Image forming apparatus and developer container

An image forming apparatus includes an apparatus body, a developer container, an outlet, a first shutter, a cover member, a movable member, and a transmission member. The developer container is removably mountable relative to the apparatus body through an opening. The first shutter opens and closes the outlet. The cover member opens and closes the opening. The movable member is reciprocally movable in forward and reverse directions. The transmission member transmits action of the cover member to the movable member and is disposed between the cover member and the movable member. When the movable member is moved in the forward direction, the first shutter is closed. When the movable member is moved in the reverse direction, the first shutter is opened. In a terminal period of an opening operation of the cover member, a movement direction of the movable member is reversed from the forward direction to the reverse direction.

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. 2012-268450, filed on Dec. 7, 2012 in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.

INCORPORATION BY REFERENCE

The entire disclosure of each of the following U.S. Patent Applications is hereby incorporated by reference herein:U.S. patent application Ser. No. 13/907083, filed on May 31, 2013; andU.S. patent application Ser. No. 13/908434, published on Jun. 3, 2013.

BACKGROUND

1. Technical Field

This disclosure relates to an image forming apparatus and a developer container.

2. Description of the Related Art

Image forming apparatuses are used as, for example, copiers, printers, facsimile machines, and multi-functional devices having at least one of the foregoing capabilities. As one type of image forming apparatus, electrophotographic image forming apparatuses are known. In such electrophotographic image forming apparatus, since toner serving as developer is consumed with image formation, tone is replenished so that toner in a developing device runs out. As one replenishment method, a method is known of replacing a used toner cartridge with a toner cartridge filled with toner. In replacement of toner cartridges, for example, an upper cover at an upper surface of an image forming apparatus is opened, a used toner cartridge in the apparatus is removed, and a new toner cartridge is installed to a predetermined position in the apparatus.

The toner cartridge has an outlet to supply toner to a developing device disposed in an apparatus body of the image forming apparatus. A shutter is provided with the outlet to open and close the outlet so that toner may not be scattered from the outlet when the toner cartridge is removed from the apparatus body. For example, when the toner cartridge is mounted on the apparatus body, the shutter is opened to open the outlet, thus allowing toner to be supplied to the developing device. By contrast, when the toner cartridge is removed from the apparatus body, the shutter is closed to close the outlet, thus preventing toner from being scattered from the outlet to the outside of the developing device.

For example, in a shutter opening-and-closing assembly to switch a state of a shutter between an open state and a closed state, opening and closing movements of an exterior cover may be used as driving force of the shutter. For example, JP-2008-052033-A proposes a configuration of opening and closing of a shutter. An input gear is mounted on an opening-and-closing shaft of an exterior cover and rotated forward and in reverse in response to opening and closing of a cover member. The rotation movement is transmitted to the shutter via a gear train to open and close the shutter.

For the shutter opening-and-closing assembly described in JP-2008-052033-A, the input gear is rotated in response to an opening-and-closing angle of the cover member. Accordingly, during opening operation of the cover member, the shutter is moved in one of the opening and closing directions. By contrast, during closing operation of the cover member, the shutter is moved in the other of the opening and closing directions. Consequently, the shutter or a member to drive the shutter has a relatively large stroke. Such a large stroke constrains the layout to avoid conflict with surrounding components.

BRIEF SUMMARY

In at least one exemplary embodiment of this disclosure, there is provided an image forming apparatus including a recording head, an ejection detector, and a cleaner. The recording head has a plurality of nozzles to eject droplets and a nozzle face in which the plurality of nozzles is formed. The ejection detector detects ejection or non-ejection of the droplets from the recording head. The ejection detector has an electrode member disposed in an area in which the electrode member is opposable to the recording head. The droplets ejected from the plurality of nozzles of the recording head land on the electrode member. The cleaner cleans the electrode member after ejection or non-ejection of the droplets from the plurality of nozzles is detected by detection of electric changes of the electrode member generated when the droplets ejected from the plurality of nozzles of the recording head land on the electrode member in a state in which a potential difference is created between the nozzle face of the recording head and the electrode member and the nozzle face of the recording head is opposed to the electrode member. The cleaner includes a wiping member to wipe the droplets adhering to the electrode member. The wiping member and the electrode member are configured to be relatively moved in parallel to a nozzle array direction in which the plurality of nozzles is arrayed, to clean the electrode member.

In at least one exemplary embodiment of this disclosure, there is provided an image forming apparatus including an apparatus body, a developer container, an outlet, a first shutter, a cover member, a movable member, and a transmission member. The apparatus body has an opening. The developer container contains developer and is removably mountable relative to the apparatus body through the opening. Through the outlet, the developer is discharged from the developer container to an outside of the developer container. The first shutter opens and closes the outlet. The cover member opens and closes the opening of the apparatus body. The movable member is reciprocally movable in forward and reverse directions. The transmission member transmits action of the cover member to the movable member and is disposed between the cover member and the movable member. When the movable member is moved in the forward direction, the first shutter is closed. When the movable member is moved in the reverse direction, the first shutter is opened. In a terminal period of an opening operation of the cover member, a movement direction of the movable member is reversed from the forward direction to the reverse direction.

In at least one exemplary embodiment of this disclosure, there is provided a developer container including a developer containing part, an outlet, and a first shutter. The developer containing part contains developer. Through the outlet, the developer is discharged from the developer containing part to an outside of the developer containing part. The first shutter opens and closes the outlet. The developer container is mountable and removable relative to an apparatus body of an image forming apparatus through an opening of the apparatus body. The image forming apparatus includes a cover member to open and close the opening of the apparatus body, a movable member reciprocally movable in forward and reverse directions, and a transmission member to connect the cover member to the movable member. When the movable member is moved in the forward direction, the first shutter is closed. When the movable member is moved in the reverse direction, the first shutter is opened. A movement direction of the movable member is reversed from the forward direction to the reverse direction in a terminal period of an opening operation of the cover member, and the first shutter is maintained in a closed state while the movable member is moved in the reverse direction after the movement direction is reversed.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Although the exemplary embodiments are described with technical limitations with reference to the attached drawings, such description is not intended to limit the scope of the invention and all of the components or elements described in the exemplary embodiments of this disclosure are not necessarily indispensable to the present invention.

Referring now to the drawings, exemplary embodiments of the present disclosure are described below. In the drawings for explaining the following exemplary embodiments, the same reference codes are allocated to elements (members or components) having the same function or shape and redundant descriptions thereof are omitted below.

First, a general configuration and operation of a color laser printer serving as an image forming apparatus according to an exemplary embodiment of the present disclosure are described with reference toFIG. 1.

It is to be noted that the image forming apparatus is not limited to the color laser printer but, in some embodiments, is any other type of image forming apparatus. The image forming apparatus may be, for example, a monochromatic printer, other type of printer, a copier, a facsimile machine, or a multi-functional periphery having at least one of the foregoing capabilities.

As shown inFIG. 1, the image forming apparatus has an apparatus body (image forming apparatus body)100. Four process units1Y,1M,1C, and1Bk serving as image forming units are removably mounted in the apparatus body100. The process units1Y,1M,1C, and1Bk have substantially the same configurations except for accommodating developing agents of different colors, i.e., yellow (Y), magenta (M), cyan (C), and black (Bk) corresponding to different color separation components of a color image.

Specifically, each of the process units1Y,1M,1C, and1Bk includes, for example, a photoreceptor2, a charging device, a developing device4, and a cleaning device5. The photoreceptor2has, for example, a drum shape and serves as a latent image carrier. The charging device includes, for example, a charging roller3to charge a surface of the photoreceptor2. The developing device4supplies developer to a latent image on the photoreceptor2. The cleaning device5has, for example, a cleaning blade to clean the surface of the photoreceptor2. It is to be noted that, inFIG. 1, reference numerals of the photoreceptor2, the charging roller3, the developing device4, and the cleaning device5are allocated only to the process unit1Y and the reference numerals of the photoreceptors2, the charging rollers3, the developing devices4, and the cleaning devices5of the other process units1M,1C, and1Bk are omitted for simplicity. The image forming apparatus illustrated inFIG. 1uses one-component developer consisting of toner as developer. However, the developer is not limited to the one-component developer but may be, for example, two-component developer consisting of toner and carrier. In other words, the term “developer” used herein means, for example, toner as one-component developer and a mixture of toner and carrier particles as two-component developer.

Above the developing devices4of the process units1Y,1M,1C, and1Bk are disposed toner cartridges50serving as developer containers to contain toner to be replenished to the developing devices4. InFIG. 1, a separator108is disposed between the developing devices4and the toner cartridges50. The separator108forms a base member107and has four mount portions106to removably mount the corresponding toner cartridges50.

In an upper area of the toner cartridges50is disposed an exposing device6to expose the surfaces of the photoreceptors2of the process units1Y,1M,1C, and1Bk. The exposing device6includes, for example, light sources, polygon mirrors, f-θ lenses, reflection mirrors to irradiate laser light onto the surfaces of the photoreceptors2according to image data.

An upper cover109serving as a cover member is disposed at an upper portion of an apparatus body100. The upper cover109pivots around a cover shaft110so as to open and close in upward and downward directions. The exposing device6is mounted to the upper cover109. As a result, when the upper cover109is opened, the exposing device6is retracted from the upper area of the toner cartridges50. In a state in which the exposing device6is retracted, the toner cartridges50can be removed from an upper opening111of the apparatus body100.

A transfer device7is disposed below the process units1Y,1M,1C, and1Bk. The transfer device7has an intermediate transfer belt8formed of an endless belt serving as a transfer body. The intermediate transfer belt8extends between a driving roller9and a follow roller10, and when the driving roller9is rotated counterclockwise inFIG. 1, the intermediate transfer belt8is circulated (rotated) in a direction indicated by an arrow D1inFIG. 1.

Four primary transfer rollers11serving as primary transfer devices are disposed at positions opposing the four photoreceptors2. The primary transfer rollers11press an inner circumferential surfaces of the intermediate transfer belt8at the respective opposing positions, and primary transfer nips are formed at points at which pressed portions of the intermediate transfer belt8contact the photoreceptors2. The primary transfer rollers11are connected to power sources, and predetermined direct current (DC) voltage and/or alternating current (AC) voltage are supplied to the primary transfer rollers11.

A secondary transfer roller12serving as a secondary transfer device is disposed at a position opposing the driving roller9. The secondary transfer roller12presses an outer circumferential surface of the intermediate transfer belt8, and a secondary transfer nip is formed at a position at which the secondary transfer roller12contacts the intermediate transfer belt8. Similarly with the primary transfer rollers11, the secondary transfer roller12is connected to a power source, and predetermined direct current (DC) voltage and/or alternating current (AC) voltage are supplied to the secondary transfer roller12.

At a right end (inFIG. 1) of the outer circumferential surface of the intermediate transfer belt8, a belt cleaning device13is disposed to clean the surface of the intermediate transfer belt8. A waste-toner transport hose extending from the belt cleaning device13is connected to an inlet of a waste-toner container14disposed below the transfer device7.

Below the apparatus body100is disposed a feed tray15to accommodate recording media S. The feed tray15has a feed roller16to feed the recording media S accommodated in the feed tray15. Above the apparatus body100is disposed a pair of output rollers17to output the recording media S to an outside of the apparatus body100. The upper cover109is provided with an output tray18to stack the recording media S output by the pair of output rollers17. The recording media used herein includes not only plain sheets of paper, for example, paperboards, envelopes, coated paper (or art paper), tracing paper, and overhead projector (OHP) sheets.

The apparatus body100includes a transport path R to transport the recording media S from the feed tray15to the output tray18through the secondary transfer nip. At a position upstream from the secondary transfer roller12in a transport direction of a recording medium S on the transport path R, a pair of registration rollers19serving as a transport device is disposed to transport the recording medium S to the secondary transfer nip at a proper transport timing. A fixing device20is disposed at a position downstream from the secondary transfer roller12in the transport direction.

The above-described image forming apparatus operates, for example, as follow. When an imaging operation is started, the photoreceptors2of the process units1Y,1M,1C, and1Bk are rotated clockwise inFIG. 1and a surface of each photoreceptor2is uniformly charged with a predetermined polarity by the charging roller3. Based on image information of a document read by an image reading device, the exposing device6irradiates a laser light onto the charged surface of each photoreceptor2to form an electrostatic latent image on the surface of each photoreceptor2. At this time, image information exposed to each photoreceptor2is single-color image information formed by separating a desired full color image into each of yellow, magenta, cyan, and black color information. As described above, each developing device4supplies toner onto the electrostatic latent image to make the electrostatic latent images visible as a toner image.

Subsequently, the driving roller9extending taut the intermediate transfer belt8is rotated to circulate the intermediate transfer belt8in the direction indicated by the arrow D1inFIG. 1. A voltage having a polarity opposite a charged polarity of toner is controlled so as to maintain a constant voltage or current, and supplied to each primary transfer roller11. As a result, a transfer electric field is formed at each primary transfer nip between each primary transfer roller11and the corresponding photoreceptor2. By the transfer electric fields formed at the primary transfer nips, toner images of the respective colors on the photoreceptors2are transferred one on another onto the intermediate transfer belt8. Thus, the intermediate transfer belt8bears a full-color toner image on the surface thereof. Residual toner remaining on each photoreceptor2without being transferred onto the intermediate transfer belt8is removed by the cleaning blade of the cleaning device5.

In the feed tray15, the feed roller16is rotated to feed a recording medium S from the sheet feed tray15to the transport path R. The recording medium S fed to the transport path R is further fed to the secondary transfer nip between the secondary transfer roller12and the intermediate transfer belt8by the pair of registration rollers19at a proper timing. At this time, the secondary transfer roller12is supplied with a transfer voltage having a polarity opposite a charged polarity of toner forming the full-color toner image on the intermediate transfer belt8. As a result, a transfer electric field is formed at the secondary transfer nip. By the transfer electric field formed at the secondary transfer nip, the full-color toner image on the intermediate transfer belt8is collectively transferred onto the recording medium S. In addition, residual toner remaining on the intermediate transfer belt8after the secondary transfer is removed by the belt cleaning device13, and removed toner is sent and collected into the waste-toner container14.

Then, the recording medium S having the full-color toner image transferred thereon is transported to the fixing device20, and the fixing device20fixes the full-color toner image on the recording medium S. The recording medium S is output to the outside of the apparatus body100by the pair of output rollers17and stacked on the output tray18.

The above description relates to image forming operation for forming a full color image on a recording medium. In other image forming operation, a single color image can be formed by any one of the process units1Y,1M,1C, and1Bk, or a composite color image of two or three colors can be formed by two or three of the process units1Y,1M,1C, and1Bk.

As illustrated inFIG. 2, each of the developing devices4has a development housing40to accommodate toner, a developing roller41serving as a developer carrier to carry toner, a supply roller42serving as a developer supply member to supply toner onto the developing roller41, a developing blade43serving as a regulation member to regulate the amount of toner on the developing roller41, and two conveyance screws44and45serving as conveying members to covey toner.

An interior of the development housing40is divided into a first compartment E1at an upper side and a second compartment E2at a lower side inFIG. 2by a partition wall48having communication ports48a. The communication ports48aare disposed at opposed ends of the partition wall48(at front and rear sides in a direction perpendicular to a surface of a sheet on whichFIG. 2is printed). In other words, the first compartment E1and the second compartment E2are communicated with each other at positions at which the communication ports48aare formed.

In the first compartment E1is disposed the conveyance screw44. In the second compartment E2are disposed the conveying screw45and the supply roller42. The conveying screw45conveys toner in a direction opposite a direction in which the conveyance screw44conveys toner. At an opening of the second compartment E2opposing the photoreceptor2are disposed the developing roller41and the developing blade43. The supply roller42contacts the developing roller41to form a nipping portion. By rotating the supply roller42in a counter direction (indicated by an arrow RT1inFIG. 2) relative to a rotation direction of the developing roller41(indicated by an arrow RT2inFIG. 2), toner in the development housing40is supplied to the developing roller41. The developing roller41conveys developer retained on a surface thereof to respective positions opposing the developing blade43and the photoreceptor2.

When toner borne on the developing roller41passes a nipping portion between the developing roller41and the developing blade43, the thickness of a layer of toner is regulated and, simultaneously toner is charged by friction. When toner on the developing roller41is conveyed to the position (developing area) opposing the photoreceptor2, toner is electrostatically transferred onto an electrostatic latent image on the photoreceptor2to form a toner image.

The toner cartridges50serving as a developer container has a container body70including a developer containing part51to contain toner. The container body70has, for example, an outlet52, a conveyance screw53, and an agitator54. Through the outlet52, toner is discharged from the developer containing part51to an outside of the container body70. The conveyance screw53serves as a conveyance member to convey toner in the developer containing part51to the outlet52. The agitator54serves as an agitating member to agitate developer in the developer containing part51. The outlet52is provided at a lower position of the developer containing part51. At each of the mount portions106of the separator108to mount the toner cartridges50is formed a replenishment port49connected to the outlet52of the toner cartridges50.

The toner cartridge50ofFIG. 2is removably mounted to the apparatus body100as a single unit provided separately from the process units1Y,1M,1C, and1Bk. However, it is to be noted that the configuration of the toner cartridge is not limited to the above-described configuration. In some embodiments, for example, the toner cartridge50is an integral part of a process unit including the photoreceptor2, the charging device3, the developing device4, and the cleaning device5so that the process unit including the toner cartridge50is removably mountable relative to the apparatus body100as a single unit. Alternatively, in some embodiments, the toner cartridge50is an integral part of the developing device4to form a developing unit, and the developing unit is removably mountable relative to the apparatus body100.

Next, toner replenishment operation on the developing device4is described below.

Replenishment of toner to the developing device4is performed when the amount of toner in the development housing40is not greater than a threshold value. When the amount of toner in the development housing40is not greater than the threshold value, the conveyance screw53and the agitator54in the toner cartridges50start rotating. Rotation of the conveyance screw53conveys toner to the outlet52, and toner is replenished from the outlet52into the first compartment E1of the development housing40. In addition, when the agitator54is rotated, toner is agitated in the toner cartridges50and delivered to a rotation area of the conveyance screw53. When the amount of toner in the development housing40is greater than a predetermined threshold value, rotation of the conveyance screw53and the agitator54is stopped and replenishment of toner ends.

In the developing device4, when toner is replenished, the conveyance screw44in the first compartment E1and the conveying screw45in the second compartment E2are rotated. As a result, toner in the first compartment E1is conveyed in a direction opposite a direction in which toner in the second compartment E2is conveyed. When toner is conveyed to a downstream end of each of the first compartment E1and the second compartments E2in the conveyance direction, toner passes through one of the communication ports48aformed at the opposed ends of the partition wall48and is delivered into the other of the first compartment E1and the second compartments E2(i.e., from the first compartment E1to the second compartment E2or from the second compartment E2to the first compartment E1). Toner delivered into the other component is conveyed by the conveyance screw44or45in the other component and returned into the original one of the first compartment E1and the second compartment E2thorough the other of the communication ports48a. By repeating the above-described operation, toner is circulated between the first compartment E1and the second compartment E2. As a result, newly replenished toner is mixed with toner in the development housing40, a uniform state of toner (uniform rate of newly replenished toner in the entire toner) is created, thus preventing occurrence of a failure, such as uneven distribution of color or background stain.

FIG. 3is an external perspective view of the toner cartridge50.

As illustrated inFIG. 3, the toner cartridge50has the container body70, a gear cover57, and a shutter60. The container body70includes an upper case55and a lower case56. The gear cover57covers a side face of one end in a longitudinal direction of the container body70. The shutter60is disposed at the same end of the container body70. The container body70is produced by bonding rims of openings of the upper case55and the lower case56each other by, e.g., welding or adhesion. In an internal space of the container body70are accommodated toner, the conveyance screw53, and the agitator54. In the gear cover57is disposed a plurality of gears serving as torque transmitters to transmit driving force from the apparatus body to the conveyance screw53and the agitator54.

At one end of the container body70in the longitudinal direction is disposed an outer shutter60serving as a second shutter to open and close the outlet52. The outer shutter60is rotatable along an outer circumferential surface of a cylindrical portion of the container body70and movable between an open position at which the outlet52shown inFIG. 2is open and a closed position at which the outlet52is closed.

FIG. 4is a perspective view of the toner cartridges50in a state in which the upper case55and the gear cover57are removed from the toner cartridges50. A conveyance driving gear62, an agitation driving gear63, and a torque transmission gear64illustrated inFIG. 4are accommodated in the gear cover57. The conveyance driving gear62and the agitation driving gear63are mounted on respective rotation shafts of the conveyance screw53and the agitator54that protrude beyond a side face of the lower case56to the outside of the lower case56. The torque transmission gear64engages the conveyance driving gear62and the agitation driving gear63to transmit rotation torque.

The apparatus body100is mounted with a body-side driving gear105(FIGS. 11 and 12). When the toner cartridges50is mounted on the mount portions106of the apparatus body100, the conveyance driving gear62engages the body-side driving gear105. In this state, when the body-side driving gear105is rotated, the conveyance driving gear62, the torque transmission gear64, and the agitation driving gear63are rotated in directions indicated by arrows M1, M2, and M3inFIG. 4, thus rotating the conveyance screw53and the agitator54. The conveyance driving gear62ofFIG. 4is a two-step gear having a larger-diameter gear part and a smaller-diameter gear part. The torque transmission gear64engages the larger-diameter gear part and the body-side driving gear105engages the smaller-diameter gear part.

FIGS. 5 and 6are side views of the toner cartridges50in a state in which the gear cover57is removed from the toner cartridges50. As illustrated inFIG. 5, the torque transmission gear64is movable between an operating position and a retracted position. At the operating position, the torque transmission gear64engages the conveyance driving gear62and the agitation driving gear63to transmit torque. At the retracted position, the torque transmission gear64is disengaged from the conveyance driving gear62and the agitation driving gear63. Specifically, as illustrated inFIG. 7, the torque transmission gear64is held by a gear holder71that is supported so as to be rotatable around a rotation shaft530of the conveyance screw53(or the rotation shaft530). When the gear holder71is rotated in a forward or reverse direction, the position of the torque transmission gear64is shifted between the operating position illustrated inFIG. 5and the retracted position illustrated inFIG. 6.

As illustrated inFIG. 7, the outer shutter60serving as the second shutter is an integral part of the gear holder71. When the gear holder71is rotated around the rotation shaft530, the outer shutter60is rotated around the rotation shaft530of the conveyance screw53with the rotation of the gear holder71. In such a case, as illustrated inFIG. 5, in a state in which the torque transmission gear64is at the operating position, the outlet52is opened by the outer shutter60. As illustrated inFIG. 6, in a state in which the torque transmission gear64is at the retracted position, the outlet52is closed by the outer shutter60.

As illustrated inFIGS. 5 and 6, a tension spring72is disposed between the gear holder71and the container body70. One end of the tension spring72is hooked to a stopper71aof the gear holder71, and the other end of the tension spring72is attached to a stopper70athat is disposed on the side face of the upper case55. By the tension (urging force) of the tension spring72, the gear holder71is urged in such a direction that the torque transmission gear64moves away from the agitation driving gear63. Thus, in a state in which no external force is applied to the gear holder71, as illustrated inFIG. 6, the torque transmission gear64is shifted to the retracted position by the tension of the tension spring72.

As illustrated inFIG. 7, the gear holder71has an operation part (or gear holder protrusion)71b. When the toner cartridges50is mounted on the mount portions106of the apparatus body100, the operation part71bcontacts an upper end of a shutter regulation member102disposed at the apparatus body100. When the toner cartridges50is removed from the apparatus body100, the operation part71bis detached from the shutter regulation member102.

FIG. 8is a cross-sectional view of the toner cartridge50cut along an axial direction thereof at a position of the conveyance screw53.

As illustrated inFIG. 8, the toner cartridge50employs a double shutter structure having an inner shutter22serving as a first shutter and the above-described outer shutter60serving as the second shutter. The inner shutter22and the outer shutter60are arranged so as to overlap in a diameter direction. The outer shutter60opens and closes an outer opening of the outlet52, and the inner shutter22opens and closes an inner opening of the outlet52.

The inner shutter22is cylindrical and has a developer outlet23at a peripheral wall thereof. By rotation of the inner shutter22around a center of a shaft thereof, the developer outlet23is switchable between an open state and a closed state. At the open state, the developer outlet23overlaps the outlet52. At the closed state, the peripheral wall of the inner shutter22overlaps the outlet52(and the developer outlet23does not overlap the outlet52). The conveyance screw53is inserted into an inner-diameter part of the inner shutter22.

The inner shutter22has a return port24to return toner, which has not been discharged from the outlet52via the developer outlet23, from the inside of the inner shutter22to the inside of the developer containing part51. The return port24is disposed at a position downstream from the developer outlet23in a conveyance direction of toner indicated by an arrow CD inFIG. 8.

At an outer-diameter side of the inner shutter22, an eave portion65of a half-cylindrical shape. The inner shutter22is rotatably held between the eave portion65and an inner wall surface of the container body70.

Without the eave portion65, it may be possible to rotatably support one end of the inner shutter22by the container body70in a single support manner. However, an inner cylindrical surface of the eave portion65acts as a bearing, thus stabilizing the rotational posture of the inner shutter22. The eave portion65has a return port67at a position corresponding to the return port24of the inner shutter22.

A seal member25of a cylindrical shape is disposed between the outer circumferential surface of the inner shutter22and an inner circumferential surface of the eave portion65and between the outer circumferential surface of the eave portion65and the inner wall surface of the container body70to prevent toner from leaking from between the outer circumferential surface of the inner shutter22and the inner circumferential surface of the eave portion65and between the outer circumferential surface of the eave portion65and the inner wall surface of the container body70.

FIG. 9Ais a cross-sectional view of the toner cartridge50cut along a I-I line ofFIG. 8in the open state in which the developer outlet23of the inner shutter22overlaps the outlet52. By contrast.FIG. 9Bis a cross-sectional view of the toner cartridge50cut along the I-I line ofFIG. 8in the closed state in which the developer outlet23does not overlap the outlet52. As illustrated inFIG. 10A, the return port24of the inner shutter22is formed so as to extend along the circumferential direction of the inner shutter22, and the return port24is more largely open in the circumferential direction than the developer outlet23. By forming the return port24of the inner shutter22as described above, a part of the return port24of the inner shutter22overlaps the return port67of the eave portion65in any of the open state shown inFIG. 9Aand the closed state shown inFIG. 9B.

FIG. 10is a side view of the toner cartridges50seen from a side on which the gear cover57is disposed.FIG. 11is a cross-sectional view of the toner cartridge50mounted on the apparatus body100, seen from a bottom side of the toner cartridge50.

As illustrated inFIGS. 10 and 11, an outer surface of the gear cover57has a slit73extending in an upward and downward direction (see alsoFIG. 3). Each of the mount portions106of the apparatus body100has a protrusion101protruding in a horizontal direction. When the toner cartridges50are installed to the apparatus body100, the protrusion101is inserted into the slit73. Conjunction of the slit73and the protrusion101provides a function of guiding the container body70along attachment and detachment directions relative to the apparatus body100and a function of positioning the container body70relative to the apparatus body100. Specifically, the slip73has a guide portion73ahaving the guiding function and a positioning portion73bhaving the positioning function. The guide portion73aranges from a lower end to a portion just below an upper narrowest portion. The guide portion73ais the upper narrowest portion. The lower end of the guide portion73ais open downward. The guide portion73ahas a uniform width except for an upper end, and the width of the upper end gradually decreases toward the positioning portion73b.

InFIG. 10, projection areas of the conveyance driving gear62, the agitation driving gear63, and the torque transmission gear64on an outer surface of the gear cover57having the slit73are shown by broken lines. An area J is a projection area of the torque transmission gear64placed at the operating position, and an area U is a projection area of the torque transmission gear64placed at the retracted position. As described above, in the toner cartridge50shown inFIG. 10, a portion of the guide portion73aof the slit73is disposed in the projection area J of the torque transmission gear64placed at the operating position. In some exemplary embodiments, the entire guide portion73ais disposed in the projection area J of the torque transmission gear64placed at the operating position. By contrast, the narrower positioning portion73bof the slit73is disposed outside the projection area J of the torque transmission gear64placed at the operating position.

As illustrated inFIGS. 10 and 11, a convex portion79(seeFIG. 3) serving as another guide portion and positioning portion is disposed at the outer side of the gear cover57. The convex portion79is formed by molding a portion of the outer circumferential surface of the gear cover57in a cylindrical shape. The convex portion79is inserted into a guide slit103of the apparatus body100. Conjunction of the convex portion79and the guide slit103provides a function of guiding the container body70along upward and downward directions relative to the apparatus body100and a function of positioning the container body70relative to the apparatus body100. As described above, for the toner cartridge shown inFIG. 11, the container body70is positioned relative to the apparatus body100at two points, i.e., the positioning portion73bof the slit73and the convex portion79.

On a back surface of the gear cover57and a back side of the (container-side) positioning portion73bof the slit73, a positioning boss is disposed so as to protrude. When the gear cover57is mounted onto each of an upper case55and a lower case56, the boss is inserted into a long hole77(seeFIGS. 5 and 6) formed at a side face of the upper case55. Thus, the gear cover57is positioned relative to the upper case55.

As illustrated inFIG. 11, on the back surface of the gear cover57, a hole portion78is coaxially formed with the concave portion78. One end of the rotation shaft530protruding from the lower case56of the conveyance screw53is inserted into the hole portion78. By holding the rotation shaft530of the conveyance screw53with the hole portion78, the gear cover57is positioned relative to the lower case56.

As illustrated inFIG. 11, at an inner surface of the apparatus body100, the protrusion101and the guide slit103are provided for each mount portion106. The guide slit103vertically extends and has an opening at an upper end thereof. When the toner cartridge50is installed, the convex portion79of the toner cartridge50is inserted from the opening to the guide slit103. A receiving portion is formed at a lower end of the guide slit103to receive the convex portion79.

The body-side driving gear105is disposed at a position of the separator (seeFIG. 1) near the lower end of each guide slit103. The body-side driving gear105is rotated by a driving source disposed at the apparatus body100. With the toner cartridge50mounted on the apparatus body100, the body-side driving gear105is engaged with the conveyance driving gear62(seeFIG. 5).

On the inner surface of the apparatus body100, an urging member107is formed of, e.g., a leaf spring to urge the toner cartridge50and is disposed corresponding to each mount portion106. The urging member107presses the toner cartridge50toward the gear cover57to cause a leading end of the convex portion79to contact a slit bottom of the guide slit103. As a result, movement of the toner cartridge50in a longitudinal direction thereof (a vertical direction ofFIG. 11) is restricted, thus preventing dropping of the convex portion79from the guide slit103and dropping of the protrusion101from the container-side positioning portion73b.

Next, installation and removal of the toner cartridge50relative to the apparatus body100in the above-described exemplary embodiment are described with reference toFIGS. 12A to 12C. When the toner cartridge50is installed to the apparatus body100, a user opens the upper cover109of the apparatus body100. Then, the user installs the toner cartridge50into the apparatus body100via an upper opening111of the apparatus body100.

As the toner cartridge50is installed, as illustrated inFIG. 12B, the concave portion79of the toner cartridge50is inserted into the upper end of the guide slit103. Since the insert direction of the toner cartridge50is guided along the guide slit103during installation, the toner cartridge50can be smoothly guided to the mount portion106without being forcefully thrust into.

As illustrated inFIG. 12C, when the toner cartridge50is mounted on the mount portion106, the concave portion79of the toner cartridge50contacts the lower end (receiving portion) of the guide slit103and is positioned.

With installation of the toner cartridge50, the protrusion101is inserted into the slit73As illustrated inFIG. 12C, when the toner cartridge50is mounted on the mount portion106, the protrusion101is placed at the container-side positioning portion73bwhich is relatively narrow in the slit73.

During installation, the shutter regulation member102of the apparatus body100contacts the operation part71bof the gear holder71. As a result, against the tension (urging force) of the tension spring72, the gear holder71is rotated in a direction indicated by an arrow K inFIG. 12Cand the torque transmission gear64is placed at the operating position at which the torque transmission gear64engages the agitation driving gear63. With rotation of the gear holder71, the outer shutter60integrally provided with the gear holder71is also rotated and, as a result, the outer circumferential side of the outlet52is opened. However, in such a state (in which the toner cartridge50is mounted on the apparatus body100), the inner shutter22is still closed. During a series of operations to open the outer shutter60, the outlet52of the toner cartridge50may be instantly disconnected to the replenishment port49of the apparatus body100. In such a moment, toner may drop downward from the outlet52. However, as described above, the inner shutter22is still closed, thus preventing toner leakage.

During movement of the torque transmission gear64toward the operating position, when the torque transmission gear64approaches the slit73, the protrusion101already passes an area on the slit73in which the protrusion101might overlap the operating position, thus preventing conflict of the torque transmission gear64with the protrusion101.

When the torque transmission gear64is moved to the operating position and engages the agitation driving gear63, the conveyance screw53and the agitator54in the toner cartridge50are linked with each other so as to operate interconnectedly. Simultaneously, the outer shutter60integrally provided with the gear holder71is rotated from a position shown inFIG. 12Bto a position shown inFIG. 12C. As a result, the outlet52is opened. The outlet52opened is connected to the replenishment port49of the apparatus body100.

Then, the inner shutter22is opened. Specifically, when the upper cover109is closed, the inner shutter22is opened in conjunction with closing of the upper cover109via a shutter opening-and-closing assembly200. As a result, both the inner shutter22and the outer shutter60are open, thus allowing toner to be discharged from the outlet52.

As illustrated inFIG. 12C, in a state in which the toner cartridge50is mounted on the mount portion106, the conveyance driving gear62engages the body-side driving gear105. In this state, when the body-side driving gear105is rotated by the driving source, the driving force of the body-side driving gear105is transmitted to the conveyance screw53and the agitator54via the conveyance driving gear62, the agitation driving gear63, and the torque transmission gear64. As a result, the conveyance screw53and the agitator54are rotated. Thus, toner is replenished from the outlet52opened to the developing device4via the replenishment port49.

Next, when the toner cartridge50is removed from the apparatus body100, the upper cover109is opened (seeFIG. 1). In conjunction with opening of the upper cover109, the inner shutter22is closed by the shutter opening-and-closing assembly200. Then, a user removes the toner cartridge50from the apparatus body100.

As illustrated inFIG. 12B, when the toner cartridge50is pulled up, the shutter regulation member102of the apparatus body100detaches from the operation part71bof the gear holder71. As a result, the gear holder71is rotated by the tension (urging force) of the tension spring72to return to an original position. With the rotation of the gear holder71, the torque transmission gear64is placed at the retracted position at which the torque transmission gear64is detached from the agitation driving gear63. It is to be noted that, at this time, the protrusion101passes the area on the slit73in which the protrusion101might overlap the operating position. However, when the protrusion101arrives at the area, the torque transmission gear64is already retracted from a position on the slit73, thus preventing conflict of the protrusion101with the torque transmission gear64.

As illustrated inFIG. 12B, when the gear holder71is rotated to the original position, the outer shutter60is rotated in conjunction with the rotation of the gear holder71to close the outlet52. Thus, the outer shutter60shields the inner shutter22having a surface which is likely to be smudged when connected to the replenishment port49. As a result, even if a user touches a shutter part by hand, the hand is unlikely to be smudged. Additionally, as described above, both the inner shutter22and the outer shutter60are closed, thus significantly enhancing prevention of toner scattering from the outlet52.

As described above, when the toner cartridge50is installed, the outer shutter60is opened in conjunction with the installation of the toner cartridge50. At this time, the upper cover109is still in open state, the inner shutter22remains closed. Such a configuration prevents toner within the toner cartridge50from being scattered before the outlet52is connected to the replenishment port49. Then, by closing the upper cover109, the inner shutter22is opened, thus allowing toner to be supplied to the developing device4via the outlet52. It is to be noted that, by opening the outer shutter60before the installation of the toner cartridge50is completed, conflict of the outer shutter60with the replenishment port49can be prevented in the installation.

Additionally, when the toner cartridge50is removed, the inner shutter22is closed by opening the upper cover109, and then the outer shutter60is closed in conjunction with the removal of the toner cartridge50. Accordingly, even if toner is attached to an inner side of the outlet52, scattering of the toner is prevented. As described above, the double shutter structure having the inner shutter22and the outer shutter60reliably prevents toner from being scattered from the outlet52in installation and removal of the toner cartridge50.

Next, a configuration of the shutter opening-and-closing assembly200in an exemplary embodiment of this disclosure is described with reference toFIGS. 13 to 17B.

FIGS. 13 and 14are side views of a schematic configuration of the shutter opening-and-closing assembly200in an exemplary embodiment of this disclosure.FIGS. 15A and 15Bare schematic views of a movable member of the shutter opening-and-closing assembly200.FIG. 15Ais a side view of the movable member.FIG. 15Bis a plan view of the movable member.FIG. 16is a perspective view of a portion of the shutter opening-and-closing assembly200.FIGS. 17A and 17Bare side views of a portion of the shutter opening-and-closing assembly200. InFIG. 17A, the inner shutter22is open. InFIG. 17B, the inner shutter22is closed. It is to be noted that, as illustrated inFIG. 1, the exposing device6is mounted to the upper cover109.

For the shutter opening-and-closing assembly200, the inner shutter22is opened and closed in conjunction with opening and closing, respectively, of the upper cover109serving as a cover member shown inFIG. 1. As illustrated inFIG. 13, the shutter opening-and-closing assembly200includes, for example, a transmission member201, a movable member202, a first spring203serving as a first urging member, and a second spring204serving as a second urging member.

Around a center axis of the opening-and-closing shaft110serving as a rotational center O, the upper cover109is openable and closable between a closed position C1illustrated inFIG. 13and a maximum open position C3indicated by a broken line inFIG. 14. As illustrated inFIG. 1, the rotational center O is placed at a position in an upper part of the apparatus body100and farthest from the conveyance path R of a sheet. When the upper cover109is placed at the closed position C1, the upper cover109is locked relative to the apparatus body100by a lock mechanism. Opening of the upper cover109is performed after the lock mechanism is unlocked. When the upper cover109is placed at the maximum open position C3, the upper cover109is also locked relative to the apparatus body100by a lock mechanism. In a state in which the upper cover109is opened to the maximum open position C3, a user can install and remove the toner cartridge50relative to the apparatus body100via the upper opening111of the apparatus body100. When the upper cover109is closed from the maximum open position C3, an external force greater than a locking force of the lock mechanism is applied to the upper cover109to release the locking of the upper cover109.

The transmission member201is disposed between the upper cover109and the movable member202. The transmission member201includes a long flexible member, e.g., a metal wire. It is to be note that the material of the transmission member201is not limited to metal but may be, e.g., resin or any other suitable material. In addition, as the transmission member201, not only a single wire but double wires or twisted wire can be used. The transmission member201is not limited to wire but may be, e.g., belt or any other suitable shape.

The transmission member201has one end connected to the upper cover109and the other end connected to the movable member202. It is to be note that the connection of the transmission member201to the upper cover109and the movable member202is not limited to a particular way but may be, for example, welding or swage. Such a configuration prevents connecting portions of the transmission member201with the upper cover109and the movable member202from separating in operation. In some embodiments, the transmission member201is mounted so as to be rotatable (around a shaft extending in a vertical direction with respect to a surface of a sheet on whichFIG. 13is printed) relative to the upper cover109and/or the movable member202.

As illustrated inFIG. 13, a first connecting point208at which the transmission member201is connected to the upper cover109is disposed at a position closer to the rotational center than a second connecting point209at which the transmission member201is connected to the movable member202. For such a configuration, when the upper cover109is opened to act a pulling force from the upper cover109onto the transmission member201, the movable member202is slid toward the rotational center O by a horizontal component of the pulling force. In a state in which the upper cover109is placed at the closed position C1, as indicated by a broken line, the transmission member201preferably has a slack201aserving as play.

On a surface of the transmission member201may be coated with, e.g., low-friction coating as necessary. Even if the surface of the transmission member201is coated, such coating does not affect the positions of the transmission member201and the movable member202, and accordingly the operability of the shutter opening-and-closing assembly200is not affected.

The movable member202is a long rigid body made of, e.g., metal. As illustrated inFIG. 15A, a lower surface of the movable member202is guided by a lower guide211across a whole length thereof, and an upper surface of the movable member202is guided by a plurality of upper guides212(e.g., two inFIG. 15A) that are disposed away from each other in a longitudinal direction of the movable member202. As illustrated inFIG. 15B, both lateral faces of the movable member202are guided by a plurality of pairs (two pairs inFIG. 15A) of lateral guides213and214that are disposed away from each other in a longitudinal direction of the movable member202. By guiding the movable member202with the lower guide211, the plurality of upper guides212, and the plurality of pairs of lateral guides213and214, the movable member202is reciprocally slidable along a horizontal direction (crosswise direction on a surface of a sheet on whichFIG. 13is printed) relative to the apparatus body100. As illustrated inFIG. 13, an extension line of a moving trajectory of the second connecting point209obtained when the movable member202is slid in the horizontal direction is offset from the rotational center O by an offset amount F in the vertical direction.

The movable member202has protruding portions202aprotruding upward. The number of the protruding portions202ais the same as the number of the toner cartridges50mounted on the apparatus body100(inFIG. 13, four). The movable member202further has a spring mount portion202b. The first spring203is disposed in a compressed state between the spring mount portion202band the apparatus body100. By an urging force of the first spring203, the movable member202is constantly pressed in a horizontal direction away from the rotational center O. In descriptions below, the term “forward direction” represents a direction opposite a direction in which the movable member202is urged by the first spring203, and the term “reverse direction” represents the direction in which the movable member202is urged by the first spring203.

To define a maximum displacement of the movable member202in the reverse direction, the apparatus body100has a first stopper206to engage the movable member202. InFIGS. 13 and 14, a configuration is shown in which the first stopper206is engaged with the spring mount portion202b.

As illustrated inFIG. 16andFIGS. 17A and 17B, the inner shutter22has a projection27serving as a contact portion. The projection27is disposed at an end portion of the inner shutter22exposed from the lower case56and projects in an axial direction of the inner shutter22. A second spring204is mounted in stretched state between the projection27and an attachment portion70bdisposed at a side face of the lower case56. By urging force of the second spring204, the inner shutter22is constantly urged in a direction to close the inner shutter22. A total urging force of the second spring204of the toner cartridge50is smaller than the urging force of the first spring203.

Next, an operation of the shutter opening-and-closing assembly200in an exemplary embodiment of this disclosure is described below. As illustrated inFIG. 13, in a state in which the upper cover109is placed at the closed position C1, the movable member202is urged in the reverse direction (toward the left side inFIG. 13) by urging force of the first spring203. Accordingly, the protruding portion202aof the movable member202contacts the projection27, and the inner shutter22is held in open state against the urging force of the second spring204. As a result, the outlet52is turned into open state as illustrated inFIG. 9A.

When the upper cover109is opened from the closed position C1, the first connecting point208connecting the transmission member201to the upper cover109draws an arc-shaped trajectory having as a rotation radius “r” a distance between the first connecting point208and the rotational center O. In an initial period of the opening operation, the slack201aof the transmission member201is lost and the transmission member201is tensed. Until the transmission member201comes into tension as described above, even if the upper cover109is opened, the movable member202is not moved. As a result, the closed state of the inner shutter22is maintained. As described above, when the upper cover109is at the closed position C1, the transmission member201has the slack201aas a play. Such a configuration cancels manufacturing errors of components of the shutter opening-and-closing assembly200, thus allowing stable operation of the shutter opening-and-closing assembly200in large-scale production.

When the upper cover109is further opened after the transmission member201comes into tension, the opening operation of the upper cover109is transmitted to the movable member202via the transmission member201. As a result, the movable member202is slid in the forward direction (toward the right side inFIG. 13) by a horizontal component of a pulling force acting on the transmission member201. When the transmission member201is tensed, the transmission member201serves as a rigid body. In such a state, the shutter opening-and-closing assembly200includes three pairs of rotors and one pair of sliders and constitutes a reciprocally slider crank assembly in which the upper cover109serves as a driver. As described above, employing such a reciprocal slider crank assembly as the shutter opening-and-closing assembly200facilitates reverse of the movement direction of the movable member202in a terminal period of the opening operation of the upper cover109.

With the sliding of the movable member202in the forward direction, the first spring203is compressed to accumulate more urging force. By the sliding of the movable member202in the forward direction, the pressing force of the protruding portions202aagainst the projection27is lost. Thus, the inner shutter22is rotated counterclockwise inFIG. 13by the urging force of the second spring204. As a result, the developer outlet23is turned to the right side as illustrated inFIG. 17B, and the outlet52is closed as illustrated inFIG. 9B.

When the upper cover109is opened to an intermediate position C2indicated by a solid line inFIG. 14after the outlet52is closed with the inner shutter22, the movable member202arrives at a maximum displacement Xmax in the forward direction. Then, until the upper cover109is opened to the maximum open position C3indicated by a broken line inFIG. 14, the opening operation of the upper cover109is not transmitted to the movable member202because of flexibility of the transmission member201. At this time, the movable member202is slid in the reverse direction by the urging force accumulated in the first spring203. As described above, while the upper cover109is moved from the intermediate position C2to the maximum open position C3, the movement direction of the movable member202is reversed from the forward direction to the reverse direction, and the movable member202is slide in the reverse direction by a distance δ.

While the movable member202is reversed and moved in the reverse direction, the closed state of the inner shutter22is maintained. To maintain the closed state of the inner shutter22, when the upper cover109is placed at the maximum open position C3, a clearance is formed to have a proper width (preferably a width of the distance δ or greater) between the protruding portions202aand the projection27so that, during such reverse movement, the protruding portions202aof the movable member202does not contact the projection27to open the inner shutter22.

FIG. 18is a schematic view of the transmission member201during the above-described opening operation of the upper cover109and after the transmission member201comes into tension. InFIG. 18, the length L of the transmission member201is set to be equal to a sum of the offset amount F of the rotational center O and the rotation radius r of the first connecting point208(L=F+r).

When the upper cover109is opened, the first connecting point208is moved from a point A1to points A2, A3, A4, and A5in turn. While the first connecting point208is moved from the point A1to the point A4, the transmission member201in tensed state is gradually raised to an upright position. When the first connecting point208reaches an upmost position on the rotation trajectory (the point A4), the transmission member201is directed in the vertical direction so as to pass the rotational center O. At this time, the movable member202reaches the maximum displacement Xmax in the forward direction. Then, when the upper cover109is further opened, the movable member202is slid by the urging source of the first spring203in the reverse direction by the distance δ while the first connecting point208is moved from the point A4to the point A5. Thus, the transmission member201is returned to a tilted posture again.

FIG. 19is a graph of a relation between the open angle θ (seeFIG. 14) of the upper cover109and the displacement amount of the movable member202in the forward direction in the shutter opening-and-closing assembly200. As illustrated inFIG. 19, until the transmission member201having the slack201a comes into tension, for example, in a period s in which the open angle of the upper cover109changes from 0 degree to 10 degrees, the movable member202remains stopped. Then, as the open angle θ increases, the movable member202is slid in the forward direction. When the open angle θ reaches, for example, approximately 70 degrees, the movable member202reaches the maximum displacement Xmax. Then, in a period t in which the open angle θ reaches to 90 degrees, the movable member202is slide in the reverse direction by the distance δ.

Next, an operation of the shutter opening-and-closing assembly200performed when the shutter opening-and-closing assembly200is closed from the maximum open position C3shown inFIG. 14is described below. In a state in which the upper cover109is at the maximum open position C3, as described above, the upper cover109is locked with the lock mechanism so that the position of the upper cover109is maintain against the urging force of the movable member202. When the upper cover109is closed, for example, a user applies in a closing direction to the upper cover109a force greater than the binding force of the lock mechanism, thus unlocking the lock mechanism.

During closing operation of the upper cover109, the closing operation of the upper cover109is not transmitted to the movable member202because of flexibility of the transmission member201. The movable member202is slid in the reverse direction by urging force accumulated in the first spring203. By sliding of the movable member202in the reverse direction, the protruding portion202aof the movable member202contacts the projection27, and the movable member202is slid in the reverse direction against the urging force of the second spring204. As a result, the inner shutter22is moved to the open position. The outlet52is opened and the shutter opening-and-closing assembly200is returned to a state illustrated inFIG. 13.

As described above, during opening and closing of the upper cover109, the shape, posture, and position of the transmission member201sequentially changes. In such processes, a large space enough to encompass the movement trajectory of the transmission member201is created in the inside of the apparatus body100so that the transmission member201does not conflict with respective devices in the apparatus body100.

As described above, in the above-described exemplary embodiments, in a terminal period of the opening operation of the upper cover109, the movement direction of the movable member202is reversed from the forward direction to the reverse direction. Such a configuration shortens a reciprocal stroke of the movable member202performed with opening and closing of the upper cover109. By preventing an excess stroke of the movable member202as such, the degree of freedom of the layout around the movable member202or the inner shutter22is increased, thus enhancing the degree of freedom of design of the image forming apparatus. Additionally, the maximum open angle of the upper cover109can be set to be a relatively large value, thus enhancing the operability in installation and removal of the toner cartridge50relative to the apparatus body100.

Furthermore, since the sliding movement of the movable member202in the reverse direction during closing of the upper cover109is performed by the urging force of the first spring203accumulated during the sliding movement of the movable member202in the forward direction, a user can close the upper cover109by small power. The transmission member201is also formed of, for example, a flexible wire, thus allowing the upper cover109to be closed by a further small power. When the above-described effects are not prioritized, the transmission member201may be formed of a rigid body. In such a case, the first spring203can be omitted.

In particular, as described above, in the configuration in which the length L of the transmission member201is equal to a sum of the offset amount F of the rotational center O and the rotation radius r of the first connecting point208, as illustrated inFIG. 18, the movable member202can be reversed within an area from the upmost point A4of the movement trajectory to the point A5slightly lower than A4. In such a case, the positional relation between the initial point A1and the end position A5of the first connecting point208substantially corresponds to a positional relation between the closed position C1and the maximum open position C3of the upper cover109illustrated inFIGS. 13 and 14. Accordingly, the maximum open position C3of the upper cover109can be set to be a proper position illustrated inFIG. 14(e.g., maximum open angle of 90 degrees).

It is to be noted that the length L of the transmission member201is not limited to a length equal to the sum (F+r) of the offset amount F of the rotational center O and the rotation radius r of the first connecting point208. In some embodiments, for example, the length L of the transmission member201is greater or smaller than the sum (F+r).FIG. 20is a schematic view of change in posture of a transmission member201in an exemplary embodiment in which L>F+r is satisfied.FIG. 21is a schematic view of change in posture of a transmission member201in an exemplary embodiment in which L<F+r is satisfied.

As illustrated inFIG. 20, in the exemplary embodiment ofFIG. 20, with opening of an upper cover109, a first connecting point208is moved in substantially the same manner as that of the exemplary embodiment ofFIG. 18. On the other hand, when a first connecting point208is moved to a position lower than in the exemplary embodiment ofFIG. 18, movement direction of a movable member202is reversed. In such a case, if a maximum open position C3of the upper cover109is set so as to correspond to an end point A5of the first connecting point208, the upper cover109takes a maximum open state in a posture more tilted in an open direction than the maximum open position C3illustrated inFIG. 14. Consequently, the maximum open angle θ is relative large. Further, as illustrated inFIG. 21, in the exemplary embodiment ofFIG. 21, sliding direction of a movable member202is reversed from sliding movement in the reverse direction to sliding movement of the forward direction, which is opposite to the exemplary embodiments ofFIGS. 18 and 20. As a result, movement directions of the movable member202to open and close the inner shutter22the inner shutter22are opposite to those of the exemplary embodiment ofFIG. 13. Consequently, the configuration of the shutter opening-and-closing assembly200might be complicated.

The length L of the transmission member201, the offset amount F of the rotational center O, and the rotation radius r of the first connecting point208can be set to any value. However, for the above-described reasons, the length L, the offset amount F, and the rotation radius r are preferably set to satisfy L≧F+r, and more preferably L=F+r.

FIGS. 22 and 23are views of a shutter opening-and-closing assembly200in another exemplary embodiment of this disclosure. The exemplary embodiment illustrated inFIGS. 22 and 23differs from the exemplary embodiment illustrated inFIG. 13in that a transmission member201is wound around a direction changer216including, e.g., a pulley to change an extending direction of the transmission member201between areas upstream and downstream from the direction changer216. For such a configuration, the distance in a horizontal direction between a first connecting point208and a second connecting point209can be set to be smaller in a closed state of an upper cover109, or the positional relation in the horizontal direction between the first connecting point208and the second connecting point209can be set to be opposite to the positional relation of the exemplary embodiment illustrated inFIG. 13. Thus, the degree of freedom of layout of components is further enhanced.

InFIGS. 22 and 23, a support portion of the direction changer (e.g., pulley)216is fixed to the apparatus body100. In some embodiments, such a support portion of the direction changer216is disposed so as to be relatively movable relative to the apparatus body100(the pulley of the former direction changer216corresponds to fixed pulley, and the pulley of the latter direction changer216corresponds to moving pulley). For such a configuration, even under a condition in which, when the upper cover109is opened, excess burden acts on the pulley via the transmission member201, such failure can be prevented, thus allowing smooth opening of the upper cover109. Instead of the pulley, for example, a rolling bearing or sliding bearing is usable as the direction changer216. In such a case, the transmission member201is wound around an outer circumferential surface of the rolling or sliding bearing.

FIG. 24is a schematic view of a transmission member201including a plurality of segments201ain an exemplary embodiment of this disclosure. For example, it is conceivable to employ a configuration in which the plurality of segments201ahave a ring shape and are separatably connected to each other in a chain form. For such a configuration, when the image forming apparatus is disassembled in, e.g., maintenance, both ends of the transmission member201are removable from the upper cover109or the movable member202and dividable at a middle position, thus enhancing the degree of freedom of disassembly.

FIG. 25is a schematic view of a movable member202according to an exemplary embodiment of this disclosure in which the movable member202is segmented at multiple positions in a longitudinal direction thereof. If the movable member202is an integrated long component, the long length may give disadvantages in processing or handling. By contrast, in this exemplary embodiment, as illustrated inFIG. 25, the movable member202is segmented into a plurality of segments221and222. The segments221and222have, e.g., hooks221aand222aat respective connecting portions. Thus, the segments221and222are detachable from and connectable to each other, thus enhancing easiness of processing and operability in disassembling operation.

FIGS. 26 to 29are schematic views of an image forming apparatus according to an exemplary embodiment of this disclosure. Different parts from those of the above-described exemplary embodiments are described below.

As illustrated inFIG. 26, the image forming apparatus includes, e.g., an apparatus body100, an upper cover109, a container mount portion120, an inner cover116, and a unit mount portion130. The upper cover109is mounted on an upper portion of an apparatus body100. By opening the upper cover109, a toner cartridge50is mountable to and removable from the container mount portion120. The inner cover116is openably and closably disposed at an inner side of the apparatus body100than the container mount portion120. By opening the inner cover116, process units1Y,1M,1C, and1Bk are mountable to and removable from the unit mount portion130.FIG. 27is a schematic view of the image forming apparatus in a state in which the upper cover109is open.FIG. 28is a schematic view of the image forming apparatus in a state in which the inner cover116is open.

For example, the inner cover116is mounted on the apparatus body100so as to open and close upward and downward relative to the apparatus body100by rotating around a supporting point117. Toner cartridges50containing different colors of toner are mountable on the inner cover116. Like the above-described exemplary embodiments, an upper surface of the inner cover116has a plurality of mount portions106to mount the toner cartridges50. As illustrated inFIG. 27, in a state in which the upper cover109is open, the toner cartridges50is removable and mountable.

The process units1Y,1M,1C, and1Bk of respective colors of yellow, magenta, cyan, and black are accommodated within (at a lower side of) the inner cover116. Accordingly, when the process units1Y,1M,1C, and1Bk are installed or removed, as illustrated inFIG. 28, both the upper cover109and the inner cover116are opened. In addition, on a lower surface of the inner cover116, a plurality of exposing devices6(e.g., a light emitting diode (LED) unit) is swingably mounted to irradiate light beams onto the photoreceptors2. Thus, with opening and closing operation of the inner cover116, each of the exposing devices6is moved between a position adjacent to the photoreceptor2and a position retracted upward from the adjacent position while avoiding conflict with the process units1Y,1M,1C, and1Bk by the a guide unit.

For such a configuration, by opening the inner cover116, the toner cartridges50are retracted from an area above the process units1Y,1M,1C, and1Bk with the toner cartridges50mounted on the inner cover116, thus allowing the process units1Y,1M,1C, and1Bk to be mounted and removed without removal of the toner cartridges50. Thus, easiness of handling in replacement of the process units1Y,1M,1C, and1Bk is enhanced while suppressing risk of scattering of toner from the toner cartridges50into the inside of the apparatus body100. In the above-described configuration, the inner shutter22of each toner cartridge50is opened and closed in conjunction with opening and closing operation of the upper cover109via a shutter opening-and-closing assembly200.

On the other hand, in a state in which the inner cover116is closed, the process units1Y,1M,1C, and1Bk are not visible from the outside. Consequently, when a plurality of colors of process units1are replaced at the same time, the upper cover109and the inner cover116might be closed with one or more of the plurality of process units1not mounted. In such a case, if an outlet52of one of the toner cartridges50corresponding to a demounted process unit1is opened, toner would be scattered inside the apparatus body100.

Hence, to prevent such toner scattering, as illustrated inFIG. 29, a shutter regulation member102is disposed on each of the process units1Y,1M,1C, and1Bk to open an outer shutter60. Additionally, the inner cover116has an insertion hole118through which the shutter regulation member102is inserted. Accordingly, when the process units1Y,1M,1C, and1Bk are mounted and the inner cover116is closed, the shutter regulation member102is inserted through the insertion hole118and the shutter regulation member102is protruded into the container mount portion120.

For the above-described configuration, since the shutter regulation member102to open the outer shutter60is not disposed at positions at which the process units1Y,1M,1C, and1B are not mounted, the outer shutter60is not opened. Thus, even if the inner cover116is closed with the process units1Y,1M,1C, and1B not mounted, the outer shutter60are not opened at positions at which the process units1Y,1M,1C, and1B are not mounted, thus preventing scattering of toner.

In the above description, with reference toFIGS. 26 to 29, another exemplary embodiment of this disclosure is described. The same configuration and components/elements as those of the above-described exemplary embodiments provide the same operations and effects as those of the above-described exemplary embodiments.

The present invention is not limited to the above-described exemplary embodiments. For the number, shape, arrangement, and functions of each component, various modifications and changes can be applied within a scope of the present invention. For example, in the above-described exemplary embodiments, the configuration is described in which the outlet52is opened and closed by a double shutter including the inner shutter22and the outer shutter60. However, the present invention is applicable to a configuration in which the outlet52is opened and closed by a single shutter. In such a configuration, the single shutter is opened and closed by the shutter opening-and-closing assembly200. For example, in a configuration in which the toner cartridge50is integrated with, e.g., the developing device4and the photoreceptor2as a replaceable process unit, a housing (developer container) of the process unit may have a discharge port of waste toner removed from the photoreceptor2and the discharge port may be opened and closed with a shutter. Such a shutter can be opened and closed with the shutter opening-and-closing assembly200.

In the above-described exemplary embodiments, the inner shutter22is closed by urging force of the second spring204, and the inner shutter22is opened by contact of the movable member202against the projection27. By contrast, the shutter opening-and-closing assembly200may have a configuration in which the inner shutter22is closed by contact of the movable member202against the projection27, and the inner shutter22is opened by urging force of the second spring204.