JP2008070706A - Belt device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely prevent a foreign matter stored in a storing part from being leaked and to achieve a stable sealing function even when a belt is meandered by supporting the end of the belt from both sides in a tight-contact state by a sealing member formed so that its width may be larger than a meandering distance in the lateral direction of the belt and a support roller formed to be longer than length obtained by adding the meandering distance in the lateral direction of the belt to the width of the belt. <P>SOLUTION: The belt device has: a plurality of rollers; the belt tensioned and laid on the plurality of rollers; a cleaning member coming into contact with the belt and removing the foreign matter adhering to the belt; the support roller opposed to the cleaning member while putting the belt in between and made longer than the length obtained by adding the meandering distance in the lateral direction of the belt to the width of the belt; the storing part for storing the foreign matter removed by the cleaning member; and the sealing member coming into contact with the belt and the support roller and preventing the foreign matter stored in the storing part from being leaked. The length of the sealing member in the lateral direction of the belt is longer than the meandering distance. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

  2. Description of the Related Art Conventionally, in image forming apparatuses such as color copiers and color printers, image forming units corresponding to yellow, magenta, cyan, and black colors are arranged in tandem along a paper conveyance path. In this case, each image forming unit includes a photosensitive drum, and forms yellow, magenta, cyan, and black toner images on the respective photosensitive drums, and each color toner image is transported on a transport path. A color image is formed by sequentially transferring to a sheet of paper.

In such an image forming apparatus, a belt apparatus using an endless belt is used to convey a sheet or a toner image. The belt device is provided with a cleaning blade made of urethane rubber or the like in order to remove foreign matters such as dust, paper powder, and toner floating on the image forming apparatus attached to or transferred to the endless belt. The endless belt is cleaned by pressing against the belt (for example, see Patent Document 1). The foreign matter removed from the endless belt by the cleaning blade is stored in a foreign matter collection container provided below the cleaning blade.
JP 2002-23518 A

  However, in the conventional image forming apparatus, the foreign matter collection container has an opening for taking in the foreign matter removed by the cleaning blade, and the foreign matter is collected from the gap between the opening and the belt. Foreign matter stored in the container may leak out. As a method for preventing such leakage of foreign matter, it is conceivable to seal the gap with a seal member or the like. However, the belt may meander in the width direction during rotation of the belt, and a stable sealing function cannot be exhibited simply by providing a seal member.

  The present invention solves the problems of the conventional image forming apparatus, prevents leakage of foreign matter stored in the foreign matter container, and can exhibit a stable sealing function even if the belt meanders. An object is to provide an image forming apparatus.

  Therefore, in the belt device of the present invention, a plurality of rollers, a belt stretched around the plurality of rollers, a cleaning member that contacts the belt and removes foreign matters attached to the belt, and the belt A support roller that is opposed to the cleaning member and is longer than the length of the belt plus a meandering distance in the width direction of the belt, a storage portion that stores foreign matter removed by the cleaning member, and the belt And a sealing member that contacts the support roller and prevents leakage of foreign matter accommodated in the accommodating portion, and the length of the sealing member in the width direction of the belt is longer than the meandering distance. .

  According to the present invention, in the belt device, the cleaning member that contacts the belt, the support roller that is opposed to the cleaning member across the belt, and that is longer than the length of the belt plus the meandering distance in the width direction of the belt, And a sealing member that contains the foreign matter removed by the cleaning member, and a sealing member that contacts the belt and the support roller to prevent leakage of the foreign matter contained in the accommodating portion, and seals the belt in the width direction. The length of the stop member is longer than the meandering distance in the width direction of the belt. Thereby, it is possible to reliably prevent leakage of the foreign matter accommodated in the accommodating portion and to exhibit a stable sealing function even if the belt meanders.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 2 is a schematic diagram of the image forming apparatus according to the first embodiment of the present invention.

  In the figure, reference numeral 10 denotes a paper tray, which is detachably attached to the image forming apparatus, and paper 11 as a recording medium is stacked therein. Inside the paper tray 10, a paper stacking plate 12 is rotatably disposed on a support shaft (not shown), and the paper 11 is stacked on the paper stacking plate 12. The paper tray 10 is provided with a guide member (not shown) that regulates the stacking position of the paper 11, and the position of the side surface of the paper 11 in the direction orthogonal to the feeding direction of the paper 11 (right direction in the drawing) The stacking position of the paper 11 with respect to the feeding direction of the paper 11 is regulated to be constant.

  On the feeding side of the paper tray 10, a lift-up lever 13 is rotatably disposed on a support shaft (not shown), and the support shaft is engaged with a motor 14 so as to be able to contact and separate. When the paper tray 10 is inserted into the image forming apparatus, the lift-up lever 13 and the motor 14 are engaged, and a control unit (not shown) drives the motor 14. As the lift-up lever 13 rotates, the tip of the lift-up lever 13 lifts the bottom of the paper stacking plate 12 and the paper 11 stacked on the paper stacking plate 12 rises. And if the paper 11 raises to a certain height, the raise detection part 21 will detect and the said control part will stop the motor 14 based on the information which the said raise detection part 21 detected.

  Further, on the feeding side of the paper tray 10, a paper feeding unit 20 that feeds the paper 11 one by one from the top is disposed. The paper feeding unit 20 includes a pickup roller 22 disposed so as to be pressed against the paper 11 raised to a certain height, a feed roller 23 that separates the paper 11 fed by the pickup roller 22 one by one, and a retard A pair of rollers 24. The paper feeding unit 20 includes a paper presence / absence detection unit 25 that detects the presence / absence of the paper 11 and a paper remaining amount detection unit 26 that detects the remaining amount of the paper 11.

  Then, the paper 11 that has been fed out from the paper feeding unit 20 as a single sheet is sent to the paper transport unit 30. The fed paper 11 passes through the paper sensor 31 and is sent to the conveyance roller pair 32. The transport roller pair 32 is driven by a drive unit (not shown) controlled by the control unit based on the timing when the paper 11 passes the paper sensor 31 and feeds the paper 11. In general, by delaying the timing at which the conveying roller pair 32 starts to rotate from the timing at which the sheet sensor 31 has passed, the sheet 11 is pushed into the pressure contact portion of the conveying roller pair 32 and the skew of the sheet 11 is corrected. .

  Next, the paper 11 sent out from the transport roller pair 32 passes through the paper sensor 33 and is sent to the transport roller pair 34. The transport roller pair 34 is rotated by a driving unit (not shown) from the time when the paper 11 passes through the paper sensor 33 and feeds the paper 11 without stopping. The paper 11 sent out by the transport roller pair 34 passes through the writing sensor 35 and is sent to the image forming unit 40.

  The image forming unit 40 includes four toner image forming units 41 arranged in series, and a belt device that transfers the toner image formed by the toner image forming unit 41 to the upper surface of the paper 11 by Coulomb force. The transfer portion 50 is provided. The toner image forming unit 41 forms an electrostatic latent image on the surface of the charged OPC drum 42, an OPC (Organic Photo Conductor) drum 42 that carries a toner image, a charging roller 45 that charges the surface of the OPC drum 42. It has an LED head 43 comprising an LED (Light Emitting Diode) array, a developing roller 44 for forming a toner image on an electrostatic latent image by frictional charging, and a toner supply unit 46 for supplying toner.

  The transfer unit 50 is a transfer belt 51 serving as a belt for electrostatically attracting and transporting the paper 11 and a drive roller 52 serving as a roller that is rotated by a driving unit (not shown) and drives the stretched transfer belt 51. An idle roller 53 that is paired with the drive roller 52 and on which the transfer belt 51 is stretched is disposed so as to face the toner image forming portion 41 and to be in pressure contact with the OPC drum 42. A transfer roller 54 for applying a voltage so as to transfer the paper 11, a cleaning blade 55 as a cleaning member for scraping and cleaning the toner adhering to the transfer belt 51, and a cleaning blade sandwiching the transfer belt 51 And a support roller 57 as a support roller opposite to the roller 55 and the cleaning blade 55. Having a toner box 56 as container for foreign matter compost (Thailand) product such as toner scraped Te.

  The toner image forming unit 41 and the transfer belt 51 are driven in synchronization, and the toner images are sequentially superimposed and transferred onto the sheet 11 electrostatically attracted to the transfer belt 51. The sheet 11 on which the image has been transferred by the image forming unit 40 is sent to a fixing unit 90 that fuses the toner image to the sheet 11 with heat and pressure.

  The fixing unit 90 includes a halogen lamp 93 serving as a heat source therein, and includes a roller pair including an upper roller 91 and a lower roller 92 each having a surface formed of an elastic body, and is fed from the image forming unit 40. Heat and pressure are applied to the toner image on the paper 11 to melt the toner image and fix it on the paper 11. Thereafter, the paper 11 is discharged to the stacker unit 95 by the discharge roller 94.

  Next, the configuration of the transfer unit 50 will be described in detail.

  FIG. 3 is a side view showing the configuration of the belt device according to the first embodiment of the present invention.

  As shown in the figure, the transfer unit 50 is rotatably supported by a belt frame 61, and a surface of which a gear (not shown) is fixedly locked to an end portion is a high-friction drive roller 52, and both end portions are rotated to a bearing 62. An idle roller 53 and the like that are supported are provided. The bearing 62 is slidably supported in a hole 63 b of an arm 63 that is rotatably supported by the belt frame 61, and is urged by a spring 58 to stretch the transfer belt 51. That is, on the belt frame 61, an arm 63 as a roller shaft displacement member is rotatably supported by a rotating shaft 63a, and a bearing 62 is slidably disposed in a hole 63b of the arm 63, so that an idle roller 53 is mounted. Support for rotation. As a result, the transfer belt 51 travels in the direction indicated by the arrow a.

  Next, a mechanism for correcting the meandering of the transfer belt 51 will be described. The mechanism is substantially the same as the belt meandering correction mechanism described in JP-A-2006-162659. The cleaning unit of the transfer unit 50 will be described later.

  FIG. 4 is a top view showing the configuration of the belt device according to the first embodiment of the present invention, FIG. 5 is a trihedral view showing the configuration of the roller tilting lever according to the first embodiment of the present invention, and FIG. FIG. 5 is a diagram illustrating an operation of correcting the meandering of the belt device according to the first embodiment, and is a cross-sectional view taken along line BB in FIG. 3. 5A is a top view, FIG. 5B is a side view, and FIG. 5C is a front view.

  As shown in FIG. 4, a pulley 71 having a flange with which the end of the transfer belt 51 abuts on the outer periphery is formed coaxially with one end of the idle roller 53 and is slidable in the axial direction. It is arranged so as to function as an axial movement detection member. Between the arm 63 and the pulley 71, a roller tilting lever 64 as a roller shaft displacement member having a rotating shaft 64a inclined with respect to the rotating shaft O1 of the drive roller 52 is disposed. Note that O2 is a rotation shaft of the idle roller 53.

  As shown in FIG. 5, the rotating shaft 64a of the roller tilting lever 64 is inclined by an angle θ with respect to the rotating shaft O1 of the drive roller 52, and an idle roller 53 is provided in the elliptical hole portion 64b. The shaft 64 is rotatably and slidably penetrated, and a convex portion 64 c is disposed so as to contact the pulley 71.

  Since the roller tilting lever 64 has an inclined rotating shaft 64a, when the roller tilting lever 64 is rotated, the roller tilting lever 64 rotates in a locus 64d as shown in FIG. Therefore, when the shaft end portion of the idle roller 53 is inclined downward in FIG. 3, the roller tilting lever 64 also rotates downward and approaches the idle roller 53 and operates to push in the pulley 71. . Similarly, when the shaft end portion of the idle roller 53 is inclined upward, the roller tilting lever 64 rotates upward and away from the idle roller 53.

  As shown in FIG. 6A, when the transfer belt 51 is on the right side, the pulley 71 is positioned on the right side according to the transfer belt 51. Accordingly, the roller tilting lever 64 moves downward due to the weight of the idle roller 53, rotates around the rotation shaft 64a, and is biased toward the idle roller 53 side. Therefore, the idle roller 53 tilts as shown in FIG.

Here, when the drive roller 52 is rotated and the transfer belt 51 starts to travel, the belt meanders in the direction indicated by the arrow C, and accordingly, the pulley 71 is pushed by the transfer belt 51 and indicated by the arrow C. Move in the direction. Incidentally, l ₁ and l ₂ shown in FIG. 6 is a meandering distance described below.

  Since the roller tilting lever 64 is in contact with the pulley 71 at the convex portion 64c, the roller tilting lever 64 rotates concentrically with the rotating shaft 64a inclined by being pushed by the pulley 71, and is positioned as shown in FIG. 6B. become. In the state as shown in FIG. 6 (b), the rotation axis O2 of the idle roller 53 and the rotation axis O1 of the drive roller 52 are substantially parallel, so that the meandering of the transfer belt 51 is reduced and meanders at this position. Will settle and run stably.

  When the belt is shifted to the left side, the pulley 71 is also located on the left side. Accordingly, the roller tilting lever 64 is urged to the left side, so that it rotates about the rotation shaft 64a, and FIG. As shown, the idle roller 53 tilts.

  When the idle roller 53 tilts as shown in FIG. 6C, the transfer belt 51 meanders in the direction indicated by the arrow D as the belt travels, and the pulley 71 is similarly indicated by the arrow D. Move in the direction. The roller tilting lever 64 rotates downward so that the convex portion 64c comes into contact with the pulley 71 due to its own weight, and the roller tilting lever 64 rotates toward the idle roller 53, and in the state shown in FIG. 51 runs stably.

  Next, the cleaning unit of the transfer unit 50 will be described in detail.

  In the present embodiment, both ends of the support roller 57 are rotatably held by holders 60 as holding members, and the holders 60 are fixedly supported by the belt frame 61. The support roller 57 is made of metal, and the rotation shaft is integrally formed. The holder 60 is made of resin.

  Further, a cleaning blade 55 is attached to the holder 60. The cleaning blade 55 sandwiches the transfer belt 51 between the support roller 57 and its tip scrapes off foreign matters such as toner on the surface of the transfer belt 51. The cleaning blade 55 is an elongated plate-like member made of, for example, urethane rubber, and is bonded to a blade holder 55a made of a highly rigid material such as a sheet metal by, for example, a hot melt adhesive. The blade holder 55a is fixed to the holder 60 with, for example, screws.

  The belt frame 61 is provided with a toner box 56 having a box shape for storing foreign matter scraped off by the cleaning blade 55. In this case, the attachment post 56b of the belt frame 61 is inserted into the attachment hole 56a formed in the toner box 56, so that the toner box 56 is attached. In this case, a seal is provided between the cleaning blade 55 and the toner box 56 in order to securely store the foreign matter scraped off by the cleaning blade 55 and to prevent the stored foreign matter from leaking out. A mechanism is provided.

  In FIG. 3, reference numeral 68 denotes a seal film attached to the toner box 56, which is made of a flexible material such as a urethane film, and is in contact with the entire width of the transfer belt 51. Sealing is performed so that foreign matter contained in the box 56 does not leak. Reference numeral 66 denotes a box cover that closes the upper opening of the toner box 56 and seals it with the cleaning blade 55 over the entire width of the toner box 56.

  Next, the configuration of the sealing mechanism will be described in detail.

  FIG. 1 is a diagram showing a configuration of a seal mechanism according to the first embodiment of the present invention. 1A is a cross-sectional view taken along line AA in FIG. 3, and FIG. 1B is an enlarged view of a portion E in FIG.

As described above, the transfer belt 51 meanders within a certain range wider than the width LB of the transfer belt 51, that is, within a range obtained by adding the meandering distances l ₁ and l ₂ to LB.

The support roller 57 is formed longer than the length obtained by adding the meandering distances l ₁ and l ₂ to the width LB of the transfer belt 51. Note that LR is the length of the support roller 57. As shown in FIG. 6, the meandering distance l ₁ is the amount of displacement of the position of the transfer belt 51 when the transfer belt 51 is on the left side and when traveling stably, and the meandering distance l ₂ is This is the amount of deviation of the position of the transfer belt 51 when the transfer belt 51 is on the right side and when the transfer belt 51 travels stably.

  Further, at both ends of the toner box 56, seal members 69 as sealing members made of urethane foam are disposed at positions corresponding to both ends of the support roller 57. The seal member 69 is in contact with the surface of the transfer belt 51, and the width of the seal member 69 is such that the end of the transfer belt 51 is not exposed even when the transfer belt 51 meanders, and the end of the support roller 57 is exposed. It is formed so as to cover up to the outer range.

  Next, the operation of the image forming apparatus having the above configuration will be described. First, the operation of the entire image forming apparatus will be described.

  First, the operator mounts the paper tray 10 in which the paper 11 is stacked inside the image forming apparatus. At this time, the paper tray 10 is provided with a guide member (not shown) that regulates the stacking position of the paper 11, and the guide member is a side surface of the paper 11 in a direction orthogonal to the paper feeding direction (right direction in FIG. 2). Then, the stacking position of the sheets 11 with respect to the sheet feeding direction is regulated to be constant. When the paper tray 10 is mounted on the image forming apparatus, the lift-up lever 13 and the motor 14 are engaged, and the control unit drives the motor 14. As the lift-up lever 13 rotates, the tip of the lift-up lever 13 lifts the bottom of the paper stacking plate 12 and the paper 11 stacked on the paper stacking plate 12 rises. When the sheet 11 rises to a height at which it is pressed against the pickup roller 22, the rise detection unit 21 detects this, and the control unit stops the motor 14 based on the information detected by the rise detection unit 21.

  Then, image data is processed by an image processing unit (not shown), and a print command is sent to the control unit. A drive motor drives the pickup roller 22 to rotate. The paper 11 fed by the pickup roller 22 is conveyed to the nip position of the roller pair of the feed roller 23 and the retard roller 24 and separated one by one. Then, the paper 11 that has been fed out from the paper feeding unit 20 by one sheet is sent to the paper transport unit 30. The fed paper 11 passes through the paper sensor 31 and is sent to the conveyance roller pair 32. The transport roller pair 32 is driven by a driving unit controlled by the control unit based on the passage time of the paper sensor 31 and feeds the paper 11. In general, by delaying the timing at which the conveying roller pair 32 starts to rotate from the timing at which the sheet sensor 31 has passed, the sheet 11 is pushed into the pressure contact portion of the conveying roller pair 32 and the skew of the sheet 11 is corrected. .

  Then, the paper 11 sent out from the transport roller pair 32 passes through the paper sensor 31 and is sent to the transport roller pair 34. The transport roller pair 34 is rotated by the driving unit from the time when the paper 11 passes the paper sensor 31 and feeds the paper 11 without stopping. The paper 11 sent out by the transport roller pair 34 passes through the writing sensor 35 and is sent to the image forming unit 40.

  The image forming unit 40 generates an electrostatic latent image on the surface of the OPC drum 42 charged by the charging roller 45 when the LED head 43 irradiates the surface of the OPC drum 42 based on the image data sent from the image processing unit. Form. Then, the toner supplied from the toner supply unit 46 adheres to the OPC drum 42 by the developing roller 44, and a toner image is formed. The toner image carried on the surface of the OPC drum 42 is transferred onto the paper 11 that is electrostatically attracted to the transfer belt 51 and conveyed at a pressure contact portion with the transfer roller 54. The transfer belt 51 is driven by the drive unit rotating the drive roller 52 and conveys the paper 11. Here, the OPC drum 42 and the transfer belt 51 of the toner image forming section 41 are driven in synchronization, and the toner images are sequentially superimposed and transferred onto the sheet 11 electrostatically attracted to the transfer belt 51. The sheet 11 on which the toner image has been transferred by the image forming unit 40 is sent to a fixing unit 90 that fuses the toner image to the sheet 11 with heat and pressure.

  The toner image on the paper 11 sent out from the image forming unit 40 is melted and fixed on the paper 11 by applying heat and pressure. Thereafter, the sheet 11 is discharged to the stacker unit 95 by the discharge roller pair 94.

  Next, the operation of the transfer unit 50 will be described.

  FIG. 7 is a view showing a meandering state of the transfer belt according to the first embodiment of the present invention. 7A shows the case where the right end of the idle roller is twisted (twisted) upward, and FIG. 7B shows the case where the right end of the idle roller is twisted downward.

  First, when the drive roller 52 is rotated in the direction indicated by the arrow F by the drive unit, the transfer belt 51 is rotated in the direction indicated by the arrow a in FIG. In the figure, arrow a indicates the rotation direction of the transfer belt 51, arrows b and c indicate the meandering direction of the transfer belt 51, arrow F indicates the rotation direction of the drive roller 52, and arrow G indicates the locus of the transfer belt 51. The arrow H indicates the amount of movement of the transfer belt 51 per rotation. In the arrow G, the solid line indicates the locus on the front side of the transfer belt 51, and the broken line indicates the locus on the back side of the transfer belt 51.

  Here, during the rotation of the transfer belt 51, the parallelism between the drive roller 52 and the idle roller 53 is poor. For example, as shown in FIG. When twisted in the direction, the transfer belt 51 rotates perpendicularly to the axis of the wound idle roller 53, and thus shows a trajectory as indicated by an arrow G. As a result, the transfer belt 51 meanders in a direction perpendicular to the rotational direction indicated by the arrow a, that is, in the direction indicated by the arrow b. On the other hand, as shown in FIG. 7B, when the right end of the idle roller 53 is twisted downward, the transfer belt 51 meanders in the direction indicated by the arrow c.

  At this time, the amount of movement of the transfer belt 51 indicated by the arrow H, that is, the amount of meandering increases in proportion to the twisted amount of the drive roller 52 and the idle roller 53. Therefore, in this embodiment, the transfer belt As the idle roller 53 operates as shown in FIG. 6 according to the meandering position 51, the meandering of the transfer belt 51 is corrected.

When the transfer belt 51 rotates, the seal member 69 disposed in the toner box 56 comes into sliding contact with the transfer belt 51. When the transfer belt 51 meanders, the position at which the seal member 69 contacts the end of the transfer belt 51 changes according to the meander, but the width of the seal member 69 is between the meandering distances l ₁ and l _{2 on} the left and right. Since it is formed so as to be wider than the total value, the sealing performance of the toner box 56 is not impaired.

Further, as shown in FIG. 1, the length LR of the support roller 57 is a value obtained by adding the total value of the left and right meandering distances l ₁ and l ₂ to the width LB of the transfer belt 51, that is, (LB + (l ₁ +1 ₂ ), the support roller 57 is also opposed to the end of the transfer belt 51, and the seal member 69 can be firmly attached to the transfer belt 51 also at the end of the transfer belt 51. Therefore, it is possible to restrict the deformation of the end portion of the transfer belt 51 in the vertical direction and suppress the damage of the seal member 69 due to the displacement of the end portion, thereby maintaining a stable sealing performance for a long time.

As described above, in the present embodiment, the seal member 69 formed wider than the total value of the left and right meandering distances l ₁ and l ₂ of the transfer belt 51 and the left and right meanders in the width LB of the transfer belt 51. The end portion of the transfer belt 51 is supported in close contact with both sides by a support roller 57 formed longer than the sum of the distances l ₁ and l ₂ . Therefore, even if the transfer belt 51 meanders, the foreign matter accommodated from the toner box 56 can be reliably prevented from leaking. Further, since the deformation of the end portion of the transfer belt 51 in the vertical direction can be restricted, damage to the seal member 69 due to the deformation of the end portion can be suppressed and stable sealing performance can be exhibited for a long period of time.

  Next, a second embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st Embodiment, the description is abbreviate | omitted by providing the same code | symbol. The description of the same operations and effects as those of the first embodiment is also omitted.

  FIG. 8 is a diagram showing a configuration of a sealing mechanism in the second embodiment of the present invention, and FIG. 9 is a diagram showing a support roller support portion of the holder in the second embodiment of the present invention.

In this embodiment, the length LR of the support roller 57 is shorter than that of the first embodiment and shorter than the width LB of the transfer belt 51, as shown in FIG. Further, as shown in FIG. 9, an arc portion 60 a of a holder 60 that rotatably supports the support roller 57 is formed with the same radius R as the support roller 57, and left and right of the transfer belt 51. It is formed larger than the total value of the meandering distances l ₁ and l ₂ .

  Since the configuration of other points is the same as that of the first embodiment, description thereof is omitted.

  Next, the operation of the transfer unit 50 in the present embodiment will be described.

  First, when the transfer belt 51 rotates, the seal member 69 disposed in the toner box 56 comes into sliding contact with the transfer belt 51. In the present embodiment, unlike the first embodiment, the support roller 57 does not face the end portion of the transfer belt 51. However, the arc portion 60 a of the holder 60 that is coaxial with the support roller 57 and has the same radius R corresponds to the end portion of the transfer belt 51. Therefore, the seal member 69 can be firmly attached to the transfer belt 51 even at the end portion of the transfer belt 51, and foreign matter does not leak from the toner box 56.

  Further, since the deformation of the end portion of the transfer belt 51 in the vertical direction can be restricted, damage to the seal member 69 due to the deformation of the end portion can be suppressed, and a stable sealing performance can be maintained for a long time.

  Further, since the mass of the support roller 57 is shortened, the contact pressure between the rotation shaft of the support roller 57 and the holder 60 can be reduced, and the durability of the transfer unit 50 can be improved. it can. Further, since the support roller 57 is made of metal while the holder 60 is made of resin, the decrease in mass due to the support roller 57 becoming shorter than the increase in mass due to the increase in the width of the holder 60. The degree is larger. Therefore, the transfer unit 50 as a whole can be reduced in weight, and usability when the transfer unit 50 is attached and detached can be improved.

Thus, in the present embodiment, the length LR of the support roller 57 is shorter than the width LB of the transfer belt 51, and the arc portion 60a of the holder 60 is formed coaxially with the support roller 57 with the same radius R. Further, the transfer belt 51 is formed to be larger than the total value of the left and right meandering distances l ₁ and l ₂ . Therefore, since the weight of the metal support roller 57 is reduced, the contact pressure between the rotating shaft of the support roller 57 and the holder 60 can be reduced, and the durability of the transfer unit 50 can be improved. Furthermore, usability when attaching and detaching the transfer unit 50 can be improved.

  Next, a third embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st and 2nd embodiment, the description is abbreviate | omitted by providing the same code | symbol. The description of the same operations and effects as those of the first and second embodiments is also omitted.

  FIG. 10 is a diagram showing a configuration of a seal mechanism according to the third embodiment of the present invention.

In the present embodiment, a roller 67 as a rotating member formed with the same radius as the support roller 57 is rotatably attached to the rotation shaft of the support roller 57. The width of the roller 67 is formed to be larger than the total value of the left and right meandering distances l ₁ and l ₂ of the transfer belt 51.

  Since the configuration of other points is the same as that of the first and second embodiments, the description thereof is omitted.

  Next, the operation of the transfer unit 50 in the present embodiment will be described.

  The operation of the transfer unit 50 in the present embodiment is the same as that of the second embodiment, but in the second embodiment, the end of the transfer belt 51 is in sliding contact with the arc portion 60 a of the holder 60. On the other hand, in the present embodiment, the end portion of the transfer belt 51 comes into contact with the rotatable roller 67. Accordingly, since the roller 67 freely rotates as the transfer belt 51 moves, there is no sliding contact load on the end of the transfer belt 51, and the end of the transfer belt 51 is scratched or cracked. There is nothing. Further, it is possible to provide a transfer unit 50 that is lighter and more durable than the first embodiment.

  As described above, in the present embodiment, the entire transfer unit 50 can be further reduced in weight by shortening the length LR of the support roller 57 as compared with the first embodiment. Also, the durability of the transfer belt 51 can be improved by disposing a rotatable roller 67 as compared with the second embodiment.

  Next, a fourth embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st-3rd embodiment, the description is abbreviate | omitted by providing the same code | symbol. The description of the same operations and effects as those of the first to third embodiments is also omitted.

  FIG. 11 is a diagram showing a configuration of a sealing mechanism in the fourth embodiment of the present invention, FIG. 12 is a diagram for explaining the bending (deflection) of the cleaning blade in the fourth embodiment of the present invention, and FIG. These are sectional drawings which show the modification of the support roller in the 4th Embodiment of this invention. In FIG. 12, (a) is a perspective view, (b) is a cross-sectional view taken along line II of (a), and (c) is a cross-sectional view taken along line JJ of (a).

In the present embodiment, as shown in FIG. 11, a taper roller 77 as a rotating member having a conical shape is rotatably attached to the rotating shaft of the support roller 57. The width of the taper roller 77 is larger than the total value of the meandering distances l ₁ and l _{2 on} the left and right of the transfer belt 51. Further, the radius of the small diameter portion of the taper roller 77 is the same as the radius of the support roller 57, and the radius of the large diameter portion of the taper roller 77 is larger than the radius of the support roller 57. And the taper roller 77 is attached so that a small diameter part may be located inside.

  Further, as shown in FIG. 12, the cleaning blade 55 is disposed such that the free end that is in pressure contact with the transfer belt 51 is upstream of the fixed end in the traveling direction of the transfer belt 51. That is, a counter is arranged. In FIG. 12, an arrow K indicates the traveling direction of the transfer belt 51. The end of the cleaning blade 55 is disposed so as to contact the taper roller 77 through the transfer belt 51.

  Next, the operation of the transfer unit 50 in the present embodiment will be described.

  In the present embodiment, since the outer diameter of the tapered roller 77 increases toward the outer side, the end of the cleaning blade 55 has a large diameter of the tapered roller 77 as shown in FIG. Press contact with the part. Therefore, as shown in FIGS. 12B and 12C, the deflection of the cleaning blade 55 is larger at the end than at the center.

  In the cleaning blade 55 provided with a counter, there is a possibility that the free end is buckled and deformed due to friction with the transfer belt 51 and the transfer belt 51 moves downstream in the traveling direction. Further, since the end portion of the cleaning blade 55 has a buckling strength lower than that of the central portion, the wrinkle easily occurs at the end portion. However, in this embodiment, since the end of the cleaning blade 55 is pressed against the large diameter portion of the taper roller 77, the end portion is bent more than the central portion, the buckling strength of the end portion is increased, and the occurrence of wrinkling is generated. Can be prevented.

  Instead of attaching the taper roller 77 to the rotation shaft of the support roller 57, the support roller 57 itself can be processed so as to have a cross-sectional shape as shown in FIG.

  As described above, in the present embodiment, the end of the cleaning blade 55 is pressed against the tapered roller 77 by disposing the tapered roller 77, so that the end of the cleaning blade 55 is bent more than the central portion. It becomes large, the buckling strength of the end portion increases, and the occurrence of wrinkles can be prevented. Therefore, the reliability of the transfer unit 50 can be improved.

  In the first to fourth embodiments, an example in which the present invention is applied to a paper conveying belt of an electrophotographic printer has been described. However, the present invention is not limited to an intermediate transfer belt and a photosensitive belt of an electrophotographic printer. Etc. are available.

  The present invention is not limited to the above-described embodiment, and various modifications can be made based on the spirit of the present invention, and they are not excluded from the scope of the present invention.

It is a figure which shows the structure of the seal mechanism in the 1st Embodiment of this invention. 1 is a schematic diagram of an image forming apparatus according to a first embodiment of the present invention. It is a side view which shows the structure of the belt apparatus in the 1st Embodiment of this invention. It is a top view which shows the structure of the belt apparatus in the 1st Embodiment of this invention. It is a three-plane figure which shows the structure of the roller tilting lever in the 1st Embodiment of this invention. It is a figure which shows the operation | movement which correct | amends the meandering of the belt apparatus in the 1st Embodiment of this invention, and is BB sectional drawing of FIG. It is a figure which shows the meandering state of the transfer belt in the 1st Embodiment of this invention. It is a figure which shows the structure of the seal mechanism in the 2nd Embodiment of this invention. It is a figure which shows the support part of the support roller of the holder in the 2nd Embodiment of this invention. It is a figure which shows the structure of the seal mechanism in the 3rd Embodiment of this invention. It is a figure which shows the structure of the seal mechanism in the 4th Embodiment of this invention. It is a figure explaining the bending of the cleaning blade in the 4th Embodiment of this invention. It is sectional drawing which shows the modification of the support roller in the 4th Embodiment of this invention.

Explanation of symbols

50 Transfer section 51 Transfer belt 52 Drive roller 53 Idle roller 55 Cleaning blade 56 Toner box 57 Support roller 59 Seal member 60 Holder 67 Roller 77 Tapered roller

Claims (8)

(A) a plurality of rollers;
(B) a belt stretched around the plurality of rollers;
(C) a cleaning member that contacts the belt and removes foreign matter adhering to the belt;
(D) a support roller that is opposed to the cleaning member with the belt interposed therebetween and is longer than a length obtained by adding a meandering distance in the width direction of the belt to the width of the belt;
(E) an accommodating portion for accommodating the foreign matter removed by the cleaning member;
(F) a sealing member that is in contact with the belt and the support roller and prevents leakage of foreign matter stored in the storage unit;
(G) The length of the said sealing member regarding the width direction of the said belt is longer than the said meandering distance, The belt apparatus characterized by the above-mentioned. The belt device according to claim 1, wherein both end portions of the support roller gradually increase in diameter toward the outer side in the rotation axis direction. (A) a plurality of rollers;
(B) a belt stretched around the plurality of rollers;
(C) a cleaning member that contacts the belt and removes foreign matter adhering to the belt;
(D) a support roller facing the cleaning member via the belt and shorter than the width of the belt;
(E) a holding member that contacts the belt and rotatably holds the support roller at both ends of the support roller;
(F) an accommodating portion for accommodating the foreign matter removed by the cleaning member;
(G) a sealing member that contacts the belt and the holding member, and prevents leakage of foreign matter accommodated in the accommodating portion;
(H) The belt device characterized in that the length of the holding member and the length of the sealing member in the width direction of the belt are longer than the meandering distance in the width direction of the belt. The belt device according to claim 3, wherein a surface of the holding member that contacts the belt is an arc surface having a diameter substantially the same as the diameter of the support roller. (A) a plurality of rollers;
(B) a belt stretched around the plurality of rollers;
(C) a cleaning member that contacts the belt and removes foreign matter adhering to the belt;
(D) a support roller facing the cleaning member via the belt and shorter than the width of the belt;
(E) a holding member that rotatably holds the support roller at both ends of the support roller;
(F) a rotating member that contacts the belt and is rotatable with respect to a rotating shaft of the supporting roller between the supporting roller and the holding member;
(G) an accommodating portion for accommodating the foreign matter removed by the cleaning member;
(H) a sealing member that contacts the belt and the rotating member, and prevents leakage of foreign matter accommodated in the accommodating portion;
(I) The belt device characterized in that the length of the rotating member and the length of the sealing member in the width direction of the belt are longer than the meandering distance in the width direction of the belt. The belt device according to claim 5, wherein the rotating member has a diameter substantially the same as a diameter of the support roller. The belt device according to claim 5, wherein the rotating member gradually increases in diameter toward an outer side in a rotation axis direction of the support roller. An image forming apparatus comprising the belt device according to claim 1.

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