Patent Publication Number: US-7596338-B2

Title: Toner container, toner feed device and image forming apparatus

Description:
This Nonprovisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2006-192516 filed in Japan on 13 Jul. 2006, the entire contents of which are hereby incorporated by reference. 
   BACKGROUND 
   Technical Field 
   An example embodiment of the present invention relates to a toner container for storing toner used for an image forming apparatus such as a copier, printer, facsimile machine and the like as well as to a toner feed device to which the toner container is removably attached and an image forming apparatus equipped with the toner feed device. The example embodiment particularly relates to a supporting structure for supporting the toner container. 
   In general, in an image forming apparatus such as a copier, printer, facsimile machine and a multifunctional machine at least including two functions of these, its output is produced by forming an electrostatic latent image on a photoreceptor, developing the electrostatic image on the photoreceptor with a developer that is fed from a developing unit to the photoreceptor to form a developer image on the photoreceptor, transferring the developer image from the photoreceptor to recording paper and heating and pressing the recording paper to fix the developer image to the recording paper. 
   In the developing unit, for example a dual component developer composed of a mixture of a toner and a magnetic carrier is agitated so as to tribo-electrify the toner, and the thus agitated dual-component developer is caused to adhere to a rotating developing roller so as to convey and supply the dual-component developer to the development area between the developing roller and photoreceptor, to thereby develop the electrostatic latent image on the photoreceptor with the toner from the dual-component developer. The developer roller is composed of a cylindrical sleeve and magnets arranged in the sleeve. The developer roller, as it is rotating its sleeve and attracting the dual-component developer to the sleeve surface by the magnetic field from the magnets in the sleeve, conveys and supplies the dual-component developer from the sleeve to the photoreceptor. 
   Further, since, in the developing unit, toner is consumed from the dual-component developer as electrostatic latent images on the photoreceptor are developed, toner has to be successively supplied by means of a toner feed device as the developer is consumed. This toner feed device includes an intermediate hopper (toner supply hopper) for temporarily storing the toner to be fed to the developing unit and supplying the necessary amount of toner to the developing unit and a toner container for storing toner mounted to the intermediate hopper. Provided in the portion where the toner container is mounted to the intermediate hopper is a mounting mechanism for allowing the toner container to be removably mounted to the intermediate hopper. This mounting mechanism is formed with a feed path for connecting the toner discharge port of the toner container with the intermediate hopper. In this way, toner is supplied from the toner feed device including a toner container such as a toner cartridge, toner bottle or the like, to the developing unit, and when almost all the toner in the toner container is used up, the toner container is replaced with a new one as appropriate by the user. 
   One configuration of such a toner container is disclosed in, for example, Japanese Patent Application Laid-open 2004-333854. This container is constructed such that its container body has projected pieces formed at its one end face with respect to the axial direction thereof, and is mounted to an image forming apparatus with the projected pieces engaged with a main-body side coupler so that a rotational drive force about the axis can be transferred to the container. The container body also has a refill port for charging the developer, formed at the same end face with respect to the axial direction and covered with a removable cap member so that the cap member is covered by the main body-side coupler when the projected pieces are coupled with the main body-side coupler. This toner container has a toner discharge aperture at the approximate center of the container body, and the approximately central portion of the container body including the portion where the toner discharge aperture is formed is supported by an approximately cylindrical supporting structure. This supporting structure has a toner feed aperture formed at the position corresponding to the toner discharge aperture of the container body. This toner feed aperture is provided with a shutter element that can open and close the opening in the lengthwise direction of the toner container. As the thus constructed toner container is rotated by a drive source provided for the main body side, the sealing sheet attached to the toner discharge port for preventing toner leakage is removed so that toner in the toner container is discharged through the toner discharge port, passes through the toner feed aperture of the supporting structure to be supplied to the intermediate hopper. 
   However, there is a risk that the container body supported by the supporting structure is erroneously rotated by unexpected impacts, vibrations and the like during shipment and transportation of the toner container. That is, this configuration entails the problem that the sealing sheet that has been attached to the toner discharge port comes off and the user&#39;s hands and clothes and the like are dirtied by leakage and scatter of toner in the toner container before the toner container is mounted to the toner feed device. 
   SUMMARY 
   An example embodiment has been devised in view of the above problem entailed with the conventional toner container and toner feed device, it is therefore an object of the example embodiment to provide a new and improved toner container, toner feed device and image forming apparatus, with which the toner container can be prevented from rotating before it is mounted to the toner feed device and used therein. 
   In order to achieve the above object, one aspect of the example embodiment provides a toner container that is removably attached to a toner feed device for feeding toner to a developing unit provided for an image forming apparatus, comprising: 
   a container body including a toner storing portion filled with toner, and a toner discharge aperture arranged in a toner feed recess formed on the outer peripheral surface of the toner storing portion for discharging toner from the toner storing portion by rotationally driving the toner storing portion about the axis thereof as a rotary axis; and 
   a supporting structure, which supports the container body in a rotatable manner by enclosing the outer peripheral surface along the rotational direction of the container body so as to include the area where the toner feed recess is formed, and has a toner feed aperture for feeding the toner discharged from the toner discharge aperture into the toner feed recess, to the outside, characterized in that 
   the supporting structure includes a shutter opening and closing mechanism having an approximately plate-like shutter element that is movable along a fixed direction for opening and closing the toner feed aperture; 
   the container body is applied with a sealing element for sealing the toner discharge aperture; 
   the sealing element is engaged with the supporting structure at one end opposite to the other end thereof which seals the toner discharge aperture when the container body is held by the supporting structure; and, 
   the side surface of the container body against which the shutter opening and closing mechanism provided for the supporting structure abuts is formed with an engaging projection for engaging the shutter opening and closing mechanism when the shutter element confines the toner feed aperture. 
   Since, with the above configuration, the engaging projection formed on the container body is engaged with the shutter opening and closing mechanism that is closing the toner feed aperture, it is possible to prevent the container body supported by the supporting structure from being erroneously rotated by unexpected impacts, vibrations and the like during shipment and transportation of the toner container, hence it is possible to prevent the sealing element adhering to the toner discharge port of the container body from coming off and hence prevent toner leakage and scattering inside the toner container. 
   Also in the above example embodiment, the sealing element may be formed of a material having air permeability and hygroscopicity. 
   With this configuration, it is possible to eliminate the difference in pressure between the interior and exterior of the container body of the toner container and also to prevent the toner inside the container body from being exposed to moisture. As a result, it is possible to prevent toner from scattering due to pressure difference between the interior and exterior of the container when toner is discharged from the container body of the toner container and also to maintain the toner inside the container in a constant dried condition, hence keep the quality of the toner inside the container. 
   Another aspect of the example embodiment in order to solve the above problem provides a toner feed device comprising: a toner container including a container body filled with toner and a supporting structure for supporting the container body in a rotatable manner; and an intermediate hopper which has the toner container attached thereto, temporarily stores the toner discharged from the toner feed aperture of the toner container as the container body is rotationally driven about the axis thereof as a rotational axis and supplies the toner to a developing unit provided for an image forming apparatus, wherein any one of the above toner containers is removably mounted. 
   Since the engaging projection formed on the container body is engaged with the shutter opening and closing mechanism that is closing the toner feed aperture, this configuration makes it possible to prevent the container body supported by the supporting structure from being erroneously rotated by unexpected impacts, vibrations and the like during shipment and transportation of the toner container, hence enables easy mounting without causing any toner leakage when the toner container is mounted to the toner feed device, thus contributing to improvement in workability and maintenance performance. 
   In the above aspect, it is possible to adapt a rotational load to be applied to the container body when the container body is rotated to supply toner by releasing the shutter element, retracting the engaging projection from the shutter opening and closing mechanism. 
   With this configuration, it is possible to prevent the container body from being easily rotated by external force such as human strength or the like even when the shutter opening and closing mechanism is broken or in any other anomaly condition. As a result it is possible to prevent the sealing element that is being applied to the toner discharge aperture of the container body from peeling off before the toner container is used, thus improving the toner container in maintenance performance. 
   As described heretofore, according to the example embodiment, since it is possible to prevent the container body of the toner container from being rotated before the toner container is set to the toner feed device and used, it is possible to prevent toner leakage, scattering and the like inside the toner container due to removal of the sealing element being adhered to the toner discharge port of the container body as a result of unexpected impacts, vibrations and the like. Accordingly, this configuration facilitates the user to handle the toner container without causing toner leakage when the user handles the toner container alone such as during hand carriage. As a result, improvement in workability and maintenance performance can be expected without dirtying the user, image forming apparatus etc., with toner spilling out of the toner container. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an illustrative view showing an overall configuration of the first example embodiment of an image forming apparatus in which a toner container according to the present example embodiment is used; 
       FIG. 2  is a partial detailed view showing the configuration of the apparatus body of the image forming apparatus in the example embodiment; 
       FIG. 3  is an illustrative view showing the configuration of paper feed paths in the image forming apparatus according to the same example embodiment; 
       FIG. 4  is a partial detailed view showing the configuration of branched paper feed paths for the paper feed paths and branch guides for connection therebetween shown in  FIG. 3 ; 
       FIG. 5  is an overall sectional side view showing a developing unit and toner feed device provided for the image forming apparatus according to the same example embodiment; 
       FIG. 6  is an overall front view showing the configuration of the toner feed device in the same example embodiment, when viewed from the P-direction in  FIG. 5 ; 
       FIG. 7  is a front view showing a toner container in the same example embodiment; 
       FIG. 8  is a front view showing how the toner container of the same example embodiment is assembled; 
       FIG. 9  is a side view, viewed in the Q direction in  FIG. 8 ; 
       FIG. 10  is a rear side view of the container body shown in  FIG. 8 ; 
       FIG. 11A  is a perspective view showing the end part of the container body in the same example embodiment, at the side coupled to the main body-side coupler, and  FIG. 11B  is a front view of the same end part; 
       FIG. 12  is a partial perspective view for explaining the configuration around a toner discharge aperture of the container body in the same example embodiment; 
       FIG. 13  is a partial perspective view, viewed from the rear side of the container body shown in  FIG. 12 ; 
       FIG. 14A  is a perspective view showing a configuration of a first supporting member of a supporting structure in the same example embodiment, and  FIG. 14B  is a perspective view showing a configuration of a second supporting member of the supporting structure in the same example embodiment; 
       FIG. 15A  is a side view showing the first supporting member of the supporting structure of the toner container in the same example embodiment, and  FIG. 15B  is a plan view showing the first supporting member, viewed from its bottom side; 
       FIG. 16A  is a perspective view showing a shutter element provided for a shutter mechanism in the same example embodiment, viewed from its front,  FIG. 16B  is a perspective view showing the same shutter element, viewed from its rear, and  FIG. 16C  is an illustrative view showing a state in which the shutter element is attached to the first supporting member; 
       FIG. 17  is a partial perspective view showing essential parts in the mount surface of an intermediate hopper on which the toner container is placed in the same example embodiment; 
       FIG. 18A  is a plan view showing the first supporting member, viewed from the bottom side when the toner container of the same example embodiment is set on the intermediate hopper and starts to be slid in the S-direction after the anti-slide function is released, and  FIG. 18B  is a side view showing the vicinity of a hook of the first supporting member when the toner container of the same example embodiment is set on the intermediate hopper and is being slid in the S-direction after the anti-slide function is released; 
       FIG. 19A  is a plan view showing the first supporting member, viewed from the bottom side when the toner container of the same embodiment is set on the intermediate hopper and slid in the S-direction to open a shutter element after the anti-slide function is released, and  FIG. 19B  is a side view showing the vicinity of the hook of the first supporting member when the toner container of the same example embodiment is set on the intermediate hopper and is slid in the S-direction to open the shutter element after the anti-slide function is released; 
       FIG. 20A  is an illustrative view, viewed from the width direction of the toner container, for explaining how the shutter opening and closing mechanism prevents the container body from being rotated when the container body of the toner container of the same example embodiment is supported by the supporting structure, and  FIG. 20B  is an illustrative view, viewed from the width direction of the toner container, for explaining the operational state where the toner container is rotated in the reverse direction (in the IR-direction) of the forward direction (in the R-direction) for feeding toner when the container body of the toner container of the same example embodiment is supported by the supporting structure; and, 
       FIG. 21A  is an illustrative view, viewed from the width direction of the toner container, for explaining the operational state where the toner container is rotated in the IR-direction when the shutter opening and closing mechanism provided for the toner container of the same example embodiment is broken or damaged and hence the anti-rotation mechanism of the container body by the shutter opening and closing mechanism does not function, and  FIG. 21B  is an illustrative view, viewed from the width direction of the toner container, for explaining the operational state where the shutter opening and closing mechanism provided for the toner container of the same example embodiment is released and the container body is rotated in the R-direction to peel off the enclosing seal. 
   

   DESCRIPTION OF THE PREFERRED EXAMPLE EMBODIMENTS 
   A preferred example embodiment will hereinafter be described in detail with reference to the accompanying drawings. Here in this specification and drawings, the components having essentially the same functions are allotted with the same reference numerals so that repeated description will be omitted. 
   The First Example Embodiment 
   To being with, the configuration of the first example embodiment of an image forming apparatus in which a example embodiment toner container is used will be described with reference to the drawings.  FIG. 1  is an illustrative view showing an overall configuration of the first example embodiment of an image forming apparatus in which a toner container according to the present example embodiment is used, and  FIG. 2  is a partial detailed view showing the configuration of the apparatus body of the same image forming apparatus. 
   An image forming apparatus  1 A in which a toner container according to the present example embodiment is used is an image forming apparatus that forms and outputs a monochrome image of image data that was captured by a scanner or the like or image data that was transferred from without, on a predetermined sheet of recording material (to be referred to hereinbelow as paper) as a recording medium, by electrophotography. This image forming apparatus  1 A includes a paper feed tray  8  which can stack multiple sheets of paper P thereon; a paper conveying portion  59  for conveying paper P fed from this paper feed tray  8  to an image forming portion  14 ; and a paper conveyor system  7  for conveying the paper P with an unfixed toner image printed thereon by image forming portion  14  to a fixing unit  6  where the unfixed toner is fused and fixed onto the paper. The image forming apparatus, based on the conveying speeds of paper P corresponding to a multiple number of preset printout processing modes, can select and control the conveying speed of paper P in accordance with a print request and feed paper P from paper feed tray to a paper output tray  9 . 
   Image forming apparatus  1 A is essentially composed of, as shown in  FIG. 1 , an apparatus body  1 A 1  including a light exposure unit  1 , a developing unit  2 , a toner feed device  30 , a photoreceptor drum  3 , a charger  4 , a charge erasing device  41 , a cleaner unit  5 , a fixing unit  6 , paper conveyor system  7 , a paper feed paths  7   a , paper feed tray  8 , paper output tray  9 , a transfer device  10  and the like, and an automatic document processor  1 A 2 . 
   Formed on the top surface of apparatus body  1 A 1  is an original placement table  21  made of transparent glass on which a document is placed. Automatic document processor  1 A 2  is arranged on top of this original placement table  21  so that it can pivotally open upwards while a scanner portion  22  as a document reader for reading image information of originals is laid out under this original placement table  21 . 
   Arranged below scanner portion  22  are light exposure unit  1 , developing unit  2 , photoreceptor drum  3 , charger  4 , charge erasing device  41 , cleaner unit  5 , fixing unit  6 , paper conveyor system  7 , paper feed paths  7   a  ( 7   a   1  to  7   a   8 :  FIGS. 3 and 4 ), paper output tray  9  and transfer device  10 . Further, paper feed tray  8  that accommodates paper P is arranged under these. 
   Light exposure unit  1  provides a function of emitting laser beam in accordance with the image data output from an unillustrated image processor to irradiate the photoreceptor drum  3  surface that has been uniformly charged by charger  4  so as to write and form an electrostatic latent image corresponding to the image data on the photoreceptor drum  3  surface. This light exposure unit  1  is arranged directly under scanner portion  22  and above photoreceptor drum  3 , and includes laser scanning units (LSUs)  13   a  and  13   b  each having a laser emitter  11  and a reflection mirror  12 . In the present example embodiment, in order to achieve high-speed printing operation, a method for alleviating the rush of irradiation timings by using a multiple number of laser beams, namely a two-beam method, is adopted. Here, in the present example embodiment laser scanning units (LSUs)  13   a  and  13   b  are used for light exposure unit  1 , but an array of light emitting elements, e.g., an EL or LED writing head may also be used. 
   Photoreceptor drum  3  has an approximately cylindrical shape, is arranged under light exposure unit  1  and is controlled so as to rotate in a predetermined direction (in the direction of arrow A in the drawing) by an unillustrated drive means and control means. Arranged starting from the position at which image transfer ends downstream in the rotational direction of the photoreceptor drum along the peripheral surface of this photoreceptor drum  3  are, as shown in  FIG. 2 , a paper separation claw  31 , cleaner unit  5 , charger  4  as an electric field generator, developing unit  2  and charge erasing device  41  in the order mentioned. 
   Paper separation claw  31  is disposed so as to be moved into and out of contact with the outer peripheral surface of photoreceptor drum  3  by means of a solenoid  32 . When this paper separation claw  31  is put in abutment with the outer peripheral surface of photoreceptor drum  3 , it functions to peel off the paper P that has adhered to the photoreceptor drum  3  surface during the unfixed toner image on photoreceptor drum  3  being transferred to the paper. Here, as a drive means for paper separation claw  31 , a drive motor or the like may be used instead of solenoid  32 , or any other drive means may be also selected. 
   Developing unit  2  visualizes the electrostatic latent image formed on photoreceptor drum  3  with black toner, and is arranged at approximately the same level at the side (on the right side in the drawing) of photoreceptor drum  3  downstream of charger  4  with respect to the rotational direction of the photoreceptor drum (in the direction of arrow A in the drawing). A registration roller  15  is disposed under this developing unit  2  on the upstream side with respect to the recording medium feed direction. 
   Toner feed device  30  temporarily holds the toner discharged from a toner container  300  filled with toner, in an intermediate hopper  33  and then supplies it to developing unit  2 . This toner feed device is arranged adjacent to developing unit  2 . Details of toner feed device  30  will be described later. 
   Registration roller  15  is operated and controlled by an unillustrated drive means and control means so as to convey the paper P delivered from paper feed tray  8  into and between photoreceptor drum  3  and a transfer belt  103  whilst making the leading end of the paper P register with the toner image on the photoreceptor drum  3 . 
   Charger  4  is a charging means for uniformly charging the photoreceptor drum  3  surface at a predetermined potential, and is arranged over photoreceptor drum  3  and close to the outer peripheral surface thereof. Here, a discharge type charger  4  is used in the present example embodiment, but a contact roller type or a brush type may be used instead. 
   Charge erasing device  41  is a pre-transfer erasing means for lowering the surface potential of the photoreceptor drum  3  in order to facilitate the toner image formed on the photoreceptor drum  3  surface to transfer to paper P, and is laid out on the downstream side of developing unit  2  with respect to the photoreceptor drum&#39;s direction of rotation and under photoreceptor drum  3  and close to the outer peripheral surface of the same. Though in the present example embodiment, charge erasing device  41  is configured using a charge erasing electrode, a charge erasing lamp or any other method can be used instead of the charge erasing electrode. 
   Cleaner unit  5  removes and collects the toner left on the surface of photoreceptor drum  3  after development and image transfer, and is disposed at approximately the same level at the side of photoreceptor drum  3  (on the left side in the drawing), on the approximately opposite side across photoreceptor drum  3  from developing unit  2 . 
   As described above, the visualized electrostatic image on photoreceptor drum  3  is transferred to the paper P being conveyed as transfer device  10  applies an electric field having an opposite polarity to that of the electric charge of the electrostatic image. For example, when the electrostatic image bears negative (−) charge, the applied polarity of transfer device  10  should be positive (+). 
   Transfer device  10  is provided as a transfer belt unit form in which a transfer belt  103  having a predetermined resistivity (ranging from 1×10 9  to 1×10 13 Ω·cm in the example embodiment) is wound and tensioned on a drive roller  101 , a driven roller  102  and other rollers, and is disposed under photoreceptor drum  3  with the transfer belt  103  surface put in contact with part of the outer peripheral surface of photoreceptor drum  3 . This transfer belt  103  conveys paper P while pressing the paper against photoreceptor drum  3 . An elastic conductive roller  105  having a conductivity different from that of drive roller  101  and driven roller  102  and capable of applying a transfer electric field is laid out at a contact point  104  ( FIG. 2 ) where transfer belt  103  comes into contact with photoreceptor drum  3 . 
   Elastic conductive roller  105  is composed of a soft material such as elastic rubber, foamed resin etc. Since this elasticity of elastic conductive roller  105  permits photoreceptor drum  3  and transfer belt  103  to come into, not line contact, but area contact of a predetermined width (called a transfer nip) with each other, it is possible to improve the efficiency of transfer to the paper P being conveyed. 
   Further, a charge erasing roller  106  ( FIG. 2 ) for erasing the electric field that has been applied to the paper P being conveyed through the transfer area so as to achieve smooth conveyance of the paper to the subsequent stage is disposed on the interior side of transfer belt  103 , on the downstream side, with respect to the direction of paper conveyance, of the transfer area of transfer belt  103 . 
   As shown in  FIG. 2 , transfer device  10  also includes a cleaning unit  107  for removing dirt due to leftover toner on transfer belt  103  and a plurality of charge erasing devices  108  for erasing electricity on transfer belt  103 . Erasure of charge by erasing devices  108  may be performed by grounding via the apparatus or by positively applying charge of a polarity opposite to that of the transfer field. 
   The paper P with the static image (unfixed toner) transferred thereon by transfer device  10  is conveyed to fixing unit  6 , where it is pressed and heated so as to fuse the unfixed toner and fix it to the paper P. Fixing unit  6  includes a heat roller  6   a  and a pressing roller  6   b  as shown in  FIG. 2  and fuses and fixes the toner image transferred on paper P by rotating heat roller  6   a  so as to convey the paper held between heat roller  6   a  and pressing roller  6   b  through the nip between heat roller  6   a  and pressing roller  6   b . Arranged on the downstream side of fixing unit  6  with respect to the direction of paper conveyance is a conveyance roller  16  for conveying paper P. 
   Heat roller  6   a  has a sheet separation claw  611 , a thermistor  612  as a roller surface temperature detector and a roller surface cleaning member  613 , all arranged on the outer periphery thereof and a heat source  614  for heating the heat roller surface at a predetermined temperature (set fixing temperature: approximately 160 to 200 deg. C.) provided in the interior part thereof. Pressing roller  6   b  is provided at its each end with a pressing element  621  capable of abutting the pressing roller  6   b  with a predetermined pressure against heat roller  6   a . In addition a sheet separation claw  622  and a roller surface cleaning element  623  are provided on the outer periphery of pressing roller  6   b , similarly to the outer periphery of heat roller  6   a.    
   In this fixing unit  6 , as shown in  FIG. 2  the unfixed toner on the paper P being conveyed is heated and fused by heat roller  6   a , at the pressed contact (so-called fixing nip portion)  600  between heat roller  6   a  and pressing roller  6   b , so that the unfixed toner is fixed to the paper P by the anchoring effect to the paper P by the pressing force from heat roller  6   a  and pressing roller  6   b.    
   Paper feed tray  8  ( FIG. 1 ) stacks a plurality of sheets (paper) to which image information will be output (printed), and is arranged under image forming portion  14  made up of light exposure unit  1 , developing unit  2 , photoreceptor drum  3 , charger  4 , charge erasing device  41 , cleaner unit  5 , fixing unit  6  etc. A paper pickup roller  8   a  is disposed at an upper part on the paper delivery side of this paper feed tray  8 . 
   This paper pickup roller  8   a  picks up paper P, sheet by sheet, from the topmost of a stack of paper stored in paper feed tray  8 , and conveys the paper downstream (for convenience&#39; sake, the delivery side of paper P (the cassette side) is referred to as upstream and the paper output side is referred to as downstream) to the registration roller (also called “idle roller”)  15  side in paper feed path. 
   Since the image forming apparatus  1 A according to the present example embodiment is aimed at performing high-speed printing operations, a multiple number of paper feed trays  8  each capable of stacking 500 to 1500 sheets of standard-sized paper P are arranged under image forming portion  14 . Further, a large-capacity paper feed cassette  81  capable of storing multiple kinds of paper in large volumes is arranged at the side of the apparatus while a manual feed tray  82  for essentially supporting printing etc. for irregular sized paper is arranged on the top of the large-capacity paper feed cassette  81 . 
   Paper output tray  9  is arranged on the opposite side across the apparatus from that of manual feed tray  82 . It is also possible to configure such a system that instead of paper output tray  9 , a post-processing machine for stapling, punching of output paper and other processes and/or a multi-bin paper output tray etc., may be arranged as an option. 
   Paper conveyor system  7  is laid out between the aforementioned photoreceptor drum  3  and paper feed tray  8 , and conveys paper P supplied from paper feed tray  8 , sheet by sheet, by way of paper feed path  7   a  provided for paper conveyor system  7 , to transfer device  10 , where a toner image is transferred from photoreceptor drum  3  to the paper, further conveying it to fixing unit  6  where the unfixed toner image is fixed to the paper, then conveys the sheet as it is being guided by paper feed paths and branch guides, in accordance with the designated paper output processing mode. 
   In the image forming apparatus  1 A according to the present example embodiment, two predetermined paper output processing modes, namely, one-sided printing mode and two-sided printing mode are prepared. In one-sided printing mode, there are two ways of paper output, i.e., the faceup output by which the paper is discharged with its printed surface faceup and the facedown output by which the paper is discharged with its printed surface facedown. 
   Now, paper feed path  7   a  provided for paper conveyor system  7  will be described in detail with reference to the drawings.  FIG. 3  is an illustrative view showing the configuration of paper feed paths in the image forming apparatus according to the present example embodiment; and  FIG. 4  is a partial detailed view showing the configuration of branched paper feed paths for the paper feed paths and branch guides for connection therebetween. 
   As shown in  FIGS. 3 and 4 , paper conveyor system  7  is essentially composed of a first paper feed path  7   a   1  extending from paper feed tray  8  to registration roller  15 , a second paper feed path  7   a   2  extending from registration roller  15  and passing through transfer device  10  and fixing unit  6  to a conveyance roller  16  on the downstream side, a third paper feed path  7   a   3  extending from conveyance roller  16  to a paper discharge roller  17  for discharging paper to paper output tray  9 , a fourth paper feed path  7   a   4  ( FIG. 4 ) for inverting paper P from conveyance roller  16 , a fifth paper feed path  7   a   5  ( FIG. 4 ) connected to fourth paper feed path  7   a   4  and extending to an inversion conveyance roller  18  for re-feeding paper P to registration roller  15 , a sixth paper feed path  7   a   6  ( FIG. 4 ) for conveying paper P in reverse from paper discharge roller  17 , a seventh paper feed path  7   a   7  ( FIG. 4 ) connected to the sixth paper feed path and avoiding entrance to fifth paper feed path  7   a   5  and an eighth paper feed path  7   a   8  ( FIG. 4 ) connected to seventh paper feed path  7   a   7  and extending to a switchback roller  19 . 
   Here, inside paper feed paths  7   a  a multiple number of paper P can occupy depending on the processing mode. In the present example embodiment, eight sheets of paper P may be present at locations ( 1 ) to ( 8 ) (represented by encircled numerals in the drawing) in paper feed paths  7   a , as shown in  FIG. 3 . The number of paper P permissible to be present in the paper feed paths can be different depending on the paper feed path configuration. Further, a plurality of branch guides for switching the route of paper P&#39;s conveyance by selecting the paper feed path in accordance with the selected processing mode are arranged at branch points. 
   As shown in  FIG. 4 , a branch guide  20   a  that selects connection to third paper feed path  7   a   3  or fourth paper feed path  7   a   4  is pivotably arranged at a point downstream of conveyance roller  16 . This branch guide  20   a  is operated by an unillustrated solenoid. This branch guide  20   a  is adapted to operate by an unillustrated solenoid. 
   A branch guide  20   b  that connects fourth paper feed path  7   a   4  with fifth paper feed path  7   a   5  or fifth paper feed path  7   a   5  with sixth paper feed path  7   a   6  is pivotably arranged on the downstream side of fourth paper feed path  7   a   4 . This branch guide  20   b  is operated by the elastic force of an unillustrated spring member and the rigidity of paper P. 
   A branch guide  20   c  that selects connection to fifth paper feed path  7   a   5  or seventh paper feed path  7   a   7  is pivotably arranged on the downstream side of sixth paper feed path  7   a   6 . This branch guide  20   c  is adapted to operate by an unillustrated solenoid. 
   A branch guide  20   d  that connects seventh paper feed path  7   a   7  with eighth paper feed path  7   a   8  or fifth paper feed path  7   a   5  with eighth paper feed path  7   a   8  is pivotably arranged on the downstream side of seventh paper feed path  7   a   7 . This branch guide  20   d  is adapted to operate by an unillustrated solenoid. 
   A branch guide  20   e  for assuring smooth connection from fourth paper feed path  7   a   4  or eighth paper feed path  7   a   8  to fifth paper feed path  7   a   5  is pivotably arranged on the upstream side of fifth paper feed path  7   a   5 . 
   With the thus configured paper feed path  7 , branch guides  20   a  to  20   d  are operated in accordance with the requested processing mode, whereby it is possible to select a conveyance route of paper P corresponding to the processing mode. 
   Next, the configuration of the developing unit and toner feed device provided for the image forming apparatus according to the present example embodiment will be described with reference to the drawings.  FIG. 5  is an overall sectional side view showing a developing unit and toner feed device provided for the image forming apparatus according to the present example embodiment.  FIG. 6  is an overall front view showing the toner feed device in the present example embodiment, viewed in the P-direction in  FIG. 5 . 
   As shown in  FIG. 5 , the exterior of developing unit  2  is formed by a hopper  200 , which has a toner input port  201  for receiving toner at a position where the developing unit abuts an opening  30   a  of toner feed device  30  for supplying toner. Arranged inside hopper  200  are a developing roller  202 , a paddle roller  203 , a mixing roller  204 , a conveying roller  205 , a partitioning plate  206  and a doctor  207  as a regulating member. 
   In hopper  200 , the toner that was fed from toner feed device  30  and input through toner input port  201  is conveyed by conveying roller  205  to mixing roller  204 , where the toner is mixed with a magnetic carrier to thereby prepare a dual-component developer. This developer as it is being agitated by paddle roller  203  is supplied to developing roller  202  for development of electrostatic latent images and conveyed by the electrostatic latent image supported on photoreceptor drum  3 . The developer supplied to developing roller  202  is regulated as to its amount of supply by doctor  207 . The extra developer cut off thereby is recirculated by partitioning plate  206  so that it goes away from doctor  207 . 
   Toner feed device  30  is arranged adjacent to developing unit  2 , and temporarily reserves the toner discharged from toner container  300  filled with toner, in intermediate hopper  33  and then feeds the toner to developing unit  2 . In the present example embodiment, toner container  300  is configured so that container body  310  charged with toner is rotatably supported by a supporting structure  350 . 
   As shown in  FIG. 6 , one side end of container body  310  of toner container  300  is coupled to a main body-side coupler  800  arranged on the main body of image forming apparatus  1 A. Main body-side coupler  800  has an approximately disk-shaped joint socket  801  which is rotated by driving force from a drive source  805  such as a motor etc., of image forming apparatus  1 A. This joint socket  801  and container body  310  are coupled to each other. Describing the coupling of these in further detail, a recessed fitting arrangement  802  for receiving fitting projections  311  and a refill port cap  312  arranged on one side end of container body  310  is provided for joint socket  801 . As toner container  300  is moved so that one end of container body  310  where fitting projections  311  and refill port cap  312  are formed advances toward joint socket  801  (in the S-direction shown in  FIG. 6 ), fitting projections  311  and refill port cap  312  fit into recessed fitting arrangement  802  formed in joint socket  801  when toner container  300  is mounted to image forming apparatus  1 A. Thus container body  310  is coupled to joint socket  801 . In the state where container body  310  is being coupled to joint socket  801 , toner container  300  is set on intermediate hopper  33 , and a toner feed aperture  300   a  formed in supporting structure  350  of container body  310  and an opening  33   a  formed in intermediate hopper  33  are positioned so as to establish communication therebetween. 
   As shown in  FIG. 6 , joint socket  801  is attached to a rotary shaft  804  so that its center corresponds to the rotational center of rotary shaft  804  that penetrates through a chassis  808  of image forming apparatus  1 A. A spring member  803  such as a compression coil spring or the like is attached on rotary shaft  804  between chassis  808  and joint socket  801 . Spring member  803  urges joint socket  801  in such a direction as to bring the socket away from chassis  808 . Therefore, in order that toner feed device  30  will press joint socket  801 , an unillustrated limiting member is provided so that movement of toner feed device  30  in the direction of attachment is limited. 
   As described above, in toner feed device  30  mounted to image forming apparatus  1 A, the driving force from drive source  805  of image forming apparatus  1 A is transmitted to joint socket  801  by way of a decelerator  806  such as gears etc. and rotary shaft  804 , so as to turn this joint socket  801 . As a result, container body  310  rotates about the cylinder axis of container body  310  so as to discharge toner from container body  310  and send it out to intermediate hopper  33  through toner feed aperture  300   a  formed in supporting structure  350 . 
   The toner thus sent out to intermediate hopper  33  is agitated therein by an agitator  34  first. Agitator  34  is composed of an agitator shaft  34   a  and agitating vanes  34   b  attached thereto, as shown in  FIG. 6 . As agitator shaft  34   a  turns, agitating vanes  34   b  rotate about agitator shaft  34   a  to thereby agitate the toner in intermediate hopper  33  that has been fed from toner container  300 . The toner thus agitated by agitator  34  is sent by the agitating action of agitator  34  and conveyed to the feed roller  36  ( FIG. 5 ) side via conveying roller  35  ( FIG. 5 ). Feed roller  36  sends out the toner that has been conveyed from agitator  34  via conveying roller  35  to opening  30   a  that is formed at the position where intermediate hopper  33  abuts developing unit  2 , to thereby supply the toner to developing unit  2 . 
   Provided on the bottom side (the underside when toner container  300  is mounted on image forming apparatus  1 A) of supporting structure  350  of toner container  300  is a shutter opening and closing mechanism  400  for opening and closing toner feed aperture  300   a  through which toner from toner container  300  is discharged out of supporting structure  350 , as shown in  FIG. 5 . Specifically, as toner feed aperture  300   a  of supporting structure  350  is released by shutter opening and closing mechanism  400 , communication between toner feed aperture  300   a  and opening  33   a  provided for intermediate hopper  33  is established, so that the toner discharged from toner container  300  is supplied to intermediate hopper  33 . Here, the configuration and operation of shutter opening and closing mechanism  400  in the present example embodiment will be described later. 
   Next, the configuration of the toner container in the present example embodiment will be described with reference to the drawings.  FIG. 7  is a front view showing a toner container in the present example embodiment;  FIG. 8  is a front view showing how the toner container of the present example embodiment is assembled; and  FIG. 9  is a side view, viewed in the Q-direction in  FIG. 8 . Here,  FIGS. 7 and 8  are front views, viewed in the direction opposite to the P-direction in  FIG. 5 .  FIG. 10  is a rear side view of the container body shown in  FIG. 8 .  FIG. 11A  is a perspective view showing the end part of the container body of the present example embodiment, at the side coupled to the main body-side coupler;  FIG. 11B  is a front view of the same end part;  FIG. 12  is a partial perspective view, viewed from the front side, for explaining the configuration around the toner discharge aperture of the container body in the present example embodiment,  FIG. 13  is a partial perspective view, viewed from the rear side of the container body shown in  FIG. 12 ;  FIG. 14A  is a perspective view showing a configuration of a first supporting member of a supporting structure in the present example embodiment; and  FIG. 14B  is a perspective view showing a configuration of a second supporting member of the supporting structure in the present example embodiment. 
   As described already, toner container  300  ( FIG. 7 ) has a configuration including approximately cylindrical container body  310  and supporting structure  350 . As shown in  FIGS. 8 and 9 , container body  310  is rotatably supported by supporting structure  350  assembled of approximately semi-cylindrical first and second supporting members  350   a  and  350   b.    
   Container body  310  is composed of, as shown in  FIG. 10 , three approximately cylindrical parts, namely, first container part  315 , second container part  316  and third container part  317 . Each of these container parts is integrally formed by blow molding of a synthetic resin such as polyphenylene ether, polyethylene or the like, for example. The aforementioned third container part  317  is disposed between first and second container parts  315  and  316 . The first and second container parts  315  and  316  have bottom portions  318  and  319 , respectively, which constitute the bottoms of cylindrical container body  310 . The thus constructed container body  310  has a toner storing portion for storing toner therein. Formed on the outer peripheral surface at the approximate center of third container part  317  of container body  310  is a toner feed recess  313 , depressed radially inwards. At one end of this toner feed recess  313  there is a toner discharge aperture  314  ( FIG. 8 ) for discharging toner from toner container  310 , as will be described below. Container body  310  is rotated about the cylinder axis AX of the length of container body  310  as third container part  317  of the thus constructed container body  310  is being supported by supporting structure  350 , so that toner is discharged from toner discharge aperture  314  to toner feed recess  313  which is formed on the outer peripheral surface of toner container  310 . Here, the Q-direction in  FIG. 8  is the same as the direction in which cylinder axis AX extends. 
   First container part  315  ( FIGS. 8 and 10 ) is arranged on the side where the aforementioned main body-side coupler  800  (see  FIG. 6 ) of the image forming apparatus is located. Accordingly, bottom portion  318  of first container part  315  is formed with four fitting projections  311  that project from bottom  318  as a coupler to be coupled with main body-side coupler  800 , as shown in  FIGS. 11A and 11B . These fitting projections  311  are arranged so that opposing fitting projections are positions essentially point symmetrically about the center of bottom portion  318  or the cylinder axis AX of approximately cylindrical container body  310 . Toner feed device  30  is attached to main body-side coupler  800  of image forming apparatus  1 A by means of these fitting projections  311 , and container body  310  receives driving force from a drive source from image forming apparatus  1 A and rotates about cylinder axis AX. 
   Further, bottom portion  318  has an opening penetrating therethrough as a toner supply port  320 , to which refill port cap  312  is removably fitted. Toner refill port  320  is provided to refill container body  310  of toner container  300  with toner and is formed in the center of bottom portion  318  in a circular shape centered at the aforementioned cylinder axis. Refill port cap  312  totally covers toner refill port  320  and seals it. This refill port cap  312  is fitted to toner refill port  320  in such a manner that it will not come off due to rotation of container body  310  about the cylinder axis. Further, refill port cap  312  is adapted to be detached from toner refill port  320  when toner is loaded from toner refill port  320  into container body  310 . 
   Formed on the inner surface of the peripheral side of the aforementioned first container part  315  (to be referred to as inner peripheral surface) are a plurality of conveyor elements  321  in order to convey the toner inside container body  310  of toner container  300  along the direction of the cylinder axis. These conveyor elements  321  are formed projectively from the inner peripheral surface toward the cylinder axis AX (radially inwards of container body  310 ), at regular intervals with respect to the peripheral direction and the cylinder axis direction of first container part  315 . Conveyor elements  321  are arranged parallel to each other in the cylinder axis direction. 
   The aforementioned conveyor elements  321  are formed being inclined at a predetermined angle with the direction of a line that lies on the inner peripheral surface and is perpendicular to the cylinder axis AX of container body  310 , in order to convey toner from the bottom portion  318  side toward third container part  317  ( FIG. 10 ). In other words, each of these conveyor elements  321  is formed so that its downstream end is located closer to third container part  317  having toner discharge aperture  314  ( FIG. 8 ) than its upstream end, with respect to the direction of rotation of container body  310  about the cylinder axis. 
   Second container part  316  is formed with bottom portion  319  of container body  310  and arranged in approximately cylindrical container body  310  at the end that is opposite to the side where main body-side coupler  800  (see  FIG. 6 ) provided for image forming apparatus  1 A is laid out, as shown in  FIG. 10 . The inside diameter of second container part  316  is formed so as to be equal to that of first container part  315 . 
   Formed on the inner peripheral surface of second container part  316  are a plurality of conveyor elements  322  in order to convey the toner inside container body  310  along the direction of the cylinder axis AX. These conveyor elements  322  are formed projectively from the inner peripheral surface toward the cylinder axis, at regular intervals with respect to the peripheral direction and the direction of cylinder axis AX of second container part  316 . Conveyor elements  322  are arranged parallel to each other. 
   The aforementioned conveyor elements  322  are formed being inclined at a predetermined angle with the direction of a line that lies on the inner peripheral surface and is perpendicular to the cylinder axis AX of container body  310 , in order to convey toner from the bottom portion  319  side toward third container part  317 . In other words, each of these conveyor elements  322  is formed so that its downstream end is located closer to third container part  317  having toner discharge aperture  314  than its upstream end, with respect to the direction of rotation of container body  310  about the cylinder axis. 
   Further, as shown in  FIGS. 10 and 13 , a container body-side engaging projection  335  that will engage shutter opening and closing mechanism  400  ( FIG. 5 ) provided for supporting structure  350  ( FIG. 5 ) is formed on the outer peripheral surface of second container part  316  at a position close to third container part  317 . Detailed position and other aspects of this container body-side engaging projection  335  will be described later. 
   As described heretofore, since container body  310  of toner container  300  of the present example embodiment has third container part  317  between first container part  315  and second container part  316 , the inclination of conveyor elements  322  formed in second container part  316  is formed opposing that of conveyor elements  321  formed in first container part  315 . As a result, as container body  310  rotates about the cylinder axis (in the R-direction in  FIG. 9 ), the toner stored in the first container part  315  and the toner stored in the second container part  316  move towards third container part  317 , being guided by conveyor elements  321  and  322  from bottom portions  318  and  319  of container body  310 , respectively. 
   As described above, third container part  317  is the portion that is rotatably supported by supporting structure  350 , and its inside diameter is formed marginally greater than that of first and second container parts  315  and  316 , as shown in  FIGS. 8 and 10 . With this configuration, the toner conveyed from the first and second container parts  315  and  316  can be correctly conveyed and brought down into third container part  317 , so that it is possible to constantly hold a uniform amount of toner inside third container part  317 . Accordingly, even when container body  310  stops rotating, third container part  317  holds a predetermined amount of toner, so that it is possible to give a stable supply of toner immediately after container body  310  is restarted to rotate. Further, since a fixed amount of toner can be held in third container part  317  if the remaining amount of toner in container body  310  has become lower, it is possible to make stable supply of toner over a long period. 
   As shown in  FIG. 12 , third container part  317  is formed with a toner feed recess  313  that has a predetermined width with respect to the cylinder axis AX of container body  310  and extends on the outer peripheral surface of container body  310  one round on the outer peripheral surface in the rotational direction of container body  310 . This toner feed recess  313  is formed so that it sinks from the outer surface of the peripheral side of third container part  317  (to be mentioned hereinbelow as the outer peripheral surface) toward the cylinder axis AX. The thus configured toner feed recess  313  serves as a space for holding the toner discharged from container body  310  and is also used as a space for delivering toner from toner feed recess  313  to toner feed aperture  300   a  ( FIGS. 7 and 9 ) formed in supporting structure  350 . Further, since toner feed recess  313  is formed in a depressed configuration on the outer peripheral surface of third container part  317 , it is possible to reduce the contact surface between third container part  317  and supporting structure  350  during rotation of container body  310 . As a result, the friction between supporting structure  350  and container body  310  during rotation of container body  310  can be reduced so as to realize smooth rotation of container body  310  of toner container  300 . 
   As shown in  FIG. 12 , toner feed recess  313  is defined by an end wall portion  313   a , a bottom wall portion  313   b , a first side wall portion  313   c  and a second wall portion  313   d . End wall portion  313   a  is arranged at the downstream end of toner feed recess  313  with respect to the rotational direction R of container body  310  and formed approximately perpendicularly to the outer peripheral surface of third container part  317 . Formed in end wall portion  313   a  is a toner discharge aperture  314  as an opening connected to the interior of container body  310  in order to discharge toner from container body  310  to toner feed recess  313 . 
   Bottom wall portion  313   b  is arranged extending in the rotational direction R so that its downstream end with respect to the rotational direction R is connected to end wall portion  313   a  while its upstream end is smoothly connected to the outer peripheral surface of third container part  317 . That is, bottom wall portion  313   b  is formed roughly parallel to the outer peripheral surface and closer to cylinder axis AX than the outer peripheral surface of third container part  317  is. 
   The aforementioned first side wall portion  313   c  and second side wall portion  313   d  are arranged so as to be approximately parallel to each other and vertical to the outer peripheral surface of third container part  317  and bottom wall portion  313   b , forming both sides of toner feed recess  313 , i.e., the both sides with respect to the direction of cylinder axis AX of container body  310 . The aforementioned first side wall portion  313   c  and second side wall portion  313   d  are each connected at their downstream ends with respect to the rotational direction R of container body  310  to end wall portion  313   a  while their upstream ends are connected to the outer peripheral surface of third container part  317 . Further, first side wall portion  313   c  and second side wall portion  313   d  are each connected to the outer peripheral surface of third container part  317  at their upstream and downstream sides with respect to the rotational direction R. 
   Further, third container part  317  is formed with an enclosing seal  330  as a sealing element for bonding and sealing toner discharge aperture  314  provided in toner feed recess  313 , as shown in  FIG. 12 . As shown in  FIGS. 9 and 12 , enclosing seal  330  is formed in an approximate arc shape with a predetermined length in the peripheral direction of container body  310  and arranged along the end face on which toner discharge aperture  314  of container body  310  is formed. One end  330   a  of enclosing seal  330  is bonded to toner discharge aperture  314  so as to seal off the toner discharge aperture  314  of toner feed recess  313 . On the other hand, the other end  330   b  of enclosing seal  330  is formed with an engaging hole  331 , which is fixed to supporting structure  350  by engagement with a supporting structure-side engaging projection  351  ( FIG. 9 ) formed in supporting structure  350 . 
   With this configuration, when enclosing seal  330  is peeled off by rotation of container body  310  of toner container  300 , second end  330   b  of enclosing seal  330  is pulled by supporting structure-side engaging projection  351  of supporting structure  350  as container body  310  rotates in the direction of arrow R, and the first end  330   a  of enclosing seal  330  is peeled off toner discharge aperture  314  so as to open toner discharge aperture  314 . In contrast, when container body  310  rotates in the direction opposite the direction of arrow R, the second end  330   b  of enclosing seal  330  is hooked by supporting structure-side engaging projection  351  provided for supporting structure  350  (first supporting member  350   a ) so that enclosing seal  330  pulls container body  310 . As a result, the rotation of container body  310  in the opposite direction can be prevented, thus stabilizing container body  310  without its being rattled during toner container  300  is being conveyed or the like. 
   As to the material of enclosing seal  330 , in order to reduce the difference in pressure between the interior and exterior of container body  310 , a material having air permeability is preferably used. Also, since it is preferred to prevent adherence of moisture to enclosing seal  330  and the toner inside container body  310 , the enclosing seal is preferably formed of a material having hygroscopicity. Further, enclosing seal  330  is preferably formed of a material that is slidable and can be bonded to seal the toner discharge aperture  314  by thermal compression bonding etc. Examples of the martial for enclosing seal  330  meeting the above conditions include; polyethylene terephthalate (PET), polyethylene, polypropylene, felt and the like. In the present example embodiment, the enclosing seal  330  is formed of a sheet of paper made of polyester (PET) or the like, being coated with a felt made of extra fine polyester fiber, specifically, a product of Du Pont Kabushiki Kaisha “Tyvek” (registered trademark). 
   On the other hand, supporting structure  350  is constructed of, as already described, approximately semi-cylindrical first and second supporting members  350   a  and  350   b , and this supporting structure  350  rotatably supports third container part  317  located in the approximate center of container body  310 . 
   First supporting member  350   a  has an approximately semi-cylindrical configuration as shown in  FIG. 14A  and is formed with the aforementioned toner feed aperture  300   a  at the approximate center of its inner side curved surface portion  353   a . Also formed at the approximately center of inner side curved surface  353   a  of first supporting member  350   a  is a regulating recess  358  into which a regulating member  405   b  ( FIG. 16 ) for limiting the moving range of the closing operation of a shutter element  401  ( FIG. 16 ) of the aftermentioned shutter opening and closing mechanism  400  fits ( FIG. 14A  shows a state where regulating member  405   b  has fitted therein). This regulating member  405   b  is arranged with its approximately U-shaped part projected from inner peripheral curved surface  353   a  of first supporting member  350   a  and has such a height (the amount of projection from inner peripheral surface  353   a ) as to abut container body  310  when supporting structure  350  supports container body  310 . Accordingly, when shutter element  401  of shutter opening and closing mechanism  400  is closing toner feed aperture  300   a , container body-side engaging projection  335  ( FIGS. 9 and 10 ) formed on the side surface of container body  310  is engaged with regulating member  405   b  ( FIG. 15 ). The operation of container body-side engaging projection  335  becoming engaged with regulating member  405   b  provided for shutter opening and closing mechanism  400  will be described later. 
   Further, in order to secure the clearance for rotation of container body  310  as well as to secure the stability in supporting container body  310  by supporting structure  350 , a pair of rib-like container body engaging portions  359   a  ( FIG. 14 ) are formed on inner curved surface portion  353   a . These container body engaging portions  359   a  are arranged in parallel to each other and spaced approximately the same distance as the width (the dimension in the direction of cylinder axis AX) of third container part  317 . These engaging portions  359   a  are connected to corresponding container body engaging portions  359   b  formed on the aftermentioned second supporting member  350   b  when first supporting member  350   a  and second supporting member  350   b  are assembled to complete supporting structure  350 . The thus constructed paired ribs of container body engaging portions  359   a  and  359   b  and inner peripheral curved surfaces  353   a  and  353   b  hold third container part  317  to thereby support container body  310  in a rotatable manner on supporting structure  350 . 
   In addition, both the side edges (the parts that are connected to second supporting member  350   b ) of inner peripheral curved surface portion  353   a  are formed with first and second flanges  354   a  and  355   a . In each of flanges  354   a  and  355   a , fitting recesses  356   a  or  357   a  are formed at both longitudinal ends (the sites connected to second supporting member  350   b ) of the flange and are fitted to corresponding fitting projections  356   b  or  357   b  formed at both longitudinal ends of the flange  354   b  or  355   b  of aftermentioned second supporting member  350   b . Formed at the approximate center of first flange  354   a  is a supporting structure-side engaging projection  351  for engagement with engaging hole  331  formed at the other end  330   b  of enclosing seal  330  ( FIG. 8 ). Further, formed on the outer side of first supporting member  350   a , at the position where toner feed aperture  300   a  is arranged, is shutter opening and closing mechanism  400  ( FIG. 15 ) for opening and closing toner feed aperture  300   a . The configuration and operation of shutter opening and closing mechanism  400  will be described later. 
   Second supporting member  350   b  also has an approximately semi-cylindrical configuration as shown in  FIG. 14B . Similarly to first supporting member  350   a , in order to secure the clearance for rotation of container body  310  as well as to secure the stability in supporting container body  310  by supporting structure  350 , a pair of rib-like container body engaging portions  359   b  are formed on inner curved surface portion  353   b . These container body engaging portions  359   b  are arranged in parallel to each other and spaced approximately the same distance as the width of third container part  317 . In addition, both the side edges of inner curved surface portion  353   b  are formed with first and second flanges  354   b  and  355   b . In each of flanges  354   b  and  355   b , fitting projections  356   b  or  357   b  are formed at both longitudinal ends of the flange and are fitted correspondingly to the aforementioned fitting recesses  356  or  357   a  formed at both longitudinal ends of the flange  354   a  or  355   a  of the aforementioned first supporting member  350   a . Formed at the approximate center of first flange  354   b  is an engaging recess  352  that fits supporting structure-side engaging projection  351  formed in first flange  354   a.    
   As first supporting member  350   a  and second supporting member  350   b  are thus configured as above, first flange  354   a  of first supporting member  350   a  is joined to first flange  354   b  of second supporting member  350   b , and second flange  355   a  of first supporting member  350   a  is joined to second flange  355   b  of second supporting member  350   b , to thereby complete the approximately cylindrical supporting structure  350  which supports container body  310  in a rotatable manner over the whole circumference. 
   Next, the shutter opening and closing mechanism provided for the first supporting member in the supporting structure of the toner container of the present example embodiment will be described with reference to the drawings.  FIG. 15A  is a side view showing first supporting member  350   a  of supporting structure  350  of the toner container in the present example embodiment;  FIG. 15B  is a plan view showing first supporting member  350   a , viewed from its bottom side;  FIG. 16A  is a perspective view showing shutter element  401  provided for the shutter opening and closing mechanism in the present example embodiment, viewed from its front;  FIG. 16B  is a perspective view showing the same shutter element  401 , viewed from its rear; and  FIG. 16C  is an illustrative view showing the way in which the shutter element  401  is attached to first supporting member  350   a.    
   As described above, first supporting member  350   a  ( FIG. 15 ) is formed in a semi-cylindrical shape and has toner feed aperture  300   a  formed at the approximate center ( FIG. 14A ) of inner curved surface portion  353   a . Formed along both side edges of inner curved surface portion  353   a  are first and second flanges  354   a  and  355   a.    
   As shown in  FIGS. 15A and 15B , on the bottom side of first supporting member  350   a , a plate-formed, first fixing member  360  ( FIG. 15B ) and second fixing member  361  ( FIG. 15B ) for attachment and fixture of toner container  300  to intermediate hopper  33  ( FIG. 5 ) of toner feed device  30  are formed parallel to each other and erected outside from inner curved surface portion  353   a . Specifically, first fixing member  360  and second fixing member  361  provide the function of a supporting base for the placement face of first supporting member  350   a  so as to hold container body  310  ( FIG. 5 ) supported by supporting structure  350  approximately horizontal. Further, on the downstream side of toner feed aperture  300   a  located between first fixing member  360  and second fixing member  361 , a shutter opening and closing mechanism  400  for making control of discharge of the toner supplied from container body  310  to the outside by switching the state of the shutter over the opening on the downstream side of toner feed aperture  300   a  ( FIG. 15A ) between the open and closed states is arranged. Accordingly, first fixing member  360  and second fixing member  361  are adjusted as to their height so as to establish the clearance between supporting structure  350  and intermediate hopper  33  of toner feed device  30  so that shutter opening and closing mechanism  400  will function correctly. 
   As shown in  FIG. 15B , shutter opening and closing mechanism  400  is comprised of shutter element  401  for opening and closing toner feed aperture  300   a , first and second regulating members  402  and  403  formed at the side of shutter element  401  and an anti-slide rib  404  formed on the bottom of first supporting structure  350   a , standing erect with respect to the sliding surface of shutter element  401 . 
   Shutter element  401  is an approximately rectangular plate-like member formed of a synthetic resin or the like having a certain degree of elasticity and hardness, such as POM (polyoxymethylene) or the like, and has a guide portion  405  that is extended from one end on the side from which shutter element  401  starts to open (to be referred to hereinbelow as the front end side) so as to guide the opening and closing action of shutter element  401  along the fixed direction. Guide portion  405  is integrally formed with shutter element  401 , and has erected pieces  405   a  standing upright along both side edges thereof. These erected pieces are formed inclined, reducing their height from their proximal side connected to shutter element  401  toward the distal side, as shown in  FIG. 16A . On the front end side of guide portion  405 , approximately U-shaped regulating member  405   b  that limits the movable range of the closing action of shutter  401  is formed erected on the opposing side of erected pieces  405   a  of guide portion  405 . As described already, this regulating member is fitted into regulating recess  358  ( FIG. 14A ) formed at the approximate center near the side end of inner curved surface  353   a  of first supporting member  350   a , so as to limit the movable range of the closing action of shutter element  401 . Further, regulating member  405   b  is engaged with container body-side engaging projection  335  ( FIGS. 9 and 10 ) when shutter element  401  of shutter opening and closing mechanism  400  shuts up toner feed aperture  300   a.    
   First regulating member  402  is to limit the movement of shutter element  401  before mounting toner container  300  to intermediate hopper  33 . As shown in  FIGS. 16A and 16B , this regulating member is composed of an approximately L-shaped main piece  402   a , whose one end is connected to the side part of shutter element  401  and the other end being extended to the front end side, and a hook  402   b  that is formed at the front end side of this main piece  402   a  and projected outside (to the left in  FIG. 15 ). This hook  402   b  abuts anti-slide rib  404  ( FIG. 15B ) so as to serve as an anti-sliding means for preventing shutter element  401  of shutter opening and closing mechanism  400  from being opened when toner container  300  has not been mounted to intermediate hopper  33 . In other words, combination of first regulating member  402  and anti-slide rib  404  constitute the anti-sliding means for preventing shutter element  401  from sliding before toner container  300  is mounted to intermediate hopper  33 . First regulating member  402  is formed of a material having a certain degree of elasticity and hardness such as POM (polyoxymethylene) or the like so as to deflect in the width direction of shutter element  402 . The details of how first regulating element  402  and anti-slide rib  404  operate to prevent shutter element  401  from sliding will be described later. 
   The second regulating member  403  is provided to limit the movement of shutter element  401 . This is particularly used when shutter element  401  that has been opened is closed. This second regulating member  403  is composed of, as shown in  FIG. 16A , an approximately L-shaped main piece  403   a , whose one end is connected to the side part of shutter element  401  and the other end being extended in the direction opposite to first regulating member  402 , and a hook  403   b  that is formed at the opposite end from the connected side of this main piece  403   a  to shutter element  401  and is projected in the direction (upwards in  FIG. 16A ) opposite to toner feed aperture  300   a . Similarly to first regulating member  402 , second regulating member  403  is also preferably formed of a material having a certain degree of elasticity and hardness such as POM (polyoxymethylene) or the like. The details of how second regulating element  403  operates to limit the movement of shutter element  401  will be described later. 
   On the other hand, formed on the underside of shutter element  401  are a pair of slide supporting elements  406  which support the shutter element to a shutter guide portion  370  ( FIG. 16C ) having the aforementioned toner feed aperture  300   a  of supporting structure  350  formed therein and are extended in the longitudinal direction of shutter element  401 , as shown in  FIG. 16B . That is, as shown in  FIG. 16C , slide supporting elements  406  each have a hooking portion  406   a  formed so as to project inwards (toward the opposing side) from the both side edges of shutter element  401 , whereby the shutter element can be supported in a slidable manner along, and by, slide recessed portion  370   a  formed in shutter guide portion  370 . 
   Further, on the bottom side of first supporting member  350   a , in other words, on the side where shutter opening and closing mechanism  400  is disposed in first supporting member  350   a , a pair of erected portions  362  ( FIGS. 15A and 15B ) that are erected to the bottom surface are provided between the outer portion of first supporting member  350   a , and first regulating member  402  and anti-slide rib  404 , in order to prevent hands, fingers etc. from touching first regulating member  402  from the outside when toner container  300  has been set on intermediate hopper  33 . In the present example embodiment, these erected portions  362  are disposed in the end part on the bottom side of first supporting member  350   a  so that they abut the front end of guide portion  405 . 
   Next, the configuration of the mount surface on which toner container  300  of the present example embodiment is set to intermediate hopper  33  ( FIG. 5 ) will be described with reference to the drawings.  FIG. 17  is a partial perspective view showing essential parts in the mount surface of the intermediate hopper on which the toner container of the present example embodiment is mounted. In  FIG. 17 , of the toner container mount surface in the intermediate hopper, the part located on the side opposite to the main body-side coupler  800  ( FIG. 6 ) is shown. In this figure, arrow S represents the direction in which toner container  300  is moved so as to be mounted to main body-side coupler  800 , and the starting point side of arrow S is expressed as the upstream side. 
   In the present example embodiment, the toner container mount surface  340  of intermediate hopper  33  to which supporting member  350   a  is mounted, has opening  33   a  that will communicate with toner feed aperture  300   a  when shutter opening and closing mechanism  400  is released, at the position corresponding to toner feed aperture  300   a  ( FIG. 14A ) provided for supporting structure  350 , as shown in  FIG. 17 . That is, opening  33   a  is formed at such a position as to receive the toner discharged from toner feed aperture  300   a  when toner feed aperture  300   a  of supporting member  350   a  is released by shutter opening and closing mechanism  400  after toner container  300  ( FIG. 7 ) has been mounted to toner container mount surface  340 . 
   Arranged on the upstream side of opening  33   a  in toner container mount surface  340  is a shutter block  341  for releasing the anti-slide function for limiting the movement of shutter element  401  of shutter opening and closing mechanism  400  for closing toner feed aperture  300   a  of supporting structure  350  when toner container  300  has been mounted to intermediate hopper  33 . This shutter block  341  is an approximately triangular prism-shaped projected member having an inclined surface  341   a  ( FIG. 18B ) and is arranged with its length approximately parallel to the S-direction. The distance from the downstream end of shutter block  341  to opening  33   a  is designed to be approximately equal to the distance from the downstream end of shutter element  401  ( FIG. 16A ) to hook  402   b  ( FIG. 16A ) of first regulating member  402 . Since shutter block  341  is laid out on the upstream side of opening  33   a  of mount surface  340  in the above way, shutter block  341  abuts hook  402   b  when toner container  300  is set to intermediate hopper  33 . As a result, main piece  402   a  of first regulating member  402  bends inwards so that hook  402   b  becomes deviated from anti-slide rib  404  ( FIG. 15B ), hence the constraint on the movement of shutter element  401  by anti-slide rib  404  is released. 
   Further, a first engaging projection  342  is provided at a position opposing an aftermentioned second engaging projection  343 , which is arranged on the downstream side of shutter block  341  on toner container mount surface  340  and near opening  33   a . This first engaging projection  342  is disposed at such a position as to abut shutter element  401  ( FIG. 16 ) when toner container  300  is mounted on intermediate hopper  33  and slid in the S-direction. Accordingly, when toner container  300  is set on intermediate hopper  33  and slid in the S-direction after the anti-slide function for limiting the movement of shutter element  401  is released, first engaging projection  342  abuts the downstream end of shutter element  401 , to thereby open shutter element  401  with the movement of toner container  300  in the S-direction. 
   Further, arranged on the downstream side of shutter block  341  of toner container mount surface  340  and near opening  33   a  is second engaging projection  343  opposing first engaging projection  342  as mentioned above. This second engaging projection  343  is hooked by hook  403   b  of second regulating member  403  ( FIGS. 16A and 16B ) of shutter opening and closing mechanism  400  when toner container  300  is dismounted from intermediate hopper  33  of toner feed device  30 , so that shutter element  401  shuts up toner feed aperture  300   a . That is, shutter element  401  is moved in linkage with the dismounting action of toner container  300  from intermediate hopper  33 , to thereby close toner feed aperture  300   a  of toner container  300 . 
   Also, a pair of supporting pieces  344  for supporting the rear end part (the rear end on the bottom surface  319  side ( FIG. 7 ) of second container part  316 ) of container body  310  when toner container  300  is being mounted is formed in toner container mount surface  340  on the upstream side of shutter block  341  of opening  33   a . These supporting pieces  344  are to create a predetermined clearance between container body  310  of toner container  300  and toner container mount surface  340  and contributes to smooth rotation of container body  310 . The shape and configuration of these supporting pieces  344  are not particularly limited. That is, these supporting pieces may be formed in any shape with any material as long as it enables container main body  310  of toner container to rotate smoothly. 
   Next, the releasing operation of shutter opening and closing mechanism  400  provided for toner container  300  in the present example embodiment will be described with reference to the drawings.  FIG. 18A  is a plan view showing first supporting member  350   a , viewed from the bottom side when toner container  300  of the present example embodiment is set on intermediate hopper  33  and staffs to be slid in the S-direction after the anti-slide function is released;  FIG. 18B  is a side view showing the vicinity of a hook of first supporting member  350   a  when toner container  300  of the present example embodiment is set on intermediate hopper  33  and is being slid in the S-direction after the anti-slide function is released;  FIG. 19A  is a plan view showing first supporting member  350   a , viewed from the bottom side when toner container  300  of the present example embodiment is set on intermediate hopper  33  and slid in the S-direction to open shutter element  401  after the anti-slide function is released; and  FIG. 19B  is a side view showing the vicinity of a hook of first supporting member  350   a  when toner container  300  of the present example embodiment is set on intermediate hopper  33  and slid in the S-direction to open shutter element  401  after the anti-slide function is released. 
   As toner container  300  is set on toner container mount surface  340  of intermediate hopper  33  and slid in the S-direction, shutter block  341  provided for toner container mount surface  340  abuts hook  402   b  of first regulating member  402  as shown in  FIG. 18A . As a result, shutter block  341  pushes first regulating member  402  to the interior side so that hook  402   b  of first regulating member  402  becomes disengaged from anti-slide rib  404  as shown in  FIG. 18B . That is, the anti-slide function by first regulating member  402  and anti-slide rib  404  is released. In this action, since the portion where hook  402   b  of first regulating member  402  abuts shutter block  341  is formed as an inclined surface  402   c  as shown in  FIG. 18B , hook  402   b  can be easily deflected to the interior side of anti-slide rib  404  by the inclined surface portion, designated at  341   a , of shutter block  341 . Here, in a configuration where hook  402   b  of first regulating member  402  abuts shutter block  341  when toner container  300  is set on toner container mount surface  340 , the anti-slide function between first regulating member  402  and anti-slide rib  404  is disengaged. 
   As toner container  300  is slid in the S-direction after the above anti-slide function has been released, first engaging projection  342  abuts the end part of shutter element  401  so that shutter element  401  is opened with the movement of toner container  300  (supporting structure  350 ) in the S-direction, toner feed aperture  300   a  establishes communication with opening  33   a  of intermediate hopper  33  ( FIG. 19A ). That is, in the present example embodiment, upon mounting toner container  300  to intermediate hopper  33  of toner feed device  30  ( FIGS. 5 and 17 ), toner feed aperture  300   a  is adapted to open by releasing restriction on the movement of shutter element  401  by anti-slide means in linkage with this mounting action. Here in the present example embodiment, when shutter element  401  is moved by sliding toner container  300  in the S-direction to the position where toner feed aperture  300   a  is completely open, the movement of shutter element  401  in the S-direction is limited by erected portions  362  as shown in  FIG. 19A . 
   Next, the operation of an anti-rotation mechanism for container body  310  provided for toner container  300  in the present example embodiment will be described with reference to the drawings.  FIG. 20A  is an illustrative view, viewed from the width direction of the toner container, for explaining how shutter opening and closing mechanism  400  prevents the container body from being rotated when container body  310  of toner container  300  of the present example embodiment is supported by supporting structure  350 ;  FIG. 20B  is an illustrative view, viewed from the width direction of the toner container, for explaining the operational state where the toner container is rotated in the reverse direction (in the IR-direction) of the forward direction (in the R-direction) for feeding toner when the container body of the toner container of the present example embodiment is supported by the supporting structure;  FIG. 21A  is an illustrative view, viewed from the width direction of the toner container, for explaining the operational state where the toner container is rotated in the IR-direction when the shutter opening and closing mechanism provided for the toner container of the present example embodiment is broken or damaged and hence the anti-rotation mechanism of the container body by the shutter opening and closing mechanism does not function; and  FIG. 21B  is an illustrative view, viewed from the width direction of the toner container, for explaining the operational state where the shutter opening and closing mechanism provided for the toner container of the present example embodiment is released and the container body is rotated in the R-direction to peel off the enclosing seal. Here, for easy description of the operation of the anti-rotation mechanism of the container body, the toner feed recess and the container body-side engaging projection formed in the container body are shown as if they were on the same plane though they are actually not. 
   Before toner container  300  is mounted to intermediate hopper  33  of toner feed device  30 , shutter element  401  of shutter opening and closing mechanism  400  ( FIG. 20 ) has been locked so as not to be opened as already described. Accordingly, container body-side engaging projection  335  is hooked and stopped by regulating member  405   b  ( FIG. 16 ) provided on the front end side of guide portion  405  of shutter opening and closing mechanism  400 . In this condition, if container body  310  rotates in the R-direction ( FIG. 20 ), the inner wall portion, designated at  405   b   1 , of regulating member  405   b  formed in the front end side of guide portion  405  of shutter opening and closing mechanism  400  engages and stops container body-side engaging projection  335  and prevents the rotation of container body  310  in the R-direction, as shown in  FIG. 20A . On the contrary, if container body  310  rotates in the IR-direction, the inner wall portion, designated at  405   b   2 , of regulating member  405   b  engages and stops container body-side engaging projection  335  and also prevents the rotation of container body  310  in the IR-direction, as shown in  FIG. 20B . That is, container body-side engaging projection  335  engages and stops shutter opening and closing mechanism  400  that closes toner feed aperture  300   a , so that it is possible to prevent container body  310  supported by supporting structure  350  from rotating erroneously due to unexpected impacts, vibrations or the like during shipment or transportation of container body  310 . 
   Further, even in such an anomaly condition as shutter opening and closing mechanism  400  provided for toner container  300  of the present example embodiment is broken or damaged so that container body-side engaging projection  335  is not latched by shutter opening and closing mechanism  400 , if container body  310  is rotated in the IR-direction as shown in  FIG. 21A , it is possible to prevent container body  310  from rotating in the IR-direction because the second end  330   b  of enclosing seal  330  that bonds and seals toner discharge aperture  314  provided for toner feed recess  313  is held by supporting structure  350  so that enclosing seal  330  pulls container body  310 . Accordingly, even in such an anomaly condition as shutter opening and closing mechanism  400  is broken or damaged, it is possible to prevent container body  310  from rotating in the IR-direction hence keep container body  310  in a stable manner without rattling during transportation and the like of toner container  300 . 
   Moreover, when toner container  300  of the present example embodiment is mounted to intermediate hopper  33  of toner feed device  30  and toner is discharged from toner container  300  to intermediate hopper  33 , shutter opening and closing mechanism  400  provided for supporting structure  350  is released. In this situation, main body-side coupler  800  of image forming apparatus  1 A is driven, and container body  310  rotates in the R-direction. As a result, enclosing seal  330  is peeled off as shown in  FIG. 21B , to thereby open toner discharge aperture  314 . At this point, when container body-side engaging projection  335  comes off shutter opening and closing mechanism  400  and container body  310  is driven to rotate to supply toner, a rotational load equal to or greater than a fixed load is applied to container body  310  from main body-side coupler  800  of image forming apparatus  1 A. That is, as shown in  FIG. 21B , when the angle □ between enclosing seal  330  and the tangent line, designated at L 1 , at the position when enclosing seal  330  of toner container  300  is fixed becomes an acute angle equal to or smaller than  90  degrees, the rotational load applied to container body  310  from main body-side coupler  800  of image forming apparatus  1 A becomes great. As a result, it is possible to prevent container body  310  from being easily rotated by external force such as human strength or the like even when shutter opening and closing mechanism  400  is broken or in any other anomaly condition. Hence it is possible to prevent enclosing seal  330  applied to toner discharge aperture  314  of container body  310  from peeling off before toner container  300  is used, thus improving toner container  300  in maintenance performance. 
   As described heretofore, when shutter opening and closing mechanism  400  is being locked so as to keep the closed state of the shutter element, container body-side engaging projection  335  is engaged by shutter opening and closing mechanism  400  that closes toner feed aperture  300   a , hence it is possible to prevent container body  310  supported by supporting structure  350  from being rotated erroneously due to unexpected impacts, vibrations or the like during shipment and transportation of toner container  300 . As a result it is possible to improve the workability and maintenance performance when toner container  300  is mounted. 
   Though the above description was made taking a form of a preferred example embodiment with reference to the accompanying drawings, it goes without saying that the present invention should not be limited to this example. It is apparent that various modifications and variations will occur to those skilled in the art without departing from the spirit or scope of the following claims, and those should be considered to be within the technical scope of the invention. 
   For example, the above first example embodiment is applied to the toner container to be mounted to a monochrome image forming apparatus which uses one toner container. However, the container body anti-rotation mechanism can be also applied to the toner containers for a color image forming apparatus which needs multiple number of toner containers.