JP6658445B2 - Cleaning device, image forming device - Google Patents

Description

  The present invention relates to a cleaning device for cleaning toner attached to an image carrier such as a transfer belt, and an image forming apparatus including the cleaning device.

  2. Description of the Related Art Conventionally, an image forming apparatus capable of forming an image by an electrophotographic method includes a cleaning device that removes toner remaining on an image carrier such as an intermediate transfer belt (see Patent Document 1). The cleaning device includes, for example, a rotating brush that rotates in contact with the image carrier, a collecting roller that electrically transfers and collects the toner attached to the rotating brush, and separates the toner from the surface of the collecting roller. It has a separation blade. The toner separated by the separation blade is collected at the bottom of the housing of the cleaning device, and is conveyed to the waste toner storage unit by a conveyance member such as a conveyance screw provided at the bottom.

JP 2007-171822 A

  In a conventional cleaning device, the rotation of the rotating brush generates an airflow in the housing along the rotating direction of the rotating brush. This airflow flows out of the housing through the gap of the opening corresponding to the image carrier. As a result, the interior of the housing becomes a negative pressure. When the inside of the housing becomes a negative pressure, air flows into the inside from the gap and a new airflow is generated. As a result, the inside of the housing collides with the airflow flowing outward and the airflow flowing into the housing from the outside, and the turbulence of the airflow occurs. This turbulence causes the removed toner contained in the rotating brush to be scattered in the housing, so that the collection efficiency when the collecting roller collects the toner from the rotating brush deteriorates. Further, the toner scattered in the housing flows out toward the image carrier through the airflow directed outward from the gap, so that there is a problem that the toner adheres to the image carrier again and the peripheral members are stained with the toner.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a cleaning device capable of effectively suppressing toner scattering in a housing, and an image forming apparatus including the cleaning device.

  A cleaning device according to one aspect of the present invention includes a brush-like rotating member, a collecting member, a housing, and a plate-like member. The rotating member removes toner adhering to the image carrier after transfer of the toner image by rotating in contact with the rotating image carrier. The collecting member electrostatically collects the toner held by the rotating member by rotating while contacting the rotating member. The housing has an opening that accommodates the rotating member and the collection member and exposes the rotating member to the image carrier. The plate-shaped member is provided at a predetermined distance upward from a bottom surface inside the casing, forms a gap between the plate-shaped member and the bottom surface, and forms a communication port on the opening side.

  An image forming apparatus according to another aspect of the present invention includes a rotatable image carrier that carries a toner image, and the cleaning device that removes toner attached to the image carrier after transfer of the toner image. .

  According to the present invention, it is possible to effectively suppress the scattering of the toner in the housing.

FIG. 1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a configuration of an image forming unit and an intermediate transfer device of the image forming apparatus according to the embodiment of the present invention. FIG. 3 is a diagram illustrating a configuration of the belt cleaning device according to the embodiment of the present invention. FIG. 4 is a partially enlarged view showing the inside of the belt cleaning device according to the embodiment of the present invention. FIG. 5 is a partially enlarged view showing a modification of the belt cleaning device according to the embodiment of the present invention. FIG. 6 is a partially enlarged view showing another modification of the belt cleaning device according to the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the embodiments described below are merely examples embodying the present invention, and do not limit the technical scope of the present invention.

[Configuration of Image Forming Apparatus 10]
First, the configuration of an image forming apparatus 10 according to an embodiment of the present invention will be described with reference to FIGS. Here, FIG. 1 is a schematic sectional view showing the configuration of the image forming apparatus 10. FIG. 2 is a schematic sectional view showing the configuration of the image forming units 31 to 34 and the intermediate transfer device 36.

  The image forming apparatus 10 is a multifunction peripheral having a plurality of functions such as a facsimile function and a copy function, in addition to a scan function of reading image data from a document and a print function of forming an image based on the image data. The present invention is applicable to an image forming apparatus such as a printer, a facsimile, and a copier.

  As shown in FIG. 1, the image forming apparatus 10 includes an ADF (automatic document feeder) 1, an image reading unit 2, an image forming unit 3, a paper feeding unit 4, and an operation display unit 5.

  The ADF 1 includes a document setting unit (not shown), a plurality of conveyance rollers, a document presser, and a paper discharge unit, and conveys a document read by the image reading unit 2. The image reading unit 2 includes a document table (not shown), a light source, a plurality of mirrors, an optical lens, and a CCD, and can read image data from a document.

  The operation display unit 5 includes a display unit such as a liquid crystal display that displays various information according to a control instruction from a control unit (not shown), and operation keys that input various information to the control unit according to a user operation. Alternatively, it has an operation unit such as a touch panel.

  The image forming unit 3 can execute an image forming process (printing process) for forming a color or monochrome image by an electrophotographic method based on the image data read by the image reading unit 2. Further, the image forming section 3 can execute the image forming processing based on image data input from an external device.

  As shown in FIGS. 1 and 2, the image forming unit 3 includes four image forming units 31 to 34, four toner containers 46, two optical scanning devices 35, an intermediate transfer device 36, a secondary transfer roller 38, and a fixing device. An apparatus 39 and a paper discharge tray 40 are provided.

  The image forming units 31 to 34 form images based on an electrophotographic method. The image forming unit 31 corresponds to yellow toner. The image forming unit 32 corresponds to cyan toner, the image forming unit 33 corresponds to magenta toner, and the image forming unit 34 corresponds to black toner. As shown in FIG. 1, the image forming units 31 to 34 are arranged in the order of yellow, cyan, magenta, and black from the front along the front-rear direction of the image forming apparatus 10.

  As shown in FIGS. 1 and 2, each of the image forming units 31 to 34 includes a photosensitive drum 41, a charging roller 42, a developing device 43, a primary transfer roller 44, and a drum cleaning device 45.

  The optical scanning device 35 forms an electrostatic latent image on each of the photosensitive drums 41 provided in the image forming units 31 to 34.

  The intermediate transfer device 36 includes an intermediate transfer belt 361 (an example of an image carrier). The intermediate transfer device 36 uses the intermediate transfer belt 361 to convey a toner image that is primarily transferred to the intermediate transfer belt 361 from each of the photosensitive drums 41 included in the image forming units 31 to 34 by the primary transfer roller 44. As shown in FIGS. 1 and 2, the intermediate transfer device 36 includes a drive roller 362, a tension roller 363, and a belt cleaning device 37 (an example of a cleaning device) in addition to the intermediate transfer belt 361.

The intermediate transfer belt 361 is an endless belt member to which a toner image formed on the surface of each of the photosensitive drums 41 provided in the image forming units 31 to 34 is transferred. The intermediate transfer belt 361 is made of a conductor having a high resistance value (for example, 10 ¹⁰ [Ω]). As shown in FIG. 1, the intermediate transfer belt 361 is stretched so as to be rotatable by a driving roller 362 and a stretching roller 363 that are spaced apart in the front-rear direction of the image forming apparatus 10.

  The driving roller 362 is driven to rotate in a rotation direction 362A by a driving force supplied from a power source (not shown) to rotate the intermediate transfer belt 361 in a predetermined direction. Thereby, the intermediate transfer belt 361 rotates along the rotation direction 36A shown in FIG.

  The belt cleaning device 37 removes extraneous matters such as toner and paper dust remaining on the surface of the intermediate transfer belt 361 after the toner image is transferred from the intermediate transfer belt 361 to the sheet. The belt cleaning device 37 will be described later.

  The secondary transfer roller 38 transfers the toner image primarily transferred on the surface of the intermediate transfer belt 361 to a sheet.

  The fixing device 39 melts and fixes the toner image transferred to the sheet by the secondary transfer roller 38 onto the sheet. For example, the fixing device 39 includes a fixing roller and a pressure roller. The fixing roller is provided in contact with the pressure roller, and heats the toner image transferred to the sheet to fix the toner image on the sheet. The pressure roller presses a sheet passing through a contact portion formed between the pressure roller and the fixing roller.

  In each of the image forming units 31 to 34, the surface of the photosensitive drum 41 is uniformly charged to a predetermined potential by the charging roller 42. Next, light based on image data is irradiated on the surface of the photosensitive drum 41 by the optical scanning device 35. As a result, an electrostatic latent image corresponding to the image data is formed on the surface of the photosensitive drum 41.

  Then, the electrostatic latent image on the photosensitive drum 41 is developed (visualized) as a toner image of a corresponding color by the developing device 43. Specifically, by supplying toner from the developing roller of the developing device 43 to the photosensitive drum 41, the electrostatic latent image on the photosensitive drum 41 is developed as a toner image. Note that, inside the developing device 43, the developer containing the toner and the carrier is frictionally charged by stirring by the stirring screw and sent to the magnetic roller, and the toner in the developer is sent from the magnetic roller to the developing roller. For example, inside the developing device 43, the toner is frictionally charged to a positive polarity. The developing device 43 is replenished with a toner of a corresponding color from a toner container 46 detachable from the image forming unit 3.

  Subsequently, the toner image formed on the photosensitive drum 41 is transferred to the intermediate transfer belt 361 of the intermediate transfer device 36 by the primary transfer roller 44. On the other hand, the toner remaining on the surface of the photosensitive drum 41 is removed by the drum cleaning device 45. For example, in the drum cleaning device 45, the toner remaining on the surface of the photosensitive drum 41 is removed by a blade-shaped cleaning member. Then, the toner removed by the cleaning member is transported to a toner storage container (not shown) by the transport screw and collected.

  As described above, in each of the image forming units 31 to 34, the toner image of the color corresponding to the intermediate transfer belt 361 of the intermediate transfer device 36 is sequentially superimposed and transferred. Then, the toner image transferred to the intermediate transfer belt 361 is transferred to a sheet supplied from the sheet feeding unit 4 by the secondary transfer roller 38.

  Thereafter, the sheet on which the toner image has been transferred is fused and fixed by the fixing device 39 to form an image, and is discharged to the discharge tray 40.

  Next, the belt cleaning device 37 will be described with reference to FIG. Here, FIG. 3 is a schematic sectional view showing the configuration of the belt cleaning device 37.

  As shown in FIG. 2, the belt cleaning device 37 is provided on the front side of the intermediate transfer device 36. The belt cleaning device 37 cleans the surface of the intermediate transfer belt 361. As shown in FIG. 3, the belt cleaning device 37 includes a housing 371 (an example of a housing), a brush roller 372 (an example of a rotating member), a collection roller 373 (an example of a collection member), a blade member 374, and a toner conveyance path 375. , A transport member 376 and a film member 377. Further, the belt cleaning device 37 includes an airflow suppressing unit 60.

  The housing 371 houses a brush roller 372, a collection roller 373, a blade member 374, and a transport member 376 therein. Further, as shown in FIG. 3, a toner conveying path 375 is formed inside the housing 371. The housing 371 has an opening 50 on a surface facing the intermediate transfer belt 361 to expose the brush roller 372 to the intermediate transfer belt 361 side.

  The brush roller 372 removes extraneous matter such as toner remaining on the intermediate transfer belt 361 after the transfer of the toner image by the secondary transfer roller 38. The brush roller 372 is a brush-like rotating member rotatably provided at a position in contact with the intermediate transfer belt 361, and is, for example, a conductive fur brush. The brush roller 372 rotates in the same rotation direction 372A as the drive roller 362 by a power source (not shown). In other words, the brush roller 372 rotates in the same rotation direction 372A as the rotation direction of the intermediate transfer belt 361.

  The collection roller 373 collects the toner removed from the surface of the intermediate transfer belt 361 by the brush roller 372. For example, the collection roller 373 is a metal roller that is rotatably provided at a position in contact with the brush roller 372. A bias voltage is applied to the collection roller 373 from the DC power supply 48. When the bias voltage is applied to the collection roller 373, current flows from the brush roller 372 to the drive roller 362 via the intermediate transfer belt 361, and furthermore, current flows from the drive roller 362 to the ground. On the other hand, as described above, since the intermediate transfer belt 361 has a high resistance value, a small amount of electric charge flows from the intermediate transfer belt 361 to the driving roller 362. Therefore, the application of the bias voltage substantially reduces the collection roller 373 and the brush. Each of the rollers 372 is charged to a predetermined potential. Specifically, the collection roller 373 has the same negative polarity as the brush roller 372, and is charged to a higher potential than the brush roller 372. The collection roller 373 is rotated by a power source (not shown) in a rotation direction 373A opposite to the driving roller 362. Thus, the collection roller 373 draws and collects the toner held by the brush roller 372 by electrostatic attraction (electrostatic force).

  The blade member 374 is provided so as to be in contact with the surface of the collection roller 373. The blade member 374 has a long shape extending in the longitudinal direction of the housing 371, that is, in the left-right direction of the image forming apparatus 10. The blade member 374 removes the toner attached to the surface of the collection roller 373. For example, the blade member 374 is a rubber plate having one end fixed to the housing 371 such that one end thereof contacts the collection roller 373. The toner removed from the collection roller 373 by the blade member 374 falls into the toner conveyance path 375 at the bottom of the housing 371.

  The toner removed by the blade member 374 is transported to the toner transport path 375. As shown in FIG. 3, the toner conveying path 375 is formed by the bottom wall 371 </ b> A at the bottom of the housing 371 at a position below the blade member 374 along the left-right direction of the image forming apparatus 10.

  The transport member 376 is rotatably provided on the toner transport path 375. The transport member 376 transports the toner in the toner transport path 375. For example, the transport member 376 is a transport screw that has fins formed spirally around the rotation axis and transports the toner along the toner transport path 375.

  The film member 377 is fixed to an upwardly extending plate-shaped support plate 371B provided on a bottom wall 371A at the bottom of the housing 371. The bottom wall 371A is substantially horizontal in the front-rear direction, and the support plate 371B extends obliquely upward while slightly tilting forward. The support plate 371B is formed integrally with the bottom wall 371A. Each of the support plate 371B and the film member 377 has a long shape extending in the longitudinal direction of the housing 371, that is, in the left-right direction of the image forming apparatus 10. The film member 377 extends further upward from the support plate 371 </ b> B, and its tip end is in contact with the outer peripheral surface of the collection roller 373. Thus, the internal space of the housing 371 is divided by the film member 377 into a space on the rear side where the brush roller 372 is provided and a toner conveying path 375 on the front side where the conveying member 376 is provided. Air cannot flow between the space on the roller 372 side and the toner conveying path 375.

  By the way, in the belt cleaning device 37, an air flow 81 (see FIG. 4) is generated in the housing 371 along the rotation direction 372A of the brush roller 372 due to the rotation of the brush roller 372. The airflow 81 is an internal airflow that passes through the inside of the housing 371 to the opening 50 side and flows out of the gap 50A below the opening 50 to the outside. As a result, the inside of the housing 371 has a negative pressure lower than the outside atmospheric pressure. When the pressure inside the housing 371 becomes negative, air flows into the inside from the gap 50A, and a new airflow 82 (see FIG. 4) is generated. As a result, the airflow 81 going outward and the airflow 82 flowing into the inside from the outside collide inside the housing 371, and the turbulence of the airflow occurs. The turbulence of the airflow causes the removed toner held by the brush roller 372 to scatter in the housing 371, so that the collection efficiency when the collection roller 373 collects the toner from the brush roller 372 deteriorates. Further, the toner scattered in the housing 371 flows out toward the intermediate transfer belt 361 along the airflow 81 directed outward from the gap 50A, so that the toner is re-adhered to the intermediate transfer belt 361, and the toner such as the photosensitive drum 41 There is a problem that the peripheral member is stained with the toner. On the other hand, in the belt cleaning device 37 according to the embodiment of the present invention, since the airflow suppressing unit 60 is provided, the turbulence of the airflow in the housing 371 is suppressed, and the scattering of the toner in the housing 371 is effectively performed. It is possible to suppress.

  Hereinafter, the configuration of the airflow suppression unit 60 will be described with reference to FIG. FIG. 4 is a partially enlarged view showing the inside of the belt cleaning device 37.

  As shown in FIG. 4, the airflow suppressing unit 60 includes a plate-shaped member 61 provided at a predetermined distance upward from a bottom wall 731 </ b> A constituting the bottom surface of the housing 731. The plate member 61 is provided in a space between the brush roller 372 and the bottom wall 371A. The plate-shaped member 61 has a long shape extending in the longitudinal direction of the housing 371, that is, in the left-right direction of the image forming apparatus 10. The plate-shaped member 61 is formed integrally with the bottom wall 371A, for example.

  The plate member 61 extends rearward from the base of the support plate 371B so as to be parallel to the bottom wall 371A, that is, to the opening 50 side. The extending direction of the plate-shaped member 61 substantially coincides with the traveling direction of the airflow 81 toward the opening 50 generated in the internal space of the housing 371 by the rotation of the brush roller 372. That is, the plate-shaped member 61 extends in the traveling direction of the airflow 81 generated below the brush roller 372. The space between the extended end of the plate-shaped member 61 and the bottom wall 371A is not closed but open. Thus, the plate-shaped member 61 forms the gap 62 at the above-described interval between the plate-shaped member 61 and the bottom wall 371A, and forms a communication port 63 communicating with the gap 62 at the end on the opening 50 side.

  Since the airflow suppressing portion 60 thus configured is provided in the housing 371, when the airflow 81 along the rotation direction 372A flows out of the gap 50A of the opening 50 to the outside, the airflow 81 from the gap 50A is affected by the negative pressure. Even if a new airflow 82 that enters the inside is generated, the airflow 82 proceeds along the bottom wall 371A and enters the gap 62 from the communication port 63 located ahead. As a result, the collision between the airflow 82 and the airflow 81 is suppressed by the plate-shaped member 61, so that the turbulence of the airflow in the housing 371 is suppressed and the scattering of the toner in the housing 371 can be prevented.

  Even if the inside of the housing 371 has a negative pressure due to the outflow of the airflow 81 to the outside, if the portion other than the communication port 63 in the gap 62 is closed, the inflow of the airflow 82 into the gap 62 is limited. ing. For this reason, as shown in FIG. 5, a through-hole 65 may be formed in the plate-shaped member 61 so as to penetrate in the up-down direction. In this case, it is preferable that the through-hole 65 is formed at a position as far away as possible from the communication port 63 to the front side (left side in the drawing) than the position near the communication port 63. That is, the through hole 65 is preferably formed at a position on the toner conveying path 375 side of the plate member 61 opposite to the opening 50. Since the through-hole 65 is formed, when the airflow 82 enters the gap 62 through the communication port 63, the air in the gap 62 flows upward from the through-hole 65, and the airflow 83 which joins the airflow 81 is generated. . As a result, the airflow 82 that has entered the inside of the housing 371 joins the airflow 83 and the airflow 81 and is returned in one direction. Thereby, the turbulence of the airflow in the housing 371 is further suppressed, and the scattering of the toner in the housing 371 can be prevented.

  Further, as shown in FIG. 6, instead of the through-hole 65, a vent 68 may be formed in the bottom wall 371 </ b> A of the housing 371 so as to allow the gap 62 and the outside to communicate with each other. In the example illustrated in FIG. 6, the vent 68 is formed at a position corresponding to the end on the toner conveying path 375 side in the gap 62. As a result, the airflow 82 that has entered the inside of the housing 371 flows out of the ventilation port 68 to the outside as the airflow 84 through the gap 62. Also in this case, the turbulence of the airflow in the housing 371 is further suppressed, and the scattering of the toner in the housing 371 can be prevented.

  The vent 68 is provided with a filter 69 such as a nonwoven fabric for capturing the floating toner contained in the airflow 84. This prevents the floating toner from flowing out together with the airflow 84.

  As described above, the embodiments of the present invention have been described, but the present invention is not limited to the above-described configuration. For example, the airflow suppressing unit 60 may include both the through hole 65 formed in the plate-shaped member 61 and the vent 68 formed in the bottom wall 371A.

10: Image forming devices 31 to 34: Image forming unit 36: Intermediate transfer device 37: Belt cleaning device 50: Opening 60: Air flow suppressing unit 62: Gap 63: Communication port 65: Through hole 68: Vent 69: Filter 371 : Housing 372: Brush roller 373: Recovery roller 374: Blade member 375: Toner transport path 376: Transport member 377: Film member

Claims (6)

A brush-like rotating member that removes toner adhered to the image carrier after transfer of the toner image by rotating in the same direction as the rotating direction of the image carrier by contacting the rotating image carrier;
A collecting member that electrostatically collects the toner held by the rotating member by rotating in contact with the rotating member;
A housing that houses the rotating member and the collection member, and has an opening that exposes the rotating member to the image carrier;
A plate-shaped member that is provided at a predetermined distance upward from the bottom surface inside the housing and forms a gap between the bottom surface and the communication port on the opening side;
The plate-shaped member is provided between the rotating member and the bottom surface such that an outer peripheral surface of the rotating member and an upper surface of the plate-shaped member face below the rotating member, and are provided below the rotating member. Extending to the opening side,
The end of the space opposite to the extending direction of the plate-shaped member is closed,
The airflow that enters the housing through the lower side of the internal airflow toward the opening generated by the rotation of the rotating member from the opening and flows into the gap along the bottom surface of the plate-shaped member A cleaning device, wherein a through-hole is formed in the plate-like member and extends vertically to penetrate the upper side and join the internal airflow. A support plate extending upward from the bottom surface,
2. The cleaning device according to claim 1, further comprising: a film member fixed to the support plate, extending further upward than an extension end of the support plate, and having a tip portion abutting on an outer peripheral surface of the collection member. 3. .   The cleaning device according to claim 1, wherein the through hole is formed at a position farthest away from the plate-shaped member in a direction opposite to the extending direction.   The cleaning device according to any one of claims 1 to 3, wherein a ventilation port that allows the gap and the outside to communicate with each other so as to allow ventilation is formed in the bottom surface of the housing.   The cleaning device according to claim 4, wherein a filter that captures the toner is provided in the vent. A rotatable image carrier for carrying a toner image,
An image forming apparatus comprising: the cleaning device according to claim 1, which removes toner attached to the image carrier after transfer of a toner image.

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