This patent application is based on and claims priority under 35 U.S.C. §119(a) to Japanese Patent Application No. 2015-100866, filed in Japan on May 18, 2015, and Japanese Patent Application No. 2015-161800, filed in Japan on Aug. 19, 2015, and the disclosure of each is hereby incorporated by reference in their entirety.
Technical Field
Embodiments of the present application generally relate to a cleaning device and an image forming apparatus, such as, a copier, a printer, a facsimile machine, a plotter, or a multifunction peripheral (MFP) device including a toner conveyance device.
Description of the Related Art
Typically, an electrostatic latent image formed on a photoconductor as an image bearer is visualized as a toner image by a developing device. The toner image is transferred to a transfer material such as paper, and fixed as a visualized image in an image forming apparatuses such as printers, copiers, facsimile machines, and MFTs having those capabilities. An un-transferred toner on the photoconductor is leaned from the photoconductor by a cleaning blade which contacts to the photoconductor and conveyed to the developing device or a waste toner container by a conveyance member such as a screw or a coil.
As image forming apparatuses are being made smaller, a temperature in the image forming apparatus is increased, which deteriorates a fluidity of toner used in the image forming apparatus. As fluidity deteriorates, enhancing an ability of toner conveyance is desired. Waste toner, which is collected and stored, is agitated and cultivated by an agitator made of elastic plate with rotation of the conveyance member in order to prevent toner from clogging in the conveyance path. A free end of the agitator is arranged in an area around the conveyance member where the waste toner is accumulated. Thereby the stored waste toner is agitated and cultivated by the agitator.
Further, image forming apparatuses may include a plurality of scraping pieces or arm members at an end of the agitator. The agitator is vibrated by interlocking with the driving of the conveyance member.
A cleaning device in accordance with the present disclosure comprises a cleaning member to clean toner on an image bearer, a toner conveyance to convey toner cleaned by the cleaning member, and an agitator that vibrate due to rotation of the toner conveyance, the agitator including a bent portion which is to contact to the toner conveyance.
The accompanying drawings are included to provide further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the specification, serve to explain the principle of the invention.
Embodiments of the present disclosure are described below with reference to the accompanying drawings. However, the disclosure of this patent specification is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner and achieve a similar result.
In a cleaning device which includes an agitator having a plate-shaped piece at an end of the agitator, there is a possibility that the plate-shaped piece is deformed, which may reduce the vibration of the agitator. A reduction in the vibration of the agitator may then lead to toner clogging of the toner bridge. Further, deformation of the agitator may lead to toner leakage onto a transfer material.
Embodiment of the present application may reduce occurrence of the toner bridge and toner clogging.
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views thereof. Referring to
Image forming apparatus 100 is a tandem type apparatus including a developing unit arranged around a photoconductor as an image bearer, a toner cartridge arranged above the developing unit, and four image forming sections.
Image forming apparatus 100 includes four toner cartridges 41 (41a, 41b, 41c and 41d), developing units 31 (31a, 31b, 31c and 31d) and photoconductors 22 (22a, 22b, 22c, and 22d) combined to the developing units 31 for respective colors (yellow, magenta, cyan and black).
Cleaning blade 23 (23a, 23b, 23c and 23d) is a cleaning member which cleans un-transferred toner after a primary transfer process is performed. Charging roller 21 (21a, 21b, 21c and 21d) is a charger which is in contact with the photoconductor 22 and charging roller 21 is arranged around the photoconductor 22. Photoconductor unit 20 (20a, 20b, 20c and 20d) includes charging roller 21 and photoconductor 22. Optical writing head 36 (36a, 36b, 36c and 36d) has an LED, and the optical writing head 36 exposes the photoconductor 22.
An intermediate transfer unit includes an intermediate transfer belt 28, a driving roller 26 and a driven roller 27. The intermediate transfer belt 28 contacts and separates from the photoconductors 22, and intermediate transfer belt 28 is stretched and moves between the driving roller 26 and the driven roller 27. A primary transfer roller 29 (29a, 29b, 29c and 29d) is arranged so as to oppose to each of the photoconductors 22a, 22b, 22c and 22d via the intermediate transfer belt 28.
A bias voltage of negative potential is applied from a bias power to a core bar of developing roller 3 (32a, 32b, 32c and 32d), which are each respectively a part of the developing unit 31 (31a, 31b, 31c and 31d). The bias voltage of negative potential of direct current is applied from the other bias power to each of the charging roller 21. An image forming part includes the developing unit 31, the photoconductor 22, the cleaning blade 23 and the charging roller 21.
Image forming apparatus 100 further includes each image part 20 for a respective color, and with image parts 20 it is possible to form a color image. For example, in the first image forming part 20a, the cleaning blade 23a cleans un-transferred toner which remains on a surface of the photoconductor 22a. The charging roller 21a charges the surface of the photoconductor 22a to initialize and make uniform a high potential. LED of the optical writing head 36a selectively exposes the photoconductor 22a based on the image data. Thereby, an electrostatic latent image comprising a low-potential part whose potential is attenuated by exposure and a high-potential part by initialized is formed onto the surface of the photoconductor 22a which is charged to a uniform high potential.
The developing unit 31a forms the toner image by transferring the toner to the low-potential part of the electrostatic latent image. The photoconductor 22a transfers the toner to the intermediate transfer belt 28 by rotationally conveying the toner image. The second image forming part 20b, the third image forming part 20c and the forth image forming part 20d each perform the same as first image forming part 20a, thereby generating and conveying a composed color image, which is transferred to a recording medium, such as paper, which is conveyed to second transfer part by a second transfer roller 39.
Referring to
When the waste toner is collected, there may be two types of arrangement. In a first arrangement, the surface of the photoconductor 22 rotates so as to be close to the cleaning blade 23 from upper side. In a second arrangement, the surface of the photoconductor 22 rotates no as to be close to the cleaning blade 23 from lower side. In the first arrangement, the un-transferred toner is cleaned from the photoconductor 22 by the cleaning blade 23 and the toner accumulates in a back side of the cleaning blade 23 (i.e., the opposite side of the photoconductor 22). Since a free end of the agitator 53 is arranged between the cleaning blade 23 and conveyance 52, the agitator 53 is vibrated, and the accumulated toner is loosened and agitated. Thereby it is possible to enhance an ability of conveying the toner via conveyance 52.
On the other hand, in the first arrangement in which the surface of the photoconductor 22 rotates no as to be close to the cleaning blade 23 from the upper side, the operability is poor because the transfer part is arranged above the process cartridge 200, and the process cartridge 200 is detached from only horizontal direction in exchanging the process cartridge 200. It is impossible to detach the process cartridge 200 from the image forming apparatus 100 in vertical direction.
In the second arrangement, the surface of the photoconductor 22 rotates so as to be close to the cleaning blade 23 from lower side. The process cartridge 200 is detachable from the upper side of the image forming apparatus 100 by arranging the transfer part below the process cartridge.
In the arrangement, un-transferred toner which cleaned from the photoconductor 22 by the cleaning blade 23 falls in direction of gravity. The un-transferred toner accumulates between the conveyance 52 and a seal 51. The seal is attached to the cartridge case 11 so as to prevent the waste toner, which is stored inside a waste toner containing part of the cleaning device, from leaking.
Un-transferred toner is conveyed to the collecting container outside the process cartridge by the conveyance 52 with being loosed and agitated by the agitator 53. The shape of the conveyance 52 may be a spiral such as screw type or coil type so as to convey toner smoothly.
Agitator 53 may be composed of PET (poly ethylene terephthalate). However, agitator may be composed of another elastically deformable material, such as a thin stainless plate.
Typically, in a elastically plate-shape material, the material deforms at the contact portion of the conveyance 52, which reduces a vibration of the end of an agitator. Agitator 53, however, includes the bent part 534 between the second surface 532 and the third surface 533. The bent part 534 is harder than plate-shape part. As a result, agitator 53 sufficiently vibrates when the bent part 534 is near the contact portion of the conveyance 52.
The un-transferred toner is cleaned by cleaning blade 23, from a surface of agitator 53 between lines A and B, and the toner is accumulated near a back side of the seal 51, in the area between lines B and C. The end of the agitator 53 is arranged lower than the upper end of the seal 51. Thereby, the un-transferred toner at the back side of the seal 51 is agitated and loosened by vibrating of the agitator 53. This reduces bridging of the toner. The agitated and loosened waste toner T is conveyed to the waste toner container by conveyance 52. In addition, the end of the agitator 53 is arranged at a back side of the seal 51, which reduces a likelihood of damage to the surface of the photoconductor 22 by contacting the end of the agitator 53 to the surface of the photoconductor 22.
As illustrated in
Modified structures of the agitator 53 are illustrated in
In
In
As illustrated in
As illustrated in
In many devices, the conveyance is driven in interlock with the photoconductor by, for example, a gear connection. In such cases, when the photoconductor is rotated in a reverse direction relative to a normal direction to clean the toner at the end of cleaning member, the conveyance is also rotated in the reverse direction.
The agitator 60 includes a plurality of arm members, and the end of agitator 60 is bent at an angle away from the arm members and conveyance 52. The conveyance 52 is connected to a gear 65, and rotates in same direction to the gear 65. When the conveyance 52 is rotated by the gear 65 in a rotational direction R1, the spiral wing of the conveyance 52 contacts the agitator 60 at the contact portion A and the spiral wings move along a direction D. Further discussion of contact portion A will be discussed with respect to
As shown in
In this case, there is a possibility that the agitator 60 is caught in the spiral wing of the conveyance 52 and noise is generated, in addition, that the agitator 60 is damaged by involving the rotation of the conveyance 52. In typical agitators, a clutch is provided between the conveyance 52 and the gear 65 so as to stop a reverse rotation of the conveyance 52. However, adding the clutch cause increasing cost and machine size. Agitator 60, however, may be rotated in the reverse direction without being caught in conveyance 52 and without causing damage to conveyance 52 and agitator 60.
The agitator 70 contacts the conveyance 52 at the contact portion A of the agitator 70 when the conveyance 52 rotates in the normal direction (rotational direction R1). The agitator 70 contacts the conveyance 52 at the contact portion B of the agitator 70 when the conveyance 52 rotates in the reverse direction (rotational direction R2). A spiral wing of conveyance 52 moves along a direction S when the conveyance 52 rotates in the reverse direction, as illustrated in
The agitator 70 includes a gradient α between the contact portion B and the direction S of the spiral wing of the conveyance 52. A range of the gradient α may be from 60 degrees to 120 degrees, and more preferably, the gradient α is 90 degrees. When the gradient is within 60 degrees and 120 degrees, the agitator 70 intersects approximately at a right angle to the direction S of the spiral wing of the conveyance 52 when the conveyance 52 rotates in the reverse direction, so that the agitator 70 is not caught by the conveyance 52. Such a configuration reduces the generation of noise by agitator 70.
When conveyance 52 is rotated in a rotational direction R1 the agitator 70 contacts the conveyance 52 at the contact portion A. Therefore the contact portion A has a straight shape.
In some different shape configurations of the conveyance 52, such as a different spiral direction of the conveyance 52, noise is generated at the contact portion A, and the end of the conveyance 52 is vibrated at the contact portion B. In this case, it is possible to correspond that a position of the contact portion A and the contact portion B reverse.
As described above, the agitator 70 includes a gradient α at least at one of the contact portions to the conveyance 52, which reduces the generation of noise by the agitator 70. Further, such a configuration reduces a cost and size of a cleaning device because it is not necessary to add additional components, such as a clutch. Thus, agitator 70 removes toner which accumulates the end of the cleaning member by being rotated in the reverse direction even when the conveyance rotates interlocked with photoconductor.
The agitator 80 includes a straight part 81, an oblique part 82 and a bent part 536. The straight part 81 is orthogonal to an axis direction of the conveyance 52. The oblique part 82 is inclined to the axis direction of the conveyance 52. When the conveyance 52 is rotated in the rotational direction R2 by the gear 65, the spiral wing of the conveyance 52 contacts the agitator 80 at the oblique part 82. On the other side, the conveyance 52 is rotated in the rotational direction R2, which is the reverse direction of R1, and the spiral wing contacts the agitator 80 at the straight part 81.
The agitator 80 contacts the conveyance 52 at the straight part 81 when the conveyance 52 is rotated in the rotational direction R1, and the agitator 80 contacts the conveyance 52 at the oblique part 82 when the conveyance 52 is rotated in the rotational direction R2. In this embodiment, since the agitator 80 contacts the spiral wing of the conveyance 52 in approximately orthogonal direction, the agitator 80 is not caught by the conveyance 52 a generation of noise by the agitator 80 is reduced.
As illustrated in
When the conveyance 52 rotates in the rotational direction R2, the agitator 90 contacts the spiral wing of the conveyance 52 at the second oblique part 92b and the third oblique part 92c. Thereby, the agitator 90 is not caught by the conveyance 52 because the agitator 90 contacts the spiral wing of the conveyance 52 in an approximately intersecting direction when the conveyance 52 rotate in the reverse direction. Such a configuration reduces a generation of the noise.
In addition, the agitator 90 includes the first oblique part 92a. Thereby, a processability of the agitator 90 is increased because a distance between the first oblique 92a and the third oblique 92c, which is next to first oblique 92a, is increased. Furthermore, the agitator 90 includes the straight part 91, which is a length in the longitudinal direction of the end side of the agitator 90. When straight part 91 is of a large length, an area of an end side of agitator 90 is increased and a strength of the agitator 90 is increased.
The agitator 90 further includes a gradient side (i.e., oblique part) at a part of contact portion to the conveyance 92, and it is possible to suppress a generation of noise when the conveyance 52 rotates in the reverse direction. In addition, processability and strength are enhanced by effectively combing the straight part and the oblique part of the end of the agitator 90.
Therefore, agitator 90 removes toner which accumulates at end of the cleaning blade when the photoconductor rotates in the reverse direction even when the conveyance rotates in conjunction with the photoconductor.
These embodiments are but examples. Moreover, variations and modifications may be made without departing from the scope of the present disclosure.
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2015-100866 | May 2015 | JP | national |
2015-161800 | Aug 2015 | JP | national |
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