Toner collection unit and image forming apparatus incorporating same

A toner collection unit, which can be included in an image forming apparatus, includes a collected toner container having an opening and storing collected toner, a flexible seal sealing the opening of the collected toner container, having a shape of a recess in an initial condition before toner is collected in the container, and being flexible to change the shape to inflate outwardly due to a pressing force exerted from the toner stored in the container, a moving unit disposed outside the flexible seal and movable both in a positive direction to approach the opening of the container and in an opposite direction to move away from the opening when contacting the flexible seal inflating outwardly, a detector detecting movement of the moving unit, and a regulator regulating the moving unit from coming into the recess of the flexible seal in the initial condition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is based on and claims priority pursuant to 35 U.S.C. §119 to Japanese Patent Application No. 2012-259979, filed on Nov. 28, 2012 in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.

BACKGROUND

1. Technical Field

Embodiments of the present invention relate to a toner collection unit that stores toner such as waste toner collected from units and components provided in an image forming apparatus, and an image forming apparatus including the toner collection unit therein.

2. Related Art

In electrophotographic image forming apparatuses, toner is transferred from a photoconductor onto a transfer belt and from the transfer belt onto a recording medium. In performing these toner transfer operations, it is difficult to achieve a perfect or 100% transfer rate, and therefore residual toner remains on the photoconductor and the transfer belt after the toner transfer operations. The residual toner is collected by a cleaner having a suitable configuration for operations in each electrophotographic image forming apparatus and stored as waste toner in a toner collection unit provided in the image forming apparatus. As the amount of waste toner stored in the toner collection unit approaches a full state, a message is issued to report the status of the toner collection unit. In response to the report, a user or a service engineer replaces the toner collection unit to a new unit or disposes the toner collection unit.

As an example of detection that an amount of waste toner of a toner collection unit approaches the toner full state, Japanese Patent Application Publication No. JP 2009-199005-A discloses a configuration in which a flexible seal is provided to a waste toner collection unit in a downwardly warped manner, as illustrated in FIGS. 9 and 10 thereof. When the waste toner collection unit is filled with waste toner, the flexible seal is warped upwardly. This deformation of the flexible seal pushes up a moving member, so that a photointerrupter detects movement of the moving member.

However, even though the flexible seal is deformed due to accumulation of waste toner in the waste toner collection unit, the shape of the flexible seal does not change uniformly over the whole flexible seal. Actually, it is likely that the change of shape of the flexible seal occurs irregularly and unevenly and the flexible seal has locally deformed areas on a surface thereof. Therefore, the locally deformed areas of the flexible seal may be caught at an edge of the moving member or be pried at a support portion of the moving member. Such unevenly changed flexible seal can apply a load to the moving member when the moving member moves. Consequently, the photointerrupter causes a delay in detecting the full state in the waste toner collection unit, which is likely to cause leakage of waste toner.

As disclosed in JP 2009-199005-A, the moving member is disposed in a recessed space of the flexible seal in an initial condition that is a condition before waste toner is collected to the waste toner collection unit.FIG. 1is an example drawing that illustrates a position of a moving member in the initial condition. As illustrated inFIG. 1, when a flexible seal330is warped or bulged out, the flexible seal330easily comes into a gap between the moving member300and an edge of an opening320of a waste toner collection unit310. Consequently, it is likely that the flexible member330twines around the moving member300. In this case, a load is applied on the moving member300when the moving member300moves. Therefore, the above-described inconveniences become obvious.

SUMMARY

The present invention provides a toner collection unit including a collected toner container having an opening and storing collected toner, a flexible seal configured to seal the opening of the collected toner container, having a cross-sectional recess in an initial condition before the toner is collected in the collected toner container, and being flexible to change the shape to inflate outwardly due to a pressing force exerted from the toner stored in the collected toner container, a moving unit disposed outside the flexible seal and movable both in a positive direction to approach the opening of the collected toner container and in an opposite direction to move away from the opening of the collected toner container, and configured to rotate in the opposite direction when contacting the flexible seal inflating outwardly, a detector configured to detect movement of the moving unit, and a regulator configured to regulate the moving unit from coming into the recess of the flexible seal in the initial condition.

Further, the present invention provides an image forming apparatus including an image forming unit configured to form an image, and the above-described toner collection unit.

Further, the present invention provides an image forming apparatus including a collected toner container having an opening, a flexible seal to seal the opening and to include a recessed portion being inflatable outwardly, a contact plate including an extended portion that extends out of the recessed portion, and a detector to detect movement of the contact plate. The extended portion contacts with an adjacent area of the opening when the recessed portion recesses, and the contact plate moves outwardly when the recessed portion inflates outwardly.

Further, the present invention provides an image forming apparatus including a collected toner container having an opening, a flexible seal to seal the opening and to include a recessed portion being inflatable outwardly, a contact plate to contact with the recessed portion and to move by inflation of the recessed portion, and a detector to detect movement of the contact plate. A width of the contact plate is greater than a width of the opening.

DETAILED DESCRIPTION

Descriptions are given, with reference to the accompanying drawings, of examples, exemplary embodiments, modification of exemplary embodiments, etc., of an image forming apparatus according to exemplary embodiments of the present invention. Elements having the same functions and shapes are denoted by the same reference numerals throughout the specification and redundant descriptions are omitted. Elements that do not demand descriptions may be omitted from the drawings as a matter of convenience. Reference numerals of elements extracted from the patent publications are in parentheses so as to be distinguished from those of exemplary embodiments of the present invention.

The present invention is applicable to any image forming apparatus, and is implemented in the most effective manner in an electrophotographic image forming apparatus.

In describing preferred embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of the present invention is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes any and all technical equivalents that have the same function, operate in a similar manner, and achieve a similar result.

A description is given of a configuration and functions of an image forming apparatus100according to an embodiment of the present invention, with reference toFIG. 2.

The image forming apparatus100may be a copier, a facsimile machine, a printer, a multifunction peripheral or a multifunction printer (MFP) having at least one of copying, printing, scanning, facsimile, and plotter functions, or the like. According to the present embodiment, the image forming apparatus100is an electrophotographic color printer that forms color and monochrome toner images on recording media by electrophotography.

As illustrated inFIG. 2, the image forming apparatus100includes units and components for image forming in a body101. The body101contains four image forming units1Y,1M,1C, and1K at a center part thereof. The image forming units1Y,1M,1C, and1K form yellow (Y), magenta (M), cyan (C), and black (K) toner images, respectively, which correspond to respective color separation elements of color images. Except for the colors of toners, the image forming units1Y,1M,1C, and1K have configurations identical to each other.

Hereinafter, the units and components included in the body101of the image forming apparatus100are often referred to in a singular unit without suffix indicating toner colors. For example, the image forming units1Y,1M,1C, and1K may be referred to as “the image forming unit1”.

The photoconductor2functions as an image carrier to carry an electrostatic image on a surface thereof.

The charging roller3functions as a charger to uniformly charge the surface of the photoconductor2.

The development unit4supplies toner to the electrostatic latent image formed on the charged surface of the photoconductor2and develops the electrostatic latent image into a visible toner image.

The photoconductor cleaning unit5cleans the surface of the photoconductor1.

Further, the image forming unit1is formed in a process cartridge that is detachably attachable to the body101of the image forming apparatus100. The process cartridge integrally includes the photoconductor2, the charging roller3, the development unit4, and the photoconductor cleaning unit5.

The development unit4includes a toner hopper4ato contain toner therein and a development roller4b.The toner contained in the toner hopper4ais supplied to a surface of the photoconductor2along with rotation of the development roller4b.Polymerized toner having roundness in a range of from 0.96 to 0.98 is preferably used as toner of each color contained in the toner hopper4a.

The photoconductor cleaning unit5cleans the surface of the photoconductor2. The photoconductor cleaning unit5includes a cleaning blade5athat contacts in a counter direction with respect to a rotational direction of the photoconductor2

As illustrated inFIG. 2, the body101of the image forming apparatus100further includes an exposure unit6disposed above the image forming units1Y,1M,1C, and1K.

The exposure unit6included in the image forming apparatus100according to the present embodiment includes a light source, a polygon mirror, fθ (f-theta) lens, reflection mirrors, and so forth to function as an electrostatic latent image forming unit. The exposure unit6emits laser light to the surface of the photoconductor2based on image data so as to expose the charged surface of the photoconductor2to form an electrostatic latent image for a given single color toner image. Alternatively, the exposure unit6can include an LED (light emitting diode) array or LED arrays.

As illustrated inFIG. 2, the body101of the image forming apparatus100further includes a transfer unit7disposed below the image forming units1Y,1M,1C, and1K.

The transfer unit7transfers the toner image onto a paper P functioning as a recording medium. The transfer unit7includes an intermediate transfer belt8functioning as an endless transfer belt. The intermediate transfer belt8is spanned around a drive roller9, a driven roller10, and primary transfer rollers11Y,11M,11C, and11K in a loop. As the drive roller9rotates counterclockwise inFIG. 2, the intermediate transfer belt8rotates in a direction indicated by arrow A inFIG. 2.

The primary transfer roller11(i.e., the primary transfer rollers11Y,11M,11C, and11K) is disposed facing the photoconductor2with the intermediate transfer belt8interposed therebetween. Specifically, the primary transfer roller11presses against an inner circumferential surface of the intermediate transfer belt8, thereby forming a primary transfer nip area where the pressed area of the intermediate transfer belt8and the photoconductor2contact each other. The primary transfer roller11is connected to a power supply from which a given direct current (DC) voltage and/or a given alternating current (AC) voltage are applied to the primary transfer roller11. It is to be noted that the primary transfer roller11functioning as a primary transfer member in the present embodiment is a metallic roller. However, a conductive blade or a conductive sponge roller can be used instead of a metallic roller.

As illustrated inFIG. 2, the body101of the image forming apparatus100further includes a secondary transfer roller12disposed facing the drive roller9.

The secondary transfer roller12functions as a secondary transfer member to press against the outer circumferential surface of the intermediate transfer belt8. Where the pressed area of the intermediate transfer belt8and the secondary transfer roller12contact each other forms a secondary transfer nip area. Similar to the primary transfer roller11, the secondary transfer roller12is connected to a power supply from which a given direct current (DC) voltage and/or a given alternating current (AC) voltage are applied to the secondary transfer roller12. The secondary transfer roller12includes a metallic core covered by an elastic body of conductive material. As an example of the secondary transfer roller12, a conductive roller, an electronically conductive roller or the like can be employed.

Further, as illustrated inFIG. 2, the body101of the image forming apparatus100includes a belt cleaning device13disposed on an outer circumferential surface of the intermediate transfer belt8at a position upstream from the image forming units1Y,1M,1C, and1K (on a loosened side of the intermediate transfer belt8) in the direction A. The belt cleaning device13includes a cleaning blade13athat contacts in a counter direction with respect to a moving direction of the intermediate transfer belt8.

As illustrated inFIG. 2, the body101of the image forming apparatus100further includes a duct26and a toner collection unit14that includes a collected toner container30. The duct26is disposed below the transfer unit7and the toner collection unit14is disposed below the duct26.

The duct26functions as a toner conveying member and is connected to an inlet27provided to the collected toner container30.

Toner or waste toner collected by the photoconductor cleaning device5and the belt cleaning device13is conveyed via the duct26and the inlet27and stored in the collected toner container30of the toner collection unit14.

A sheet tray15and a feed roller16are disposed at a lower part of the body101of the image forming apparatus100inFIG. 2.

The sheet tray15accommodates a stack of sheets including a sheet S functioning as a recording medium.

The feed roller16feeds the sheet S from the sheet tray15.

It is to be noted that the sheet S is not limited to indicate paper material but also includes thick paper, postcard, envelope, regular paper, coated paper, art paper, tracing paper and the like. Further, as a recording medium, a plastic material such as OHP sheet, OHP film and the like can be used.

The body101of the image forming apparatus100inFIG. 2includes a sheet discharging roller pair17and a sheet discharging tray18.

The sheet discharging roller pair17is disposed at an upper part of the body101to discharge the sheet S to an outside of the body101.

The sheet discharging tray18is provided on top of an upper surface of the body101to stock the sheet S discharged outside by the sheet discharging roller pair17.

A sheet pathway R is defined by the rollers and units disposed in the body101of the image forming apparatus100to convey the sheet S from the sheet tray15to the sheet discharging tray18via the secondary transfer nip area.

A registration roller pair19is disposed upstream from the secondary transfer roller12in a sheet conveying direction in the sheet pathway R. The registration roller pair19functions as a timing roller pair to convey the sheet S to the second transfer nip area by adjusting a timing to convey the sheet S with movement of the toner image formed on the surface of the intermediate transfer belt8.

A fixing unit20is disposed downstream from the secondary transfer roller12in the sheet conveying direction. The fixing unit20fixes an unfixed toner image transferred onto the sheet S to the sheet S. The fixing unit20includes a fixing roller24that includes a heater and a pressure roller25that is pressed by the fixing roller24. Where the fixing roller24and the pressure roller25contact each other forms a fixing nip area.

Next, a description is given of basic image forming operations of the image forming apparatus100according to an embodiment with reference toFIG. 2.

As shown inFIG. 2, a non-illustrated controller provided to the image forming apparatus100issues a signal to a non-illustrated drive unit drives to rotate the photoconductor2of the image forming unit1clockwise inFIG. 2. As the photoconductor2rotates, the charging roller3uniformly charges the surface of the photoconductor2to a given polarity. The exposure unit6emits laser light based on image data transmitted from a non-illustrated image reading device and/or the controller to irradiate the charged surface of the photoconductor2. With this action, an electrostatic latent image is formed on the surface of the photoconductor2. The image data exposed to the photoconductors2Y,2M,2C, and2K is single color image data produced by separating a full-color image into respective color data of yellow, magenta, cyan, and black. The development unit4develops the thus-created electrostatic image on the surface of the photoconductor2into a visible toner image by supplying toner.

As the image forming operation starts, the controller starts the intermediate transfer belt8to rotate in the direction A inFIG. 2. Further, a voltage controlled to have a constant voltage or a constant current is applied to the primary transfer roller11so as to be charged to a polarity opposite to a toner charge polarity. With this action, a transfer magnetic field is generated in the primary transfer nip area.

Thereafter, as the photoconductors2Y,2M,2C, and2K rotate, the respective toner images formed on the photoconductors2Y,2M,2C, and2K are conveyed toward the respective primary transfer nip areas. When the toner images reach the respective primary transfer nip areas, the respective toner images formed on the photoconductors2Y,2M,2C, and2K are sequentially overlaid each other and transferred onto the intermediate transfer belt8due to action of the transfer magnetic fields generated at the respective primary transfer nip areas. Accordingly, a full-color toner image is formed on the surface of the intermediate transfer belt8. Residual toner that remains on the surface of the photoconductor2after transfer of the toner image onto the intermediate transfer belt8is removed by the cleaning blade5aof the photoconductor cleaning unit5to clean the surface of the photoconductor2. The residual toner removed from the surface of the photoconductor2is conveyed to the collected toner container30of the toner collection unit14via the duct26.

Further, a non-illustrated electric discharging unit removes residual charge on the surface of the photoconductor2. Consequently, the charge of the surface of the photoconductor2is initialized to be ready for a subsequent image forming operation.

Further, the controller also causes the feed roller16to rotate to feed the sheet S from the sheet tray15to the sheet pathway R. Conveyance of the sheet S fed in the sheet pathway R is controlled by the registration roller pair19before the sheet S reaches the secondary transfer nip area. At this time, the secondary transfer roller12is applied with a transfer voltage that has the polarity opposite to the toner charge polarity on the toner image formed on the intermediate transfer belt8. With this application of the transfer voltage to the secondary transfer roller12, a transfer magnetic field is formed in the secondary transfer nip area.

Thereafter, as the intermediate transfer belt8rotates, the toner image formed on the intermediate transfer belt8approaches the secondary transfer nip area. When the toner image reaches the secondary transfer nip area, the transfer magnetic field generated in the secondary transfer nip area causes the toner image on the intermediate transfer belt8to be transferred onto the sheet S.

Residual toner that remains on the surface of the intermediate transfer belt8after transfer of the toner image onto the sheet S is removed by the cleaning blade13aof the belt cleaning unit13to clean the surface of the intermediate transfer belt8. Similar to the residual toner removed from the surface of the photoconductor2, the residual toner removed from the surface of the intermediate transfer belt8is conveyed to the collected toner container30of the toner collection unit14via the duct26.

Thereafter, the sheet S is conveyed to the fixing unit20. In the fixing unit20, as the sheet S passes through the fixing nip area formed between the fixing roller24and the pressure roller25, the toner image is fixed to the sheet S. Then, the sheet S is discharged by the sheet discharging roller pair17and is stack on the sheet discharging tray18.

The above-described basic image forming operations are performed by the image forming apparatus100for forming a full-color image on the sheet S. However, a monochrome image can be formed by using one of the image forming units1Y,1M,1C, and1K. Alternatively, a two-color image or a three-color image can be formed by using two or three of the image forming units1Y,1M,1C, and1K.

A description is given of a configuration of the toner collection unit14with reference toFIGS. 3 and 4.

FIG. 3is a perspective view illustrating a structure of one end side of the toner collection unit14, andFIG. 4is a front view of the toner collection unit14viewed from the one end side of the toner collection unit14illustrated inFIG. 3.

It is to be noted that this “one end side” indicates a downstream side of a conveying member31in a toner conveying direction indicated by arrow “α” inFIG. 2.

As illustrated inFIGS. 3 and 4, the toner collection unit14basically includes the collected toner container30, the conveying member31, and a toner full detection mechanism32.

The toner full detection mechanism32is disposed at the one end side of the collected toner container30of the toner collection unit14.

The collected toner container30is detachably attached to the body101of the image forming apparatus100in view of operability of disposal of waste toner when the waste toner stored in the collected toner container30reaches a toner full state.

The collected toner container30is a resin box that contains the waste toner collected by the photoconductor cleaning device5and the belt cleaning device13. To increase charging efficiency of waste toner in the collected toner container30, it is preferable that the collected toner container30has a sufficient height to accumulate the waste toner in a vertical direction thereof. However, the inside of the body101of the image forming apparatus100is a limited space, and therefore it is difficult to include the collected toner container30having the above-described size and structure to accumulate the waste toner vertically. To address this inconvenience, the collected toner container30employed in the present embodiment has a shape of cuboid or rectangular solid with a small length of each vertical lines. As illustrated inFIG. 2, the collected toner container30is arranged inside the body101of the image forming apparatus100with a longitudinal line thereof in a horizontal direction.

With reference toFIG. 5, a description is given of a configuration of the one end side of the toner collection unit14.

FIG. 5is a cross-sectional view of the one end side of the toner collection unit14along a line I-I ofFIG. 4.

As illustrated inFIG. 5, the conveying member31is disposed along the longitudinal direction of the collected toner container30above the collected toner container30. The conveying member31is rotatably supported by the collected toner container30at both ends in the longitudinal direction thereof and is driven to rotate by a drive source disposed in the body101of the image forming apparatus100. Both ends of the whole conveying member31within the collected toner container30include a conveyance screw. Rotation of the conveyance screw agitates the waste toner stored in the collected toner container30. At the same time, the waste toner entered from the inlet27(refer toFIG. 2) close to the sheet pathway R of the collected toner container30is conveyed in the horizontal direction and toward the one end side of the collected toner container30in the toner conveying direction α as shown inFIG. 5. As illustrated inFIG. 2, the toner conveying direction α is a direction in which the waste toner moves away from the sheet pathway R of the image forming apparatus100.

As described above, the present embodiment uses polymerized toner having a circularity of from 0.96 to 0.98 to reduce a sliding load between toner particles of waste toner. Therefore, even if the collected toner container30of the present embodiment includes a single conveying member (i.e., the conveying member31), waste toner can be uniformly stored in the collected toner container30. It is to be noted that the collected toner container30can include multiple conveying members31(i.e., the conveying members31) if required.

As illustrated inFIG. 3, the toner full detection mechanism32that is disposed downstream from the conveying member31in the toner conveying direction α includes a seal member35, a base member36, a moving unit37, and a detection unit38. The base member36is a resin molding and is detachably attached to the body101of the image forming apparatus100. One end of the collected toner container30is detachably attached to the base member36. The detection unit38includes a light emitting element38aand a light receiving element38b(as illustrated inFIG. 8). Both the light emitting element38aand the light receiving element38bare attached to the base member36. The base member36functions as a supporting member to pivotably support the moving unit37. It is to be noted that the base member36may be provided integrally with the body101of the image forming apparatus100or with the collected toner container30.

With reference toFIG. 6, a description is give of a configuration of the toner collection unit14detached from the base member36.

FIG. 6is a front view illustrating the toner collection unit14from the one end side after the base member36is removed therefrom.

As illustrated inFIG. 6, the seal member35according to the present embodiment is provided with a flexible seal40and a frame41. The frame41is a rectangular frame to hold around the flexible seal40. The flexible seal40includes soft material, e.g., rubber or resin, having a thickness of approximately 0.1 mm. By including such soft material, the flexible seal40has flexibility to change the shape thereof due to a pressing force exerted from the waste toner stored in the collected toner container30. The frame41has rigidity to retain the shape of the seal member35. As long as this rigidity of the frame41can be maintained, the frame41can be formed by optional material such as rubber, resin, or metal. It is preferable that the flexible seal40and the frame41are integrally formed by a method of insert molding or vulcanized adhesion.

With reference toFIGS. 7 and 8, a description is given of a configuration of the moving unit37and the seal member35.

FIG. 7is an enlarged cross-sectional view illustrating the moving unit37and the seal member35ofFIG. 5.FIG. 8is a perspective view illustrating a whole configuration of the moving unit37.

The collected toner container30includes an end surface30aat one end thereof. As illustrated inFIG. 7, an opening42is formed in the end surface30a.The opening42has a rectangular shape, when seen from a planar view. The seal member35is provided outside the end surface30aand is fixed to an adjacent area of the opening42by a suitable method such as adhesion. By so doing, the opening42of the collected toner container30is sealed by the seal member35. Before waste toner is stored in the collected toner container30, which is hereinafter referred to as an “initial condition”, the flexible seal40has a cross-sectional recessed shape with a recessed portion43protruding inside the collected toner container30and stays in the opening42. The shape of the recessed portion43of the flexible seal40is optionally selectable. In the present embodiment, the recessed portion43has a shape close to a truncated square pyramid as illustrated inFIG. 6.

As illustrated inFIGS. 7 and 8, the moving unit37has a long body as a whole and integrally includes a contact portion45, a weight46, a link portion47, and a shaft48.

The contact portion45is provided at one end (i.e., a top end in the present embodiment) of the moving unit37. The weight45is provided at the other end (i.e., a bottom end in the present embodiment) in a longitudinal direction of the moving unit37. The link portion47links the contact portion45and the weight46. The shaft48extends in a direction perpendicular to a longitudinal direction of the link portion47. The moving unit37is preferably a resin molding so as to make the moving unit37lighter in weight.

The shaft48of the moving unit37is rotatably supported by the base member36via a bearing or bearings. With this configuration, the moving unit37is rotatable about a rotation axis O that is the center of the shaft48in a positive direction indicated by a solid line inFIG. 7to come close to the opening42and in an opposite direction indicated by a dashed line inFIG. 7to move away from the opening42.

The shaft48of the moving unit37is disposed at a position that is substantially in the middle between the one end (the top end) of the moving unit37and the other end (the bottom end) thereof and shifted away from the collected toner container30with respect to a straight line connecting both ends thereof. In this case, gravity G of the moving unit37is located at a position shifted from the rotation axis O toward the collected toner container30. Therefore, rotational moment generated by the aid of gravity of the moving unit37in a positive direction (a direction indicated by a solid line) constantly acts on the moving unit37.

According the above-described structure, the moving unit37is constantly biased in the positive direction of rotation. To position the moving unit37in the initial condition, the base member36has a stopper49to regulate rotation of the moving unit37in the positive direction, as illustrated inFIG. 7. Accordingly, with the moving unit37positioned by the stopper49, the contact portion45of the moving unit37is lightly in contact with the frame41of the seal member35or is separated from the frame41with a gap. Hereinafter, a position where the moving unit37is located after being positioned by the stopper49is referred to as an “initial position”.

As illustrated inFIG. 8, the contact portion45is a thin plate having a width greater than a width of the link portion47. The contact portion45includes a contact surface45athat is a flat surface without unevenness to contact the flexible seal40.

As illustrated inFIG. 4, the contact portion45has a width W1that is greater than a width W2of the recessed portion43of the flexible seal40(indicated by a broken line) inside the frame41(W1>W2). Consequently, extended portions50aand50bthat extend out of the recessed portion43of the flexible seal40are formed at vertical edges of both end sides of the contact portion45inFIG. 4. A tip of the contact portion45extends beyond an upper edge of the recessed portion43of the flexible seal40. According to this structure, an extended portion50cthat extends out of the recessed portion43of the flexible seal40is formed at the tip of the contact portion45. The extended portions50athrough50cformed on the contact portion45function as regulators to regulate or prevent the contact portion45from coming into the recessed portion43of the flexible seal40.

A detection unit38that functions as a detector is disposed in the vicinity of the moving unit37to detect movement of the moving unit37. For example, as illustrated inFIG. 8, the detection unit38can be a photointerrupter including the light emitting element38aand the light receiving element38b.In this case, the light emitting element38aand the light receiving element38bare disposed facing each other in a direction in which the rotation axis O of the moving unit37extends (or the shaft48extends). At the same time, a part of the moving unit37at the initial position (e.g., the link portion47) is disposed on a light pathway that runs between the light emitting element38aand the light receiving element38bso as to block the light pathway. By so doing, when the moving unit37moves from the initial position by an amount greater than a given amount, the moving unit37shifts out of the light pathway and the light receiving element38bstarts to receive the light emitted from the light emitting element38a.According to a light receiving signal issued from the light receiving element38b,the detection unit38can detect that the moving unit37moves by the amount greater than the given amount.

Now a description is given of functions of the toner collection unit14.

As previously described, the flexible seal40in the initial condition has the cross-sectional recessed shape with the outward recessed portion43as illustrated inFIGS. 5 and 7. The waste toner collected from the photoconductor cleaning device5and the belt cleaning device13and conveyed to the collected toner container30is conveyed toward the one end side of the collected toner container30in accordance with rotation of the conveying member31.

When the waste toner stored in the collected toner container30accumulates beyond a given amount for storage, the waste toner that is pushed to the one end side of the collected toner container30by the conveying member31receives a conveyance force of the conveying member31to exert a pressing force to the flexible seal40. With this action, the flexible seal40starts to bulge outward as illustrated inFIG. 9(a). In the present embodiment, the flexible seal40is disposed at the end surface30aof the collected toner container30, which is a downstream side of the collected toner container30in the toner conveying direction α of the conveying member31. Therefore, the conveyance force of the conveying member31is transmitted to the flexible seal40indirectly via the waste toner in the collected toner container30. Accordingly, the flexible seal40can be bulged out smoothly.

As waste toner is accumulated in the collected toner container30, the flexible seal40is bulged out to be flat as illustrated inFIG. 9(b), so that the flexible seal40contacts the contact portion45of the moving unit37. As accumulation of the waste toner in the collected toner container30continues, the flexible seal40is further protruded outwardly to change to the cross-sectional recessed shape as illustrated inFIG. 9(c). At this time, the contact portion45is pressed by the flexible seal40, so as to rotate the moving unit37in the opposite direction. When the flexible seal40is bulged outward to its limit, the moving unit37(i.e., the link portion47in the present embodiment) moves out of the light pathway. Consequently, the light receiving element38breceives the light emitted from the light emitting element38aand issues the light receiving signal. With this operation, the detection unit38detects that the waste toner stored in the collected toner container30approaches the toner full state, and a message reporting the detection result addressed to user is displayed on an operation panel of the image forming apparatus100.

While the conveying member31is rotating, the waste toner flows in the collected toner container30in respective directions indicated by arrows E1through E3inFIG. 5and in respective directions indicated by arrows F1through F4. In response to the flows of the waste toner, the flexible seal40in the initial condition usually starts to be bulged out from an area adjacent to the conveying member31.

By contrast, the directions of flow of waste toner depend on a state of accumulation of the waste toner in the collected toner container30. Therefore, a dominant flow cannot be primarily determined among the waste toner flows in the directions E1through E3and F1through F4. Since the flexible seal40of the present embodiment is located in an obliquely downward direction of the conveying member31, the flexible seal40starts to inflate from either one of a region including a top portion “h” and a region including a bottom portion “i” of the recessed portion43having a truncated square pyramid shape inFIG. 5. Further, the flexible seal40starts to inflate from either one of an upper side region including a slope “j” or a vertical side region (close to the conveying member31) including a slope “k” of the recessed portion43having the truncated square pyramid shape inFIG. 6.

Thus, the flexible seal40is bulged out irregularly and unstably, and therefore it is difficult to predict the inflation of the flexible seal40correctly. Therefore, similar toFIG. 1of the related art configuration, if the contact portion45is in the recessed portion43of the flexible seal40from the initial condition of the seal member35, irregular inflation of the flexible seal40causes the contact portion45to be caught by the flexible seal40. With this action, rotation of the moving unit37in the opposite direction is disturbed. As a result, it is likely that a time to detect the toner full state of the collected toner container30delays.

Different from the above-described configuration similar to that illustrated inFIG. 1, the configuration according to the present embodiment includes the extended portions50athrough50cfunctioning as the regulators on the contact portion45of the moving unit37. Therefore, the contact portion45can be logically prevented from entering into the recessed portion43of the flexible seal40(closer to the top portion “h” than a rising portion43aof the recessed portion43inFIG. 6) in the initial condition. In this case, the flexible seal40contacts the contact portion45after inflation of the flexible seal40becomes stable, and therefore the chances that the flexible seal40is caught by the contact portion45decreases. Along with the flexible seal40being bulged out to change the shape, the moving unit37can be rotated in the opposite direction smoothly. Accordingly, the detection time of the toner full state of the collected toner container30can achieve higher precision, thereby preventing leakage of waste toner.

In the present embodiment, the contact portion45includes the contact surface45ahaving the flat surface without irregularity, thereby preventing the flexible seal40from being caught further with respect to the contact portion45.

In the present embodiment, the stopper49determines the initial position of the moving unit37to prevent that the contact portion45comes into the recessed portion43of the flexible seal40. Accordingly, in the configuration of the present embodiment, not only the extended portions50athrough50cof the contact portion45but also the stopper49function as regulators to regulate or prevent the contact portion45coming into the recessed portion43. In this case, the regulators are provided to both the moving unit37and a supporting member (i.e., the base member36) that supports the moving unit37. For example, assuming the width W1of the contact portion45is smaller than the width W2of the recessed portion43of the flexible seal40inside the frame41(W1<W2), even when the stopper49is not provided to the base member36, the extended portions50athrough50cfunction as the regulators to prevent the contact portion45entering the recessed portion43. By contrast, even when the extended portions50athrough50care not provided to the contact portion45, the stopper49functions as the regulator to prevent the contact portion45coming into the recessed portion43. According to the regulation of entrance of the contact portion45to the recessed portion43by the extended portions50athrough50cand/or the stopper49, the above-described effect can be achieved.

The extended portions50athrough50cof the contact portion45may not need to be provided sequentially along each line of the contact portion45. That is, the extended portions50athrough50cmay be provided in a partial region of each line of the contact portion45. In this case, the extended portions50athrough50care in a form of an arm projecting from the contact portion45. Further, there are three extended portions corresponding to the number of the extended portions50athrough50cin the present embodiment. However, the number of extended portions is not limited thereto. For example, the contact portion45can have one, two, four or more extended portions.

Further, if the contact portion45includes the extended portions50athrough50cas described in the present embodiment, no gap is formed between an edge of the contact portion45and an inner surface of the opening42of the collected toner container30(seeFIG. 7). Therefore, when the flexible seal40starts to bulge out from the initial condition, even if the flexible seal40is changed into any shape, it can be prevented that a part of the flexible seal40enters into the gap so that the flexible seal40is caught by the contact portion45(seeFIG. 13). Accordingly, an increase in transfer resistance of the moving unit37due to the flexible seal40being caught by the contact portion45can be avoided. As a result, a delay in detecting the toner full detection can be prevented reliably.

With reference toFIGS. 10 and 11, a description is given of the configuration and functions of the moving unit37. Even though the seal member35is not illustrated inFIG. 10, a direction indicated by arrow “X” represents a seal inflation direction of the flexible seal40of the seal member35.

As illustrated inFIG. 10, a curved line D represents a locus of center of gravity of the moving unit37when the moving unit37is rotated in the opposite direction. Focusing on a distance M between a line extending from the gravity G in a gravity direction and the rotation center O, as the moving unit37of the present embodiment rotates in the opposite direction, the distance M becomes shorter or smaller. It means that the moment of rotation or torque of the moving unit37in the positive direction acting on the moving unit37becomes smaller as the rotation of the moving unit37approaches to the end in the opposite direction.

While the flexible seal40is changing the shape from the cross-sectional recessed shape as illustrated inFIG. 9(a) (a drawing on the left) to the flat shape as illustrated inFIG. 9(b), as the inflated area of cross section of the flexible seal40increases, the load that the flexible seal40receives from the waste toner increases. By contrast, while the flexible seal40is bulging out from the flat shape as illustrated inFIG. 9(b) (a drawing at the center) to a cross-sectional protruding shape as illustrated inFIG. 9(c) (a drawing on the right), as the amount of inflation of the cross sectional area of the flexible seal40increases, a contact area of the flexible seal40and the contact portion45of the moving unit37decreases. Therefore, the load (pressure) acting on the contact portion45via the flexible seal40decreases as the amount of bulging out the flexible seal40increases.

As described above, the shape of the moving unit37in this case is designed such that the moment of rotation acting on the moving unit37decreases as the rotation of the moving unit37in the opposite direction approaches to the end. By so doing, the moving unit37is rotated in the opposite direction smoothly along with inflation of the flexible seal40. Accordingly, a delay in detecting the toner full state of the collected toner container30can be prevented more reliably.

As illustrated by two-dot chain lines inFIG. 11, the position of the contact surface45aof the contact portion45changes when the moving unit37rotates in the opposite direction. Also, arrows provided adjacent to the moving unit37indicate the movement loci of different regions on the contact surface45adrawn while the moving unit37is rotating in the opposite direction. Since the movement loci of the regions on the contact surface45aare substantially identical to the seal inflation direction X of the flexible seal40, the contact surface45ain rotation in the opposite direction does not slidably contact the flexible seal40. Therefore, a friction force generated between the contact surface45aand the flexible seal40does not hinder or stop rotation of the moving unit37in the opposite direction. As a result, the delay in detecting the toner full state of the collected toner container30can be prevented more reliably.

With reference toFIG. 12, a description is given of a configuration of a moving unit according to another embodiment.

Different from the moving unit37illustrated inFIG. 4that has a structure in which the extended portions50athrough50care provided at both ends and top end of the contact portion45thereof, a moving unit37A illustrated inFIG. 12has an extended portion50c′ that extends out of the recessed portion43of the flexible seal40from the top end of a contact portion45A. A width W3of the contact portion45A is smaller than the width W2of the recessed portion43of the flexible seal40(W3<W2).

With this configuration, the extended portion50c′ functions as a regulator that regulates or prevents the contact portion45A from entering into the recessed portion43of the flexible seal40. With the contact portion45A having this configuration, the moving unit37A can be lighter and more compact than the moving unit37illustrated inFIG. 4.

It is to be noted that an extended portion may be provided at the top end of the contact portion45as illustrated inFIG. 12. Alternatively, extended portions may be provided at both lateral ends of the contact portion45or an extended portion may be provided at either one of both lateral ends of the contact portion45.

With reference toFIG. 13, a description is given of a configuration of a moving unit according to yet another embodiment.

As illustrated inFIG. 8, if the contact portion45of the moving unit37is increased in size, the moment of rotation of the moving unit37increases. This can delay detection of the toner full state of the collected toner container30. By contrast, as illustrated inFIG. 13, a moving unit37B includes a contact portion45B provided with multiple openings45b.With this configuration of the moving unit45B, the moving unit37B can achieve a decrease in weight, thereby reducing the moment of rotation of the moving unit37B. Accordingly, the delay in detecting the toner full state of the collected toner container30can be prevented.

By contrast, if the diameter of each of the openings45bis too large, the flexible seal40may enter into the openings45b.This increases the sliding load to cause a delay in detecting the toner full state of the collected toner container30. To prevent the delay of the detection, it is preferable to reduce the diameter of each of the openings45b,so as to prevent the flexible seal40coming into the opening45b.For example, if the diameter of each of the openings45bis 2.0 mm or smaller, the flexible seal40cannot enter into the opening45breliably.

It is to be noted that the present invention is not limited to the above-described embodiments and it will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention. For example, the image forming apparatus100that includes the toner collection unit14according to the above-described embodiments is a printer. However, the image forming apparatus100can be a copier, a facsimile machine, a multifunction peripheral or a multifunction printer (MFP) having at least one of copying, printing, scanning, facsimile, and plotter functions, or the like.

In the above-described embodiments, the flexible seal40is provided on the wall (an end surface)30alocated at the downstream side of the collected toner container30in the toner conveying direction α of the waste toner stored in the collected toner container30conveyed by the conveying member31. However, the position of the flexible seal40is not limited thereto. Therefore, the flexible seal40can be provided on other surface (e.g., an upper surface, a lower surface) of the collected toner container30regardless of the toner conveying direction α.

Further, the above-described embodiments show the configuration that the conveyance force of the conveying member31pressing the waste toner to bulge out the flexible seal40. However, the present invention is not limited thereto. For example, the present invention applies a configuration in which the flexible seal40is bulged out by the aid of gravity of the waste toner without using the conveying member31.