Developer container, process cartridge and image forming apparatus

A developer container includes: a developer accommodating chamber provided with an opening; a first shutter, including a first portion-to-be-urged, movable between a closing position and an opening position; a second shutter, including a second portion-to-be-urged and being provided outside the first shutter with respect to the opening, movable between a closing position and an opening position; and a partitioning portion provided so as to block between the first and second portions-to-be-urged along moving ranges of the first and second portions-to-be-urged. Movement distances, when the first and second shutters are moved simultaneously from the closing positions, of the first and second shutters from the closing positions to the opening positions are different from each other so that after one of said first and second shutters reaches the opening position, the other shutter is moved to the opening position.

FIELD OF THE INVENTION AND RELATED ART

The present invention relates to a developer container, a process cartridge and an image forming apparatus.

An image forming apparatus (a copying machine, a printer or the like) of a so-called electrophotographic type in which image formation is carried out by developing, with a developer, an electrostatic latent image formed on a photosensitive member by charging and exposure and then by transferring a resultant developer image onto a recording material (medium) needs supply of a fresh (new) developer correspondingly to the consumed developer. In such an image forming apparatus, a constitution in which a developer accommodating portion in a developing device is provided as a developer container, which is a separate member, detachably mountable to an apparatus main assembly of the image forming apparatus and in which the supply of the developer can be easily carried out by replacement of the developer container has been known.

The developer container is provided with an opening for permitting supply of the developer. The opening is connected with a developer supplying opening provided to the apparatus main assembly (developing device), so that the developer is supplied. The developer container is provided with a shutter for opening and closing the opening thereof, and is constituted so as to prevent the developer from leaking out through the opening, e.g., during transportation or the like by blocking the opening with the shutter when the developer container is demounted from the image forming apparatus.

As a structure of the shutter, in order to realize a more completely hermetic sealing of the opening, a double shutter structure in which a single opening is closed with two shutters has been known (Japanese Laid-Open Patent Application (JP-A) 2000-221766).

However, in the double shutter structure as disclosed in JP-A 2000-221766, by erroneous handling of a user, there is a possibility that the two shutters are simultaneously opened in a state in which the developer container is demounted from the image forming apparatus.

SUMMARY OF THE INVENTION

A principal object of the present invention is to provide a developer container, including two shutters, capable of suppressing an open state of an opening thereof by erroneously handling thereof by a user.

According to an aspect of the present invention, there is provided a developer container comprising: a developer accommodating chamber, provided with an opening, for accommodating a developer; a first shutter, including a first portion-to-be-urged, movable between a closing position where the opening is closed and an opening position where the opening is opened by urging the first portion-to-be-urged; a second shutter, including a second portion-to-be-urged and being provided outside the first shutter with respect to the opening, movable between a closing position where the opening is closed and an opening position where the opening is opened by urging the second portion-to-be-urged; and a partitioning portion provided so as to block between the first and second portions-to-be-urged along moving ranges of the first and second portions-to-be-urged, wherein movement distances, when the first and second shutters are moved simultaneously from the closing positions, of the first and second shutters from the closing positions to the opening positions are different from each other so that after one of the first and second shutters reaches the opening position, the other shutter is moved to the opening position.

According to another aspect of the present invention, there is provided a process cartridge, detachably mountable to an apparatus main assembly of an image forming apparatus, for performing an image forming process for forming an image on a recording material by a developer, wherein the above-mentioned developer container is detachably mounted to the process cartridge.

According to further aspect of the present invention, there is provided an image forming apparatus for forming the image on the recording material by the developer, wherein the above-mentioned developer container is detachably mounted to the apparatus main assembly or the process cartridge detachably mountable to the apparatus main assembly.

DESCRIPTION OF THE EMBODIMENTS

Embodiments for carrying out the present invention will be specifically described with reference to the drawings. Dimensions, materials, shapes and relative arrangement of constituent elements described in the following embodiment should be appropriately be changed depending on structures and various conditions of devices (apparatuses) to which the present invention is applied. Accordingly, the scope of the present invention is not intended to be limited to the following embodiments.

Here, an image forming apparatus (electrophotographic image forming apparatus) forms an image on a recording material with a developer (toner) by using an electrophotographic image forming process. The image forming apparatus includes, e.g., an electrophotographic copying machine, an electrophotographic printer (such as LED printer or laser beam printer), an electrophotographic facsimile machine, an electrophotographic word processor, and a multi-function machine (such as multi-function printer) having functions of these machines. Further, the recording material is an object on which an image is to be formed, and is, e.g., a recording sheet, an OHP sheet and so on.

Further, a process cartridge is a cartridge prepared by integrally assembling an electrophotographic photosensitive drum and, as a process means actable on the photosensitive drum, at least one of a charging device, a developing means and a cleaning means into a unit. The process cartridge is detachably mountable to an image forming apparatus main assembly. In the following, the apparatus main assembly refers to an apparatus structural portion obtained by removing at least the process cartridge and a developer container from the structure of the apparatus main assembly.

With reference toFIG. 2, an image forming apparatus according to Embodiment 1 of the present invention will be described.FIG. 2is a schematic sectional view showing a structure of the image forming apparatus in this embodiment. In this embodiment, as the image forming apparatus, the case where the present invention is applied to a monochromatic laser beam printer as a monochromatic image forming apparatus will be described. Incidentally, the present invention is also applicable to a four-color based full-color laser beam printer as an image forming apparatus for a plurality of colors.

An image forming apparatus1shown inFIG. 2includes, in an apparatus main assembly2, an image forming portion3, a sheet-feeding device4, a fixing device13and a paper-discharging device15. The image forming portion3forms an image, by an electrophotographic image forming process, on a sheet S as a recording material (medium) fed by the sheet-feeding device4. The fixing device13fixes the image, formed at the image forming portion3, on the sheet S, and then the paper-discharging device15discharges the sheet S, on which the image is fixed, onto a paper discharge tray17.

The image forming portion3includes a photosensitive drum5as an image bearing member, a developing device6, and a developer container (developer accommodating container)7for supplying a developer to the developing device6via a connecting portion20, and a laser scanner19for exposing the photosensitive drum5to light. During image formation, the photosensitive drum5is exposed to light by the laser scanner19to form a latent image on the surface of the photosensitive drum5, and thereafter this latent image is developed, so that an image with a developer (i.e., a developer image) is formed on the surface of the photosensitive drum5.

The sheet-feeding device4includes a paper-feeding cassette8provided detachably mountable to the apparatus main assembly2and a feeding roller9, provided over the paper-feeding cassette8, for feeding to sheet S accommodated in the paper-feeding cassette8.

The sheet-feeding device feeds the sheet S, accommodated in the paper-feeding cassette8, by the feeding roller9and thereafter conveys the sheet S to a registration roller pair11by a conveying roller pair10in parallel to the image forming operation with the developer at the above-described image forming portion3. Incidentally, after being conveyed to the registration roller pair11as described above, the sheet S is conveyed by the registration roller pair11at predetermined timing to a transfer portion formed by the photosensitive drum5and the transfer roller12.

Onto the sheet S conveyed to the transfer portion, the image formed on the surface of the photosensitive drum5is transferred at the transfer portion. Thereafter, the sheet S is conveyed into the fixing device13, and is heated and pressed in the fixing device13, so that the image is fixed on the sheet S. The sheet S is, after the image is fixed thereon, discharged onto the paper discharge tray17, provided at an upper surface of the apparatus main assembly2, via a paper-discharging path by a paper-discharging roller pair16provided in the paper(sheet)-discharging device15.

With reference toFIGS. 1,3and4, the developer container7according to Embodiment 1 will be described. InFIG. 1, (a) and (b) are schematic views showing the structure of the developer container7in this embodiment and showing a closed state of shutters, in which (a) is a perspective view of showing an opening and a periphery thereof, and (b) is a cross-sectional view, of the opening and the periphery thereof, taken along a line perpendicular to a longitudinal direction (arrow Z direction of (a) (Z-Z cross-sectional view of (a)).

InFIG. 1, (a) and (b) are schematic views showing the structure of the developer container7in this embodiment and showing an open state of shutters connected with the developing device6, in which (a) is a perspective view of showing an opening and a periphery thereof, and (b) is a cross-sectional view, of the opening and the periphery thereof, taken along a line perpendicular to a longitudinal direction (arrow Z direction of (a) (Z-Z cross-sectional view of (a)).

InFIG. 1, (a) and (b) are schematic views, showing the structure of the developer container7in this embodiment, for illustrating a relationship between movement amounts of two shutters and a change in an open and closed state, in which (a) is a perspective view of showing an opening and a periphery thereof, and (b) is a cross-sectional view, of the opening and the periphery thereof, taken along a line perpendicular to a longitudinal direction (arrow Z direction of (a) (Z-Z cross-sectional view of (a)).

The developer container7in this embodiment is provided with openings30ato30cand a developer accommodating chamber30in which the developer is accommodated. The openings30ato30cfor the developer accommodating chamber30are constituted so as to be openable and closable by shutters32aand33aas first and second shutters, respectively. A fixing rib36as a partitioning portion is formed on an outer surface of the developer accommodating chamber30so as to block between a moving range of each of the shutters32aand33a.

The openings30ato30cconsist of a first opening30aprovided closest to an inside of the developer accommodating chamber30, a second opening30bprovided remotest from the inside of the developer accommodating chamber30, and a third opening30cprovided between the first and second openings30aand30b. The opening30cis formed as a through hole provided in a plate-like portion31cprovided with a gap in parallel to an outer surface of a wall portion31a, as a wall portion of the developer accommodating chamber30, where the opening30ais provided. The opening30bis formed as a through hole provided in a plate-like portion31bprovided with a gap in parallel to the plate-like portion31cin an outside of the plate-like portion31c.

The respective openings30ato30care provided at positions where they overlap with each other along an opening direction (arrow X direction of (b) ofFIG. 1). In a state in which all the openings30ato30bare not closed by any of the two shutters32aand33a, a state in which the inside of the developer accommodating chamber30opens to the outside of the developer accommodating chamber30is created.

The shutters32aand33aare a plate-like member, and are assembled at the gap between the wall portion31aprovided with the opening30aand the plate-like portion31cprovided with the opening30c, and between the plate-like portion31cprovided with the opening30cand the plate-like portion31bprovided with the opening30b, respectively. That is, the shutter32ais disposed between the wall portion31aand the plate-like portion31c, and the shutter33ais disposed between the plate-like portions31cand31b.

Levers32band33bare provided, as operating portions (portions-to-be-urged) for sliding and moving the shutters32aand33a, respectively, in the above-described gaps, integrally with each of the shutters32aand33aso as to be projected from the outer surface of the developer container7. By urging (pressing) the levers32band33b, the shutters32aand33aare constituted so as to be slidable and movable independently along the gaps between the surfaces of the wall portion31aand the plate-like portion31cand between the surfaces of the plate-like portions31cand31b, respectively (in arrow E direction ofFIG. 1).

Feeding openings32cand33care through holes provided in the shutters32aand33a, respectively, and are provided so as to be capable of overlapping with the openings30ato30calong the opening direction (arrow X direction of (b) ofFIG. 1) of the openings30ato30c. When the shutters32aand33aare located at positions where both the feeding openings32cand33care placed in an overlapping state with the openings30ato30c, the inside of the developer accommodating chamber30opens to the outside of the developer accommodating chamber30.

The shutters32aand33aare urged in a direction opposite to the arrow E direction by unshown springs, and in a free state in which no external force is applied, are constituted so as to maintain a closed state in which the openings30ato30care completely closed as shown inFIG. 1. When each of the shutters32aand33ais slid and moved to the closing position by applying an external force to an associated one of the levers32band33b, as shown inFIG. 3, the openings30ato30care placed in an open state. As a result, the developer container7is capable of feeding the developer, accommodated in the developer accommodating chamber30, in an outward direction (arrow X direction).

The fixing rib36is provided between the moving ranges of the levers32band33bof the shutters32aand33a, along a movement direction (arrow E direction ofFIG. 1) of the levers32band33b. The fixing rib36is constituted so that a height thereof with respect to a direction perpendicular to the movement directions of the levers32band33b(i.e., with respect to arrow G direction of (b) ofFIG. 1perpendicular to both the arrow E direction and the arrow E direction of (a) ofFIG. 1) is higher than heights of the levers32band33b. Further, the fixing rib36is, as shown inFIG. 1, provided so that the fixing rib36is broader than each of widths of the levers32band33band blocks between the levers32band33bin a range of a positional relationship such that the shutters32aand33aare located at least at the closing positions within the moving ranges thereof.

As shown inFIG. 3, the developer container7is mounted at a predetermined position of the apparatus main assembly2(developing device6), and at the same time the shutters32aand33aare opened, whereby the openings30ato30care placed in a state in which the openings30aand30ccommunicate with a developer supplying opening60of the developing device6. As a result, the developer container7is capable of supplying (feeding) the developer into the developing device6.

<Opening and Closing of Shutters>

With reference toFIGS. 5 and 6, a shutter operating portion for opening and closing the shutters32aand33aof the developer container7in the apparatus main assembly2. InFIG. 5, (a) and (b) are schematic views showing a structure of the shutter operating portion in this embodiment, in which (a) is a side view in a state before an openable door18is closed after the developer container7is mounted in the apparatus main assembly2(developing device6), and (b) is a perspective view in the state. InFIG. 6, (a) and (b) are schematic views showing the structure of the shutter operating portion in this embodiment, in which (a) is a side view in a state after the openable door18is opened, and (b) is a perspective view in the state.

The developer container7is constituted so as to be detachably mountable to the apparatus main assembly2(developing device6) by opening the openable door18as a cover member provided to the apparatus main assembly2. The openable door18is provided with projected portions18aand18bas the shutter operating portion (urging portion).

With respect to the developer container7, as shown inFIG. 5, in a state in which the openable door18is open, the shutters32aand33aare located at the closing positions, so that openings30ato30care closed. The openable door18is, when being closed by an operation of a user, rotated relative to the apparatus main assembly2while the projected portions18aand18bpush the levers32band33bin an arrow E direction (which is the same direction as the arrow E direction in (a) ofFIG. 1and the like), thus moving the shutters32aand33afrom opening positions to the closing positions (FIG. 6). As a result, the openings30ato30care opened, thus being placed in a communication state with the developer supplying opening60of the developing device6.

In this way, the developer container7is constituted so that the state in which the shutters32aand33aare closed until the openable door18is closed. As a result, leakage of the developer during an exchanging (replacing) operation of the developer container7is prevented.

The projected portions18aand18bare constituted so that projected amounts (heights) thereof are different depending on movement amounts of the levers32band33bpushed by the projected portions18aand18b, respectively (i.e., movement amounts of the shutters32aand32bfrom the closing positions to the opening positions).

<Excellent Points of this Embodiment>

As described above, the developer container7is provided with the fixing rib36which is higher than the levers32band33band which is wider than the levers32band33bwith respect to the movement direction, so that the user does not readily touch the levers32band33bat the same time. That is, e.g., in a state such that the user holds the developer container7, a constitution in which it is difficult to handle the two shutters simultaneously is employed. As a result, it is possible to suppress erroneous opening of the shutters32aand33aby the user.

Further, a constitution in which the opening is not opened even when only one of the levers is handled is employed. Further, a constitution in which even when the two shutters are handled simultaneously, the two shutters are different from each other in movement distance from the closing position to the opening position and are not located at their opening positions at the same time, and therefore are not opened immediately is employed. Accordingly, even if the user touches both the levers32band33b, there is a low possibility that the shutters32aand33aare operated to be moved to their positions.

Further, as shown inFIG. 4, in the case where the positions of the levers are aligned with each other along a direction perpendicular to the movement directions, the shutters are not placed in a state in which the opening is opened. That is, the positions of the levers in the open state are different from each other, and therefore in the case where the user intends to open the shutters by handling the levers, the user is required to independently adjust the position of each of the levers. Accordingly, unless the user intentionally handles the levers, a plurality that both the shutters are moved to the opening positions simultaneously is low.

As described above, according to this embodiment, with respect to the developer container7provided with two shutters, it is possible to suppress the opening of the shutters by erroneous handling of the levers by the user, so that a possibility of leakage of the developer from the developer container7can be considerably alleviated.

In this embodiment, the feeding openings32aand33cof the shutters32aand33aare provided in the form of the through holes, but are not limited thereto. If the feeding openings are in the form such that the feeding openings are capable of opening the portion, various constitutions can be employed. For example, in place of the through holes, the form such as cut-away portions may also be employed, and a constitution in which one of the shutters is provided with the through hole and the other shutter is provided with the cut-away portion may also be employed.

With reference toFIGS. 7 to 9, the developer container7according to Embodiment 2 will be described. In this embodiment, a point different from Embodiment 1 will be principally described. Constituent elements similar to those in Embodiment 1 are represented by the same reference numerals or symbols, and will be appropriately omitted from description. The matters which are not described in this embodiment are the same as those in Embodiment 1.

InFIG. 7, (a) and (b) are schematic views showing the structure of the developer container7in this embodiment and showing a closed state of shutters, in which (a) is a perspective view of showing an opening and a periphery thereof, and (b) is a cross-sectional view, of the opening and the periphery thereof, taken along a line perpendicular to a longitudinal direction (arrow Z direction of (a) (Z-Z cross-sectional view of (a)).

InFIG. 8, (a) and (b) are schematic views showing the structure of the developer container7in this embodiment and showing an open state of shutters connected with the developing device6, in which (a) is a perspective view of showing an opening and a periphery thereof, and (b) is a cross-sectional view, of the opening and the periphery thereof, taken along a line perpendicular to a longitudinal direction (arrow Z direction of (a) (Z-Z cross-sectional view of (a)).

The developer container7in this embodiment has a constitution in which the movement directions of the shutters during opening and closing are opposite to those for the developer container7in Embodiment 1.

In this embodiment, with respect to the developer container7, similarly as in Embodiment 1, the openings30ato30cfor the developer accommodating chamber30are opened and closed by shutters82aand83aas first and second shutters, respectively. The sheets82aand83aare, similarly as in the case of the shutters32aand33ain Embodiment 1, integrally provided with levers82band83band feeding openings82cand83cfor feeding the developer. A fixing rib86as a partitioning portion is formed on an outer surface of the developer accommodating chamber30so as to block between a moving range of each of the shutters82aand83a.

The shutters82aand83aare urged in a direction opposite to an arrow F direction by unshown springs, and in a free state in which no external force is applied, are constituted so as to maintain a closed state in which the openings30ato30care completely closed as shown inFIG. 7. When each of the shutters82aand83ais slid and moved to the closing position by applying an external force to an associated one of the levers82band83b, as shown inFIG. 8, the openings30ato30care placed in an open state. As a result, the developer container7is capable of feeding the developer, accommodated in the developer accommodating chamber30, in an outward direction (arrow X direction).

As shown in (b) ofFIG. 7, the fixing rib86has a shape such that the fixing rib86is projected more than (i.e., is larger than) the s82band83bwith respect to both the shutter opening and closing direction (arrow F direction) and an opening direction (arrow G direction) in a state in which the shutters82aand83aare located at their closing positions.

<Opening and Closing of Shutters>

FIG. 9is a schematic perspective view showing a structure of a shutter operating portion in this embodiment in a perpendicular to in which the developer container7is mounted in the apparatus main assembly2(developing device6) and then the openable door18is closed. In this embodiment, the developing device6is provided with a projected portion51as an urging portion. Further, an unshown frame of the apparatus main assembly2is provided, as an urging portion, with a lever91rotatable about a rotation shaft90.

First, when the developer container7is mounted to the developing device6, the lever83bis pushed in the arrow F direction by the projected portion51, so that the state of the shutter83ais changed from a state in which the shutter83ablocks between the openings30aand30b.

Then, when the openable door18is closed, the lever91is urged in an arrow K direction by a projected portion18C provided on the openable door18. The lever91is rotated about the rotation shaft90to urge the lever82bin an arrow H direction. The lever82bis pushed, whereby the shutter82ais moved in the arrow F direction, and thus the state of the shutter82ais changed from the state in which the shutter82ablocks between the openings30cand30bto an open state. As a result, the openings30ato30care placed in an open state.

<Excellent Points of this Embodiment>

Also in this embodiment, similarly as in Embodiment 1, with respect to the developer container7provided with two shutters, it is possible to suppress the opening of the shutters by erroneous handling of the levers by the user, so that a possibility of leakage of the developer from the developer container7can be considerably alleviated.

Incidentally, according to this embodiment, in addition to the functional effect similar to that in Embodiment 1, it is possible to reduce a force required for the opening and closing operation of the openable door18. That is, in Embodiment 1, there are the two levers32band33bmoved by the closing operation of the openable door18, whereas in this embodiment, only one lever82bis moved. Further, as shown inFIG. 9, by adjusting lengths LD and LE from a rotation center (rotation shaft90) of the lever91, it is possible to adjust an operating force of the openable door18and an operation amount of the operating lever91.

Incidentally, the above-described embodiments can be applied by combining their constitutions with each other.

According to the present invention, in the developer container provided with the two shutters, it is possible to suppress the opening of the opening due to erroneous handling by the user.

This application claims priority from Japanese Patent Application No. 131887/2013 filed Jun. 24, 2013, which is hereby incorporated by reference.