JP2018004773A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation device that, when a cleaning unit oscillates accompanied by oscillation of a steering unit, attains reduction in operation failure of the steering unit and reduction in toner leakage from a toner emission port.SOLUTION: Regarding a steering unit 1 integrated with a cleaning unit 31 and oscillatable, a toner emission port 40 is provided at a position including a vertical surface passing through an oscillation center of a steering roller 2. In this case, even when the steering unit 1 oscillates, a position change in a gravity direction relative to a recovery container of the toner emission port 40 can be made small, and thus, an encapsulation member 38 can be formed into a size smaller than a conventional member. Even if the encapsulation member 38 is formed into the smaller size than conventionally, upon oscillation of the steering unit 1, recovery toner is not leaked due to a gap occurring between the recovery container and the encapsulation member, and further, at a time of steering operation, a load to be applied to the steering unit 1 is small, which in turn hardly causes operation failures in the steering operation.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image forming apparatus using electrophotographic technology such as a printer, a copying machine, a facsimile machine, or a multifunction machine.

  As an image forming apparatus using an electrophotographic technique, a so-called intermediate transfer type that forms a full-color toner image on an intermediate transfer belt (ITB) that is an endless belt is known. The intermediate transfer belt is rotatably stretched by a plurality of stretching rollers. In that case, depending on the outer diameter accuracy of each roller, the relative alignment accuracy between the rollers, and the like, a so-called “belt shift” in which a rotating intermediate transfer belt (hereinafter simply referred to as a belt) approaches one end of the roller. Can occur.

  In view of this, an image forming apparatus having a steering unit that performs a steering operation based on control of an actuator or the like in order to correct the “belt deviation” and position the belt at a predetermined position in the width direction has been proposed (patent). Reference 1). In this apparatus, an actuator or the like is appropriately controlled according to the amount of meandering of the belt, the amount of meandering displacement, the meandering speed, and the like, and the steering unit is swung based on this. “Belt shift” is corrected as the steering unit swings.

  An image forming apparatus having a simple configuration steering unit that can perform a steering operation without controlling an actuator or the like has been proposed (Patent Document 2). In this apparatus, the steering unit automatically swings according to the balance of frictional force generated between one of the stretching rollers called a steering roller and the belt.

  The image forming apparatus includes a cleaning unit that removes, from the belt, collected toner that needs to be collected remaining on the belt after transfer, and a collection container that receives the collected collected toner from the cleaning unit and stores the collected toner. As in the apparatus described in Patent Document 2 described above, recently, a cleaning unit is provided integrally with the steering unit in order to reduce the size of the apparatus. In that case, the cleaning unit swings together with the swing of the steering unit. Therefore, the cleaning unit is provided with a toner discharge port for transferring the collected toner to and from the collection container. A sealing member that can be elastically deformed is disposed at the toner discharge port in order to prevent a clearance from being generated between the recovery unit and the recovery container when the steering unit is swung. . The sealing member is formed in a size that does not create a gap when the cleaning unit is farthest from the collection container, and is therefore deformed so as to be crushed when the cleaning unit approaches the collection container.

JP-A-9-169449 Japanese Patent Laying-Open No. 2015-64503

  Conventionally, when the swing of the cleaning unit increases, the load applied to the steering unit increases, and the steering operation may not be performed properly. That is, the force applied when crushing the sealing member acts as a load on the steering unit. Conventionally, the fluctuation of the toner discharge port with respect to the collection container due to the swinging is large and the load is large. It was easy for malfunction to occur. However, just because the sealing member is formed small in order to reduce the force applied when crushing the sealing member, that is, the load applied to the steering unit at the time of swinging, when the steering unit swings, A gap is likely to occur between them. That is, the collected toner is likely to leak.

  The present invention has been made in view of the above problems, and in the case where the cleaning unit swings with the swing of the steering unit, both reduction in malfunction of the steering unit and reduction in toner leakage from the toner discharge port are achieved. An object is to provide an image forming apparatus.

  An image forming apparatus according to the present invention includes an endless belt that rotates while supporting toner, a first roller that rotates by stretching the belt, and a belt that rotates with the first roller. A second roller; a steering mechanism that swings the second roller relative to the first roller to move the belt in the direction of the rotation axis of the second roller; and a cleaning member that removes toner on the belt; A storage container for storing the toner removed from the belt, and a discharge port provided in the storage container for discharging the toner in the storage container, and swinging integrally with the second roller. A cleaning unit that is disposed below the discharge port in the direction of gravity, has a receiving container that is connected to the discharge port and receives toner discharged from the discharge port, and the discharge port. An elastic sealing member provided so as to close a gap with the receiving port, and the discharge port is a vertical plane passing through the swing center of the second roller in the rotation axis direction of the second roller. It is arrange | positioned in the position containing.

  According to the present invention, when the cleaning unit swings with respect to the collection container as the second roller swings, the toner leakage from the discharge port due to the swing of the cleaning unit is reduced, and the steering is It is easy to make it difficult to cause operation failure.

1 is a schematic diagram illustrating a configuration of an image forming apparatus according to an embodiment. The perspective view which shows the belt unit of 1st embodiment. The perspective view which shows the steering unit of 1st embodiment. Schematic which shows the one end part of a steering unit. Schematic which shows an automatic alignment mechanism part. It is a figure which shows the relationship of the contact width of an intermediate transfer belt and a sliding ring member, (a) is a case where a belt width is wider than a roller width, (b) is a case where a belt width is narrower than a roller width. The perspective view which shows the cleaning unit of 1st embodiment. Sectional drawing which shows a part of belt unit of 1st embodiment. FIG. 5 is a diagram illustrating a toner discharge port. The perspective view which shows the belt unit of 2nd embodiment. The side view which shows a part of belt unit of 2nd embodiment. The perspective view which shows the external appearance of the cleaning unit of 2nd embodiment.

<First embodiment>
The first embodiment will be described with reference to FIGS. 1 to 9. First, the configuration of the image forming apparatus of this embodiment will be described with reference to FIG. An image forming apparatus 90 shown in FIG. 1 is an image forming apparatus using electrophotographic technology, and four color image forming sections 109Y to 109K are arranged in the apparatus main body 90a in the rotation direction of the intermediate transfer belt 101 (the direction of arrow V in FIG. 1). ), And an intermediate transfer tandem system. In this embodiment, an intermediate transfer belt unit 100 (see FIG. 2) to be described later is detachably supported on the apparatus main body 90a by a support frame (not shown).

[Image forming apparatus]
A conveyance process of the recording material P in the image forming apparatus 90 will be described. The recording material P (sheet material such as paper, OHP sheet, etc.) is stored in a form that is stacked in the paper cassette 85, and is sent out to the transport path 79 by the paper feed roller 84 in accordance with the image formation timing. The recording material P delivered from the paper cassette 85 by the paper feed roller 84 is conveyed to a registration roller pair 83 disposed in the middle of the conveyance path 79. Then, skew correction and timing correction are performed by the registration roller pair 83, and the recording material P is sent to the secondary transfer portion T2. The secondary transfer portion T2 is a transfer nip portion formed by the opposing secondary transfer inner roller 110 and secondary transfer outer roller 111, and applies a predetermined pressure and secondary transfer voltage to the recording material P with toner. Adsorb the image.

  A process of forming an image sent to the secondary transfer portion T2 at the same timing as the above-described conveyance process of the recording material P to the secondary transfer portion T2 will be described. First, the image forming units 109Y to 109K will be described. The image forming units 109Y to 109K for the respective colors are configured substantially the same except that the color of the toner used in the developing device is different from yellow, magenta, cyan, and black. Therefore, the yellow (Y) image forming unit 109Y will be described below as a representative.

  In the image forming unit 109Y, a charging device 104, a developing device 106, a primary transfer roller 107, and a drum cleaning device 108 are arranged so as to surround the photosensitive drum 103. The photosensitive drum 103 has a photosensitive layer formed on the outer peripheral surface of an aluminum cylinder, and is rotated at a predetermined process speed. The surface of the rotating photosensitive drum 103 is uniformly charged in advance by a charging device 104, and then an electrostatic latent image is formed by an exposure device 105 driven based on a signal of image information. The exposure apparatus 105 scans the scanning line image data obtained by developing the separation color image of each color with a rotating mirror, and writes an electrostatic latent image of the image on the surface of the charged photosensitive drum 103.

  The electrostatic latent image formed on the surface of the photosensitive drum 103 is visualized through toner development by the developing device 106. Thereafter, a predetermined pressing force and a primary transfer voltage are applied by a primary transfer roller 107 disposed so as to face the photosensitive drum 103 and the intermediate transfer belt 101, and a toner image formed on the photosensitive drum 103 is applied to the intermediate transfer belt 101. Primary transcription. The intermediate transfer belt 101 is rotationally driven in the direction of arrow V in the figure.

  The process of forming each color image processed in parallel by the yellow, magenta, cyan, and black image forming units 109 </ b> Y to 109 </ b> K is performed at the timing when the toner image is sequentially superimposed on the upstream color toner image carried on the intermediate transfer belt 101. Is called. As a result, a full color toner image is finally formed on the intermediate transfer belt 101 and conveyed to the secondary transfer portion T2.

  As described above, with the conveyance process and the image formation process described above, the timing of the recording material P and the full-color toner image coincide with each other in the secondary transfer portion T2, and the secondary transfer is performed. The recording material P after the secondary transfer is conveyed to the fixing device 112, and the toner image is melted and fixed to the recording material P by a predetermined pressure and heat amount. The recording material P on which the image is fixed in this manner is discharged to the paper discharge tray 76 as the paper discharge roller 78 rotates.

  The toner remaining on the photosensitive drum 103 after the primary transfer is removed by the drum cleaning device 108. On the other hand, the toner (recovered toner) remaining on the intermediate transfer belt 101 after passing through the secondary transfer portion T2, that is, after the secondary transfer, is removed by the cleaning unit 31. As will be described later, the cleaning unit 31 is integrated with the intermediate transfer belt unit 100 (see FIG. 2). A collection container 70 for collecting collected toner is detachably attached to the apparatus main body 90a below the cleaning unit 31 in the gravity direction.

[Intermediate transfer belt unit]
FIG. 2 shows an intermediate transfer belt unit 100 (hereinafter simply referred to as a belt unit) of the first embodiment. The belt unit 100 of this embodiment is an automatic alignment type in which the steering unit 1 automatically swings according to the balance of frictional force generated between the sliding ring member 3 (see FIG. 3) and the intermediate transfer belt 101. .

  As shown in FIG. 2, the intermediate transfer belt 101 as a belt is integrated with the belt unit 100 together with the steering unit 1, the secondary transfer inner roller 110 as the first roller, and the stretching rollers 113 and 114. Further, a steering unit 1 and a cleaning unit 31 described later are integrated with the belt unit 100. In the present embodiment, the intermediate transfer belt 101 is rotated in response to the secondary transfer inner roller 110 being driven by a motor or the like (not shown) provided in the apparatus main body 90a. That is, the secondary transfer inner roller 110 functions as a driving roller for rotating the intermediate transfer belt 101.

The intermediate transfer belt 101 is stretched by a steering roller 2 as a second roller, a secondary transfer inner roller 110, and stretching rollers 113 and 114, and is rotated in the direction of arrow V in FIG. It is a belt. The material of the intermediate transfer belt 101 is preferably a highly rigid resin such as PVDF (polyvinylidene fluoride), polyamide, polyimide, PET (polyethylene terephthalate), and polycarbonate in order to reduce the generation of wrinkles. On the other hand, if the intermediate transfer belt 101 is too thin, it is difficult to obtain sufficient durability due to wear. On the other hand, if the intermediate transfer belt 101 is too thick, the rollers for stretching the belt are not appropriately bent and are likely to be dented or broken. . In view of this point, the intermediate transfer belt 101 desirably has a thickness of, for example, 0.02 mm to 0.50 mm. As an example of the intermediate transfer belt 101, for example, a resin belt having a film thickness of 0.08 mm using a polyimide having a tensile elastic modulus E = 18000 N / cm ² as a base layer is used.

  By the way, when the intermediate transfer belt 101 stretched by a plurality of rollers is rotated, meandering is likely to occur while the intermediate transfer belt 101 rotates and moves in the width direction perpendicular to the circumferential direction of the belt. The meandering of the intermediate transfer belt 101 may occur due to a shape error or displacement of each roller or belt that supports the intermediate transfer belt 101. When the intermediate transfer belt 101 meanders, the toner images of the respective colors are relatively displaced when the toner images of the respective colors are transferred and superimposed on the intermediate transfer belt 101, and this may cause image defects such as color misregistration and color unevenness. . Further, the intermediate transfer belt 101 exceeds the range that can be stretched by a roller, which may cause the intermediate transfer belt 101 to come into contact with other parts and break. Therefore, in the intermediate transfer type image forming apparatus 90 using the intermediate transfer belt 101, it is necessary to suppress meandering of the intermediate transfer belt 101.

  As a technique for converging the meandering of the intermediate transfer belt 101, a steering method is known. In the steering system, one (or two) of the plurality of stretching rollers that stretch the intermediate transfer belt 101 is tilted as the steering roller 2, and the intermediate transfer belt 101 is moved in the width direction to thereby perform intermediate transfer. The meandering of the belt 101 is suppressed. In the present embodiment, the steering unit 1 for that purpose is provided in the belt unit 100. The steering unit 1 swings so as to change the steering angle (also referred to as alignment) of the steering roller 2 with respect to the secondary transfer inner roller 110, and intersects the width direction of the intermediate transfer belt 101 (the rotational axis direction of the steering roller 2). Adjust the position in the width direction. That is, the steering unit 1 functions as a steering mechanism that corrects “belt deviation”.

[Steering unit]
The steering unit 1 of the first embodiment will be described. As shown in FIG. 3, the steering unit 1 includes the steering roller 2 described above and a swing plate 7 as a support member. The swing plate 7 rotatably supports the steering roller 2. Side support members 6 are formed at both ends of the swing plate 7 in the longitudinal direction (rotation axis direction of the steering roller 2), and the side support members 6 have slide groove portions 6a.

As shown in FIG. 4, a slide bearing member 4 that supports the roller shaft 30 so as not to rotate is slidably fitted in the slide groove 6a. The steering roller 2 is rotatably supported on the roller shaft 30. The slide bearing member 4 is urged by a tension spring (compression spring) 5 in the direction of arrow _PT (see FIG. 3) so as to be slidable along the slide groove 6a. Thus, the steering roller 2 has a function as a tension roller that applies a force to push the intermediate transfer belt 101 from the back surface to the front surface, and also has a function as a driven roller that rotates following the intermediate transfer belt 101. .

  On both ends in the width direction of the steering roller 2, sliding ring members 3 as fixed members are arranged. The sliding ring member 3 is fixed to the roller shaft 30 so as not to rotate using parallel pins or the like. The sliding ring member 3 has a higher frictional resistance than the steering roller 2 with respect to the intermediate transfer belt 101. Therefore, the steering roller 2 follows (rotates) the rotating intermediate transfer belt 101, but the sliding ring member 3 does not follow the rotating intermediate transfer belt 101 and can rub the rotating intermediate transfer belt 101. Such a sliding ring member 3 has a straight shape having a uniform outer diameter, and a tapered shape whose outer diameter continuously increases from the center side to the end side in the rotation axis direction of the steering roller 2. Used.

  The sliding ring member 3 may be provided so as to be rotatable like the steering roller 2. However, in this case, since the steering operation is performed, the torque required to rotate the sliding ring member 3 by the intermediate transfer belt 101 is larger than the torque required to rotate the steering roller 2 by the intermediate transfer belt 101. To.

  As shown in FIG. 3, the steering unit 1 is provided so as to be swingable in the direction of arrow S in the drawing with respect to the frame stay 8 by the automatic alignment mechanism 80 with the steering axis J as the swing center. The swing plate 7 is attached to the frame stay 8 so as to face along the longitudinal direction of the frame stay 8 (rotation axis direction of the steering roller 2). The frame stay 8 is a member that constitutes a part of the belt unit 100 (see FIG. 2), and is spanned between side plates on both sides of the belt unit 100. The swing plate 7 is swingably attached to the frame stay 8 about the steering axis J by an automatic centering mechanism 80 disposed at the center of the rotation direction (D) of the steering roller 2. . Two slide rollers 9 are rotatably provided at both ends of the frame stay 8 in the longitudinal direction, respectively, in order to reduce the rocking resistance of the rocking plate 7 with respect to the frame stay 8.

[Automatic alignment mechanism]
The automatic alignment mechanism 80 will be described with reference to FIG. As shown in FIG. 5, the automatic alignment mechanism portion 80 includes a steering shaft 21 having a key shape portion 21 </ b> D having two ends. The steering shaft 21 as a rotating shaft is fastened by screws 24 in a state where the steering shaft 21 is supported by the bearing 23 of the frame stay 8 and the key-shaped portion 21D is fitted to the swing plate 7.

  A thrust retaining member 26 is fixed to the other end of the steering shaft 21 opposite to the key-shaped portion 21D via the first support member 20 so that the steering shaft 21 does not come off from the bearing 23. . A second support member 25 is provided on the opposite side of the thrust retaining member 26 across the first support member 20 with respect to the rotational axis direction of the steering shaft 21. The second support member 25 is fixed to the frame stay 8 with screws 25a in a state where the steering shaft 21 is penetrated. In this way, the steering unit 1 is supported on the frame stay 8 by the steering shaft 21. In the case of the present embodiment, the automatic alignment mechanism 80 is disposed at the center of the steering unit 1 in the longitudinal direction (rotation axis direction of the steering roller 2) (see FIG. 3). It will be provided at the center in the rotational axis direction.

  In this embodiment, when the frictional resistance that increases or decreases according to the sliding range between any one of the sliding ring members 3 and the intermediate transfer belt 101 becomes a predetermined value or more, the swinging of the steering unit 1, that is, the steering operation is started. The That is, the “belt shift” may occur due to distortion of the apparatus main body 90a or load fluctuations on the intermediate transfer belt 101 during image formation. When “belt shift” occurs, the steering unit 1 swings so that the frictional resistance between the sliding ring member 3 and the intermediate transfer belt 101 is large and the frictional resistance is smaller than a predetermined value. “Belt shift” is corrected.

  Here, the width of the intermediate transfer belt 101 (belt width) is wider than the width of the steering roller 2 (roller width) and narrower than the width of the steering unit 1 (roller width + width of the sliding ring members 3 at both ends). Is preferred. When the belt width is wider than the roller width in FIG. 6A, and when the belt width is narrower than the roller width in FIG. 6B, the intermediate transfer belt 101 is in an ideal steady alignment state. The relationship of the engagement width between the transfer belt 101 and the sliding ring member 3 is shown. Note that an arrow V in the figure indicates the rotation direction of the intermediate transfer belt 101.

  As shown in FIG. 6A, when the belt width is wider than the roller width, the intermediate transfer belt 101 in an ideal steady alignment state is slid with an equal engagement width W with respect to the sliding ring member 3. Yes. In this case, even if a belt shift occurs, the intermediate transfer belt 101 is rubbed against one of the sliding ring members 3. That is, when the belt width is wider than the roller width, the intermediate transfer belt 101 always rubs against one or both of the sliding ring members 3. Therefore, as soon as the belt is deviated, a difference occurs in the frictional resistance with the sliding ring member 3 at both ends in the width direction of the intermediate transfer belt 101, and the steering operation is performed based on this difference. In this case, the temporal change in the steering angle of the steering unit 1 is unlikely to be rapid, that is, it is difficult to perform a rapid steering operation in which the intermediate transfer belt 101 moves quickly in the width direction.

  On the other hand, when the belt width is narrower than the roller width as shown in FIG. 6B, the intermediate transfer belt 101 in an ideal steady state is not slid by any sliding ring member 3. . In this case, even if the belt is deviated, until the intermediate transfer belt 101 is rubbed against any one of the sliding ring members 3, the intermediate transfer belt 101 is in contact with the sliding ring members 3 at both ends in the width direction. There is no difference in frictional resistance. Therefore, a time lag may occur before the steering operation is performed. In this case, since a large frictional resistance difference is abruptly generated as compared with the case where the belt width is wider than the roller width, the temporal change in the steering angle of the steering unit 1 tends to be abrupt. That is, an abrupt steering operation in which the intermediate transfer belt 101 moves in the width direction is easy to be performed. In view of this point, the belt width is preferably wider than the roller width.

[Cleaning unit]
Further, as shown in FIG. 2, a cleaning unit 31 is integrated with the belt unit 100. The cleaning unit 31 is provided on the opposite side of the steering unit 1 (specifically, the steering roller 2) with the intermediate transfer belt 101 interposed therebetween so as to be able to swing integrally with the steering unit 1. The cleaning unit 31 is supported on the steering unit 1 by, for example, plates (not shown) extending from both ends in the longitudinal direction of the swing plate 7 (see FIG. 3) toward the cleaning unit 31 side.

  The cleaning unit 31 will be described with reference to FIGS. As shown in FIG. 7, the cleaning unit 31 can be roughly divided into a cleaning blade 102 as a cleaning member and a cleaning container 28 as a storage container.

  The cleaning blade 102 is formed in a plate shape with, for example, urethane rubber and is in contact with the intermediate transfer belt 101 in the width direction. As shown in FIG. 8, the tip of the cleaning blade 102 is in contact with the surface of the intermediate transfer belt 101 in the counter direction. The contact state between the cleaning blade 102 and the intermediate transfer belt 101 is maintained regardless of the swinging of the cleaning unit 31. That is, even when the steering angle is generated in the steering unit 1, the cleaning blade 102 is kept in contact with the intermediate transfer belt 101 and can remove the collected toner on the intermediate transfer belt 101 (on the belt). The width of the cleaning blade 102 is preferably wider than the width of the intermediate transfer belt 101 and narrower than the width of the steering roller 2.

  The cleaning container 28 stores the collected toner removed from the intermediate transfer belt 101 by the cleaning blade 102. A conveying screw 36 that conveys the collected collected toner is rotatably provided in the cleaning container 28. A conveying screw 36 as a conveying member is arranged along the longitudinal direction of the cleaning container 28, and conveys the collected toner in the container from both ends in the longitudinal direction of the cleaning container 28 toward the center. As will be described later in this embodiment (see FIG. 9), the toner discharge port 40 is provided at the center in the longitudinal direction of the cleaning container 28 (the center in the rotational axis direction of the steering roller 2). It is transported toward the center of the direction. The collected toner in the cleaning container 28 is discharged from the toner discharge port 40 to the collection container 70.

  As shown in FIG. 7, the cleaning container 28 has an engaging portion 28a that protrudes toward the opposite side of the steering unit 1 as shown in FIG. The engaging portion 28a is engaged with an apparatus side such as the apparatus main body 90a so as to be swingable with respect to the apparatus main body 90a with the steering axis J as a swing center. That is, the cleaning unit 31 is supported not only by the steering unit 1 but also by the apparatus main body 90a. The reason why the cleaning unit 31 is also supported by the apparatus main body 90a is to reduce an increase in the swing load of the steering unit 1. That is, as already described, the steering unit 1 is supported by the frame stay 8 (see FIG. 3) by the steering shaft 21. The steering unit 1 supports a cleaning unit 31. Therefore, if the steering unit 1 is supported only by the steering shaft 21, the load on the steering shaft 21 is increased due to the weight of the steering unit 1 and the cleaning unit 31, and malfunction of the steering unit 1 is likely to occur. Therefore, the operation of the steering unit 1 can be made difficult to occur by supporting the cleaning unit 31 on the apparatus main body 90a and reducing the load on the steering shaft 21.

[Toner outlet]
As can be understood with reference to FIGS. 2, 8, and 9, the cleaning container 28 is provided with a toner discharge port 40 for discharging the collected toner in the cleaning container 28 (within the storage container). The toner discharge port 40 is disposed at a position including a vertical plane F (see FIG. 7) that passes through the swing center of the steering roller 2 with respect to the rotation axis direction of the steering roller 2. Since the center of swinging of the steering roller 2 is the steering shaft 21, the vertical plane F includes the steering axis J. In the case of this embodiment, as already described, since the steering shaft 21 is provided at the center in the rotational axis direction of the steering roller 2, the toner discharge port 40 is located at the center in the longitudinal direction of the cleaning container 28 (the rotation of the steering roller 2). Axis direction center). Further, as shown in FIG. 9, the toner discharge port 40 is disposed such that the discharge port center O coincides with the vertical plane F in the longitudinal direction of the cleaning container 28.

  As shown in FIGS. 2 and 8, the toner discharge port 40 is provided with a shutter member 32 that opens and closes the toner discharge port 40. The shutter member 32 is configured to move between an open position and a shielding position. The shutter member 32 moves to a shielding position when the belt unit 100 is detached from the apparatus main body 90a to seal the toner discharge port 40, and moves to an open position when the belt unit 100 is attached to the apparatus main body 90a to discharge toner. The outlet 40 is opened.

  Further, as shown in FIG. 8, a gap is formed between the toner discharge port 40 and the toner receiving port 70a of the collection container 70 when the steering unit 1 is swung, and the collected toner is prevented from leaking from the gap. The sealing member 38 is provided. This is because a part of the toner discharge port 40 is overlapped in the gravity direction in a non-contact state with the toner receiving port 70a so that the toner discharging port 40 is not detached from the toner receiving port 70a of the collection container 70 in accordance with the swing of the steering unit 1. Because it is. The sealing member 38 is formed of an elastic member such as a sponge, and closes a gap between the toner discharge port 40 and the toner receiving port 70a. That is, the sealing member 38 is formed in a size that does not cause a gap when the cleaning unit 31 is farthest from the collection container 70. When the cleaning unit 31 approaches the collection container 70, it is crushed and deformed.

  In the case of the present embodiment, the steering unit 1 can swing within a swing angle range of ± 1.5 °. Here, in the conventional case where the toner discharge port 40 is provided not at the longitudinal center of the cleaning container 28 but at one end in the longitudinal direction, the inventors moved the steering unit 1 in the gravitational direction with reference to the toner discharge port 40. When the amount was measured, the amount of movement in the gravitational direction was ± 5 mm. And the fluctuation | variation of the crushing amount of the sealing member 38 in this case was about 10 mm. If the change in the crushing amount of the sealing member 38 is large, it is necessary to form the sealing member 38 larger (higher) accordingly. However, this causes the malfunction of the steering unit 1. In the case of a sealing member 38 such as a sponge, when the sealing member 38 is enlarged, the shape is difficult to return, and as a result, a gap is likely to be generated. Furthermore, in order to secure a space for installing the sealing member 38, the toner discharge port 40 and the toner receiving port 70a must be formed large, which is contrary to the recent demand for downsizing of the apparatus. Therefore, it is difficult to employ a large sealing member 38.

  On the other hand, in the case of this embodiment, the fluctuation | variation of the crushing amount of the sealing member 38 was about 0.6 mm. Therefore, the size (height) of the sealing member 38 is made smaller than the conventional one. Further, it was found that the reaction force of the sealing member 38 can be reduced to 0.3 / 5 times and the action distance from the steering shaft 21 to the force application point can be reduced to 10/170 times compared to the conventional case. That is, the moment load of steering by the sealing member 38 is suppressed to about 1/280. As described above, in the case of the present embodiment, the position variation in the direction of gravity with respect to the toner receiving port 70a of the toner discharge port 40 is small, and the load applied to the steering unit 1 during the steering operation can be reduced. hard.

  As described above, in the present embodiment, with respect to the steering unit 1 in which the cleaning unit 31 is integrated, the toner discharge port 40 is provided at a position including the vertical surface F passing through the swing center (the steering shaft 21) of the steering roller 2. It is done. In this case, even if the steering unit 1 swings, the position variation in the direction of gravity with respect to the collection container 70 (specifically, the toner receiving port 70a) of the toner discharge port 40 can be reduced, so that the sealing member 38 is formed smaller than the conventional one. can do. Even if the sealing member 38 is formed to be smaller than the conventional one, a gap is not formed between the recovery unit 70 and the recovered toner when the steering unit 1 is swung. In addition to this, the load applied to the steering unit 1 during the steering operation is reduced, and as a result, it is difficult to cause malfunctions in the steering operation.

<Second embodiment>
A second embodiment will be described with reference to FIGS. 10 to 12. Compared with the first embodiment described above, the belt unit 100A of the second embodiment is that the steering unit 1A is not an automatic alignment type, and the arrangement position of the steering shaft 21 and the toner discharge port 40 is the one end side of the steering unit 1A. The point is greatly different. Therefore, regarding the belt unit 100A of the second embodiment, the same configurations as those of the above-described first embodiment are denoted by the same reference numerals, the description thereof is omitted, and the above-described differences are mainly described.

[Intermediate transfer belt unit]
A belt unit 100A according to a second embodiment will be described with reference to FIGS. As shown in FIG. 10, the belt unit 100A of this embodiment is an external drive alignment type in which the steering unit 1A is swung by an external drive unit 200 such as a motor. The drive unit 200 as the swinging unit is controlled by the control unit 300 as the control unit. The driving unit 200 and the control unit 300 are separately provided in the apparatus main body 90a (see FIG. 1) without being integrated with the belt unit 100A. The drive unit 200 and the steering unit 1A are connected via a cam or gear (not shown) so that driving force is transmitted from the drive unit 200 to the steering unit 1A.

  The belt unit 100A is provided with a sensor 39 that reads the position of the end of the intermediate transfer belt 101 (the position in the width direction intersecting the rotation axis direction of the steering roller 2). The control unit 300 controls the drive unit 200 based on the position of the end portion (belt end portion) of the intermediate transfer belt 101 read by the sensor 39 as detection means. The drive unit 200 is controlled by the control unit 300, and swings the steering unit 1A so as to adjust the steering angle of the steering roller 2 with respect to the secondary transfer inner roller 110. In this way, the intermediate transfer belt 101 is moved in the width direction in response to the stepless change of the steering angle of the steering roller 2 with respect to the secondary transfer inner roller 110. That is, “belt deviation” is corrected.

[Steering unit]
As shown in FIGS. 10 and 11, the steering unit 21 of the present embodiment is provided with a steering shaft 21 on one end side in the width direction of the steering roller 2. In this case, since the steering unit 1A swings about the steering axis J as a swing center, the amount of fluctuation at the time of swinging is larger on the other end side than on one end side where the steering shaft 21 is provided. That is, the steering unit 1A is provided so as to be able to swing so that the other end side is largely changed in the direction of gravity rather than the one end side where the steering shaft 21 is provided.

[Cleaning unit]
A cleaning unit 31A is integrated with the belt unit 100A. The cleaning unit 31A is provided on the opposite side of the steering unit 1A (more specifically, the steering roller 2) across the intermediate transfer belt 101 so as to be able to swing integrally with the steering unit 1A. The cleaning unit 31A includes a cleaning blade (not shown) and a cleaning container 28.

[Toner outlet]
The cleaning container 28 is provided with a toner discharge port 40 for discharging the collected toner in the container. As shown in FIG. 12, the toner discharge port 40 is disposed at a position including a vertical surface F passing through the swing center of the steering roller 2 with respect to the rotational axis direction of the steering roller 2 (see FIG. 10). As described above, since the swing center of the steering roller 2 is the steering shaft 21, the vertical plane F includes the steering axis J. In the present embodiment, as already described, since the steering shaft 21 is provided on one end side in the rotation axis direction of the steering roller 2, the toner discharge port 40 is connected to one end portion of the cleaning container 28 (the steering roller 2). (End part in the rotation axis direction). As shown in FIG. 11, a gap is formed between the toner outlet 40 and the toner receiving port 70a of the collection container 70 when the steering unit 1A is swung, and the collected toner is prevented from leaking from the gap. A stop member 38 is provided. Further, a shutter member 32 that opens and closes the toner discharge port 40 is provided.

  In the present embodiment, the collected toner scraped off by a cleaning blade (not shown) is accommodated in the cleaning container 28. The collected toner in the cleaning container 28 is transported toward the toner discharge port 40 by the transport screw 36 (see FIG. 11). The collected toner that has reached the toner discharge port 40 during conveyance is discharged from the toner discharge port 40 to the collection container 70.

  As described above, also in the second embodiment, the vertical surface F through which the toner discharge port 40 passes through the swing center (the steering shaft 21) of the steering roller 2 is related to the swingable steering unit 1A that is integrated with the cleaning unit 31A. It is provided in the position containing. The major difference between the second embodiment described above and the first embodiment is mainly the position of the swing center (steering shaft 21) of the steering roller 2. In the case of the second embodiment, the toner discharge port 40 is provided on one end side of the cleaning container 28. Even in this case, the same effect as in the case of the first embodiment described above can be obtained. That is, since the positional variation in the gravity direction of the toner discharge port 40 with respect to the collection container 70 can be reduced, even if the sealing member 38 is formed smaller than the conventional one, the gap between the toner discharge port 40 and the collection container 70 when the steering unit 1A is swung. There is no gap and the collected toner does not leak. Further, as a result of reducing the load applied to the steering unit 1A during the steering operation, it is difficult for the steering operation to malfunction.

DESCRIPTION OF SYMBOLS 1 (1A) ... Steering mechanism (steering unit), 2 ... 2nd roller (steering roller), 3 ... Fixed member (sliding ring member), 7 ... Support member (oscillating plate), 21 ... Rotating shaft (steering) (Shaft), 28 ... receiving container (cleaning container), 28 a ... engaging portion, 31 (31 A) ... cleaning unit, 36 ... conveying member (conveying screw), 38 ... sealing member, 39 ... detecting means (sensor), 40 DESCRIPTION OF SYMBOLS ... Discharge port (toner discharge port), 70 ... Collection container, 70a ... Receiving port (toner receiving port), 90 ... Image forming apparatus, 90a ... Device main body, 100 (100A) ... Intermediate transfer belt unit, 101 ... Belt (intermediate) Transfer belt), 102 ... Cleaning member (cleaning blade), 110 ... First roller (secondary transfer inner roller), 200 ... Swing means (drive unit), 3 0 ... control means (the control unit)

Claims (7)

An endless belt that carries toner and rotates;
A first roller that rotates by stretching the belt;
A second roller that rotates by stretching the belt together with the first roller;
A steering mechanism that swings the second roller with respect to the first roller and moves the belt in the rotational axis direction of the second roller;
A cleaning member for removing toner on the belt, a storage container for storing the toner removed from the belt, and a discharge port provided in the storage container for discharging the toner in the storage container; A cleaning unit swinging integrally with the second roller;
A collection container disposed below the discharge port in the direction of gravity and having a receiving port connected to the discharge port and receiving toner discharged from the discharge port;
An elastic sealing member provided so as to close a gap between the discharge port and the receiving port;
The discharge port is disposed at a position including a vertical plane passing through the swing center of the second roller with respect to the rotation axis direction of the second roller.
An image forming apparatus. The discharge port is disposed so that the center of the rotation axis direction of the second roller coincides with the vertical plane.
The image forming apparatus according to claim 1. The steering mechanism is provided with a rotation shaft at the center in the rotation axis direction of the second roller,
The discharge port is disposed at the center of the rotation direction of the second roller.
The image forming apparatus according to claim 1, wherein: The steering mechanism supports a fixed member provided so as not to rotate at both ends in the rotation axis direction of the second roller, and supports the second roller and the fixed member so as to be swingable around the rotation shaft. A supporting member
The image forming apparatus according to claim 3. The container has an engaging portion that is swingably engaged with the apparatus side at the center in the rotation axis direction of the second roller.
The image forming apparatus according to claim 4. Rocking means for rocking the second roller;
Detecting means for detecting a position in a width direction intersecting a rotation axis direction of the second roller of the belt end;
Control means for controlling the swinging means based on the position of the belt end detected by the detecting means,
The steering mechanism is provided with a rotation shaft at one of end portions in the rotation axis direction of the second roller,
The discharge port is disposed at a rotation axis direction end portion of the second roller provided with the rotation shaft.
The image forming apparatus according to claim 1, wherein: The storage container includes a transport member that transports the stored toner toward the discharge port.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.

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