Field of the Invention
The present invention relates to a multicolor molded component used in an image forming apparatus, and a cartridge detachably attached to an apparatus main body of an image forming apparatus.
Description of the Related Art
Conventionally, a cartridge system as follows has been used in an electrophotographic image forming apparatus (hereinafter referred to as an image forming apparatus): a process unit is formed integrally into a cartridge, and this process cartridge (hereinafter referred to as a cartridge) is detachably attached to the image forming apparatus. In such a cartridge system, in order to keep a state in which a process unit is stably in contact with a photosensitive drum, a configuration in which the process unit is movably supported is used. For example, the following configuration is known: a charging roller, which is a charging unit, is supported via a bearing member that is movable in one direction, so as to be in contact with a photosensitive drum in a stable state (see Japanese Patent Application Laid-Open No. 2011-95536).
Further, the following configuration is known: a developing roller, which is a developer bearing member, is supported via a bearing member that is movable in one direction, so as to be in contact with a photosensitive drum in a stable state (see Japanese Patent Application Laid-Open No. 7-160176).
According to an aspect of the present invention, a multicolor molded component used in an image forming apparatus includes a molded portion molded with a first resin, and a bearing portion configured to be movable with respect to the molded portion, and to support a rotating member. The molded portion includes a regulation portion, and the bearing portion is formed by injection molding to be engaged with the regulation portion in such a manner as to be movable in a first direction with respect to the molded portion.
According to another aspect of the present invention, a cartridge detachably attached to an apparatus main body of an image forming apparatus, includes a process unit configured to act on an image bearing member for performing image formation, a bearing portion configured to rotatably support the process unit, and a supporting portion configured to movably support the bearing portion. The supporting portion includes a regulation portion, and the bearing portion is formed by injection molding to be engaged with the regulation portion in such a manner as to be movable in a first direction with respect to the supporting portion.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Various exemplary embodiments, features, and aspects of the invention will be described in detail below with reference to the drawings. The sizes, materials, shapes and relative arrangements of components described in these exemplary embodiments are to be appropriately changed according to a configuration of an apparatus to which the invention is applied and various conditions, and are not intended to limit the scope of the present invention to the exemplary embodiments described below.
The present invention relates to a multicolor molded component used in an image forming apparatus, and to a cartridge detachably attached to an apparatus main body of an image forming apparatus. Here, examples of the image forming apparatus include an electrophotographic image forming apparatus for forming an image on a recording material by using an image forming process of an electrophotographic type, and an ink jet recording device of a liquid discharge recording type. Examples of the electrophotographic image forming apparatus include an electrophotographic copier, an electrophotographic printer (for example, a laser beam printer and a light emitting diode (LED) printer), a facsimile device, and a word processor.
Further, the “cartridge” collectively refers to a drum cartridge that supports a photosensitive drum (electrophotographic photosensitive member), a developing cartridge that supports a developing unit, and a cartridge obtained by integrating an electrophotographic photosensitive drum and a process unit into a cartridge.
A process unit acts on an electrophotographic photosensitive drum. Examples of the process unit include a charging unit, a developing unit, a cleaning unit, and the like that act on an electrophotographic photosensitive drum, as well as a toner supply roller that applies toner to a developer bearing member (developing roller) as a developing unit, and a remaining toner amount detection unit.
The following describe an image forming apparatus and a cartridge according to a first exemplary embodiment with reference to the drawings.
[Schematic Configuration of Electrophotographic Image Forming Apparatus]
First, the entire configuration of an electrophotographic image forming apparatus will be described with reference to
As illustrated in
[Schematic Configuration of Cartridge]
Next, a configuration of the cartridge will be described with reference to
The cartridge B has a configuration in which a developing device C and a drum device D are combined so as to be relatively rotatable, and the cartridge B is detachably attached to an apparatus main body 100 of the image forming apparatus A. Here, the developing device C includes a developing unit and a development frame member 8. The developing device C includes toner (not illustrated), the developing roller 12, and the like. The development frame member 8 contains toner therein and supports the developing unit. Further, the drum device D includes components such as the photosensitive drum 7 and a cleaning blade 14, as well as a drum frame member 13 that supports these components.
Toner contained in a toner containing unit 9 of the developing device C is sent to a developing chamber 10, and a toner layer is formed on the surface of the developing roller 12 to which frictional electrification charge is applied by a developing blade 11. Then, the toner provided on the surface of the developing roller 12 is transferred onto the photosensitive drum 7 according to the latent image, whereby a toner image is formed on the photosensitive drum 7. After the toner image on the photosensitive drum 7 is transferred onto the recording material 2 by the transfer roller 4, toner remaining on the photosensitive drum 7 is scraped off by the cleaning blade 14, whereby the residual toner is collected (removed) to a waste toner reservoir 15. Thereafter, the surface of the photosensitive drum 7 is uniformly charged by a charging roller 16 as a charging member (process unit), thereby causing a state in which a latent image can be formed by the optical device 1.
[Schematic Configuration of Drum Device]
Next, the drum device D according to the present exemplary embodiment will be described with reference to
The following describes a schematic configuration of parts involved in the charging process for charging the drum device D. As illustrated in
Next, a charging method for charging the photosensitive drum 7 will be described with reference to
With this configuration, when the process cartridge B is attached to the apparatus main body 100, a main body electrode 21, which is a main body contact point member installed in the apparatus main body 100, and the contact point portion 19a of the electrode member 19 are brought into contact with each other. Subsequently, when a voltage is output to the main body electrode 21 according to a command from a controller (not illustrated) of the apparatus main body 100, a voltage is applied from the end portion 16b of the shaft of the charging roller 16 to the surface of the charging roller 16 via the electrode member 19, the compression spring 18b, and the charging roller bearing 17b. Then, the charging roller 16 can uniformly charge the surface of the photosensitive drum 7.
[Multicolor Molding Method of Bearing]
Next, a multicolor molding method of the bearing portion according to the present exemplary embodiment will be described with reference to
First, the drum frame member 13 formed with a first resin is prepared. Alternatively, as illustrated in
Here, the charging roller bearing supporting portion 13b as a part of the drum frame member 13 is used as a mold, so that the charging roller bearing 17b is molded. More specifically, a shape of contact portions 13b1 of the charging roller bearing supporting portion 13b is transferred, thereby forming a charging roller bearing 17b that includes bearing contact portions 17b1 having a shape according to the contact portions 13b1. In other words, there is formed the charging roller bearing 17b that is engaged with the rail-shaped charging roller bearing supporting portion 13b (regulation portion) for regulating the movement direction. With this configuration, if the contact portions 13b1 are formed with high accuracy, it becomes possible to form the bearing contact portions 17b1 easily with high accuracy as well. Thus, in the case of the conventional method where separate components are assembled, contact portions of the respective components need to be formed with high accuracy in order to suppress rattling between the components, but in the case where the present invention is used, the rattling between the components can be easily suppressed, and the assembling with high accuracy is enabled.
In the present exemplary embodiment, a material (for example, conductive resin) that is incompatible with a material for the drum frame member 13 and is conductive is used for forming the charging roller bearings 17a and 17b. Generally, the “compatibility” refers to that substances of a plurality of types mutually have affinity and form a mixture. In contrast, “incompatibility” generally refers to that resins of a plurality of types do not mix with one another at contact interfaces thereof. In the present exemplary embodiment, “incompatibility” refers to that resins that are integrally molded by multicolor molding are easily separable at contact interfaces thereof.
For example, in frame members, components, and the like, polystyrene (PS)-based resins are widely used. Examples of resins that are incompatible with PS-type resins when being combined therewith include polyethylene (PE), polypropylene (PP), polyamide (PA), polyethylene terephthalate (PET), and polyacetal (POM). Further, since POM, which is a crystalline resin that is widely used in a bearing member, has little compatibility unless the same materials are combined, it is sufficient that materials other than POM is used for being combined with the POM, as combinations of incompatible resins. In the case of acrylonitrile butadiene styrene resin (ABS), polycarbonate (PC), and the like, which are non-crystalline resins, the preferable combinations are those other than, for example, the combination of ABC and PC, the combination of ABS and PS, as well as combinations of the same materials. Examples of the combination of incompatible resins include the combinations of ABS and PA, PC and PE, PP, or the like, and these resins are preferably used in combination.
Further, as the conductive material, materials obtained by dispersing particular or fibrous conductive materials such as carbon fiber, other particles made of metals and the like in resins mentioned above as base material resins can be used. In the present exemplary embodiment, carbon black is used so that damage to production devices due to friction and the like should be decreased as much as possible. Here, “conductive” refers to having conductivity of 30 Ω·cm or less measured by a measurement method defined by JIS K 7194, and “non-conductive” refers to having conductivity greater than 30 Ω·cm.
In the present exemplary embodiment, as resins combined for two-color molding, a PS-based resin is used as a material for the drum frame member 13, and conductive POM containing about 10% of carbon black is used as a material for the charging roller bearing 17b. In this way, by using a combination of incompatible resins, the resins are separable at contact interfaces even after the resins are integrally molded by two-color molding, whereby the charging roller bearing 17b can be movable with respect to the drum frame member 13.
Next, a shape of the contact portion for enabling the charging roller bearing 17b molded on the drum frame member 13 by multicolor molding to be movable with respect to the drum frame member 13 will be described by way of examples, with reference to
In the present exemplary embodiment, as illustrated in
Here, as illustrated in
Alternatively, as illustrated in
In this way, a range where the charging roller bearing 17b is used (for example, a range W in the drawing) is set to a range obtainable after the movement from the molding position, and the tilt angles of the contact portions are optimized in such a manner that a desired gap can be obtained within the range, whereby rattling of the contact portions can be suppressed.
Further, the charging roller bearing supporting portion 13b of the drum frame member 13 may be configured to be free at one of the ends thereof. In this case, the facing contact portions 13b1 may be tilted so that the charging roller bearing supporting portion 13b has a shape narrowed toward the free end, whereby the charging roller bearing 17b can be prevented from dropping.
As described above, according to the first exemplary embodiment, the molding can be performed in a state where the charging roller bearing 17b is movably assembled, simultaneously with the molding of the drum frame member 13. The conventional configuration requires the step of assembling since the bearing portion is assembled with a supporting portion of a frame member or the like to be used, but herein the step of assembling the charging roller bearing 17b with the drum frame member 13 can be omitted. Further, the contact portions 13b1 of the drum frame member 13 and the bearing contact portions 17b1 of the charging roller bearing 17b are formed in shapes corresponding to each other, whereby rattling between components can be easily suppressed, and the assembling can be achieved with high accuracy.
In the first exemplary embodiment, the configuration is such that the electrode member 19 is assembled with the drum frame member 13. The configuration, however, is not limited to this, and as illustrated in
Further, in the first exemplary embodiment, the description has been given of the case where the main body electrode 21 is brought into contact with the electrode member 19. The configuration, however, is not limited to this. As illustrated in
Next, a second exemplary embodiment will be described with reference to
As illustrated in
The charging roller bearings 17a and 17b are respectively provided with compression springs 18a and 18b as urging units in such a manner that the compression springs 18a and 18b are compressible toward the photosensitive drum 7. Further, the developing roller bearings 22a and 22b are respectively provided with developing compression springs 24a and 24b as urging units in such a manner that the developing compression springs 24a and 24b are compressible toward the photosensitive drum 7. The developing roller 12 and the photosensitive drum 7 are positioned so as to face each other with a minute gap (about 100 to 400 μm). To achieve this configuration, in the present exemplary embodiment, contact ring portions (not illustrated) having an outer diameter greater than the developing roller outer diameter by the length corresponding to the minute gap are provided near both end portions in the axis line direction of the developing roller 12 in regions outside a toner layer formation region. As a result, the developing roller 12 is configured to be pressed at a predetermined pressure against the photosensitive drum 7 by pressing forces of the developing compression springs 24a and 24b in a state in which a certain minute gap being maintained with respect to the photosensitive drum 7, whereby stable developing is enabled.
[Bearing Forming Method]
The charging roller bearings 17a and 17b and the developing roller bearings 22a and 22b are formed by multicolor molding so as to be movable with respect to the bearing support members 23a and 23b. As is the case with the first exemplary embodiment, the charging roller bearings 17a and 17b and the developing roller bearings 22a and 22b are formed of resins incompatible with respect to the bearing support members 23a and 23b made of the first resin. Further, on the contact point side of the contact point with the main body contact point, conductive resins are used for the second resin for forming the charging roller bearings 17a and 17b, as well as for a third resin for forming the developing roller bearings 22a and 22b, whereby conduction between the main body contact point and the process unit is ensured. In a case where the same material is used for the second resin and the third resin, these components can be formed by the same injection molding device. This is preferable since there is no need to provide a plurality of injection molding devices.
As described above, according to the second exemplary embodiment, molding is integrally performed as a multicolor molded component 30 having a plurality of bearing portions movable with respect to the bearing support members 23a and 23b, a step of assembling a plurality of bearing portions can be omitted.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2014-176309, filed Aug. 29, 2014, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2014-176309 | Aug 2014 | JP | national |
Number | Name | Date | Kind |
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5884124 | Karakama | Mar 1999 | A |
6070029 | Nishiuwatoko | May 2000 | A |
20110222903 | Kishi | Sep 2011 | A1 |
20120207506 | Honobe | Aug 2012 | A1 |
20120269545 | Morita | Oct 2012 | A1 |
20130022368 | Takarada | Jan 2013 | A1 |
20130272753 | Fukasawa | Oct 2013 | A1 |
Number | Date | Country |
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H07-160176 | Jun 1995 | JP |
2011-95536 | May 2011 | JP |
Number | Date | Country | |
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20160062309 A1 | Mar 2016 | US |