Patent Publication Number: US-11048189-B2

Title: Toner container, toner supply device, and image forming apparatus including a sheet member with two portions to move toner

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is based on and claims priority pursuant to 35 U.S.C. § 119(a) to Japanese Patent Application Nos. 2019-045487, filed on Mar. 13, 2019 and 2019-168053, filed on Sep. 17, 2019, in the Japan Patent Office, the entire disclosure of each of which is hereby incorporated by reference herein. 
     BACKGROUND 
     Technical Field 
     Embodiments of the present disclosure generally relate to a toner container to store toner therein, a toner supply device incorporating the toner container, and an image forming apparatus, such as a copier, a printer, a facsimile machine, or a multifunction peripheral (MFP) having at least two of such capabilities, incorporating the toner supply device. 
     Description of the Related Art 
     In image forming apparatuses such as copiers, printers, and the like, a cylindrical toner container (toner bottle) that is removably installable in the image forming apparatus is widely used. 
     SUMMARY 
     Embodiments of the present disclosure describe an improved toner container that includes a cylindrical container body having a head with an opening in the head, a cap into which the head of the container body is inserted, and a sheet member attached inside the cap. The cylindrical container body rotates around a rotation axis extending in a longitudinal direction of the container body to transport toner contained in the container body toward the opening. The cap has a toner outlet through which toner discharged from the opening is discharged outside the toner container. The sheet member includes a first elastic-deformation portion that is elastically deformable and located near the toner outlet, and a second elastic-deformation portion that is elastically deformable and located in the container body and near the opening. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
         FIG. 1  is a schematic view illustrating a configuration of an image forming apparatus according to an embodiment of the present disclosure; 
         FIG. 2  is a cross-sectional view of an image forming unit of the image forming apparatus in  FIG. 1 ; 
         FIG. 3  is a schematic view of a toner supply device of the image forming apparatus in  FIG. 1 , in which a toner container is installed; 
         FIG. 4  is a perspective view of toner containers installed in a toner container mount of the image forming apparatus in  FIG. 1 ; 
         FIG. 5  is a perspective view of the toner container illustrated in  FIG. 3  when viewed obliquely from above; 
         FIG. 6  is a perspective view of the toner container illustrated in  FIG. 3  when viewed obliquely from below; 
         FIG. 7  is an exploded view of the toner container; 
         FIG. 8  is a perspective view of a container body of the toner container; 
         FIG. 9  is a cross-sectional view of a part of the toner container along an axial direction of rotation of the toner container; 
         FIG. 10  is a perspective, cross-sectional view of a part of the toner container; 
         FIG. 11  is a cross-sectional view of a cap of the toner container at a toner outlet of the cap; and 
         FIG. 12  is a cross-sectional view of the container body near an opening of the container body. 
     
    
    
     The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. In addition, identical or similar reference numerals designate identical or similar components throughout the several views. 
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure are described in detail with reference to drawings. It is to be understood that identical or similar reference numerals are assigned to identical or corresponding components throughout the drawings, and redundant descriptions are omitted or simplified below as required. 
     In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this patent specification is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that have the same function, operate in a similar manner, and achieve a similar result. 
     As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. 
     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. 
     Configuration and operation of an image forming apparatus  100  according to the present embodiments is described below. 
     As illustrated in  FIG. 1 , in an upper part of the image forming apparatus  100 , four toner containers  32 Y,  32 M,  32 C, and  32 K respectively corresponding to yellow, magenta, cyan, and black are removably installed in a toner container mount  70 . 
     An intermediate transfer unit  15  is disposed below the toner container mount  70 . Image forming units  6 Y,  6 M,  6 C, and  6 K are arranged side by side, facing an intermediate transfer belt  8  of the intermediate transfer unit  15  to form toner images of yellow, magenta, cyan, and black, respectively. 
     Toner supply devices  60 Y,  60 M,  60 C, and  60 K are disposed below the toner containers  32 Y,  32 M,  32 C, and  32 K, respectively. The toner supply devices  60 Y,  60 M,  60 C, and  60 K supply toner contained in the toner containers  32 Y,  32 M,  32 C, and  32 K to developing devices  5 Y,  5 M,  5 C, and  5 K (see  FIG. 2 ) of the image forming units  6 Y,  6 M,  6 C, and  6 K, respectively. 
     With reference to  FIG. 2 , it can be seen that the image forming unit  6 Y for yellow includes a photoconductor drum  1 Y and a charging device  4 Y, the developing device  5 Y, a cleaning device  2 Y, a discharge device, and the like disposed around the photoconductor drum  1 Y. Image forming processes, namely, charging, exposure, development, transfer, cleaning, and discharging processes, are performed on the photoconductor drum  1 Y, and thus a yellow toner image is formed on a surface of the photoconductor drum  1 Y. 
     The other three image forming units  6 M,  6 C, and  6 K have a similar configuration to that of the yellow image forming unit  6 Y except for the color of toner used therein and form magenta, cyan, and black toner images, respectively. Thus, only the image forming unit  6 Y is described below and descriptions of the other three image forming units  6 M,  6 C, and  6 K are omitted. 
     With reference to  FIG. 2 , it can be seen that the photoconductor drum  1 Y is rotated clockwise in  FIG. 2  by a drive motor. The charging device  4 Y uniformly charges a surface of the photoconductor drum  1 Y (charging process). 
     When the surface of the photoconductor drum  1 Y reaches a position where the surface of the photoconductor drum  1 Y is irradiated with a laser beam L emitted from an exposure device  7  (see  FIG. 1 ), the photoconductor drum  1 Y is scanned with the laser beam L, and thus an electrostatic latent image for yellow is formed thereon (exposure process). 
     Then, the surface of the photoconductor drum  1 Y reaches a position opposite the developing device  5 Y, where the electrostatic latent image is developed with toner into a yellow toner image (development process). 
     As the surface of the photoconductor drum  1 Y carrying the toner image reaches a position opposite a primary transfer roller  9 Y via the intermediate transfer belt  8 , the toner image on the photoconductor drum  1 Y is transferred onto the intermediate transfer belt  8  (primary transfer process). After the primary transfer process, a certain amount of untransferred toner remains on the photoconductor drum  1 Y. 
     When the surface of the photoconductor drum  1 Y reaches a position opposite the cleaning device  2 Y, a cleaning blade  2   a  of the cleaning device  2 Y mechanically collects the untransferred toner on the photoconductor drum  1 Y (cleaning process). 
     Subsequently, the surface of the photoconductor drum  1 Y reaches a position opposite a discharge device, and the discharge device removes any residual electric potential from the photoconductor drum  1 Y (discharging process) to complete a sequence of image forming processes performed on the photoconductor drum  1 Y. 
     The above-described image forming processes are performed in the image forming units  6 M,  6 C, and  6 K similarly to the yellow image forming unit  6 Y. That is, the exposure device  7  disposed below the image forming units  6 M,  6 C, and  6 K irradiates photoconductor drums  1 M,  1 C, and  1 K of the image forming units  6 M,  6 C, and  6 K with the laser beams L based on image data. 
     Then, the toner images formed on the photoconductor drums  1 Y,  1 M,  1 C, and  1 K through the development process are transferred therefrom and superimposed on the intermediate transfer belt  8 . Thus, a multicolor toner image is formed on the intermediate transfer belt  8 . 
     With reference to  FIG. 1 , it can be seen that the intermediate transfer unit  15  includes the intermediate transfer belt  8 , four primary transfer rollers  9 Y,  9 M,  9 C, and  9 K, a secondary-transfer backup roller  12 , multiple tension rollers, and a belt cleaning device. The intermediate transfer belt  8  is stretched around and supported by the multiple rollers and is rotated in the direction indicated by arrow A 1  illustrated in  FIG. 1  as one of the multiple rollers that serves as a drive roller rotates (i.e., the secondary-transfer backup roller  12 ). 
     The four primary transfer rollers  9 Y,  9 M,  9 C, and  9 K are pressed against the corresponding photoconductor drums  1 Y,  1 M,  1 C, and  1 K, respectively, via the intermediate transfer belt  8  to form primary transfer nips. A primary-transfer bias opposite in polarity to that of the toner is applied to the primary transfer rollers  9 Y,  9 M,  9 C, and  9 K. 
     While rotating in the direction indicated by arrow A 1  in  FIG. 1 , the intermediate transfer belt  8  passes through the primary transfer nips between the photoconductor drums  1 Y,  1 M,  1 C, and  1 K and the respective four primary transfer rollers  9 Y,  9 M,  9 C, and  9 K. Then, the single-color toner images on the photoconductor drums  1 Y,  1 M,  1 C, and  1 K are primarily transferred to and superimposed on the intermediate transfer belt  8 , thereby forming the multicolor image. 
     Subsequently, the intermediate transfer belt  8  carrying the multicolor toner image reaches a position opposite a secondary transfer roller  19 . At this position, the secondary-transfer backup roller  12  and the secondary transfer roller  19  press against each other via the intermediate transfer belt  8 , thereby forming a secondary transfer nip. The multicolor toner image on the intermediate transfer belt  8  is transferred onto a sheet P such as a paper sheet transported to the secondary transfer nip (secondary transfer process). At that time, untransferred toner that is not transferred onto the sheet P remains on the surface of the intermediate transfer belt  8 . 
     The surface of the intermediate transfer belt  8  then reaches a position opposite the belt cleaning device, and the untransferred toner is collected from the intermediate transfer belt  8  to complete a series of image transfer processes performed on the intermediate transfer belt  8 . 
     The sheet P is transported from a sheet feeder  26  disposed in a lower portion of the image forming apparatus  100  to the secondary transfer nip via a feed roller  27  and a registration roller pair  28 . 
     Specifically, the sheet feeder  26  contains a stack of multiple sheets P such as paper sheets piled one on another. As the feed roller  27  rotates counterclockwise in  FIG. 1 , the feed roller  27  feeds a top sheet P from the stack in the sheet feeder  26  to a roller nip between the registration roller pair  28 . 
     The registration roller pair  28  stops rotating temporarily, stopping the sheet P with a leading edge of the sheet P nipped in the registration roller pair  28 . Then, the registration roller pair  28  rotates 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 belt  8 . Thus, the desired multicolor toner image is transferred onto the sheet P. 
     Subsequently, the sheet P, onto which the multicolor image is transferred at the secondary transfer nip, is transported to a fixing device  20 . In the fixing device  20 , a fixing belt 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 ejected by an output roller pair  29  outside the image forming apparatus  100 . The sheets P ejected by the output roller pair  29  are sequentially stacked as output images on a stack tray  30  to complete a sequence of image forming processes performed in the image forming apparatus  100 . 
     Next, a description is provided of the configuration and operation of the developing device  5 Y in further detail with reference to  FIG. 2 . 
     The developing device  5 Y includes a developing roller  51 Y disposed opposite the photoconductor drum  1 Y, a doctor blade  52 Y opposite the developing roller  51 Y, two conveying screws  55 Y disposed in developer-containing compartments  53 Y and  54 Y, and a toner concentration sensor  56 Y to detect concentration of toner in a developer G. The developing roller  51 Y includes stationary magnets therein, a sleeve that rotates around the magnets, and the like. The developer-containing compartments  53 Y and  54 Y contain the two-component developer G including carrier and toner. The developer-containing compartment  54 Y communicates, via an opening on an upper side thereof, with a downward toner passage  64 Y. 
     The developing device  5 Y operates as follows. 
     The sleeve of the developing roller  51 Y rotates in the direction indicated by arrow A 2  illustrated in  FIG. 2 . The developer G is carried on the developing roller  51 Y by a magnetic field generated by the magnets. As the sleeve rotates, the developer G moves along a circumference of the developing roller  51 Y. 
     The percentage (concentration) of toner in the developer G (ratio of toner to carrier) in the developing device  5 Y is constantly adjusted within a predetermined range. More specifically, the toner supply device  60 Y (see  FIG. 3 ) supplies toner from the toner container  32 Y to the developer-containing compartment  54 Y as the toner in the developing device  5 Y is consumed to maintain a constant concentration. The configuration and operation of the toner supply device  60 Y are described in detail later. 
     The two conveying screws  55 Y stir and mix the developer G with the toner added to the developer-containing compartment  54 Y while circulating the developer G (toner) in the developer-containing compartments  53 Y and  54 Y. In this case, the developer G moves in the direction perpendicular to the surface of the paper on which  FIG. 2  is drawn. The toner in developer G is triboelectrically charged by friction with the carrier and electrostatically attracted to the carrier. Then, the toner is carried on the developing roller  51 Y together with the carrier by magnetic force generated on the developing roller  51 Y. 
     The developer G carried on the developing roller  51 Y is transported in the direction indicated by arrow A 2  illustrated in  FIG. 2  to the doctor blade  52 Y. The amount of developer G on the developing roller  51 Y is adjusted by the doctor blade  52 Y, after which the developer G is transported to a development range opposite the photoconductor drum  1 Y. The toner in the developer G is attracted to the electrostatic latent image formed on the photoconductor drum  1 Y due to the effect of an electric field generated in the development range. As the sleeve rotates, the developer G remaining on the developing roller  51 Y reaches an upper part of the developer-containing compartment  53 Y and separates from the developing roller  51 Y. 
     Next, the toner supply devices  60 Y,  60 M,  60 C, and  60 K are described below in detail with reference to  FIGS. 3 and 4 . 
     As illustrated in  FIGS. 1 to 4 , the respective color toners in the toner containers  32 Y,  32 M,  32 C, and  32 K installed in the toner container mount  70  are supplied to the corresponding developing devices  5 Y,  5 M,  5 C, and  5 K by the toner supply devices  60 Y,  60 M,  60 C, and  60 K provided for the respective color toners according to the amount of toner consumed in the corresponding developing devices  5 Y,  5 M,  5 C, and  5 K. 
     It is to be noted that the four toner supply devices  60 Y,  60 M,  60 C, and  60 K have a similar structure, and the four toner containers  32 Y,  32 M,  32 C, and  32 K have a similar structure except for the color of toner used in the image forming processes. Therefore, the toner supply device  60 Y and the toner container  32 Y for yellow are described below as representatives, and descriptions of the toner supply devices  60 M,  60 C, and  60 K and the toner containers  32 M,  32 C, and  32 K for the other three colors are omitted. 
     When the toner container  32 Y is installed in the toner container mount  70  of the image forming apparatus  100  in the direction indicated by arrow Q as illustrated in  FIG. 4  (hereinafter, referred to as the “installation direction”), a shutter  34   d  (see  FIG. 3 ) of the toner container  32 Y is moved in conjunction with the installation of the toner container  32 Y, and a toner outlet W (see  FIG. 3 ) of the toner containers  32 Y is opened. Consequently, the toner outlet W of the toner container  32 Y communicates with a toner supply inlet  73   w  of the toner supply device  60 Y. Accordingly, toner contained in the toner container  32 Y is discharged from the toner outlet W, passes through the toner supply inlet  73   w , and then, is stored in a toner tank  61 Y of the toner supply device  60 Y. 
     With reference to  FIG. 3 , it can be seen that the toner container  32 Y is a substantially cylindrical toner bottle and includes a cap  34 Y and a cylindrical container body (bottle body)  33 Y formed together with a gear  33   c  (see  FIG. 7 ). The cap  34 Y is held by the toner container mount  70  so as not to rotate. The container body  33 Y is held so as to rotate relative to the cap  34 Y and driven to rotate by a driving unit  91  in the direction indicated by arrow A 3  illustrated in  FIG. 3 . The driving unit  91  includes a driving motor, a drive gear  81 , and the like. The container body  33 Y includes a helical rib  33   b  (see  FIG. 5 ) protruding inward from an inner circumferential face of the container body  33 Y. As the container body  33 Y rotates, the helical rib  33   b  transports toner in the toner container  32 Y (the container body  33 Y) in the longitudinal direction of the container body  33 Y (from the left to the right in  FIG. 3 ). As a result, the toner is discharged through the toner outlet W of the cap  34 Y. That is, the driving unit  91  rotates the container body  33 Y of the toner container  32 Y as required, thereby supplying the toner to the toner tank  61 Y. Note that the toner containers  32 Y,  32 M,  32 C, and  32 K are replaced with new ones when the respective service lives thereof have expired, that is, when almost all toner contained in the toner container  32  has been depleted. 
     With reference to  FIG. 3 , it can be seen that the toner supply device  60 Y includes the toner container mount  70  (see  FIG. 4 ), the toner tank  61 Y, a toner conveying screw  62 Y, a stirrer  65 Y, a toner end sensor  66 Y, and the driving unit  91 . 
     The toner tank  61 Y is disposed below the toner outlet W of the toner container  32 Y to store toner discharged through the toner outlet W of the toner container  32 Y. A bottom of the toner tank  61 Y is coupled to an upstream side of the toner conveying screw  62 Y in the direction in which the toner is transported. 
     The toner end sensor  66 Y is disposed on a side wall of the toner tank  61 Y at a predetermined height from the bottom and detects that the amount of toner stored in the toner tank  61 Y has fallen below a predetermined amount. For example, a piezoelectric sensor can be used as the toner end sensor  66 Y. When a controller  90  recognizes that the amount of toner stored in the toner tank  61 Y is less than the predetermined amount using the toner end sensor  66 Y, the controller  90  causes the driving unit  91  (including the drive gear  81 ) to rotate the container body  33 Y of the toner container  32 Y for a predetermined period, thereby supplying toner to the toner tank  61 Y. If the toner end sensor  66 Y continues to report “toner end” even when this operation is repeated for a predetermined number of times, the controller  90  recognizes that the toner container  32 Y is empty (toner depletion). Then, the controller  90  causes a control panel of the image forming apparatus  100  to prompt a user to replace the toner container  32 Y. 
     The stirrer  65 Y is disposed at the center of the toner tank  61 Y (near the toner end sensor  66 Y) to prevent agglomeration of the toner stored in the toner tank  61 Y. The stirrer  65 Y includes a shaft and a flexible member disposed on the shaft. The stirrer  65 Y rotates clockwise in  FIG. 3  to stir the toner in the toner tank  61 Y. The tip of the flexible member of the stirrer  65 Y slidingly contacts a surface where the toner end sensor  66 Y detects in rotation cycles. As a result, the toner does not adhere to the surface detected by the toner end sensor  66 Y, thereby preventing the detection accuracy from deteriorating. 
     A toner conveying screw  62 Y transports the toner stored in the toner tank  61 Y obliquely upward. Specifically, the toner conveying screw  62 Y transports the toner linearly from the bottom (the lowest point) of the toner tank  61 Y to a point above the developing device  5 Y. Then, the toner thus transported by the toner conveying screw  62 Y falls through the downward toner passage  64 Y (see  FIG. 2 ) and is supplied to the developer-containing compartment  54 Y in the developing device  5 Y. 
     With reference to  FIG. 4 , it can be seen that the toner container mount  70  includes a cap holder  73  to hold the cap  34 Y of the toner container  32 Y, a bottle holder (container body holder)  72  to hold the container body  33 Y of the toner container  32 Y, and an insertion entrance  71  through which the toner container  32 Y is installed. 
     With reference to  FIG. 1 , as a front cover of the image forming apparatus  100  (on the front side in the direction perpendicular to the surface of the paper on which  FIG. 1  is drawn) is opened, the insertion entrance  71  of the toner container mount  70  is exposed. The toner containers  32 Y,  32 M,  32 C, and  32 K are installed and removed from the front side of the image forming apparatus  100 , in the longitudinal direction of the toner containers  32 Y,  32 M,  32 C, and  32 K as the installation direction, with the longitudinal axis of the toner containers  32 Y,  32 M,  32 C, and  32 K kept horizontal. 
     Herein, the longitudinal length of the bottle holder  72  is almost equal to the longitudinal length of the container body  33 Y. The cap holder  73  is located on one side in the longitudinal direction (installation direction) of the bottle holder  72 . The insertion entrance  71  is located on the other, opposite side of the bottle holder  72  in the longitudinal direction (installation direction) of the bottle holder  72 , that is, the side away from the cap holder  73 . Accordingly, in the installation of the toner container  32 Y into the toner container mount  70 , the cap  34 Y passes through the insertion entrance  71 , slides on the bottle holder  72  over a certain distance, and is then attached to the cap holder  73 . 
     Next, the toner containers  32 Y,  32 M,  32 C, and  32 K are described in detail with reference to  FIGS. 5 to 12 . 
     As illustrated in  FIGS. 5 and 6 , the toner container  32 Y includes the cylindrical container body (bottle body)  33 Y and the cap (bottle cap)  34 Y into which the head of the container body  33 Y is inserted. With reference to  FIGS. 7 and 8 , it can be seen that the toner container  32 Y is disassembled into a stirring member  33   f , the shutter  34   d , a shutter seal  36 , a radiofrequency identification (RFID) tag  35 , a cover  37 , and the like, in addition to the container body  33 Y and the cap  34 Y. 
     As illustrated in  FIGS. 7 and 8 , the gear  33   c , which rotates together with the container body  33 Y, and an opening A are disposed at the head on one side of the cylindrical container body  33 Y in the longitudinal direction (horizontal direction in  FIGS. 9 and 10 ). The opening A is disposed at the head of the container body  33 Y, which is on a leading side when the toner container  32 Y is installed in the toner container mount  70 , and toner contained in the container body  33 Y is discharged through the opening A to a hollow space S inside the cap  34 Y as illustrated in  FIG. 9 . 
     The toner in the container body  33 Y is transported to the hollow space S of the cap  34 Y (i.e., the container body  33 Y is driven to rotate) so that the amount of toner in the cap  34 Y does not fall below a predetermined draft line (threshold). 
     The gear  33   c  meshes with the drive gear  81  provided in the toner container mount  70  of the image forming apparatus  100  to rotate the container body  33 Y around a center of rotation indicated by the alternate long and short dash line in  FIG. 9 . An axis of rotation of the container body  33 Y (hereinafter, referred to as the “rotation axis”) extends in the longitudinal direction of the container body  33 Y. 
     Specifically, the gear  33   c  surrounds the whole opening A, and a plurality of teeth radiates outward relative to the center of rotation of the container body  33 Y. A part of the gear  33   c  is exposed from a cut-out portion  34 Y 1  (see  FIG. 6 ) formed in the cap  34 Y, and the gear  33   c  meshes with the drive gear  81  of the image forming apparatus  100  located obliquely below the gear  33   c . The driving force is transmitted from the drive gear  81  to the gear  33   c , and the container body  33 Y rotates in the direction indicated by arrow A 3  in  FIG. 3 . In the present embodiment, the drive gear  81  and the gear  33   c  are spur gears. 
     With reference to  FIGS. 5 and 6 , it can be seen that a grip  33   d  for users to grasp the toner container  32 Y during installation and removal is provided on the other end of the container body  33 Y (on the upstream or rear end in the installation direction). The user installs the toner container  32 Y in the image forming apparatus  100  while grasping the grip  33   d . When installed into the image forming apparatus  100 , the toner container  32 Y is moved in the direction indicated by the arrow in  FIG. 5 . 
     Additionally, the helical rib  33   b  protruding inward is formed on the inner circumferential face of the container body  33 Y. In other words, a helical groove is formed on an outer circumferential face of the container body  33 Y when viewed from outside. The helical rib  33   b  is for discharging toner contained in the container body  33 Y through the opening A. As the container body  33 Y rotates around the rotation axis extending in the longitudinal direction of the container body  33 Y, the helical rib  33   b  transports the toner toward the opening A. 
     In the present embodiment, the container body  33 Y is made of, for example, polyethylene terephthalate (PET). The container body  33 Y can be produced together with the gear  33   c  and the grip  33   d  disposed on the outer circumferential face as a single piece by blow molding. 
     With reference to  FIGS. 7 and 8 , it can be seen that the toner container  32 Y in the present embodiment includes the stirring member  33   f  that rotates together with the container body  33 Y. The stirring member  33   f  fits into a bottle rim  33   a  (the opening A) of the container body  33 Y. 
     The stirring member  33   f  is provided with a pair of substantially rod-shaped blades  33   f   1  that extends toward the hollow space S in the cap  34 Y from the opening A of the container body  33 Y. The two blades  33   f   1  are disposed opposite each other in the circumferential direction. The rotation of the stirring member  33   f  (the blades  33   f   1 ) together with the bottle rim  33   a  (the opening A) of the container body  33 Y improves the ability to discharge toner from the opening A. 
     With reference to  FIGS. 7 and 8 , it can be seen that the bottle rim  33   a  of the container body  33 Y has a pawl portion  33   e  (see  FIG. 7 ) that is formed in a circumferential direction and engageable with the cap  34 Y. With this configuration, the container body  33 Y rotatably engages the cap  34 Y. Therefore, the gear  33   c  rotates relative to the cap  34 Y. 
     The inner diameter of the head of the container body  33 Y near the gear  33   c  is smaller than the inner diameter of the portion to store toner, where the helical rib  33   b  is formed. The head of the container body  33 Y includes a pump-up portion surrounded by the broken-line circles in  FIGS. 7 and 8  that gradually protrudes inward from the inner circumferential face. The toner transported toward the opening A by the helical rib  33   b  along with rotation of the container body  33 Y is pumped up by the pump-up portion surrounded by the broken-line circles in  FIGS. 7 and 8  to the portion of the head having the small inner diameter. Thereafter, the toner pumped up to the portion of the head having the small inner diameter is discharged from the opening A to the hollow space S of the cap  34 Y while being stirred by the stirring member  33   f.    
     With reference to  FIG. 7 , it can be seen that the shutter  34   d , the shutter seal  36 , the RFID tag  35 , and the cover  37  are attached to the cap  34 Y of the toner container  32 Y. 
     The bottle rim  33   a  (the opening A) of the container body  33 Y is inserted into the cap  34 Y. The toner outlet W is disposed at the bottom of the cap  34 Y. Toner discharged from the opening A of the container body  33 Y is discharged outside the toner container  32 Y and falls vertically downward through the toner outlet W. The shutter  34   d  (see  FIG. 6 ) is held and slidably movable at the bottom of the cap  34 Y to open and close the toner outlet W. Specifically, the shutter  34   d  opens the toner outlet W by a relative movement in the longitudinal direction from the cap  34 Y toward the container body  33 Y (movement in the direction indicated by the arrow in  FIG. 6 ). The shutter  34   d  closes the toner outlet W by a relative movement in the longitudinal direction from the container body  33 Y toward the cap  34 Y (movement in the direction opposite to the direction indicated by the arrow in  FIG. 6 ). The shutter  34   d  moves to open and close the toner outlet W in conjunction with movement of the toner container  32 Y that is installed in and removed from the toner container mount  70  of the image forming apparatus  100 . 
     The cap  34 Y having such a configuration communicates with the container body  33 Y via the opening A, and the toner discharged from the opening A is discharged through the toner outlet W as indicated by broken-line arrow A 4  illustrated in  FIG. 3 . 
     In the present embodiment, the substantially cylindrical hollow space S (see  FIG. 9 ) extending in the longitudinal direction is formed inside the cap  34 Y. In addition, in the cap  34 Y, a columnar downward path, through which toner falls, having a predetermined cross-sectional area extends from a lower circumference of the substantially cylindrical hollow space S toward the toner outlet W. With this configuration, toner discharged from the opening A of the container body  33 Y to the hollow space S of the cap  34 Y falls through the columnar downward path and is smoothly discharged outside the toner container  32 Y (to the toner tank  61 Y) through the toner outlet W. 
     With reference to  FIG. 7 , an annular cap seal adheres to an inner face of the cap  34 Y facing the bottle rim  33   a  surrounding the opening A of the container body  33 Y. The cap seal seals the gap between the container body  33 Y and the cap  34 Y around the opening A, and is made of, for example in the present embodiment, an elastic material (foam resin material) such as foamed polyurethane. 
     The RFID tag  35  is provided on an end face of the cap  34 Y, and the cover  37  covers the RFID tag  35 . The RFID tag  35  stores data such as the production number of the toner container  32 Y and the number of recycles, toner volume, lot number, and color. The data in the RFID tag  35  is written and read by the image forming apparatus  100 . 
     The configuration and operation of the toner container  32 Y,  32 M,  32 C, and  32 K according to the present embodiment are described below. 
     As illustrates in  FIGS. 9 and 10 , a sheet member  34   f  is attached inside the cap  34 Y of the toner container  32 Y. 
     In the present embodiment, the sheet member  34   f  is made of a flexible material such as a plastic sheet having a thickness of about 0.01 to 0.15 mm. The sheet member  34   f  includes a first elastic-deformation portion  34   f   1  located near the toner outlet W and a second elastic-deformation portion  34   f   2  located in the container body  33 Y and near the opening A. The first and second elastic-deformation portions  34   f   1  and  34   f   2  are elastically deformable. 
     Specifically, the sheet member  34   f  is supported by a stationary shaft  34   g  extending in the direction of rotation axis (longitudinal direction) of the container body  33 Y. The root of the stationary shaft  34   g  is firmly secured to the face of the cap  34 Y facing the opening A of the container body  33 Y so that the tip of the stationary shaft  34   g  enters the interior of the container body  33 Y. In the present embodiment, the sheet member  34   f  is sandwiched and secured between the milling surface of the stationary shaft  34   g  and a plate by screwing or the like. 
     However, the manner to secure the sheet member  34   f  is not limited to the above-described embodiments, but various types of configurations can be used. 
     The first elastic-deformation portion  34   f   1  has a plurality of teeth arranged in a comb shape in the longitudinal direction of the container body  33 Y, facing the toner outlet W (the downward path). In particular, the plurality of teeth of the first elastic-deformation portion  34   f   1  are arranged in a row with a gap in the longitudinal direction. That is, the teeth of the first elastic-deformation portion  34   f   1  face downward, and the gap (concave notch) N is provided between the adjacent teeth. 
     On the other hand, the second elastic-deformation portion  34   f   2  has a plurality of teeth arranged in a comb shape in the longitudinal direction, contacting an upper portion of the inner wall (inner circumferential face) of the container body  33 Y. In particular, the plurality of teeth of the second elastic-deformation portion  34   f   2  is arranged in a row without a gap in the longitudinal direction. That is, the teeth of the second elastic-deformation portion  34   f   2  face upward and are provided with cuts such that the adjacent teeth contact each other. 
     Even when the container body  33 Y is driven to rotate during toner supply in the image forming apparatus  100  (the toner supply device  60 Y), the sheet member  34   f  is supported in a non-rotating state by the toner supply device  60 Y together with the cap  34 Y. 
     With reference to  FIG. 11 , it can be seen that, as the container body  33 Y (the stirring member  33   f ) rotates clockwise as indicated by the arrow in  FIG. 11 , the first elastic-deformation portion  34   f   1  strikes the stirring member  33   f  fitted into the opening A (the bottle rim  33   a ) of the container body  33 Y, thereby repeating deformation in rotation cycle. 
     Specifically, the first elastic-deformation portion  34   f   1  is provided so as to be able to interfere with the blade  33   f   1  of the stirring member  33   f  and is disposed directly above the toner outlet W. The blades  33   f   1  of the stirring member  33   f  rotate to the position indicated by the broken-line circles in  FIG. 11  and interfere with the first elastic-deformation portion  34   f   1 , causing the first elastic-deformation portion  34   f   1  to bend leftward. After that, as the stirring member  33   f  further rotates and the interference of the blade  33   f   1  with the first elastic-deformation portion  34   f   1  is released, the elasticity of the first elastic-deformation portion  34   f   1  urges the first elastic-deformation portion  34   f   1  rightward so that the first elastic-deformation portion  34   f   1  is flipped to the right, and eventually returns to the original position illustrated by the solid line. By repeating such swinging of the first elastic-deformation portion  34   f   1  as indicated by the double-headed arrow in  FIG. 11 , toner near (above) the toner outlet W is constantly stirred and loosened, thereby preventing the toner from agglomerating and clogging the opening. 
     In particular, in the present embodiment, the plurality of teeth in the first elastic-deformation portion  34   f   1  are arranged in a row with the gap in the longitudinal direction, thereby facilitating flow of toner at the bottom of the hollow space S in the cap  34 Y as compared with the case in which the teeth are arranged in a row without the gap. 
     In the present embodiment, the first elastic-deformation portion  34   f   1  strikes the stirring member  33   f  to repeat the elastic deformation. Alternatively, the first elastic-deformation portion  34   f   1  can directly strike the container body  33 Y (e.g., a projection disposed on the bottle rim  33   a ) to repeat the elastic deformation. 
     On the other hand, with reference to  FIG. 12 , it can be seen that the second elastic-deformation portion  34   f   2  slidingly contacts the upper portion of the inner wall near the opening A of the container body  33 Y along with rotation of the container body  33 Y in the direction indicated by the arrow in  FIG. 12 . 
     Specifically, the second elastic-deformation portion  34   f   2  has a length sufficient to slidingly contact the upper portion of the inner circumferential face near the opening A surrounded by the broken-line circle in  FIG. 12 . As the container body  33 Y rotates, the edge of the second elastic-deformation portion  34   f   2  slidingly contacts the upper portion of the inner wall of the container body  33 Y. The upper portion of the inner wall is constantly replaced with the surface in a different place of the inner wall along with rotation of the container body  33 Y. At that time, due to the elasticity of the second elastic-deformation portion  34   f   2 , the second elastic-deformation portion  34   f   2  maintains the deformed shape illustrated in  FIG. 12  or vibrates, thereby scraping off toner adhering to the inner wall at the upper portion. Toner is likely to accumulate near the opening A from top to bottom. In particular, the toner is likely to adhere to the upper portion of the inner wall. If the toner adheres to the inner wall, the amount of toner remaining in the toner container  32 Y increases at the time of toner depletion. Further, if the toner that has agglomerated after adhering to the inner wall is separated from the inner wall and enters the toner outlet W, the toner outlet W may be blocked by the agglomerated toner. In the present embodiment, since the toner adhering to the upper portion of the inner wall is constantly scraped off by the second elastic-deformation portion  34   f   2 , such problems as described above hardly occur. 
     In particular, in the present embodiment, the plurality of teeth in the second elastic-deformation portion  34   f   2  are arranged in a row without a gap in the longitudinal direction. As a result, toner adhering to the periphery of the helical rib  33   b  on the inner wall can be scraped off cleanly as compared with the case in which the plurality of teeth in the second elastic-deformation portion  34   f   2  are arranged in a row with a gap. 
     As described above, in the present embodiment, the sheet member  34   f  including the first and second elastic-deformation portions  34   f   1  and  34   f   2  loosens toner near the toner outlet W and scraps off toner adhering to the inner wall in the container body  33 Y and near the opening A, thereby preventing the toner outlet W from being blocked by the agglomerated toner. Therefore, toner can be satisfactorily discharged from the toner container  32 Y, and the defective toner supply to the developing device  5 Y is less likely to occur. 
     As described above, the toner container  32 Y includes the container body  33 Y having the opening A disposed at the head of the container body  33 Y, the cap  34 Y into which the head of the container body  33 Y is inserted, and the sheet member  34   f  attached inside the cap  34 Y. The container body  33 Y is cylindrical and rotates around the rotation axis extending in the longitudinal direction of the container body  33 Y to transport toner contained in the container body  33 Y toward the opening A. The cap  34 Y has the toner outlet W through which the toner discharged from the opening A is discharged outside the toner container  32 Y. The sheet member  34   f  include the first elastic-deformation portion  34   f   1  that is elastically deformable and located near the toner outlet W, and the second elastic-deformation portion  34   f   2  that is elastically deformable and located in the container body  33 Y and near the opening A. 
     This configuration prevents the toner outlet W from being blocked by agglomerated toner. 
     As a result, according to the present disclosure, a toner container, a toner supply device, and an image forming apparatus can be provided that prevent the agglomerated toner from blocking the toner outlet. 
     It is to be noted that, although the toner containers  32 Y,  32 M,  32 C, and  32 K contain only toner in the above-described embodiments, alternatively, toner containers may contain a two-component developer including toner and carrier to be used in image forming apparatuses in which the two-component developer is supplied to the developing device. 
     In such configurations, effects similar to those described above are also attained. 
     Further, in the present embodiment, a part or all of the image forming units  6 Y,  6 M,  6 C, and  6 K may be a process cartridge. In such configurations, effects similar to those described above are also attained. 
     It is to be noted that the term “process cartridge” used in the present disclosure means a removable unit including an image bearer and at least one of a charging device to charge the image bearer, a developing device to develop latent images on the image bearer, and a cleaning device to clean the image bearer that are united together, and is designed to be removably installed as a united part in the image forming apparatus. 
     The above-described embodiments are illustrative and do not limit the present disclosure. Thus, numerous additional modifications and variations are possible in light of the above teachings. It is therefore to be understood that within the scope of the present disclosure, the present disclosure may be practiced otherwise than as specifically described herein. The number, position, and shape of the components described above are not limited to those embodiments described above. Desirable number, position, and shape can be determined to perform the present disclosure.