JP6731281B2 - Cleaning device, transfer device and image forming device - Google Patents

Description

The present invention relates to a cleaning device, and more particularly to, for example, a cleaning device that removes toner remaining on the outer peripheral surface of a transfer belt suspended by a plurality of suspension rollers so as to be capable of rotating. Further, the present invention relates to a transfer device and an image forming apparatus that include a cleaning device.

An example of a conventional cleaning device is disclosed in Patent Document 1. The cleaning device (belt cleaning unit) of Patent Document 1 includes a brush roller, a collecting roller, a conveying screw (collecting screw), and the like. The brush roller has an outer peripheral portion that abuts the outer peripheral surface of the intermediate transfer belt, is driven to rotate in a predetermined rotation direction, and removes and collects toner remaining on the outer peripheral surface of the intermediate transfer belt after transfer. The collecting roller is a cylindrical metal member for further collecting the toner collected by the cleaning roller, and is rotationally driven in contact with the cleaning roller. The brush roller and the collecting roller are rotated in opposite directions, that is, follow rotation is performed in the facing direction (contacting position) facing each other in the same direction. Then, the residual toner collected from the intermediate transfer belt by the brush roller, the collecting roller and the like is conveyed to the waste toner container by the conveying screw.

JP, 2015-25950, A

In the technique of Patent Document 1, the brush roller and the collecting roller are made to follow the rotation in the same direction at their abutting positions. Therefore, the removal performance of removing the toner adhering to the brush roller by the collection roller is not sufficient, and the brush roller may be clogged. Further, since the collecting roller for further collecting the toner collected by the brush roller is provided, the cleaning device becomes large.

Therefore, a main object of the present invention is to provide a novel cleaning device, transfer device and image forming apparatus.

Another object of the present invention is to provide a cleaning device, a transfer device and an image forming device capable of appropriately preventing clogging of a brush roller.

A first aspect of the present invention is a cleaning device that is provided on an upper portion of a transfer belt suspended by a plurality of suspension rollers so as to be capable of rotating, and removes toner remaining on the outer peripheral surface of the transfer belt. A brush roller that is provided so as to contact the outer peripheral surface and is rotated in a predetermined rotation direction to scrape off the toner remaining on the outer peripheral surface of the transfer belt, a conveying screw that conveys the toner scraped off from the transfer belt, A cleaning blade that is provided downstream of the brush roller in the orbiting direction of the transfer belt so as to contact the outer peripheral surface of the transfer belt and scrapes off the toner remaining on the outer peripheral surface of the transfer belt. It is provided on the upstream side of the opposing roller provided so as to face the blade and the brush roller in the orbital movement direction of the transfer belt, and presses the outer peripheral surface of the transfer belt to increase the contact area of the transfer belt with respect to the opposing roller. The conveying screw is provided with a pressing roller , the outer peripheral portion of which is provided so as to abut the outer peripheral portion of the brush roller, and is rotated in the counter direction with respect to the rotating direction of the brush roller. Between the transfer belt and the transfer belt, a position where the tip of the cleaning blade contacts the transfer belt in the orbiting direction is downstream of the central position of the contact area between the transfer belt and the opposing roller. In the cleaning device, the outer peripheral portion of the brush roller contacts the outer peripheral surface of the transfer belt at a position upstream of the central position .

In the first aspect, the cleaning device includes the brush roller and the conveying screw, and removes the toner remaining on the outer peripheral surface of the transfer belt after the toner image is transferred to the sheet. The brush roller scrapes off the toner remaining on the outer peripheral surface of the transfer belt by contacting the outer peripheral portion of the brush roller so as to bite into the outer peripheral surface of the transfer belt and being rotated in a predetermined rotation direction. The transport screw is a transport member that transports the toner scraped off from the transfer belt to the toner collection box, and has a rotating shaft and a spiral blade formed on the outer peripheral surface of the rotating shaft. The conveying screw is provided so that its outer peripheral portion abuts on the outer peripheral portion of the brush roller, and is rotated in the counter direction with respect to the rotating direction of the brush roller. That is, the brush roller and the conveying screw have the same rotation direction, and rotate in opposite directions at their abutting positions.
Further, in the first invention, the cleaning device is provided above the transfer belt, and is provided so as to contact the outer peripheral surface of the transfer belt on the downstream side of the brush roller in the orbital movement direction of the transfer belt. A cleaning blade for scraping off the toner remaining on the outer peripheral surface of the belt is further provided, and the conveying screw is arranged between the brush roller and the cleaning blade at a predetermined distance from the transfer belt.
Further, according to the first aspect of the invention, the opposing roller is provided so as to face the cleaning blade with the transfer belt interposed therebetween, and the brush roller is provided upstream of the brush roller in the orbital movement direction of the transfer belt to press the outer peripheral surface of the transfer belt. The pressure roller is further provided.
In the first invention, the tip of the cleaning blade comes into contact with the transfer belt at a position downstream of the center position of the contact area between the transfer belt and the opposing roller in the orbital movement direction of the transfer belt. The outer peripheral portion of the brush roller contacts the outer peripheral surface of the transfer belt at a position on the upstream side.

According to the first aspect of the present invention, the outer peripheral portion of the conveying screw is brought into contact with the outer peripheral portion of the brush roller, and the conveying screw is rotated in the counter direction with respect to the rotating direction of the brush roller. It can be properly removed, and the clogging of the brush roller can be appropriately prevented. Therefore, the cleaning performance of the brush roller can be maintained for a long period of time.

Further, since the conveying screw functions as a cleaning member for removing the toner attached to the brush roller, it is not necessary to separately provide a cleaning member, and the cleaning device can be downsized.

Further , according to the first aspect of the present invention, a certain amount of toner can be appropriately held in the space formed by the intermediate transfer belt, the brush roller, the cleaning blade, and the conveying screw. Therefore, it is possible to prevent the cleaning blade from being reversed and to suppress the load applied to the cleaning blade and the intermediate transfer belt.

Further, according to the first aspect , the contact area of the transfer belt with the facing roller can be increased, so that waviness or bending of the transfer belt can be suppressed. Therefore, since the linear pressure of the cleaning blade with respect to the intermediate transfer belt can be made constant, the residual toner on the transfer belt can be appropriately removed.

A second invention is according to the first invention, and the pressing roller is at a position closer to the brush roller than a suspension roller provided at a position closest to the upstream side of the pressing roller at least in the orbiting direction of the transfer belt. Is arranged as.

According to the second aspect , it is possible to more appropriately suppress the waviness or the bending of the transfer belt.

A third invention is according to the first or the second invention, and the brush roller is arranged at a position closer to the opposing roller than the pressing roller in the rotational movement direction of the transfer belt.

A fourth invention is according to any one of the first to third invention, the brush roller is at least partially disposed to overlap the opposed roller in the circular movement direction of the transfer belt.

According to the fourth aspect of the present invention, by disposing the brush roller in the vicinity of the facing roller, which has less waviness or bending of the transfer belt, the brush roller can be brought into contact with the intermediate transfer belt substantially uniformly over the entire length thereof. it can. Therefore, the residual toner on the transfer belt can be appropriately scraped off by the brush roller.

A fifth invention is according to the first to fourth any one of the, amount of engagement against the transfer belt of the brush roller is set larger than the bite amount for transfer belt pressing roller. That is, since the outer peripheral portion of the brush roller is fibrous and soft and easily bent, the biting amount of the brush roller with respect to the transfer belt is set larger than that of the pressing roller.

According to the fifth aspect , the residual toner on the transfer belt can be appropriately scraped off by the brush roller.

A sixth invention is according to any of the first to fifth pressing roller has a sponge layer on the outer periphery.

According to the sixth aspect , the pressing roller has a function as a cleaning member that removes the toner remaining on the outer peripheral surface of the transfer belt, in addition to the function of suppressing waviness or bending of the transfer belt.

A seventh invention is according to any of the first to sixth transport screw rotates downwards at the contact position with the brush roller.

According to the seventh aspect , the toner removed from the brush roller is likely to fall downward, and the toner is prevented from scattering.

An eighth invention is provided with a transfer belt suspended by a plurality of suspension rollers so as to be capable of rotating around, and a cleaning device according to any one of the first to seventh inventions for removing the toner remaining on the outer peripheral surface of the transfer belt. , A transfer device.

A ninth invention is an image forming apparatus including the transfer device according to the eighth invention.

Also in the eighth and ninth inventions, the same effects as those of the first to seventh inventions can be obtained, and the clogging of the brush roller can be appropriately prevented.

According to the present invention, the outer peripheral portion of the conveying screw is brought into contact with the outer peripheral portion of the brush roller, and the conveying screw is rotated in the counter direction with respect to the rotation direction of the brush roller. It can be removed, and the clogging of the brush roller can be appropriately prevented. Therefore, the cleaning performance of the brush roller can be maintained for a long period of time.

Further, since the conveying screw functions as a cleaning member for removing the toner attached to the brush roller, it is not necessary to separately provide a cleaning member, and the cleaning device can be downsized.

The above-mentioned objects, other objects, features and advantages of the present invention will become more apparent from the detailed description of the embodiments below with reference to the drawings.

It is an illustration figure which shows schematic structure of the image forming apparatus provided with the cleaning apparatus which is 1st Example of this invention. FIG. 2 is a perspective view showing a transfer device included in the image forming apparatus of FIG. 1. FIG. 3 is a plan view showing the transfer device of FIG. 2, showing a state in which a frame of the cleaning device is removed. It is sectional drawing which shows schematic structure of the transfer apparatus of FIG. It is an illustration figure which shows the cleaning device which is 1st Example of this invention, (A) is a top view which shows a cleaning device, (B) is a top view which shows the cleaning device with the frame removed. .. It is a bottom view which shows the cleaning device of FIG. It is sectional drawing which shows schematic structure of the cleaning apparatus of FIG. It is a top view showing a cleaning device which is a 2nd example of the present invention, and shows the state where a frame was removed. FIG. 9 is a bottom view showing the cleaning device of FIG. 8. It is sectional drawing which shows schematic structure of the cleaning apparatus of FIG. It is sectional drawing which shows schematic structure of the transfer apparatus provided with the cleaning apparatus which is 3rd Example of this invention.

[First embodiment]
Referring to FIG. 1, a cleaning device 10 according to a first embodiment of the present invention is used in an image forming device 100 that forms an image on a sheet by an electrophotographic method. As will be described later in detail, the cleaning device 10 includes a brush roller 74, a cleaning blade 76, a conveying screw 82, and the like, and is provided in the transfer device 42 included in the image forming apparatus 100, and is transferred after the toner image is transferred onto the sheet. The toner remaining on the outer peripheral surface of the belt (intermediate transfer belt 54) is removed.

First, the basic configuration of the image forming apparatus 100 will be schematically described. In this embodiment, the image forming apparatus 100 is a multi-function peripheral (MFP) having a copy function, a printer function, a scanner function, a facsimile function, and the like.

As shown in FIG. 1, the image forming apparatus 100 includes an apparatus main body 12 including an image forming unit 30 and the like, and an image reading apparatus 14 arranged above the apparatus main body 12.

The image reading device 14 includes a document placing table 16 formed of a transparent material. A document pressing cover 18 is openably and closably mounted above the document placing table 16 via a hinge or the like. The document pressing cover 18 is provided with an ADF (automatic document feeder) 24 for automatically feeding the documents placed on the document tray 20 one by one to the image reading position 22. Although illustration is omitted, on the front surface side of the document placing table 16, an operation unit such as a touch panel and operation buttons for receiving an input operation such as a print instruction by a user is provided.

Further, the image reading device 14 includes an image reading unit 26 including a light source, a plurality of mirrors, an imaging lens, a line sensor, and the like. The image reading unit 26 exposes the surface of the document with a light source, and guides the reflected light reflected from the surface of the document to the imaging lens by a plurality of mirrors. Then, the reflected light is imaged on the light receiving element of the line sensor by the imaging lens. The line sensor detects the brightness and chromaticity of the reflected light formed on the light receiving element, and generates image data based on the image of the document surface. As the line sensor, a CCD (Charge Coupled Device), a CIS (Contact Image Sensor), or the like is used.

A control unit 28 including a CPU and a memory, an image forming unit 30, and the like are built in the apparatus body 12. The control unit 28 transmits a control signal to each part of the image forming apparatus 100 including the transfer device 42 in response to an input operation to an operation unit such as a touch panel, and causes the image forming apparatus 100 to perform various operations. The control unit 28 is also a control unit of the transfer device 42 and the cleaning device 10 in order to control the entire image forming apparatus 100.

The image forming unit 30 includes an exposure unit 32, a developing device 34, a photoconductor drum 36, a photoconductor cleaner unit 38, a charger 40, a transfer device 42, a fixing unit 44, and the like, and a paper feed tray 48 or a manual paper feed tray 50. An image is formed on the sheet conveyed from the sheet, and the sheet on which the image is formed is discharged to the sheet discharge tray 52. Image data read by the image reading unit 26, image data transmitted from an external computer, or the like is used as image data for forming an image on a sheet.

The image data handled by the image forming apparatus 100 corresponds to four color images of black (K), cyan (C), magenta (M), and yellow (Y). For this reason, each of the developing device 34, the photoconductor drum 36, the photoconductor cleaner unit 38, and the charger 40 is provided four by four so as to form four types of latent images corresponding to each color, and four images are formed by these. The station is configured.

The photoconductor drum 36 is an image carrier in which a photosensitive layer is formed on the surface of a cylindrical substrate having conductivity, and the charger 40 is a member that charges the surface of the photoconductor drum 36 to a predetermined potential. is there. The exposure unit 32 is configured as a laser scanning unit (LSU) including a laser emitting unit, a reflection mirror, and the like, and exposes the surface of the charged photosensitive drum 36 to expose an electrostatic latent image corresponding to image data. An image is formed on the surface of the photosensitive drum 36. The developing device 34 visualizes the electrostatic latent image formed on the surface of the photosensitive drum 36 with toner of four colors (YMCK). Further, the photoconductor cleaner unit 38 removes toner remaining on the surface of the photoconductor drum 36 after development and image transfer.

2 to 4 together with FIG. 1, the transfer device 42 includes an intermediate transfer belt 54, a driving roller 56, a driven roller 58, four intermediate transfer rollers 60, a secondary transfer roller 62, and a cleaning device 10. , Arranged above the photoconductor drum 36.

The intermediate transfer belt 54 is a flexible endless belt, and is made of synthetic resin, rubber, or the like appropriately mixed with a conductive material such as carbon black. The intermediate transfer belt 54 is suspended by a plurality of suspension rollers provided in parallel with each other, and in the first embodiment, a drive roller 56 and a driven roller 58 which are laterally arranged at a predetermined interval, and the outer peripheral surface on the lower side thereof. The lower surface is arranged so as to contact the outer peripheral surface of the photosensitive drum 36. Then, the intermediate transfer belt 54 is rotated in a predetermined direction (counterclockwise in FIGS. 1 and 4) as the drive roller 56 is rotationally driven.

The drive roller 56 is provided rotatably around its axis by a drive unit (not shown). The driven roller 58 rotates with the circular movement of the intermediate transfer belt 54 and applies a constant tension to the intermediate transfer belt 54 to prevent the intermediate transfer belt 54 from loosening.

The intermediate transfer rollers 60 are arranged at positions facing the respective photosensitive drums 36 with the intermediate transfer belt 54 interposed therebetween. At the time of image formation, a predetermined voltage (primary transfer voltage) is applied to the intermediate transfer roller 60, so that a transfer electric field is formed between the photosensitive drum 36 and the intermediate transfer belt 54. Then, due to the action of the transfer electric field, the toner image formed on the outer peripheral surface of the photosensitive drum 36 is transferred to the outer peripheral surface of the intermediate transfer belt 54.

The secondary transfer roller 62 is provided so as to press the intermediate transfer belt 54 with the drive roller 56. When an image is formed, a predetermined voltage (secondary transfer voltage) is applied to the secondary transfer roller 62, so that a transfer electric field is formed between the intermediate transfer belt 54 and the secondary transfer roller 62. Then, due to the action of the transfer electric field, the toner image formed on the outer peripheral surface of the intermediate transfer belt 54 is formed on the paper while the paper passes through the transfer nip region between the intermediate transfer belt 54 and the secondary transfer roller 62. It is transferred (secondary transfer).

After the toner image is transferred onto the paper, the toner remaining on the outer peripheral surface of the intermediate transfer belt 54 is removed by the cleaning device 10 and collected in the toner collection box 72. However, although the cleaning device 10 mainly removes the residual toner, it can also remove the paper dust and the like adhering to the outer peripheral surface of the intermediate transfer belt 54.

The cleaning device 10 includes a brush roller 74, a cleaning blade 76, a conveying screw 82, and the like, and is provided on the upper portion of the intermediate transfer belt 54, that is, a substantially linear portion between the drive roller 56 and the driven roller 58 (after transfer to a sheet). It is provided on the return side portion of. Further, the toner recovery box 72 is provided on the front side of the image forming apparatus 100 and stores the toner conveyed from the cleaning device 10 by the conveying screw 82. The specific configuration of the cleaning device 10 will be described later.

Returning to FIG. 1, the fixing unit 44 includes a heat roller 64 and a pressure roller 66, and is arranged above the secondary transfer roller 62. The heat roller 64 is set to have a predetermined fixing temperature, and when the paper passes through the nip area between the heat roller 64 and the pressure roller 66, the toner image transferred onto the paper is melted, After being mixed and pressed, the toner image is thermally fixed on the paper.

In the apparatus main body 12 as described above, a sheet for feeding the paper from the paper feed tray 48 or the manual paper feed tray 50 to the paper discharge tray 52 via the registration roller 68, the secondary transfer roller 62 and the fixing unit 44. One sheet transport path L1 is formed. Further, when performing double-sided printing on a sheet, the sheet that has finished single-sided printing and has passed through the fixing unit 44 is transferred to the first sheet conveyance path L1 on the upstream side of the secondary transfer roller 62 in the sheet conveyance direction. A second sheet transport path L2 for returning is formed. A plurality of transport rollers 70 for supplementarily applying a propulsive force to the sheet are provided in the first sheet transport path L1 and the second sheet transport path L2.

When performing single-sided printing (image formation) in the apparatus main body 12, the paper is guided one by one from the paper feed tray 48 or the manual paper feed tray 50 to the first paper conveyance path L1 and is conveyed by the conveyance rollers 70 to the registration rollers 68. Be transported to. Then, the registration roller 68 conveys the paper to the secondary transfer roller 62 (transfer nip portion) at the timing when the front end of the paper and the front end of the image information on the intermediate transfer belt 54 are aligned, and the toner image is transferred onto the paper. To be done. Then, by passing through the fixing unit 44 (fixing nip portion), the unfixed toner on the sheet is melted by heat and fixed, and the sheet is discharged onto the sheet discharge tray 52.

On the other hand, when performing double-sided printing, when single-sided printing is completed and the trailing edge of the sheet that has passed through the fixing unit 44 reaches the conveyance roller 70 near the discharge tray 52, the conveyance roller 70 is rotated in the reverse direction. As a result, the paper runs backward and is guided to the second paper transport path L2. The sheet guided to the second sheet transport path L2 is transported by the transport roller 70 through the second sheet transport path L2, and is guided to the first sheet transport path L1 on the upstream side of the registration roller 68 in the sheet transport direction. At this point, the front and back of the paper are reversed, and then the paper passes through the secondary transfer roller 62 and the fixing unit 44 to print on the back of the paper.

Subsequently, the configuration of the cleaning device 10 will be described with reference to FIGS. As described above, the cleaning device 10 is a device that removes the residual toner remaining on the outer peripheral surface of the intermediate transfer belt 54 after the toner image formed on the outer peripheral surface of the intermediate transfer belt 54 is transferred to the sheet. It is arranged above the transfer belt 54. The cleaning device 10 includes components such as a brush roller 74, a cleaning blade 76, a facing roller 78, a sub blade 80, and a conveying screw 82. These components are integrally held by a frame 84 or the like in a predetermined arrangement mode.

The brush roller 74 is a roller in which a large number of brush bristles are provided upright on the shaft portion, and the drive roller 56 and the drive roller 56 are arranged so that the outer peripheral portion (the tip of the brush bristles) contacts the outer peripheral surface of the intermediate transfer belt 54. It is provided parallel to the driven roller 58. Then, the brush roller 74 is rotated in a predetermined rotation direction by a drive source (not shown) to mechanically scrape and remove the toner remaining on the outer peripheral surface of the intermediate transfer belt 54. In the first embodiment, the brush rollers 74 are rotated in the follow direction (clockwise in FIG. 7) with respect to the rotational movement direction of the intermediate transfer belt 54, that is, the brush rollers 74 are directed in the same direction at their abutting positions. Rotate. However, the brush roller 74 may be rotated so as to be counter-rotated with respect to the rotational movement direction of the intermediate transfer belt 54.

The brush roller 74 may be a conductive brush, and by providing a predetermined potential difference between the intermediate transfer belt 54 and the brush roller 74, the toner remaining on the outer peripheral surface of the intermediate transfer belt 54 is brushed. It is also possible to mechanically scrape with the roller 74 and to draw it to the brush roller 74 side by an electric action.

The cleaning blade 76 is a long rectangular plate-like elastic member, and is provided so as to extend parallel to the brush roller 74 at a position near the downstream side of the brush roller 74 in the revolving direction of the intermediate transfer belt 54. The cleaning blade 76 is provided so that the edge on the long side contacts the outer peripheral surface of the intermediate transfer belt 54 in the counter direction, and the cleaning roller 76 is provided on the outer peripheral surface of the intermediate transfer belt 54 where the brush roller 74 cannot be scraped off. The residual toner is dammed and mechanically scraped to remove it.

The facing roller 78 is provided so as to face the cleaning blade 76 with the intermediate transfer belt 54 interposed therebetween. That is, the edge of the cleaning blade 76 on the long side contacts the outer peripheral surface of the intermediate transfer belt 54 in the area contacting the opposing roller 78. The opposing roller 78 causes the cleaning blade 76 to contact the intermediate transfer belt 54 substantially uniformly over the entire length thereof.

The brush roller 74 described above is arranged so that at least a part of the brush roller 74 overlaps the facing roller 78 in the circumferential movement direction of the intermediate transfer belt 54. That is, the opposing roller 78 is provided so as to contact the brush roller 74 with the intermediate transfer belt 54 interposed therebetween. Since the wavy or bending of the intermediate transfer belt 54 during the circular movement is small in the vicinity of the opposing roller 78, by disposing the brush roller 74 so that at least a part of the brush roller 74 overlaps the opposing roller 78, The roller 74 can be brought into contact with the intermediate transfer belt 54 substantially uniformly over the entire length thereof. Therefore, the residual toner on the intermediate transfer belt 54 can be appropriately scraped off by the brush roller 74.

The sub-blade 80 is a long rectangular plate-like member, and is provided so as to extend parallel to the brush roller 74 at a position near the upstream side of the brush roller 74 in the circumferential movement direction of the intermediate transfer belt 54. The cleaning blade 76 is provided so as to come into contact with the outer peripheral surface of the intermediate transfer belt 54 in the follow direction, and the toner scraped off from the intermediate transfer belt 54 by the brush roller 74 and the cleaning blade 76 is transferred to the intermediate transfer belt 54. The toner is received so as not to leak (return) to the upstream side in the orbital movement direction of.

The transport screw 82 is a transport member that transports the toner scraped from the intermediate transfer belt 54 by the brush roller 74 and the cleaning blade 76 to the toner recovery box 72. The conveyance screw 82 has a cylindrical rotation shaft and a spiral blade in which a long flat plate is spirally wound around the outer peripheral surface of the rotation shaft, and is provided in parallel with the brush roller 74. The outer peripheral portion (the tip of the spiral blade) of the conveying screw 82 comes into contact with the outer peripheral portion of the brush roller 74 so as to bite into the outer peripheral portion of the brush roller 74. To be rotated. That is, the brush roller 74 and the conveying screw 82 rotate in the same direction (clockwise in FIG. 7) and rotate in opposite directions at their abutting positions. As described above, the outer peripheral portion of the conveying roller 82 is bitten into the outer peripheral portion of the brush roller 74 and brought into contact with the outer peripheral portion of the brush roller 74 in the counter direction, so that the toner removing force is increased and the toner attached to the brush roller 74 is appropriately removed. Can be removed. In other words, in the first embodiment, the conveying screw 82 is used as a cleaning member that removes the toner attached to the brush roller 74.

Further, in the first actual example, at the contact position between the brush roller 74 and the carrying screw 82, the carrying screw 82 rotates downward. As a result, the toner removed from the brush roller 74 easily falls downward (in the space 86 described later), and the toner is prevented from scattering.

Further, in the first embodiment, the conveying screw 82 is arranged between the brush roller 74 and the cleaning blade 76 and above the intermediate transfer belt 54 with a predetermined interval. That is, a small space 86 having a predetermined height is formed between the intermediate transfer belt 54 and the conveying screw 82.

In such a cleaning device 10, after the toner image is transferred onto the sheet at the transfer nip portion, the toner remaining on the outer peripheral surface of the intermediate transfer belt 54 is first scraped off by the brush roller 74. Further, the cleaning blade 76 scrapes off the toner that has not been scraped off by the brush roller 74. The toner scraped off by the brush roller 74 and the cleaning blade 76 is temporarily stored in a space 86 formed by the intermediate transfer belt 54, the brush roller 74, the cleaning blade 76 and the conveying screw 82. Then, the toner stored in the space 86 is transported to the toner recovery box 72 at any time by the transport screw 82 located above the space 86. That is, a constant amount of toner is always held in the space 86. Further, a part of the toner scraped off from the intermediate transfer belt 54 adheres (is collected) to the brush roller 74, but the toner adhered to the brush roller 74 is removed by the conveying screw 82 to collect the toner. It is transported to the box 72.

Here, at the contact position between the intermediate transfer belt 54 and the cleaning blade 76, the toner scraped off from the intermediate transfer belt 54 acts as a lubricant, so if there is no toner accumulation at the tip of the cleaning blade 76, friction will occur. May increase and the cleaning blade 76 may be inverted. On the other hand, if too much toner is accumulated, the load on the cleaning blade 76 and the intermediate transfer belt 54 will be large. Therefore, the amount of toner accumulated at the tip of the cleaning blade 76 needs to be set to an appropriate amount.

On the other hand, in the first embodiment, as described above, a certain amount of toner is appropriately held in the space 86 formed by the intermediate transfer belt 54, the brush roller 74, the cleaning blade 76 and the conveying screw 82. Therefore, it is possible to prevent the cleaning blade 76 from being reversed and to suppress the load applied to the cleaning blade 76 and the intermediate transfer belt 54. Further, by disposing the brush roller 74 and the cleaning blade 76 close to each other, a proper amount of toner can be held in the space 86 without enlarging the space 86. That is, the size of the cleaning device 10 can be reduced, and a defect such as the reversal of the cleaning blade 76 can be appropriately prevented.

As described above, according to the first embodiment, the outer peripheral portion of the conveying screw 82 is brought into contact with the outer peripheral portion of the brush roller 74, and the conveying screw 82 is rotated in the counter direction with respect to the rotating direction of the brush roller 74. Therefore, the toner adhering to the brush roller 74 can be properly removed, and the clogging of the brush roller 74 can be appropriately prevented. Therefore, the cleaning performance of the brush roller 74 can be maintained for a long period of time.

Further, since the transport screw 82 functions as a cleaning member that removes the toner adhering to the brush roller 74, it is not necessary to separately provide a cleaning member, and the cleaning device 10, by extension, the transfer device 42 and the image forming device 100 can be downsized. ..

Further, since the cleaning device 10 is arranged above the intermediate transfer belt 54, it is possible to reduce the width of the transfer device 42 and the image forming apparatus 100 in the width direction.

Furthermore, since the conveying screw 82 is disposed between the brush roller 74 and the cleaning blade 76 with a predetermined distance from the intermediate transfer belt 54, the intermediate transfer belt 54, the brush roller 74, the cleaning blade 76 and the conveying blade are conveyed. A certain amount of toner can be appropriately held in the space 86 formed by the screw 82. Therefore, it is possible to prevent the cleaning blade 76 from being reversed and to suppress the load on the cleaning blade 76 and the intermediate transfer belt 54.

[Second Embodiment]
Next, a cleaning device 10 which is a second embodiment of the present invention will be described with reference to FIGS. The second embodiment differs from the first embodiment described above in that a pressing roller 90 is further provided. Since the configuration of the other parts is the same, the parts common to those in the above-described first embodiment are designated by the same reference numerals, and overlapping description will be omitted or simplified.

As shown in FIGS. 8 to 10, the cleaning device 10 of the second embodiment is provided on the upstream side of the brush roller 74 in the revolving direction of the intermediate transfer belt 54, and the outer peripheral surface of the intermediate transfer belt 54 is moved downward. It further comprises a pressing roller 90 for pressing to. The pressing roller 90 is a driven roller that rotates with the circular movement of the intermediate transfer belt 54, and is provided so as to extend parallel to the brush roller 74. In this way, by pressing the outer peripheral surface of the intermediate transfer belt 54 using the pressing roller 90, the intermediate transfer belt 54 is wound around the outer peripheral surface of the counter roller 78, and the intermediate transfer belt 54 is wound around the counter roller 78. The contact area becomes large. As a result, waviness or bending of the intermediate transfer belt 54 is suppressed, so that the cleaning blade 76 and the brush roller 74 contact the intermediate transfer belt 54 more uniformly over the entire length thereof (that is, the linear pressure is constant). You can Therefore, the residual toner on the intermediate transfer belt 54 can be appropriately removed.

Further, in the second embodiment, the pressing roller 90 is provided at least at the closest position on the upstream side of the pressing roller 90 in the revolving direction of the intermediate transfer belt 54 (the driving roller 56 in the second embodiment). The brush roller 74 is located closer to the brush roller 74 than the brush roller 74. That is, the pressing roller 90 is arranged as close to the opposing roller 78 as possible. This makes it possible to more appropriately suppress waviness or bending of the intermediate transfer belt 54.

Further, in the second embodiment, the brush roller 74 is arranged at a position closer to the counter roller 78 than the pressing roller 90 in the revolving direction of the intermediate transfer belt 54. The amount of biting of the brush roller 74 with respect to the intermediate transfer belt 54 is set to be larger than the amount of biting of the pressing roller 90 with respect to the intermediate transfer belt 54. Since the outer peripheral portion of the brush roller 74 is fibrous and soft and easily bent, the amount of the bite of the brush roller 74 with respect to the intermediate transfer belt 54 is made larger than that of the pressing roller 90, so that the toner remaining on the outer peripheral surface of the intermediate transfer belt 54 is removed. It can be scraped off firmly by the brush roller 74.

As described above, also in the second embodiment, as in the first embodiment, the outer peripheral portion of the conveying screw 82 is brought into contact with the outer peripheral portion of the brush roller 74, and the conveying screw 82 is rotated in the rotation direction of the brush roller 74. Since it is rotated in the counter direction, the toner adhering to the brush roller 74 can be appropriately removed, and the clogging of the brush roller 74 can be appropriately prevented.

Further, according to the second embodiment, since the pressing roller 90 is provided on the upstream side of the brush roller 74 in the revolving direction of the intermediate transfer belt 54, the corrugation of the intermediate transfer belt 54 at the position where the cleaning device 10 is arranged or Bending can be suppressed. Therefore, the cleaning blade 76 and the brush roller 74 can be brought into contact with the intermediate transfer belt 54 more uniformly over the entire length thereof.

As the pressing roller 90, a roller having a sponge layer on the outer peripheral portion can be used. As a result, the pressing roller 90 has a function as a cleaning member that removes the toner remaining on the outer peripheral surface of the intermediate transfer belt 54, in addition to the function of suppressing waviness or bending of the intermediate transfer belt 54.

[Third Embodiment]
Next, with reference to FIG. 11, a cleaning device 10 according to a third embodiment of the present invention will be described. The cleaning device 10 of the third embodiment is different from the first embodiment described above in that it is arranged on the outer peripheral surface of the side portion (lateral side) of the intermediate transfer belt 54. Since the configuration of the other parts is basically the same, the parts common to the above-described first embodiment are denoted by the same reference numerals, and the duplicate description will be omitted or simplified.

As shown in FIG. 11, the cleaning device 10 of the third embodiment includes a brush roller 74, a cleaning blade 76, a conveying screw 82, and the like, and presses the intermediate transfer belt 54 with the driven roller 58. It is arranged on a side portion of the intermediate transfer belt 54. In the third embodiment, since the driven roller 58 is arranged at the position where the brush roller 74 and the cleaning blade 76 face each other, the counter roller 78 is not provided.

Also in the third embodiment, similarly to the first embodiment, the outer peripheral portion of the conveying screw 82 is brought into contact with the outer peripheral portion of the brush roller 74, and the conveying screw 82 is counter-rotated with respect to the rotating direction of the brush roller 74. Since the toner is attached to the brush roller 74, the toner adhered to the brush roller 74 can be properly removed, and the clogging of the brush roller 74 can be appropriately prevented.

In the case of the transfer device 42 or the image forming apparatus 100 in which the photosensitive drum 36 and the like are arranged above the intermediate transfer belt 54, the cleaning device 10 may be arranged below the intermediate transfer belt 54.

Further, in each of the above-described embodiments, the intermediate transfer belt 54 is illustrated as the transfer belt cleaned by the cleaning device 10, but the present invention is not limited to this. For example, the cleaning device 10 can also remove the toner remaining on the outer peripheral surface of the secondary transfer belt.

Furthermore, in each of the above-described embodiments, the image forming apparatus 100 is exemplified by a multi-function peripheral including a copying machine, a facsimile, a printer, and the like. However, the image forming apparatus 100 may be a copying machine, a facsimile, a printer, or the like, or It may be a multi-function machine that combines at least two of these.

Further, all of the specific numerical values, materials, shapes, and the like mentioned above are merely examples, and can be appropriately changed according to the needs such as product specifications.

10... Cleaning device 30... Image forming part 42... Transfer device 54... Intermediate transfer belt 62... Secondary transfer roller 74... Brush roller 76... Cleaning blade 78... Opposing roller 82... Conveying screw 90... Pressing roller 100... Image forming device

Claims (9)

A cleaning device, which is provided on an upper portion of a transfer belt suspended by a plurality of suspension rollers so as to be capable of rotating, and removes toner remaining on the outer peripheral surface of the transfer belt ,
A brush roller whose outer peripheral portion is provided so as to contact the outer peripheral surface of the transfer belt and which is rotated in a predetermined rotation direction to scrape off the toner remaining on the outer peripheral surface of the transfer belt.
A conveying screw that conveys the toner scraped from the transfer belt,
A cleaning blade, which is provided so as to contact the outer peripheral surface of the transfer belt on the downstream side of the brush roller in the revolving direction of the transfer belt and scrapes off the toner remaining on the outer peripheral surface of the transfer belt,
A facing roller provided so as to face the cleaning blade with the transfer belt interposed therebetween, and
A pressing roller that is provided on the upstream side of the brush roller in the revolving direction and that increases the contact area of the transfer belt with respect to the opposing roller by pressing the outer peripheral surface of the transfer belt,
The conveying screw is provided so that the outer peripheral portion thereof comes into contact with the outer peripheral portion of the brush roller, and is rotated in the counter direction with respect to the rotating direction of the brush roller,
The transfer screw is disposed between the brush roller and the cleaning blade with a predetermined distance from the transfer belt.
In the revolving movement direction, the position where the tip of the cleaning blade contacts the transfer belt is a position downstream of the center position of the contact area between the transfer belt and the counter roller, and the outer peripheral portion of the brush roller. The cleaning device is configured such that the position where the abutting contact with the outer peripheral surface of the transfer belt is located upstream of the central position . The pressing roller is arranged to than the suspension roller provided at the closest position upstream of the pressing roller in at least before distichum times moving direction is the position of the brush roller close, according to claim 1, wherein Cleaning device. The brush roller, before the in distichum times the movement direction than the pressing roller will be disposed in the opposed roller close, the cleaning apparatus according to claim 1 or 2 wherein. The brush roller, before at least a part is arranged so as to overlap the opposed roller in distichum times the movement direction, the cleaning device according to any one of claims 1 to 3. The amount of engagement against the transfer belt of the brush roller, the amount of engagement against the transfer belt of the pressing roller is set larger than the cleaning device according to any one of claims 1 to 4. The pressing roller has a sponge layer on the outer periphery, the cleaning apparatus according to any one of claims 1 to 5. The cleaning device according to any one of claims 1 to 6 , wherein the transport screw rotates downward at a contact position with the brush roller. The transfer belt is suspended so as to be circularly moved by a plurality of suspension rollers, and a cleaning device according to any one of claims 1 to 7 wherein removing the toner remaining on the outer peripheral surface of the transfer belt, a transfer device. An image forming apparatus comprising the transfer device according to claim 8 .

Images