Patent Publication Number: US-7711293-B2

Title: Toner container

Description:
This Nonprovisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2006-59771 filed in Japan on 6 Mar. 2006, the entire contents of which are hereby incorporated by reference. 
   BACKGROUND OF THE TECHNOLOGY 
   1. Field of the Technology 
   The present technology relates to a toner container and a toner loading method, in particular relating to a toner container and a method of loading toner into the toner container for use in an image forming apparatus that performs image formation with the toner. 
   2. Description of the Prior Art 
   Conventionally, in image forming apparatuses using toner, such as copiers, facsimile machines, etc., a toner supply device using a toner cartridge is used to supply toner to the developing unit to thereby achieve continuous operation of image output. 
   Examples of generally known methods for supplying toner to the developing unit include: a configuration in which toner stored in a toner cartridge is directly supplied to the developing unit (see Japanese Patent Application Laid-open 2003-162143); and a configuration in which toner in a toner cartridge is supplied by a screw from a predetermined position to the developing unit (see Japanese Patent Application Laid-open Hei 10-142936). 
   From a viewpoint of recent upsurge of conservation of natural resources, there are some proposals of toner cartridges that can be recycled by refilling toner after the toner runs out (see Japanese Patent Application Laid-open 2001-312129). Further, there is also a proposal of a toner cartridge which can display the number of times of recycled usage (see Japanese Patent Application Laid-open Hei 9-288415). 
   However, some conventional toner cartridges have configurations that are not suitable for being recycled, others have the problems that loading of toner into the toner cartridge is troublesome and that toner which spills out from the toner loading opening when toner is loaded, contaminates the operator and apparatus, causing bad influence on work performance. 
   SUMMARY OF THE TECHNOLOGY 
   The present technology has been devised in view of the above conventional problems, it is therefore an object of the present technology to provide a toner container, into which toner can be simply loaded, which can be handled easily when the toner container is full of toner, and which can be easily recycled, as well as to provide a toner loading method whereby the work performance of toner loading can be improved by preventing contamination on the operator and the apparatus with the toner that spills out from the toner loading opening when toner is loaded. 
   The toner container and the toner loading method for solving the above problems are configured as follows. 
   A toner container according to the first aspect includes: a cylindrical toner storing portion to be filled with toner; a toner loading portion having a toner loading opening from which toner is loaded into the toner storing portion; a cap element which is able to hermetically close and open the toner loading opening; and a toner discharge port for discharging the toner stored in the toner storing portion out of the container, characterized in that the cap element is constructed so as to enclose the toner loading opening and be fastened by screw-fitting to the toner loading portion, and includes, as an engaging portion with the toner loading portion, a first projection capable of limiting the rotation of the cap element in a loosening direction; and the toner loading portion is formed at a first end side of the toner container and includes, as an engaging portion with the cap element, a second projection engaging the first projection and capable of limiting the rotation of the cap element in the loosening direction. 
   A toner container according to the second aspect is characterized in that, in addition to the configuration described in the above first aspect, the engagement between the first projection and the second projection is designed so that a stronger rotational force is needed when the engagement between the first projection and the second projection is released by rotating the cap element relative to the toner loading portion in the loosening direction than when the first projection and the second projection become engaged by rotating the cap element relative to the toner loading portion in the fastening direction. 
   A toner container according to the third aspect is characterized in that, in addition to the configuration described in the above first or second aspect, the toner discharge port is formed on a second end side that is opposite to the first end side where the toner loading portion of the toner container is formed, and is sealed by a sealing element bonded from without; the toner container includes a holder that encloses the outer periphery of the second end side where toner discharge port is formed and rotatably holds the toner container; and, the holder, when it encloses the second end side of the toner container, has an inner wall portion located opposing the toner discharge port that is hermetically closed by a sealing element. 
   A toner container according to the fourth aspect is characterized in that, in addition to the configuration described in any one the above first to third aspects, the container further includes an electric recording medium for storing information on the toner container, and the information can be read out in an image forming apparatus in which the toner container is set. 
   A toner container according to the fifth aspect of is characterized in that, in addition to the configuration described in the above fourth aspect, the information at least includes the number of times the toner container was recycled or the ID information of the toner being filled. 
   A toner loading method according to the sixth aspect is a toner loading method for loading toner into a toner container that includes: a cylindrical toner storing portion to be filled with toner; a toner loading portion having a toner loading opening from which toner is loaded into the toner storing portion; a cap element which is able to hermetically close and open the toner loading opening; and a toner discharge port for discharging the toner stored in the toner storing portion out of the container, and comprises the step of: loading toner into the toner storing portion of the toner container with the toner loading opening placed up; and suctioning air around the toner loading portion while toner is being loaded into the toner storing portion. 
   A toner loading method according to the seventh aspect is characterized in that, in addition to the configuration of the above sixth aspect, one of the toner containers described in the first to fifth aspects is used as the aforementioned toner container. 
   A toner container according to the first aspect is adapted to include: a cylindrical toner storing portion to be filled with toner; a toner loading portion having a toner loading opening from which toner is loaded into the toner storing portion; a cap element which is able to hermetically close and open the toner loading opening; and a toner discharge port for discharging the toner stored in the toner storing portion out of the container, and the cap element is constructed so as to enclose the toner loading opening and be fastened by screw-fitting to the toner loading portion. Accordingly, this configuration enables easy removal of the cap element from the toner container, hence it is possible to improve the work efficiency of the toner loading operation as well as to facilitate recycling of the toner container. 
   Further, the cap element includes, as an engaging portion with the toner loading portion, a first projection capable of limiting the rotation of the cap element in a loosening direction; and the toner loading portion is formed at a first end side of the toner container and includes, as an engaging portion with the cap element, a second projection engaging the first projection and capable of limiting the rotation of the cap element in the loosening direction. Accordingly, this configuration facilitates handling of the toner container without caring about toner leakage since the cap element will not come off unexpectedly due to a user&#39;s operational error. 
   In addition to the above common effect that is obtained from the first to seventh aspects, each aspect has the following effect. 
   Detailedly, according to the second aspect since the engagement between the first projection and the second projection is designed so that a stronger rotational force is needed when the engagement between the first projection and the second projection is released by rotating the cap element relative to the toner loading portion in the loosening direction than when the first projection and the second projection become engaged by rotating the cap element relative to the toner loading portion in the fastening direction, this configuration, in addition to the effect achieved by the first aspect, makes it possible to perform a locking operation with a smaller force when the cap element is closed after toner loading while it is possible to prevent the cap element from loosening and reliably keep its locked state even when it was attempted to rotate the cap element in its loosening direction by mistake. 
   The toner discharge port according to the third aspect is formed on a second end side that is opposite to the first end side where the toner loading portion of the toner container is formed, and is sealed by a sealing element bonded from without; the toner container includes a holder that encloses the outer periphery of the second end side where toner discharge port is formed and rotatably holds the toner container; and, the holder, when it encloses the second end side of the toner container, has an inner wall portion located opposing the toner discharge port that is hermetically closed by a sealing element. With this configuration, if the pressure of the loaded toner acts on the toner discharge port while toner is being loaded via the toner loading portion into the toner container, during transportation of the toner container or in other cases, the sealing element that seals the toner discharge port is supported by the inner wall portion. Accordingly, the sealing element that seals the toner discharge port will never peel off unexpectedly. Thus, in addition to the effect achieved by the first or second aspect it is possible to facilitate the toner loading operation as well as transportation of the toner container without causing any contamination on the operator and apparatus with spilt toner. 
   Since the toner container according to the fourth aspect further includes an electric recording medium for storing information on the toner container, and the information can be read out in an image forming apparatus in which the toner container is set, this configuration, in addition to the effect achieved by any one of the first to third aspects, facilitates confirmation of the usage history and recycled condition of the toner container being used. 
   Since the information according to the fifth aspect at least includes the number of times the toner container was recycled or the ID information of the toner being filled, this configuration, in addition to the effect achieved by fourth aspect, facilitates confirmation of the usage history and recycled condition of the toner container being used. 
   According to the sixth aspect, a toner loading method for loading toner into a toner container that includes: a cylindrical toner storing portion to be filled with toner; a toner loading portion having a toner loading opening from which toner is loaded into the toner storing portion; a cap element which is able to hermetically close and open the toner loading opening; and a toner discharge port for discharging the toner stored in the toner storing portion out of the container, comprises the step of: loading toner into the toner storing portion of the toner container with the toner loading opening placed up; and suctioning air around the toner loading portion while toner is being loaded into the toner storing portion. This configuration makes it possible to efficiently load the toner into the bottle from the toner loading opening without causing any contamination on the operator and apparatus with the toner spilt from the toner loading opening during toner loading. Hence, it is possible to markedly improve the work performance. 
   Since one of the toner containers described in the first to fifth aspects is used as the aforementioned toner container, this, in addition to the effect achieved by the sixth aspect, enables easy removal of the cap element from the toner container, thus making it possible to improve the work performance of the toner loading operation. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an illustrative view showing an overall configuration of an image forming apparatus using a toner container; 
       FIG. 2  is a schematic side sectional view showing a configuration of a developing unit and a toner supply device that constitute the image forming apparatus; 
       FIG. 3  is an overall front view showing the developing unit and toner supply device; 
       FIG. 4  is a perspective view showing the configuration of the developing unit; 
       FIG. 5  is a perspective view showing a mounting example when toner supply assemblies are set in toner supply assembly mounting mechanisms that constitute the toner supply devices; 
       FIG. 6  is a perspective view showing the configuration of the toner supply assembly mounting mechanisms; 
       FIG. 7A  is a side view showing a configuration of a toner supply assembly as a part of the toner supply device and  FIG. 7B  is its front view, viewed from the end face side of the toner supply assembly from which toner is supplied; 
       FIG. 8  is a side view of the front end part of a toner bottle as a part of the toner supply assembly; 
       FIG. 9  is a side view showing a configuration when scrapers for toner conveyance are fitted to the front end part of the toner bottle; 
       FIG. 10  is an illustrative view showing one example of the scrapers; 
       FIG. 11  is an illustrative view schematically showing a case where the scrapers are attached to the toner bottle; 
       FIG. 12  is a front view showing a configuration of the toner bottle; 
       FIG. 13  is an illustrative view showing a configuration of a sealing element that closes a bottle-side toner discharge port of the toner bottle; 
       FIG. 14A  is an illustrative view showing a state when the sealing element is fitted to the toner bottle;  FIG. 14B  is an illustrative view showing a state when the sealing element has been folded; 
       FIG. 15  is an illustrative view showing the positional relationship between the sealing element and scrapers; 
       FIG. 16  is an illustrative view showing a state where the sealing element has been fitted to a bottle holder; 
       FIG. 17  is an illustrative view showing a configuration of the rear end part of the toner bottle and a bottle cap; 
       FIG. 18  is a perspective view showing a configuration of the rear end part of the toner bottle and a bottle cap; 
       FIG. 19A  is a partial detailed view showing a structure of the engagement portion of the bottle cap with a toner loading portion;  FIG. 19B  is a partial detailed view showing a structure of the engagement portion of the toner loading portion with the bottle cap; 
       FIG. 20  is a perspective view showing another configurational example of the engagement portion between the toner bottle and bottle cap; 
       FIG. 21A  is a front view showing a configuration of a bottle holder that constitutes the toner supply device; 
       FIG. 21B  is a perspective view showing the bottle holder, when it is viewed from the rear side; 
       FIG. 22A  is a perspective view showing a first casing that constitutes the bottle holder,  FIG. 22B  is a perspective view showing a second casing that constitutes the bottle holder; 
       FIG. 23  is an illustrative view showing a positional relationship between a toner discharge chamber of the bottle holder and toner bottle&#39;s scrapers; 
       FIG. 24  is a schematic sectional view showing a configuration of the front end part of the toner bottle; 
       FIG. 25  is a plan view showing a configuration of a slip ring of the toner bottle; 
       FIG. 26  is a schematic sectional view showing the bottle holder attached to the front end part of the toner bottle; 
       FIG. 27A  is an illustrative view showing the bottle holder with its toner discharge port open,  FIG. 27B  is an illustrative view showing the bottle holder with the toner discharge port closed by a shutter mechanism; 
       FIG. 28  is an illustrative view showing the schematic structure of the rear side of the bottle holder; 
       FIG. 29A  is a perspective view showing the configuration of a shutter mechanism for a toner supply device in accordance with the present embodiment, when viewed from the front side, and  FIG. 29B  is a perspective view showing the shutter mechanism when viewed from the rear side; 
       FIG. 30A  is an illustrative view showing the relationship between the shutter mechanism and a first guide member of the bottle holder,  FIG. 30B  is an illustrative view showing the relationship between the shutter mechanism and the rotation of the toner bottle; 
       FIG. 31  is an illustrative view showing the structure of the toner supply assembly mounting mechanism; 
       FIG. 32  is an illustrative view showing the structure of a supply passage part for coupling the toner supply assembly mounting mechanism with a developing unit; 
       FIG. 33A  is an illustrative view showing the positional relationship between a regulating member and a projection piece before the toner supply device is mounted to a mount base;  FIG. 33B  is an illustrative view showing the positional relationship between the regulating member and the projection piece when the toner supply device has been mounted to the mount base; and  FIG. 33C  is an illustrative view showing the positional relationship between the regulating member and the projection piece when the toner supply device is dismounted from the mount base; 
       FIG. 34  is an illustrative view showing a schematic configuration of a device for loading toner into the toner bottle; and, 
       FIG. 35  is an illustrative view showing an overall configuration of a copier according to another embodiment. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The best mode for carrying out the present technology will be described with reference to the drawings. 
     FIG. 1  is an illustrative view showing an overall configuration of an image forming apparatus using a toner container. 
   As shown in  FIG. 1 , the present embodiment is applied to an image forming apparatus  1  in which developer images formed on photoreceptor drums  21  ( 21   a ,  21   b ,  21   c  and  21   d ) with developers (toners) which are supplied from developing rollers  231  ( 231   a ,  231   b ,  231   c  and  231   d ) in accordance with image data are transferred to a recording sheet by a transfer process, and includes toner supply devices  100  ( 100   a ,  100   b ,  100   c  and  100   d ) each having a toner bottle (toner container)  200  ( 200   a ,  200   b ,  200   c  or  200   d :  FIG. 3 ) for supplying toner to developing unit  23  so as to perform image output by automatic toner supply to the developing units  23  ( 23   a ,  23   b ,  23   c  and  23   d ). 
   As shown in  FIG. 1 , image forming apparatus according to the present embodiment includes: a plurality of process printing units (image forming means)  20  ( 20   a ,  20   b ,  20   c  and  20   d ) each having a photoreceptor drum  21  ( 21   a ,  21   b ,  21   c  or  21   d ) on which a developer image (which will be referred to as “toner image” hereinbelow) is formed with a developer (which will be referred to as “toner” hereinbelow) corresponding to the color of color-separated image information and a developing unit  23  ( 23   a ,  23   b ,  23   c  and  23   d ) for supplying the toner to the photoreceptor drum  21  surface; an exposure unit (light scanning device)  10  for creating electrostatic latent images on photoreceptor drums  21  of individual colors by illumination of laser beams in accordance with image information; a transfer belt unit  30  having an endless transfer belt  31  for conveying toner images; and a fixing unit  27  for thermally fixing the toner images transferred to recording paper, by means of a heat roller  27   a  and a pressing roller  27   b.    
   To begin with, the overall configuration of image forming apparatus  1  will be described. 
   As shown in  FIG. 1 , image forming apparatus  1  according to the present embodiment is a so-called digital color printer which is adapted to output a color image by separating image information into colors and forming images of individual colors, is mainly composed of an image forming portion  108  and a paper feed portion  109 , and forms multi-color images or monochrome images on recording paper in accordance with a print job sent from an information processor (not illustrated) such as a personal computer etc., externally connected. 
   Image forming portion  108  forms multi-color images based on electrophotography with yellow (Y), magenta (M), cyan (C) and black (BK) colors. This image forming portion is mainly composed of exposure unit  10 , process printing units  20 , fixing unit  27 , a transfer belt unit  30  having transfer belt  31  as a transfer means, transfer roller  36  and a transfer belt cleaning unit  37 . 
   In the overall arrangement of image forming portion  108 , fixing unit  27  is disposed on the top at one end side of a housing  1   a  of image forming apparatus  1 , transfer belt unit  30  is extended under the fixing unit  27  from one end side to the other end side of housing  1   a , process printing units  20  are disposed under the transfer belt unit  30 , and exposure unit  10  is disposed under the process printing units  20 . 
   Further, transfer belt cleaning unit  37  is arranged on the other end side of transfer belt unit  30 . Also, a paper output tray  43  is arranged contiguous to fixing unit  27 , over image forming portion  108 . Paper feed portion  109  is arranged under the image forming portion  108 . 
   In the present embodiment, as process printing units  20 , four process printing units  20   a ,  20   b ,  20   c  and  20   d , corresponding to individual colors, i.e., black (BK), cyan (C), magenta (M) and yellow (Y) are arranged sequentially along transfer belt  31 . 
   These process printing units  20 ( 20   a ,  20   b ,  20   c  and  20   d ) are arranged in parallel to each other, in the approximately horizontal direction (in the left-to-right direction in the drawing) in housing  1   a , and include respective photoreceptor drums  21  ( 21   a ,  21   b ,  21   c  and  21   d ) as the image support for each individual associated color, respective chargers (charging means)  22  ( 22   a ,  22   b ,  22   c  and  22   d ) for charging the photoreceptor drums  21 , respective developing units (developing means)  23  ( 23   a ,  23   b ,  23   c  and  23   d ) and respective cleaner units  24  ( 24   a ,  24   b ,  24   c  and  24   d ) and other components. 
   Here, the symbols a, b, c, and d added to the constituents for individual colors show correspondence to black (BK), cyan (C), magenta (M) and yellow (Y) respectively. In the description hereinbelow, however, the constituents provided for each color are generally referred to as photoreceptor drum  21 , charger  22 , developing unit  23 , and cleaner unit  24 , except in the case where the constituents corresponding to a specific color need to be specified and described. 
   Photoreceptor drum  21  is arranged so that part of its outer peripheral surface comes into contact with the surface of transfer belt  31  while charger  22  as an electric field generator, developing unit  23  and cleaner unit  24  are arranged along, and close to, the outer peripheral surface of the drum. 
   As charger  22 , a corona-wire charger is used and arranged, at a position on the approximately opposite side across photoreceptor drum  21 , from transfer belt unit  30  and close to the outer peripheral surface of photoreceptor drum  21 . Though in the present embodiment a corona-wire charger is used as charger  22 , any type of charger can be used without limitation, in place of the corona-wire charger, such as a fur brush type charger, magnetic brush type charger, roller-type charger, saw-toothed type charger, ion-generation charging device etc., as long as it can provide the desired charge performance to the photoreceptor drum. 
   Developing units  23   a ,  23   b ,  23   c  and  23   d  hold associated toners of black (BK), cyan (C), magenta (M) and yellow (Y) colors, each developing unit  23  being arranged on the downstream side of charger  22  with respect to the rotational direction of the photoreceptor drum (in the direction of arrow A in the drawing). 
   In developing units  23   a ,  23   b ,  23   c  and  23   d , in order to deal with high-speed and large-volume printing, toner supply devices  100   a ,  100   b ,  100   c  and  100   d  equipped with five toner supply assemblies  500   a ,  500   b ,  500   c  and  500   d  for supplying developers to respective developing units  23   a ,  23   b ,  23   c  and  23   d  are provided. Developing rollers  231   a ,  231   b ,  231   c  and  231   d  are arranged opposing respective photoreceptor drums  21   a ,  21   b ,  21   c  and  21   d , so as to supply the associated colors of toners to the electrostatic latent images formed on the outer peripheral surfaces of photoreceptor drums  21   a ,  21   b ,  21   c  and  21   d , respectively to visualize them. 
   As the toner to be supplied, toners of black (BK), cyan (C), magenta (M) and yellow (Y) colors are stored in toner supply assemblies  500   a ,  500   b ,  500   c  and  500   d , respectively. 
   Here, two toner supply assemblies  500   a  for black (BK) toner are arranged side by side in order to support large-volume printing, taking into account the practice that monochrome printing is usually used most frequently. 
   Each toner supply assembly  500  is arranged at a position approximately directly above the developing unit  23  for performing development with the corresponding toner, and is connected to the corresponding developing unit  23  by means of a toner supply passage part  612  ( 612   a ,  612   b ,  612   c  or  612   d ). 
   Here, supply passage part  612   a  for supplying the black (BK) toner is constructed so that the toner from two toner supply devices  100   a  and  100   a  can be put together and supplied to developing unit  23   a.    
   Cleaner unit  24  is arranged on the upstream side of charger  22  with respect to the rotational direction of the photoreceptor drum. Cleaner unit  24  has a cleaning blade  241  and is configured so that the cleaning blade  241  is positioned in abutment with the outer peripheral surface of photoreceptor drum  21  so as to scrape and collect the leftover toner off the photoreceptor drum  21 . A reference numeral  242  in the drawing designates a conveying screw for conveying the collected toner. 
   In the present embodiment, cleaning blade  241  is used but the cleaning unit is not limited to this configuration. One or more cleaning blades may be used or a fur-brush or magnetic brush may be used alone. Alternatively, a fur-brush or magnetic brush may be used in combination with a cleaning blade. That is, any configuration may be used as long as it can scrape and collect the leftover toner off the photoreceptor drum  21 . 
   Exposure unit  10  is mainly composed of a box-shaped housing, a laser scanning unit (LSU)  11  having a laser illuminator  11   a  incorporated therein, a polygon mirror  12  and reflection mirrors  13   a ,  13   b ,  13   c ,  13   d ,  14   a ,  14   b  and  14   c  etc. for reflecting the laser beams for associated colors. 
   The laser beam emitted from the laser illuminator of laser scanning unit  11  is separated into color components by polygon mirror  12  and an unillustrated f-θ lens, then the separated components of light are reflected by reflection mirrors  13   a  to  13   d  and  14   a  to  14   c  to illuminate the respective photoreceptor drums  21   a ,  21   b ,  21   c  and  21   d  of individual colors. 
   Here, concerning laser scanning unit  11 , a writing head made up of an array of light emitting devices such as EL (electro luminescence), LED (light emitting diode) and others, may be used instead of the laser illuminator. Also, a light source in combination with a liquid crystal shutter may be used. That is, any configuration can be used as long as it can create an electrostatic latent image on the photoreceptor drum  21  surface. 
   As shown in  FIG. 1 , transfer belt unit  30  is essentially composed of transfer belt  31 , a transfer belt drive roller  32 , a transfer belt driven roller  33  and intermediate transfer rollers  35   a ,  35   b ,  35   c  and  35   d.    
   In the following description, any of intermediate transfer rollers  35   a ,  35   b ,  35   c  and  35   d  will be referred to as intermediate transfer roller  35  when general mention is made. 
   Transfer belt  31  is formed of an endless film of about 75 μm to 120 μm thick. Transfer belt  31  is essentially made from polyimide, polycarbonate, thermoplastic elastomer alloy or the like. 
   Also, transfer belt  31  is tensioned by transfer belt drive roller  32 , transfer belt driven roller  33  and intermediate transfer rollers  35  so that its surface comes into contact with the outer peripheral surfaces of photoreceptor drums  21 , and is adapted to move in the auxiliary scan direction (in the direction of arrow B in the drawing) by the driving force of the transfer belt drive roller  32 . 
   Transfer belt drive roller  32  is disposed at one end side of housing  1   a  and drives the transfer belt  31  by applying a driving force to transfer belt  31  whilst nipping and pressing the transfer belt  31  and a recording sheet together between itself and transfer roller  36  to convey the recording sheet. 
   Transfer belt driven roller  33  is disposed on the other end side of housing  1   a , so as to suspend and tension the transfer belt  31  approximately horizontally from the fixing unit  27  side to the other end side of housing  1   a , in cooperation with transfer belt drive roller  32 . However, if the dimension in the width direction of image forming apparatus  1  in  FIG. 1  needs to be smaller, that is, if the foot print is made smaller with respect to the width direction in order to achieve space-saving, the position of transfer belt drive roller  32  may be displaced so that transfer belt  31  is inclined in either way from the fixing unit  27  side to the other of housing  1   a  while the photoreceptors, developing units, laser illuminator, fixing unit and other components may be rearranged and resized as appropriate in association with that change in layout. 
   Intermediate transfer rollers  35  are arranged in the interior space of transfer belt  31  wound between transfer belt drive roller  32  and transfer belt driven roller  33  and positioned with their axes displaced relative to corresponding photoreceptor drums  21 , in the lateral direction in the drawing, to the downstream side with respect to the moving direction of transfer belt  31 , so as to press the inner surface of transfer belt  31  and bring its outer peripheral surface into contact with part of the outer peripheral surface of each photoreceptor drum  21 , forming a predetermined amount of nip. 
   Further, intermediate transfer roller  35  is formed of a metal (e.g., stainless steel) shaft having a diameter of 8 to 10 mm and a conductive elastic material such as EPDM, foamed urethane etc., coated on the outer peripheral surface of the metal shaft. However, the configuration should not be limited to use of these elastic materials. 
   The thus formed intermediate transfer roller  35  is applied with a high-voltage transfer bias for transferring the toner image formed on photoreceptor drum  21  to transfer belt  31 , i.e., a high voltage of a polarity (+) opposite to the polarity (−) of the electrostatic charge on the toner, so as to apply a uniform high voltage from the elastic material to transfer belt  31 . 
   The visualized toner images (electrostatic images) formed on the photoreceptor drums  21  correspondingly to respective colors are transferred one over another on transfer belt  31 , reproducing the image information that has been input to the apparatus. The thus formed laminated image information is transferred to the recording sheet by transfer roller  36  disposed at its contact point with transfer belt  31 . 
   Transfer roller  36  as a constituent of the transfer means is a means for transferring the toner image transferred to transfer belt  31  to recording paper, and is arranged opposing transfer belt drive roller  32  at approximately the same level and in parallel thereto and pressing against the transfer belt  31  wound on the transfer belt driver roller  32 , forming a predetermined nip therewith while being applied with a high voltage of a polarity (+) opposite to the polarity (−) of the static charge on the toner, for transferring the multi-color toner image formed on the transfer belt  31  to the recording paper. 
   In order to produce a constant nip between transfer belt  31  and transfer roller  36 , either transfer belt drive roller  32  or transfer roller  36  is formed of a hard material such as metal or the like while the other roller is formed of a soft material such as elastic rubber, foamed resin, etc. 
   A registration roller  26  is provided under transfer belt drive roller  32  and transfer roller  36 . This registration roller  26  is configured so as to deliver the recording sheet that is fed from paper feed portion  109  toward the transfer roller  36  side by aligning the front end of the sheet with the leading end of the toner image on transfer belt  31 . 
   Since the toner adhering to transfer belt  31  as the belt comes in contact with photoreceptor drums  21 , or the toner which has not been transferred to the recording sheet by transfer roller  36  and remains on transfer belt  31 , would cause color contamination of toners at the next operation, transfer belt cleaning unit  37  is adapted to remove and collect such toner. 
   Transfer belt cleaning unit  37  includes: a cleaning blade  37   a , located near transfer belt driven roller  33  and arranged so as to abut (come into sliding contact with) transfer belt  31 ; and a box-like toner collector  37   b  for temporarily holding the left over toner, remained on and scraped from transfer belt  31  by the cleaning blade  37   a , to thereby scrape and collect the leftover toner off the transfer belt  31  surface. 
   Also, transfer belt cleaning unit  37  is arranged near process printing unit  20   a , on the upstream side of the process printing unit  20   a  with respect to the moving direction of transfer belt  31 . Further, transfer belt  31  is supported from its interior side by transfer belt driven roller  33 , at the portion where cleaning blade  37   a  comes into contact with the outer surface of transfer belt  31 . 
   Fixing unit  27  includes: as shown in  FIG. 1 , a pair of fixing rollers  271  consisting of a heat roller  27   a  and pressing roller  27   b ; and a conveying roller  27   c  above the fixing rollers  271 . A recording sheet is input from below fixing rollers  271  and output upward towards conveying roller  27   c.    
   Above fixing unit  27  a paper discharge roller  28  is arranged so that the recording sheet conveyed from conveying roller  27   c  is discharged by the paper discharge roller  28  onto paper output tray  43 . 
   Referring to the fixing of a toner image by fixing unit  27 , a heating device (not shown) such as a heater lamp or the like, provided inside or close to heat roller  27   a  is controlled based on the detected value from a temperature detector (not shown) so as to keep heat roller  27   a  at a predetermined temperature (fixing temperature) while the recording sheet with a toner image transferred thereon is heated and pressed between heat roller  27   a  and pressing roller  27   b  as it is being conveyed and rolled thereby, so that the toner image is thermally fused onto the recording sheet. 
   A duplex printing paper path S 3  for double-sided printing is constructed adjacent to fixing unit  27 , from the rear side of fixing unit  27  downward to the vicinity of paper feed portion  109 . Conveying rollers  29   a  and  29   b  are arranged at the top and bottom and along the duplex printing paper path S 3 , thereby the recording sheet is inverted and delivered again toward transfer roller  36 . 
   Specifically, conveying roller  29   a  is disposed at the rear of fixing unit  27  and conveying roller  29   b  is located, below conveying roller  29   a  with respect to the top and bottom direction, and at approximately the same level as registration roller  26 . 
   In the present embodiment, heat roller  27   a  using a heating means made up of a heater lamp etc., is used with pressing roller  27   b , but an induction heating type heating means may be used alone or in combination. Further, it is not necessary to use a roller as a means for applying pressure. That is, any appropriate method can be used as long as it can uniformly fix the toner image to the paper with heat without causing any image disturbance. 
   Paper feed portion  109  includes a manual feed tray  41  and paper feed cassette  42  for holding recording paper to be used for image forming, and is adapted to deliver recording paper, sheet by sheet, from manual feed tray  41  or paper feed cassette  42  to image forming portion  108 . 
   As shown in  FIG. 1 , manual feed tray  41  is arranged at one side end (on the right side in the drawing) of housing  1   a  of image forming apparatus  1  so that it can be unfolded outside when used and folded up to the one end side when unused. This tray delivers paper, sheet by sheet, into the housing  1   a  of image forming apparatus  1  when the user places a few recording sheets (necessary number of sheets) of a desired type. 
   Arranged inside housing  1   a  of image forming apparatus  1  on the downstream side with respect to the manual feed tray  41 &#39;s paper feed direction of recording paper (the direction of arrow C in the drawing) is a pickup roller  41   a  at the side of exposure unit  10 . A conveying roller  41   b  is also disposed at approximately the same level further downstream with respect to the paper feed direction. 
   Pickup roller  41   a  touches one edge part of the surface of the recording sheet that is fed from manual feed tray  41  and reliably conveys the paper, sheet by sheet, by the function of roller&#39;s frictional resistance. 
   The aforementioned pickup roller  41   a  and conveying rollers  41   b ,  41   c  and  41   d  constitute a recording paper conveying path S 1 . 
   On the other hand, paper feed cassette  42  is arranged under the image forming portion  108  and exposure unit  10  in housing  1   a , so as to accommodate a large amount of recording sheets of a size specified by the specification of the apparatus or of a size that is determined beforehand by the user. 
   Arranged above one end side (the left-hand side in the drawing) of paper feed cassette  42  is a pickup roller  42   a . A conveying roller  42   b  is also provided on the downstream side of the pickup roller  42   a  with respect to the pickup roller  42   a &#39;s feed direction of recording paper. 
   Pickup roller  42   a  touches one edge part of the surface of the topmost sheet of the recording sheets set on the paper feed cassette  42  in response to a printout request and reliably picks up and feeds the paper, sheet by sheet, by the function of roller&#39;s frictional resistance. 
   Conveying roller  42   b  conveys the recording sheet delivered from pickup roller  42   a  upward along a recording sheet feed path S 2  formed on one end side inside housing  1   a  to image forming portion  108 . 
   Next, image output by image forming apparatus  1  of the present embodiment will be described. 
   Image forming apparatus  1  is constructed so as to transfer the toner images formed on photoreceptor drums  21  to a recording sheet fed from paper feed portion  109  by a so-called intermediate transfer process (offset process) via transfer belt  31 . 
   First, charger  22  uniformly electrifies the outer peripheral surface of photoreceptor drum  21  at a predetermined voltage. Each electrified photoreceptor drum  21  is irradiated with a laser beam from exposure unit  10 , so that an electrostatic latent image for each color is formed on the photoreceptor drum  21  for the color. 
   Next, toner is supplied from developing units  23  ( 23   a ,  23   b ,  23   c  and  23   d ) to the outer peripheral surfaces of photoreceptor drums  21  ( 21   a ,  21   b ,  21   c  and  21   d ) so that the static latent images formed on the outer peripheral surfaces of photoreceptor drums  21  are visualized with toner so as to form toner images. 
   Then, the toner images formed on photoreceptor drums  21  are transferred to transfer belt  31 . 
   Transfer of the toner image from photoreceptor drum  21  to transfer belt  31  is done by application of a high voltage from intermediate transfer roller  35  arranged in contact with the interior side of transfer belt  31 . 
   As intermediate transfer roller  35  is applied with a high voltage of a polarity (+) opposite to that of the polarity (−) of the electrostatic charge on the toner, transfer belt  31  has a high potential uniformly applied by the intermediate transfer roller  35 , presenting the opposite polarity (+). Thereby, the toner image bearing negative (−) charge on photoreceptor drum  21  is transferred to transfer belt  31  as the photoreceptor drum  21  turns and comes into contact with transfer belt  31 . 
   The toner images of colors formed on respective photoreceptor drums  21  are transferred to transfer belt  31 , laid over, one over another, in the order of yellow (Y), magenta (M), cyan (C) and black (BK) as transfer belt  31  moves to come into contact with each of the rotating photoreceptor drums  21 , forming a color toner image on transfer belt  31 . 
   In this way, the toner images developed from static latent images on photoreceptor drums  21  for every color, are laminated on transfer belt  31  so that the image for printing is reproduced as a multi-color toner image on transfer belt  31 . 
   Then, as transfer belt  31  moves and reaches the position where the recording sheet and the transfer belt  31  meet, the multi-color toner image having been transferred on transfer belt  31  is transferred from transfer belt  31  to the recording sheet by the function of transfer roller  36 . 
   Since the toner adhering to transfer belt  31  as the belt comes in contact with photoreceptor drums  21 , or the toner which has not been transferred to the recording sheet by the function of transfer roller  36  and remains on transfer belt  31 , would cause color contamination of toners at the next operation, it is removed and collected by transfer belt cleaning unit  37 . 
   Next, the operation of feeding recording sheets by paper feed portion  109  will be described. 
   When the recording paper placed on manual feed tray  41  is used, as shown in  FIG. 1  the paper is taken in by pickup roller  41   a  from manual feed tray  41 , sheet by sheet, at controlled timings in accordance with the instructions from a control panel (not shown), and fed into the machine. 
   The recording sheet thus taken into the machine is conveyed along recording paper feed path S 1  by conveying roller  41   b  to image forming portion  108 . 
   When the recording paper accommodated in paper feed cassettes  42  is used, the paper is separated and fed from paper feed cassette  42 , sheet by sheet, by pickup roller  42   a  in accordance with a printout request and conveyed by conveying roller  42   b  along recording paper feed path S 2  to image forming portion  108  located above. 
   The recording sheet conveyed from manual feed tray  41  or paper feed cassette  42  is delivered to the transfer roller  36  side, by registration roller  26 , at such a timing as to bring the front end of the recording sheet in register with the leading end of the toner image on transfer belt  31 , so that the toner image on transfer belt  31  is transferred to the recording sheet. 
   The recording sheet with the toner image transferred thereon is conveyed approximately vertically and reaches fixing unit  27 , where the toner image is thermally fixed to the recording sheet by heat roller  27   a  and pressing roller  27   b.    
   When one-sided printing is requested, the recording sheet having passed through fixing unit  27  is discharged by discharge roller  28  and placed facedown on paper output tray  43 . 
   In contrast, when double-sided printing is requested, the recording sheet is stopped and nipped at paper discharge roller  28 , then the paper discharge roller  28  is rotated in reverse so that the recording sheet is guided to duplex printing paper path S 3  and conveyed again to registration roller  26  by conveying rollers  29   a  and  29   b.    
   By this movement, the printing face of the recording sheet is inverted and the direction of conveyance is reversed. Illustratively, the leading edge of the sheet at the first printing is directed to the trailing end when the underside is printed, or the trailing edge of the sheet at the first printing is directed to the leading end when the underside is printed. 
   After the toner image is transferred and thermally fixed to the underside of the recording sheet, the sheet is discharged onto paper output tray  43  by paper discharge roller  28 . 
   Thus, the transfer operation to recording paper is performed. 
   Next, the configuration of developing unit  23  and toner supply device  100  according to the present embodiment will be described in detail with reference to the drawings. 
     FIG. 2  is a schematic side sectional view showing a configuration of a developing unit and a toner supply device that constitute an image forming apparatus of the present embodiment;  FIG. 3  is an overall front view showing the configuration of the developing unit and toner supply device;  FIG. 4  is a perspective view showing the configuration of the developing unit mounted to the image forming apparatus according to the present embodiment;  FIG. 5  is a perspective view showing a mounting example when toner supply assemblies are set in a toner supply assembly mounting mechanisms that constitute the toner supply devices according to the present embodiment; and  FIG. 6  is a perspective view showing a configuration of the toner supply assembly mounting mechanisms. 
   To begin with, developing unit  23  will be described. 
   As shown in  FIGS. 2 and 3 , in developing unit  23 , a toner input port  234   a  for leading the toner is formed as an opening at the top of a casing  234  that forms its exterior. The developing unit incorporates inside casing  234  a developing roller  231 , a first toner conveying roller  232  and a second toner conveying roller  233 , and is mounted to the image forming apparatus body with the developing roller  231  opposed, in abutment with, or close to, photoreceptor drum  21 . This toner input port  234   a  of developing unit  23  is formed at a position further outside of the width W of the transfer belt, on the same side as a toner feed port  611  of a toner supply assembly mounting mechanism  600  is disposed. 
   First toner conveying roller  232  and second toner conveying roller  233  are disposed in the bottom of casing  234  in parallel with each other along the axis direction of developing roller  231  so that the toner that is fed into casing  234  is agitated with the developer and conveyed to developing roller  231 . Developing roller  231  is arranged over and above first toner conveying roller  232  so as to be exposed from an opening mouth  235 . 
   Casing  234  is a box-shaped configuration elongated in the direction (the width direction of the transfer belt) perpendicular to the direction of transfer (the transfer belt&#39;s direction of movement) when mounted in the image forming apparatus body, and is formed with opening mouth  235  so that developing roller  231  therein opposes photoreceptor drum  21  when developing unit  23  is mounted to the image forming apparatus body. 
   Opening mouth  235  is made open long across the width of casing  234  along the axis direction of developing roller  231  so that at least developing roller  231  will be able to oppose and abut photoreceptor drum  21 . Provided along the bottom edge of opening mount  235  in the drawing is a blade  236  that extends in the axis direction of developing roller  231 . Blade  236  is positioned so as to create a predetermined clearance between the blade  236  edge and the developing roller  231  surface, whereby a predetermined amount of toner can be supplied to the developing roller  231  surface through this clearance. 
   Arranged over the thus constructed developing unit  23  is toner supply device  100  ( FIGS. 2 and 3 ). 
   Referring next to the drawings, the configuration of toner bottle  200  and toner supply device  100  according to the present embodiment will be described. 
     FIG. 7A  is a side view showing a configuration of a toner supply assembly as a part of the toner supply device according to the present embodiment;  FIG. 7B  is a front view of the toner supply assembly, viewed from the end face side from which toner is supplied;  FIG. 8  is a side view of the front end part of a toner bottle as a part of the toner supply assembly;  FIG. 9  is a side view showing a configuration when scrapers for toner conveyance are fitted to the front end part of the toner bottle;  FIG. 10  is an illustrative view showing one example of the scrapers;  FIG. 11  is an illustrative view schematically showing a case where the scrapers shown in  FIG. 10  are fitted to the toner bottle; and  FIG. 12  is a front view showing a configuration of the toner bottle. 
   In the present embodiment, any of toner supply assemblies  500   a ,  500   b ,  500   c  and  500   d  for respective toner supply devices  100  ( 100   a ,  100   b ,  100   c  and  100   d ) mounted in image forming apparatus  1  is assumed to have an identical configuration. 
   As shown in  FIGS. 2 and 7A , toner supply device  100  is mainly composed of a toner bottle (toner container)  200  that is filled with toner as a developer, a toner supply assembly  500  having a bottle holder (toner container holder)  300  that rotatably holds the toner bottle  200  at its one end, and a toner supply assembly mounting mechanism (toner feed device)  600  to which the toner supply assembly  500  is mounted so as to feed toner to developing unit  23 . 
   Provided on the bottom of bottle holder  300  (the lower side when toner supply device  100  is mounted in image forming apparatus  1 ) is a shutter mechanism  400  for opening and closing an aftermentioned toner discharge port for discharging the toner fed from toner bottle  200  to the outside of bottle holder  300 , as shown in  FIG. 7B . 
   Illustratively, when the toner discharge port of bottle holder  300  is opened by shutter mechanism  400 , the toner discharge port and supply passage part  612  as a part of toner supply assembly mounting mechanism  600  are connected to each other so that the toner supplied from toner bottle  200  is fed to developing unit  23  by way of supply passage part  612  that is connected to developing unit  23 . 
   To begin with, toner bottle  200  which is the characteristic part in the present embodiment will be described. 
   As shown in  FIG. 7A , toner bottle  200  is comprised of a main part (toner storing portion)  201  having an approximately cylindrical shape. When the end of main part  201  on the side supported by bottle holder  300  is called a front end part  201   a , this front end part  201   a  is formed with an opening (described later) for discharging toner. 
   Formed on the peripheral side of main part  201  are a plurality of slots  201   c  which are depressed towards the rotational axis X. Here, on the interior side of main part  201 , the parts corresponding to slots  201   c  form ribs that are projected towards the rotational axis X side. 
   The grooves formed between these ribs function as guide grooves for guiding the toner stored in main part  201  from rear end part  201   b  toward front end part  201   a.    
   Herein, slots  201   c  are spirally formed as shown in  FIG. 7A  or inclined so that they move toward front end part  201   a  when main part  201  rotates about the rotational axis X clockwise viewed from the front end side (in the Y-direction). With this configuration, as toner bottle  200  rotates in the Y-direction, the toner held in the toner bottle  200  can be conveyed from rear end part  201   b  to front end part  201   a  of main part  201 . 
   Here, slots  201   c  may have any shape as long as they can convey the toner stored in main part  201  from rear end part  201   b  toward front end part  201   a.    
   As shown in  FIG. 8 , front end part  201   a  is formed to be a cylindrical shape having a smaller diameter than that of the central part of main part  201 . A pair of ribs  202 ,  202  are projected outward from the front end face  201   d  of front end part  201   a.    
   These ribs  202 ,  202  are adapted to be engaged with an actuator of an unillustrated drive when toner supply device  100  is mounted to image forming apparatus  1 . With this arrangement, a drive force from the actuator is transferred by way of ribs  202  and  202  to toner bottle  200  of toner supply device  100  so that it is rotated. 
   As shown in  FIGS. 9 and 10 , peripheral surface  201   e  of front part end  201   a  is formed with a toner conveying means  206  which is constructed of a plurality of scrapers (toner conveyors)  203  for conveying toner and a fixing member (toner conveyor attachment)  204  on which scrapers  203  are integrally fixed. 
   Scrapers  203  are each formed of a plate-like elastic resin such as rubber etc, and arranged approximately radially outwards and equi-angularly at eight positions on the peripheral surface of fixing member  204 , as shown in  FIGS. 10 to 12 . Each scraper  203  is formed in an inverted, approximately open-V section with its free end side bent to the upstream side (to the rear) with respect to the rotational direction (the direction indicated by arrow D in  FIG. 12 ) of toner bottle  200 . 
   In the present embodiment, the part of scraper  203 , extending radially from fixing member  204  functions as a toner conveying portion  203   a  and the part that is flexed to the upstream side (rear side) with respect to the rotational direction of toner bottle  200  functions as a lid portion  203   b.    
   Toner conveying portion  203   a  is formed longer than the size of the toner conveyance space in bottle holder  300 , so that, when toner conveying means  206  fitted on toner bottle  200  is assembled inside bottle holder  300  and the toner bottle  200  is rotated the free end side of the scraper is tilted to the upstream side (rearwards) with respect to the toner bottle&#39;s direction of rotation (see  FIGS. 21A and 21B ). 
   This arrangement is aimed at scraping out the toner that is accumulated in toner discharge chamber  300   d  ( FIG. 23 ) efficiently. However, if the length of toner conveying portion  203   a  of scraper  203  is too long, its friction with the inner peripheral surface of bottle holder  300  becomes greater, causing increase in rotational load. Accordingly, it is preferred that the length of the toner conveying portion is set at a size that will not cause sharp increase of the rotational load. 
   Lid portion  203   b  is formed so that the length W 2  that comes into sliding contact with the inner peripheral surface of bottle holder  300  is longer than the opening length W 1  of toner discharge port  300   b . That is, lid portion  203   b  is constructed so as to completely cover the opening of toner discharge port  300   b  when it opposes toner discharge port  300   b  (see  FIGS. 21A and 21B ). 
   The opening angle between toner conveying portion  203   a  and lid portion  203   b  is set so that θ 1 &gt;θ 2 , where θ 1  is the angle when scraper  203  shown in  FIG. 10  is set free and θ 2  is the angle when scraper  203  is assembled inside bottle holder  300  ( FIG. 21A ). The difference in opening angle makes it possible to bring lid portion  203   b  into close contact with toner discharge port  300   b  by the repulsive force of scraper  203 . 
   As shown in  FIG. 10 , fixing member  204  has an annular shape, made up of a material having elasticity (a general elastic resin such as rubber etc.), having an inside diameter marginally smaller than the outside diameter of front end part  201   a  ( FIG. 9 ) and being formed with projections  204   a  ( FIG. 10 ) on the inner peripheral surface thereof. 
   These projections  204   a  are adapted to fit into cutouts  201   f  that are previously formed on the front end part  201   a , as shown in  FIG. 11 . 
   In the present embodiment, use of this fixing member  204  makes it simple to arrange scrapers  203  on main part  201  by enlarging the ring part slightly and setting it on peripheral surface  201   e  ( FIG. 8 ) of front end part  201   a . Moreover, it is possible to reliably fix fixing member  204  to front end part  201   a  by fitting projections  204   a  of fixing member  204  into cutouts  201   f  formed on peripheral surface  201   e  of front end part  201   a . That is, this arrangement enables fixing member  204  to be driven integrally with front end part  201   a  without it running idly over peripheral surface  201   e  of front end part  201   a.    
   Here, scrapers  203  may be directly provided on peripheral surface  201   e  of front end part  201   a.    
   Formed on an end face  201   g  that forms a step with front end part  201   a  in main part  201  is a bottle-side toner discharge port (toner discharge port)  201   h  for discharging the toner held in main part  201 , as shown in  FIG. 12 . 
   Here, in the present embodiment, this bottle-side toner discharge port  201   h  is formed in an essentially rectangular shape, but the opening of the discharge port should not be limited to this and may have an approximately square-shaped, polygonal, circular or any other shaped configuration as long as it will not hinder discharge of toner. 
   Further, as shown in  FIG. 12 , scraper  203  is adjusted and positioned at a predetermined angle α with the center of bottle-side toner discharge port  201   h  when fixing member  204  is attached to the bottle. 
   Here, scrapers  203  are preferably disposed at positions so as not to disturb toner discharge from bottle-side toner discharge port  201   h . As long as this condition is satisfied, any angle can be selected as angle α. In order to reliably prevent failures of toner discharge from bottle-side toner discharge port  201   h , angle α is preferably set at 90 deg. 
   The toner discharged from bottle-side toner discharge port  201   h  is collected inside bottle holder  300  that is provided so as to cover front end part  201   a . Bottle holder  300  is formed with the toner discharge port for discharging the collected toner. 
   As shown in  FIG. 12 , bottle-side toner discharge port  201   h  is temporarily closed by a sealing element  220  until directly just before the operation of supplying toner to developing unit  23  is started as toner bottle  200  rotates. 
   Sealing element  220  is formed of a flexible material and is configured so that it peels off toner bottle  200  by rotation of the toner bottle  200  to thereby release bottle-side toner discharge port  201   h.    
   Now, sealing element  220  will be described in detail with reference to the drawings. 
     FIG. 13  is an illustrative view showing a configuration of the sealing element that closes the bottle-side toner discharge port of a toner bottle according to the present embodiment;  FIG. 14A  is an illustrative view showing a state when the sealing element is fitted to the toner bottle;  FIG. 14B  is an illustrative view showing a state when the sealing element has been folded;  FIG. 15  is an illustrative view showing the positional relationship between the sealing element and scrapers; and,  FIG. 16  is an illustrative view showing a state where the sealing element has been fitted to the bottle holder. 
   Sealing element  220  is formed of a product of DuPont Kabushiki Kaisha “Tyvek®”, a felt made of extra fine polyethylene fibers, which is air-permeable and presents good slidability. The sealing element is, as shown in  FIGS. 13 and 14A , is formed in an approximately arc shape having a predetermined width and covering an angular range of about 180 degrees along the toner bottle&#39;s peripheral direction over end face  201   g  of toner bottle  200  on which bottle-side toner discharge port  201   h  is formed. 
   As shown in  FIG. 14A , sealing element  220  is arranged so that its first end  220   a  is bonded to end face  201   g  of toner bottle  200  so as to cover and seal bottle-side toner discharge port  201   h  while second end  220   b  is bonded to an aftermentioned wall portion  301   c  ( FIGS. 16 and 22A ) formed inside bottle holder  300 . 
   Further, as shown in  FIG. 14B , sealing element  220  is laid out between end face  201   g  and scrapers  203  as shown in  FIG. 15  and folded at the approximate center of the arc over end face  201   g  of toner bottle  200  so that its fold  220   c  is located on the downstream side (front side) of the folded second end  220   b  with respect to the toner bottle&#39;s direction of rotation. 
   Also, as shown in  FIGS. 14 and 16 , bottle-side toner discharge port  201   h  that is hermetically closed by sealing element  220  is set at such a position as to oppose wall portion (inner wall portion)  301   c  of bottle holder  300 , so that toner bottle  200  is positioned and held temporarily by the sealing element  220 . 
   In the present embodiment, toner bottle  200  to which sealing element  220  is bonded is adapted to be fixed when this sealing element  220  is fixed to bottle holder  300 . 
   With this arrangement, since sealing element  220  is disposed opposing wall portion  301   c  of bottle holder  300 , if a pressure due to falling toner acts on sealing element  220  of bottle-side toner discharge port  201   h  when toner is charged into main part  201  of toner bottle  200 , the toner&#39;s pressure can be received by wall portion  301   c . As a result it is possible to perform toner loading without making sealing element  220  peel off. 
   Sealing element  220 &#39;s first end  220   a  that is bonded to the toner bottle  200  side is adhered to toner bottle  200 &#39;s end face  201   g  by thermal fusing heat seal while second end  220   b  that is bonded to the bottle holder  300  side is adhered to wall portion  301   c  of bottle holder  300  with an adhesive such as double-sided tape. The adhesive strength with which second end  220   b  is adhered to the bottle holder  300  side is specified to be greater than the adhesive strength with which first end  220   a  is adhered to the toner bottle  200  side. 
   Second end  220   b  of sealing element  220  is fixed to bottle holder  300  by making an acute angle to the wall portion  301   c , as shown in  FIG. 16 . 
   With this arrangement, when sealing element  220  is peeled off by rotation of toner bottle  200 , toner bottle  200  turns in the direction of arrow D and second end  220   b  of sealing element  220  is pulled in the direction along the wall portion  301   c , thus second end  220   b  is adapted to be unlikely peeled off wall portion  301   c.    
   On the other hand, since first end  220   a  of sealing element  220  is pulled in the direction approximately 180 degrees opposite to end face  201   g  of toner bottle  200 , first end  220   a  is easy to be peeled off end face  201   g.    
   With the above operation, since first end  220   a  can be easily peeled off end face  201   g  of toner bottle  200  while second end  220   b  that is bonded to wall portion  301   c  of bottle holder  300  will not come off, it is possible to simply open bottle-side toner discharge port  201   h  as toner bottle  200  is rotated. 
   Further, since sealing element  220 , after it has been separated from toner bottle  200 , remains bonded and fixed at its second end  220   b  to wall portion  301   c  of bottle holder  300 , the sealing element is adapted to stay in the interior space enclosed by bottle holder  300 . 
   As another characteristic configuration of toner bottle  200 , a toner loading portion for loading toner into main part  201  is arranged at rear end part  201   b  of toner bottle  200 . 
   Now, the configuration of rear end part  201   b  of toner bottle  200  will be described in detail with reference to the drawings. 
     FIG. 17  is an illustrative view showing a configuration of the rear end part of the toner bottle and a bottle cap according to the present embodiment;  FIG. 18  is an perspective view showing a configuration of the rear end part of the toner bottle and the bottle cap;  FIG. 19A  is a partial detailed view showing a structure of the engagement portion of the bottle cap with a toner loading portion;  FIG. 19B  is a partial detailed view showing a structure of the engagement portion of the toner loading portion with the bottle cap; and  FIG. 20  is a perspective view showing another configurational example of the engagement portion between the toner bottle and a bottle cap. 
   In toner bottle  200  ( FIG. 7   a ), a toner loading portion  230  having a toner loading opening  230   a  ( FIG. 17 ) for loading toner into main part  201  is projectively formed in main part  201 &#39;s rear end part  201   b  that is located on the side opposite to front end part  201   a . A bottle cap (cap element)  260  (FIG.  17 ) that can seal and open this toner loading opening  230   a  is detachably provided for toner loading portion  230 . This toner loading portion  230  and bottle cap  260  are constructed so as to detachably join to each other by screw joint. 
   As shown in  FIGS. 17 and 18 , toner loading portion  230  is formed projectively to the rear in the longitudinal direction of toner bottle  200  with toner loading opening  230   a  formed at its front end  230   b  and a threaded portion (male thread)  240  formed on its outer periphery  230   c.    
   Further, a cap locking projection (second projection)  250  is projectively formed near the terminal of threaded portion  240  in the vicinity of the proximal part, designated at  230   d , of toner loading portion  230 . 
   On the other hand, bottle cap  260  is constructed so as to enclose toner loading opening  230   a  and outer periphery  230   c  of toner loading portion  230 . Formed on the bottle cap  260 &#39;s inner periphery, designated at  260   c , which opposes the outer periphery  230   c , is a threaded portion (female thread)  270  to mate threaded portion  240  of toner loading portion  230 . Further, a locking projection (first projection)  280  is projectively formed near the screw-starting end of threaded portion  270  in the vicinity of the opening side end, designated at  260   b , of bottle cap  260 . 
   As seen in  FIG. 5 , bottle cap  260  also incorporates an IC chip (electric recording medium)  261  with the number of times of recycling, ID information on the toner being filled and the like recorded therein, so that information on toner bottle  200  can be read by image forming apparatus  1  when the toner bottle is set therein. 
   Here, locking projection  280  of bottle cap  260  and locking projection  250  of toner loading portion  230  will be described in detail with reference to the drawings. 
     FIG. 19A  is a partial detailed view showing the structure of the locking projection of the bottle cap of the toner bottle according to the present embodiment and  FIG. 19B  is a partial detailed view showing the structure of the cap locking projection of the toner loading portion of the toner bottle. 
   As shown in  FIGS. 19A and 19B , locking projection  280  of bottle cap  260  and cap locking projection  250  of toner loading portion  230  have triangular sections approximately similar to each other, so that locking projection  280  and cap locking projection  250  will mesh each other when toner loading opening  230   a  is sealed properly by bottle cap  260  by fastening bottle cap  260  by screw-fitting onto toner loading portion  230 . 
   As shown in  FIG. 19A , locking projection  280  of bottle cap  260  is formed of a first slope  280   a  on the upstream side with respect to the direction in which bottle cap  260  is fastened and a second slope  280   b  on the downstream side. 
   The inclination angle θa of first slope  280   a  is formed to be more acute than the inclination angle θb of second slope  280   b . In other words, first slope  280   a  is formed to be more gentle than second slope  280   b.    
   On the other hand, as shown in  FIG. 19B , cap locking projection  250  is formed of a first slope  250   a  on the upstream side with respect to the direction in which toner loading portion  230  is fastened and a second slope  250   b  on the downstream side. 
   The inclination angle θa of first slope  250   a  is formed to be more acute than the inclination angle θb of second slope  250   b . In other words, first slope  250   a  is formed to be more gentle than second slope  250   b.    
   Provided further in the threaded portion  270 &#39;s screw starting end where locking projection  280  is formed is a recess  290  that is recessed approximately similarly to the shape of cap locking projection  250  and contiguously from locking projection  280 . 
   When toner loading portion  230  and bottle cap  260  are fastened to each other, this recess  290  becomes engaged with cap locking projection  250  and set into a condition of being locked. 
   Here, in the present embodiment, cap locking projection  250  is formed near the terminal end of threaded portion  240  in proximal part  230   d  of toner loading portion  230  and locking projection  280  is formed near the screw starting end of threaded portion  270  of opening-side end  260   b  of bottle cap  260 . However, the positions where the projections are formed are not particularly limited. 
   For example, as a variational example, as shown in  FIG. 20 , a cap locking projection  350  may be formed near the screw starting end of threaded portion  240  of front end  230   b  of toner loading portion  230  while a locking projection  380  is formed near the threaded portion  270 &#39;s terminal end in the bottom, designated at  260   d  of bottle cap  260 . 
   Also, the shapes of the aforementioned projections are not limited to those having triangular sections, but the projections also may have arced sections as long as they can establish a locked condition. 
   Next, bottle holder  300  will be described in detail with reference to the drawings. 
     FIG. 21A  is a front view showing a configuration of a bottle holder that constitutes a toner supply device according to the present embodiment;  FIG. 21B  is a perspective view showing the bottle holder, when it is viewed from the rear side;  FIG. 22A  is a perspective view showing a first casing that constitutes the bottle holder;  FIG. 22B  is a perspective view showing a second casing that constitutes the bottle holder;  FIG. 23  is an illustrative view showing a positional relationship between a toner discharge chamber of the bottle holder and scrapers of the toner bottle; and  FIG. 24  is a schematic sectional view showing a configuration of the front end part of the toner bottle. 
   As shown in  FIGS. 7A and 7B , bottle holder  300  has an approximately cylindrical configuration, and is composed of a first casing  301  and second casing  302 , joined to each other so as to cover front end part  201   a  of main part  201 . At the end of the bottle holder  300  an opening  300   a  is formed so as to expose at least ribs  202  which are disposed at front end face  201   d  of front end part  201   a.    
   Formed on the exterior of first casing  301  are a pair of plate-like first and second fixing structures (guide portions)  303  and  304  arranged parallel to each other, for fixing toner supply device  100  to image forming apparatus  1 . Shutter mechanism  400  for controlling discharge of the toner fed from toner supply device  100  to the outside is arranged between these first and second fixing structures  303  and  304 . 
   Accordingly, in order to make shutter mechanism  400  function correctly, the heights of first and second fixing structures  303  and  304  are adjusted so as to assure a clearance between bottle holder  300  and image forming apparatus  1 . 
   Further, in first fixing structure  303 , a pair of rib pieces  303   a  and  303   b  are arranged a predetermined distance apart from one another, forming a guide portion  303   c  extending in the axial direction of toner bottle  200 . Also in second fixing structure  304 , a pair of rib pieces  304   a  and  304   b  are arranged similarly, forming a guide portion  304   c  along the axial direction. 
   As shown in  FIGS. 21A and 21B , bottle holder  300  has toner discharge port  300   b  formed on the bottom side of first casing  301  between first fixing structure  303  and second fixing structure  304 . This toner discharge port  300   b  is adapted to be opened and closed by shutter mechanism  400 . 
   As shown in  FIG. 22A , in first casing  301 , a first dam portion  301   b  for holding back the toner is formed on the inner peripheral surface, designated at  301   a  near the aforementioned toner discharge port  300   b  and a wall portion  301   c  is extended from this first dam portion  301   b  toward the side opposite to toner discharge port  300   b . This wall portion  301   c  is arranged a predetermined distance apart from one end face or abutment surface  301   d  inside first casing  301 . This distance is specified to be marginally greater than the width of the aforementioned scrapers  203 . 
   Similarly to the first casing  301 , second casing  302  is constructed as shown in  FIG. 22B  so that a second dam portion  302   b  for holding back the toner is formed on the inner peripheral surface, designated at  302   a  and a wall portion  302   c  is extended from this second dam portion  302   b . This wall portion  302   c  is arranged a predetermined distance apart from one end face or abutment surface  302   d  inside second casing  302 . This distance is specified to be marginally greater than the width of the aforementioned scrapers  203 . 
   Joining first casing  301  and second casing  302  constitute the bottle holder  300  as shown in  FIG. 21B . 
   When first casing  301  and second casing  302  are joined, a first space  300   c  is defined by enclosure of first dam portion  301   b  of first casing  301 , second dam portion  302   b  of second casing  302 , wall portions  301   c  and  302   c , as shown in  FIG. 23 . 
   In the present embodiment, this first space  300   c  is referred to as a toner discharge control chamber for limiting discharge of toner, while the space (second space) other than the first space, between first dam portion  301   b  and second dam portion  302   b , is designated at  300   d  and referred to as a toner discharge chamber, which functions to discharge the toner from toner bottle  200  after its temporal storage. 
   Toner discharge control chamber  300   c  is not a space from which toner is actually discharged, but functions as a space for allowing scraper  203  that has come over first dam portion  301   b  to pass therethrough. In this case, though some toner which has ridden over first dam portion  301   b  with scrapers  203  exists in toner discharge control chamber  300   c , this toner will be scraped out from the second dam portion  302   b  side by rotational movement of scrapers  203 . 
   On the other hand, toner discharge chamber  300   d  functions as a space for temporarily storing the toner discharged from bottle-side toner discharge port  201   h  of toner bottle  200 . 
   Here, first dam portion  301   b &#39;s abutment  301   d  with scraper  203  is inclined in the rotational direction of scraper  203  (in the direction of the arrow in the drawing) as shown in  FIG. 23  so that scraper  203  can ride over it properly. That is, abutment surface  301   d  is inclined so that it goes away in the rotational direction of scraper  203  from a normal L from rotational center O of toner bottle  200 . 
   In other words, first dam portion  301   b  is disposed on the upstream side of the scraper  203 &#39;s direction of toner conveyance, and first dam portion  301   b &#39;s abutment surface  301   d  with scraper  203  is arranged as a slope forming a predetermined angle β with normal L from the rotational center O, to thereby define toner discharge chamber  300   d . This angle β is determined as appropriate depending on the scraper  203 &#39;s material, length and other factors. 
   As another feature, first dam portion  301   b  is disposed slightly away from toner discharge port  300   b  in the scraper  203 &#39;s rotational direction. This arrangement enables easy accommodation of toner in toner discharge chamber  300   d . In this way, by making toner easily be stored in toner discharge chamber  300   d , it is possible to keep constant the amount of toner supply to be discharged through toner discharge port  300   b . Thus, it is possible to realize stable toner supply. 
   Similarly to first dam portion  301   b , second dam portion  302   b  is formed so that its abutment surface  302   d  with scraper  203  (the surface on the toner discharge control chamber  300   c  side) is arranged as a slope forming a predetermined angle β with normal L from the rotational center O, to thereby define toner discharge chamber  300   d . This angle β is determined as appropriate, depending on the scraper  203 &#39;s material, length and other factors. 
   In connection to the above, the distance between first dam portion  301   b  and second dam portion  302   b  on the toner discharge chamber  300   d  side should at least have a distance that will not close toner discharge port  300   b . Since it is necessary to accumulate a certain amount of toner in toner discharge chamber  300   d  from a viewpoint of stable toner supply, the distance should be specified as appropriate in accordance with the desired amount of toner being stored. 
   In addition, though the aforementioned scraper  203  was mentioned to have a plate-like configuration it should not be limited to this. For example, the scraper may have an approximately V-shaped cross-section. If scraper  203  has an approximately V-shaped cross-section, it can provide sealing function of sealing between the inner peripheral surface of bottle holder  300  and toner bottle  200 , hence no separate sealing member is needed. 
   In accordance with the toner supply assembly  500  thus constructed, since toner bottle  200  is rotatably supported by bottle holder  300 , there must be a certain amount of clearance between toner bottle  200  and bottle holder  300 . To deal with this, in the present embodiment, two V-rings  501  and  502  for providing a sealing function are attached on front end part  201   a  of main part  201  of toner bottle  200 , as shown in  FIG. 24 . 
   V-ring  501  is fitted on a peripheral surface  201   i  of front end part  201   a  at a position outside the position where scrapers  203  are fixed, while V-ring  502  is fitted at the end surface, designated at  201   g , of front end part  201   a  at a position inside the position where scrapers  203  are fixed. 
   Arranged further outside of the position where V-ring  501  is fitted is a slip ring  503  of a plate-like annular member for creating clearance between toner bottle  200  and bottle holder  300  and allowing toner bottle  200  to rotate smoothly. 
   V-ring  501  is attached to main part  201  with its sealing flange  501   a  pressed against slip ring  503 , while V-ring  502  is attached to main part  201  with its sealing flange  502   a  pressed against the inner peripheral surface (described later) of bottle holder  300 . In this way, these two V-rings  501  and  502  provide sealing function. 
   Slip ring  503  is fitted rotatably on peripheral surface  201   i  of front end part  201   a  of main part  201  and is adapted to be fixed to the inner peripheral surface of bottle holder  300  when toner bottle  200  is attached to bottle holder  300 . 
   With this arrangement, slip ring  503  can be fixed to the bottle holder  300  side, so that main part  201  of toner bottle  200  will rotate along the inner peripheral surface of the slip ring  503 . 
   Now, one example of slip ring  503  will be described with reference to the drawings. 
     FIG. 25  is a plan view showing a configuration of the slip ring of a toner bottle as a part of the toner supply device according to the present embodiment, and  FIG. 26  is a schematic sectional view showing the bottle holder attached to the front end part of the toner bottle. 
   As shown in  FIG. 25 , slip ring  503  is configured so that its inner periphery is formed with a plurality of projections  503   a  that will come into point contact with the fitted surface, i.e., peripheral surface  201   i , in front end part  201   a  of main part  201  and an essentially arced supporting portion  503   c  that has the same curvature as the peripheral surface  201   i  and hence comes into line contact with peripheral surface  201   i  while a projection  503   b  is formed at the top of the outer peripheral surface. This projection  503   b  is fitted into an unillustrated cutout formed on the inner peripheral surface of bottle holder  300 . 
   Since, in general, slip ring  503  and main part  201  of toner bottle  200  are adapted to slide along each other, it is possible to rotate toner bottle  200  smoothly without load if friction therebetween is minimized. 
   Accordingly, provision of multiple projections  503   a  that come into point contact with peripheral surface  201   i  ( FIG. 24 ) on the inner peripheral surface of slip ring  503  as shown in  FIG. 25  reduces the total contact area between toner bottle  200  and slip ring  503 , hence making it possible to reduce friction between slip ring  503  and main part  201  of toner bottle  200 . In this way, it is possible to reduce the rotational load which arises due to increase in friction, and hence rotate toner bottle  200  smoothly inside slip ring  503 . 
   It is noted that the shape of slip ring  503  should not be limited to the configuration shown in  FIG. 25 , but slip ring  503  may have a shape that supports toner bottle  200  at pointed contacts, such as a polygonal shape, for example. 
   In sum, plate-like slip ring  503  has, on its inner periphery, an arc of line-contact projection  503   c , which ranges in a predetermined angle and is margined with a predetermined clearance over peripheral surface  201   i  of toner bottle  200  and the remaining arc having a greater radius with multiple projections  503   a  projected inwards in parts therefrom. 
   With this configuration, the bottle can be supported by arced area at its bottom where the bottle weight acts thereon to prevent abrasion while the other part is supported by essentially pointed contacts, of multiple projections arranged at intervals of a predetermined distance or, of a polygonal shape, whereby it is possible to reduce the sliding load. 
   Further, since sealing flange  501   a  ( FIG. 24 ) of V-ring  501  is adapted to abut this slip ring  503 , it is possible to reliably prevent toner from leaking downward (in the direction of gravity) in bottle holder  300 . 
   Also, V-ring  502  is attached to front end part  201   a  as shown in  FIG. 26  so that its sealing flange  502   a  comes into pressing contact with inner peripheral surface  300   e  of bottle holder  300  when front end part  201   a  of main part  201  of toner bottle  200  is supported by bottle holder  300 . This construction makes it possible to prevent toner leakage from the rear end  300   f  side of bottle holder  300 . 
   It should be noted that the joint between first casing  301  and second casing  302  is properly sealed. 
   As described above, any portion of bottle holder  300  which is likely to cause toner leakage is completely sealed. 
   Further, formed on the peripheral surface of front end part  201   a  of main part  201  of toner bottle  200  are a plurality of plate-like ribs  210  made of elastic resin etc., and arranged obliquely in parallel to each other, as shown in  FIG. 26 , so that these ribs  210  will come into press-contact with inner peripheral surface  300   e  of bottle holder  300  when toner bottle  200  is held by bottle holder  300 . With this arrangement, it is possible to push out the toner that has entered the gap between toner bottle  200  and bottle holder  300  as these ribs  210  rotate. 
   As described, bottle holder  300  is composed of two separate casings, namely first and second casings  301  and  302 , being joined together. When these first and second casings  301  and  302  are detachably joined, it is possible to easily replace the expendable sealing elements (V-rings  501 ,  502 , slip ring  503 , ribs  202 ) by unjoining first and second casings  301  and  302  when maintenance of toner supply device  100  is needed. This means improvement in maintenance of toner supply device  100 . 
   In general, in order to avoid toner leakage and other defects, bottle holder  300  and toner bottle  200  need to be formed with dimensional accuracy, particularly in the supported portion of toner bottle  200  by bottle holder  300 . 
   However, since toner bottle  200  is usually formed by blow molding, the toner bottles are prone to include variations in size when they are molded. Similarly, bottle holder  300  is also formed by blow molding, so that the bottle holders are prone to include variations in size when they are molded. 
   In the above embodiment, since V-ring  502  is made to provide sealing function by pressing its sealing flange  502   a  into contact with inner peripheral surface  300   e  of bottle holder  300  as described above, it is possible to absorb the size variations of bottle holder  300  and toner bottle  200  originating from molding, in the clearance between toner bottle  200  and bottle holder  300 , or more clearly, in the space formed between the surface of main part  201  of toner bottle  200  and bottle holder  300 . 
   Next, shutter mechanism  400  will be described with reference to the drawings. 
     FIG. 27A  is an illustrative view showing the bottle holder with its toner discharge port open,  FIG. 27B  is an illustrative view showing the bottle holder with the toner discharge port closed by a shutter mechanism, and  FIG. 28  is an illustrative view showing the schematic structure of the rear side of the bottle holder. 
   As shown in  FIGS. 27A and 27B , shutter mechanism  400  has a plate-like shutter member  401  that is slidable in the directions of arrows F and R, in the bottom of bottle holder  300 . In the present embodiment, the side on which ribs  202 ,  202  of toner bottle  200  are projected from opening  300   a  at the front end of bottle holder  300  is called the front (F) side and the opposite is called the rear (R) side. 
   In shutter mechanism  400 , as shutter member  401  slides in the direction of arrow. R, toner discharge port  300   b  of bottle holder  300  is opened, as shown in  FIG. 27A . When shutter member  401  slides in the direction of arrow F, toner discharge port  300   b  of bottle holder  300  is closed, as shown in  FIG. 27B . 
   As shown in  FIG. 28 , bottle holder  300  is formed with first and second guide members  306  and  307  for guiding shutter member  401 . 
   First guide member  306  is a flat plate-like member essentially parallel to the bottom surface of bottle holder  300  and is formed with an opening  306   a  that communicates with toner discharge port  300   b  of the bottle holder  300 . Further, the side edge portions  306   b ,  306   b , of first guide member  306 , located at both sides with respect to the directions of arrows F and R, are formed to be thin with the attachment side to bottle holder  300  indented at both sides. These side edge portions  306   b ,  306   b  will function as guide rails for shutter member  401 . 
   On the other hand, second guide member  307  consists of two guide plates  307   a  and  307   b  with their plate surfaces opposing each other, which are extended in the direction of arrow. R on the downstream side, with respect to the direction of arrow R, of the attachment position of first guide member  306 . These guide plates  307   a  and  307   b  will function as guide rails for shutter member  401 . 
   Now, shutter member  401  will be described with reference to the drawings. 
     FIG. 29A  is a perspective view, viewed from the front side, showing the configuration of the shutter mechanism for the toner supply device in accordance with the present embodiment,  FIG. 29B  is a perspective view showing the shutter mechanism when viewed from the rear side,  FIG. 30A  is an illustrative view showing the relationship between the shutter mechanism and the first guide member of the bottle holder, and  FIG. 30B  is an illustrative view showing the relationship between the shutter mechanism and the rotation of the toner bottle. 
   Shutter member  401  is made of plate-like resin, and is composed of a shutter part  401   a  for actually covering the opening and a guide part  401   b  extended from the shutter part  401   a.    
   As shown in  FIG. 29A , shutter part  401   a  is formed with a regulating member  402  for limiting movement in shutter member  401 . This regulating member  402  is composed of an essentially L-shaped main piece  402   a  connected at its one end to shutter part  401   a  and first and second hooks  402   b  and  402   c  formed in the end opposite to the connected side with shutter part  401   a  of main piece  402   a.    
   A gap of a predetermined distance is formed between first and second hooks  402   b  and  402   c . The gap distance is determined such that the front end of second hook  402   c  touches first hook  402   b  when the former falls down towards the latter. 
   On the undersurface of shutter part  401   a , a first slider  403  that slidably holds first guide member  306  ( FIG. 28 ) having toner discharge port  300   b  of the aforementioned bottle holder  300  is formed extending in the longitudinal direction of shutter member  401 , as shown in  FIG. 29B . That is, as shown in  FIG. 30A , first slider  403  slidably holds first guide member  306  by means of a pair of hooks  403   a ,  403   a  arranged at both sides. 
   On the underside of guide part  401   b , a second slider  404  that is slidably supported by guide plates  307   a  and  307   b  of second guide member  307  is formed extending in the longitudinal direction of shutter member  401 , as shown in  FIG. 29B . Second slider  404  has a pair of slide plates  404   a ,  404   a  to be guided by guide plates  307   a ,  307   a  of second guide member  307 . 
   Further, formed on the rear side ( FIG. 29B ) of shutter part  401   a  is a spongy Mylar seal  405  for hermetically sealing toner discharge port  300   b  of bottle holder  300 . The size of Mylar seal  405  is not particularly limited as long as it can hermetically seal the toner discharge port  300   b  when shutter part  401   a  of shutter member  401  covers toner discharge port  300   b.    
   Concerning slide plates  404   a ,  404   a  ( FIG. 29B ) of second slider  404 , when shutter member  401  has moved to the arrow-F side ( FIG. 28 ), or when opening  300   a  of bottle holder  300  is closed, projecting piece  205  ( FIGS. 27A and 27B ) formed on the toner bottle  200  surface fits between slide plates  404   a ,  404   a  as shown in  FIG. 30B  to thereby restrain the toner bottle  200  from rotating. When shutter member  401  is moved in the direction of arrow R, slide plates  404   a ,  404   a  also move in the direction of arrow R to thereby cancel the engagement with projecting piece  205  ( FIG. 27A ). 
   This movement cancels restraint on toner bottle  200 &#39;s rotation. That is, when toner discharge port  300   b  of bottle holder  300  is released so that toner supply device  100  makes a toner supply operation, rotation of toner bottle  200  will not be hindered. 
   Next, toner supply assembly mounting mechanism  600  will be described with reference to the drawings. 
     FIG. 31  is an illustrative view showing the structure of a toner supply assembly mounting mechanism as a part of a toner supply device according to the present embodiment, and  FIG. 32  is an illustrative view showing the structure of a supply passage part for coupling the toner supply assembly mounting mechanism with a developing unit. 
   As shown in  FIGS. 1 ,  2 ,  5  and  6 , toner supply assembly mounting mechanism  600  is constructed such that toner supply assembly  500  is disposed essentially parallel to, and opposing, developing unit  23  with transfer belt unit  30  disposed therebetween. Toner supply assembly mounting mechanism  600  is constructed so that two toner supply assemblies  500   a  for storing black toner can be mounted together. 
   In toner supply assembly mounting mechanisms  600 , mount bases  602  ( 602   a ,  602   b ,  602   c  and  602   d :  FIGS. 5 and 6 ) onto which toner supply assemblies  500  are mounted are formed lengthwise in the direction (the transfer belt width direction) approximately perpendicular to the transfer belt&#39;s direction of conveyance. 
   As shown in  FIG. 5 , toner supply assemblies  500  are fixed to corresponding drive mechanisms  701  ( 701   a ,  701   b ,  701   c  and  701   d ), respectively, on the bottle holder  300  side while toner bottles  200  are fixed by holding belts  702  on the opposite side. 
   Provided for each drive mechanism  701  is an actuator (not shown) which, when toner supply assembly  500  is mounted to mount base  602 , transfers driving force (rotational force) to the bottle by coupling itself with toner bottle  200 &#39;s ribs  202  ( FIG. 7 ) that are projected from opening  300   a  of the aforementioned bottle holder  300 . Usually, the actuator is composed of a motor, and is controlled to drive in accordance with the condition of toner being supplied. 
   On the other hand, holding belt  702  ( FIG. 5 ) is adapted to hold toner bottle  200  of the toner supply assembly  500  when toner supply assembly  500  is mounted to mount base  602 , and is removably attached to mount base  602 . Holding belt  702  is attached to mount base  602  to hold toner bottle  200 , leaving a clearance so that the toner bottle  200  is rotatable or touching the toner bottle  200  with such friction as to allow the bottle to rotate. 
   In toner supply assembly mounting mechanism  600 , the mount base  602  on which toner supply assembly  500  is to be mounted, has a toner feed port  611  ( 611   a ,  611   b ,  611   c  or  611   d ) on the upper surface thereof as shown in  FIG. 6 . This toner feed port is disposed at one end side on the upper surface where bottle holder  300  of toner supply assembly  500  is mounted, correspondingly to shutter mechanism  400  for the bottle holder  300 . On the underside of the mount base, supply passage part  612  ( 612   a ,  612   b ,  612   c  or  612   d ) for toner conveyance is provided to establish communication between the toner supply port  611  and developing unit  23  that is arranged under toner supply assembly mounting mechanism  600 . 
   Here in  FIG. 6 , for description convenience, mount base  602   a  corresponding to toner supply assembly  500   a  of black toner is partially omitted. 
   Supply passage part  612   a  provided in mount base  602   a  for toner supply assembly  500   a  for black toner ( FIG. 1 ) has two toner feed ports  611   a ,  611   a  corresponding to two toner supply assemblies  500   a . That is, this supply passage part is constructed so as to receive toner fed from the two ports and feed the toner to single developing unit  23   a  for black toner through toner input port  234   a  ( FIGS. 2 and 3 ) formed in developing unit  23   a.    
   Each toner supply assembly mounting mechanism  600  is constructed as shown in  FIGS. 3 and 31  such that toner fed from toner supply assembly  500  is delivered from toner feed port  611  that is disposed outside the area of the transfer belt with respect to the direction perpendicular to the transfer belt&#39;s direction of conveyance, or in short, outside the width W of the transfer belt. 
   On the other hand, each of mount bases  602   b  to  602   d  of toner supply assemblies  500   b  to  500   d  for cyan, magenta and yellow toners is formed with a casing  610   a  ( FIG. 31 ) that has a box shape elongated in the width direction of the transfer belt. The casing  610   a  incorporates a first toner agitator shaft (toner conveyor means)  610   b  and a second toner agitator shaft (toner conveyor means)  610   c , arranged parallel to each other along the axis direction of developing roller  231  ( FIG. 2 ). 
   The interior of casing  610   a  is divided into a first toner chamber (toner reservoir)  610   e  with first toner agitator shaft  610   b  disposed therein and a second toner chamber (toner reservoir)  610   f  with second toner agitator shaft  610   c  disposed therein, by a partitioning element  610   d.    
   First and second toner agitator shafts  610   b  and  610   c  have screws  610   b   1  and  610   c   1  for agitating and conveying toner, respectively, and are driven by an unillustrated drive motor by way of drive gears  610   b   2  and  610   c   2  arranged on the other side  610   a   2  of casing  610   a.    
   Toner support plates  610   b   3  and  610   c   3  are provided for first and second toner agitator shafts  610   b  and  610   c , respectively, at their downstream side ends with respect to the direction of toner conveyance so as to receive the toner being conveyed. 
   Here, the toner agitating means should not be limited to screws  610   b   1  and  610   c   1 , but it may be a structure in which a multiple number of agitating vanes tilted with the direction of toner conveyance are formed on the first and second toner agitator shafts  610   b  and  610   c , for example. Also any other configuration can be used as long as it can achieve the same effect. 
   Partitioning element  610   d  is formed in casing  610   a  along the casing length or along the first and second agitator shafts  610   b  and  610   c , having toner chamber communication ports  610   d   1  and  610   d   2  formed near both side walls of casing  610   a  to allow for toner passage between first and second toner chambers  610   e  and  610   f . These toner chamber communication ports  610   d   1  and  610   d   2  permit toner to circulate from first toner chamber  610   e  to second toner chamber  610   f  and from second toner chamber  610   f  to first toner chamber  610   e.    
   On the first end side, designated at  610   a   1 , of casing  610   a , a toner feed port  611  for receiving toner supply from toner bottle  200  arranged on the top thereof is formed while a toner feed port  610   a   4  for delivering the toner from casing  610   a  to supply passage part  612  that feeds toner to developing unit  23  arranged below is formed. 
   The opening of toner feed port  611  is formed at a position opposing part of first toner agitator shaft  610   b  for agitating and conveying toner from first end side  610   a   1  to second end side  610   a   2  of casing  610   a.    
   On the other hand, the opening of toner feed port  610   a   4  is formed at a position opposing part of second toner agitator shaft  610   c  for agitating and circulatively conveying toner from second end side  610   a   2  to first end side  610   a   1  of casing  610   a.    
   Each supply passage part  612  is formed so that its top is integrated with toner supply assembly mounting mechanism  600 , and a developing unit attachment portion  612   a  for detachable attachment to developing unit  23  is provided at the bottom thereof, as shown in  FIG. 32 . 
   An opening of a toner input port  612   b   1  for toner input is formed at the top of supply passage part  612 , and a toner passage  612   c   1  for toner to pass from this toner input port  612   b   1  to developing unit attachment portion  612   a  is provided approximately linearly from top to bottom. 
   Further, as shown in  FIG. 6 , at one end side on the top of casing  610   a  of mount base  602 , bottle holder guide portions  620 ,  620  that engage portions  303   c  and  304   c  (FIG.  7 B) of first and second fixing structures  303  and  304  and guide them are projectively formed at the positions opposing first and second fixing structures  303  and  304  ( FIG. 7B ) of bottle holder  300  when toner supply assembly  500  has been mounted. Bottle holder guide portions  620 ,  620  are arranged essentially parallel to each other with toner feed port  611  positioned therebetween and extended in the longitudinal direction of mount base  602 . 
   Toner feed port  611  of mount base  602  is formed at the position corresponding to shutter member  401  ( FIG. 27A ) of shutter mechanism  400  provided for bottle holder  300  when toner supply assembly  500  is mounted. In other words, toner feed port  611  is formed at a position so as to be able to receive toner discharged from toner discharge port  300   b  when the toner discharge port  300   b  of bottle holder  300  is released by shutter mechanism  400 . 
   Formed in the vicinity of toner feed port  611  is a projection piece  613  ( 613   a ,  613   b ,  613   c  or  613   d :  FIG. 6 ), which is hooked by a hooking portion (described later) of regulating member  402  ( FIGS. 27A and 29A ) provided for shutter member  401  of shutter mechanism  400  to limit the movement of shutter member  401 . 
   On the side longitudinally opposite to toner feed port  611  of mount base  602 , a supporter  614  ( 614   a ,  614   b ,  614   c  or  164   d ) for supporting the rear end (the end on the side opposite to the mounted portion of bottle holder  300 ) of toner bottle  200  when toner supply device  100  is mounted is formed. 
   This supporter  614  is to create a predetermined clearance between toner bottle  200  and mount base  602  and functions to smoothen the rotation of toner bottle  200 . Here, the configuration and the like of supporter  614  is not particularly limited; any configuration and material can be used as long as toner bottle  200  can rotate smoothly. 
   The forming position of projection piece  613  provided near toner feed port  611  is determined by the regulatory operation of regulating member  402 . 
   Next, how the forming position of projection piece  613  is determined will be described with reference to the drawings. 
     FIG. 33A  is an illustrative view showing the positional relationship between the regulating member and the projection piece before the toner supply device according to the present embodiment is mounted to the mount base;  FIG. 33B  is an illustrative view showing the positional relationship between the regulating member and the projection piece when the toner supply device has been mounted to the mount base; and  FIG. 33C  is an illustrative view showing the positional relationship between the regulating member and the projection piece when the toner supply device is dismounted from the mount base. 
   Projection piece  613  is formed at such a position that shutter member  401  will open toner discharge port  300   b  of bottle holder  300  by its engagement with regulating member  402  when toner supply device  100  has been completely attached to mount base  602  and will close toner discharge port  300   b  of bottle holder  300  when toner supply device  100  is removed from mount base  602 . 
   Regulating member  402  has first hook  402   b  and second hook  402   c  formed at the front end (on the side of engagement with projection piece  613 ) of main piece  402   a , as already mentioned. 
   First hook  402   b  is disposed at a position more front than second hook  402   c  and its abutment surface  402   d  against projection piece  613  is formed beveled so that it can easily ride over the projection piece  613 . Here, abutment surface  402   d  is so inclined that its contact area with the top of projection piece  613  is minimized. 
   When abutment surface  402   d  of first hook  402   b  is inclined in this way, regulating member  402  is moved in the direction of arrow F from the state shown in  FIG. 33A , and first hook  402   b  rides over projection  613  formed on first casing  301 . With a further movement of the regulating member in the direction of arrow F, second hook  402   c  also rides over projection  613 . From this state, when regulating member  402  is caused to move in the direction opposite to the direction of arrow F, movement of regulating member  402  is obstructed by projection piece  613  and second hook  402   c  (the state shown in  FIG. 33B ). 
   Next, how toner supply device  100  is mounted to the image forming apparatus will be described. 
   Toner supply device  100  is adapted to be mounted to toner supply assembly mounting mechanism  600  by sliding bottle holder  300  side of toner supply assembly  500  over and along mount base  602  of toner supply assembly mounting mechanism  600 . 
   By this sliding movement of toner supply assembly  500 , shutter member  401  of shutter mechanism  400 , provided for bottle holder  300 , opens or closes toner discharge port  300   b  of the bottle holder  300 , as shown in  FIGS. 33A ,  33 B and  33 C. 
   Movement of shutter member  401  is controlled by regulating member  402  that is integrally formed with shutter member  401 . 
   In the case where toner discharge port  300   b  of bottle holder  300  is opened by shutter mechanism  400 , as shutter member  401  moves in the direction of arrow R, regulating member  402  moves and takes the state shown in  FIG. 33B . Then, with a further movement in the direction of arrow R, second hook  402   c  abuts projection piece  613  and falls down to the first hook  402   b  side, as shown in  FIG. 33C , so that the first hook  402   b  together with second hook  402   c  ride over projection piece  613  as the movement in the direction of arrow. R continues. In this way, toner discharge port  300   b  of bottle holder  300  is released. 
   In the case where toner supply assembly  500  is dismounted from toner supply assembly mounting mechanism  600 , as toner supply assembly  500  is pulled out from toner supply assembly mounting mechanism  600 , the aforementioned actions take place in the reverse order, that is, shutter member  401  moves in the direction of arrow F ( FIG. 33A ) so that toner discharge port  300   b  of bottle holder  300  is closed. 
   Next, the operation of bottle cap  260  ( FIGS. 17 to 20 ) of toner bottle  200  according to the present embodiment will be described. 
   When the toner in toner bottle  200  set in image forming apparatus  1  has been used up, it is necessary to replace the toner bottle  200  with a new one. The toner bottle  200  with its toner used up is adapted to be able to be recycled by loading toner into it. 
   Specifically, according to toner bottle  200  of the present embodiment, it is possible to simply reuse the toner bottle by removing bottle cap  260  from toner loading portion  230  and loading toner into the bottle from toner loading portion  230 . 
   When toner bottle  200  is full of toner and ready for use, bottle cap  260  fastened by screw-fitting on toner loading portion  230  is in locked by the engagement between locking projection  280  of bottle cap  260  and cap locking projection  250  of toner loading portion  230 . 
   As shown in  FIGS. 19A and 19B , the locked state of bottle cap  260  is established by abutment between second slope  280   b  of locking projection  280  and second slope  250   b  of cap locking projection  250  in toner loading portion  230  and abutment between a first slope  270   a  of threaded portion  270  and first slope  250   a  of cap locking projection  250 . 
   To remove bottle cap  260  from toner loading portion  230  by releasing this locked state of bottle cap  260 , bottle cap  260  is turned in the loosening direction (in the direction indicated by arrow  260 S 2  in the drawing). Then, bottle cap  260 , as being slightly deformed, causes locking projection  280  to move up along second slope  250   b  of cap locking projection  250  to the top and ride over cap locking projection  250 , thus releasing the locked state. 
   Then, bottle cap  260  is removed from main part  201  and toner is loaded from toner loading opening  230   a . After the bottle has been filled with toner, bottle cap  260  is screw-fitted and fastened again to main part  201  to complete the toner loading operation. 
   When bottle cap  260  is fastened by screw-fitting to toner loading portion  230 , bottle cap  260  is turned in a fastening direction (in the direction of arrow  260 S 1  in the drawing) until locking projection  280  abuts cap locking projection  250 . 
   Then, the bottle cap is further turned so that locking projection  280  moves up along first slope  250   a  of cap locking projection  250  to the top and rides over cap locking projection  250  to thereby establish the locked state. 
   In this condition, toner loading opening  230   a  is hermetically closed by bottle cap  260 . 
   According to the present embodiment, the inclination angle θa of first slope  250   a  of cap locking projection  250  is formed to be more acute than the inclination angle θb of second slope  250   b , that is, the first slope is formed to be more gentle than second slope  250   b . Hence, bottle cap  260  can be operated with a weaker force when it is set into the locked state than when it is released from the locked state, and bottle cap  260  is hard to loose even if it is wrongly operated, it is possible to handle the toner bottle  200  in safety. 
   Next, loading of toner into toner bottle  200  according to the present embodiment will be described with reference to the drawings. 
     FIG. 34  is an illustrative view showing a schematic configuration of a device for loading toner into the toner bottle according to the present embodiment. 
   When toner bottle  200  is loaded (refilled) with toner, toner bottle  200  is set on a toner feeder base  710  approximately upright with toner loading portion  230  up, and a toner feeder  720  from an unillustrated toner loading machine is set to toner loading portion  230 . 
   Toner feeder  720  includes a toner loading nozzle  721  for loading toner into main part  201  of toner bottle  200  and a suctioning portion  722  for suctioning air around proximal part  230   d  of toner loading portion  230 . 
   Toner loading nozzle  721  is adapted to load toner as being positioned so as to oppose toner loading opening  230   a  from above or so as to be inserted into main part  201  from toner loading opening  230   a.    
   Suctioning portion  722  is arranged to enclose outer periphery  230   c  of toner loading portion  230  and suction air around proximal part  230   d  of toner loading portion  230  along the outer periphery thereof. 
   Loading of toner into toner bottle  200  by toner feeder  720  is performed by feeding toner into main part  201  from toner loading nozzle  721  while suctioning and cleaning spilt or scattered toner in the atmosphere around toner loading port  230  by suctioning portion  722 . 
   Since, in the above way, the step of toner loading and the step of air suctioning around toner loading portion  230  are executed in parallel, it is possible to perform a toner loading operation in a short period and hence it is possible to not only improve work efficiency but also present a beneficial apparatus and work environments without contaminating the operator and apparatus atmosphere with flooded toner from toner loading opening  230   a.    
   According to the present embodiment thus constructed, use of toner bottle  200  makes it possible to refill the bottle with toner by simply removing bottle cap  260  after toner is used up, and it is possible to attach the bottle cap  260  in a reliable manner. This enables easy recycling of toner bottle  200 . 
   Also, according to the present embodiment as shown in  FIGS. 5 and 7A , the embedment of IC chip  261  into bottle cap  260  of toner bottle  200  facilitates confirmation of the information on recycling of toner bottle  200 . 
   Though, in the present embodiment, IC chip  261  is embedded in bottle cap  260 , the present technology should not be limited to this. For example, an IC chip may be fitted to main part  201 . 
   Further, in the present embodiment, locking projection  280  is formed on the extension of threaded portion  270  of bottle cap  260  and cap locking projection  250  is formed at a position, on toner loading projection  230 , corresponding to the threaded portion  270 . However, the present technology is not limited by the arrangement of locking projections. For example, locking projections may be formed respectively at positions on the peripheral edges of bottle cap  260  and proximal portion  230   d  of toner loading portion  230  when toner loading opening  230   a  is hermetically closed by bottle cap  260 . The shapes of the locking projections are also not limited to those of cap locking projection  250  and locking projection  280  of the present embodiment. 
   Moreover, though the present embodiment has been described taking an example in which toner supply device  100  using toner bottle  200  is applied to the image forming apparatus  1  shown in  FIG. 1 , the present technology should not be limited to the above and can be applied to any kinds of image forming apparatuses as long as they use an exchangeable toner container. For example, the technology may be applied to a copier  101  shown in  FIG. 35 . 
   As shown in  FIG. 35 , copier  101  includes an image reader (scanner)  110  disposed above an image forming portion  108  using toner bottle  200  and having almost the same configuration as that of image forming apparatus  1  according to the embodiment described above, and first, second, third and fourth paper feed cassettes  142   a ,  142   b ,  142   c  and  142   d  disposed under image forming portion  108  for supporting multiple kinds of paper, to thereby facilitate a variety of and a large amount of automatic printing. In the drawing, a reference numeral  120  designates a waste toner box for collecting waste toner. 
   Here, in copier  101 , the same components as those in image forming apparatus  1  of the aforementioned embodiment will be allotted with the same reference numerals and description is omitted. 
   Further, the present technology can be developed into any form of other kinds of image forming apparatuses etc., not limited to the image forming apparatus and copier having the above configurations, as long as it is an image forming apparatus having a structure that permits refill of a supply material with an exchangeable supply container. 
   As has been described above, the present technology should not be limited to the above embodiment and example and various changes can be made within the range specified in the scope of claims. That is, any embodied mode obtained by combination of technical means modified as appropriate without departing from the spirit and scope of the present technology should be included in the scope of the technology, as set forth in the following claims.