Patent Application
20190146403
This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Application No. 2017-217240 filed on Nov. 10, 2017, the contents of which are hereby incorporated by reference.
The present disclosure relates to a paper dust collecting member, and to an image forming apparatus provided with one. More particularly, the present disclosure relates to a paper dust collecting member for collecting paper dust attached to a roller, and to an image forming apparatus provided with one.
Conventionally common image forming apparatuses using an electrophotographic process typically use a process involving visualizing an electrostatic latent image formed on an image carrier such as a photosensitive drum using a developing device, transferring the visualized image (toner image) to a sheet, and then fixing the image.
The sheet is conveyed through a sheet conveying passage using a roller. Meanwhile, paper dust is generated due to friction between the sheet and the roller. In particular, a registration roller pair that corrects a skew in the sheet and conveys the sheet to an image forming portion in coordination with the timing of image formation needs to nip the sheet with a strong force, and thus is likely to generate paper dust.
There are known image formation apparatuses provided with a paper dust collecting member that contacts with the outer circumferential surface of the registration roller pair to collect paper dust on the outer circumferential surface of the registration roller pair. The paper dust collecting member includes, for example, a removing member comprising sponge that contacts with the outer circumferential surface of one roller of the registration roller pair to remove paper dust, and a holding member to which the removing member is attached. The holding member is provided with a paper dust receiving portion that receives paper dust removed by the removing member.
In this image forming apparatus, for example, when a predetermined time passes, the paper dust collecting member is pulled out in the axial direction of the registration roller pair and is replaced with a new paper dust collecting member.
A paper dust collecting member according to one aspect of the present disclosure is disposed in an apparatus main body, and removes and collects paper dust attached to a conveying roller, and is attachable along the attaching direction parallel to the axial direction of the conveying roller via an opening portion provided in a side plate of the apparatus main body. The paper dust collecting member has a removing member and a holding member. The removing member extends in the axial direction of the conveying roller and removes paper dust by being disposed so as to contact with the outer circumferential surface of the conveying roller. The holding member holds, on its mounting surface, the removing member. The removing member includes a contact surface which makes contact with the outer circumferential surface of the conveying roller. The holding member includes a protrusion portion which is disposed, on its distal end portion side, along a side surface of the removing member, and the protrusion portion protrudes in the thickness direction of the removing member beyond the contact surface of the removing member.
This and other objects of the present disclosure, and the specific benefits obtained according to the present disclosure, will become apparent from the description of embodiments which follows.
Embodiments of the present disclosure will be described below with reference to the accompanying drawings.
An image forming apparatus 1 provided with a paper dust collecting member 20 according to one embodiment of the present disclosure will be described with reference to
In the image forming portion P, a photosensitive drum (an image carrier) 2 that carries a visualized image (toner image) is disposed. The toner image formed on the photosensitive drum 2 is transferred to a sheet 6, and is then fixed to the sheet 6 by a fixing device 13. Then the sheet 6 is discharged from the image forming apparatus 1 main body. As the photosensitive drum 2 is rotated in the counter-clockwise direction in
Next, the image forming portion P will be described in detail. Around and in front (to the left in
The charging roller 3 electrostatically charges the surface of the photosensitive drum 2 uniformly, and then the exposure unit 4 irradiates it with light to form an electrostatic latent image based on an image signal on the photosensitive drum 2. The developing unit 5 has a developing roller 5a disposed so as to face the photosensitive drum 2. The developing unit 5 is charged with a predetermined amount of magnetic one-component positively charged toner by a toner container 11. The toner is fed to the surface of the photosensitive drum 2 by the developing roller 5a, and electrostatically attaches to the surface of the photosensitive drum 2 to form a toner image based on an electrostatic latent image formed through exposure to light from the exposure unit 4.
The sheet 6 to which the toner image is transferred is stored in a sheet feeding cassette 12 for storing sheets 6, and is conveyed via a sheet feeding roller 7 and a registration roller pair (conveying roller pair) 14 toward the photosensitive drum 2 on which the toner image has been formed. At a lower part of the photosensitive drum 2, by applying an electric field to the sheet 6 with a transfer roller 17 to which a predetermined transfer bias is applied, the toner image on the photosensitive drum 2 is transferred to the sheet 6.
The sheet 6 to which the toner image has been transferred is conveyed to the fixing device 13. In preparation for the subsequent formation of a new electrostatic latent image, the toner remaining on the surface of the photosensitive drum 2 after the transfer of the toner image is collected by the cleaning device 9. To the sheet 6 conveyed to the fixing device 13, the toner image is fixed under application of heat and pressure by a fixing roller 13a and a pressing roller 13b, and a predetermined image is formed on the sheet 6. Then, the sheet 6 on which an image has been formed is discharged onto a sheet discharge tray 19 by a discharge roller pair 18.
Next, the structure around the registration roller pair 14 will be described in detail.
The registration roller pair 14 is composed of, for example, a metal roller that is a driving roller and that is made of iron and a rubber roller that is a driven roller. These two rollers, by being disposed in parallel to and in pressed contact with each other, form a nip portion. The registration roller pair 14, when the distal end of the sheet 6 is put into contact with the nip portion, corrects a skew in the sheet 6. Being rotated by an unillustrated driving motor, the registration roller pair 14 conveys the sheet 6 to the image forming portion P in coordination with the timing of image formation.
As shown in
The paper dust collecting member 20 includes a removing member 21 comprising sponge or the like that collects paper dust attached to the conveying roller 14a by being disposed so as to contact with the outer circumferential surface of the conveying roller 14a, and a resin holding member 30 that holds the removing member 21. The removing member 21 is formed in the shape of a rectangular parallelopiped that extends in the axial direction of the conveying roller 14a, and is fixed to the holding member 30 with adhesive. The top surface (contact surface) 21a of the removing member 21 is a collection surface that contacts with the outer circumferential surface of the conveying roller 14a to collect paper dust.
As shown in
The holding portion 31 is so formed as to extend horizontally in parallel with the registration roller pair 14. As shown in
As shown in
Here, in a downstream-side end part in the attaching direction of the holding member 30 (the distal end portion of the holding member 30) is provided with a protrusion portion 36 that protrudes upward (in the height direction perpendicular to the attaching direction, in the thickness direction of the removing member 21). As shown in
An upper end of the protrusion portion 36 has a flat-top inverted V shape (substantially inverted V shape) including a first inclined surface 36a that is disposed in a downstream-side end part in the attaching direction and that inclines downward toward the downstream side (right side in
The downstream end (distal end) 21b of the removing member 21 in the attaching direction is disposed below the upper end (the first inclined surface 36a, the second inclined surface 36b and the level surface 36c) of the protrusion portion 36 as seen from the side perpendicular to the attaching direction (from the direction perpendicular to the plane of
The holding member 30 is provided with a lower inclined surface 37 that inclines downward from a lower end edge of the downstream-side end part (a distal end surface 30b) of the holding member 30 in the attaching direction toward the upstream side (rear end side) in the attaching direction. An upstream end (lower edge) 37a of the lower inclined surface 37 in the attaching direction is disposed on the upstream side (left side in
As shown in
As shown in
In the image forming apparatus 1, when replacing the paper dust collecting member 20, a user pulls out the paper dust collecting member 20 along the guide member 40 in the arrow A′ direction. A new paper dust collecting member 20 is then inserted in the opening portion 51 in the side wall member 50. Here, the first inclined surface 36a and the lower inclined surface 37 help the distal end portion of the paper dust collecting member 20 slide into the opening portion 51. The distal end of the removing member 21 (downstream end 21b) is protected by the protrusion portion 36, and thus it does not contact with an upper edge portion 51b of the opening portion 51.
The paper dust collecting member 20 is inserted with the bottom surface 30a sliding on the lower edge portion 51a of the opening portion 51, and is guided by the inclined portion 44 of the guide member 40 to the bottom surface portion 41. The paper dust collecting member 20 is then inserted along the bottom surface portion 41, the side surface portion 42 and the side surface portion 43, and is positioned as the boss portion 33 is inserted in a positioning hole (unillustrated) provided in the image forming apparatus 1 main body. In this way, the paper dust collecting member 20 is fitted to the image forming apparatus 1 main body.
In this embodiment, as described above, the holding member 30 has the protrusion portion 36 that is disposed, on its distal end portion side, along the side surface of the removing member 21 and that protrudes upward. The protrusion portion 36 protrudes upward beyond the top surface 21a of the removing member 21. With this, when a new paper dust collecting member 20 is inserted in the image forming apparatus 1 main body for replacement of the paper dust collecting member 20, the protrusion portion 36 protects the distal end (downstream end 21b in the inserting direction) of the removing member 21 to prevent the distal end of the removing member 21 from contacting with the opening portion 51 in the image forming apparatus 1 main body. With this, it is possible to prevent the removing member 21 itself from being damaged or the removing member 21 from coming off from the holding member 30.
As described above, the upper end of the protrusion portion 36 has the first inclined surface 36a that inclines downward toward the downstream side (distal end side) in the attaching direction. With this, when the paper dust collecting member 20 is inserted, the first inclined surface 36a guides it into the opening portion 51 in the image forming apparatus 1 main body, and this makes it easy to insert the paper dust collecting member 20 in the opening portion 51 in the image forming apparatus 1 main body.
As described above, the holding member 30 is provided with the lower inclined surface 37 that inclines downward from the lower end edge of the distal end surface 30b of the holding member 30 in the attaching direction toward the upstream side (rear end side) in the attaching direction. This makes it even easier to insert the paper dust collecting member 20 in the opening portion 51 in the image forming apparatus 1 main body.
As described above, the upstream end 37a of the lower inclined surface 37 is disposed on the upstream side (arrow A′ direction), in the attaching direction, of the downstream end 36d of the second inclined surface 36b. That is, the bottom surface 30a located at the lowest position of the holding member 30 and the level surface 36c located at the highest position of the protrusion portion 36 do not overlap in the attaching direction. With this, unlike in a case where the upstream end 37a of the lower inclined surface 37 is disposed on the downstream side (arrow A direction), in the attaching direction, of the downstream end 36d of the second inclined surface 36b (a case where the bottom surface 30a and the level surface 36c overlap in the attaching direction), it is possible to make the length in the up-down direction of the holding member 30 at any position in the attaching direction smaller than the length between the bottom surface 30a and the level surface 36c, and this helps reduce difficulty inserting the paper dust collecting member 20 in the opening portion 51 in the image forming apparatus 1 main body.
As described above, the inclination angle 936b of the second inclined surface 36b with respect to the mounting surface 31a of the holding member 30 is larger than the inclination angle 937 of the lower inclined surface 37 with respect to the mounting surface 31a of the holding member 30. With this, the length of the holding member 30 in the up-down direction at any position in the attaching direction is largest at the downstream end 36d of the second inclined surface 36b. That is, when the paper dust collecting member 20 is inserted in the opening portion 51 in the image forming apparatus 1 main body, after the downstream end 36d of the second inclined surface 36b has passes the opening portion 51, the space between the holding member 30 and the opening portion 51 becomes gradually larger, and this makes it even easier to insert the paper dust collecting member 20 in the opening portion 51.
As described above, the protrusion portion 36 has the level surface 36c that is disposed between the second inclined surface 36b and the first inclined surface 36a, and the downstream end 21b of the removing member 21 is disposed under the level surface 36c as seen from the side perpendicular to the attaching direction. With this, even if the position for attaching the removing member 21 slightly deviates in the longitudinal direction (arrow AA′ direction), the protrusion portion 36 can reliably protect the distal end of the removing member 21.
As described above, the protrusion portion 36 is disposed so as to extend from a position on the upstream side, in the attaching direction, of the downstream end 21b of the removing member 21 to the downstream side. With this, the protrusion portion 36 can reliably protect the distal end of the removing member 21.
As described above, the lower edge portion 51a of the opening portion 51 is disposed below the supporting surface 41a for supporting the paper dust collecting member 20 in the guide member 40. With this, after the protrusion portion 36 has passed through the opening portion 51, the paper dust collecting member 20 is moved upward by the guide member 40, and thus it is possible to prevent the protrusion portion 36 from contacting with the upper edge portion 51b of the opening portion 51. This makes it even easier to insert the paper dust collecting member 20 in the opening portion 51.
The registration roller pair 14 is especially prone to generate paper dust, and thus, as described above, providing the paper dust collecting member 20 of the present disclosure for removing paper dust from the registration roller pair 14 is especially effective.
The embodiments disclosed above should be understood to be in every aspect illustrative and not restrictive. The scope of the present disclosure is defined not by the description of the embodiments given above but by the appended claims, and should be understood to encompass any modifications made in the sense and scope equivalent to those of the claims.
For example, while the above embodiments deal with an example where the present disclosure is applied to a monochrome printer, this is not meant to limit the present disclosure. Needless to say, the present disclosure can be applied to various image forming apparatuses such as color printers, monochrome copiers, digital multifunction peripherals, and facsimile machines provided with a roller pair for conveying sheets and a paper dust collecting member for collecting paper dust attached to the roller pair.
For another example, while the above embodiments deal with an example where the paper dust collecting member 20 is configured to collect paper dust attached to the registration roller pair, this is in no way meant to limit the present disclosure. Instead, it is possible to configure the paper dust collecting member 20 to collect paper dust attached to a conveying roller pair other than the registration roller pair.
For another example, while the above embodiments deal with an example where the protrusion portion 36 is provided so as to extend from a position on the upstream side, in the attaching direction, of the downstream end 21b of the removing member 21 to the downstream side, this is in no way meant to limit the present disclosure. Instead, the protrusion portion 36 may be disposed so as to extend from the downstream end 21b of the removing member 21 to the downstream side.
For another example, while the above embodiments deal with an example where the first inclined surface 36a, the second inclined surface 36b, and the lower inclined surface 37 are provided in the holding member 30, this is not meant to limit the present disclosure. Instead, one or more of the first inclined surface 36a, the second inclined surface 36b, and the lower inclined surface 37 do not necessarily need to be provided.
For another example, while the above embodiments deal with an example where the level surface 36c is provided on the protrusion portion 36, the level surface 36c does not necessarily need to be provided on the protrusion portion 36.
For another example, it is possible to configure the guide member 40, for example, as in the modified example of the present disclosure shown in
Any configurations achieved by combining the configurations of the embodiments and modified examples described above are also within the technical scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-217240 | Nov 2017 | JP | national |
