists due to an axial deviation between the rollers or a difference in the inner peripheral length of the belt. In order to eliminate the deviation of the belt, an endless belt is provided with a ridge, and a roller is provided with a meandering regulating member in which a guide groove is formed to slidably fit the ridge. . However, since the arrangement size of such a meandering restricting member is not accurate, the meandering restricting force of the belt cannot be obtained as expected, and the belt may run up.

  FIG. 2 is a diagram illustrating a first embodiment of a transfer device in which the meandering restricting member 102 is disposed at an accurate position coaxial with the roller 101 and the meandering of the transfer belt 100 can be restricted. The meandering regulating member 102 shown in FIG. 2 can be applied to both the intermediate transfer belt 10 and the transfer material shipping belt 46. Therefore, the intermediate transfer belt 10 and the transfer material conveying belt 46 are used as the transfer belt 100, and other members are also described above. The reference numerals different from those of the image forming apparatus of FIG.

  The transfer belt 100 is an endless belt and is wound around a roller 101. The roller 101 includes a driving roller, a driven roller, and a tension roller with a driving mechanism. The roller 101 has a large-diameter central portion 101a around which the transfer belt 100 is wound, and a small-diameter rotating shaft 101b formed at both ends thereof. The large-diameter central portion 101a and the small-diameter rotating shaft 101b are made of a metal such as iron or aluminum, and a surface layer portion made of urethane rubber for preventing slippage is formed on the surface of the large-diameter central portion 101a.

  A meandering restricting member 102 is disposed on at least one of the small-diameter rotating shafts 101b formed at both ends of the roller 101. The meandering restricting member 102 is formed of a cylindrical main body 102b made of a synthetic resin and formed with a hollow portion 102a having an inner diameter slightly larger than the outer diameter of the rotating shaft 101b for being rotatably inserted into the rotating shaft 101b having a small diameter of the roller 101. Is done. The outer diameter of the cylindrical main body 102 b is smaller than the outer diameter of the large central portion 101 a of the roller 101. A regulating portion 102c is formed on the large-diameter central portion 101a side of the roller 101 of the cylindrical main body 102b. The tip height of the restricting portion 102 c is smaller than the outer diameter of the large-diameter central portion 101 a of the roller 101 so that the tip of the restricting portion 102 c does not come into contact with the transfer belt 100 while the transfer belt 100 is running.

  An endless ridge 100 a is disposed at the end of one surface of the transfer belt 100. When the transfer belt 100 is offset in the width direction while the transfer belt 100 is running, the restriction portion 102c of the meandering restriction member 102 comes into contact with the inner end of the protrusion 100a disposed on the transfer belt 100 and restricts the position of the transfer belt 100 in the width direction. To do. The side of the restricting portion 102 that comes into contact with the ridge 100a is an inclined surface in order to reduce friction caused by contact.

  A connecting portion 102f including an engaging convex portion 102d and an engaging concave portion 102e protruding toward the hollow portion 102a is formed at the end of the cylindrical main body 102b of the meandering restricting member 102.

  A bearing member 103 is disposed at the end of the small-diameter rotating shaft 101 b of the roller 101. The bearing member 103 is made of a metal such as iron or aluminum. The bearing member 103 is interposed between a hollow portion 103a having an inner diameter slightly larger than the outer diameter of the rotation shaft 101b for rotatably fitting to the rotation shaft 101b having a small diameter of the roller 101, and the rotation shaft 101b having a small diameter. A bearing housing portion 103b for arranging the bearing 104 is formed. The inner diameter of the bearing accommodating portion 103b is formed larger than the inner diameter of the hollow portion 103a.

  The bearing member 103 has a cylindrical main body 103 c that is inserted into an attachment hole formed in the frame 105 and a flange 103 d for fixing the bearing member 104 to the frame 105. The flange 103 d is larger than the inner diameter of the mounting hole formed in the frame 105, and the flange 103 d and the frame 104 are fixed by a fixing pin 106 to fix the bearing member 103 to the frame 105. A retaining ring 101 c is attached to the end of the small-diameter rotating shaft 101 b of the roller 101.

  The bearing member 103 is formed with a connecting portion 103g including an engaging convex portion 103e and an engaging concave portion 103f that protrude to the opposite side of the hollow portion 103a for connecting to the connecting portion 102f of the meandering restricting member 102.

  The connecting portion 103g of the bearing member 103 and the connecting portion 102f of the meandering restricting member 102 are connected to the connecting portion of the bearing member 103 by expanding the connecting portion 102 of the meandering restricting member 102 made of synthetic resin. As shown in FIG. 2, the engaging convex portion 102d formed on the meandering restricting member 102 engages with the engaging concave portion 103f formed on the bearing member 103, and the engaging convex portion 103e formed on the bearing member 103 is meandering restrictive. The meandering restricting member 102 is engaged with an engaging recess 102 e formed in the member 102, and is connected to a bearing member 103 fixed to the frame 105.

  The position of the restricting portion 102c of the meandering restricting member 102 is accurately positioned by the bearing member 103 fixed to the frame 104, and the deviation of the transfer belt 100 during travel is restricted by the contact between the restricting portion 102c and the protrusion 100a. .

  Further, as shown in FIG. 2, a gap 107 is formed at the connecting portion between the meandering restriction member 102 and the bearing member 103. The toner and carrier that have flowed out from the end of the transfer belt 100 flow into the connecting portion between the meandering restricting member 102 and the bearing member 103 from the gap 107 to reduce sliding friction, and the flowed out toner and carrier flow to the rotating shaft 101b. Can be prevented.

  FIG. 3 is a diagram illustrating a second embodiment of the transfer device in which the meandering regulating member 102 is disposed at an accurate position coaxial with the roller 101 and the meandering of the transfer belt 100 can be prevented.

  In the transfer apparatus according to the second embodiment, the bearing member 103 is formed integrally with the frame 105. If the frame 105 is made of aluminum or an aluminum alloy, a bearing member having a complicated shape can be easily integrally formed. By forming the bearing member 103 on the frame 105 by integral molding, the step of attaching the bearing member 103 to the frame 105 can be omitted. Since other configurations are the same as those of the first embodiment, the description thereof is omitted.

  FIG. 4 is a diagram illustrating a third embodiment of the transfer device in which the meandering restriction member 102 is disposed at an accurate position coaxial with the roller 101 to prevent the transfer belt 100 from meandering.

  In the transfer apparatus according to the third embodiment, a plurality of bearing members 103 and 103 ′ are fixed to the same frame 105, and meandering restriction members 102 and 102 ′ are connected to the bearing members 103 and 103 ′, respectively. Since the positions of the restricting portion restricting portions 102c and 102c ′ of the meander restricting members 102 and 102 ′ arranged coaxially with the plurality of rollers 101 and 101 ′ can be accurately positioned with reference to the same frame 105, one It is possible to efficiently obtain a greater regulating force than when regulating on the shaft.

  In the third embodiment shown in FIG. 4, the bearing member 103 is fixed to the frame 105 as a separate body from the frame 105. However, as in the second embodiment in which the bearing member 103 shown in FIG. In addition, a plurality of bearing members 103 and 103 ′ may be integrally formed on the same frame 105. Since other configurations are the same as those of the first and second embodiments, the description thereof is omitted.

  FIG. 5 is a diagram showing a fourth embodiment of the transfer device in which the meandering restricting member 102 is disposed at an accurate position coaxial with the roller 101 and the meandering of the transfer belt 100 can be prevented.

  In the transfer device according to the fourth embodiment, the meandering restriction member 102 is provided at both ends of the roller 101. Since the meandering while the transfer belt 100 is running is difficult to determine which side is offset due to the dimensional accuracy of the belt or the like, the meandering restricting members 102 are disposed on both sides of the roller 101, so that It can be used for both sides. The state shown in FIG. 5 shows a state in which the transfer belt 100 is shifted to the left side, and the regulation portion 102c of the right meandering regulating member 102 and the protrusion 100a are in contact to regulate meandering. Since other configurations are the same as those of the above-described embodiment, description thereof is omitted.

  As described above, according to the present invention, since the meandering restricting member is supported by the bearing member or the frame supported by the frame, the position of the restricting portion of the meandering restricting member can be accurately positioned with reference to the frame. The meandering of the transfer belt can be effectively regulated.

It is a figure which shows embodiment of this invention. It is a figure which shows embodiment of this invention. It is a figure which shows embodiment of this invention. It is a figure which shows embodiment of this invention. It is a figure which shows embodiment of this invention.

Explanation of symbols

  1: Image forming apparatus, 2Y, 2M, 2C, 2K: Photoconductor for each color, 5Y, 5M, 5C, 5K: Development apparatus for each color, 6Y, 6M, 6C, 6K: Photoconductor squeeze device, 7Y, 7M, 7C , 7K: primary transfer device for each color, 10: intermediate transfer belt, 11: belt drive roller (first backup roller), 12: driven roller (second backup roller), 16: secondary transfer device, 43: first second Next transfer roller, 44: Second secondary transfer roller, 45: Transfer belt cleaner, 46: Transfer material conveying belt, 100: Transfer belt, 101: Roller, 102: Meandering regulating member, 103: Bearing member, 104: Bearing, 105: Frame

Claims (8)

A transfer belt having a ridge,
A roller around which the transfer belt is wound;
A bearing member for supporting the roller;
A frame for supporting the bearing member;
A meandering restricting member that is coaxially arranged with the roller and supported by the bearing member or the frame;
A transfer device comprising: The meandering regulating member is
A cylindrical member rotatably fitted on the shaft of the roller;
A restricting portion that is formed at one axial end of the cylindrical member and that contacts the inner end of the ridge,
A connecting portion supported by the bearing member or the frame by positioning the position of the restricting portion formed at the other axial end of the cylindrical member;
The transfer device according to claim 1, comprising: The connecting portion has a first engaging convex portion and a first engaging concave portion, and the first engaging convex portion and the first engaging concave portion are formed on a second member formed at an end portion of the bearing member or the frame. The engagement according to claim 2 which engaged with the 2nd connecting part which has a joint concave part and the 2nd engagement convex part, and formed a crevice in an engagement part of said 1st engagement convex part and said 2nd engagement concave part. Transfer device. The transfer device according to claim 1, wherein the bearing member is formed on the frame by integral molding. The transfer device according to any one of claims 1 to 4, wherein the frame is formed by integrally forming a support member for supporting a plurality of bearing members or a plurality of bearing members. The transfer device according to claim 1, wherein the meandering restricting members are disposed at both ends of the roller in the axial direction. An image carrier for carrying a toner image;
A first transfer belt to which a toner image on the image carrier is transferred;
A second transfer belt for conveying a transfer material onto which a toner image on the first transfer belt is transferred;
A roller around which the first transfer belt is wound;
A bearing member for supporting the roller;
A frame for supporting the bearing member;
A meandering restricting member that is coaxially arranged with the roller and supported by the bearing member or the frame;
An image forming apparatus comprising: A roller around which the second transfer belt is wound;
A bearing member for supporting the roller;
A frame for supporting the bearing member;
A meandering regulating member that is coaxially arranged with the roller and supported by the bearing member or the frame;
The image forming apparatus according to claim 7, comprising:

Images