Developer container and image forming apparatus incorporating same

A toner container includes a shutter to open and close an opening into which the nozzle is inserted, a guide rod provided together with the shutter, and a compression spring that urges the shutter in the closing direction. Further, the toner container includes a holder including a holding portion including at least two portions to support the guide rod movably in an opening and closing direction, a fitting portion having the opening, to fit into a container body, and a bridge portion to connect the holding portion and the fitting portion. A circumferential area around the guide rod and the compression spring that faces the bridge portion is smaller than a circumferential area around the guide rod and the compression spring that does not face the bridge portion. the shutter and the guide rod (or the nozzle) moves smoothly in the opening and closing direction.

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to a developer container to contain developer such as toner or the like and an image forming apparatus incorporating the same.

BACKGROUND ART

For image forming apparatuses, such as copiers, printers, facsimile machines, or multifunction peripherals (MFPs), there are toner containers (developer containers) removably installed in an apparatus bodies of the image forming apparatuses. The toner container is bottle-shaped, and a nozzle of the apparatus body is inserted into an opening of the toner container when the toner container is installed in the apparatus, to discharge toner (developer) contained in the toner container (for example, Patent Documents 1 and 2).

Specifically, in the toner container in Patent Documents 1 and 2, a shutter to open and close the opening, into which the nozzle is inserted, is formed together with a guide rod. The guide rod is movably supported in an opening and closing direction (axial direction) in the toner container by a shutter holder.

When the toner container is not installed in the apparatus, the shutter is urged by a compression spring wound around the guide rod and moves to a position to close the opening.

On the other hand, when the toner container is installed in the apparatus, the shutter is pushed by the nozzle and moves together with the guide rod to a position to open the opening in conjunction with the installation of the toner container in the apparatus. Then, as a container body, which is rotatable relative to the shutter holder, of the toner container rotates, toner (developer) contained in the toner container is discharged to an outside of the toner container via the nozzle inserted into the opening.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

In the toner container (the developer container) described above, a holder (a shutter support) to support the guide rod covers over half of the circumference of the guide rod and the compression spring (or the nozzle). As a result, the toner (developer) is agglomerated between the holder, and the guide rod and compression spring (or the nozzle). Therefore, a problem may occur that a shutter and a guide rod (or a nozzle) do not move smoothly in an opening and closing direction, causing the shutter to fail to open and close, or toner (developer) contained in the toner container is not discharge satisfactorily via the nozzle.

The present disclosure has an object to provide a toner container (a developer container) and an image forming apparatus to prevent a problem that a shutter and a guide rod (or a nozzle) do not move smoothly in an opening and closing direction, or toner (developer) contained in the toner container is not discharge satisfactorily via the nozzle.

Solution to Problem

A developer container removably installed in an apparatus body of an image forming apparatus includes a container body to contain developer; a shutter to open and close an opening of the developer container in conjunction with installation of the developer container in the apparatus body; a guide rod formed together with the shutter in one piece; a holder including a fitting portion, a holding portion, and a bridge portion; and a compression spring to urge the shutter in a direction to close the opening. The nozzle of the apparatus body is inserted into the opening. The guide rod extends in an opening and closing direction of the shutter inside the developer container. The holding portion is disposed opposite the shutter in the developer container and includes at least two portions to support the guide rod movably in an opening and closing direction. The fitting portion having the opening fits into the container body. The bridge portion connects the holding portion and the fitting portion inside the developer container. The compression spring is wound around the guide rod and faces the bridge portion between the shutter and the holding portion. The shutter is pushed by the nozzle against an urging force of the compression spring in conjunction with the installation of the developer container in the apparatus body and moves inside the developer container together with the guide rod, to open the opening, The shutter is released by the nozzle in conjunction with the removal of the developer container from the apparatus body and moves toward the opening together with the guide rod by the urging force of the compression spring, to close the opening. A circumferential area around the guide rod and the compression spring that faces the bridge portion is smaller than a circumferential area around the guide rod and the compression spring that does not face the bridge portion.

Advantageous Effects of Invention

The present disclosure can provide a developer container and an image forming apparatus in which the shutter and the guide rod (or the nozzle) moves smoothly in the opening and closing direction, or developer contained in the developer container is discharged satisfactorily via the nozzle.

DESCRIPTION OF EMBODIMENTS

It is to be noted that the suffixes Y, M, C, and K attached to each reference numeral indicate only that components indicated thereby are used for forming yellow, magenta, cyan, and black images, respectively, and hereinafter may be omitted when color discrimination is not necessary.

Referring to the drawings, embodiments of the present disclosure are described below. It is to be understood that an identical or similar reference character is given to identical or corresponding parts throughout the drawings, and redundant descriptions are omitted or simplified below.

Referring toFIGS. 1 to 3, descriptions are provided of a configuration and operation of an image forming apparatus100according to the present embodiment.

FIG. 1is a schematic view of the image forming apparatus100, which in the present embodiment is a printer.FIG. 2is a schematic enlarged view of an image forming unit6of the image forming apparatus100.FIG. 3is a schematic view of a toner supply device90(a developer supply device) of the image forming apparatus100.

As illustrated inFIG. 1, in an upper part of an apparatus body of the image forming apparatus100, four toner containers32Y,32M,32C, and32K (developer containers) respectively corresponding to yellow, magenta, cyan, and black are removably installed in toner container mounts31. The toner container32is substantially cylindrical. Hoppers81Y,81M,81C, and81K of toner supply devices90are disposed below the toner containers32Y,32M,32C, and32K, respectively.

An intermediate transfer unit15is disposed below the toner container mounts31(the toner containers32). Four image forming units6Y,6M,6C, and6K are arranged side by side, facing an intermediate transfer belt8of the intermediate transfer unit15to form toner images of yellow, magenta, cyan, and black, respectively.

Referring toFIG. 2, the image forming unit6Y for yellow includes a photoconductor drum1Y serving as an image bearer and further includes a charger4Y, a developing device5Y, a cleaner2Y, a discharger, and the like disposed around the photoconductor drum1Y. Image forming processes, namely, charging, exposure, development, transfer, and cleaning processes are performed on the photoconductor drum1Y, and thus a yellow toner image is formed on the photoconductor drum1Y.

The other image forming units6M,6C, and6K have a similar configuration to that of the yellow image forming unit6Y except the color of the toner used therein and form magenta, cyan, and black toner images, respectively. Thus, only the image forming unit6Y is described below and descriptions of the other image forming units6M,6C, and6K are omitted.

Referring toFIG. 2, the photoconductor drum1Y is rotated clockwise indicated by arrow A2inFIG. 2by a motor. The charger4Y uniformly charges a surface of the photoconductor drum1Y at a position opposite the charger4Y (a charging process).

When the photoconductor drum1Y reaches a position to receive a laser beam L emitted from an exposure device7(i.e., a writing device), the photoconductor drum1Y is scanned with the laser beam L, and thus an electrostatic latent image for yellow is formed thereon (an exposure process).

Then, the photoconductor drum1Y reaches a position facing the developing device5Y, where the electrostatic latent image is developed with toner into a yellow toner image (a development process).

When the surface of the photoconductor drum1Y carrying the toner image reaches a position facing the primary-transfer bias roller9Y via the intermediate transfer belt8, the toner image is transferred therefrom onto the intermediate transfer belt8(a primary-transfer process). After the primary transfer process, a certain amount of toner remains untransferred on the photoconductor drum1Y.

When the surface of the photoconductor drum1Y reaches a position facing the cleaner2Y, a cleaning blade2aof the cleaner2Y collects the untransferred toner on the photoconductor drum1Y (a cleaning process).

Subsequently, the surface of the photoconductor drum1Y reaches a position facing the discharger, and the discharger removes residual potential of the photoconductor drum1Y.

Thus, a sequence of image forming processes performed on the photoconductor drum1Y is completed.

The above-described image forming processes are performed in the image forming units6M,6C, and6K similar to the yellow image forming unit6Y. That is, the exposure device7disposed below the image forming units6M,6C, and6K irradiates the photoconductor drums1M,1C, and1K of the image forming units6M,6C, and6K with the laser beam L based on image data. Specifically, the exposure device7includes a light source to emit the laser beams L, multiple optical elements, and a polygon mirror that is rotated by a motor. The exposure device7directs the laser beams L to the photoconductor drums1M,1C, and1K via the multiple optical elements while deflecting the laser beams L with the polygon mirror.

Then, the toner images formed on the photoconductor drums1through the development process are transferred therefrom and deposited one on another on the intermediate transfer belt8. Thus, a multicolor toner image is formed on the intermediate transfer belt8.

The intermediate transfer unit15includes the intermediate transfer belt8, the four primary-transfer bias rollers9Y,9M,9C, and9K, a secondary-transfer backup roller12, a cleaning backup roller13, a tension roller14, and a belt cleaner10. The intermediate transfer belt8is supported by the secondary-transfer backup roller12, the cleaning backup roller13, and the tension roller14. The secondary-transfer backup roller12serves as a driving roller to rotate the intermediate transfer belt8counterclockwise indicated by arrow A1inFIG. 1.

The four primary-transfer bias rollers9Y,9M,9C, and9K are pressed against the corresponding photoconductor drums1Y,1M,1C, and1K via the intermediate transfer belt8, thereby forming primary transfer nips between the intermediate transfer belt8and the photoconductor drums1Y,1M,1C, and1K. A primary-transfer bias having a polarity opposite a polarity of toner is applied to the primary-transfer bias rollers9Y,9M,9C, and9K.

While rotating in the direction indicated by the arrow A1illustrated inFIG. 1, the intermediate transfer belt8sequentially passes through the primary transfer nips corresponding to the primary-transfer bias rollers9Y,9M,9C, and9K. Then, the single-color toner images are primarily transferred from the respective photoconductor drums1Y,1M,1C, and1K and deposited one on another on the intermediate transfer belt8.

Then, the intermediate transfer belt8carrying the multicolor toner image reaches a position facing the secondary transfer roller19. The secondary-transfer backup roller12and the secondary transfer roller19press against each other via the intermediate transfer belt8, and the contact portion therebetween is hereinafter referred to as a secondary transfer nip. The multicolor toner image on the intermediate transfer belt8is transferred onto a sheet P (a recording medium) transported to the secondary transfer nip (a secondary transfer process). A certain amount of toner remains untransferred on the intermediate transfer belt8after the secondary transfer process.

Then, the intermediate transfer belt8reaches a position facing the belt cleaner10, where the untransferred toner is collected from the intermediate transfer belt8.

Thus, a sequence of image transfer processes performed on the intermediate transfer belt8is completed.

The sheet P is transported from a sheet feeding tray26disposed in a lower portion of the apparatus body100A to the secondary transfer nip via a sheet feeding roller27and a registration roller pair28.

More specifically, the sheet feeding tray26contains a stack of multiple sheets P piled one on another. As the sheet feeding roller27rotates counterclockwise inFIG. 1, the sheet feeding roller27feeds the sheet P on the top of the stack in the sheet feeding tray26to a roller nip formed between two rollers of the registration roller pair28.

The registration roller pair28(a timing roller pair) stops rotating temporarily, stopping the sheet P with a leading edge of the sheet P nipped in the registration roller pair28. The registration roller pair28resume rotation to transport the sheet P to the secondary transfer nip, timed to coincide with the arrival of the multicolor toner image on the intermediate transfer belt8. Thus, the multicolor toner image is transferred onto the sheet P.

The sheet P carrying the multicolor toner image is transported to a fixing device20. In the fixing device20, a fixing roller and a pressure roller apply heat and pressure to the sheet P to fix the multicolor toner image on the sheet P.

Subsequently, the sheet P is discharged by a sheet ejection roller pair29outside the apparatus body100A and stacked on an output tray30as an output image.

Thus, a sequence of image forming processes performed by the image forming apparatus100is completed.

Next, a detailed description is provided of a configuration and operation of the developing device5Y referring toFIG. 2.

The developing device5Y includes a developing roller51disposed facing the photoconductor drum1Y, a doctor blade52opposed to the developing roller51, two conveying screws55disposed within the developer housings53and54, and a toner concentration detector56to detect concentration of toner in developer G. The developing roller51includes stationary magnets, a sleeve that rotates around the magnets, and the like. The developer housings53and54contain two-component developer G including carrier (carrier particles) and toner (toner particles).

With such a configuration, the developing device5Y operates as follows.

The sleeve of the developing roller51rotates in a direction indicated by arrow A3illustrated inFIG. 2. The developer G is carried on the developing roller51by a magnetic field generated by the magnets. As the sleeve rotates, the developer G moves along a circumference of the developing roller51.

The percentage (concentration) of toner in the developer G (ratio of toner to carrier) in the developing device5Y is adjusted to within a predetermined range. More specifically, the toner supply device90supplies toner from the toner container32Y to the developer housing54as the toner in the developing device5is consumed.

The two conveying screws55stirs and mixes the developer G with the toner added to the developer housing54while circulating the developer G in the developer housings53and54. In this case, the developer G moves in a direction perpendicular to the surface of the paper on whichFIG. 2is drawn. The toner in the developer G is charged by friction with the carrier and electrostatically attracted to the carrier. Then, the toner is carried on the developing roller51together with the carrier by a magnetic force generated on the developing roller51.

The developer G carried on the developing roller51is transported in the clockwise direction indicated by arrow A3inFIG. 2to a position opposite the doctor blade52. The amount of developer G on the developing roller51is adjusted by the doctor blade52, after which the developer G is carried to a developing range facing the photoconductor drum1Y. Then, the toner in the developer G is adsorbed to the electrostatic latent image formed on the photoconductor drum1Y due to the effect of an electric field generated in the developing range. As the sleeve rotates, the developer G remaining on the developing roller51reaches an upper part of the developer housing53and drops from the developing roller51.

Next, a configuration and operation of the toner supply device90(the developer supply device) illustrated inFIG. 3is described.

In the toner supply device90, the toner container32Y as the developer container is installed in the toner container mount31and rotated in a predetermined direction (the direction indicated by arrow A4inFIG. 3) so that the toner contained in the toner container32Y is discharged to the outside of the toner container32Y and guided to the developing device5Y via a sub-hopper70, to form a toner supply route (a toner transport route).

InFIG. 3, the arrangement direction of the toner container32Y, the toner supply device90, and the developing device5Y are changed for ease of understanding. In the present embodiment, the longitudinal axis of the toner container32Y and a part of the toner supply device90is perpendicular to the surface of the paper on whichFIG. 3is drawn as illustrated inFIG. 1. In addition, the orientation and arrangement of a conveyance tube95and a conveyance pipe96are also illustrated in a simplified manner.

The respective color toners contained in the toner containers32Y,32M,32C, and32K installed in the toner container mount31are supplied to the corresponding developing devices5Y,5M,5C, and5K by the toner supply devices90in an amount determined by the amount of toner consumed in the corresponding developing devices5. The four toner supply devices90are identical except for the color of the toner used in the image forming process.

Referring toFIGS. 3, 4A, and 4B, when the toner container32Y is set in the toner container mount31of the apparatus body100A, a nozzle91of the apparatus body100A pushes a shutter35of the toner container32Y and is inserted into the toner container32Y (a container body33) through an opening34a1. Accordingly, the toner contained in the toner container32Y can be discharged through the nozzle91.

Referring toFIG. 3, the toner container32Y includes the container body33with a helical protrusion33athat is disposed on an inner circumferential face of the container body33. Specifically, the helical protrusion33aprotrudes inward from an outer circumferential face to the inner circumferential face thereof and for transporting toner from the left to the right of the container body33inFIG. 3by rotation of the container body33. The toner conveyed from the left to the right inFIG. 3inside the container body33is discharged to the outside of the toner container32Y through the nozzle91.

Further, a gear37meshing with the drive gear110of the apparatus body100A is disposed on the outer peripheral surface of a head portion, which is on the right side inFIG. 3, of the container body33. When the toner container32Y is installed in the toner container mount31, the gear37meshes with the drive gear110of the apparatus body100A. As a drive motor115is driven, the driving force is transmitted from the drive gear110to the gear37, thus rotating the container body33. The drive motor115and the drive gear110serve as a drive mechanism to rotate the container body33.

A configuration and operation of the toner container32Y are described in further detail later.

Referring toFIG. 3, the conveyance screw92is disposed inside the nozzle91. As a motor93rotates the conveyance screw92, the toner flowing into the nozzle91from the inflow port91a(seeFIG. 4A) in the toner container32Y is conveyed by the conveyance screw92from the left to the right inFIG. 3. Thus, the toner is discharged through an outlet of the nozzle91to the hopper81.

The hopper81is disposed below the outlet of the nozzle91via a downward path82. A suction port83is disposed in the bottom portion of the hopper81, and the suction port83is coupled to one end of the conveyance tube95. The conveyance tube95is formed of a flexible material with low affinity for toner, and the other end of the conveyance tube95is coupled to a developer pump60(a diaphragm pump). The developer pump60is coupled to the developing device5Y via the sub-hopper70and the conveyance pipe96.

With such a configuration of the toner supply device90, as the drive motor115drives the drive gear110(i.e., the drive mechanism), the container body33of the toner container32Y rotates, thereby discharging toner from the toner container32Y through the nozzle91. The toner discharged from the toner container32Y falls through the downward path82and is stored in the hopper81. As the developer pump60operates, the toner stored in the hopper81is sucked together with air from the suction port83and is conveyed to the sub-hopper70via the conveyance tube95and the developer pump60. Then, the toner conveyed to the sub-hopper70is appropriately supplied into the developing device5Y via the conveyance pipe96. That is, the toner in the toner container32Y is conveyed in the direction indicated by broken line arrows inFIG. 3.

The toner detector86is disposed near the suction port83and indirectly detects that the toner contained in the toner container32Y is depleted (toner depletion), or a state close thereto (toner near depletion). Then, the toner is discharged from the toner container32Y based on the detection result of the toner detector86.

For example, a piezoelectric sensor or a light transmission sensor can be used as the toner detector86. The height of the detection surface of the toner detector86is set so that the amount of toner (deposition height) deposited above the suction port83is a target value.

Based on the detection result of the toner detector86, a drive timing and a drive duration of the drive motor115are controlled to rotationally drive the toner container32Y (the container body33). Specifically, when the toner detector86detects that there is no toner at the detection position, the drive motor115is driven for a predetermined time. On the other hand, when the toner detector86detects that the toner is present at the detection position, the drive motor115stops. If the toner detector86continuously detects that the toner does not exist at the detection position even when such control is performed repeatedly, a controller of the image forming apparatus100determines that the toner contained in the toner container32Y is depleted (toner depleted), or is close thereto (toner near depletion).

Next, referring toFIGS. 4A to 11, the configuration and operation of the toner container32Y (and32M,32C, and32K) as the developer container are described below.

FIGS. 5, 6, and 8A to 8Dare side views illustrating a side of the toner container32opposite the side illustrated inFIG. 4(right and left reversed drawing).

FIG. 8is a schematic view illustrating the movement of the shutter35and the guide rod36in the opening direction when the toner container32Y is set in the apparatus body100A. For ease of understanding, illustrations of the nozzle91and the container body33is omitted.

As described above with reference toFIGS. 1 to 3, the toner container32Y as the developer container contains toner as developer therein and is removable from the apparatus body100A.

Referring toFIGS. 4A, 4B, and 5, the toner container32Y (the developer container) includes the container body33, a holder34, the shutter35, the guide rod36, a compression spring38, and the like. The container body33rotatable relative to the holder34is bottle-shaped and has the helical protrusion33aformed on the inner peripheral face thereof.

When the toner container32Y is installed in the apparatus body100A (the toner container mount31), the holder34(and the shutter35, the guide rod36, and the compression spring38) is held without rotation. The drive motor115(the drive mechanism) installed in the apparatus body100A rotates the container body33, thereby discharging the toner contained in the toner container32Y through the nozzle91.

With reference toFIGS. 4A to 6, the shutter35opens and closes the opening34a1(seeFIG. 7) into which the nozzle91(installed in the apparatus body100A) is inserted in conjunction with the installation of the toner container32Y in the apparatus body100A. The shutter35is made of a resin material and molded together with the guide rod36to be described later in one-piece. The shutter35fits into the opening34a1from the inside of the toner container32Y and latched so as not to be removed from the container body33. When the shutter35closes the opening34a1, no toner is discharged from the toner container32Y, and toner can be discharged from the toner container32Y when the shutter35opens the opening34a1.

The opening34a1is a substantially columnar hole portion centered on the center of rotation of the container body33. The shutter35is shaped to fit into the opening34a1having such a columnar shape.

The guide rod36is united with the shutter35. The guide rod36extends in the opening and closing direction of the shutter35(in the lateral direction inFIGS. 4A to 6) inside the toner container32Y.

As illustrated inFIG. 5, the guide rod36is disposed so that the axis thereof substantially coincides with the center of rotation of the container body33. Accordingly, even if the unexpected rotational force indirectly acts on the guide rod36held stationary when the container body33rotates, the position of the shutter35is not likely to shift.

With reference toFIG. 7(andFIGS. 4A to 6), the holder34includes a holding portion34c, a fitting portion34a(a cap portion), a bridge portion34band the like, and is secured not to rotate when installed in the apparatus body100A.

The holding portion34cof the holder34is located on the opposite side (left side inFIGS. 4A and 4B, and right side inFIGS. 5 and 6) to the shutter35installed inside the toner container32Y. The holding portion34cincludes at least two portions to support the guide rod36movably in the opening and closing direction (two portions in the present embodiment).

More specifically, the holding portion34cis a U-shaped frame in which two holes34c1and34c2are formed at positions separated from each other in the opening and closing direction. The guide rod36fits into the two holes34c1and34c2. When combined with the bridge portion34bto be described later, the holder34is shaped like a hook. The guide rod36is supported in a state close to cantilever support by the holding portion34cdisposed on one end side of the holder34in the direction of the rotation axis of the container body33.

The fitting portion34a(the cap portion) of the holder34has the opening34a1and is rotatably fitted in the container body33. A seal is attached to the fitting portion34aso that toner does not leak out from a gap between the fitting portion34aand the container body33. The fitting portion34aincludes an engagement portion to engage with an engaged portion formed in the toner container mount31so as to secure the fitting portion34ato the toner container mount31in the circumferential direction of the container body. As a result, when the toner container32Y is installed in the apparatus body100A, the holder34is positioned at a position at which the bridge portion34bto be described later is located below the guide rod36.

The bridge portion34bof the holder34connects the holding portion34cand the fitting portion34ainside the toner container32Y (the container body33). Here, in the present embodiment, the bridge portion34bdoes not cover the periphery of the guide rod36(and the compression spring38) in a wide range, but covers the periphery of the guide rod36(and the compression spring38) in a narrow range, which is described later in detail.

Referring toFIGS. 4A to 6, the compression spring38(a biasing member) is wound around the guide rod36between the shutter35and the holding portion34cand faces the bridge portion34b. The compression spring38urges the shutter35in the direction of closing the opening34a1(to the right inFIGS. 4A and 4B, and to the left inFIGS. 5 and 6).

With such a configuration, the nozzle91pushes the shutter35in conjunction with the installation of the toner container32Y to the apparatus body100A (the toner container mount31). Thus, the shutter35moves to the inside of the toner container32Y together with the guide rod36against an urging force of the compression spring38, thereby opening the opening34a1. Specifically, the shutter35(and the guide rod36) moves as illustrated in the order ofFIGS. 4A and 4B(orFIGS. 8A, 8B, 8C, and 8D) to open the opening34a1.

On the other hand, the nozzle91releases the shutter35from the push in conjunction with the removal of the toner container32Y from the apparatus body100A (the toner container mount31), and the shutter moves together with the guide rod36toward the opening34a1by the urging force of the compression spring38, to close the opening34a1. Specifically, the shutter35(and the guide rod36) moves as illustrated in the order ofFIGS. 4B and 4A(orFIGS. 8D, 8C, 8B, and 8A) to close the opening34a1. As illustrated inFIGS. 4B and 8D, when the installation of the toner container32Y in the apparatus body100A is completed, the shutter35contacts the holding portion34c, and the compression spring38is accommodated in the recess of the shutter35. Accordingly, when the toner container32Y is set in the apparatus body100A, it is possible to prevent the toner in the container from adhering to the compression spring38.

Referring toFIG. 9, in the toner container32Y according to the present embodiments, a range in which the bridge portion34bfaces the guide rod36and the compression spring38is smaller than a range in which the bridge portion34bdoes not face the guide rod36and the compression spring38.

Therefore, when the toner container32Y is set in the apparatus body100A and the toner can be discharged, as illustrated inFIGS. 4B and 9, the nozzle91faces the bridge portion34bin a narrow range, and the wide range (the range indicated by a chain double-dashed line inFIG. 9) is opened. Specifically, in the present embodiment, the range of 270 degrees or more around the nozzle91(or the guide rod36and the compression spring38) is open so as not to face the bridge portion34b(the holder34).

With this configuration, not only when the toner container32Y is set in the apparatus body100A, but also when the toner container32Y is left alone for a long time, even if a force acts on toner between the bridge portion34bof the holder34, and the guide rod36and the compression spring38(or the nozzle91) to agglomerate the toner, a space for escape to avoid the force is sufficiently secured. Therefore, toner can be inhibited from agglomerating at that position. As a result, this configuration prevents problems that aggregation of toner hinders the shutter35and the guide rod36(or the nozzle91) from moving smoothly in the opening and closing direction, that the opening and closing failure of the shutter35occurs, and that the toner contained in the toner container32Y is not discharged satisfactorily through the nozzle91.

Further, when the nozzle91is inserted in the toner container32Y, since the periphery of the nozzle91is opened in the wide range, the toner from the inflow port91aof the nozzle91flows smoothly. Therefore, the position and the number of the inflow port91adisposed on the nozzle91can be set freely without a large restriction. That is, the toner discharge performance from the toner container32Y through the nozzle91is improved.

In the present embodiment, the bridge portion34bof the holder34guides the shutter35moving in the opening and closing direction.

Specifically, as illustrated inFIG. 9, an opposing surface of the bridge portion34bfacing the shutter35is curved along the outer periphery of the shutter35. As a result, as illustrated inFIGS. 8A to 8D, when the shutter35moves in the left-right direction inFIGS. 8A to 8D, the shutter35smoothly moves along the opposing surface of the bridge portion34b.

As illustrated inFIG. 9, the bridge portion34bincludes a rail34b1in sliding contact with the shutter35moving in the opening and closing direction. The rail34b1stands upward on both sides of the opposing surface of the bridge portion34b. With such a configuration, the shutter35does not move in the opening and closing direction while making surface contact with the opposing surface of the bridge portion34b, but moves in the opening and closing direction while being in line contact with the rail34b1. Therefore, the shutter35moves smoothly with a small sliding resistance.

Here, in the present embodiment, the two holes34c1and34c2disposed in the holding portion34chave shapes to fit the engagement portion of the guide rod36so that the shutter35and the guide rod36do not rotate.

Referring toFIG. 7, the two holes34c1and34c2of the holding portion34cof the holder34have an oval shape. The engagement portion of the guide rod36(which is the entire area of the range sliding in the hole portion) also has an oval shape so as to fit movably into the two oval holes34c1and34c2. As a result, unlike the case in which the two holes34c1and34c2and the engagement portion of the guide rod36are circular, the guide rod36(and the shutter35) does not rotate even if a force in a rotational direction acts on the guide rod36. Therefore, the shutter35moves in the opening and closing direction and opens and closes the opening34a1smoothly.

Further, in the present embodiment, as illustrated inFIGS. 10A and 10B, the two holes34c1and34c2in the holding portion34ccan be formed so that the hole shapes thereof are different from each other. In the example ofFIGS. 10A and 10B, the hole34c1has an oval shape and the other hole34c2has a cross shape that encloses the oval shape of the hole34c1when the oval shape of the hole34c1is projected. In addition, the engagement portion (the entire area of the range sliding through the hole portion) of the guide rod36has an oval shape so as to fit movably into both of the two holes34c1and34c2. With such a configuration, the movement of the shutter35and the guide rod36in the rotational direction is restricted. Further, the two holes34c1and34c2having different shapes prevent the guide rod36from twisting. In addition, since the guide rod36sliding in the two holes34c1and34c2contacts the holding portion34cat different positions, wear due to sliding of the guide rod36can be reduced.

Here, in the present embodiment, a tip36a(which is not on the side of the shutter35but on the side of the holding portion34c) of the guide rod36is branched into two like a fork as illustrated inFIG. 11. That is, a notch36a1is disposed in the tip36aof the guide rod36.

With such a configuration, the tip36aof the guide rod36has elasticity in the direction in which the notch36a1is formed (horizontal direction inFIG. 11), and the guide rod36slides without large sliding resistance while fitting into the holes34c1and34c2of the holding portion34c.

As illustrated inFIG. 7, in the present embodiment, a face of the bridge portion34bthat does not face the guide rod36and the compression spring38(which is the portion surrounded by the broken line inFIG. 7) is angular.

As a result, even when the bridge portion34bhas a small cross-sectional area, the second moment of area of the bridge portion34bincreases to strengthen the bridge portion34b.

FIGS. 12A and 12Bare side views of the holders34as variations.

The holder34illustrated inFIG. 12Aincludes the holding portion34chaving a U-shape that is different in orientation from the above-described embodiment, and the shape combined with the bridge portion34bis a substantially F-shape. In this configuration, the boundary portion between the bridge portion34band the holding portion34cis reinforced.

Further, the holder34illustrated inFIG. 12Bis different from that of the above-described embodiment in which the holding portion34cis a U-shaped frame, and the holding portion34cis a hollow-squared frame. In this configuration, the holding portion34citself can also be reinforced.

As described above, the toner container32Y (the developer container) according to the present embodiment includes the shutter35to open and close the opening34a1into which the nozzle91is inserted, the guide rod36provided together with the shutter35in one piece, and the compression spring38that urges the shutter35in the closing direction. Further, the toner container32Y includes the holder34including the holding portion34cincluding at least two portions to support the guide rod36movably in the opening and closing direction, a fitting portion34ahaving the opening34a1to fit into the container body33, and the bridge portion34bto connect the holding portion34cand the fitting portion34a. A circumferential area around the guide rod36and the compression spring38that faces the bridge portion34bis smaller than a circumferential area around the guide rod36and the compression spring38that does not face the bridge portion34b. In other words, on a cross section perpendicular to the axis of the guide rod36, a range of the bridge portion34bfacing the guide rod36(and the compression spring38) is smaller than half of an entire range of the guide rod36in the circumferential direction (in the direction of arc).

This configuration can attain that the shutter35and the guide rod36(or the nozzle91) move smoothly in the opening and closing direction, or the toner (developer) contained in the toner container32Y discharged satisfactorily via the nozzle91.

Although the descriptions above concern the toner container32Y as the developer container containing the toner (one-component developer) as developer, alternatively, the present disclosure can also be applied to a developer container containing two-component developer including toner and carrier. It is to be noted that, although the toner containers32Y contains toner in the above-described embodiments, alternatively, the toner container32Y installed in the toner supply device90(the developer supply device) can contain two-component developer including toner and carrier when used in image forming apparatuses that supply two-component developer to developing devices5Y.

In such configurations, effects similar to those described above are also attained.

Further, in the present embodiment, the nozzle91is inserted into the toner container32Y, and the toner is conveyed by rotating the conveyance screw92installed in the nozzle91, but the nozzle91can be coupled to the pump to generate a negative pressure in the nozzle91, thereby conveying the toner.

In such configurations, effects similar to those described above are also attained.

This patent application is based on and claims priority to Japanese Patent Application No. 2017-099157, filed on May 18, 2017, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.

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