Belt conveyance device and image forming device

Abstract

To suppress a recovered material from leaking from an end in a longer direction of a sheet-like second cleaning member, and suppress contact pressure between the second cleaning member and a belt at the end from rising.SOLUTION: Provided is a belt conveyance device 200 having an endless belt 101 and a cleaning device 180, the cleaning device 180 having a blade-like first cleaning member 181, a sheet-like second cleaning member 185, an end seal 190, and a container 180a. The container 180a has a fixing part 186b extending in a longer direction and fixing at least a part thereof in the longer direction on a base end side in a shorter direction of the second cleaning member 185, and the second cleaning member 185 is constructed such that at least part thereof on a tip 185a side in the shorter direction is provided so as to overlap at least a part of the end seal 190 from the belt 101 side, outside an end of the fixing part 186b in the longer direction, respectively on both end sides in the longer direction.SELECTED DRAWING: Figure 16

Description

[Technical field]

[0001] The present invention relates to a belt conveying device that can be used in an image forming apparatus such as a copying machine, printer, or facsimile machine using an electrophotographic or electrostatic recording method, or a multifunction machine having multiple functions among these, and to an image forming apparatus equipped with the belt conveying device. [Background technology]

[0002] Conventionally, in image forming apparatuses such as copying machines using an electrophotographic method, a belt conveying device equipped with an endless belt (hereinafter also simply referred to as "belt") as a photosensitive body or intermediate transfer body is used. In addition, the belt conveying device may be equipped with a cleaning device that removes (cleans) residual toner adhering to the surface of the belt after the toner image on the belt is transferred to the transfer body. This cleaning device has a cleaning member that contacts the surface of the belt to remove residual toner. In addition to toner, this cleaning member also cleans external additives added to the toner and paper powder peeled off from the recording material that are adhering to the surface of the belt. As the cleaning member, a plate-shaped cleaning member made of a rubber material is often used. Hereinafter, this plate-shaped cleaning member (first cleaning member) is referred to as a "cleaning blade."

[0003] If the cleaning blade cannot sufficiently clean the additives and paper dust from the surface of the belt, transfer failures occur due to a drop in the charged potential of the belt surface, causing image defects. Also, if paper dust gets into the contact area between the cleaning blade and the belt, the paper dust can get caught in the contact area, causing toner to slip through the part where the paper dust is caught, resulting in poor cleaning.

[0004] Patent Document 1 proposes arranging a sheet-like cleaning member in the cleaning device that comes into contact with the surface of the belt to remove external additives and paper dust. Hereinafter, the sheet-like cleaning member (second cleaning member) is referred to as a "cleaning scraper." The cleaning scraper removes external additives and paper dust from the belt and stores the removed external additives and paper dust in a storage unit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2008-89770 A Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, in the cleaning device, a seal member is provided to prevent collected materials such as toner from leaking between the cleaning blade or cleaning scraper and the container or belt in which they are provided. In particular, end seals are often provided at the ends of the cleaning blade or cleaning scraper in the longitudinal direction (the direction along the width direction of the belt) to prevent collected materials from leaking from these ends.

[0007] In order to prevent the collected material from leaking from the longitudinal ends of the cleaning scraper, it is considered desirable to arrange the end seal so as to overlap the cleaning scraper in the longitudinal direction.

[0008] However, in this case, the end seal presses against the cleaning scraper, which may cause the contact pressure between the belt and the cleaning scraper to be higher at the longitudinal ends of the cleaning scraper than at the center, which may cause damage to the belt, such as scratches on the surface of the belt.

[0009] In addition, the belt conveying device may be equipped with a steering mechanism for correcting "belt deviation," a phenomenon in which the conveying position of the belt in the width direction of the belt deviates toward one of the ends (moving the belt in the opposite direction to the deviation). In this case, if the contact pressure at the end of the longitudinal direction of the cleaning scraper increases as described above, this may cause sliding resistance and hinder steering (correction of the belt deviation). This may cause "belt deviation," a phenomenon in which the conveying position of the belt in the width direction of the belt deviates too far toward one of the ends. This may be particularly noticeable when the belt conveying device is configured to have an autonomous steering mechanism that uses the force generated by the friction between the belt and a sliding member in contact with it for steering.

[0010] Therefore, an object of the present invention is to prevent the collected material from leaking from the longitudinal ends of the sheet-shaped second cleaning member, and to prevent an increase in contact pressure between the second cleaning member and the belt at those ends. [Means for solving the problem]

[0011] The above object is achieved by the belt conveying device and image forming device according to the present invention. In summary, a typical configuration of the present invention includes a circumferentially movable endless belt that is stretched around a plurality of tension rollers and carries a toner image on its surface, and a cleaning device that extends in a longitudinal direction along a width direction that is substantially perpendicular to the moving direction of the surface of the belt and cleans the surface of the belt, the cleaning device including a blade-shaped first cleaning member that extends in the longitudinal direction and contacts the surface of the belt, a sheet-shaped second cleaning member that extends in the longitudinal direction and contacts the surface of the belt downstream of a contact portion between the first cleaning member and the surface of the belt in the moving direction, end seals that are provided on both ends of the first cleaning member in the longitudinal direction and are arranged to contact the ends of the first cleaning member and the surface of the belt, and a cleaning device that includes a cleaning member that is provided on the first cleaning member, the second cleaning member, and a cleaning member that is provided on the first cleaning member, the second cleaning member, and a cleaning member that is provided on the second cleaning member. and a container for holding the end seal, wherein at least a portion of the tip side of the second cleaning member in a short direction intersecting the longitudinal direction abuts against the surface of the belt, and at least a portion of the longitudinal direction of a base end side in the short direction located downstream of the tip side in the moving direction is fixed to the container, the container has a fixing portion extending in the longitudinal direction and fixing at least a portion of the longitudinal direction of the base end side in the short direction of the second cleaning member, and the second cleaning member is arranged on each of both end sides in the longitudinal direction, outside the ends of the fixing portion in the longitudinal direction, so that at least a portion of the tip side in the short direction overlaps with at least a portion of the end seal from the belt side.

[0012] Another representative configuration of the present invention is an image forming apparatus comprising the above-mentioned belt conveying device of the present invention and an image forming section that forms a toner image on the surface of the belt. Effect of the Invention

[0013] According to the present invention, it is possible to prevent collected matter from leaking from the longitudinal ends of the sheet-shaped second cleaning member, and to prevent an increase in contact pressure between the second cleaning member and the belt at the ends. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic cross-sectional view of an image forming apparatus. [Diagram 2] FIG. 2 is a schematic cross-sectional view of an intermediate transfer unit. [Diagram 3] FIG. 2 is a perspective view of an autonomous steering mechanism. [Figure 4] 1A and 1B are schematic diagrams for explaining the operation of an autonomous steering mechanism. [Diagram 5] FIG. 2 is a schematic cross-sectional view of an intermediate transfer belt. [Figure 6] FIG. 2 is a cross-sectional view of the belt cleaning device and its vicinity. [Figure 7] FIG. 2 is a side view of the belt cleaning device. [Figure 8] FIG. 4 is a schematic side view for explaining the positional relationship between a cleaning scraper and an end seal in the embodiment. [Figure 9] FIG. 4 is a schematic side view for explaining the positional relationship between a cleaning scraper and an end seal in the embodiment. [Figure 10] 5A and 5B are schematic diagrams for explaining the frictional force between the intermediate transfer belt and the cleaning blade. [Figure 11] 5A and 5B are schematic diagrams for explaining the frictional force between the intermediate transfer belt and the cleaning blade. [Figure 12] FIG. 4 is a side view of the belt cleaning device for explaining the relationship between the end toner passing through and the configuration of the embodiment. [Figure 13] 5A and 5B are schematic side and cross-sectional views for explaining the positional relationship between a cleaning scraper and an end of an intermediate transfer belt. [Figure 14] 3A and 3B are schematic side and cross-sectional views for explaining the positional relationship between a cleaning scraper and an end of an intermediate transfer belt in the first embodiment. [Figure 15] 11A and 11B are schematic side and cross-sectional views for explaining the positional relationship between a cleaning scraper and an end of an intermediate transfer belt in a second embodiment. [Figure 16] FIG. 11 is a side view of a belt cleaning device in a third embodiment. [Figure 17] FIG. 11 is a perspective view showing a second accommodating member of a belt cleaning device in a third embodiment. [Figure 18] FIG. 11 is a perspective view showing a second housing portion of a belt cleaning device in a third embodiment. [Figure 19] FIG. 11 is a side view of the belt cleaning device for explaining the effect of the longitudinal length of the cleaning scraper. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the image forming apparatus according to the present invention will be described in more detail with reference to the drawings.

[0016] [Example 1] <Overall Configuration and Operation of Image Forming Apparatus> 1 is a schematic cross-sectional view of an image forming apparatus 100 according to this embodiment. The image forming apparatus 100 according to this embodiment is a tandem-type color digital printer of an intermediate transfer system equipped with four image forming units 109Y, 109M, 109C, and 109K along an intermediate transfer belt 101. This image forming apparatus 100 can form full-color images using an electrophotographic system.

[0017] The four image forming units 109Y, 109M, 109C, and 109K form images of the colors yellow (Y), magenta (M), cyan (C), and black (K), respectively. Elements having the same or corresponding functions or configurations provided for each color may be generally described by omitting the Y, M, C, or K at the end of the reference numeral indicating that the element is for any one of the colors. In this embodiment, the image forming units 109 (109Y, 109M, 109C, and 109K) are configured to include photosensitive drums 103 (103Y, 103M, 103C, and 103K), charging rollers 104 (104Y, 104M, 104C, and 104K), exposure devices 105 (105Y, 105M, 105C, and 105K), and drum cleaning devices 108 (108Y, 108M, 108C, and 108K), which will be described later.

[0018] The photosensitive drum 103, which is a rotatable drum-type (cylindrical) photosensitive body (electrophotographic photosensitive body) serving as an image carrier, is rotated in the direction of arrow R in the figure (clockwise direction in FIG. 1) by a driving motor (not shown) serving as a driving means. The surface of the rotating photosensitive drum 103 is uniformly charged to a predetermined potential of a predetermined polarity (negative polarity in this embodiment) by a charging roller 104, which is a roller-type charging member serving as a charging means. The charged surface of the photosensitive drum 103 is scanned and exposed by an exposure device (laser scanner) 105 serving as an exposure means, and an electrostatic latent image (electrostatic image) is formed on the photosensitive drum 103. The exposure device 105 of each image forming unit 109 receives image signals of yellow, magenta, cyan, and black components, respectively, and irradiates the surface of the photosensitive drum 103 with laser light in accordance with the image signals, neutralizing the charges on the surface of the photosensitive drum 103 to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 103 is developed (visualized) by supplying toner as a developer by the developing device 106 as a developing means, and a toner image (toner image, developer image) is formed on the photosensitive drum 103. The developing device 106 of each image forming unit 109 develops the electrostatic latent image on the photosensitive drum 103 with yellow, magenta, cyan, and black toner, respectively. In this embodiment, the developing device 106 attaches toner charged with the same polarity as the charge polarity of the photosensitive drum 103 (negative polarity in this embodiment) to the exposed portion (image portion) on the photosensitive drum 103, which has been uniformly charged and then exposed to light to reduce the absolute value of the potential (reverse development method). In this embodiment, the normal charge polarity of the toner, which is the main charge polarity of the toner during development, is negative polarity.

[0019] An intermediate transfer unit 200 is disposed facing the four photosensitive drums 103. The intermediate transfer unit 200 has an intermediate transfer belt 101, which is an intermediate transfer body formed of an endless belt. The intermediate transfer belt 101 rotates (moves orbitally, circulates) in the direction of arrow V in the figure (counterclockwise in FIG. 1) by a driving force transmitted when a driving roller 110 is rotated and driven by a driving motor (not shown) serving as a driving means. Primary transfer rollers 107Y, 107M, 107C, and 107K, which are roller-type primary transfer members serving as primary transfer means, are disposed on the inner circumferential surface side of the intermediate transfer belt 101 in correspondence with the photosensitive drums 103Y, 103M, 103C, and 103K. The primary transfer roller 107 presses the intermediate transfer belt 101 toward the photosensitive drum 103 to form a primary transfer portion (primary transfer nip) T1 (T1Y, T1M, T1C, T1K) where the photosensitive drum 103 and the intermediate transfer belt 101 come into contact. The toner image formed on each photosensitive drum 103 is primarily transferred onto the rotating intermediate transfer belt 101 as a transfer target by the action of the primary transfer roller 107 at the primary transfer portion T1. During the primary transfer, a primary transfer voltage (primary transfer bias) of a polarity opposite to the normal charging polarity of the toner (positive polarity in this embodiment) is applied to the primary transfer roller 107. For example, when a full-color image is formed, the toner images of each color of yellow, magenta, cyan, and black formed on each photosensitive drum 103 are sequentially primarily transferred onto the intermediate transfer belt 101 so as to be superimposed on each other. As a result, a multiple toner image for a full-color image is formed on the intermediate transfer belt 101. Toner remaining on the photosensitive drum 103 after the primary transfer (primary transfer residual toner, residual toner) is removed from the photosensitive drum 103 and collected by a drum cleaning device 108, which is a cleaning device constituting a photosensitive body cleaning means.

[0020] On the other hand, a recording material P such as paper fed (discharged) from a cassette paper feed unit 120 as a recording material storage unit by a paper feed roller 121 as a feeding member is sent toward a registration roller 122 as a conveying member. Furthermore, the recording material P is sent to a secondary transfer unit T2 by the registration roller 122 in synchronization with the toner image on the intermediate transfer belt 101. On the outer peripheral surface side of the intermediate transfer belt 101, a secondary transfer outer roller 111 which is a roller-type secondary transfer member as a secondary transfer means is disposed at a position facing the drive roller 110. The secondary transfer outer roller 111 is pressed toward the drive roller 110 and abuts against the drive roller 110 via the intermediate transfer belt 101, forming a secondary transfer unit (secondary transfer nip) T2 where the intermediate transfer belt 101 and the secondary transfer outer roller 111 abut against each other. The toner image on the intermediate transfer belt 101 is secondarily transferred at the secondary transfer portion T2 by the action of the secondary transfer inner roller 110 and the secondary transfer outer roller 111 onto a recording material P as a transfer target material that is sandwiched and transported between the intermediate transfer belt 101 and the secondary transfer outer roller 111. During the secondary transfer, a secondary transfer voltage (secondary transfer bias) of a polarity opposite to the normal charging polarity of the toner (positive polarity in this embodiment) is applied to the secondary transfer outer roller 111. The drive roller 110 that functions as the secondary transfer inner roller is connected to a ground potential (electrically grounded).

[0021] The recording material P onto which the toner image has been transferred is sent to a fixing device 130 as a fixing means. The fixing device 130 applies heat and pressure to the recording material P carrying the unfixed toner image, thereby fixing (melting and bonding) the toner image onto the recording material P. Thereafter, the recording material P onto which the toner image has been fixed is discharged (output) to the outside (outside the machine) of the device body 100a of the image forming apparatus 100 (hereinafter also simply referred to as the "device body").

[0022] Furthermore, on the intermediate transfer belt 101 after the secondary transfer, there are deposits such as toner that remains without being transferred to the recording material P at the secondary transfer portion T2 (secondary transfer residual toner, residual toner) and paper powder that has adhered to the intermediate transfer belt 101 at the secondary transfer portion T2. ​​These deposits are removed from the intermediate transfer belt 101 and collected by a belt cleaning device 180, which is a cleaning device that constitutes a belt cleaning means.

[0023] The collected matter, such as the toner collected by the drum cleaning device 108 and the belt cleaning device 180, is transported by a transport member provided in each cleaning device and discharged from each cleaning device. The collected matter is sent to a collected toner container (not shown) arranged in the device main body 100a via a collected toner transport path (not shown) provided in the device main body 100a, and is stored in the collected toner container.

[0024] The intermediate transfer unit 200 as the belt conveying device in this embodiment, and the belt cleaning device 180 provided therein will be described in more detail later.

[0025] <Intermediate transfer unit> 2 is a schematic cross-sectional view of the intermediate transfer unit 200 in this embodiment (also showing the photosensitive drum 103 and the secondary transfer outer roller 111). FIGS. 2(a), (b), and (c) each show different tension configurations of the intermediate transfer belt 101, which will be described later.

[0026] The intermediate transfer unit 200 is a belt conveying device having an intermediate transfer belt 101 that is tensioned by a plurality of tension rollers and rotated and conveyed. The intermediate transfer belt 101 is an endless belt member formed by using a resin such as polyimide. The intermediate transfer belt 101 is tensioned by a plurality of tension rollers, including a drive roller 110, a steering roller 112, a first auxiliary roller 113, and a second auxiliary roller 114, which are rotatably supported by a part of a frame 201 as a frame member (support). In addition, on the inner peripheral surface side of the intermediate transfer belt 101, each of the primary transfer rollers 107 that are rotatably supported by a part of the frame 201 is disposed. In addition, on the outer peripheral surface side of the intermediate transfer belt 101, a belt cleaning device 180 is provided at a position facing the steering roller 112. In this embodiment, the belt cleaning device 180 is positioned on the rotation axis of the tension roller 112 and held by the frame 201. The frame 201, the multiple tension rollers 110, 112, 113, and 114, the primary transfer rollers 107, and the intermediate transfer belt 101 are assembled together to form an intermediate transfer unit 200. In this embodiment, the intermediate transfer unit 200 is detachable from the apparatus main body 100a.

[0027] The driving roller 110 has a function of driving the intermediate transfer belt 101, and also serves as a secondary transfer inner roller forming the secondary transfer portion T2. ​​The steering roller 112 constitutes an autonomous steering mechanism 210 (FIG. 3) described later, and also serves as a tension roller that applies tension to the intermediate transfer belt 101. The steering roller 112 is urged by a compression spring 213, which is an urging member as an urging means, so as to press the intermediate transfer belt 101 from the inner peripheral surface side toward the outer peripheral surface side, thereby applying tension to the intermediate transfer belt 101. The first auxiliary roller 113 and the second auxiliary roller 114 form a surface of the intermediate transfer belt 101 onto which a toner image is transferred from the photosensitive drum 103. The tension rollers other than the driving roller 110 and each primary transfer roller 107 are rotated following the rotation of the intermediate transfer belt 101. The outer secondary transfer roller 111 may be configured to rotate in accordance with the rotation of the intermediate transfer belt 101, or may be configured to be driven to rotate.

[0028] During color image formation, as shown in FIG. 2(a), each primary transfer roller 107 forms a primary transfer portion T1 with each photosensitive drum 103 via the intermediate transfer belt 101. Then, each primary transfer roller 107 transfers the yellow, magenta, cyan, and black toner images from each photosensitive drum 103 onto the intermediate transfer belt 101 in a superimposed manner. On the other hand, during monochrome image formation, as shown in FIG. 2(b), the yellow, magenta, and cyan primary transfer rollers 107Y, 107M, and 107C and the first auxiliary roller 113 are moved in a direction away from the photosensitive drum 103 (upward in the figure) by a lifting mechanism (not shown). This causes the intermediate transfer belt 101 and the yellow, magenta, and cyan photosensitive drums 103Y, 103M, and 103C to be separated from each other. Also, the yellow, magenta, and cyan photosensitive drums 103Y, 103M, and 103C are stopped. Then, the black primary transfer roller 107K forming the primary transfer portion T1 via the intermediate transfer belt 101 transfers the black toner image from the photosensitive drum 103K to the intermediate transfer belt 101. In addition, in a standby state in which the image forming apparatus 100 is waiting for a print instruction, the lifting mechanism further moves the black primary transfer roller 107K and the second auxiliary roller 114 in a direction away from the photosensitive drum 103 (upward in the figure), as shown in FIG. 2(c). As a result, the intermediate transfer belt 101 is completely separated from the four photosensitive drums 103.

[0029] <Autonomous steering mechanism> Fig. 3 is a perspective view showing an autonomous steering mechanism (steering unit) 210 provided in the intermediate transfer unit 200 in this embodiment. Fig. 4 is a schematic diagram for explaining the operation of the autonomous steering mechanism 210.

[0030] The steering roller 112 is supported by a steering roller support member 211 constituting an autonomous steering mechanism 210 at both ends in the axial direction (rotation axis direction) so as to rotate following the rotation of the intermediate transfer belt 101. A sliding ring portion 212 is provided at both ends in the axial direction of the steering roller 112 as a sliding member whose rotation is restricted. In this embodiment, the sliding ring portion 212 includes a bearing 212a and also serves as a bearing member for the steering roller 112. The sliding ring portion (bearing member) 212 is supported by the steering roller support member 211 so as to be slidable in the direction of arrow X in FIG. 3 relative to the steering roller support member 211. The arrow X direction is a direction from the inner peripheral surface side toward the outer peripheral surface side of the intermediate transfer belt 101 and a direction along the opposite direction. As a result, the steering roller 112 is configured to be biased toward the intermediate transfer belt 101 by a compression spring 213 arranged between the steering roller support member 211 and the sliding ring portion 212. Further, the sliding ring portion 212 is provided adjacent to an end portion of the steering roller 112 in the axial direction. Further, the steering roller support member 211 is supported by the frame 201 via a rotation shaft 214 so as to be tiltable relative to the frame 201. The steering roller support member 211 is supported by the steering roller support member 211 via the rotation shaft 214 so as to be tiltable around an axis 214a that is approximately perpendicular to the axis (rotation axis) 112a of the steering roller 112, relative to the frame 201. As a result, the axis 112a of the steering roller 112 is tiltable relative to the axis of another tension roller, for example, the drive roller 110.

[0031] In the state shown in FIG. 4A, the intermediate transfer belt 101 is stretched in a well-balanced manner with respect to the center of the axial direction of the steering roller 112. In this embodiment, in this state, both ends of the intermediate transfer belt 101 in the width direction (the direction substantially perpendicular to the moving direction of the surface of the intermediate transfer belt 101, i.e., the direction substantially parallel to the axial direction of the steering roller 112) are engaged with the sliding ring portion 212. When the intermediate transfer belt 101 shifts from the state shown in FIG. 4A to the left (one axial direction) as shown in FIG. 4B, a frictional force is generated between the intermediate transfer belt 101 and the sliding ring portion 212 at both ends. At this time, the engagement width between the intermediate transfer belt 101 and the sliding ring portion 212 at both ends differs between the left and right, and the frictional force on the left side (one axial side) with the larger engagement width becomes larger than that on the right side (the other axial side), so that the steering roller 112 tilts in a direction lowering the left side. As a result, the alignment between the drive roller 110 and the steering roller 112 is lost, and the intermediate transfer belt 101 shifts to the right at the portion where it is wound around the steering roller 112, correcting the shift in the position of the intermediate transfer belt 101. Also, when the intermediate transfer belt 101 shifts to the right (the other axial direction) as shown in FIG. 4(c), the frictional force between the intermediate transfer belt 101 and the sliding ring portion 212 on the right side (the other axial side) increases, and the steering roller 112 tilts in a direction lowering the right side. As a result, the intermediate transfer belt 101 shifts to the left (one axial side) at the portion where it is wound around the steering roller 112, correcting the shift in the position of the intermediate transfer belt 101.

[0032] In the intermediate transfer unit 200, when the intermediate transfer belt 101 is rotated, the intermediate transfer belt 101 usually deviates in one direction due to the influence of misalignment of the tension roller and slight distribution of roller diameter in the longitudinal direction (axial direction) of the roller. However, in response to this, the balance of frictional forces between the intermediate transfer belt 101 and the sliding ring portions 212 at both ends gradually changes, causing the steering roller 112 to tilt. As a result, the speed at which the intermediate transfer belt 101 decelerates gradually, and the steering roller 112 converges to a tilted posture where the deviation of the intermediate transfer belt 101 is balanced.

[0033] <Intermediate transfer belt> FIG. 5 is a schematic cross-sectional view of the intermediate transfer belt 101 in this embodiment (showing a cross-section along the width direction of the intermediate transfer belt 101).

[0034] In this embodiment, the intermediate transfer belt 101 is configured to have at least two layers, a base layer 74 and a surface layer 75, as shown in FIG. 5. In this embodiment, the base layer 74 is formed of a semiconductive film in which a conductive agent is contained in a resin such as polyimide. In addition, in this embodiment, the surface layer 75 is a coating layer formed by coating with an acrylic resin or the like. Furthermore, in this embodiment, at both ends of the surface layer 75 in the width direction (width direction of the intermediate transfer belt 101), a reinforcing tape 76 is provided on the surface layer 75 as a reinforcing member. In this embodiment, the reinforcing tape 76 is adhered and fixed on the surface layer 75. Note that the both ends of the surface layer 75 are not necessarily limited to including the edges of the surface layer 75. They may be regions that are inside the edges of the surface layer 75 and are closer to the ends than the center in the width direction of the intermediate transfer belt 101. That is, the outer edges of the reinforcing tape 76 may be disposed inside the edges of the surface layer 75 in the width direction of the intermediate transfer belt 101. The reinforcing tape 76 may be arranged so as to include the edges of the surface layer 75 at both widthwise ends of the surface layer 75, or may be arranged so as to include the edge of the surface layer 75 at only one of the ends.

[0035] In this embodiment, the reinforcing tape 76 is adhered and fixed to the entire circumference of the intermediate transfer belt 101 at both ends in the width direction of the intermediate transfer belt 101 in order to improve the durability of the intermediate transfer belt 101. The reinforcing tape 76 is disposed outside both ends of the contact area of ​​the intermediate transfer belt 101 with the cleaning blade 181 described later in the width direction of the intermediate transfer belt 101. The material of the reinforcing tape 76 may be, for example, a polyester film base layer on which an acrylic adhesive is laminated as an adhesive layer, but is not limited thereto. In this embodiment, the reinforcing tape 76 has a thickness of 0.08 mm and a width of 5 mm. However, the thickness and width of the reinforcing tape 76 are not limited thereto.

[0036] As described above, in this embodiment, the surface layer 75 of acrylic resin or the like is uniformly coated on the base layer 74 of the intermediate transfer belt 101. In addition, in this embodiment, the surface layer 75 is polished so that the surface layer 75 has sufficient surface roughness (ten-point average roughness Rz: JIS B0601 1994). This makes it possible to prevent stress concentration from occurring in the intermediate transfer belt 101 and ensure sufficient adhesive strength between the intermediate transfer belt 101 and the reinforcing tape 76.

[0037] <Belt cleaning device> Fig. 6 is a cross-sectional view of the vicinity of the belt cleaning device 180 in this embodiment (showing a cross section substantially perpendicular to the width direction of the intermediate transfer belt 101). Fig. 7 is a side view of the belt cleaning device 180 in this embodiment as seen from the intermediate transfer belt 101 side (illustration of a cleaning scraper 185 described later is omitted).

[0038] The belt cleaning device 180 is a cleaning device that extends along (in this embodiment, approximately parallel to) the width direction that is approximately perpendicular to the moving direction of the surface of the intermediate transfer belt 101 and cleans the surface of the intermediate transfer belt 101.

[0039] In this case, with respect to the belt cleaning device 180 and its elements, the direction approximately parallel to the width direction (approximately parallel to the longitudinal direction of the cleaning blade 181 described later) that is approximately perpendicular to the moving direction of the surface of the intermediate transfer belt 101 is defined as the longitudinal direction. Also, the direction that intersects with this longitudinal direction (approximately perpendicular in this embodiment) is defined as the transverse direction. Also, with respect to the image forming apparatus 100 and its elements, the front side of the paper surface of FIG. 1 is defined as the "front side", and the rear side of the paper surface of FIG. 1 is defined as the "rear side". The direction that connects the front side and the rear side and is approximately perpendicular to the paper surface of FIG. 1 is defined as approximately parallel to the axial direction of the photosensitive drum 103 and the tension roller of the intermediate transfer belt 101. Also, with respect to the image forming apparatus 100 and its elements, the up and down refer to the up and down in the direction of gravity (vertical direction), but does not mean only directly above and directly below, but also includes the upper and lower sides of a horizontal plane that passes through the element or position of interest. In this embodiment, the configurations of the longitudinal ends of the cleaning blade 181, cleaning scraper 185, first housing member 184, second housing member 186, etc., which will be described later, and the configurations of sealing members such as the end seal 190 and scraper sealing seal 189, etc., are substantially symmetrical with respect to approximately the center in the width direction of the intermediate transfer belt 101 (the nominal center when no deviation occurs). Therefore, these configurations may be described by illustrating only one longitudinal end side as appropriate.

[0040] As shown in FIG. 6, the belt cleaning device 180 has a cleaning blade 181 as a first cleaning member, a fixed metal plate 182 as a support member, a conveying screw 183 as a conveying member, and a first storage member (toner storage member) 184. The first storage member 184 holds the cleaning blade 181, the fixed metal plate 182, the conveying screw 183, and the like. The first storage member 184 also holds collected matter (removed matter) such as toner (which may contain external additives and paper powder; the same applies below) scraped off from the intermediate transfer belt 101 by the cleaning blade 181. The belt cleaning device 180 also has a cleaning scraper 185 as a second cleaning member disposed downstream of the cleaning blade 181 in the moving direction V of the surface of the intermediate transfer belt 101, and a second storage member (paper powder storage member) 186. The second storage member 186 holds the cleaning scraper 185. The second storage member 186 stores collected materials (removed materials) such as paper powder (which may contain toner and external additives; the same applies below) scraped off from the intermediate transfer belt 101 by the cleaning scraper 185. As will be described in detail later, the cleaning scraper 185 is fixed to a fixed portion (fixed seat) 186b provided on the second storage member 186. The region (the region of the fixed portion 186b) that holds the cleaning scraper 185 of the second storage member 186 in the longitudinal direction is defined as a fixed region F. In this embodiment, the first storage member 184 and the second storage member 186 are connected to form a cleaning container 180a as a housing of the belt cleaning device 180. The cleaning container 180a as a housing of the belt cleaning device 180 may be formed integrally with the portions that correspond to the first storage member 184 and the second storage member 186 in this embodiment.

[0041] The cleaning blade 181 is a plate-like member formed of an elastic body, having a predetermined length in the longitudinal direction (approximately parallel in this embodiment) arranged along the width direction of the intermediate transfer belt 101 and in the short direction approximately perpendicular to the longitudinal direction, and having a predetermined thickness. In this embodiment, the cleaning blade 181 is a plate-like member that is approximately rectangular in plan view. In this embodiment, the cleaning blade 181 is formed of urethane rubber, which is a rubber material serving as an elastic body. The cleaning blade 181 is disposed opposite the steering roller 112 via the intermediate transfer belt 101 at an angle that is a counter direction to the moving direction V of the surface of the intermediate transfer belt 101. In other words, the cleaning blade 181 is disposed so that a free end (tip) in the short direction is located upstream of the fixed end (base end) in the moving direction V of the surface of the intermediate transfer belt 101. As a result, the cleaning blade 181 is disposed so that the free end faces the upstream side in the moving direction V of the surface of the intermediate transfer belt 101. The cleaning blade 181 applies an external force to the steering roller 112 via the intermediate transfer belt 101 by bringing an edge portion of a free end portion in the short side direction into contact with the surface of the intermediate transfer belt 101. The cleaning blade 181 is made of, for example, urethane rubber having a JIS-A hardness of 77° and a thickness of 2 mm. The cleaning blade 181 has a fixed end portion in the short side direction fixed to a fixed metal plate 182. In this embodiment, the cleaning blade 181 is fixed to the fixed metal plate 182 by adhesion. The fixed metal plate 182 to which the cleaning blade 181 is fixed is fixed to the first housing member 184 by screws or the like and held therein.

[0042] The collected matter such as toner collected from the intermediate transfer belt 101 by the cleaning blade 181 is stored in a first storage section (collected toner storage section) 184a formed in the first storage member 184. A conveying screw 183 is disposed in the first storage section 184a. The conveying screw 183 conveys the collected matter such as toner in the first storage section 184a along the longitudinal direction toward one end (for example, the end on the front side) of the first storage member 184. The collected matter such as toner conveyed by the conveying screw 183 is discharged from an outlet (not shown) provided at the one end of the first storage member 184 and sent to a collected toner conveying path (not shown) provided in the apparatus main body 100a. The collected matter sent to this collected toner conveying path is conveyed to a collected toner container (not shown) detachably attached to the apparatus main body 100a. This collected toner container is replaced when it becomes full.

[0043] The cleaning scraper 185 is disposed so as to contact the surface of the intermediate transfer belt 101 downstream of the contact portion between the cleaning blade 181 and the surface of the intermediate transfer belt 101 in the moving direction V of the surface of the intermediate transfer belt 101. The cleaning scraper 185 is a sheet-like member having a predetermined length and a predetermined thickness in the longitudinal direction arranged along the width direction of the intermediate transfer belt 101 (substantially parallel in this embodiment) and in the short direction substantially perpendicular to the longitudinal direction, respectively, and having elasticity (flexibility). The cleaning scraper 185 may be a sheet-like member having a substantially rectangular shape in a plan view (FIG. 7, etc.), or may be a sheet-like member having a shape in which a part of the end in the longitudinal direction is cut out as described later (FIG. 8(a), etc.). The shape of the cleaning scraper 185 will be described later in more detail. At least a part of the tip 185a side of the cleaning scraper 185 in the short direction intersecting the longitudinal direction (substantially perpendicular in this embodiment) contacts the surface of the intermediate transfer belt 101. At least a part of the length of the base end 185b side in the short-side direction located downstream of the tip 185a in the surface movement direction V of the intermediate transfer belt 101 is fixed to the fixing part 186b of the second accommodating member 186. That is, the second accommodating member 186 has a fixing part 186b that extends in the long-side direction and fixes at least a part of the length of the base end 185b side in the short-side direction of the cleaning scraper 185. The cleaning scraper 185 is attached to the fixing part 186b of the second accommodating member 186 by, for example, double-sided tape. Note that the fixing method of the cleaning scraper 185 is not limited to the method using the double-sided tape. For example, the cleaning scraper 185 may be fixed by adhesion or welding with an adhesive, or may be fixed by using a fixing member made of a metal plate or a molded member (see Example 3). The cleaning scraper 185 is abutted against the surface of the intermediate transfer belt 101 so as to be in the counter direction with respect to the movement direction V of the surface of the intermediate transfer belt 101. That is, the cleaning scraper 185 is disposed so that a leading end 185a in the lateral direction is located upstream in the moving direction V of the surface of the intermediate transfer belt 101 relative to a base end 185b.As a result, the cleaning scraper 185 is disposed so that the tip 185a faces the upstream side in the moving direction V of the surface of the intermediate transfer belt 101. In this embodiment, the cleaning scraper 185 is formed of a polyester-based material, which is a resin material. In order to effectively collect the toner and paper dust that have slipped through the cleaning blade 181, it is preferable that the JIS-A hardness of the cleaning scraper 185 is about 80° or more and 100° or less. Similarly, in order to effectively collect the toner and paper dust that have slipped through the cleaning blade 181, it is preferable that the thickness of the cleaning scraper 185 is about 300 μm or more and 1 mm or less. In this embodiment, a polyester-based material is used as the material of the cleaning scraper 185, but the material is not limited to this. As the material of the cleaning scraper 185, a material having a higher hardness than the material of the cleaning blade 181 can be preferably used. The material of the cleaning scraper 185 may be, for example, a metal material such as SUS (stainless steel) or a resin material such as ABS (acrylonitrile-butadiene-styrene copolymer resin) or PET (polyethylene terephthalate).

[0044] When the cleaning blade 181 scrapes off the residual toner, the toner and paper dust that have slipped through the cleaning blade 181 are supplied to the cleaning scraper 185 by minute vibrations and gaps of the intermediate transfer belt 101 and the cleaning blade 181, and are collected by the cleaning scraper 185. The collected toner and paper dust are stored in a second storage section (paper dust storage section) 186a formed in the second storage member 186. The above-mentioned fixed section 186b is generally formed by the side surface of the second storage member 186 on the intermediate transfer belt 101 side in the region in which the second storage section 186a is formed inside in the longitudinal direction. The second storage section 186a is formed by the cleaning blade 181, the cleaning scraper 185, and a plurality of seal members (described later) that are arranged at both ends of the second storage member 186 in the longitudinal direction. In addition, the second storage member 186 is not provided with a function for discharging collected materials such as the toner and paper dust in the second storage section 186a. Therefore, the second container 186a has a space capable of accommodating toner, paper dust, and other materials that are collected within the replacement life of the intermediate transfer unit 200.

[0045] <Arrangement of sealing members in belt cleaning device> Next, there will be described the arrangement of the seal members in the belt cleaning device 180. The seal member on the rear side is shown in Fig. 6. As described above, the cleaning scraper 185 is not shown in Fig. 7.

[0046] As shown in FIG. 6 and FIG. 7, a shatterproof sheet 187 is provided along the longitudinal direction to prevent the collected materials from flowing back from an opening between the first storage member 184 and the intermediate transfer belt 101 wound around the steering roller 112 above the cleaning blade 181. The shatterproof sheet 187 is disposed above the cleaning blade 181, facing the cleaning blade 181 over the entire longitudinal area of ​​the cleaning blade 181. The shatterproof sheet 187 is a sheet-like member formed of a resin such as PET (polyethylene terephthalate). The shatterproof sheet 187 is in contact with the intermediate transfer belt 101 wound around the steering roller 112 with a predetermined contact pressure, with a free end (tip) in the lateral direction facing the downstream side in the moving direction of the surface of the intermediate transfer belt 101. A fixed end (base end) in the lateral direction of the shatterproof sheet 187 is fixed to the first storage member 184.

[0047] Further, scraper seals 189 are disposed at both ends of the second accommodating member 186 in the longitudinal direction to seal the gap between the cleaning scraper 185 and the second accommodating member 186 and the gap between the second accommodating member 186 and the intermediate transfer belt 101 wound around the steering roller 112. The scraper seal 189 is disposed on a surface (seat surface) of the second accommodating member 184 facing the intermediate transfer belt 101 so as to contact an end (end surface) 186c in the longitudinal direction of the second accommodating member 186 and protrude upward from an opening 186d of the second accommodating portion 186a. The scraper seal 189 is positioned on the opposite side of the cleaning scraper 185 to the intermediate transfer belt 101 and abuts against the cleaning scraper 185 (sandwiching the cleaning scraper 185 between the intermediate transfer belt 101 and the scraper seal 189).

[0048] Further, end seals 190 are arranged at both ends of the cleaning blade 181 in the longitudinal direction so as to seal the gap between the shatterproof sheet 187 and the first storage member 184, the gap between the first storage member 184 and the intermediate transfer belt 101 wound around the steering roller 112, and the gap between the second storage member 186 and the intermediate transfer belt 101 wound around the steering roller 112. The end seal 190 is arranged on the surface (seat surface) of the first storage member 184 facing the intermediate transfer belt 101 so as to contact the end (end surface) in the longitudinal direction of the cleaning blade 181. At the same time, the end seal 190 is arranged on the surface of the second storage member 186 facing the intermediate transfer belt 101 so as to contact the scraper sealing seal 189. Thus, in this embodiment, the end seal 190 is arranged across the first storage member 184 and the second storage member 186. In this embodiment, the end seal 190 is formed such that a portion of the scraper sealing seal 189 is sandwiched between a portion of the end seal 190 and the intermediate transfer belt 101. However, the end seal 190 may be formed so as to be cut out to match the contour of the scraper sealing seal 189 and to contact the end (end face) of the scraper sealing seal 189. As will be described in detail later, at least a portion of the end seal 190 is located on the opposite side of the cleaning scraper 185 from the intermediate transfer belt 101 and abuts against the cleaning scraper 185 (sandwiching the cleaning scraper 185 between the intermediate transfer belt 101 and the end seal 190).

[0049] In addition, in this embodiment, sealing seals 188 are arranged at both longitudinal ends of the cleaning blade 181 so as to seal the gap between the first accommodating member 184 and the cleaning blade 181, the gap between the second accommodating member 186 and the cleaning blade 181, and the gap between the second accommodating member 186 and the first accommodating member 184.

[0050] Each of the above-mentioned sealing members (seal 188, scraper seal 189, end seal 190) is formed of an elastic material, preferably a foamed elastic material such as urethane foam. In this embodiment, each of the above-mentioned sealing members (seal 188, scraper seal 189, end seal 190) is formed of urethane foam. However, the material of the sealing members is not limited to this, and other foamed elastic materials such as silicone sponge, or non-foamed rubber materials, etc. may also be used.

[0051] By disposing the seal member in this manner, the inside of the belt cleaning device 180 is sealed, and leakage of the collected materials to the outside of the belt cleaning device 180 is prevented.

[0052] <Positional relationship between cleaning scraper, fixed area and end seal> Next, a description will be given of the positional relationship between the cleaning scraper 185, the fixed area F, and the end seal 190. Fig. 8 is a schematic side view of the vicinity of the end of the cleaning scraper 185 in the longitudinal direction as viewed from the intermediate transfer belt 101 side, for explaining this positional relationship.

[0053] As described above, the belt cleaning device 180 is provided with the end seal 190 in order to prevent the collected material from leaking from the longitudinal end of the cleaning blade 181. In this case, in order to prevent the collected material from leaking from the longitudinal end of the cleaning scraper 185, it is desirable to arrange the end seal 190 so as to overlap the cleaning scraper 185 in the longitudinal direction, for example by arranging the end seal 190 so as to straddle the first accommodating member 184 and the second accommodating member 186 as described above.

[0054] However, in this case, the end seal 190 presses the cleaning scraper 185, which may increase the contact pressure between the intermediate transfer belt 101 and the cleaning scraper 185 at the longitudinal ends more than at the center. This may cause damage to the intermediate transfer belt 101, such as scratches on the surface of the intermediate transfer belt 101.

[0055] Furthermore, in the case where a steering mechanism is provided in the intermediate transfer unit 200 as in this embodiment, if the contact pressure at the end of the cleaning scraper 185 in the longitudinal direction increases as described above, this may cause a sliding resistance and hinder steering. This may be particularly noticeable when the steering mechanism is an autonomous steering mechanism as in this embodiment. Note that even in the case where a steering mechanism configured to tilt the steering roller by a driving means such as a motor is used, if the contact pressure at the end of the cleaning scraper 185 in the longitudinal direction increases as described above, this may cause steering to be hindered.

[0056] Therefore, in this embodiment, the cleaning scraper 185 is arranged outside the end of the fixed area F (fixed portion 186b) in the longitudinal direction, so that at least a portion of the tip 185a side in the lateral direction overlaps with at least a portion of the end seal 190 from the intermediate transfer belt 101 side.

[0057] That is, the cleaning scraper 185 is fixed to the fixing portion 186b of the second accommodating member 186 in the fixing region F. As described above, in this embodiment, the cleaning scraper 185 is fixed by placing double-sided tape on the fixing portion 186b in the fixing region F. Note that, as described above, the method of fixing the cleaning scraper 185 in the fixing region F is not limited to this.

[0058] Furthermore, since the cleaning scraper 185 is fixed in this fixed region F, when it comes into contact with the rotating intermediate transfer belt 101 to exert its cleaning effect, the position of the cleaning scraper 185 is not shifted by a reaction force from the intermediate transfer belt 101. In this embodiment, outside the end 186c of the fixed region F (fixed portion 186b) in the longitudinal direction, the fixed region F of the cleaning scraper 185 is not present in the region where the end seal 190 in the longitudinal direction is located.

[0059] Therefore, when the cleaning scraper 185 is pushed by the reaction force of the intermediate transfer belt 101 on the outside of the fixed region F in the longitudinal direction, the repulsive force of the cleaning scraper 185 itself is reduced. That is, on the outside of the fixed region F in the longitudinal direction, the end seal 190 receives the reaction force of the intermediate transfer belt 101 via the cleaning scraper 185. As a result, the end seal 190 pushes back the intermediate transfer belt 101 via the cleaning scraper 185 by the reaction force. However, in the fixed region F in the longitudinal direction, when the cleaning scraper 185 is pushed by the reaction force of the intermediate transfer belt 101, the cleaning scraper 185, which is substantially configured like a double-supported beam, pushes back the intermediate transfer belt 101 by its own repulsive force. Therefore, if the end seal 190 is installed in the fixed region F in the longitudinal direction, the following will happen. In other words, when the reaction force of the intermediate transfer belt 101 presses the cleaning scraper 185, the reaction force of the cleaning scraper 185 itself and the reaction force of the end seal 190 pressing the cleaning scraper 185 are transmitted to the intermediate transfer belt 101. As a result, the contact pressure between the intermediate transfer belt 101 and the cleaning scraper 185 at the longitudinal ends becomes higher than that at the longitudinal center.

[0060] Thus, in this embodiment, the positional relationship is as follows, from the inside in the longitudinal direction: the end of the fixed region F, the inner end 190a of the end seal 190, and the end 185c of the cleaning scraper 185. That is, in the longitudinal direction, the end 185c of the cleaning scraper 185 and the inner end 190a of the end seal 190 are outside the fixed region F. Also, in the longitudinal direction, outside the fixed region F, the inner end 190a of the end seal 190 is located inside the end 185c of the cleaning scraper 185. With such a positional relationship, it can be said that at least a portion of the cleaning scraper 185 overlaps with the end seal 190 outside the fixed region F in the longitudinal direction.

[0061] Here, as shown in FIG. 8, the cleaning scraper 185 may have a shape in which the width in the short side direction is approximately the same outside the fixed region F (fixed portion 186b) in the longitudinal direction as inside the fixed region F. In contrast, as shown in FIG. 9(a), the cleaning scraper 185 may have a shape in which the short side length W2 of at least a part of the region including the region overlapping with the end seal 190 outside the fixed region F (fixed portion 186b) in the longitudinal direction is shorter than the short side length W1 inside the fixed region F in the longitudinal direction. This makes it easier to suppress an increase in the contact pressure between the cleaning scraper 185 and the intermediate transfer belt 101 at the end in the longitudinal direction. Also, as shown in FIG. 9(a), the cleaning scraper 185 may have a shape in which the short side length of at least a part of the region including the region overlapping with the end seal 190 outside the fixed region F (fixed portion 186b) in the longitudinal direction is shorter toward the outside in the longitudinal direction. This makes it easier to prevent an increase in the contact pressure between the cleaning scraper 185 and the intermediate transfer belt 101 at the longitudinal end portions.

[0062] As shown in FIG. 8 and FIG. 9(a), the cleaning scraper 185 may have a longitudinal end 185c in an area overlapping with the end seal 190 in the lateral direction, located between the inner end 190a and the outer end 190b of the end seal 190 in the longitudinal direction. The end 185c of the cleaning scraper 185 may be located at the same position as the outer end 190b of the end seal 190. In contrast, as shown in FIG. 8(b), the cleaning scraper 185 may have a longitudinal end 185c in an area overlapping with the end seal 190 in the lateral direction, located outside the outer end 190b of the end seal 190 in the longitudinal direction. This makes it easier to prevent collected materials from leaking from the longitudinal end of the cleaning scraper 185 (see Example 3).

[0063] In this manner, the configuration of this embodiment can prevent the collected material from leaking from the longitudinal ends of the cleaning scraper 185, while also preventing an increase in the contact pressure between the cleaning scraper 185 and the intermediate transfer belt 101 at those ends.

[0064] <Relationship with edge toner slippage> Next, the mechanism by which end toner slip-through occurs will be described as an example of a situation in which it is preferable to overlap the cleaning scraper 185 with the end seal 190 in the longitudinal direction. Fig. 10 is a schematic diagram showing the relationship between the longitudinal lengths of each part and the distribution of frictional force between the intermediate transfer belt 101 and the cleaning blade 181 in the longitudinal direction, in order to explain the mechanism by which end toner slip-through occurs. Fig. 11 is a schematic diagram similar to Fig. 10, further adding the distribution of the surface height of the cleaning blade in the longitudinal direction.

[0065] In FIG. 10, toner and external additives are supplied to a toner image forming area on intermediate transfer belt 101 (area where a toner image can be formed (image forming area) (represented as toner image in FIG. 10)). Even outside the toner image forming area, minute fog toner is supplied onto intermediate transfer belt 101 at a position corresponding to an area where toner is coated on a developing member (developer carrier) that supplies toner to photosensitive drum 103 provided in developing device 106. As a result, the coefficient of friction μ between cleaning blade 181 and intermediate transfer belt 101 in this area becomes small.

[0066] On the other hand, in an area on the intermediate transfer belt 101 where toner or external additives are not supplied (an area outside the area where the developing member of the developing device 106 is coated with toner), the friction coefficient μ becomes large. Hereinafter, this area will be referred to as a "high μ area." Note that, from the viewpoint of cleaning the surface of the intermediate transfer belt 101 better, the cleaning blade 181 is often brought into contact with the intermediate transfer belt 101 even in this high μ area. As a result, the frictional force between the intermediate transfer belt 101 and the cleaning blade 181 has a profile as shown in FIG. 10. In FIG. 10, if the frictional force between the intermediate transfer belt 101 and the cleaning blade 181 becomes large beyond the dashed line a, problems such as the cleaning blade 181 turning over may occur.

[0067] 11, a hardening treatment is sometimes performed on the surface of the urethane rubber of the cleaning blade 181 that contacts the intermediate transfer belt 101 in the high μ region to provide a hardening treatment portion 181a. This hardens the surface of the urethane rubber, thereby lowering the friction coefficient μ in the high μ region and reducing the frictional force between the intermediate transfer belt 101 and the cleaning blade 181 to less than the dashed line a, thereby preventing the cleaning blade 181 from curling up. The hardening treatment can be performed by a known method of impregnating the urethane rubber that constitutes the cleaning blade 181 with an isocyanate compound (JP Patent Publication 2009-42581 A).

[0068] However, a step of 70 to 160 μm occurs at the boundary between the hardening treatment portion 181a and the non-hardening treatment area. The gap between the intermediate transfer belt 101 and the cleaning blade 181, which occurs at the step, may cause toner to easily slip through. For example, the high μ area is located in an area 10 mm from both ends of the cleaning blade 181 in the longitudinal direction, and in this case, the hardening treatment is also performed in approximately the same area as the high μ area. As described above, the toner that has slipped through the cleaning blade 181 is collected by the cleaning scraper 185 and stored in the second storage portion 186a.

[0069] The state of the second storage member 186 when the toner is likely to slip through due to the step between the hardened areas 181a at both ends of the cleaning blade 181 in the longitudinal direction and the non-hardened areas as described above will be described. Fig. 12 is a side view seen from the intermediate transfer belt 101 side showing the configuration near the end of the belt cleaning device 180, Fig. 12(a) shows an example of a configuration in which the cleaning scraper 185 does not overlap the end seal 190 in the longitudinal direction, and Fig. 12(b) shows an example of a configuration in which they do overlap. In Figs. 12(a) and 12(b), elements having the same or corresponding functions or configurations are given the same reference numerals.

[0070] As shown in FIG. 12(a), toner T that has slipped through the cleaning blade 181 and is collected by the cleaning scraper 185 accumulates at both ends of the second storage section 186a in the longitudinal direction. The toner T that has slipped through the cleaning blade 181 accumulates at an angle of repose θ with the falling position as the apex. Therefore, if the scraper sealing seal 189 is disposed inside the longitudinal end 181c of the cleaning blade 181, the toner T reaches the scraper sealing seal 189 early. Then, the toner T may leak out from a minute gap that occurs in the scraper sealing seal 189.

[0071] 12(b), the end 185c in the longitudinal direction of the cleaning scraper 185 and the scraper sealing seal 189 are disposed outside the end 181c in the longitudinal direction of the cleaning blade 181. This ensures a distance from the position where the toner T falls due to the step of the hardening processing portion 181a of the cleaning blade 181 to the scraper sealing seal 189 (the end 186c of the second storage member 186) in the longitudinal direction of the cleaning blade 181. As a result, it is possible to increase the amount of toner stored in the second storage portion 186a in the second storage member 186, which accumulates due to the end toner slipping through the step of the hardening processing portion 181a, and to suppress leakage of the toner T.

[0072] 12(b), in order to prevent collected materials from leaking from the longitudinal ends of the cleaning scraper 185, it is desirable to overlap the cleaning scraper 185 with the end seal 190. In this case, as described above, by overlapping the cleaning scraper 185 with the end seal 190 outside the longitudinal fixing region F (fixing portion 186b), it is possible to prevent an increase in the contact pressure between the cleaning scraper 185 and the intermediate transfer belt 101 at the longitudinal ends.

[0073] <Positional relationship between the cleaning scraper and the edge of the intermediate transfer belt> Next, an example of a preferable positional relationship between the cleaning scraper 185 and the end of the intermediate transfer belt 101 when the length of the cleaning scraper 185 in the longitudinal direction is extended will be described.

[0074] FIG. 13(a) is a schematic side view for explaining an example of the positional relationship between the cleaning scraper 185 and the end of the intermediate transfer belt 101. FIG. 13(b) is a schematic cross-sectional view of the vicinity of the end of the intermediate transfer belt 101 in the width direction in the configuration of FIG. 13(a) (showing a cross section along the width direction of the intermediate transfer belt 101). FIG. 14(a) and (b) are schematic side views for explaining a preferred example of the positional relationship between the cleaning scraper 185 and the end of the intermediate transfer belt 101. FIG. 14(a) shows a state in which the conveying position in the width direction of the intermediate transfer belt 101 is at the nominal center position, and FIG. 14(b) shows a state in which the conveying position in the width direction of the intermediate transfer belt 101 is shifted to the right in the figure. FIG. 14(c) is a schematic cross-sectional view of the vicinity of the end of the intermediate transfer belt 101 in the width direction in the state of FIG. 14(b) (showing a cross section along the width direction of the intermediate transfer belt 101).

[0075] First, as shown in FIGS. 13(a) and 13(b), a case will be described in which the end 185c in the longitudinal direction of the cleaning scraper 185 is disposed inside the end in the width direction of the intermediate transfer belt 101. The material of the cleaning scraper 185 is preferably harder than the material of the cleaning blade 181. Therefore, the end edge 185E of the cleaning scraper 185 has a higher sliding resistance against the intermediate transfer belt 101 than the end edge 181E of the cleaning blade 181. This may hinder the correction (steering) of the deviation of the intermediate transfer belt 101 by the autonomous steering mechanism 210. If the autonomous steering mechanism 210 does not function and the intermediate transfer belt 101 is completely shifted, the intermediate transfer belt 101 may be damaged.

[0076] Therefore, as shown in FIG. 14(a), the longitudinal end 185c of the cleaning scraper 185 is extended outward along the longitudinal direction. In the state of FIG. 14(a), the longitudinal end 185c of the cleaning scraper 185 is positioned on the sliding ring portion 212. Even in this state, the influence of the end edge 185E of the cleaning scraper 185 on steering can be suppressed. Here, it is desirable that the amount of extension of the longitudinal length of the cleaning scraper 185 be as small as possible from the viewpoint of space saving and the like.

[0077] Therefore, as shown in FIG. 14(b), it is preferable to arrange the end 185c of the cleaning scraper 185 in the longitudinal direction as follows. That is, the end 185c is arranged so as to be located outside the end (edge) 76a of the reinforcing tape 76 on the center side in the width direction of the intermediate transfer belt 101 even when the intermediate transfer belt 101 is shifted toward the end 185c side (the right direction in FIG. 13(b)). Preferably, the end 185c is arranged so as to be located between the end (edge) 76a of the reinforcing tape 76 on the center side in the width direction of the intermediate transfer belt 101 and the outer end (edge) 76b side even when the intermediate transfer belt 101 is shifted toward the above direction. As a result, the end edge 185E of the cleaning scraper 185 does not come into contact with the surface of the intermediate transfer belt 101 (the surface of the surface layer 75, i.e., the surface of the intermediate transfer belt 101 that forms the same plane as the toner image forming area at the center in the width direction). In addition, as shown in FIG. 14(c), when the intermediate transfer belt 101 is fully shifted in the above direction, the end edge 185E of the cleaning scraper 185 is disposed on the intermediate transfer belt 101 (on the reinforcing tape 76) in the width direction of the intermediate transfer belt 101. However, since the vicinity of the end 185c of the cleaning scraper 185 rides up on the reinforcing tape 76, the end edge 185E often does not come into contact with the reinforcing tape 76. Even if it does come into contact, the contact pressure is reduced because the vicinity of the end 185c of the cleaning scraper 185 rides up on the reinforcing tape 76 as described above. As a result, the sliding resistance is reduced, and it is possible to suppress the autonomous steering mechanism 210 from impeding the correction (steering) of the shift of the intermediate transfer belt 101.

[0078] Although the above description is given for one end of the intermediate transfer belt 101 in the width direction, the other end of the intermediate transfer belt 101 may also be arranged in a similar manner to the above when the intermediate transfer belt 101 shifts in the opposite direction to the above.

[0079] <Effects> Thus, in this embodiment, the belt conveying device (intermediate transfer unit) 200 includes an endless belt 101 that is stretched around a plurality of tension rollers and that carries a toner image on its surface and is capable of circulating, and a cleaning device 180 that extends in a longitudinal direction along a width direction that is approximately perpendicular to the direction of movement of the surface of the belt 101 and cleans the surface of the belt 101. The cleaning device 180 includes a blade-shaped first cleaning member 181 that extends in the longitudinal direction and comes into contact with the surface of the belt 101, and a blade-shaped second cleaning member 182 that extends in the longitudinal direction and comes into contact with the surface of the belt 101. The cleaning device includes a sheet-like second cleaning member 185 that contacts the surface of the belt 101 downstream of the contact point between the first cleaning member 181 and the surface of the belt 101 in the movement direction, end seals 190 that are provided on both end sides of the first cleaning member 181 in the longitudinal direction and arranged to contact the ends of the first cleaning member 181 and the surface of the belt 101, and a container 180a that holds the first cleaning member 181, the second cleaning member 185, and the end seals 190. In this embodiment, at least a portion of the tip side of the second cleaning member 185 in the short direction intersecting the longitudinal direction abuts against the surface of the belt 101, and at least a portion of the base end side in the long direction located downstream of the tip side in the moving direction is fixed to the container 180a, the container 180a has a fixing portion 186b extending in the long direction and fixing at least a portion of the base end side in the long direction of the second cleaning member 185 in the short direction, and the second cleaning member 185 is arranged so that at least a portion of the tip side in the short direction overlaps with at least a portion of the end seal 190 from the belt side, outside the end of the fixing portion 186b in the long direction, on each of both end sides in the long direction. The second cleaning member 185 can be configured such that, at each of both end sides in the longitudinal direction, the longitudinal end in the area overlapping with the short-side end seal 190 is positioned outer than the outer end of the end seal 190 in the longitudinal direction.The second cleaning member 185 may be configured such that, at both ends in the longitudinal direction, the length in the lateral direction of at least a portion of the region including the region overlapping with the end seal 190 outside the end of the fixed portion 186b in the longitudinal direction is shorter than the length in the lateral direction of the region inside the end of the fixed portion 186b in the longitudinal direction. The second cleaning member 185 may be configured such that, at both ends in the longitudinal direction, the length in the lateral direction of at least a portion of the region including the region overlapping with the end seal 190 outside the end of the fixed portion 186b in the longitudinal direction is shorter toward the outside in the longitudinal direction. It is also preferable that the edges of both ends in the longitudinal direction of the second cleaning member 185 do not come into contact with the surface of the belt 101. In this embodiment, the belt conveying device 200 has a steering mechanism 210 that tilts a first tension roller (steering roller) 112 of the multiple tension rollers relative to a second tension roller (driving roller) 110 of the multiple tension rollers to change the conveying position of the belt 101 in the axial direction of the first tension roller 112. Regardless of the conveying position of the belt 101 in the axial direction of the first tension roller 112, it is preferable that the edges of both ends of the second cleaning member 185 in the longitudinal direction do not contact the surface of the belt 101. For example, at both ends of the belt 101 in the width direction, a reinforcing member 76 extending along the circumferential direction of the belt 101 may be provided on the surface of the belt 101. In this case, regardless of the conveying position of the belt 101 in the axial direction of the first tension roller 112, the edges of both ends of the second cleaning member 185 in the longitudinal direction can be positioned outside the edges of the reinforcing member 76 at the ends on the center side in the width direction of the belt 101.

[0080] As described above, according to this embodiment, it is possible to prevent the contact pressure between the intermediate transfer belt 101 and the cleaning scraper 185 from being higher at the ends than at the center in the longitudinal direction, while preventing leakage of toner T from the belt cleaning device 180.

[0081] Furthermore, when the length of the cleaning scraper 185 in the longitudinal direction is extended, the arrangement of the longitudinal end of the cleaning scraper 185 as shown in Fig. 14 can suppress damage to the intermediate transfer belt 101 compared to the arrangement shown in Fig. 13. This makes it possible to provide a highly durable intermediate transfer unit 200.

[0082] In this embodiment, the endless belt that carries the toner image is an intermediate transfer belt, but it may be a photosensitive belt, an electrostatic recording dielectric belt, etc. The same applies to other embodiments described later.

[0083] [Example 2] Next, another embodiment of the present invention will be described. The basic configuration of the image forming apparatus of this embodiment is the same as that of the image forming apparatus of embodiment 1. Therefore, in the image forming apparatus of this embodiment, elements having the same or corresponding functions or configurations as those of the image forming apparatus of embodiment 1 are given the same reference numerals as those of embodiment 1, and detailed explanations are omitted.

[0084] In the first embodiment, an example of a preferable positional relationship between the cleaning scraper 185 and the end of the intermediate transfer belt 101 in the case where the reinforcing tape 76 is provided on the intermediate transfer belt 101 has been described.

[0085] In this embodiment, a case will be described in which the reinforcing tape 76 is not provided on the ends of the intermediate transfer belt 101 in the width direction because the intermediate transfer belt 101 itself has sufficient strength.

[0086] 15(a) and (b) are schematic side views for explaining a preferred example of the positional relationship between the cleaning scraper 185 and the end of the intermediate transfer belt 101. Fig. 15(a) shows a state in which the conveying position in the width direction of the intermediate transfer belt 101 is at the nominal center position, and Fig. 15(b) shows a state in which the conveying position in the width direction of the intermediate transfer belt 101 is shifted far to the right in the figure. Fig. 15(c) is a schematic cross-sectional view of the vicinity of the end in the width direction of the intermediate transfer belt 101 in the state of Fig. 15(b) (showing a cross-section along the width direction of the intermediate transfer belt 101).

[0087] As described with reference to FIG. 14(a) in the first embodiment, the longitudinal end of the cleaning scraper 185 is extended outward along the longitudinal direction as shown in FIG. 15(a). In the state of FIG. 15(a), the longitudinal end 185c of the cleaning scraper 185 is positioned on the sliding ring portion 212. Even in this state, the influence of the end edge 185E of the cleaning scraper 185 on steering can be suppressed. Here, as described in the first embodiment, it is desirable that the extension amount of the longitudinal length of the cleaning scraper 185 is as small as possible from the viewpoint of space saving and the like.

[0088] Therefore, as shown in FIG. 15(b), it is preferable to arrange the end 185c of the cleaning scraper 185 in the longitudinal direction as follows. That is, the end 185c is arranged so as to be located outside the end edge 101E in the width direction of the intermediate transfer belt 101 even when the intermediate transfer belt 101 is shifted toward the end 185c side (the right direction in FIG. 14(b)). As a result, as shown in FIG. 15(c), the end edge 185E of the cleaning scraper 185 does not contact the surface of the intermediate transfer belt 101 (the surface of the surface layer 75, i.e., the surface of the intermediate transfer belt 101 that forms the same plane as the toner image forming area at the center in the width direction). As a result, it is possible to suppress the autonomous steering mechanism 210 from hindering the correction (steering) of the shift of the intermediate transfer belt 101.

[0089] Although the above description is given for one end of the intermediate transfer belt 101 in the width direction, the other end of the intermediate transfer belt 101 may also be arranged in a similar manner to the above when the intermediate transfer belt 101 shifts in the opposite direction to the above.

[0090] In this way, regardless of the conveying position of the belt 101 in the axial direction of the first tension roller (steering roller) 112, it is preferable that the edges of both ends in the longitudinal direction of the second cleaning member 185 are positioned outside the edges of the ends of the belt 101 in the width direction.

[0091] As described above, according to this embodiment, even in a configuration using an intermediate transfer belt 101 that is not provided with a reinforcing tape 76, it is possible to suppress damage to the intermediate transfer belt 101 when the length of the cleaning scraper 185 in the longitudinal direction is extended. This makes it possible to provide a highly durable intermediate transfer unit 200.

[0092] [Example 3] Next, another embodiment of the present invention will be described. The basic configuration of the image forming apparatus of this embodiment is the same as that of the image forming apparatus of embodiment 1. Therefore, in the image forming apparatus of this embodiment, elements having the same or corresponding functions or configurations as those of the image forming apparatus of embodiment 1 are given the same reference numerals as those of embodiment 1, and detailed explanations are omitted.

[0093] In this embodiment, a configuration in which a cleaning scraper 185 is fixed using a scraper fixing metal plate 191 (FIG. 16) as a fixing member will be described.

[0094] <Effect of scraper fixing sheet metal> Fig. 16 is a side view showing the configuration of the vicinity of the end of the belt cleaning device 180 in this embodiment as seen from the intermediate transfer belt 101 side. Figs. 17 and 18 are perspective views showing the vicinity of the end of the second accommodating member 186 of the belt cleaning device 180 in this embodiment, with Fig. 17 showing the state as seen from the side facing the fixed portion 186b and Fig. 18 showing the state as seen from the side facing the opening 168d of the second accommodating portion 168a.

[0095] As shown in FIG. 16, in this embodiment, the fixing portion 186b of the second housing member 186 and the scraper fixing metal plate 191 as a fixing member are fixed, and the cleaning scraper 185 is installed at a position sandwiched between the fixing portion 186b and the scraper fixing metal plate 191. In this embodiment, the scraper fixing metal plate 191 is fixed to the second housing member 186 by passing a screw 300 through a through hole (not shown) provided in the scraper fixing metal plate 191 and the cleaning scraper 185 and screwing it into a screw hole 186g provided in the fixing portion 186b of the second housing member 186. Thus, in this embodiment, the scraper fixing metal plate 191 is arranged so as to sandwich the cleaning scraper 185 between the fixing portion 186b of the second housing member 186. For example, fixing by the scraper fixing metal plate 191 and the double-sided tape may be used in combination.

[0096] This configuration is effective when the contact pressure between the cleaning scraper 185 and the intermediate transfer belt 101 is increased in order to enhance the cleaning effect of the cleaning scraper 185. By increasing the contact pressure between the cleaning scraper 185 and the intermediate transfer belt 101, the cleaning effect of the cleaning scraper 185 is enhanced. On the other hand, in this case, the reaction force to the cleaning scraper 185 increases, so that the position of the cleaning scraper 185 is more likely to be shifted. For example, when the cleaning scraper 185 is fixed only with the double-sided tape installed in the fixing area F, the force for fixing the cleaning scraper 185 is smaller than when the scraper fixing plate 191 is used as in this embodiment. Therefore, when the contact pressure between the cleaning scraper 185 and the intermediate transfer belt 101 is increased, the double-sided tape may peel off and the position of the cleaning scraper 185 may be shifted.

[0097] 17, in this embodiment, the scraper sealing seal 189 is disposed on a surface (seat surface) 186f of the second accommodating member 184 facing the intermediate transfer belt 101 so as to contact an end (end face) 186c in the longitudinal direction of the second accommodating member 186 and protrude upward beyond the opening 186d of the second accommodating portion 186a. The scraper sealing seal 189 is located on the opposite side of the cleaning scraper 185 to the intermediate transfer belt 101 and abuts against the cleaning scraper 185 (sandwiching the cleaning scraper 185 between the cleaning scraper 185 and the intermediate transfer belt 101).

[0098] Also, as shown in FIG. 17, in this embodiment, the end seal 190 is disposed on a surface 184b of the first accommodating member 184 facing the intermediate transfer belt 101 so as to contact the longitudinal end (end surface) of the cleaning blade 181. At the same time, the end seal 190 is disposed on a surface 186f of the second accommodating member 186 facing the intermediate transfer belt 101 so as to contact the scraper sealing seal 189. In this manner, the end seal 190 is disposed across the first accommodating member 184 and the second accommodating member 186. In this embodiment, the end seal 190 is formed so that a part of the scraper sealing seal 189 is sandwiched between a part of the end seal 190 and the intermediate transfer belt 101. Also, at least a part of the end seal 190 is located on the opposite side of the cleaning scraper 185 from the intermediate transfer belt 101 and abuts against the cleaning scraper 185 (sandwiching the cleaning scraper 185 between the intermediate transfer belt 101).

[0099] To explain further, the scraper fixing metal plate 191 is a plate-like member having a predetermined length in the longitudinal direction arranged along the width direction of the intermediate transfer belt 101 (substantially parallel in this embodiment) and in the lateral direction substantially perpendicular to the longitudinal direction, and having a predetermined thickness. In this embodiment, the scraper fixing metal plate 191 is formed of a metal material such as SUS (stainless steel). However, the fixing member may be formed of a molded member made of a resin material. In this embodiment, the scraper fixing metal plate 191 is a plate-like member having a substantially rectangular shape in a plan view. The tip (upper) of the scraper fixing metal plate 191 in the lateral direction is located above the upper end of the fixing portion 186b of the second housing member 186. In addition, the base end (lower) of the scraper fixing metal plate 191 in the lateral direction is located at substantially the same position as the lower end of the fixing portion 186b of the second housing member 186. In this embodiment, the end 191c of the scraper fixing sheet metal 191 in the longitudinal direction is located outside the fixing region F (fixing portion 186b). As a result, in this embodiment, the scraper fixing sheet metal 191 sandwiches the scraper sealing seal 189 between itself and the seat surface 186f.

[0100] In this embodiment, the end 186c of the fixed region F (fixed portion 186b) is located inside the end 181c of the cleaning blade 181 in the longitudinal direction. Also in this embodiment, as in the first embodiment, the cleaning scraper 185 is provided outside the end of the fixed region F (fixed portion 186b) in the longitudinal direction, such that at least a part of the tip 185a side in the lateral direction overlaps with at least a part of the end seal 190 from the intermediate transfer belt 101 side. In particular, in this embodiment, the cleaning scraper 185 has a longitudinal end 185c in an area overlapping with the lateral end seal 190, which is located outside the outer end 190b of the end seal 190 in the longitudinal direction. This makes it easier to prevent collected materials from leaking from the longitudinal end of the cleaning scraper 185, as described later.

[0101] In this embodiment, the cleaning scraper 185 is provided outside the end 191c of the scraper fixing metal plate 191 in the longitudinal direction, such that at least a part of the tip 185a side in the lateral direction overlaps with at least a part of the end seal 90 from the intermediate transfer belt 101 side. This makes it possible to suppress an increase in the contact pressure between the cleaning scraper 185 and the intermediate transfer belt 101 by the end seal 190 in the region where the scraper fixing metal plate 191 is provided in the longitudinal direction.

[0102] Thus, in this embodiment, the second cleaning member 185 is disposed so as to sandwich the fixed member 191 between itself and the fixed portion 186b, and the second cleaning member 185 is disposed on each of both end sides in the longitudinal direction, outside the end of the fixed member 191 in the longitudinal direction, such that at least a portion of the tip side in the lateral direction overlaps with at least a portion of the end seal 190 from the belt side.

[0103] 18, in this embodiment, in the longitudinal direction, an end (end surface) 186c of the fixing portion 186b of the second accommodating member 186 is positioned outward from an end (inner surface) 186h of the second accommodating portion 186a by the width W3. Also, in a direction intersecting (approximately perpendicular in this embodiment) the longitudinal direction when the opening 186d of the second accommodating portion 186a is viewed from above, that is, in the thickness direction of the cleaning scraper 185, the seat surface 186f is provided at a position farther from the cleaning scraper 185 than the fixing portion 186b. As a result, in a direction intersecting (approximately perpendicular in this embodiment) the longitudinal direction when the opening 186d of the second storage portion 186a is viewed from above, i.e., in the thickness direction of the cleaning scraper 185, the inner surface 186i on the fixed portion 186b side (cleaning scraper 185 side) of the second storage portion 186a can protrude outward (toward the cleaning scraper 185) by the width W4 beyond the seat surface 186f on which the scraper sealing seal 189 is disposed. As a result, in this embodiment, the volume of the second storage portion 186a is increased.

[0104] In this manner, the belt conveying device 200 may have first end seals 190 provided at both longitudinal end sides of the first cleaning member (cleaning blade) 181 and arranged to abut against the end of the first cleaning member 181 and the surface of the belt 101, and second end seals 189 provided at both longitudinal end sides of the second cleaning member (cleaning scraper) 185 and arranged to abut against the end of the second cleaning member 185 and the first end seals 190. In this embodiment, container (cleaning container) 180a is provided with a seat 186f for fixing the second end seal 189, and a storage section (second storage section) 186a for storing the collected material collected by the second cleaning member 185, and in the thickness direction of the second cleaning member 185 which is perpendicular to the longitudinal direction of the second cleaning member 185, the seat 186f is provided at a position farther from the second cleaning member 185 than the fixed section 186b, and in the thickness direction, an inner surface 186i provided on the fixed section side of the storage section 186a is provided so as to protrude outward more than the seat 186f.

[0105] <Longitudinal position of scraper fixing sheet metal and scraper sealing seal> As shown in FIG. 16, in this embodiment, the end 191c of the scraper fixing metal plate 191 is located inside both ends 190a, 190b of the end seal 190 and outside the end 181 of the cleaning blade 181 in the longitudinal direction. From the viewpoint of reducing the contact pressure between the intermediate transfer belt 101 and the cleaning scraper 185, it is desirable that the scraper sealing seal 189 and the end seal 190 are not located in a position overlapping with the scraper fixing metal plate 191 in the entire area in the longitudinal direction. Therefore, for example, if the scraper sealing seal 189 is installed further inward, the area where the scraper sealing seal 189 and the end seal 190 overlap outside the fixing area F and the contact pressure becomes high as described above can be minimized. However, in such a configuration, the end 186c of the second storage section 186a is located further inward, and the amount of collected materials such as toner and paper powder that can be stored in the second storage section 186a is reduced, and the collected materials are more likely to leak or slip through. That is, in order to ensure a certain volume of the second accommodating member 186, it is desirable to dispose the end portion 186c of the second accommodating member 186 on the outside in the longitudinal direction and to extend the second accommodating portion 186a in the longitudinal direction. As a result, a part of the scraper sealing seal 189 overlaps with the end seal 190 in the longitudinal direction.

[0106] In addition, in this embodiment, since the scraper fixing metal plate 191 is fixed to the second accommodating member 186 with screws, the position of the screws needs to be a certain distance inward from the end portion 186c of the second accommodating member 186.

[0107] For the two reasons described above, the scraper fixing sheet metal 191 is positioned so as to partially overlap the end seal 190 and the scraper sealing seal 189 in the longitudinal direction. From the viewpoint of reducing the area where the contact pressure is high as described above, it is desirable to arrange the end 191c of the scraper fixing sheet metal 191 in the longitudinal direction as far inside as possible while satisfying requirements regarding the volume of the second housing member 186.

[0108] <Cleaning scraper end shape> 16, in this embodiment, a part of the outer side of the fixing area F of the cleaning scraper 185 is shaped so that the length in the short direction becomes shorter as it goes outward from the fixing area F. By extending the upper end 185c (the tip 185a side) of the cleaning scraper 185 outward, it is possible to lengthen the path from the end of the second storage section 186a to the leakage of collected materials such as toner and paper powder.

[0109] 19(a) and (b) are side views seen from the intermediate transfer belt 101 side, showing the configuration near the end of the belt cleaning device 180, for explaining the effect of the shape of the cleaning scraper 185 in this embodiment as described above.

[0110] 19(b) shows a state in which the second storage section 186a is filled with toner T and toner T leaks out when the upper end 185c of the cleaning scraper 185 is not extended outward. When the second storage section 186a is filled with toner T, the toner T advances outward along the upper end (tip 185a) of the cleaning scraper 185. Then, since the upper end 185c of the cleaning scraper 185 is not extended outward, the toner T falls directly from the end 185c of the cleaning scraper 185.

[0111] In contrast, FIG. 19(a) shows a state in which the toner T is fully accumulated in the second storage section 186a and leaks out when the upper end 185c of the cleaning scraper 185 is extended outward as in this embodiment. Compared to the case of FIG. 19(b), the distance until the toner T leaks is longer by the amount of the upper end 185c of the cleaning scraper 185 extended outward, and the toner T is less likely to leak outward. However, as described in the first embodiment, from the viewpoint of space saving, it is desirable that this extension amount be as short as possible. Therefore, it is desirable to set the extension amount to an optimal length that can achieve both securing the distance until the toner leaks and space saving. [Explanation of symbols]

[0112] 100 Image forming device 106 Developing device 200 Intermediate transfer unit 101 Intermediate transfer belt 180 Belt cleaning device 181 Cleaning blade 184 First storage member 184a First Storage Unit 185 Cleaning Scraper 186 Second storage member 186a Second Storage Unit 189 Scraper Seal 190 End seal

Claims

1. an endless belt that is stretched around a plurality of tension rollers and carries a toner image on its surface; a cleaning device extending in a longitudinal direction along a width direction substantially perpendicular to a moving direction of the surface of the belt and configured to clean the surface of the belt; having The cleaning device includes: a blade-shaped first cleaning member extending in the longitudinal direction and contacting the surface of the belt; a sheet-like second cleaning member extending in the longitudinal direction and contacting the surface of the belt downstream of a contact portion between the first cleaning member and the surface of the belt in the moving direction; end seals provided on both end sides of the first cleaning member in the longitudinal direction and arranged to abut against the ends of the first cleaning member and the surface of the belt; a container for holding the first cleaning member, the second cleaning member, and the end seal; In a belt conveying device having At least a part of a tip end side of the second cleaning member in a short side direction intersecting with the longitudinal direction is in contact with the surface of the belt, and at least a part of a base end side of the second cleaning member in the long side direction located downstream of the tip end in the moving direction is fixed to the container, the container has a fixing portion extending in the longitudinal direction and fixing at least a part of the second cleaning member in the longitudinal direction on a base end side in the lateral direction, the second cleaning member is arranged on each of both end sides in the longitudinal direction, outside the end of the fixed portion in the longitudinal direction, such that at least a portion of the tip side in the short direction overlaps with at least a portion of the end seal from the belt side.

2. 2. The belt conveying device according to claim 1, wherein the second cleaning member has an end portion on each of both ends in the longitudinal direction, the end portion in the longitudinal direction in the area overlapping with the end seal in the short direction being positioned outside the outer end portion of the end seal in the longitudinal direction.

3. 2. The belt conveying device according to claim 1, wherein the second cleaning member has a widthwise length of at least a portion of an area, including an area overlapping with the end seal, that is outer than the end of the fixed portion in the longitudinal direction, which is shorter than the widthwise length of an area inner than the end of the fixed portion in the longitudinal direction, at each of both end sides in the longitudinal direction.

4. 2. The belt conveying device according to claim 1, wherein the second cleaning member has a widthwise length, at least a portion of which, at each of both end sides in the longitudinal direction, is shorter toward the outside in the longitudinal direction than the end of the fixed portion, the widthwise length of at least a portion of which, including the area overlapping with the end seal, is shorter toward the outside in the longitudinal direction.

5. a fixed member extending in the longitudinal direction and disposed so as to sandwich the second cleaning member between the fixed portion and the fixed member, 2. The belt conveying device according to claim 1, wherein the second cleaning member is arranged on each of both end sides in the longitudinal direction, outside the end of the fixed member in the longitudinal direction, such that at least a portion of the tip side in the short direction overlaps with at least a portion of the end seal from the belt side.

6. 2. The belt conveying device according to claim 1, wherein the edges of the second cleaning member at both ends in the longitudinal direction do not contact the surface of the belt.

7. 2. The belt conveying device according to claim 1, further comprising a steering mechanism that tilts a first tension roller among the plurality of tension rollers relative to a second tension roller among the plurality of tension rollers to change the conveying position of the belt in the axial direction of the first tension roller.

8. 8. The belt transport device according to claim 7, wherein the edges of both ends of the second cleaning member in the longitudinal direction do not contact the surface of the belt, regardless of the belt transport position in the axial direction of the first tension roller.

9. A reinforcing member is provided on a surface of the belt at each of both ends in a width direction of the belt, the reinforcing member extending along a circumferential direction of the belt, The belt conveying device according to claim 7, characterized in that, regardless of the belt conveying position in the axial direction of the first tension roller, the edges of both ends of the second cleaning member in the longitudinal direction are each located outside the edges of the ends of the reinforcing member on the central side in the width direction of the belt.

10. 8. The belt conveying device according to claim 7, wherein the edges of both ends of the second cleaning member in the longitudinal direction are positioned outside the edges of the ends of the belt in the width direction, regardless of the belt conveying position in the axial direction of the first tension roller.

11. the end seal is a first end seal; a second end seal is provided on each of both end sides of the second cleaning member in the longitudinal direction and arranged to abut against an end of the second cleaning member and the first end seal; the container includes a seat to which the second end seal is fixed, and a storage portion for storing a collected matter collected by the second cleaning member, 2. The belt conveying device according to claim 1, wherein in a thickness direction of the second cleaning member perpendicular to the longitudinal direction of the second cleaning member, the seating surface is provided at a position farther from the second cleaning member than the fixed portion, and an inner surface of the accommodating portion on the fixed portion side in the thickness direction is provided so as to protrude outward beyond the seating surface.

12. an endless belt that is stretched around a plurality of tension rollers and carries a toner image on its surface; a cleaning device extending in a longitudinal direction along a width direction substantially perpendicular to a moving direction of the surface of the belt and configured to clean the surface of the belt; having The cleaning device includes: a blade-shaped first cleaning member extending in the longitudinal direction and contacting the surface of the belt; a sheet-like second cleaning member extending in the longitudinal direction and contacting the surface of the belt downstream of a contact portion between the first cleaning member and the surface of the belt in the moving direction; In a belt conveying device having a second cleaning member having a first edge and a second edge which are arranged on both ends of the second cleaning member in the longitudinal direction of the belt and which do not contact the surface of the belt;

13. 13. The belt conveying device according to claim 12, further comprising a steering mechanism that tilts a first tension roller among the plurality of tension rollers relative to a second tension roller among the plurality of tension rollers to change the conveying position of the belt in the axial direction of the first tension roller.

14. an endless belt that is stretched around a plurality of tension rollers and carries a toner image on its surface; a cleaning device extending in a longitudinal direction along a width direction substantially perpendicular to a moving direction of the surface of the belt and configured to clean the surface of the belt; a steering mechanism that tilts a first tension roller among the plurality of tension rollers relative to a second tension roller among the plurality of tension rollers to change a conveying position of the belt in an axial direction of the first tension roller; having The cleaning device includes: a blade-shaped first cleaning member extending in the longitudinal direction and contacting the surface of the belt; a sheet-like second cleaning member extending in the longitudinal direction and contacting the surface of the belt downstream of a contact portion between the first cleaning member and the surface of the belt in the moving direction; In a belt conveying device having A reinforcing member is provided on a surface of the belt at each of both ends in a width direction of the belt, the reinforcing member extending along a circumferential direction of the belt, A belt conveying device characterized in that, regardless of the belt conveying position in the axial direction of the first tension roller, the edges of both ends of the second cleaning member in the longitudinal direction are each positioned outside the edges of the ends of the reinforcing member on the central side in the width direction of the belt.

15. an endless belt that is stretched around a plurality of tension rollers and carries a toner image on its surface; a cleaning device extending in a longitudinal direction along a width direction substantially perpendicular to a moving direction of the surface of the belt and configured to clean the surface of the belt; a steering mechanism that tilts a first tension roller among the plurality of tension rollers relative to a second tension roller among the plurality of tension rollers to change a conveying position of the belt in an axial direction of the first tension roller; having The cleaning device includes: a blade-shaped first cleaning member extending in the longitudinal direction and contacting the surface of the belt; a sheet-like second cleaning member extending in the longitudinal direction and contacting the surface of the belt downstream of a contact portion between the first cleaning member and the surface of the belt in the moving direction; In a belt conveying device having a second cleaning member that is disposed on the outer side of the first tension roller and that is disposed on the outer side of the first tension roller, the second cleaning member being ..., the second cleaning member being disposed on the outer side of the first tension roller, the second cleaning member being disposed on the outer side of the first tension roller, the second cleaning member being disposed on the outer side of the first tension roller, the second cleaning member being disposed on the outer side of the first tension roller, the second cleaning member being disposed on the outer side of the first tension roller,

16. A belt conveying device according to any one of claims 1 to 15, an image forming section for forming a toner image on the surface of the belt; An image forming apparatus comprising:

Images