Patent Application
20150277296
This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Application No. 2014-063657 filed on Mar. 26, 2014, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a cleaning device including a polishing roller that polishes, by using toner, the surface of a rotation body such as an image carrier, and to an image forming apparatus.
In an electrophotographic image forming apparatus such as a copier, an electrostatic latent image is formed on the surface of an image carrier, such as a photoconductor drum, that has been charged by a charging device. The electrostatic latent image formed on the surface of the image carrier is developed with toner, and the developed toner image is transferred onto an transfer object such as a paper sheet, so that an image is formed.
Here, a part of the toner may not be transferred to the transfer object and may remain on the surface of the image carrier. In addition, when a charging device charges the image carrier, an electric discharge is generated, and thereby discharge products may be generated and adhere to the surface of the image carrier. These adhering substances on the surface of the image carrier may hinder subsequent image formation and degrade image quality. As a result, in this type of image forming apparatus, a cleaning device is provided to remove the adhering substances from the surface of the image carrier. For example, there is known a configuration including: a cleaning member configured to remove toner from the surface of the image carrier; a polishing roller configured to polish the surface of the image carrier in the state where the removed toner has adhered to the surface of the polishing roller; and a layer thickness restricting member configured to restrict a layer thickness of the toner that has adhered to a surface of the polishing roller.
A cleaning device according to an aspect of the present disclosure includes a cleaning portion, a polishing roller, a layer thickness restricting member, and a swaying portion. The cleaning portion is configured to remove toner that has adhered to a surface of a rotation body. The polishing roller is configured to polish a surface of the rotation body by rotating in a state where a surface of the polishing roller is in contact with the surface of the rotation body and the toner removed by the cleaning portion has adhered to the surface of the polishing roller. The layer thickness restricting member is configured to restrict a layer thickness of the toner that has adhered to the surface of the polishing roller. The swaying portion is configured to cause the polishing roller to sway in an axis direction of the rotation body. The swaying portion includes: a biasing portion configured to bias the polishing roller in a biasing direction which is one of opposite directions of the axis direction of the rotation body; an undulating portion provided on the polishing roller and having a first undulating surface on a side portion thereof that is on a front side in the biasing direction; and a support portion fixed at a predetermined position, having a second undulating surface facing the first undulating surface and configured to support, on the second undulating surface, the undulating portion biased by the biasing portion.
An image forming apparatus according to another aspect of the present disclosure includes the cleaning device and an image forming portion configured to form an image based on image data.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description with reference where appropriate to the accompanying drawings. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure.
The following describes an embodiment of the present disclosure with reference to the accompanying drawings for the understanding of the disclosure. It should be noted that the following description is an example of a specific embodiment of the present disclosure and should not limit the technical scope of the present disclosure.
First, an outlined configuration of an image forming apparatus 10 in an embodiment of the present disclosure is described with reference to
As shown in
As shown in
As shown in
Specifically, as shown in
Meanwhile, in an electrophotographic image forming apparatus such as the image forming apparatus 10, a part of the toner may not be transferred to the sheet and may remain on the surface of the photoconductor drum 31. In addition, when the charging device 32 charges the photoconductor drum 31, an electric discharge is generated, and thereby discharge products may be generated and adhere to the surface of the photoconductor drum 31. These adhering substances on the surface of the photoconductor drum 31 may hinder subsequent image formation and degrade image quality. As a result, in this type of image forming apparatus, the cleaning device 6 is provided to remove the adhering substances from the surface of the photoconductor drum 31.
Next, the cleaning device 6 is described with reference to
The cleaning device 6 is configured to remove adhering substances that have adhered to the surface of the photoconductor drum 31. Specifically, as shown in
The housing 61 is a housing of the cleaning device 6, and as shown in
The cleaning portion 62 removes the toner that has adhered to the surface of the photoconductor drum 31. The cleaning portion 62 is, for example, a rubber blade formed from urethan rubber, in the shape of a blade. The cleaning portion 62 is fixed to the housing 61 in the state where, as shown in
The polishing roller 63 polishes the surface of the photoconductor drum 31 in the state where the toner removed by the cleaning portion 62 has adhered to the surface of the polishing roller 63. Specifically, as shown in
The layer thickness restricting member 64 is configured to restrict the layer thickness of the toner that has adhered to the surface of the polishing roller 63. The layer thickness restricting member 64 is, for example, a metal plate formed from SUS or the like. The layer thickness restricting member 64 is fixed to the housing 61 in the state where, as shown in
The toner conveying portion 65 conveys the toner that was scraped off by the layer thickness restricting member 64. The toner conveying portion 65 is, for example, a conveyance screw that can convey the toner in an axis direction of the polishing roller 63. The toner that was scraped off from the surface of the polishing roller 63 by the layer thickness restricting member 64 is conveyed by the toner conveying portion 65 to a toner storing container (not shown) and recovered therein, wherein the toner storing container is provided at an end of the polishing roller 63 in the axis direction.
Meanwhile, contaminants such as paper dust may enter between the polishing roller 63 and the layer thickness restricting member 64. In that case, the pressure applied from the layer thickness restricting member 64 to the surface of the polishing roller 63 changes locally, and the surface of the photoconductor drum 31 polished by the polishing roller 63 may become uneven in the axis direction of the photoconductor drum 31. On the other hand, as described in the following, the image forming apparatus 10 can remove contaminants that have entered between the polishing roller 63 and the layer thickness restricting member 64.
Next, the swaying portion 66 is described with reference to
As shown in
The first helical gear 661 is provided on the shaft of the photoconductor drum 31 such that it meshes with the second helical gear 662. The first helical gear 661 is configured to be rotated together with the photoconductor drum 31 by the power transmitted from a drive portion (not shown).
The second helical gear 662 is attached to the shaft of the polishing roller 63 at such a position to mesh with the first helical gear 661. The second helical gear 662 meshes with the first helical gear 661 and rotates together with the polishing roller 63 following the rotation of the first helical gear 661.
The teeth of the first helical gear 661 and the second helical gear 662 are inclined such that when the driving force is transmitted from the first helical gear 661, the second helical gear 662 is biased in a biasing direction 662A that is one of opposite directions of the axis direction of the photoconductor drum 31. Here, the biasing force that is applied from the first helical gear 661 to the second helical gear 662 can be defined as appropriate by, for example, the inclination angles of the teeth of the first helical gear 661 and the second helical gear 662. In this way, in the image forming apparatus 10, the configuration for causing the polishing roller 63 to rotate is used to bias the polishing roller 63, thus there is no need to provide an independent member to bias the polishing roller 63. Here, the first helical gear 661 and the second helical gear 662 are an example of the biasing portion of the present disclosure.
As shown in
As shown in
Here, the first undulating surface 663 is formed as an inclined surface that continues smoothly along the rotation direction of the polishing roller 63. Specifically, in the first undulating surface 663, the projecting portions 663A are projecting in such a way as to form a gently curved surface, and the recessed portions 663B are recessed in such a way as to form a gently curved surface. In addition, in the first undulating surface 663, a gently inclined surface is formed in each area between the projecting portion 663A and the recessed portion 663B.
As shown in
As shown in
Here, the second undulating surface 665 is formed in such a way as to come into close contact with the first undulating surface 663. That is, in the second undulating surface 665, the projecting portions 665A are recessed in such a way as to form a gently curved surface along the shape of the corresponding recessed portions 663B. In addition, in the second undulating surface 665, the recessed portions 665B are projecting in such a way as to form a gently curved surface along the shape of the corresponding projecting portions 663A. Furthermore, in the second undulating surface 665, a gently inclined surface is formed in each area between the projecting portion 665A and the recessed portion 665B, as in the first undulating surface 663.
The support portion 664 is fixed to the housing 61 at a position where the second undulating surface 665 is in close contact with the first undulating surface 663 of the second helical gear 662. As a result, when the photoconductor drum 31 rotates, the second helical gear 662 rotates while allowing the first undulating surface 663 to slide on the second undulating surface 665. With this configuration, in the image forming apparatus 10, the polishing roller 63 reciprocally moves along the axis direction in correspondence with the rotation of the second helical gear 662. That is, the polishing roller 63 is oscillated with the rotation of the second helical gear 662.
That is, as shown in
On the other hand, as shown in
In this way, in the swaying portion 66, as the second helical gear 662 rotates, the projecting portions 663A of the first undulating surface 663 slide on the second undulating surface 665. This causes the polishing roller 63 to sway in the axis direction. The swaying of the polishing roller 63 allows the contaminants such as paper dust that have been caught in the nip portion formed between the polishing roller 63 and the layer thickness restricting member 64 to drop and be removed.
Here, in the image forming apparatus 10, the first undulating surface 663 includes the pair of projecting portions 663A formed across the axial center of the polishing roller 63, and the second undulating surface 665 includes the pair of recessed portions 665B that can be fitted to the pair of projecting portions 663A. As a result, when the polishing roller 63 sways in the axis direction, the second helical gear 662 is always supported by the tips of the pair of projecting portions 663A.
Furthermore, in the image forming apparatus 10, the second undulating surface 665 includes the pair of projecting portions 665A formed across the axial center of the polishing roller 63, and the first undulating surface 663 includes the pair of recessed portions 663B that can be fitted to the pair of projecting portions 665A. As a result, when the polishing roller 63 sways in the axis direction, the second helical gear 662 is always supported also by the tips of the pair of projecting portions 665A.
That is, in the image forming apparatus 10, when the polishing roller 63 sways in the axis direction, the second helical gear 662 is always supported by four points of the pair of projecting portions 663A and the pair of projecting portions 665A. This restricts the swaying direction of the polishing roller 63 from shifting from the axis direction of the polishing roller 63, and restricts the surface of the photoconductor drum 31 polished by the polishing roller 63 from becoming uneven in the axis direction of the photoconductor drum 31. It is noted that the image forming apparatus 10 may have the following configuration. That is, a projecting portion and a recessed portion may be formed alternately at an interval of 45 degrees along the rotation direction of the polishing roller 63 on each of the first undulating surface 663 and the second undulating surface 665 such that when the polishing roller 63 sways in the axis direction, the second helical gear 662 is supported by eight points.
In the image forming apparatus 10, the first undulating surface 663 and the second undulating surface 665 are formed in such a way as to come into close contact with each other. This configuration makes it possible to effectively remove the contaminants by the impact that is generated when the second helical gear 662 is pushed back by the biasing force in the biasing direction 662A and the first undulating surface 663 and the second undulating surface 665 come into close contact with each other. In addition, when the polishing roller 63 sways in the axis direction, the contact area of the first undulating surface 663 and the second undulating surface 665 increases. As a result, the load on the projecting portions 663A and 665A that always support the second helical gear 662 is dispersed. This restricts the wearing of the projecting portions 663A and 665A.
In another embodiment, an elastic member such as a coil spring may be used to bias the polishing roller 63 in the biasing direction 662A, in the image forming apparatus 10. Here, the elastic member is another example of the biasing portion of the present disclosure.
Meanwhile, the application example of the present disclosure is not limited to the cleaning device 6 that cleans the photoconductor drum 31. For example, the present disclosure may be applied to a cleaning device that removes the adhering substances that have adhered to the surface of the charging device 32. In that case, the charging device 32 is an example of the rotation body of the present disclosure. Furthermore, the present disclosure may be applied to a cleaning device that removes the adhering substances that have adhered to the surface of the transfer roller 35. In that case, the transfer roller 35 is an example of the rotation body of the present disclosure.
It is to be understood that the embodiments herein are illustrative and not restrictive, since the scope of the disclosure is defined by the appended claims rather than by the description preceding them, and all changes that fall within metes and bounds of the claims, or equivalence of such metes and bounds thereof are therefore intended to be embraced by the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014-063657 | Mar 2014 | JP | national |
