This patent application is based on and claims priority pursuant to 35 U.S.C. §119 to Japanese Patent Application No. 2012-180983, filed on Aug. 17, 2012, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.
1. Technical Field
Exemplary aspects of the present disclosure generally relate to a shutter assembly for opening and closing an outlet of a powder container from which powder is discharged.
2. Description of the Related Art
In known electrophotographic image forming apparatuses, a toner cartridge storing toner and a process unit including image forming components such as a photosensitive drum and a developing roller are constituted as separate units to facilitate replacement and maintenance. Generally, the toner cartridge includes an outlet from which toner inside thereof is discharged when supplying toner. The outlet is formed detachably attachable relative to an inlet provided to the process unit. When removing the toner cartridge from the process unit, the toner is spilled from the outlet of the toner cartridge. In view of this, a known toner cartridge is provided with a shutter to prevent the toner from leaking from the outlet. Furthermore, to prevent toner leakage more reliably, in one approach, two shutters are provided.
Although advantageous, when employing two shutters such as an internal shutter and an external shutter that open and close independently, only the internal shutter may accidentally open upon replacement of the toner cartridge. If the internal shutter is opened while the external shutter is closed, the toner leaked from the outlet accumulates between the internal shutter and the external shutter. When the external shutter opens in this state, the accumulated toner between these shutters is spilled out, causing contamination of the toner cartridge and hands of users and technicians, hence complicating replacement of the toner cartridge. Such spilled toner may also stick to devices in the image forming apparatus, causing errors during operation.
In view of the above, there is an unsolved need for a shutter assembly that prevents an internal shutter from opening while an external shutter is closed. In an aspect of this disclosure, there is provided an improved a shutter assembly for opening and closing an outlet of a powder container from which powder is discharged. The shutter assembly includes an internal shutter and an external shutter. The internal shutter is movable between a first position at which the internal shutter closes the outlet, a third position at which the internal shutter opens the outlet, and a second position between the first position and the third position, at which the internal shutter is movable to the third position while closing the outlet. The internal shutter includes a contact member. The external shutter is movable between a closed position at which the external shutter closes the outlet and an open position at which the external shutter opens the outlet, and includes an interlocking member to contact the contact member of the internal shutter to move the internal shutter. As the external shutter is moved from the closed position to the open position, the internal shutter is moved from the first position to the second position in conjunction with movement of the external shutter.
The aforementioned and other aspects, features and advantages would be more fully apparent from the following detailed description of illustrative embodiments, the accompanying drawings and the associated claims.
A more complete appreciation of the disclosure and many of the attendant advantages thereof will be more readily obtained as the same becomes better understood by reference to the following detailed description of illustrative embodiments when considered in connection with the accompanying drawings, wherein:
A description is now given of illustrative embodiments of the present invention. It should be noted that although such terms as first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, it should be understood that such elements, components, regions, layers and/or sections are not limited thereby because such terms are relative, that is, used only to distinguish one element, component, region, layer or section from another region, layer or section. Thus, for example, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of this disclosure.
In addition, it should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. Thus, for example, as used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Moreover, the terms “includes” and/or “including”, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
In describing illustrative embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. 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 have the same function, operate in a similar manner, and achieve a similar result.
In a later-described comparative example, illustrative embodiment, and alternative example, for the sake of simplicity, the same reference numerals will be given to constituent elements such as parts and materials having the same functions, and redundant descriptions thereof omitted.
Typically, but not necessarily, paper is the medium from which is made a sheet on which an image is to be formed. It should be noted, however, that other printable media are available in sheet form, and accordingly their use here is included. Thus, solely for simplicity, although this Detailed Description section refers to paper, sheets thereof, paper feeder, etc., it should be understood that the sheets, etc., are not limited only to paper, but include other printable media as well.
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and initially with reference to
As illustrated in
More specifically, each of the process units 1Y, 1M, 1C, and 1BK includes a photosensitive drum 2, a charging roller 3, a developing device 4, a cleaning blade 5, and so forth. The photosensitive drum 2 serves as a latent image bearing member. The charging roller 3 serves as a charging device to charge the surface of the photosensitive drum 2. The developing device 4 develops a latent image formed on the photosensitive drum 2 into a visible image known as a toner image. The cleaning blade 5 serves as a cleaning device that cleans the surface of the photosensitive drum 2. An exposure device 6 serving as a latent image forming device is disposed opposite each of the photosensitive drums 2. The exposure device 6 forms a latent image on the surface of the photosensitive drum 2. According to the present illustrative embodiment, an LED unit is employed as the exposure device 6.
Toner cartridges 30 are detachably disposed above the respective developing devices 4. The toner cartridges 30 store powder toners used for image formation. The toner cartridges 30 store toners of respective colors corresponding to the colors of toners in the developing devices 4. When the amount of toner in the developing device 4 drops below a predetermined amount, the toner cartridge 30 supplies toner to the developing device 4. It is to be noted that, although the image forming apparatus of the present illustrative embodiment employs a single-component developing agent including only toner particles, a two-component developing agent including toner particles and carrier particles may be employed.
A transfer device 7 is disposed substantially below the photosensitive drums 2. The transfer device 7 includes a belt-type intermediate transfer member (hereinafter referred to as intermediate transfer belt) 8 serving as a latent image bearing member. The intermediate transfer belt 8 is formed into an endless loop and entrained around a plurality of support rollers. More specifically, the intermediate transfer belt 8 is entrained around a drive roller 9 and a driven roller 10. As the drive roller 9 rotates in the counterclockwise direction in
Primary transfer rollers 11 are disposed inside the looped intermediate transfer belt 8, opposite each of the photosensitive drums 2. The primary transfer rollers 11 press the inner surface of the intermediate transfer belt 8, opposite each of the photosensitive drums 2 so that the intermediate transfer belt 8 contacts the photosensitive drums 2, thereby forming primary transfer nips therebetween. The primary transfer rollers 11 are connected to a power source and supplied with a certain direct current (DC) voltage and/or an alternating current (AC) voltage.
A secondary transfer roller 12 serving as a secondary transfer mechanism is disposed outside the loop formed by the intermediate transfer belt 8, opposite the drive roller 9. The secondary transfer roller 12 presses the outer circumferential surface of the intermediate transfer belt 8, thereby forming a secondary transfer nip therebetween. Similar to the primary transfer rollers 11, the secondary transfer roller 12 is connected to a power source and supplied with a certain DC voltage and/or an AC voltage.
A belt cleaning device 13 is disposed substantially at the right end of the looped intermediate transfer belt 8, to clean the surface of the intermediate transfer belt 8. Although not illustrated, a waste toner conveyance tube extends from the belt cleaning device 13 and connects to an opening of a waste toner container 14 disposed below the transfer device 7.
A sheet tray 15 storing a stack of recording media P, a sheet feed roller 16, and so forth are disposed at the bottom of the image forming apparatus 100. A recording medium P includes, but is not limited to, thick paper, postcards, envelopes, normal paper, thin paper, coated paper such as coated paper and art paper, tracing paper, an OHP sheet, and an OHP film.
A pair of sheet output rollers 17 and a sheet output tray 18 are disposed at the upper portion of the image forming apparatus 100. The pair of sheet output rollers 17 outputs the recording medium P outside the image forming apparatus 100 onto the sheet output tray 18.
In the image forming apparatus 100, a sheet path R, along which the recording medium P is delivered from the sheet tray 15 to the sheet output tray 18 via the secondary transfer nip, is formed. A pair of registration rollers 19 is disposed in the sheet conveyance path R upstream from the secondary transfer roller 12 in the direction of conveyance of the recording medium P. The pair of registration rollers 19 serves as timing rollers that measure a timing at which the recording medium P is fed to the secondary transfer nip. A fixing device 20 for fixing an unfixed toner image on the recording medium P is disposed downstream from the secondary transfer roller 12 in the direction of conveyance of the recording medium P.
Still with reference to
As the image forming operation is initialized, the photosensitive drums 2 of the process units 1Y, 1M, 1C, and 1BK are rotated in the clockwise direction in
The electrostatic latent images formed on the photosensitive drums 2 are developed with toner supplied from the developing devices 4 into visible images, known as toner images.
After the image forming operation is started, the drive roller 9, around which the intermediate transfer belt 8 is entrained, starts to rotate in the direction of arrow in
Subsequently, in conjunction with rotation of the photosensitive drums 2, the toner images on the photosensitive drums 2 arrive at the primary transfer nips in which the toner images on the photosensitive drums 2 are transferred onto the intermediate transfer belt 8 such that they are superimposed one atop the other. Accordingly, a composite toner image is formed. Residual toner, not having been transferred and thus remaining on the photosensitive drums 2 is removed by the cleaning blades 5.
At the bottom of the image forming apparatus 100, as the sheet feed roller 16 rotates, picking up the top sheet of the recording media P in the sheet tray 15 and feeds it to the sheet path R. Conveyance of the recording medium P fed to the sheet path R is temporarily stopped by the pair of the registration rollers 19.
Subsequently, the pair of the registration rollers 19 is rotated again to feed the recording medium P to the secondary transfer nip in appropriate timing such that the recording medium P is aligned with the composite toner image formed on the intermediate transfer belt 8 arriving at the secondary transfer nip. At this time, the secondary transfer roller 12 is supplied with a transfer voltage having a polarity opposite the charge polarity of toner of the toner image on the intermediate transfer belt 8, thereby forming a transfer electric field at the secondary transfer nip. Due to the transfer electric field, the toner image on the intermediate transfer belt 8 is transferred onto the recording medium P.
Residual toner, not having been transferred, thus remaining on the intermediate transfer belt 8 is removed by the belt cleaning device 13. The removed toner is sent to the waste toner container 14.
After the composite toner image is transferred onto the recording medium P, the recording medium P is delivered to the fixing device 20 in which heat and pressure are applied to the recording medium P, thereby fixing the composite toner image on the recording medium P. After the toner image is fixed on the recording medium P, the recording medium P is discharged and stacked onto the sheet output tray 18 by the pair of sheet output rollers 17.
The above description pertains to the image forming operation for forming a multiple-color image on a recording medium. However, the image forming operation is not limited thereto. The image forming apparatus 100 may form a single-color image using one of process units 1Y, 1M, 1C, and 1BK, or an image consisting of at least two colors using at least two process units.
According to the illustrative embodiment, the image forming apparatus 100 includes a top cover 101 serving as a first cover and a middle cover 102 serving as a second cover. The top cover 101 is disposed at the upper portion of the image forming apparatus 100. The middle cover 102 is disposed substantially below or interior to the top cover 101. The top cover 101 is rotatable about a shaft 103 and openably closable relative to the image forming apparatus 100. The middle cover 102 is rotatable about a shaft 104 and openably closable relative to the image forming apparatus 100.
The middle cover 102 includes a toner cartridge mounting portion 120 (shown in
Opening the top cover 101 as illustrated in
Furthermore, as illustrated in
With reference to
As illustrated in
The container 33 includes a powder storage compartment 34 storing toner to be supplied and a powder transport portion 35 inside the container 33. The powder storage compartment 34 and the powder transport portion 35 are separated by a semicylinder-shaped separator 36. The powder storage compartment 34 includes an agitator 37 to mix the toner. The powder transport portion 35 includes a conveyor screw 38 to transport the toner.
The container 33 includes an outlet 39 which is an opening from which toner transported by the conveyor screw 38 is discharged. The outlet 39 is connected to a connecting opening 105 formed in the middle cover 102 via a sealing member 106. The connecting opening 105 is connected to an inlet 40 which is an opening formed at the upper portion of the developing device 4. In other words, as the toner cartridge 30 is mounted on the middle cover 102, the outlet 39 and the inlet 40 are connected via the connecting opening 105, and the toner can be supplied from the toner cartridge 30 to the developing device 4.
The toner cartridge 30 includes a shutter assembly to open and close the outlet 39. More specifically, the shutter assembly has two shutters including an internal shutter 41 and an external shutter 42. The internal shutter 41 is disposed inside the outlet 39. The external shutter 42 is disposed outside the outlet 39.
The internal shutter 41 is a cylindrical-shaped rotary shutter disposed inside the powder transport portion 35. The internal shutter 41 includes an opening 43 formed in the circumference thereof. The internal shutter 41 is movable between a first position (closed position) at which the internal shutter 41 closes the outlet 39, a third position (open position) at which the internal shutter 41 opens the outlet 39, and a second position (operable position) between the first position and the third position. The internal shutter 41 at the second position is in a state in which the internal shutter 41 is movable to the third position while closing the outlet 39. Rotation of the internal shutter 41 about its axis changes the position of the opening 43 between an open position at which the opening 43 faces the outlet 39 and a closed position at which the opening 43 is retracted from the opening position.
The center of rotation of the external shutter 42 coincides with the center of rotation of the internal shutter 41. That is, the external shutter 42 is concentric with the internal shutter 41. As the external shutter 42 is rotated, the outlet 39 is opened and closed.
As illustrated in
When the toner cartridge 30 is installed in the image forming apparatus 100, the drive gear 44 meshes with a drive gear of the body of the image forming apparatus 100. In a state in which the drive gear 44 meshes with the drive gear of the image forming apparatus 100, the drive gear 44, the torque-transmission gear 45, and the drive gear 46 rotate in directions indicated by arrows in
As illustrated in
As illustrated in
As illustrated in
With reference to
As illustrated in
As illustrated in
As illustrated in
As the internal-shutter moving device 57 moves in the direction of arrow D and a tab 57a of the internal-shutter moving device 57 contacts the contact member 55 of the internal shutter 41, the internal shutter 41 is rotated in the direction of arrow C. According to the present illustrative embodiment, the contact member 55 of the internal shutter 41 serves also as an operating member to rotate the internal shutter 41 as the moving member 57 contacts the contact member 55.
With reference to
A sealing member 62 is disposed on the inner surface of the cover 60 to prevent toner from leaking from the outlet 39 (shown in
The retainer 61 is fitted to the outer circumferential surface of the internal shutter 41, thereby holding rotatably the external shutter 42 in the circumferential direction relative to the internal shutter 41. The retainer 61 includes the tab 53 and the interlocking member 54. According to the present illustrative embodiment, the tab 53 includes a projection 63 projecting in the radial direction of the retainer 61. As illustrated in
As illustrated in
The cover 65 includes the opening 43 that can come to a position opposite the outlet 39. A sealing member 67 is disposed on the outer surface of the cover 65 to prevent toner from leaking from the outlet 39. More specifically, the sealing member 67 is disposed between the outer surface of the cover 65 and the inner surface of the container 33 of the toner cartridge 30 (shown in
The projecting portion 66 includes the contact member 55 serving as an operating member. According to the present illustrative embodiment, the operating member 55 includes a projection 68 projecting in the radial direction of the projecting portion 66. The retainer 61 of the external shutter 42 is fitted to the outer circumferential surface of the projecting portion 66.
With reference to
As the toner cartridge 30 is installed in the image forming apparatus 100, as illustrated in
At this time, in conjunction with the rotation of the external shutter 42, the interlocking member 54 of the external shutter 42 presses the contact member 55 of the internal shutter 41, thereby rotating the internal shutter 41 in the same direction as the external shutter 42. With this configuration, the internal shutter 41 is moved to the second position at which the internal shutter 41 is enabled to move to the third position (shown in
After the toner cartridge 30 is installed in the image forming apparatus 100 and the top cover 101 is closed, when the image forming apparatus 100 is turned on the internal-shutter moving device 57 is driven by a driving device. In this case, the internal-shutter moving device 57 is moved to the left as illustrated in
By contrast, in order to close the internal shutter 41, the internal-shutter moving device 57 in the state shown in
As the toner cartridge 30 is removed from the image forming apparatus main body in the state shown in
According to the present illustrative embodiment, when opening the outlet 39, the internal shutter 41 does not move to the second position at which the internal shutter 41 is allowed to open the outlet 39, unless the external shutter 42 is moved to the open position as shown in
Because the internal shutter 41 is prevented from opening while the external shutter 42 is closed, accumulation of toner between the external shutter 42 and the internal shutter 41 is reduced, if not prevented entirely. With this configuration, the toner is prevented from scattering when the external shutter 42 is opened, thus preventing the toner from sticking to the internal surface of the external shutter 42. Handling of the toner cartridge 30 is made easy and contamination of hands of users or technicians is prevented. The toner cartridge 30 is replaced efficiently. Furthermore, faulty operation and degradation of the performance of the devices in the image forming apparatus caused by the scattered toner are prevented, thereby enhancing reliability of the image forming apparatus as a whole.
More specifically, according to the present illustrative embodiment, as illustrated in
According to the present illustrative embodiment, the external shutter 42 is rotated by the rib 56. With this configuration, the external shutter 42 is rotated with a simple configuration and good operability as compared with a known configuration in which a cylindrical shutter is rotated using a rack-and-pinion gear mechanism (for example, JP2009-42567-A). For example, in a case in which the rack-and-pinion gear mechanism is employed, the teeth of the pinion need to mesh with the teeth of the rack smoothly upon installation of the toner cartridge. In order to achieve smooth engagement between the teeth of the pinion and the teeth of the rack, a guide member for guiding the toner cartridge to the image forming apparatus needs to be manufactured with accuracy.
By contrast, according to the present illustrative embodiment, the rib 56 only needs to contact the tab 53. In other words, the position of the rib 56 can be set without high accuracy. Furthermore, the configuration of the guide member for guiding the toner cartridge 30 upon installation of the toner cartridge 30 can be simple, enhancing the operability.
According to the present illustrative embodiment, the internal shutter 41 and the external shutter 42 are controlled by different operating devices, that is, the internal-shutter moving device 57 and the rib 56. With this configuration, in a case in which one of the devices fails, the other device can still operate, thereby preventing both shutters 41 and 42 from getting opened and hence preventing the toner from scattering from the outlet 39.
According to the present illustrative embodiment, the cover 47 covers the tab 53 of the external shutter 42 and the contact member 55 of the internal shutter 41 as illustrated in
According to the present illustrative embodiment, the projection 68 of the internal shutter 41 serves as the contact member that contacts the external shutter 42 and serves also as the operating member that contacts the internal-shutter moving device 57, thereby achieving simplification of the configuration. Alternatively, the contact member and the operating member may be formed of separate parts.
According to the present illustrative embodiment, upon closing the external shutter 42 and the internal shutter 41, the external shutter 42 and the internal shutter 41 are pulled to the closed position by different springs, the tension spring 51 and the tension spring 52. Alternatively, one of the tension springs, for example, the tension spring 51 for pulling the internal shutter 41, may pull both shutters 41 and 42 to the closed position. In other words, when the internal shutter 41 is returned to the first position by the tension spring 51, the contact member 55 of the internal shutter 41 contacts the interlocking member 54 of the external shutter 42 so that the external shutter 42 is moved to the closed position in conjunction with the movement of the internal shutter 41. In this case, the tension spring 52 that pulls the external shutter 42 can be omitted, thereby reducing the number of parts.
According to the present illustrative embodiment, the rib 56 for opening the external shutter 42 is disposed on the middle cover 102 of the image forming apparatus body. Alternatively, as illustrated in
The shutter assembly of the above-described illustrative embodiments is not limited to the toner cartridge 30, but may be applied to a cleaning device for removing residual toner on the image bearing member. For example, as illustrated in
In this example, the cleaning device 70 includes a cleaning member 71, a collecting portion 72, an outlet 73, and a shutter assembly 74. The cleaning member 71 contacts the surface of the photosensitive drum 2 to remove the residual toner therefrom. The collecting portion 72 collects the toner removed by the cleaning member 71. The toner in the collecting portion 72 is discharged from the outlet 73. The shutter assembly 74 opens and closes the outlet 73.
The cleaning device 80 for cleaning the surface of the intermediate transfer belt 8 includes a cleaning member 81, a collecting portion 82, an outlet 83, and a shutter assembly 84. The cleaning member 81 contacts the surface of the intermediate transfer belt 8 to remove the residual toner therefrom. The collecting portion 82 collects the toner removed by the cleaning member 81. The toner in the collecting portion 82 is discharged from the outlet 83. The shutter assembly 84 opens and closes the outlet 83.
The outlet 73 of the cleaning device 70 for the photosensitive drum 2 and the outlet 83 of the cleaning device 80 for the intermediate transfer belt 8 are detachably attachable relative to an inlet 91 of a waste toner container 90. When the outlets 73 and 83 are detached from the inlet 91, or when the inlet 91 is detached from the outlets 73 and 83, the shutter assemblies 74 and 84 close the outlets 73 and 83, respectively.
In a case in which the shutter assemblies 74 and 84 in the cleaning devices 70 and 80 employ a double-shutter assembly, the shutter assemblies 74 and 84 may employ the configuration of the shutter assembly of the illustrative embodiments described above so that the internal shutter is prevented from getting opened while the external shutter is closed. Accordingly, similar to the foregoing illustrative embodiments of the present disclosure, scattering of toner and contamination of the inner surface of the external shutter with the toner such as when only the internal shutter is opened before the external shutter is opened is prevented.
According to an illustrative embodiment of this disclosure, the present invention is employed in the image forming apparatus. The image forming apparatus includes, but is not limited to, an electrophotographic image forming apparatus, a copier, a printer, a facsimile machine, and a multi-functional system.
Furthermore, it is to be understood that elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of this disclosure and appended claims. In addition, the number of constituent elements, locations, shapes and so forth of the constituent elements are not limited to any of the structure for performing the methodology illustrated in the drawings.
Example embodiments being thus described, it will be obvious that the same may be varied in many ways. Such exemplary variations are not to be regarded as a departure from the scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
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2012-180983 | Aug 2012 | JP | national |
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