JP2015161941A - Belt device, and image forming apparatus including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the suppression of the occurrence of a gap between a belt member and contact members at a contact position.SOLUTION: Contact members, such as a cleaning blade 71 and an entrance seal member 72 are provided to contact a secondary transfer belt 61 within a contact range formed of a frist range (D) where the secondary transfer belt 61 and a secondary transfer roller 62 are in contact with each other and second ranges (D) extending from both ends of the first range to positions which are separated by the radial length of the secondary transfer roller 62.

Description

  The present invention relates to a belt device including an endless belt member that is stretched around a plurality of support rotating bodies, and an image forming apparatus such as a copying machine, a printer, and a facsimile including the belt device.

  As an image forming apparatus using an electrophotographic process, a color image forming apparatus is known in which a toner image of each color formed on a latent image carrier is primarily transferred to an intermediate transfer member and then secondarily transferred to a sheet material. ing. Secondary transfer devices in this type of image forming apparatus include a roller transfer method and a belt transfer method. The roller transfer method is a method in which secondary transfer is performed while a sheet material is sandwiched and conveyed between an intermediate transfer member and a transfer roller. On the other hand, the belt transfer method is a method in which secondary transfer is performed while a sheet material is sandwiched and conveyed between an endless conveyance belt stretched between support rollers of a secondary transfer device and an intermediate transfer member. In the belt transfer method, the sheet material is held and conveyed by at least one secondary transfer belt portion on the upstream side and the downstream side in the sheet material conveyance direction where the sheet material is sandwiched between the intermediate transfer member. For this reason, the sheet material can be held and imparted with conveying force not only at the location where the sheet material is sandwiched between the intermediate transfer member but also at the upstream side and downstream side in the sheet material conveying direction. Therefore, the belt transfer method is generally preferable to the roller transfer method with respect to the stable conveyance of the sheet material.

  In this belt transfer system, as in a general belt device, the secondary transfer belt moves toward one end in the belt width direction (belt shift), or the belt meandering is repeated such that the belt shift toward each end in the belt width direction is repeated. A phenomenon that occurs may occur. Near the belt (including belt meandering) is an assembly size tolerance of the structure constituting the secondary transfer device, for example, the parallelism of the rotation shafts of the plurality of support rollers that support the secondary transfer belt and the outer diameter of the rollers. This is caused by unevenness in tension, non-uniform tension due to a change in peripheral length of the secondary transfer belt itself, and the like. Due to these causes, the secondary transfer belt travels in a state of being displaced in the belt width direction without traveling in a straight line, so that the belt is displaced in the displaced direction.

Conventionally, various belt deviation regulating means have been proposed in order to keep the movement range of the belt in the width direction due to the belt deviation within a certain regulation range.
For example, in Patent Document 1, a tiltable steering roller is used as at least one of a plurality of support rollers for stretching a secondary transfer belt. An axis inclination type belt deviation regulating means for moving the belt in a direction to return the belt is disclosed. The belt deviation regulating means disclosed in Patent Document 1 is provided with a detection means for detecting the occurrence of belt deviation, and controls the amount of inclination of the steering roller based on the detection result of the detection means.

The inventors use a belt device that travels an endless belt member that is stretched by a plurality of support rollers in which at least one of a plurality of support rollers that stretch the endless belt member is a steering roller. The surface change was observed. As a result, it was confirmed that undulation was generated in an oblique direction with respect to the traveling direction of the belt member in the stretched portion of the belt member.
By the way, in the secondary transfer type image forming apparatus, a cleaning blade as a contact member that contacts the surface of the secondary transfer belt is a portion where the secondary transfer roller and the secondary transfer belt are in contact with each other. A cleaning mechanism that removes residual toner on the secondary transfer belt is employed. Further, on the upstream side in the belt traveling direction of the cleaning portion by the cleaning blade, as a contact member that contacts the surface of the secondary transfer belt so that the toner removed from the secondary transfer belt does not scatter in the apparatus. A seal member is disposed. When the waviness occurs at the contact position of the seal member, the end of the seal member is separated from the surface of the secondary transfer belt, and a gap is generated between the seal member and the surface of the secondary transfer belt at that location, There is a problem that the removed toner is scattered from the gap to the outside of the seal member. At the waviness occurrence location, the end of the cleaning blade or seal member is excessively pressed against the surface of the secondary transfer belt, the end of the cleaning blade or seal member is unnecessarily worn, and the cleaning performance and sealing performance are insufficient. There was also a problem of becoming. The inventors observed changes in the surface of the secondary transfer belt through an experiment using a belt device that does not include a steering roller, and confirmed undulations in the stretched portion of the belt member. The above problem is not limited to the case of the belt device provided with the steering roller, but may also occur in the case of the belt device not provided with the steering roller.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a belt device capable of suppressing the generation of a gap at a contact portion between the contact member and the belt member, and an image forming apparatus including the belt device. Is to provide.

  In order to achieve the above object, the invention of claim 1 is a belt device comprising an endless belt member that runs while being stretched around a plurality of support rotating bodies, and an abutting member that abuts against the surface of the belt member. The contact member includes a first range in which the belt member and the support rotating body are in contact with each other in a running direction of the belt member, and a radius of the support rotating body from both sides of the first range. The belt member is provided so as to be in contact within a contact range formed by a second range up to a portion separated by a length.

  According to the present invention, it is possible to obtain a unique effect that it is possible to suppress the generation of a gap at a contact portion between the contact member and the belt member.

1 is a schematic configuration diagram illustrating a printer according to an embodiment. It is a perspective view of a secondary transfer device. It is a schematic diagram explaining the structure of the secondary transfer apparatus seen from the axial direction. It is a schematic diagram explaining the structure of the cleaning apparatus seen from the axial direction. It is a schematic diagram explaining the modification of the secondary transfer apparatus seen from the axial direction.

Hereinafter, an embodiment in which the present invention is applied to a printer which is an electrophotographic image forming apparatus will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram illustrating a printer according to the present embodiment.
The printer is provided with four photoconductors 1a, 1b, 1c, and 1d arranged in the main body casing. Different color toner images are formed on the respective photoreceptors. Specifically, a black toner image, a magenta toner image, a cyan toner image, and a yellow toner image are formed on these photoreceptors 1a, 1b, 1c, and 1d, respectively. Note that each of the photoreceptors 1a, 1b, 1c, and 1d in the present embodiment is formed in a drum shape, but an endless belt-like photoreceptor that is wound around a plurality of rollers and driven to rotate can also be used.

  An intermediate transfer belt 51, which is an endless belt-like member, is disposed as an intermediate transfer member that is an image carrier, facing the four photosensitive members 1a, 1b, 1c, and 1d. The outer peripheral surfaces of the photoreceptors 1a, 1b, 1c, and 1d are in contact with the outer peripheral surface of the intermediate transfer belt 51, respectively. The intermediate transfer belt 51 according to the present embodiment is wound and stretched around a support roller (support rotary body) such as a tension roller 52, a drive roller 53, a repulsive roller 54, and an entrance roller 55. A driving roller 53 that is one of these support rollers is rotationally driven by a driving source (not shown), and the intermediate transfer belt 51 travels in the direction of arrow A in FIG.

  The intermediate transfer belt 51 may have a multilayer structure or a single layer structure. When the belt is composed of a multilayer structure, for example, a base layer is formed of a less stretched fluororesin, PVDF sheet, or polyimide resin, and the belt outer peripheral surface is composed of a smooth coat layer such as a fluororesin. preferable. On the other hand, when a belt having a single layer structure is used, a material such as PVDF, PC, or polyimide is preferably used.

  The configuration and operation for forming each color toner image on each photoconductor 1a, 1b, 1c, 1d and the configuration and operation for primary transfer of each color toner image onto the intermediate transfer belt 51 are substantially the same and formed. Only the color of each color toner image is different. Therefore, hereinafter, a configuration and operation for forming a black toner image on the black photoconductor 1a and primarily transferring the toner image onto the intermediate transfer belt 51 will be described, and description of other colors will be omitted.

  The black photoconductor 1a is driven to rotate counterclockwise in FIG. The surface potential of the photoconductor 1a is initialized by irradiating the outer peripheral surface of the photoconductor 1a with light from a static eliminator (not shown). The initialized outer peripheral surface of the photoconductor is uniformly charged to a predetermined polarity (in this embodiment, a negative polarity) by the charging device 8a. The photosensitive member outer peripheral surface thus charged is irradiated with a light-modulated laser beam L emitted from an exposure device (not shown), whereby an electrostatic latent image is formed on the outer peripheral surface of the photosensitive member 1a. . In the present embodiment, the exposure apparatus that emits the laser beam L is configured by a laser writing apparatus. However, for example, an exposure apparatus having an LED array and an image forming unit may be used. The electrostatic latent image formed on the photoconductor 1a is visualized as a black toner image when passing through a developing area facing the developing device 10a.

  On the inner peripheral surface side of the intermediate transfer belt 51, a primary transfer roller 11a is disposed at a position facing the photoreceptor 1a. When the primary transfer roller 11 a contacts the inner peripheral surface of the intermediate transfer belt 51, an appropriate primary transfer nip is ensured between the photoreceptor 1 a and the intermediate transfer belt 51. The primary transfer roller 11a is applied with a primary transfer voltage having a polarity opposite to the toner charging polarity of the toner image formed on the photoreceptor 1a (plus polarity in the present embodiment). As a result, a primary transfer electric field is formed between the photoreceptor 1a and the intermediate transfer belt 51, and the toner image on the photoreceptor 1a is statically transferred onto the intermediate transfer belt 51 that is driven to rotate in synchronization with the photoreceptor 1a. Electrically primary transferred. The transfer residual toner adhering to the outer peripheral surface of the photoconductor 1a after the toner image is primarily transferred to the intermediate transfer belt 51 is removed by the cleaning device 12a, and the outer peripheral surface of the photoconductor 1a is cleaned.

  In the full color mode using all four color toner images, magenta toner images, cyan toner images, and yellow toner images are similarly formed on the photoconductors 1b, 1c, and 1d of other colors. These color toner images are sequentially primary-transferred so as to be superimposed on the black toner image primarily transferred onto the intermediate transfer belt 51.

  On the other hand, in the black monochromatic mode, the primary transfer rollers 11b, 11c, and 11d are separated from the photoreceptors 1b, 1c, and 1d by a contact / separation mechanism (not shown) to thereby provide the photoreceptors 1b, 1c, magenta, cyan, and yellow. 1 d is separated from the intermediate transfer belt 51. Only the black toner image is primarily transferred to the intermediate transfer belt 51 while only the black photosensitive member 1 a is in contact with the intermediate transfer belt 51.

  As shown in FIG. 1, a paper feeding device 14 is disposed at the lower part of the printer body. The sheet feeding device 14 feeds the transfer sheet P as a sheet material in the direction of arrow B in FIG. The transferred transfer paper P is subjected to a contact between the intermediate transfer belt 51 wound around the repulsive roller 54 at a predetermined timing by the registration roller pair 16 and the secondary transfer belt 61 disposed opposite thereto. It is fed to the secondary transfer nip that is in contact. At this time, a predetermined secondary transfer voltage is applied to the repulsive roller 54, whereby the toner image on the intermediate transfer belt 51 is secondarily transferred to the transfer paper P.

  A secondary transfer belt 61 as a first conveying belt is stretched between a secondary transfer roller 62 and a separation roller 63 that is a separation rotating body. In the present embodiment, the secondary transfer roller 62 is driven to rotate as a driving roller, so that the secondary transfer belt 61 travels in the direction of arrow C in FIG. The transfer paper P onto which the toner image has been secondarily transferred is conveyed as the secondary transfer belt 61 travels while being electrostatically attracted to the outer peripheral surface of the secondary transfer belt 61. Then, the transfer paper P is separated from the outer peripheral surface of the secondary transfer belt 61 by the curvature of the portion of the secondary transfer belt 61 wound around the separation roller 63. The secondary transfer belt 61 is further conveyed downstream in the transfer paper conveyance direction by a conveyance belt 17 as a second conveyance belt disposed on the downstream side in the transfer paper conveyance direction. The conveyor belt 17 is stretched between an inlet roller 17A as a driving roller as an inlet rotator and a driven roller 17B as a driven rotator. When the transfer paper P passes through the fixing device 18, the toner image on the transfer paper P is fixed to the transfer paper P by the action of heat and pressure. The transfer paper P that has passed through the fixing device 18 is discharged out of the apparatus through a pair of paper discharge rollers 19 provided in the paper discharge unit.

  Further, the transfer residual toner adhering to the intermediate transfer belt 51 after the toner image is secondarily transferred is removed by the belt cleaning device 20. In the belt cleaning device 20 according to the present embodiment, a blade-shaped cleaning blade 21 made of urethane or the like is used, and the cleaning blade 21 is brought into contact with the traveling direction of the intermediate transfer belt 51 from the counter direction. . Various types of belt cleaning device 20 can be used as appropriate, and for example, the cleaning device may be an electrostatic type.

  FIG. 2 is a perspective view of the secondary transfer device 60. FIG. 3 is a schematic view seen from the axial direction. As shown in FIG. 2, the secondary transfer belt 61 receives a biasing force in a direction in which the separation roller 63 separates from the secondary transfer roller 62 due to the biasing force of the tension spring 67 of the rotating shaft support arm 64. For this reason, it is stretched with a predetermined tension. The frame 68 is provided with a notch (not shown) as a second holding part for detachably holding a bearing member (not shown) attached to the end of the rotary shaft 62a of the secondary transfer roller 62. Yes. Further, the end of the rotating shaft 63a of the separation roller 63 is detachably held by the frame 68. A bearing member (not shown) provided at each end of the rotating shaft of the secondary transfer roller 62 and a shaft inclined member (not shown) provided at each end of the rotating shaft of the separation roller 63 are held by the frame 68, respectively. Is done.

  As shown in FIG. 3, a cleaning device 70 is disposed below the secondary transfer device 60. The cleaning blade 71 is in contact with the traveling direction indicated by the arrow A in FIG. 3 of the secondary transfer belt 61 from the counter direction. Thereby, the transfer residual toner on the secondary transfer belt 61 is removed. The removed toner falls by its own weight. In order to prevent the toner dropped from the secondary transfer belt 61 from scattering, an inlet seal member 72 as a seal member is disposed upstream from the contact portion between the secondary transfer belt 61 and the secondary transfer roller 62 in the traveling direction. The inlet seal member 72 bites into the surface of the secondary transfer belt 61, and the bite amount is set so that no gap is generated between the secondary transfer belt 61 and the inlet seal member 72. Yes.

The inventors conducted an experiment to observe the surface of the secondary transfer belt 61 when the secondary transfer device 60 was used. As a result of the experiment, as shown in FIG. 2, it was confirmed that the corrugation 101 was generated obliquely with respect to the traveling direction of the secondary transfer belt 61. When this occurs at the contact portion 72 a of the inlet seal member 72 with the secondary transfer belt 61, a portion where the end of the inlet seal member 72 is separated from the surface of the secondary transfer belt 61 occurs. At that location, a gap is generated between the surface of the secondary transfer belt 61 and the toner leaks from the gap to the outside of the inlet seal member 72 and is scattered in the apparatus. As a result of observing the phenomenon at the time of the occurrence of undulations, the predetermined interval (D ₁ ) of the contact portion between the secondary transfer belt 61 and the secondary transfer roller 62 and the predetermined interval (D ₂ ) separated from both sides of the contact portion are obtained. It was confirmed that the next transfer belt 61 was not wavy. In addition, when a plurality of secondary transfer rollers 62 with increased or decreased radii are used, the predetermined section (D ₂ ) where no undulation is generated changes according to the radius, and the predetermined section ( It was confirmed that D ₂ ) was substantially the same as the radius of the secondary transfer roller 62.

In the present embodiment, as shown in FIG. 3, a predetermined section (D ₁ ) of the contact portion between the secondary transfer belt 61 and the secondary transfer roller 62, and a predetermined section (D ₁ ) upstream from the contact portion in the traveling direction. ₂ ), and the contact position of the inlet seal member 72 is disposed within the contact range of the predetermined section (D ₂ ) on the upstream side in the traveling direction from the contact location. Further, the length of the predetermined section (D ₂ ) is defined as the radius of the secondary transfer roller 62. As a result, the generation of a gap between the surface of the secondary transfer belt 61 and the inlet seal member 72 due to the corrugation of the secondary transfer belt can be suppressed, and the waste toner leaks from the cleaning device 70 and is scattered in the machine. Can be suppressed.

Next, the configuration of the belt cleaning device 20 in FIG. 1 will be described.
FIG. 4 is a schematic diagram illustrating the configuration of the belt cleaning device viewed from the axial direction. As shown in FIG. 4, the intermediate transfer belt 51 is disposed on the downstream side of the secondary transfer portion, and a cleaning blade 21 for cleaning the intermediate transfer belt 51 is brought into contact with the intermediate transfer belt 51, so It is the structure which makes it fall. Here, an inlet seal member 23 is disposed on the upstream side of the cleaning blade 21, and the tip portion is brought into contact with the intermediate transfer belt 51 to suppress toner scattering to the upstream portion. Even when the intermediate transfer belt is supported by a plurality of support rollers, the intermediate transfer belt 51 is wavy at the stretched portion of the support roller. Also in the belt cleaning device 20, the cleaning blade 21 and the inlet seal member 23 are provided so that the contact portion of the cleaning blade 21 and the inlet seal member 23 is located in a section where no waviness occurs as described above. Thereby, it is possible to suppress the waste toner from leaking from the belt cleaning device 20 and scattering into the machine.

(Modification)
Next, a modification of the secondary transfer device in the above embodiment (hereinafter, this modification is referred to as “modification”) will be described.
FIG. 5 is a diagram illustrating a modification of the secondary transfer device.
Both the intermediate transfer member in the image forming apparatus and the secondary transfer belt in the secondary transfer apparatus apply a solid lubricant to the surface of the belt in order to suppress the frictional resistance of the belt. As shown in FIG. 4, in the lubricant application device 200, the solid lubricant 201 is transferred to the application roller 202, the application roller 202 is brought into contact with the belt surface of the secondary transfer belt 61, and the solid lubricant is applied to the belt surface. 201 is applied. The solid lubricant 201 is pressed against the roller surface of the application roller 202 with a predetermined pressure by a pressing means 203 such as a solenoid. In addition, the contact position of the inlet seal member 72 is arranged in a range indicated by a broken line in FIG. A thickness adjusting blade (not shown) that adjusts the solid lubricant 201 remaining on the secondary transfer belt 61 to a target thickness by scraping off an unnecessary thickness is provided for the secondary transfer belt 61, the application roller 202, and the like. Is disposed on the downstream side in the traveling direction of the secondary transfer belt 61. The contact position of the inlet seal member 72 is disposed in the vicinity of the application roller 202, and the application roller 202 is also in contact with the secondary transfer belt and the blade is in the range indicated by the broken line in FIG. Thereby, the application amount of the solid lubricant 201 and the contact amount of the blade can be set to desired amounts, and the solid lubricant 201 can be applied and removed stably.

  In this embodiment, the belt device is applied to the secondary transfer device 60. However, the belt device may be similarly applied to a belt device using other endless belt members such as the intermediate transfer belt 51. Can do. Further, in this embodiment, the belt device includes the belt shift regulating means, but the present invention can be similarly applied to a belt device that does not include the belt shift regulating means. Further, the present invention is not limited to the plate material of the cleaning blade and the seal member, and can be similarly applied to an apparatus using a rotating body or a brush.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
A belt member such as an endless secondary transfer belt 61 that runs on a plurality of support rotating bodies such as the secondary transfer roller 62 and the separation roller 63, and a cleaning blade 71 that contacts the surface of the belt member and an inlet seal In a belt device such as the secondary transfer device 60 including a contact member such as the member 72, the contact member of the cleaning blade 71 and the inlet seal member 72 is secondary in the traveling direction of the belt member of the secondary transfer belt 61. A first range (D ₁ ) in which the transfer belt 61 and the secondary transfer roller 62 are in contact with each other, and a second range from both sides of the first range to a location separated by the length of the radius of the secondary transfer roller 62. It is provided so as to come into contact with the secondary transfer belt 61 within the contact range formed by the range (D ₂ ).
According to this, as described in the above embodiment, the surface of the surface of the belt member is used by using the belt device that stretches the endless belt member by the two supporting rotating bodies of the supporting roller and the tilting roller and moves the endlessly. Changes were observed. As a result, in the contact range formed by the first range where the belt member and the support roller or the tilting roller are in contact with each other, and the second range corresponding to the radius of the support rotating body from both sides of the first range, No change in the surface of the belt member was observed, and a wavy phenomenon was observed in a range other than the contact range. In the present invention, the contact member is provided so as to contact the belt member within the contact range. Thereby, the state which contact | abutted on the surface of the belt member of a contact member is maintained. Therefore, generation | occurrence | production of the clearance gap in the contact location with the belt member of a contact member can be suppressed.
(Aspect B)
In (Aspect A), at least one of the supporting rotating bodies is tilted. According to this, as described in the above embodiment, even in the secondary transfer device 60 using the separation roller 63 as the tilting roller, no undulation occurred on the surface of the secondary transfer belt 61 in the contact range. The cleaning blade 71 and the inlet seal member 72 are provided so as to contact the secondary transfer belt 61 within the contact range. Accordingly, the cleaning blade 71 and the inlet seal member 72 and the secondary transfer belt are avoided while avoiding the contact portion of the cleaning blade 71 and the inlet seal member 72 with the secondary transfer belt 61 from the wavy portion on the secondary transfer belt 61. It is possible to suppress the generation of a gap at the contact point with 61.
(Aspect C)
In (Aspect A) or (Aspect B), the contact member is a cleaning blade 71 that removes the adhering matter adhering to the surface of the belt member. According to this, as described in the above embodiment, the contact amount of the cleaning blade 71 can be set to a desired amount, and the surface of the secondary transfer belt 61 can be stably cleaned.
(Aspect D)
In any one of (Aspect A) to (Aspect C), the abutting member is an inlet seal member that abuts on the surface of the belt member on the upstream side in the running direction of the belt member from the abutting portion of the cleaning blade 71 with the belt member. 72 or the like, and closes the upstream side from the contact point of the cleaning blade 71. According to this, as described in the above embodiment, the generation of a gap between the surface of the secondary transfer belt 61 and the inlet seal member 72 due to the undulation phenomenon of the secondary transfer belt 61 can be suppressed, and the removed deposits are removed. Leakage to the outside of the inlet seal member 72 can be suppressed.
(Aspect E)
In any one of (Aspect A) to (Aspect D), an application unit such as an application roller 202 that applies a lubricant such as a solid lubricant 201 is provided on the surface of the belt member, and the application position of the application unit abuts. Is in range. According to this, as described in the above embodiment, the application amount of the solid lubricant 201 can be set to a desired amount, and the application of the solid lubricant 201 can be performed stably.
(Aspect F)
In an image forming apparatus that forms an image on the sheet material by using a belt device including an endless belt member that supports an image or a sheet material on which an image is recorded on an outer peripheral surface, The belt device according to any one of Aspects A) to (Aspect B) is used. According to this, as described in the above embodiment, it is possible to realize an image forming apparatus in which image disturbance and jamming are suppressed.
(Aspect G)
In (Aspect F), primary transfer rollers 11a, 11b, 11c, and 11d that primarily transfer an image formed on a latent image carrier such as the photoreceptors 1a, 1b, 1c, and 1d to an intermediate transfer member such as the intermediate transfer belt 51. Primary transfer means and the like, and secondary transfer means such as a secondary transfer device 60 that secondary-transfers the image primarily transferred onto the intermediate transfer member onto the sheet material P. The secondary transfer means The image on the intermediate transfer member is secondarily transferred onto the sheet material carried and conveyed on the outer peripheral surface of the transfer belt 61. According to this, as described in the above embodiment, it is possible to suppress image disturbance and jamming in an image forming apparatus that employs an intermediate transfer method.

20 Belt Cleaning Device 60 Secondary Transfer Device 61 Secondary Transfer Belt 62 Secondary Transfer Roller 62a Rotating Shaft 63 Separating Roller 64 Rotating Shaft Support Arm 67 Tension Spring 68 Frame 71 Cleaning Blade 72 Entrance Seal Member 72a Abutting Location 101 Corrugation 200 Lubrication Agent Application Device 201 Solid Lubricant 202 Application Roller

JP 2012-103286 A

The inventors use a belt device that travels an endless belt member that is stretched by a plurality of support rollers in which at least one of a plurality of support rollers that stretch the endless belt member is a steering roller. The surface change was observed. As a result, it was confirmed that undulation was generated in an oblique direction with respect to the traveling direction of the belt member in the stretched portion of the belt member.
Incidentally, in the image forming apparatus of the secondary transfer equation, a blade for being in contact with the surface of the secondary transfer belt torque cleaning, opposite the portion where the secondary transfer roller and the secondary transfer belt are in contact with each other A cleaning mechanism that abuts the position and removes transfer residual toner on the secondary transfer belt is employed. Further, on the upstream side of the belt travel direction of the cleaning position by the blade for cleaning, so that the toner removed from the secondary transfer belt is not scattered in the apparatus, in contact with the surface of the secondary transfer belt Resid Lumpur member Has been placed. When the waviness occurs at the contact position of the seal member, the tip of the seal member is separated from the surface of the secondary transfer belt, and a gap is generated between the seal member and the surface of the secondary transfer belt at that location, and is removed. There is a problem that the toner that has been scattered scatters from the gap to the outside of the seal member. In the undulating occurrence place, the tip of the sheet seal member is pressed excessively to the surface of the secondary transfer belt, and unnecessarily wear the tip of the sheet seal member, a problem that sheet Lumpur property becomes insufficient There was also. The inventors observed changes in the surface of the secondary transfer belt through an experiment using a belt device that does not include a steering roller, and confirmed undulations in the stretched portion of the belt member. The above problem is not limited to the case of the belt device provided with the steering roller, but may also occur in the case of the belt device not provided with the steering roller.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a belt device capable of suppressing generation of a gap at a contact portion between a seal member and a belt member, and an image forming apparatus including the belt device. Is to provide.

To achieve the above object, the invention of claim 1 is attached an endless belt member which runs stretched over a plurality of supporting rotating bodies, to the surface to contact with the surface of the belt member A cleaning blade that removes deposits and a contact portion of the cleaning blade that contacts the surface of the belt member upstream of the contact portion of the cleaning blade with the surface of the belt member in the belt traveling direction of the belt member and the belt device and a sealing member for closing the upstream side, the sealing member is in the running direction of the belt member, the area wrapped around said belt member is wound around the outer peripheral surface of the supporting rotator from the wound area the belt portion is but Ru region and Tona only the radius of the length of said supporting rotator which is formed to a point spaced from both ends of the winding region contact area It is characterized in that provided so as to contact the.

According to the present invention, it is possible to obtain a specific effect that it is possible to suppress the generation of a gap at a contact portion between the seal member and the belt member.

As shown in FIG. 3, a cleaning device 70 is disposed below the secondary transfer device 60. The cleaning blade 71 is in contact with the traveling direction indicated by the arrow A in FIG. 3 of the secondary transfer belt 61 from the counter direction. Thereby, the transfer residual toner of the secondary transfer belt 61 is removed. The removed toner falls by its own weight. In order to prevent the toner dropped from the secondary transfer belt 61 from scattering, an inlet seal member 72 as a seal member is disposed upstream from the contact portion between the secondary transfer belt 61 and the secondary transfer roller 62 in the traveling direction. The leading end of the inlet seal member 72 bites into the surface of the secondary transfer belt 61, and the biting amount causes a gap between the surface of the secondary transfer belt 61 and the leading end of the inlet seal member 72. It is set not to.

The inventors conducted an experiment to observe the surface of the secondary transfer belt 61 when the secondary transfer device 60 was used. As a result of the experiment, as shown in FIG. 2, it was confirmed that the corrugation 101 was generated obliquely with respect to the traveling direction of the secondary transfer belt 61. If generated in Tose' plants the secondary transfer belt 61 of the inlet seal member 72, portions of the tip of the inlet seal member 72 is away from the surface of the secondary transfer belt 61 occurs. At that location, a gap is generated between the front end of the inlet seal member 72 and the surface of the secondary transfer belt 61, and toner leaks out of the inlet seal member 72 from the gap and is scattered in the apparatus. Predetermined result of observation of the phenomenon during occurrence waviness, away from both ends of the secondary area transfer belt 61 is wound around the outer peripheral surface of the secondary transfer roller 62, the area wrapped predetermined interval (D ₁₎ and the so-called winding region It was confirmed that no waviness occurred in the secondary transfer belt 61 in the section (D ₂ ). In addition, when a plurality of secondary transfer rollers 62 with increased and decreased radii are used, the predetermined section (D ₂ ) where no undulation is generated changes according to the radius, and the predetermined section ( It was confirmed that D ₂ ) was substantially the same as the radius of the secondary transfer roller 62.

In the present embodiment, as shown in FIG. 3, the secondary transfer belt 61 and the secondary transfer roller 62 and the winding region of a predetermined interval (D _1), upstream in the traveling direction from the winding region side of the predetermined section (D ₂₎ and wound in abutting range of the predetermined interval (D ₂₎ of the lower flow side in the traveling direction from the area, place the inlet seal member 71 so that the tip of the inlet seal member 72 abuts against the surface of the secondary transfer belt 61 To do. Further, the length of the predetermined section (D ₂ ) is defined as the radius of the secondary transfer roller 62. As a result, the generation of a gap between the surface of the secondary transfer belt 61 and the inlet seal member 72 due to the corrugation of the secondary transfer belt can be suppressed, and the waste toner leaks from the cleaning device 70 and is scattered in the machine. Can be suppressed.

Next, the configuration of the belt cleaning device 20 in FIG. 1 will be described.
FIG. 4 is a schematic diagram illustrating the configuration of the belt cleaning device viewed from the axial direction. As shown in FIG. 4, the intermediate transfer belt 51 is disposed on the downstream side of the secondary transfer portion, and a cleaning blade 21 for cleaning the intermediate transfer belt 51 is brought into contact with the intermediate transfer belt 51, so It is the structure which makes it fall. Here, an inlet seal member 23 is disposed on the upstream side of the cleaning blade 21, and the tip of the inlet seal member 23 is brought into contact with the surface of the intermediate transfer belt 51 to suppress toner scattering to the upstream portion. Even when the intermediate transfer belt 51 is supported by a plurality of support rollers, the intermediate transfer belt 51 is wavy at the stretched portion of the support rollers. Also in the belt cleaning device 20, contact portion of the input mouth sealing member 23 is provided with inlet mouth sealing member 23 so as to be positioned in the segment with no occurrence of waving in the same manner described above. Thereby, it is possible to suppress the waste toner from leaking from the belt cleaning device 20 and scattering into the machine.

(Modification)
Next, a modification of the secondary transfer device in the above embodiment (hereinafter, this modification is referred to as “modification”) will be described.
FIG. 5 is a diagram illustrating a modification of the secondary transfer device.
Both the intermediate transfer member in the image forming apparatus and the secondary transfer belt in the secondary transfer apparatus apply a solid lubricant to the belt surface in order to suppress the frictional resistance of the belt. As shown in FIG. 5 , in the lubricant application device 200, the solid lubricant 201 is transferred to the application roller 202, the application roller 202 is brought into contact with the belt surface of the secondary transfer belt 61, and the solid lubricant is applied to the belt surface. 201 is applied. The solid lubricant 201 is pressed against the roller surface of the application roller 202 with a predetermined pressure by a pressing means 203 such as a solenoid. Incidentally, placing the abutting position of the inlet seal member 72 to the broken line range in FIG. A thickness adjusting blade (not shown) that adjusts the solid lubricant 201 remaining on the secondary transfer belt 61 to a target thickness by scraping off an unnecessary thickness is provided for the secondary transfer belt 61, the application roller 202, and the like. Is disposed on the downstream side in the traveling direction of the secondary transfer belt 61. With placing the abutting position of the inlet seal member 72 in the vicinity of the coating roller 202, also contact the abutment or blade the secondary transfer belt of the applying roller 202, in a range of the broken line in FIG. Thereby, the application amount of the solid lubricant 201 and the contact amount of the blade can be set to desired amounts, and the solid lubricant 201 can be applied and removed stably.

In this embodiment, the belt device is applied to the secondary transfer device 60. However, the belt device may be similarly applied to a belt device using other endless belt members such as the intermediate transfer belt 51. Can do. Further, in this embodiment, the belt device includes the belt shift regulating means, but the present invention can be similarly applied to a belt device that does not include the belt shift regulating means. Furthermore, in the present embodiment , a plate material is used for the seal member. However , the present invention is not limited to this . The present invention can be similarly applied to an example in which a rotating body is used as the seal member instead of the plate material .

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
An endless second transfer belt 61 and the like of the belt member running is stretched in a plurality of supporting rotating bodies, such as the secondary transfer roller 62 and the separation roller 63, and adheres to the contact surface to the surface of the belt member The surface of the secondary transfer belt 61 contacts the surface of the secondary transfer belt 61 on the upstream side in the belt running direction of the secondary transfer belt 61 from the contact point between the cleaning blade 71 that removes adhering matter and the surface of the secondary transfer belt 61 of the cleaning blade 71. the belt device, such as a secondary transfer device 60 and a seal member such as an inlet seal member 72 that closes the upstream side from the contact portion of the cleaning blade 71 in contact, enter the mouth sealing member 7 2, the secondary transfer belt 61 in the running direction of the belt member, the secondary transfer belt 61 is secondary and the region winding which is wound around the outer peripheral surface of the transfer roller 62, the two-winding region is formed transfer row Ru region and Tona to point away from the ends of the radius of the region wrapped by a length La 62 in contact region provided so as to contact the secondary transfer belt 61.
According to this, as described in the above embodiment, the surface of the surface of the belt member is used by using the belt device that stretches the endless belt member by the two supporting rotating bodies of the supporting roller and the tilting roller and moves the endlessly. Changes were observed. As a result, the wound area, the contact area formed by the radius of the region of the supporting rotator from both ends of the wound area, changes in the surface of the belt member is not observed in the range of non-contact range, A wavy phenomenon was observed. In the present invention, the inlet seal member 72 is provided so as to contact the belt member within the contact range. Thereby, the state which contact | abutted on the surface of the belt member of the inlet seal member 72 is maintained. Therefore, generation | occurrence | production of the clearance gap in the contact location with the belt member of the inlet seal member 72 can be suppressed.
(Aspect B)
In (Aspect A), at least one of the supporting rotating bodies is tilted. According to this, as described in the above embodiment, even in the secondary transfer device 60 using the separation roller 63 as the tilting roller, no undulation occurred on the surface of the secondary transfer belt 61 in the contact range . ON mouth sealing member 72 is provided so as to contact the secondary transfer belt 61 of the contact region. Thus, while avoiding contact portion between the secondary transfer belt 61 of the inlet mouth sealing member 72 from waving occurrence location on the secondary transfer belt 61, contact portion between the inlet mouth sealing member 72 and the secondary transfer belt 61 It is possible to suppress the occurrence of gaps in
(Aspect C )
Oite to (embodiment A) or (aspect B), comprising a coating means such as coating roller 202 for applying the lubricant of the solid lubricant 201 or the like on the surface of the belt member, the coating position of the coating means, the abutment range Is in. According to this, as described in the above embodiment, the application amount of the solid lubricant 201 can be set to a desired amount, and the application of the solid lubricant 201 can be performed stably.
(Aspect D )
In an image forming apparatus that forms an image on the sheet material by using a belt device including an endless belt member that supports an image or a sheet material on which an image is recorded on an outer peripheral surface, A belt device according to any one of Aspects A) to (Aspect C ) is used. According to this, as described in the above embodiment, it is possible to realize an image forming apparatus in which image disturbance and jamming are suppressed.
(Aspect E )
In (Aspect D ), primary transfer rollers 11a, 11b, 11c, and 11d that primarily transfer an image formed on a latent image carrier such as the photoreceptors 1a, 1b, 1c, and 1d to an intermediate transfer member such as the intermediate transfer belt 51. Primary transfer means and the like, and secondary transfer means such as a secondary transfer device 60 that secondary-transfers the image primarily transferred onto the intermediate transfer member onto the sheet material P. The secondary transfer means The image on the intermediate transfer member is secondarily transferred onto the sheet material carried and conveyed on the outer peripheral surface of the transfer belt 61. According to this, as described in the above embodiment, it is possible to suppress image disturbance and jamming in an image forming apparatus that employs an intermediate transfer method.

20 Belt cleaning device 60 Secondary transfer device 61 Secondary transfer belt 62 Secondary transfer roller 62a Rotating shaft 63 Separating roller
63a rotating shaft 64 rotary shaft support arm 67 tension spring 68 frame 71 a cleaning blade 72 entrance seal member
1 01 Wave 200 Lubricant coating device 201 Solid lubricant 202 Coating roller

Claims (7)

In a belt device comprising: an endless belt member that runs while being stretched around a plurality of support rotating bodies; and an abutting member that abuts on the surface of the belt member.
The contact member includes a first range in which the belt member and the support rotating body are in contact with each other in a running direction of the belt member, and a radius length of the support rotating body from both sides of the first range. A belt device characterized by being provided so as to abut on the belt member within a contact range formed by a second range up to a location separated by a distance. The belt device according to claim 1, wherein
A belt device characterized by tilting at least one of the support rotating bodies. The belt device according to claim 1 or 2,
The belt device according to claim 1, wherein the contact member is a cleaning blade that removes deposits adhered to the surface of the belt member. The belt device according to any one of claims 1 to 3,
The contact member is a seal member that contacts the surface of the belt member on the upstream side in the running direction of the belt member from the contact position of the cleaning blade with the belt member, and from the contact position of the cleaning blade A belt device that closes the upstream side. In the belt apparatus in any one of Claims 1-4,
A belt device comprising: an application unit that applies a lubricant to a surface of the belt member, and an application position of the application unit is within the contact range. In an image forming apparatus that forms an image on the sheet material using a belt device including an endless belt member that carries an image or a sheet material on which an image is recorded on an outer peripheral surface.
An image forming apparatus using the belt device according to claim 1 as the belt device. The image forming apparatus according to claim 6.
Primary transfer means for primarily transferring an image formed on the latent image carrier to an intermediate transfer member;
Secondary transfer means for secondary transfer of the image primarily transferred onto the intermediate transfer member to the sheet material;
The image forming apparatus, wherein the secondary transfer unit secondarily transfers an image on the intermediate transfer member onto a sheet material carried on an outer peripheral surface of the belt member.

Images