Patent Publication Number: US-7917055-B2

Title: Toner container including a toner draining unit and a shutter, and corresponding image forming apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a division of and is based upon and claims the benefit of priority under 35 U.S.C. §120 for U.S. Ser. No. 12/354,326 filed Jan. 15, 2009 now U.S. Pat. No. 7,603,054, which is a division of U.S. Ser. No. 11/980,412 filed on Oct. 31, 2007 now U.S. Pat. No. 7,536,139, which is a continuation of U.S. Ser. No. 11/565,814 filed on Dec. 1, 2006 now U.S. Pat. No. 7,406,278, which is a continuation of U.S. Ser. No. 10/514,832 filed on Nov. 18, 2004 now U.S. Pat. No. 7,277,664, which is the National Stage of International Application no. PCT/JP03/11707 filed on Sep. 12, 2003, the entire contents of each of which are incorporated herein. The present invention additionally claims priority to Japanese Patent Application nos. 2003-028700 and 2003-028718 filed on Feb. 5, 2003, and Japanese Patent Application nos. 2002-275691 and 2002-276022 filed Sep. 20, 2002. 
    
    
     TECHNICAL FIELD 
     The present invention relates to an image forming apparatus, a powder supplying unit, a toner container, a powder container, and a reproduction a method of recycling the powder container, and more particularly, to an apparatus that stores a powder such as toner used for the image forming apparatus and reliably supplies the powder to the apparatus body, a container, and a method of recycling the powder container. 
     BACKGROUND ART 
     In a conventional forming apparatus, for example, with a two-component developing unit in which the developing unit that visualizes an electrostatic latent image formed on, for example, an image carrier, uses a toner including a toner and a carrier, since the toner is consumed with the formation of an image, it is necessary to sequentially supply the toner by the consumed amount. Therefore, in the image forming apparatus, a toner container storing the toner is provided, to supply the toner by the consumed amount from the container to the developing unit. 
     As the supply method of the toner from the toner container such as a toner bottle or a toner cartridge to the developing unit, a mechanical auger unit is heretofore mainly used. The toner transfer by the auger unit can control the transfer amount of the toner, but the transfer route is substantially limited to a linear route, and when the transfer route is long, coagulation of the toner may occur, thereby deteriorating the toner quality. Therefore, in the apparatus in which the toner transfer is carried out by the auger unit, the toner container should be arranged near the developing unit. Further, with the auger unit, even if the transfer distance is short, the toner cannot be raised at an acute angle. Therefore, the toner container must be arranged above the developing unit. 
     Patent Literatures 1 and 2 disclose a toner supplying apparatus that can considerably alleviate the problem in the conventional image forming apparatus. The toner supplying apparatus described in the Patent Literatures uses the suction force of a powder pump for the transfer of the toner. Therefore, there are advantages in that there is high flexibility in the arrangement of the toner container and toner can be supplied stably, thereby drawing much attention. 
     The toner container described in the Patent Literatures can be set in a setting unit in the image forming apparatus body with one action of dropping the container downward, at which time, the toner draining unit is automatically opened by a nozzle inserted in the container. When the toner container is taken out, the toner draining unit is automatically closed. This action is performed by a self-closing valve, and the self-closing valve includes a sponge in which a cross-shaped slit is formed at the center thereof. When the nozzle is inserted into the slit, the slit deforms so as to receive it, and when the nozzle is pulled out, the slit is closed due to the righting moment of the sponge to prevent the toner from spilling out of the container. 
     However, in the self-closing valve, the righting moment of the sponge may decrease due to curing at a low temperature, or due to a creep deformation with the lapse of time. When the righting moment decreases, the toner may leak and scatter until the slit of the self-closing valve closes, at the time of taking out the toner container. 
     A toner container resolving this problem is already proposed by the present applicant, and the details are shown in  FIG. 21 . 
     In a toner container  520  shown in  FIG. 21 , an inner shutter  560  is provided as a stopper, instead of the self-closing valve, and the inner shutter  560  includes a shutter member  561 , a spring  562 , a ring sealing member  563 , and a spring bearing  564 , and is provided in a cap member  523 . The shutter member  561  is biased downward by a compression spring  562 , to seal a toner draining port  524  in a state fitted to the ring sealing member  563 , so that the toner does not leak outside. 
     As shown in  FIG. 22 , when the toner container  520  is set from above, a nozzle  551  is inserted while pushing the shutter member  561  upward, thereby releasing a toner drain passage. 
     When the toner container  520  is taken out after use, since the shutter member  561  returns to the original position in the state abutting against the nozzle  551 , due to a biasing force of the spring  562 , the toner leakage can be reliably prevented. 
     As images are formed repetitively by the image forming apparatus, the developer is consumed. Therefore, it is necessary to supply the developer by the consumed amount. For example, when the developing unit that visualizes the electrostatic latent image formed on a latent image carrier uses a two-component developer including the toner and the carrier, it is necessary to sequentially supply the toner by the consumed amount, since the toner is consumed with the image formation. Therefore, in the conventional image forming apparatus, a toner container storing the toner is provided, so as to supply the toner by the consumed amount from the toner container to the developing unit. 
     In the configuration in which the toner is supplied from the toner container, it is necessary to replace the empty toner container every time the toner in the toner container has been consumed. The replacement operation of the toner container is heretofore performed by a user in general. 
     In Patent Literature 3, a toner supplying apparatus is disclosed, in which in order to facilitate the replacement operation of the toner container by users, the toner container is set by dropping the toner container from above at the time of installation, and the toner container is lifted upward and detached at the time of detachment. In this apparatus, a self-closing valve is provided, which automatically opens only by dropping the toner container from above, and automatically closes only by lifting the toner container, in a toner draining unit, being a toner passage in the toner container. Further, the configuration thereof is simple such that a nozzle is provided in a setting unit of the image forming apparatus, and the self-closing valve provided in the toner container opens or closes by inserting or removing the nozzle. 
       FIG. 23  depicts a toner container  20  having a self-closing valve  201  disclosed in the Patent Literature 3. As the self-closing valve  201  of the toner container, one having a cross-shaped slit  201   a  for inserting or removing a nozzle made of a compressed foam sponge seal formed of a non-permeable material is used. The self-closing valve  201  formed of the sponge seal deforms so that when the point of the nozzle is pressed against the center of the cross-shaped slit  201   a , the nozzle can be inserted, and when the nozzle is pulled out, the slit closes due to the righting moment of the sponge to prevent toner scattering caused by the toner spill. 
     Thus, by providing the self-closing valve in the toner draining unit in the toner container, the replacement operation of the toner container by the user is facilitated, and toner scattering at the time of replacement operation can be prevented to some extent. 
     (Patent Literature 1) Japanese Patent Application Laid-Open No. 2001-324863 
     (Patent Literature 2) Japanese Patent Application Laid-Open No. 2002-72649 
     (Patent Literature 3) Japanese Patent Application Laid-Open No. 2001-315851 
     However, the toner container  520  provided with the inner shutter  560  becomes an obstruction to toner discharge, since the inner shutter  560  is located above the nozzle  551  in the set state, and hence a toner bridge phenomenon in the container is likely to occur. The toner bridge in the upper part of the inner shutter  560  is hardly eliminated even by the air supplied for eliminating the toner bridge. As a result, the supply amount of the toner becomes unstable, and hence the residual amount of toner in the toner container may increase extremely. 
     In the self-closing valve in the Patent Literature 3, the righting moment of the sponge may decrease due to curing at a low temperature, or due to a creep deformation with the lapse of time, and when the righting moment decreases, a slight gap may be generated in the slit in the self-closing valve, at the time of taking out the toner container. When a gap is generated, in the conventional configuration in which the toner draining unit is facing the direction of gravity of the toner container, the toner may leak from the gap, drop and scatter. 
     When the nozzle is inserted into or pulled out from the toner container, even when the righting moment does not decrease in the material of the self-closing valve, a certain gap is generated between the self-closing valve and the nozzle. There is the possibility that the toner in the toner container leaks and scatters from this gap. 
     Recently, recycling of the parts constituting the container is considered for resource protection, instead of disposing the used toner container. However, with the conventional toner container, the sealing material formed of the elastic material is bonded to the body portion of the toner draining member (cap member) with an adhesive. Therefore, at the time of recycling the parts of the toner container, a complicated work for detaching the sealing material formed of the elastic material, bonded to the body portion of the toner draining member (cap member) becomes necessary, causing a problem in that recycling of the toner container is not easy. 
     This problem occurs likewise when a powder container for storing powder other than the toner is used. 
     With a view to the above problems, it is an object of the present invention to reduce toner leakage, which is likely to occur at the time of removing the toner container, without using the shutter means coming into the toner container. 
     It is another object of the present invention to reduce leakage of powder from a powder container at the time of setting or detaching the powder container. 
     It is still another object of the present invention to eliminate the shutter means coming into the toner container, to prevent a large amount of residual toner. 
     It is still another object of the present invention to provide a powder container, which makes recycling easy, a reproduction method thereof, a powder supplying unit, in which the powder container can be installed, and an image forming apparatus. 
     DISCLOSURE OF THE INVENTION 
     An image forming apparatus according to one aspect of the present invention includes a toner container that stores toner and supplies the toner to an image forming unit; and a setting unit that sets the toner container to a main body of the image forming apparatus, the setting unit having a nozzle coupled to a part of a toner supply path and the toner container. A fitting direction of the toner container to the setting unit and a coupling direction of the nozzle to the toner container are different. 
     According to the present invention, a nozzle constituting a part of a toner supply path and coupled to a toner container is provided in a setting unit, and the fitting direction of the toner container to the setting unit and the coupling direction of the nozzle to the toner container are different. Therefore, an image forming apparatus in which the residual toner in the toner container is little can be provided. 
     According to present invention, the setting unit includes an opening-closing folder fitted to the main body switchably between a closing position at which the toner container is in a set state and an opening position at which the toner container is in a detachable state, and the toner container is supported by the opening-closing folder. 
     According to the present invention, the setting unit is provided with the opening-closing folder fitted to the apparatus body movably between the closing position at which the toner container is in the set state, and the opening position at which the toner container can be detached, and the toner container is supported by the opening-closing folder. As a result, the opening and closing operation of the opening-closing folder can be used for setting or detaching the nozzle. 
     According to the present invention, the toner container is dropped from above and supported by the opening-closing folder in the setting unit. 
     According to the present invention, since the toner container is dropped from above and supported by the opening-closing folder in the setting unit, setting of the toner container can be facilitated. 
     The image forming apparatus according to the present invention further includes a guide member that guides the toner container dropped into the opening-closing folder to an installation position. 
     According to the present invention, since the guide member that guides the toner container dropped into the opening-closing folder to the installation position is provided, the dropped toner container is guided to the proper setting position, thereby reducing a setting error. 
     According to the present invention, the nozzle is coupled to the toner container by a shift of the opening-closing folder from the opening position to the closing position. 
     According to the present invention, since the nozzle is coupled to the toner container by the shift of the opening-closing folder from the opening position to the closing position, special operation for coupling the nozzle to the toner container is not necessary. 
     According to the present invention, the opening-closing folder is mounted on the main body rotatably between the closing position and the opening position. 
     According to the present invention, since the opening-closing folder is fitted to the apparatus body rotatably between the closing position and the opening position, detachment of the nozzle can be performed by using the rotation operation thereof. 
     According to the present invention, the opening-closing folder is mounted on the body slidably between the closing position and the opening position. 
     According to the present invention, since the opening-closing folder is fitted to the apparatus body slidably between the closing position and the opening position, detachment of the nozzle can be performed by using the sliding operation thereof. 
     The image forming apparatus according to the present invention further includes a locking unit that locks the opening-closing folder at the closing position. 
     According to the present invention, since the locking unit that locks the opening-closing folder at the closing position is provided, the opening-closing folder can be reliably held at the closing position. 
     According to the present invention, the toner container includes a storage member that stores the toner; a cap member provided below the storage member, in which a toner draining unit is formed; and a shutter member that closes the toner draining unit. The nozzle is inserted into a position of the shutter member and connected to the toner draining unit by the shift of the opening-closing folder from the opening position to the closing position. 
     According to the present invention, the toner container includes: a storage member that stores toner; a cap member provided below the storage member and having a toner draining unit formed therein; and a shutter member that closes the toner draining unit, wherein the nozzle is inserted into the position of the shutter member and connected to the toner draining unit, by the shift of the opening-closing folder from the opening position to the closing position. As a result, the shutter member is shifted by the insertion of the nozzle, so that the toner can be supplied. 
     According to the present invention, the opening-closing folder includes a returning unit that returns the shutter member shifted by insertion of the nozzle to a position to close the toner draining unit. 
     According to the present invention, the opening-closing folder is provided with the returning unit that returns the shutter member shifted by the insertion of the nozzle to the original position for closing the toner draining unit. Therefore, when the nozzle is pulled out from the cap member, the shutter member closes the toner draining unit, to prevent toner leakage at the time of pulling out the nozzle. 
     According to the present invention, the returning unit includes a slider that is slidable in a direction of shifting the shutter member; and an elasticity applying member that applies an elastic force to the slider in a direction of returning the shutter member. 
     According to the present invention, the returning unit includes a slider slidable in the shift direction of the shutter member, and an elasticity applying member that applies an elastic force to the slider in a direction of returning the shutter member. As a result, the shutter member can be returned to the original position by the elasticity applying member. 
     According to the present invention, the nozzle is slidably supported by the opening-closing folder. 
     According to the present invention, since the nozzle is slidably supported by the opening-closing folder, it can be prevented that the nozzle abuts against the cap member and is not connected. 
     According to the present invention, the nozzle is formed integrally with the slider. 
     According to the present invention, since the nozzle is formed integrally with the slider, such a problem that only the nozzle is pulled out and the shutter member does not return to the original position can be reliably prevented. 
     A powder container according to another aspect of the present invention includes a bag-like powder storage having an opening at one end; a draining port for draining the powder stored in the powder storage to outside; and a powder draining member mounted on the opening of the powder storage. At least a part of a powder passage from the powder storage to the draining port in the powder draining member is bent. 
     According to the present invention, since the toner passage from a bag-like container as the powder storage to the draining port is bent at one spot or more, when the bag-like container is located above the draining port, the toner in the bag-like container does not move linearly toward the draining port due to gravity. 
     According to the present invention, the powder draining member includes a powder passage near the opening of the powder storage, and a direction of powder passing in a portion of the drain passage near the draining port is inclined with respect to a direction of powder passing in the powder passage. 
     According to the present invention, the powder passing direction in the portion near the draining port is inclined with respect to the passing direction of the powder such as toner, in an inner hole as the powder passage of an external part (upper part) as a base member. Therefore, when the storage container is detached with the bag-like container located above the draining port member, the internal surface near the draining port inclines with respect to the perpendicular direction. As a result, the toner moving in the direction of gravity near the draining port can be received by the internal surface near the draining port, thereby further suppressing toner leakage from the draining port, when the storage container of toner or the like is detached. 
     According to the present invention, the powder storage is formed with a flexible material. 
     According to the present invention, since the powder storage is formed of a flexible material, after the powder storage has been used, the bag-like container can be deformed so as to decrease the volume of the powder storage (bag-like container), thereby enabling a reduction in size of the used powder container such as toner. 
     A powder supplying unit according to still another aspect of the present invention includes a container mounting portion on which a powder container is mounted; and a powder supplying unit that supplies powder in the powder container to an apparatus to which the powder is to be supplied. The powder container mounted on the container mounting portion includes a bag-like powder storage having an opening at one end; a draining port for draining the powder stored in the powder storage to outside; and a powder draining member mounted on the opening of the powder storage. At least a part of a powder passage from the powder storage to the draining port in the powder draining member is bent. 
     According to the present invention, since the powder passage from the bag-like container to the draining port is bent at one spot or more, when the bag-like container is located above the powder draining member, the powder such as toner in the bag-like container does not move linearly toward the draining port due to gravity. Further, when the bag-like container is located above the powder draining member, since at least a part of the portion from the bent portion of the powder passage to the draining port inclines with respect to the perpendicular direction, the powder moving in the direction of gravity can be received by the internal wall of the inclined portion. Therefore, when the bag-like container is located above the powder draining member, leakage of the powder such as toner from the draining port can be suppressed, when the powder container is detached. 
     According to the present invention, the powder supplying unit includes a powder-path forming member that forms a powder path from the powder container to the apparatus to which the powder is to be supplied; and a nozzle detaching unit that attaches or detaches a nozzle for taking in the powder in the powder-path forming member to or from a portion where the draining port of the powder container is formed. 
     According to the present invention, the nozzle is set to or detached from the portion where the draining port of the powder container is formed. As a result, the powder container can be easily detached. 
     According to the present invention, a drain passage that leads the powder from the powder storage to the draining port is formed in the powder container, and the powder container includes a shutter member that is movable between a position for opening an inlet of the drain passage on the powder storage side and a position for closing the inlet. 
     According to the present invention, the shutter member provided in the middle part (inner part) as the draining port member moves between the position where the inlet on the bag-like container side of a shutter hole (draining port) as the drain passage is opened and the position where the inlet is closed, thereby enabling opening or closing of the shutter hole. Therefore, toner leakage due to a decrease in the righting moment of the elastic body, which has occurred when the conventional sealing material formed of an elastic body is used, can be prevented. 
     According to the present invention, the drain passage is formed of a through hole opened to the outside of the powder container. 
     According to the present invention, since the shutter hole (draining port) as the drain passage is a through hole opened to the outside of the powder container, the shutter member is shifted by the insertion of the nozzle for draining the powder, thereby enabling automatic opening of the drain passage. 
     According to the present invention, the nozzle detaching unit shifts the shutter member to the position for closing the inlet of the drain passage in conjunction with a detachment operation of the nozzle, and shifts the shutter member to the position for opening the inlet of the drain passage in conjunction with the detachment operation of the nozzle. 
     According to the present invention, by shifting the shutter member to the position for closing the shutter hole, synchronized with detachment operation of the nozzle from the shutter hole (draining port), the shutter hole can be closed by the shutter member, even when the nozzle is detached from the shutter hole at the time of setting or detaching the powder container, thereby preventing leakage of powder such as toner and toner scattering more effectively. 
     According to the present invention, the shift of the shutter member to the position for closing the inlet of the drain passage is performed by a biasing force of the elastic member. 
     According to the present invention, the shutter member can be shifted to the closing position of the powder draining port by a resilient biasing force of, for example, a compression spring. As a result, there is no need to provide a drive for shifting the shutter member. 
     According to the present invention, the container mounting portion includes a powder container supporting member that movably supports the powder container between a set position where the nozzle is set to the draining port of the powder container and a detached position where the nozzle is detached from the draining port. 
     According to the present invention, since the opening-closing folder is provided as the powder container supporting member that movably supports the powder container between the set position where the nozzle is set to the shutter hole (draining port) of the powder container, and the detached position where the nozzle is detached from the draining port, the opening-closing folder can be used for shifting the powder container between the set position and the detached position. 
     According to the present invention, the powder container is dropped from above and supported by the powder container supporting member in the container mounting portion. 
     According to the present invention, by dropping the powder container from above, with the cap member side facing downward, the powder container can be supported at the predetermined position of the opening-closing folder (the powder container supporting member). As a result, setting of the powder container to the opening-closing folder can be performed by an easy operation of dropping the powder container. 
     The powder supplying unit according to the present invention further includes a guide unit that guides the powder container dropped into the powder container supporting member to a position where the nozzle is set to the draining port of the powder container. 
     According to the present invention, since a guide frame that guides the inserted powder container to the set position is provided in the opening-closing folder (the powder container supporting member), the dropped toner container can be guided to a position where the nozzle can be fitted to the draining port thereof by the guide frame, thereby reducing the possibility of an installation error of the powder container. 
     An image forming apparatus according to still another aspect of the present invention includes a developing unit that develops a latent image on an image carrier by using a powder developer; and a developer supplying unit that supplies the developer to the developing unit. As for the developer supplying unit, a powder supplying unit is used, which includes a container mounting portion on which a powder container is mounted; and a powder supplying unit that supplies powder in the powder container to an apparatus to which the powder is to be supplied. The powder container mounted on the container mounting portion includes a bag-like powder storage having an opening at one end; a draining port for draining the powder stored in the powder storage to outside; and a powder draining member mounted on the opening of the powder storage. At least a part of a powder passage from the powder storage to the draining port in the powder draining member is bent. 
     According to the present invention, by installing the powder supplying unit in the developing unit in the image forming apparatus, leakage of the powder from the powder container can be suppressed. 
     A toner container according to still another aspect of the present invention includes a storage member that stores a toner; and a cap member integrally formed with or fixed to the storage member, and having an opening for draining the toner. The opening for draining the toner includes an inner hole on the storage member side; and a shutter hole through which a shutter member can be inserted or taken out, with the inner hole and the shutter hole being communicated with each other with an angle. The opening for draining the toner is opened or closed by inserting or taking out the shutter member. 
     According to the present invention, the opening for draining the toner has the inner hole on the storage member side, and the shutter hole through which the shutter member can be inserted or taken out, with the inner hole and the shutter hole being communicated with each other with an angle, and the opening for draining the toner is opened or closed by inserting or taking out the shutter member. As a result, the shutter member does not go into the container, thereby preventing a large amount of residual toner. 
     According to the present invention, the cap member is provided in the lower part of the storage member, the inner hole is a longitudinal hole extending vertically, in the state with the cap member facing downward, and the shutter hole is a lateral hole with the axis thereof crossing the axis of the inner hole substantially at right angles. 
     According to the present invention, the cap member is provided in the lower part of the storage member, and the inner hole is a longitudinal hole extending vertically, in the state with the cap member facing downward, and the shutter hole is a lateral hole with the axis thereof crossing the axis of the inner hole substantially at right angles. As a result, the shutter member does not go into the container, thereby preventing a large amount of residual toner. 
     According to the present invention, an opening diameter of the inner hole is smaller than that of the shutter hole, in the communicating portion between the inner hole and the shutter hole. 
     According to the present invention, since the opening diameter of the inner hole is smaller than that of the shutter hole, in the communicating portion between the inner hole and the shutter hole, the opening for draining the toner can be reliably closed by the shutter member inserted into the shutter hole. 
     According to the present invention, a narrowed portion is formed in the inner hole, with the cross-sectional area of the opening decreasing toward the shutter hole. 
     According to the present invention, since the narrowed portion in which the cross-sectional area of the opening decreases toward the shutter hole is formed in the inner hole, the toner can be discharged smoothly and supplied. 
     According to the present invention, the cap member includes an upper body portion and a lower body portion. The upper body portion is provided with a storage-fixing portion to which the storage member is fixed. The lower body portion is provided with the shutter hole, and the lower body portion is formed substantially in a rectangular parallelepiped with the width between the front and back surfaces being formed thinner than the width between the opposite sides. 
     According to the present invention, the cap member includes the upper body portion and the lower body portion, the upper body portion is provided with the storage-fixing portion to which the storage member is fixed, the lower body portion is provided with the shutter hole, and the lower body portion is formed substantially in a rectangular parallelepiped with the width of the front and back surfaces being formed thinner than the width between the opposite sides. As a result, setting of the toner container to the proper position can be facilitated. 
     According to the present invention, a taper, the width of which becomes narrow toward the lower part, is formed on the opposite sides of the lower body portion. 
     According to the present invention, since the taper, the width of which becomes narrow toward the lower part, is formed on the opposite sides of the lower body portion, setting of the toner container to the proper position can be facilitated. 
     According to the present invention, the shutter hole is a through hole going through from the front surface through to the back surface of the lower body portion, and the shutter member can pass through the shutter hole. 
     According to the present invention, since the shutter hole is a through hole going through from the front surface through to the back surface of the lower body portion, the width of the cap member between the front and back surfaces can be made thinner. 
     According to the present invention, the width of the cap member between the front and back surfaces is equal to the axial width of the shutter member. 
     According to the present invention, since the width of the cap member between the front and back surfaces is equal to the axial width of the shutter member, there is no possibility that the shutter member obstructs installation of the toner container. 
     The toner container according to the present invention further includes a sealing unit that seals the shutter hole, into which the shutter member is inserted. 
     According to the present invention, since the sealing unit for sealing the shutter hole, into which the shutter member is inserted, is provided, toner leakage can be reliably prevented, and a toner supply path can be made a sealed passage. 
     According to the present invention, the shutter hole is circular in cross section, and the sealing unit is an O-ring having resilience, provided at the end of the shutter hole. 
     According to the present invention, since the shutter hole is circular in cross section and the sealing unit is an O-ring having resilience, provided at the end of the shutter hole, uniform sealing force can be applied over the whole circumference thereof at a reasonable cost. 
     According to the present invention, the sealing unit is provided in the shutter member. 
     According to the present invention, since the sealing unit is provided in the shutter member, it is not necessary to provide a seal holding unit in the cap member. 
     According to the present invention, the cap member includes a middle part having an engaging groove, with which the sealing unit is engaged; and an external part having a fitting portion to which the middle part is fitted, a storage-fixing portion to which the storage member is fixed, and a holding portion for holding the sealing unit engaged with the engaging groove. 
     According to the present invention, the cap member includes the middle part and the external part, the middle part is provided with the engaging groove with which the sealing unit is engaged, and the external part is provided with the fitting portion to which the middle part is fitted, the storage-fixing portion to which the storage member is fixed, and the holding portion for holding the sealing unit engaged with the engaging groove. As a result, the sealing unit can be easily assembled, and reliably held. 
     According to the present invention, the shutter hole is formed in the cap member, spanned over the middle part and the external part, and the cap member is assembled by inserting the shutter member into the shutter hole, with the sealing unit held by the middle part and the external part. 
     According to the present invention, the shutter hole is formed in the cap member, spanned over the middle part and the external part, and the cap member is assembled by inserting the shutter member into the shutter hole, with the sealing unit held by the middle part and the external part. As a result, a member or means for binding the middle part and the external part is not required. 
     According to the present invention, the inner hole provided in the cap member is formed, spanned over the middle part and the external part, and a narrowed portion formed in the inner hole, with the cross-sectional area of the opening decreasing toward the shutter hole, is formed in the middle part. 
     According to the present invention, the inner hole provided in the cap member is formed, spanned over the middle part and the external part, and the narrowed portion formed in the inner hole, with the cross-sectional area of the opening decreasing toward the shutter hole, is formed in the middle part. As a result, by detaching the middle part, the toner can be filled easily. 
     According to the present invention, the cap member includes an upper part having a storage-fixing portion to which the storage is fixed; an inner part having an engaging groove with which the sealing unit is engaged; and a lower part having a fitting portion to which the inner part is fitted, and a holding portion for holding the sealing unit engaged with the engaging groove. 
     According to the present invention, the cap member includes the upper part, the inner part, and the lower part, wherein the storage-fixing portion to which the storage is fixed is provided in the upper part, the engaging groove with which the sealing unit is engaged is provided in the inner part, and the fitting portion to which the inner part is fitted, and the holding portion for holding the sealing unit engaged with the engaging groove are provided in the lower part. As a result, the sealing unit is easily assembled and reliably held, and when the toner container is disposed, only the bag-like container and the upper part are disposed, and the inner part and the lower part can be reused. 
     According to the present invention, the cap member includes a coupling unit that detachably couples the upper part and the lower part. The sealing unit is held by fitting the inner part to the fitting portion in the lower part, and the cap member is assembled by coupling the lower part that holds the sealing unit by fitting of the inner part, to the upper part by the coupling unit. 
     According to the present invention, the cap member is provided with the coupling unit that detachably couples the upper part and the lower part, the sealing unit is held by fitting the inner part to the fitting portion in the lower part, and the cap member is assembled by coupling the lower part that holds the sealing unit by fitting of the inner part, to the upper part by the coupling unit. As a result, the assembly work is facilitated, and the assembly can be completed by the operation of one action after filling the toner. 
     According to the present invention, the coupling unit includes a fixed guide provided on the lower opposite sides of the upper part, and a guide support provided on the upper opposite sides of the lower part, and the fixed guide and the guide support are engaged with each other by the rotation of one of the upper part and the lower part with respect to the other thereof. 
     According to the present invention, the coupling unit includes the fixed guide provided on the lower opposite sides of the upper part, and the guide support provided on the upper opposite sides of the lower part, and the fixed guide and the guide support are engaged with each other by the rotation of one of the upper part and the lower part with respect to the other thereof. As a result, the assembly work is facilitated. 
     According to the present invention, the rotation of one of the upper part and the lower part with respect to the other thereof for allowing the engagement of the fixed guide with the guide support is a rotation about the axis of the inner hole. 
     According to the present invention, since the rotation of one of the upper part and the lower part with respect to the other thereof for allowing the engagement of the fixed guide with the guide support is a rotation about the axis of the inner hole, a deviation hardly occurs in the inner hole due to the coupling of the upper part and the lower part. 
     According to the present invention, the fixed guide and the guide support include a locking unit that locks the upper part and the lower part when the upper part and the lower part are coupled properly. 
     According to the present invention, since the fixed guide and the guide support are respectively provided with the locking unit that locks the upper part and the lower part when these are coupled properly, the assembly accuracy is improved, thereby preventing defective assembly. 
     According to the present invention, the inner hole provided in the cap member is formed, spanned over the upper part and the inner part, and a narrowed portion formed in the inner hole, with the cross-sectional area of the opening decreasing toward the shutter hole, is formed in the inner part. 
     According to the present invention, the inner hole provided in the cap member is formed, spanned over the upper part and the inner part, and the narrowed portion formed in the inner hole, with the cross-sectional area of the opening decreasing toward the shutter hole, is formed in the inner part. As a result, the toner can be filled easily in the state that there are no inner part and lower part. 
     An image forming apparatus according to still another aspect of the present invention includes a storage member that stores a toner; and a cap member integrally formed with or fixed to the storage member, and having an opening for draining the toner. The opening for draining the toner includes an inner hole on the storage member side; and a shutter hole through which a shutter member can be inserted or taken out, with the inner hole and the shutter hole being communicated with each other with an angle. When the storage member is set in a main body of the image forming apparatus, the shutter member is shifted by a nozzle provided in the main body. 
     According to the present invention, when the toner container having the storage member that stores toner, and the cap member integrally formed with or fixed to the storage member, and having the opening for draining the toner formed therein, in which the opening for draining the toner has the inner hole on the storage member side, and the shutter hole through which the shutter member can be inserted or taken out, with the inner hole and the shutter hole being communicated with each other with an angle, is set in the apparatus body, the shutter member is shifted by the nozzle provided in the apparatus body. Therefore, the shutter member does not go into the container, thereby providing an image forming apparatus using the toner container that prevents a large amount of residual toner. 
     A powder container according to still another aspect of the present invention a bag-like powder storage having an opening at one end; a draining port for draining the powder stored in the powder storage to outside; and a powder draining member mounted on the opening of the powder storage. The powder draining member includes a draining port member in which a drain passage for leading the powder from the powder storage to the draining port is formed and having a shutter function of opening or closing the drain passage; and a base member fitted to the opening, to or from which the draining port member is coupled or detached. 
     According to the present invention, when the use of the powder container has finished, the draining port member can be detached from the used powder container, by a simple operation of releasing the engagement of the base member constituting the opening with the draining port member. Therefore, a complicated operation of detaching the bonded elastic sealing material in the toner draining member, which is required in the conventional toner container, is not necessary. Therefore, the bag-like container as the bag-like powder storage, the base member, and the draining port member can be easily recycled as an individual part. Further, the opening communicating with the inside of the bag-like container is exposed to the outside by the detachment of the draining port member, and the powder can be filled from the exposed opening. As a result, the bag-like container can be easily recycled by refilling the toner in the bag-like container. 
     According to the present invention, the base member has a powder passage through which the powder from the powder storage passes, and the opening area at the outlet of the powder passage on the draining port member side is larger than that of the draining port. 
     According to the present invention, the opening area at the outlet of the inner hole of the external part (upper part) as the base member is larger than that of the shutter hole as the powder draining portion in the middle part (inner part) as the draining port member. Thus, since the opening area at the outlet of the inner hole of the external part (upper part) is larger than that of the shutter hole in the middle part (inner part), the powder such as toner can be easily filled from the outlet of the inner hole of the external part (upper part) exposed by detaching the middle part (inner part). Further, since the opening area of the shutter hole in the middle part (inner part) can be kept small, leakage of the powder from the shutter hole can be suppressed. 
     According to the present invention, the base member has a powder passage through which the powder from the powder storage passes, and the powder passage is formed such that the cross-sectional area of the powder passage in a direction of a face orthogonal to the powder passing direction decreases from the opening side of the powder storage toward the draining port member side. 
     According to the present invention, the cross-sectional area of the opening of the inner hole as the powder passage in the external part (upper part) as the base member, in a direction of the face orthogonal to the toner passing direction decreases from the opening side of the bag-like container as the powder storage toward the middle part (inner part) as draining port member. Thus, since a narrowed portion is formed such that the cross-sectional area of the opening of the inner hole in the external part (upper part) gradually decreases, the residual toner in the inner hole can be reduced, and the powder such as toner received from the bag-like container side can be allowed to pass smoothly toward the middle part (inner part) side. 
     According to the present invention, a shutter member is provided, which is movable between a position for opening the inlet of the drain passage on the powder storage side and a position for closing the inlet. 
     According to the present invention, since the shutter member provided in the middle part (inner part) as the draining port member moves between the position for opening the inlet of the shutter hole as the drain passage on the bag-like container side and the position for closing the inlet, the shutter hole can be opened or closed. Therefore, leakage of the powder such as toner due to a drop in the righting moment of the elastic body, which has occurred heretofore when the conventional sealing material formed of the elastic body is used, can be prevented. 
     According to the present invention, the drain passage is formed of a through hole opened to the outside of the powder container. 
     According to the present invention, since the shutter hole as the drain passage is a through hole opened to the outside of the toner container, the shutter member is shifted by inserting the nozzle for draining the toner, to automatically open the drain passage. 
     According to the present invention, at least a part of the powder passage from the powder storage to the draining port in the powder draining member is bent. 
     According to the present invention, the toner passage from the powder storage (bag-like container) to the draining port (cap member) is bent at one spot or more. Therefore, when the bag-like container is located above the cap member, the toner in the bag-like container does not move linearly toward the draining port by the gravity. Further, when the bag-like container is located above the cap member, since at least one part of the portion from the bent portion to the draining port of the passage for the powder such as toner inclines with respect to the perpendicular direction, the toner likely to move in the direction of gravity can be received by the internal wall of the inclined portion. Therefore, when the bag-like container is located above the cap member, leakage of powder such as toner from the draining port can be suppressed, at the time of setting or detaching the powder container. 
     According to the present invention, the base member has a powder passage through which the powder from the powder storage passes, and a direction of powder passing in a portion of the drain passage near the draining port is inclined with respect to a direction of powder passing in the powder passage. 
     According to the present invention, the passing direction of the powder such as toner near the draining port of the shutter hole is inclined with respect to the toner passing direction in the inner hole as the powder passage in the external part (upper part) as the base member. Therefore, when the powder container is detached in the state that the bag-like container is located above the draining port member, the internal wall of the shutter hole near the draining port is inclined with respect to the perpendicular direction. Accordingly, the toner likely to move in the direction of gravity near the draining port of the shutter hole can be received by the internal wall near the draining port of the shutter hole, and hence toner leakage from the draining port can be further suppressed at the time of setting or detaching the powder container. 
     According to the present invention, the powder storage is formed of a flexible material. 
     According to the present invention, since the powder container (bag-like container) is formed of a flexible material, after the use of the powder container has finished, the bag-like container can be deformed so as to reduce the volume thereof. As a result, the volume of the used powder container can be reduced. 
     A method of recycling a used powder container according to still another aspect of the present invention includes releasing an engagement of a base member with a draining port member in the used powder container to detach the draining port member from the base member; filling a powder into the powder storage from an exposed opening of the base member; and coupling the base member to the draining port member after filling the powder. 
     According to the present invention, when the use of the powder container has finished, the engagement between the base member and the draining port member constituting the powder draining member is released. By a simple operation of releasing the engagement of these members, the draining port member can be detached from the used powder container. Therefore, a complicated work for detaching the bonded sealing material formed of the elastic body in the powder draining member as required in the conventional powder container is not necessary. As a result, recycling of the powder storage, the base member, and the draining port member as individual parts can be facilitated. Further, the opening communicating with the inside of the powder storage is exposed to the outside by the detachment of the draining port member, and the powder can be filled from the exposed opening. As a result, the powder storage can be easily recycled by refilling the powder in the powder storage. 
     A method of recycling a used powder container according to still another aspect of the present invention includes releasing an engagement of a base member with a draining port member in the used powder container to detach the draining port member from the base member; and coupling another base member fitted to a powder storage filled with new powder to the draining port member. 
     According to the present invention, when the use of the powder container has finished, the engagement between the base member and the draining port member constituting the powder draining member is released. By a simple operation of releasing the engagement of these members, the draining port member can be detached from the used powder container. Therefore, a complicated work for detaching the bonded sealing material formed of the elastic body in the powder draining member as required in the conventional powder container is not necessary. As a result, recycling of the powder storage, the base member, and the draining port member as individual parts can be facilitated. Further, after detaching the draining port member, another base member fitted to the bag-like container filled with the new toner may be engaged with the detached draining port member to couple these members. By reproducing the toner container in this manner, the draining port member can be recycled and reused. 
     A powder supplying unit according to still another aspect of the present invention includes a container mounting portion on which a powder container is mounted; and a powder supplying unit that supplies powder in the powder container to an apparatus to which the powder is to be supplied. 
     According to the present invention, by using the powder container in, for example, a toner supplying apparatus in a color laser printer, toner leakage from a container for storing the toner can be prevented, and recycling of the toner container can be easily performed. 
     An image forming apparatus according to still another aspect of the present invention includes a developing unit that develops a latent image on an image carrier by using a powder developer; and a developer supplying unit that supplies the developer to the developing unit. As for the developer supplying unit, a powder supplying unit according to the above aspect is used. 
     According to the present invention, by using the powder container in, for example, a toner supplying apparatus in a color laser printer, toner leakage from a container for storing the toner can be prevented, and recycling of the toner container can be easily performed. 
     A toner container according to still another aspect of the present invention includes a bag-like toner storage having an opening at one end; a toner stored in the toner storage; a draining port for draining the toner in the toner storage to the outside; and a drain passage for leading the toner from the toner storage to the draining port. At least a part of the drain passage from the toner storage to the draining port in the powder draining member is bent. 
     According to the present invention, a toner cartridge can be provided, in which toner leakage from the draining port at the time of detachment is suppressed, by storing the toner used in the image forming apparatus such as a copier, in the toner storage, and guiding the toner from the toner storage to a draining port through a drain passage. 
     A toner container according to still another aspect of the present invention includes a bag-like toner storage having an opening at one end; a refill toner refilled in the toner storage, after the toner stored in the toner storage has been exhausted at least once; a draining port for draining the refill toner in the toner storage to the outside; and a drain passage for leading the refill toner from the toner storage to the draining port. At least a part of the drain passage from the toner storage to the draining port in the powder draining member is bent. 
     According to the present invention, a refill toner cartridge can be provided, in which toner leakage from the draining port at the time of detachment is suppressed, by storing the refill toner to be used in the image forming apparatus such as a copier, when the toner in the toner storage has been exhausted at least once, and guiding the refill toner from the toner storage to the draining port through the drain passage. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an image forming apparatus using a toner container according to the present invention; 
         FIG. 2  is a cross section of a toner supplying apparatus in the image forming apparatus; 
         FIG. 3  is a perspective view of a state in which the toner is filled in the toner container according to the present invention; 
         FIG. 4  is a front elevation of a state in which the toner container is folded; 
         FIG. 5  is an exploded perspective view of one embodiment of a cap member of the toner container according to the present invention; 
         FIG. 6  is a cross section of the cap member in  FIG. 5 ; 
         FIG. 7  is a longitudinal cross section of the cap member in  FIG. 5 ; 
         FIG. 8  is an exploded perspective view of another configurational example of the cap member of the toner container according to the present invention; 
         FIG. 9  is a cross section of the cap member in  FIG. 8 ; 
         FIG. 10  is a longitudinal cross section of the cap member in  FIG. 8 ; 
         FIG. 11  is an outline view of the image forming apparatus shown in  FIG. 1 ; 
         FIG. 12  is an exploded perspective view of a setting unit of the toner container; 
         FIG. 13  is a cross section of a state in which an opening-closing folder of the setting unit shown in  FIG. 12  is closed; 
         FIG. 14  is a cross section of a state in which the opening-closing folder of the setting unit shown in  FIG. 12  is opened; 
         FIG. 15  is a lateral cross section of the setting unit shown in  FIG. 12 ; 
         FIG. 16  is a perspective view of an embodiment in which a nozzle and a slider are integrally formed; 
         FIG. 17  is an explanatory diagram of another embodiment of the setting unit of the toner container in the closed state; 
         FIG. 18  is an explanatory diagram of the setting unit in  FIG. 17  in the opened state; 
         FIG. 19  is an explanatory diagram of another configurational example of the setting unit of the toner container; 
         FIG. 20(   a ) is a front elevation of the cap member according to another modification example; 
         FIG. 20(   b ) is a partial side view of the cap member as seen from a direction of arrow I in  FIG. 20(   a ); 
         FIG. 21  is a cross section of a conventional toner container; 
         FIG. 22  is a cross section of the state at the time of setting the toner container shown in  FIG. 21 ; and 
         FIG. 23  is an explanatory diagram of a toner container having a conventional self-closing valve. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     First Embodiment 
     The present invention will be explained in further detail with reference to the accompanying drawings. 
       FIG. 1  is a schematic diagram of a color laser printer, being one example of an image forming apparatus according to the present invention. The color laser printer has a configuration such that an image forming unit  3  is arranged substantially at the center of an apparatus body  1 , and a paper feeder  2  is arranged below the image forming unit  3 . In the image forming unit, an intermediate transfer belt  7  is provided as an image carrier formed of an endless belt having flexibility and spanned over a plurality of rollers  4 ,  5 , and  6 . In the traveling side of the upper intermediate transfer belt  7  between the rollers  4  and  5 , image forming units  8 Y,  8 C,  8 M, and  8 BK as four image forming units are arranged opposite to the intermediate transfer belt  7 . 
     The four image forming units  8  respectively include a photosensitive drum as a latent image carrier abutting against the intermediate transfer belt  7 , and devices that execute the electrophotographic process such as charging, developing, and cleaning. The four image forming units  8 Y,  8 C,  8 M, and  8 BK are constructed to have the same configuration, but the color of the toner for development is different, that is, there are four colors of yellow, cyan, magenta, and black. Above the image forming unit  8 , an optical writing unit  9  is arranged as an optical writing means that irradiates optically modulated laser beams onto the respective surfaces of the photosensitive drums. The optical writing unit  9  may be individually provided for each image forming unit  8 ; however, it is advantageous in view of the cost to use a common optical writing unit  9 . 
     When the image forming operation is started, a toner image is formed on the photosensitive drum  10  in the respective image forming units  8  based on the electrophotographic process, and the toner image is transferred in a superimposed manner sequentially to the intermediate transfer belt  7  by a transfer unit, not shown. Thus, a full color toner image is carried on the surface of the intermediate transfer belt  7 . On the other hand, a transfer material formed of paper or a resin sheet is fed by the paper feeder  2 , and the transfer material is fed to the space between a secondary transfer apparatus  11  and the roller via a resist roller  10 , synchronized with the timing of the toner image. At this time, a transfer voltage of an opposite polarity to the toner charging polarity of the toner image on the surface of the intermediate transfer belt is applied to the secondary transfer apparatus  11 , and as a result, the full color toner image on the surface of the intermediate transfer belt is collectively transferred onto the transfer material. When the transfer material, onto which the toner image is transferred, passes a fixing apparatus  12 , the toner image is dissolved due to the heat and pressure and fixed on the transfer material. The transfer material on which the image is fixed is ejected to a paper delivering unit  13  outside of the image forming apparatus body  1 . Alternately, a monochrome image can be formed by using any one of the image forming unit  8 , or a two- or three-colored image can be formed. 
       FIG. 2  is a cross section of a toner supply mechanism in a first embodiment of the present invention. In  FIG. 2 , reference sign  20  denotes a toner container in which a new toner is stored as a toner, and as shown in  FIGS. 2 and 3 , the toner container  20  is formed of a bag-like container  21 , being the toner container, and a cap member  30  having only one toner draining unit. The specific configuration of the toner container  20  will be explained later in detail. 
     The toner container  20  set in a printer body  1  is communicated with a developing unit  14  via a toner supply path. In the toner supply path, a nozzle  110  as a coupling member coupled to the cap member  30 , a powder pump  60  as a sucking unit that transports the toner in the container to the developing unit  14  by a suction force and a toner transfer tube  65  that connects the nozzle  110  and the powder pump  60  are provided. 
     In the developing unit  14 , screws  15  and  16  having spiral fins referred to as a transfer auger rotate in the direction of arrows C and D in the casing thereof, and a developer in which the toner and a carrier are mixed is stored therein. For example, the transfer auger is formed such that the screw  15  transfers the developer from this side to the other side in the figure, and the screw  16  transfers the developer from the other side to this side, and the developer is stirred while circulating, by providing a portion without a partition  17  at the center on the other side and this side. A part of the circulating developer is sucked up and attracted by a magnetic force of a developing roller  19 , regulated to a uniform thickness by a doctor blade  18 , and then comes in contact with a photoconductor. As a result, an electrostatic latent image on the photoconductor is developed by the toner to form a toner image. Only the toner adheres to the photoconductor, and development is performed, while supplying the toner thereto in a small amount from a toner supply port  68 , in order to maintain the amount of the toner in the developer circulating in the developing device constant. 
     The powder pump  60  is a so-called monoaxial screw pump and includes two main parts, that is, a rotor  61  and a stator  62 . In the rotor  61 , a hard axial member, circular in cross section, is formed in spirally twisted shape, and is connected to a motor  66  via a universal joint  64 . On the other hand, the stator  62  is made of a rubber-like flexible member and has a hole with the elliptical cross section being spirally twisted. The spiral pitch of the stator  62  is of a length twice as long as that of the rotor  61 . By fitting these two parts to each other and rotating the rotor  61 , the toner coming into a space between the rotor  61  and the stator  62  can be transferred. 
     When the rotor  61  in the thus configured powder pump  60  is rotated, the toner in the toner container  20  comes from a toner suction port  63  into the powder pump  60  and is sucked and transferred from left to right in the  FIG. 2 , and drops downward from a toner draining port  67  via the toner supply port  68 . The dropped toner is supplied to the developing unit  14 . 
     As shown in  FIG. 3 , the bag-like container  21  of the toner container  20  has flexibility, includes two sheets  21   a  and  21   b  constituting front and back surfaces, two sheets  21   c  and  21   d  constituting left and right sides, and an upper surface sheet  21   e , and is formed by fusing these sheets. In the sheets  21   c  and  21   d  on the left and right sides, a fold  22  for folding inward of the container is formed, and when the toner is filled, the fold  22  expands to form the container shape, and when the container is empty, the sheets  21   c  and  21   d  are folded along the fold  22 , with the front and back sheets  21   a  and  21   b  sticking or becoming adjacent to each other. 
     If the size of the bag-like container  21  is automatically reduced, not manually, when the bag-like container  21  becomes empty, the labor for folding the bag-like container  21  can be omitted, and advantageously, toner scattering can be prevented at the time of folding. In the toner supply mechanism, if airtightness is maintained in the toner supply path from the toner container  20  to the powder pump  60 , automatic reduction can be easily realized. However, automatic reduction has problems other than keeping the airtightness. One of the problems is to make the form of the toner container  20  after reduction substantially the same. If the form after reduction is not uniform, labor for uniformalization is required, canceling the effect in automatic reduction. 
     The most effective method of uniformalizing the form of the toner containers  20  after reduction is to provide the fold  22 . However, if the fold  22  is provided, there is a problem in that the toner is put between the front and back sheets  21   a  and  21   b , and the folded left and right side sheets  21   c  and  21   d , does not drop to the draining port at the lowermost position and is held halfway, and hence the toner cannot be discharged, causing residual toner. 
     In order to solve such a problem, it is effective to provide, in the toner container  20 , a slope respectively on the front and back surfaces and the left and right sides, so that the cross-sectional area decreases toward the draining port at the bottom, and it has been found that the degree of inclination of the slope is important. It is also found that the degree of inclination is largely related to the flowability of the toner. In other words, the toner having excellent flowability moves to the draining port even if the angle of inclination is small; however a large angle of inclination is required for the toner having poor flowability. 
     Therefore, the present inventor has made an intensive study of the relation between the flowability of the toner and the angle of inclination, from an angle of repose (an angle of slope of a mountain formed by dropped powder by letting the powder freely drop in a small amount), and it has been found that the residual toner due to volume reduction can be considerably reduced by setting the angle of the slope on the sides larger than the angle of repose, when the toner container  20  is expanded. In other words, it is effective to set an angle S shown in  FIG. 3  larger than the angle of repose of the toner, and the angle S has a relation of:
 
 S ′=Tan −1 (1/cos φ),
 
where φ denotes the angle of repose of the toner, and S′ is an angle of a weld on the side in the state that the toner container  20  shown in  FIG. 4  is folded. For example, when the angle of repose of the toner is 40°,
 
 S ′=Tan −1 (1/cos 40)=52.55°,
 
and when the weld is formed at an angle of 52.55° or more, the angle S in the expanded state becomes 40° or more. The angle of repose of the toner “imagio toner type 15”, produced by Ricoh Company, Ltd., is 30.5°, and according to the above equation, S′ becomes 49.3°. However, since the toner tends to deteriorate in flowability according to the environment (temperature, humidity, and the like), it is preferable to set the angle S′ larger than that by 2 to 5°. Considering only the residual toner, the angle S′ may be set to an angle as large as, for example, 60° or more. However, when the angle S′ is set large, the stored amount of the toner per unit area occupied by the container decreases. Therefore, it is preferable that the angle of the slope on the sides when the toner container  20  is expanded slightly exceeds the angle of repose of the toner.
 
     As shown in  FIGS. 5 to 7 , the cap member  30  includes an upper body portion  31  and a lower body portion  40 , and a storage-fixing portion  32  is provided in the upper body portion  31 , to which the bag-like container  21  formed in a boat shape as seen from above is welded. The lower body portion  40  is substantially in a rectangular parallelepiped, and when it is assumed that the surface shown in  FIG. 5  is the front surface, a width Wa of front and back surfaces in the lower body portion  40  of the cap member  30  is set wider than a width Wb on the opposite sides. 
     In the cap member  30 , an opening for draining the toner is formed, which includes an inner hole  33  on the bag-like member  21  side and a shutter hole  41  communicated to the inner hole  33 , through which a shutter member described later can be inserted or pulled out. The inner hole  33  is a longitudinal hole extending in the vertical direction, with the cap member  30  facing downward, whereas the shutter hole  41  is a lateral hole, whose axis crosses the axis of the inner hole  33  substantially at right angles, and the shutter hole  41  in the present embodiment is a through hole circular in cross section going through from the front surface to the back face in the lower body portion  40 . The inner hole  33  is a hole circular in cross section, designating the length in a minor direction inside of the storage-fixing portion  32  having a boat shape as a diameter, and includes a funnel-shaped narrowed portion  33   a  formed halfway therein. That is, the inner hole  33  has a reduced diameter halfway by the narrowed portion  33   a  so that the opening area decreases toward the shutter hole  41 , and is communicated with the shutter hole  41  above thereof. Therefore, in a communicating portion between the inner hole  33  and the shutter hole  41 , the opening diameter of the inner hole  33  becomes smaller than that of the shutter hole  41 . When a shutter member  50  is inserted in the shutter hole  41 , the opening for draining the toner is reliably closed. 
     The shutter member  50  in the embodiment is formed in a circular shaft shape in cross section, and is formed to have a smaller diameter than that of the shutter hole  41 . As a result, the shutter member  50  can be reliably inserted in the shutter hole  41 . However if the diameter of the shutter member  50  is smaller than that of the shutter hole  41 , leakage of toner or air occurs from between the shutter member  50  and the shutter hole  41 . The toner leakage causes toner contamination and air leakage obstructs volume reduction of the toner container  20 . 
     In the cap member  30 , as shown in  FIG. 8 , an O-ring  42  pentagonal in cross section is provided as a sealing unit that seals between the cap member  30  and the shutter member  50 . Since, the shutter hole  41  is a through hole, the O-ring  42  is provided on the opposite sides of the shutter hole  41 . The O-ring  42  may be fitted by forming a groove, in which the O-ring  42  is fitted, on the opposite sides of the shutter hole  41  and fixing by bonding. However, time and labor are required for fixing the O-ring  42 , thereby causing a problem in that the assembly cost increases. 
     Therefore, the cap member  30  in the embodiment shown in  FIGS. 5 to 7  is divided into a middle part  43  and an external part  34 , and the O-ring  42  is held by engagement of these parts. Specifically, the middle part  43  is provided with an engaging groove  44  through which the O-ring  42  is connected to the middle part  43 , and the external part  34  is provided with a fitting portion  35  to which the middle part  43  is fitted, the storage-fixing portion  32 , a holding portion  36  for holding the O-ring  42  engaged with the engaging groove  44 . When the middle part  43  is fitted to the external part  34  via the O-ring  42 , with the O-ring  42  engaged with the engaging groove  44 , the O-ring is pressed by the holding portion  36 , thereby reliably preventing the O-ring  42  from coming off. 
     The shutter hole  41  is formed across the middle part  43  and the external part  34 . The middle part  43  is fitted to the fitting portion  35  of the external part  34 , and the shutter member  50  is inserted in the shutter hole  41 , thereby attaching the meddle part  43  to the external part  34 . By a simple operation of pulling out the shutter member  50 , the cap member  30  can be disassembled into the external part  34  and the middle part  43 . Since the toner spills when the shutter member  50  is pulled out in the state with the toner filled in the toner container  20 , the diameter thereof is suppressed to about 8 mm at most, and the diameter is preferably 6 mm, since the shutter member  50  is hardly moved by a finger with this size of diameter. In other words, if it is assumed that the diameter of the shutter member  50  is 10 mm, there is the possibility that the shutter member  50  is moved by a finger of an adult, thereby causing toner leakage. Therefore, the diameter of the shutter member  50  is set to 8 mm or less. 
       FIGS. 8 to 10  are exploded perspective views of another configurational example of the cap member  30 , and the cap member  30  in the present embodiment is formed of three parts of an upper part  37 , an inner part  45 , and a lower part  46 . The upper part  37  is provided with the storage-fixing portion  32  to which the bag-like member  21  is fixed and a fixed guide  38  as an engaging means that engages with the lower part. The inner part  45  is provided with the engaging groove  44  with which the O-ring  42  is engaged, and the fitting portion  35  for the inner part  45 , the holding portion  36  for the O-ring  42 , and a guide support  47  for the fixed guide  38  in the upper part  37  are provided in the lower part  46 . 
     In the cap member  30 , the shutter hole  41  is formed across the inner part  45  and the lower part  46 , and the inner part  45  in which the O-ring  42  is engaged with the engaging grove  44  is fitted to the fitting portion  35  in the lower part  46 , and by inserting the shutter member  50  in the shutter hole  41 , the inner part  45  is attached to the lower part  46 . The upper part  37  and the lower part  46  are couple to each other by rotating the fixed guide  38  in the upper part  37  so as to fit to the guide support  47 , thereby completing the assembly of the cap member  30 . At this time, the cap member  30  is provided with a locking unit that is locked when the upper part  37  and the lower part  46  are coupled to each other at the proper position. The locking unit in the present embodiment includes a locking claw (not shown) provided in the upper part  37  and a locking groove  46   a  provided in the lower part  46 , and when these parts are coupled to each other at the right position, the locking claw fits into the locking groove  46   a . The inner hole  33  is formed across the upper part  37  and the inner part  45 . Since the upper part  37  and the lower part  46  are coupled to each other by the rotation operation about the axis of the inner hole  33 , the inner hole  33  is not deviated. 
     In the cap member  30  in the embodiment, with two parts, the inner hole  33  extends over the external part  34  and the middle part  43 , and with three parts, the inner hole  33  extends over the upper part  34  and the inner part  43 . The funnel-shaped narrowed portion  33   a  is formed in the inner hole  33 , and in the both embodiments, the funnel-shaped narrowed portion  33   a  is formed in the middle part  43  and the inner part  45 , being the inside part. 
     The toner is filled in the toner container  20  in a factory, however, in the toner container  20 , it is difficult to fill the toner from the shutter hole  41 , since it is via the inner hole  33  facing a different direction. Further, filling by forming a filling opening in the bag-like container  21  itself, and by using this opening is also difficult, because the container expands due to the filled toner, and hence sealing of the container is difficult. Therefore, in the toner container  20  in the above two embodiments, before the middle part  34  or the inner part  45  is fitted, the inner hole  33  is a relatively large opening, because the narrowed portion  33   a  is not formed in the inner hole  33 . 
     Therefore, if the toner is filled before the middle part  34  or the inner part  45  is fitted, the filling operation can be easily conducted, and thereafter, by fitting the middle part  34  or the inner part  45 , the container becomes the sealed state. Thus, if the cap member  30  is formed of the two parts or the three parts, filling of the toner becomes easy. 
     The toner container  20  using the two-part cap member  30  requires two actions of fitting the middle part  43  to the external part  34  after filling the toner, and inserting the shutter member  50  therein. However, with the toner container  20  using the three-part cap member  30 , by fitting the inner part  45  to the lower part  46 , and inserting the shutter member  50  therein beforehand, only one action of coupling the lower part  46  to the upper part  37  is required after filling the toner, and hence it is more preferable. 
     The configuration of the fitting portion of the toner container  20  having the above configuration to the image forming apparatus body  1  will be explained. 
     In the image forming apparatus in the embodiment, as shown in  FIG. 11 , setting units  100  to which the toner containers  20  for the four color toners are respectively fitted are provided. Only the setting unit  100  for black is formed in a wider size than that of other setting units, but the internal configuration is substantially the same. As shown in  FIGS. 12 and 13 , an opening-closing folder  103  fitted to a machine frame  101  of the apparatus body via a rotation shaft  102  is provided in the setting unit  100 , and the opening-closing folder  103  is rotatably supported by machine frame  101  between a closing position shown in  FIG. 13  and an opening position shown in  FIG. 14 . In the lower part of the opening-closing folder  103  are formed, as shown in  FIG. 15 , a pair of guide members  104  that slidably support the nozzle  110 , and a guide cylinder  105  to which a slider  106  that returns the inserted nozzle  110  is slidably fitted, and a fixed cover  115  is fitted on the outer surface thereof. In the upper part of the opening-closing folder  103 , an opening and closing handle  120  is installed movably in the vertical direction, which is provided with a locking unit  121  that holds the opening-closing folder  103  at the closing position, when the opening-closing folder  103  is shifted to the closing position. The opening and closing handle  120  is made of resin, and has an integrally formed resilient arm  122  below the handle  120 . The opening and closing handle  120  is held at the uppermost position by the resilient arm  122  at all times. The nozzle  110  is formed in the same diameter as that of the shutter member  50 . 
     On the nozzle  110 , an integrally formed slide arm  111  is respectively provided on the opposite sides thereof, and the slide arm  111  is movably fitted to the guide member  104 . At the point of the slide arm  111 , a locking claw  112  is provided, and the locking claw  112  is locked at the end of the guide member  104 , thereby preventing the nozzle  110  from coming off from the opening-closing folder  103 . Further, a compression spring  113  is fitted loosely so as to wrap around the nozzle  110  between the nozzle  110  and the opening-closing folder  103 . By this spring  113 , the nozzle  110  is held with resiliency at all times, at a position where the locking claw  112  is locked at the end of the guide member  104 . 
     The guide cylinder  105  has a cylindrical shape extending on the axis of the nozzle  110 , and a hole  105   a  into which the shutter member  50  can be inserted is formed at the end opposite to the nozzle  110 . The opposite end is closed by the fixed cover  115 . The slider  106  and the compression spring  107  that pushes the slider  106  toward the nozzle  110  are enclosed in the guide cylinder  105 . The slider  106  is formed in a convex shape in cross section, and is held within the guide cylinder  105  by a stopper  108  formed at the end on the nozzle side of the guide cylinder  105 , even when the slider  106  is pushed by the compression spring  107 . The opening-closing folder  103  is provided with a guide frame  109  that leads the inserted toner container  20  to the set position, and the nozzle  110  is arranged at the lowermost part of the guide frame  109 , thereby forming a support to which the lower body portion  40  of the cap member  30  of the toner container  20  is fitted. An opening, not shown, through which the nozzle  110  and the shutter member  50  can pass is formed in the support. 
     In the thus configured setting unit  100 , when the opening and closing handle  120  is pulled forward while being pushed down, the locking unit  121  comes off from the locking groove  123  formed in the machine frame  101 , and hence, as shown in  FIG. 14 , the bottom of the opening-closing folder  103  can be rotated about the rotation shaft  102  up to the position where the bottom of the opening-closing folder  103  abuts against the machine frame  101 , so that the opening-closing folder  103  is shifted to the opening position. The opening-closing folder  103  at the opening position is in the state that the nozzle  110  is pulled to the left side in  FIG. 14 . Here, when the toner container  20  is dropped with the cap member  30  side facing downward, since the nozzle  110  is held at a position where the engaging claw  112  abuts against the guide member  104  by the compression spring  113 , the shutter member  50  in the cap member  30  drops to a position opposite to the nozzle  110 . 
     After the toner container  20  is dropped to a predetermined position, the opening-closing folder  103  is returned to the original closing position shown in  FIG. 13 . By this returning action, the nozzle  110  is fitted into the shutter hole  41 , and the shutter member  50  is shifted from the hole  105   a  toward the guide cylinder  105 . A toner receiving port  114  is provided on the nozzle  110 , on the upper part of the periphery thereof near the end, and the toner receiving port  114  communicates with the lower part of the inner hole  33  provided in the cap member  30 , thereby forming a toner supply path from the toner container  20  to the developing unit  14 . 
     The shutter member  50  pushed out toward the guide cylinder  105  by the insertion of the nozzle  110  is held at a position spanning over the shutter hole  41  and the guide cylinder  105 , without coming off completely from the shutter hole  41 . 
     When the nozzle  110  is inserted in the shutter hole  41 , the compression spring  113  is pushed by the opening-closing folder  103  and compressed, and the compression spring  107  provided in the guide cylinder  105  is also compressed via the slider  106  by the insertion of the shutter member  50 . Therefore, when the opening-closing folder  103  is shifted from the closing position to the opening position, the nozzle  100  and the shutter member  50  are returned to the original position, respectively, by the resilient force of the compression spring  113  and the compression spring  107 . As a result, the nozzle  110  comes off from the shutter hole  41  in the toner container  20 , and the shutter member  50  is again inserted in the shutter hole  41 . 
     Only by setting the toner container  20  in the apparatus body  1 , the toner container  20  communicates with the toner supply path, and when the opening-closing folder  103  is opened, the nozzle  110  comes off from the shutter hole  41 . At this time, however, since the shutter member  50  is returned to the shutter hole  41  immediately, the toner does not leak from the toner container  20 . 
     In the embodiment, at the time of setting the toner container  20 , the nozzle  110  and the slider  106  are shifted in the same direction by the same amount. Therefore, as shown in  FIG. 16 , the nozzle  110  and the slider  106  may be integrally formed. This configuration can avoid such a problem that even if the nozzle  110  is pulled out, the slider  106  does not move, and hence, the shutter member  50  does not close the shutter hole  41 . 
       FIGS. 17 and 18  are another configurational example of the setting unit, in which the opening-closing folder  103  can be slid in a direction of arrow E by a linear guide unit, and is opened or closed with respect to the apparatus body  1  by the slide. 
     The opening-closing folder  103  is fitted to the apparatus body  1  via the linear guide  130 , and as shown in  FIG. 18 , when the opening-closing folder  103  is pulled out, the nozzle  110  is detached from the cap member  30 , so that the toner container  20  can be detached. In this state, when the toner container  20  is replaced by a new one and the opening-closing folder  103  is dropped therein, the nozzle  110  is set to the cap member  30 , and the toner can be supplied to the developing unit. 
       FIG. 19  is another configurational example of the setting unit, in which the opening-closing folder  103  is fixed to the apparatus body  1  and does not move. On the other hand, a door  140  is provided at the top thereof for detaching the toner container  20 . A nozzle support member  116  that supports the nozzle  110  is supported so as to be able to act directly in a direction of arrow F by a linear guide unit, not shown. The nozzle support member  116  is moved in the direction of arrow by a cam  141  rotating about a fulcrum  142 . On the other hand, the door  140  rotates about a fulcrum  143 . 
     In such a configuration, by connecting the cam  141  and the door  140  by an arm  144  as shown in the figure, the rotation of the cam  141  is synchronized with opening or closing of the door  140 , so that the nozzle  110  can be detached or set. Therefore, when the door  140  is opened, the nozzle  110  is detached from the cap member  30 , so that replacement and detachment of the toner container  20  becomes possible. When the door  140  is closed, the nozzle  110  is set to the cap member  30  via the arm  144 , the cam  141 , and the nozzle support member  116 , so that the toner can be sucked and supplied. 
     According to the configuration of the present embodiment, a nozzle constituting a part of the toner supply path and coupled to the toner container is provided in the setting unit, and the fitting direction of the toner container to the setting unit and the coupling direction of the nozzle to the toner container are different. Therefore, an image forming apparatus in which the residual toner in the toner container is little can be provided. 
     According to the configuration of the present embodiment, the setting unit is provided with the opening-closing folder fitted to the apparatus body movably between the closing position at which the toner container is in the set state, and the opening position at which the toner container can be detached, and the toner container is supported by the opening-closing folder. As a result, the opening and closing operation of the opening-closing folder can be used for setting or detaching the nozzle. 
     According to the configuration of the present embodiment, since the toner container is dropped from above and supported by the opening-closing folder in the setting unit, setting of the toner container can be facilitated. 
     According to the configuration of the present embodiment, since the guide member that guides the toner container dropped into the opening-closing folder to the installation position is provided, the dropped toner container is guided to the proper setting position, thereby reducing a setting error. 
     According to the configuration of the present embodiment, since the nozzle is coupled to the toner container by the shift of the opening-closing folder from the opening position to the closing position, special operation for coupling the nozzle to the toner container is not necessary. 
     According to the configuration of the present embodiment, since the opening-closing folder is fitted to the apparatus body rotatably between the closing position and the opening position, detachment of the nozzle can be performed by using the rotation operation thereof. 
     According to the configuration of the present embodiment, since the opening-closing folder is fitted to the apparatus body slidably between the closing position and the opening position, detachment of the nozzle can be performed by using the sliding operation thereof. 
     According to the configuration of the present embodiment, since the locking unit that locks the opening-closing folder at the closing position is provided, the opening-closing folder can be reliably held at the closing position. 
     According to the configuration of the present embodiment, the toner container includes: the storage member that stores the toner; the cap member provided below the storage member and having a toner draining unit formed therein; and the shutter member that closes the toner draining unit, wherein the nozzle is inserted into the position of the shutter member and connected to the toner draining unit, by the shift of the opening-closing folder from the opening position to the closing position. As a result, the shutter member is shifted by the insertion of the nozzle, so that the toner can be supplied. 
     According to the configuration of the present embodiment, the opening-closing folder is provided with the returning unit that returns the shutter member shifted by the insertion of the nozzle to the original position for closing the toner draining unit. Therefore, when the nozzle is pulled out from the cap member, the shutter member closes the toner draining unit, to prevent toner leakage at the time of pulling out the nozzle. 
     According to the configuration of the present embodiment, the returning unit includes a slider slidable in the shift direction of the shutter member, and an elasticity applying member that applies an elastic force to the slider in a direction of returning the shutter member. As a result, the shutter member can be returned to the original position by the elasticity applying member. 
     According to the configuration of the present embodiment, since the nozzle is slidably supported by the opening-closing folder, it can be prevented that the nozzle abuts against the cap member and is not connected. 
     According to the configuration of the present embodiment, since the nozzle is formed integrally with the slider, such a problem that only the nozzle is pulled out and the shutter member does not return to the original position can be reliably prevented. 
     Second Embodiment 
     A second embodiment according to the present invention will be explained below. 
     An example of the image forming apparatus (color laser printer) according to the second embodiment is similar to that shown in  FIG. 1 . Further, the toner supply container, the toner supplying apparatus, and the setting unit are the same as those shown in  FIGS. 2 to 19 . Therefore, repeated explanation is omitted, and only a characteristic point of the second embodiment will be explained herein. 
     As shown in  FIG. 2 , a bag-like container  21  as the toner container  20  is formed of a sheet material, being the flexible material, and hence has flexibility. The bag-like container  21  includes, as shown in  FIG. 3 , two sheets  21   a  and  21   b  constituting front and back surfaces, two sheets  21   c  and  21   d  constituting left and right sides, and an upper surface sheet  21   e , and is formed by fusing these sheets. In the sheets  21   c  and  21   d  on the left and right sides, a fold  22  for folding inward of the container is formed, and when the toner is filled, the fold  22  expands to form the container shape, and when the container is empty, the sheets  21   c  and  21   d  are folded along the fold  22 , with the front and back sheets  21   a  and  21   b  sticking or becoming adjacent to each other. 
     On the detachment side of the nozzle of the shutter hole  41 , a draining port  41   a  for draining the toner in the toner container  20  toward the developing unit is provided. The draining port  41   a  is located at one end of the toner container  20 , and the direction of the opening is different from the direction directed from the other end to the one end of the toner container  20 . Particularly, in the present embodiment, the direction of the opening is at right angles with respect to the direction from the other end to the one end of the toner container  20 . 
     By inserting the shutter member  50  into the shutter hole  41 , the toner draining port  41   a  of the shutter hole  41  can be closed by the shutter member  50 . 
     When the cap member  30  is disassembled, after the upper part  37  is detached from the lower part  46 , a cylindrical takeout tool is inserted from a through hole  48  for disassembly formed on the lower wall of the lower part  46 , to push up the inner part  45 . As a result, the inner part  45  can be easily detached from the lower part  46 . 
     When the cap member  30  is formed of two parts, the inner hole  33  is formed, spanned over the external part  34  and the middle part  43 . On the other hand, when the cap member  30  is formed of three parts, the inner hole  33  spans over the upper part  37  and the inner part  45 . The funnel-shaped narrowed portion  33   a  is formed in the inner hole  33 , and in the both embodiments, the narrowed portion  33   a  is formed in the middle part  43  and the inner part  45 , being the inside part. 
     In the present embodiment, a circuit substrate  70  is fitted in the lower part  46 . The circuit substrate  70  has an electric circuit and a memory so as to confirm from the apparatus body side the installation of the toner container  20 , or the amount of the residual toner in the toner container  20 . When the toner container  20  is installed in the apparatus body, a joining terminal on the circuit substrate  70  comes in contact with a joining terminal on the apparatus body side, to transfer information between the circuit substrate  70  and the apparatus body, so as to confirm the installation of the toner container  20 , or the amount of the residual toner in the toner container  20 . 
     As described above, the toner is filled in the toner container  20  in a factory. However, in the toner container  20 , it is difficult to fill the toner from the shutter hole  41 , since it is via the inner hole  33  facing a different direction. Further, filling by forming a filling opening in the bag-like container  21  itself, and by using this opening is also difficult, because the container expands due to the filled toner, and hence sealing of the container is difficult. Therefore, in the toner container  20  in the above two embodiments, before the middle part  43  or the inner part  45  is fitted, the inner hole  33  is a relatively large opening, because the narrowed portion  33   a  is not formed in the inner hole  33 . Therefore, if the toner is filled before the middle part  43  or the inner part  45  is fitted, the filling operation can be easily conducted, and thereafter, by fitting the middle part  43  or the inner part  45 , the container becomes the sealed state. Thus, if the cap member  30  is formed of the two parts or the three parts, filling of the toner becomes easy, since the toner container  20  can be detached from a part as a powder draining member having a draining port. Here, the powder draining member is the middle part  43  in the example of the two-part cap member  30 , and the inner part  45  and the lower part  46  in the example of the three-parts cap member  30 . The toner container  20  using the two-part cap member  30  requires two actions of fitting the middle part  43  to the external part  34  after filling the toner, and inserting the shutter member  50  therein. However, with the toner container  20  using the three-parts cap member  30 , by fitting the inner part  45  to the lower part  46 , and inserting the shutter member  50  therein beforehand, only one action of coupling the lower part  46  to the upper part  37  is required after filling the toner, and hence it is more preferable. 
     The configuration of the fitting portion of the toner container  20  having the above configuration to the image forming apparatus body  1  will be explained next. 
     In the thus configured setting unit  100 , when the opening and closing handle  120  is pulled forward while being pushed down, the locking unit  121  comes off from the locking groove  123  formed in the machine frame  101 , and hence, as shown in  FIG. 14 , the bottom of the opening-closing folder  103  can be rotated about the rotation shaft  102  up to the position where the bottom of the opening-closing folder  103  abuts against the machine frame  101 , so that the opening-closing folder  103  is shifted to the opening position. The opening-closing folder  103  at the opening position is in the state that the nozzle  110  is pulled to the left side in  FIG. 14 . Here, when the toner container  20  is dropped with the cap member  30  side facing downward, since the nozzle  110  is held at a position where the engaging claw  112  abuts against the guide member  104  by the compression spring  113 , the shutter member  50  in the cap member  30  drops to a position opposite to the nozzle  110 . This position is an unset position of the toner container  20  at which the nozzle  110  is detached from the shutter hole  41 . 
     After the toner container  20  is dropped to a predetermined position, the opening-closing folder  103  is returned to the original closing position shown in  FIG. 13 . By this returning action, the nozzle  110  is fitted into the shutter hole  41 , and the toner container  20  is located at the installation position. Synchronized with this, the shutter member  50  is shifted from the hole  105   a  toward the guide cylinder  105 . A toner receiving port  114  is provided on the nozzle  110 , on the upper part of the periphery thereof near the end, and the toner receiving port  114  communicates with the lower part of the inner hole  33  provided in the cap member  30 , thereby forming a toner supply path from the toner container  20  to the developing unit  14 . The shutter member  50  pushed out toward the guide cylinder  105  by the insertion of the nozzle  110  is held at a position spanning over the shutter hole  41  and the guide cylinder  105 , without coming off completely from the shutter hole  41 . 
     As in the present embodiment, when the bag-like container  21  is formed of flexible sheets, in the conventional configuration in which it has been necessary to push the toner container  20  downward until the nozzle  110  is inserted in the toner draining port  41   a , at the time of installing the toner container, an unexpected force is applied to the toner container  20 . Hence, an unexpected deformation may occur in the bag-like container  21  of the toner container  20 , thereby applying an unexpected force to the toner inside thereof, or causing a distortion in the bag-like container  21  itself. When the bag-like container  21  is distorted, there is the possibility that the toner therein may be blocked by the internal surface of the container and remain in the container, and hence the toner is not used for the development and remains therein. 
     In the present embodiment, since the toner container  20  is just dropped from above, and it is not necessary to press the toner container  20  from above, and insertion or detachment of the nozzle  110  can be carried out by a sliding movement in the horizontal direction, it can be avoided that the bag-like container  21  is distorted, or the inside toner remains therein. 
     In the present embodiment, when the toner container  20  is installed in the image forming apparatus body, the toner draining port  41   a  is opened in a direction different from the direction of gravity. Particularly, in the present embodiment, the toner draining port  41   a  is opened toward the horizontal direction. Thus, by setting the direction of the toner draining port  41   a , even if the toner in the toner container  20  drops due to the gravity, the toner is unlikely to from the toner draining port  41   a  to the outside. In addition, at the time of supplying the toner to the developing unit, it is not necessary to take out the toner from the toner container  20  against the gravity, like when the toner draining port  41   a  faces upward than the horizontal direction. Accordingly, the effect of preventing the toner from leaking outside of the toner container  20  can be further increased, and an excessive force is not necessary when the toner is taken out from the toner container  20 . 
     In the present embodiment, the cap member  30  can be divided into two parts or three parts. However, instead of this, the whole toner container  20  including the bag-like container  21  and the cap member  30  may be integrally formed. When the whole toner container  20  is integrally formed, the number of parts can be reduced. For this, it can be considered to form a filling opening in the bag-like container  21  itself, in order to fill a new toner in the bag-like container  21 . 
       FIG. 20(   a ) is a front elevation of the cap member according to a modification example.  FIG. 20(   b ) is a side view of the cap member shown in  FIG. 20(   a ) as seen from a direction of arrow I in  FIG. 20(   a ). In these figures, the toner draining port  41   a  is provided on the left side in the figure, in order to install the opening-closing folder shown in  FIGS. 17 and 18  in the image forming apparatus body. The toner draining port  41   a  facing the horizontal direction is provided in the cap member, and a self-closing valve  150  is provided for inserting or detaching the nozzle into or from the toner draining port  41   a . A cross-shaped slit  150   a  is formed in the self-closing valve  150 , and when the nozzle  110  is inserted into the cross-shaped slit  201   a , the slit deforms so as to receive it, and when the nozzle  110  is pulled out, the slit is closed due to the righting moment of the sponge. 
     In the configuration in which the self-closing valve is provided in the conventional toner container  20 , the self-closing valve faces the direction of gravity. Therefore, when the righting moment of the sponge decreases due to curing at a low temperature or a creep deformation with the lapse of time, a slight gap may be generated in the slit in the self-closing valve, at the time of insertion or detachment of the nozzle. When a gap is generated, the toner may drop, leak from the gap, and scatter, in the conventional configuration. 
     On the other hand, in the cap member shown in  FIG. 20 , the toner draining port  41   a  is opened toward the horizontal direction. By setting the direction of the toner draining port  41   a  in this manner, even if a slight gap is generated in the slit  150   a  of the self-closing valve, the toner in the toner container  20  is unlikely to leak from the toner draining port  41   a  to the outside. 
     In the embodiment, the toner in the two-component developer including the toner and the carrier is consumed accompanying the image formation. Therefore, an example is explained, in which the present invention is applied to the toner container, the toner supplying apparatus, and the image forming apparatus, which are used to sequentially supply the toner by a consumed amount. However, the present invention is applicable not only to the apparatus that supplies only the toner, but also to the apparatus that supplies a developer, such as the one supplying the two-component developer including the toner and the carrier, or the one supplying a one-component developer including only the toner. 
     According to the present embodiment, since the toner passage from the bag-like container  21  to the draining port is bent at one spot or more, when the bag-like container  21  is located above the cap member  30 , the toner in the bag-like container  21  does not linearly move toward the draining port due to the gravity. Further, when the bag-like container  21  is located above the cap member  30 , since at least a part of the portion from the bent portion of the toner passage to the draining port inclines with respect to the perpendicular direction, the toner moving in the direction of gravity can be received by the internal wall of the inclined portion. Therefore, when the bag-like container  21  is located above the cap member  30 , leakage of the toner from the draining port can be suppressed, when the toner container  20  is detached. 
     Particularly, in the present embodiment, the toner passing direction in a portion near the draining port of the shutter hole  41  is inclined with respect to the toner passing direction in the inner hole  33  as the powder passage in the external part  34  (the upper part  37 ) as the base member. Therefore, when the toner container  20  is detached in the state with the bag-like container  21  located above the draining port member, the internal surface near the draining port of the shutter hole  41  inclines with respect to the vertical direction. As a result, the toner trying to move in the direction of gravity near the draining port of the shutter hole  41  can be received by the internal surface near the draining port of the shutter hole  41 , thereby further suppressing the toner leakage from the draining port, at the time of detaching the toner container  20 . 
     According to the present embodiment, since the bag-like container  21  is formed of a flexible material, after the toner container  20  has been used, the bag-like container  21  can be deformed so as to decrease the volume thereof, thereby enabling a reduction in size of the used toner container  20 . 
     According to the present embodiment, the shutter member  50  provided in the middle part  43  (the inner part  45 ) as the draining port member moves between the position where the inlet on the bag-like container  21  side of the shutter hole  41  as the drain passage is opened and the position where the inlet is closed, thereby enabling opening or closing of the shutter hole  41 . Therefore, toner leakage due to a decrease in the righting moment of the elastic body, which has occurred when the conventional sealing material formed of an elastic body is used, can be prevented. 
     According to the present embodiment, since the shutter hole  41  as the drain passage is a through hole opened to the outside of the toner container  20 , the shutter member  50  is shifted by the insertion of the nozzle for draining the toner, thereby enabling automatic opening of the drain passage. Further, since the shutter member  50  moving in the shutter hole  41  due to the insertion of the nozzle  110  does not come into the bag-like container  21  side, it can be prevented that a large amount of toner remains in the toner container  20 . 
     According to the present embodiment, the nozzle  110  is set to or detached from the shutter hole  41  according to opening or closing of the opening-closing folder  103 . As a result, the toner container  20  can be easily detached. 
     According to the present embodiment, the shutter member  50  is shifted to the position for closing the shutter hole  41 , synchronized with the detachment operation of the nozzle  110  from the shutter hole  41 . Therefore, the shutter hole  41  can be closed by the shutter member  50 , even when the nozzle  110  is detached from the shutter hole  41  at the time of setting or detaching the toner container, thereby preventing leakage of the toner and toner scattering more effectively. 
     Closing of the shutter hole  41  by the shutter member  50  is released, synchronized with the setting operation of the nozzle  110  to the shutter hole  41 . Therefore, opening or closing of the shutter hole  41  by the shutter member  50  can be automatically performed, synchronized with attachment or detachment of the nozzle  110  with respect to the shutter hole  41 . Accordingly, timing control for moving the shutter member is not necessary, thereby enabling easy prevention of toner scattering. 
     Further, the nozzle  110  and the shutter member  50  may be integrally formed, by which the shutter member  50  can close the shutter hole  41 , synchronized with the movement of the nozzle  110 . 
     According to the present embodiment, the opening-closing folder  103  is provided as the powder container supporting member that movably supports the toner container  20  between the set position where the nozzle  110  is set to the shutter hole  41  of the toner container  20 , and the detached position where the nozzle  110  is detached. As a result, the opening-closing folder  103  can be used for shifting the toner container  20  between the set position and the detached position. 
     According to the present embodiment, by dropping the toner container  20  from above, with the cap member  30  side facing downward, the toner container  20  can be supported at the predetermined position of the opening-closing folder  103 . As a result, setting of the toner container  20  to the opening-closing folder  103  can be performed by an easy operation of dropping the toner container  20 . 
     According to the present embodiment, a guide frame  109  that guides the inserted toner container  20  to the set position is provided in the opening-closing folder  103 . The dropped toner container  20  can be guided to a position where the nozzle  110  can be fitted to the toner draining port  41   a  thereof by the guide frame  109 , thereby reducing the possibility of an installation error of the toner container  20 . 
     According to the present embodiment, attachment or detachment of the nozzle  110  with respect to the shutter hole  41 , performed by the opening or closing operation of the opening-closing folder  103  can be performed by an easy operation of inserting or pulling out the nozzle  110  with respect to the shutter hole  41 . As a result, attachment or detachment of the nozzle  110  can be smoothly performed. 
     According to the present embodiment, opening or closing of the shutter hole  41  by the shutter member  50  is performed, synchronized with the detachment operation of the nozzle  110  with respect to the shutter hole  41 , performed by the opening or closing operation of the opening-closing folder  103 . Therefore, by the opening or closing operation of the opening-closing folder  103 , attachment or detachment of the nozzle  110 , and opening or closing of the shutter hole  41  by the shutter member  50  can be automatically performed. As a result, toner scattering can be prevented by an easy operation. 
     According to the embodiment shown in  FIGS. 13 and 14 , the compression spring  107  is used for biasing the shutter member  50  toward the toner draining port  41   a . Therefore, the shutter member  50  can be shifted to the closing position of the toner draining port  41   a  by a resilient biasing force of the compression spring  107 , and hence, it is not necessary to provide a drive for shifting the shutter member  50 . 
     In the above embodiment, a toner container that stores the toner as the powder is explained. However, the present invention is similarly applicable to a powder container that stores a two-component developer including the toner and the carrier, and a powder container that stores a powder of other types. 
     According to the configuration of the embodiment therefore, when the powder storage is located above the powder draining member, the toner in the powder storage does not move linearly toward the draining port due to gravity. Further, since at least a part of the portion from the bent portion of the powder passage to the draining port inclines with respect to the perpendicular direction, the toner moving in the direction of gravity can be received by the internal wall of the inclined portion. Therefore, when the powder storage is located above the powder draining member, leakage of the powder from the draining port can be reduced, when the powder storage is detached. 
     Third Embodiment 
     A third embodiment according to the present invention will be explained below. 
     An example of the image forming apparatus (color laser printer) according to the third embodiment is similar to that shown in  FIG. 1 . Further, the toner supply container, the toner supplying apparatus, and the setting unit are the same as those shown in  FIGS. 2 to 19 . Therefore, repeated explanation is omitted, and only a characteristic point of the third embodiment will be explained herein. 
     When the axial length of the shutter member  50  is longer than the width between the front and back surfaces of the cap member  30 , that is, the width Wb of the side, the shutter member  50  inserted into the shutter hole  41  protrudes from the cap member  30 , and obstructs the installation of the container. Therefore, it is preferable that the length of the shutter member  50  be equal to the width Wb. 
     In the configuration of the present embodiment, the toner draining port  41   a  has an inner hole  33  on the storage member side, and the shutter hole  41  through which the shutter member  50  can be inserted or taken out, with the inner hole  33  and the shutter hole  41  being communicated with each other with an angle, and the opening for draining the toner  41   a  is opened or closed by inserting or taking out the shutter member  50 . As a result, the shutter member  50  does not go into the container, thereby preventing a large amount of residual toner. 
     In the configuration of the present embodiment, the cap member  30  is provided in the lower part of the storage member, and the inner hole  33  is a longitudinal hole extending vertically, in the state with the cap member  30  facing downward, and the shutter hole  41  is a lateral hole with the axis thereof crossing the axis of the inner hole substantially at right angles. As a result, the shutter member does not go into the container, thereby preventing a large amount of residual toner. 
     In the configuration of the present embodiment, the opening diameter of the inner hole  33  is smaller than that of the shutter hole  41 , in the communicating portion between the inner hole  33  and the shutter hole  41 . As a result, the opening for draining the toner  41   a  can be reliably closed by the shutter member  50  inserted into the shutter hole  41 . 
     In the configuration of the present embodiment, the narrowed portion in which the cross-sectional area of the opening decreases toward the shutter hole  41  is formed in the inner hole  33 . As a result, the toner can be discharged smoothly and supplied. 
     In the configuration of the present embodiment, the cap member  30  includes the upper body portion  31  and the lower body portion  40 , the upper body portion  31  is provided with the storage-fixing portion  32  to which the storage member is fixed, the lower body portion  40  is provided with the shutter hole  41 , and the lower body portion  40  is formed substantially in a rectangular parallelepiped with the width of the front and back surfaces being formed thinner than the width of the opposite sides. As a result, setting of the toner container  20  to the proper position can be facilitated. 
     In the configuration of the present embodiment, since the taper, the width of which becomes narrow toward the lower part, is formed on the opposite sides of the lower body portion  40 , setting of the toner container  20  to the proper position can be facilitated. 
     In the configuration of the present embodiment, since the shutter hole  41  is a through hole going through from the front surface through to the back surface of the lower body portion  40 , the width of the cap member  30  between the front and back surfaces can be made thinner. 
     In the configuration of the present embodiment, since the width of the cap member  30  between the front and back surfaces is equal to the axial width of the shutter member  50 , there is no possibility that the shutter member  50  obstructs installation of the toner container  20 . 
     In the configuration of the present embodiment, since the sealing unit for sealing the shutter hole  41 , into which the shutter member  50  is inserted, is provided, toner leakage can be reliably prevented, and a toner supply path can be made a sealed passage. 
     In the configuration of the present embodiment, since the shutter hole  41  is circular in cross section and the sealing unit is an O-ring having resilience, provided at the end of the shutter hole, uniform sealing force can be applied over the whole circumference thereof at a reasonable cost. 
     In the configuration of the present embodiment, since the sealing unit is provided in the shutter member  50 , it is not necessary to provide a seal holding unit in the cap member  30 . 
     In the configuration of the present embodiment, the cap member  30  includes the middle part  43  and the external part  34 , the middle part  43  is provided with the engaging groove  44  with which the sealing unit is engaged, and the external part  34  is provided with the fitting portion  35  to which the middle part  43  is fitted, the storage-fixing portion  35  to which the storage member is fixed, and the holding portion  36  for holding the sealing unit engaged with the engaging groove  44 . As a result, the sealing unit can be easily assembled, and reliably held. 
     In the configuration of the present embodiment, the shutter hole  41  is formed in the cap member  30 , spanned over the middle part  43  and the external part  34 , and the cap member  30  is assembled by inserting the shutter member  50  into the shutter hole  41 , with the sealing unit held by the middle part  43  and the external part  34 . As a result, a member or means for binding the middle part  43  and the external part  34  is not required. 
     In the configuration of the present embodiment, the inner hole  33  provided in the cap member  30  is formed, spanning over the middle part  43  and the external part  34 , and the narrowed portion formed in the inner hole  33  is also formed in the middle part  43 , with the cross-sectional area of the opening decreasing toward the shutter hole  41 . As a result, by detaching the middle part  43 , the toner can be filled easily. 
     In the configuration of the present embodiment, the cap member  30  includes the upper part  37 , the inner part  45 , and the lower part  46 , wherein the storage-fixing portion  32  to which the storage is fixed is provided in the upper part  37 , the engaging groove  44  with which the sealing unit is engaged is provided in the inner part  45 , and the fitting portion  35  to which the inner part  45  is fitted, and the holding portion  36  for holding the sealing unit engaged with the engaging groove  44  are provided in the lower part  46 . As a result, the sealing unit is easily assembled and reliably held, and when the toner container  20  is disposed, only the bag-like container  21  and the upper part  37  are disposed, and the inner part  45  and the lower part  46  can be reused. 
     In the configuration of the present embodiment, the cap member  30  is provided with the coupling unit that detachably couples the upper part  37  and the lower part  46 , the sealing unit is held by fitting the inner part  45  to the fitting portion in the lower part  46 , and the cap member  30  is assembled by coupling the lower part  46  that holds the sealing unit by fitting of the inner part  45 , to the upper part by the coupling unit. As a result, the assembly work is facilitated, and the assembly can be completed by one action after filling the toner. 
     In the configuration of the present embodiment, the coupling unit includes the fixed guide  38  provided on the lower opposite sides of the upper part  37 , and the guide support  47  provided on the upper opposite sides of the lower part  46 , and the fixed guide  38  and the guide support  47  are engaged with each other by the rotation of one of the upper part  37  and the lower part  46  with respect to the other thereof. As a result, the assembly work is facilitated. 
     In the configuration of the present embodiment, the rotation of one of the upper part  37  and the lower part  46  with respect to the other thereof for allowing the engagement of the fixed guide  38  with the guide support  47  is a rotation about the axis of the inner hole  33 . As a result, a deviation hardly occurs in the inner hole  33  due to the coupling of the upper part  37  and the lower part  46 . 
     In the configuration of the present embodiment, the fixed guide  38  and the guide support  47  are respectively provided with the locking unit that locks the upper part  37  and the lower part  46  when these are coupled properly. As a result, the assembly accuracy is improved, thereby preventing defective assembly. 
     In the configuration of the present embodiment, the inner hole  33  provided in the cap member  30  is formed, spanned over the upper part  37  and the inner part  40 , and the narrowed portion formed in the inner hole  33 , with the cross-sectional area of the opening decreasing toward the shutter hole  41 , is formed in the inner part  40 . As a result, the toner can be filled easily in the state that there are no inner part  37  and lower part  46 . 
     In the configuration of the present embodiment, when the toner container  20  having the storage member that stores toner, and the cap member  30  integrally formed with or fixed to the storage member, and having the opening for draining the toner  41   a  formed therein, in which the opening for draining the toner  41   a  has the inner hole  33  on the storage member side, and the shutter hole  41  through which the shutter member  50  can be inserted or taken out, with the inner hole  33  and the shutter hole  41  being communicated with each other with an angle, is set in the apparatus body  1 , the shutter member  50  is shifted by the nozzle  110  provided in the apparatus body  1 . Therefore, the shutter member  50  does not go into the container, thereby providing an image forming apparatus using the toner container  20  that prevents a large amount of residual toner. 
     Fourth Embodiment 
     A fourth embodiment according to the present invention will be explained below. 
     An example of the image forming apparatus (color laser printer) according to the second embodiment is similar to that shown in  FIG. 1 . Further, the toner supply container, the toner supplying apparatus, and the setting unit are the same as those shown in  FIGS. 2 to 19 . Therefore, repeated explanation is omitted, and only a characteristic point of the fourth embodiment will be explained herein. 
     As described above, the toner passage including the inner hole  33  as a relay passage on the bag-like container  21  side, and the shutter hole  41  as the drain passage through which the shutter member can be inserted and taken out, and communicated with the inner hole  33 , is formed in the cap member  30 . The inner hole  33  is a longitudinal hole extending vertically, with the cap member  30  facing downward. On the other hand, the shutter hole  41  is a lateral hole with the axis thereof crossing the axis of the inner hole  33  substantially at right angles. The shutter hole  41  in the present embodiment is a through hole circular in cross section going through from the front surface through to the back surface of the lower body portion  40 . The inner hole  33  is a hole circular in cross section, designating the length in a minor direction inside of the bag-like container-fixing portion  32  having a boat shape as a diameter, and includes a funnel-shaped narrowed portion  33   a  formed halfway therein. That is, the inner hole  33  has a reduced diameter halfway by the narrowed portion  33   a  so that the opening area decreases toward the shutter hole  41 , and is communicated with the shutter hole  41  above thereof. Therefore, in a communicating portion between the inner hole  33  and the shutter hole  41 , the opening diameter of the inner hole  33  becomes smaller than that of the shutter hole  41 . When the cylindrical shutter member  50  is inserted in the shutter hole  41 , the opening for draining the toner is reliably closed. If the axial length of the shutter member  50  is longer than the width between the front and back surfaces of the cap member  30 , that is, the width Wb of the side, the shutter member  50  inserted into the shutter hole  41  protrudes from the cap member  30 , and obstructs the installation of the container. Therefore, it is preferable that the length of the shutter member  50  be equal to the width Wb. 
     When the cap member  30  is disassembled, after the upper part  37  is detached from the lower part  46 , a cylindrical takeout tool is inserted from a through hole  48  for disassembly formed on the lower wall of the lower part  46 , to push up the inner part  45 . As a result, the inner part  45  can be easily detached from the lower part  46 . 
     In the present embodiment, the circuit substrate  70  is fitted in the lower part  46 . The circuit substrate  70  has en electric circuit and a memory so as to confirm from the apparatus body side the installation of the toner container  20 , or the amount of the residual toner in the toner container  20 . When the toner container  20  is installed in the apparatus body, a joining terminal on the circuit substrate  70  comes in contact with a joining terminal on the apparatus body side, to transfer information between the circuit substrate  70  and the apparatus body, so as to confirm the installation of the toner container  20 , or the amount of the residual toner in the toner container  20 . 
     Recycling of the toner container  20  after the use of the toner therein has finished can be carried out in the following manner. 
     For example, by releasing the engagement between the base member (the external part  34  and the upper part  37 ) and the draining port member (the middle part  43 , the inner part  45 , and the lower part  46 ) constituting the cap member  30  of the used toner container  20 , the draining port member is detached from the base member. After detachment of the draining port member, the toner is refilled in the bag-like container  21  from the exposed opening in the base member. After having filled the toner, the base member and the draining port member are coupled by engagement thereof. By reproducing the toner container  20  in this manner, the bag-like container  21 , the base member (the external part  34  and the upper part  37 ), and the draining port member (the middle part  43 , the inner part  45 , and the lower part  46 ) can be recycled and reused. 
     After detaching the draining port member, another base member (external part  34  and upper part  37 ) fitted to the bag-like container  21  in which the new toner has been filled may be engaged with the detached draining port member. By reproducing the toner container  20  in this manner, the draining port member (the middle part  43 , the inner part  45 , and the lower part  46 ) can be recycled and reused. 
     According to the present embodiment, when the use of the toner container  20  has finished, the engagement between the base member (the external part  34  and the upper part  37 ) and the draining port member (the middle part  43 , the inner part  45 , and the lower part  46 ) constituting the cap member  30  is released. By such a simple operation of releasing the engagement between these members, the draining port member can be detached from the used toner container  20 . Therefore, a complicated operation of detaching the bonded elastic sealing material in the toner draining member, which has been required in the conventional toner container, is not necessary. Therefore, the bag-like container  21  as the bag-like powder storage, the base member, and the draining port member can be easily recycled as an individual part. Further, the opening communicating with the inside of the bag-like container  21  is exposed to the outside by the detachment of the draining port member, and the powder can be filled from the exposed opening. As a result, the bag-like container  21  can be easily recycled by refilling the toner in the bag-like container  21 . 
     According to the present embodiment, the opening area at the outlet of the inner hole  33  of the external part  34  (upper part  37 ) as the base member is larger than that of the shutter hole  41  as the powder draining portion in the middle part  43  (inner part  45 ) as the draining port member. Thus, since the opening area at the outlet of the inner hole  33  of the external part  34  (upper part  37 ) is larger than that of the shutter hole  41  in the middle part  43  (inner part  45 ), the toner can be easily filled from the outlet of the inner hole  33  of the external part  34  (upper part  37 ) exposed by detaching the middle part  43  (inner part  45 ). Further, since the opening area of the shutter hole  41  in the middle part  43  (inner part  45 ) can be kept small, leakage of the toner from the shutter hole  41  can be suppressed. 
     According to the present embodiment, the cross-sectional area of the opening of the inner hole  33  as the powder passage in the external part  34  (upper part  37 ) as the base member, in a direction of the face orthogonal to the toner passing direction decreases from the opening side of the bag-like container  211  as the powder storage toward the middle part  43  (inner part  45 ) as draining port member. Thus, since the narrowed portion  33   a  is formed such that the cross-sectional area of the opening of the inner hole  33  in the external part  34  (upper part  37 ) gradually decreases, the residual toner in the inner hole  33  can be reduced, and the toner received from the bag-like container  21  side can be allowed to pass smoothly toward the middle part  43  (inner part  45 ) side. 
     According to the present embodiment, since the shutter member  50  provided in the middle part  43  (inner part  45 ) as the draining port member moves between the position for opening the inlet of the shutter hole  41  as the drain passage on the bag-like container  21  side and the position for closing the inlet, the shutter hole  41  can be opened or closed. Therefore, leakage of the toner due to a drop in the righting moment of the elastic body, which has occurred heretofore when the conventional sealing material formed of the elastic body is used, can be prevented. 
     According to the present embodiment, since the shutter hole  41  as the drain passage is a through hole opened to the outside of the toner container  20 , the shutter member  50  is moved by inserting the nozzle for draining the toner, to automatically open the drain passage. Further, since the shutter member  50  moving in the shutter hole  41  due to the insertion of the nozzle  110  does not come into the bag-like container  21  side, it can be prevented that a large amount of toner remains in the toner container  20 . 
     According to the present embodiment, the toner passage from the bag-like container  21  to the draining port is bent at one spot or more. Therefore, when the bag-like container  21  is located above the cap member  30 , the toner in the bag-like container  21  does not move linearly toward the draining port by the gravity. Further, when the bag-like container  21  is located above the cap member  30 , since at least one part of the portion from the bent portion to the draining port of the toner passage inclines with respect to the perpendicular direction, the toner likely to move in the direction of gravity can be received by the internal wall of the inclined portion. Therefore, when the bag-like container  21  is located above the cap member  30 , leakage of the toner from the draining port can be suppressed, at the time of setting or detaching the toner container  20 . 
     Particularly, in the present embodiment, the toner passing direction near the draining port of the shutter hole  41  is inclined with respect to the toner passing direction in the inner hole  33  as the powder passage in the external part  34  (upper part  37 ) as the base member. Therefore, when the toner container  20  is detached in the state that the bag-like container  21  is located above the draining port member, the internal wall of the shutter hole  41  near the draining port inclines with respect to the perpendicular direction. Accordingly, the toner likely to move in the direction of gravity near the draining port of the shutter hole  41  can be received by the internal wall near the draining port of the shutter hole  41 , and hence toner leakage from the draining port can be further suppressed at the time of setting or detaching the toner container  20 . 
     According to the present embodiment, since the bag-like container  21  is formed of a flexible material, after the use of the toner container  20  has finished, the bag-like container  21  can be deformed so as to reduce the volume thereof. As a result, the volume of the used toner container  20  can be reduced. 
     According to the present embodiment, the opening diameter of the inner hole  33  is smaller than that of the shutter hole  41 , at the communicated portion between the inner hole  33  continuously formed over the external part  34  (the upper part  37 ) and the middle part  43  (the inner part  45 ), and the shutter hole  41  in the middle part  43  (the inner part  45 ). Therefore, the shutter member  50  inserted in the shutter hole  41  can reliably close the toner draining unit. 
     According to the present embodiment, the cap member  30  includes the upper body portion  31  and the lower body portion  40 , the upper body portion  30  is provided with the bag-like container-fixing portion  32  to which the bag-like container  21  is fixed, and the lower body portion  40  is provided with the shutter hole  41 . The lower body portion  40  is formed substantially in a rectangular parallelepiped, with the width of the front and back surfaces formed thinner than that of the opposite sides. As a result, setting of the toner container  20  to the proper position can be facilitated. 
     According to the present embodiment, since the taper, the width of which becomes narrow toward the lower part, is formed on the opposite sides of the lower body portion  40 , setting of the toner container  20  to the proper position can be facilitated. 
     According to the present embodiment, since the shutter hole  41  is a through hole going through from the front surface through to the back surface of the lower body portion  40 , the width between the front and back surfaces of the cap member  30  can be made thinner. 
     According to the present embodiment, since the width of the cap member  30  between the front and back surfaces is equal to the axial width of the shutter member  50 , there is no possibility that the shutter member  50  obstructs installation of the toner container  20 . 
     According to the present embodiment, since the sealing unit for sealing the shutter hole  41 , into which the shutter member  50  is inserted, is provided, toner leakage can be reliably prevented, and a toner supply path can be made a sealed passage. 
     According to the present embodiment, since the shutter hole  41  is circular in cross section and the sealing unit is an O-ring having resilience, provided at the end of the shutter hole, uniform sealing force can be applied over the whole circumference thereof at a reasonable cost. 
     According to the present embodiment, since the sealing unit  42  is provided in the shutter member  50 , it is not necessary to provide a seal holding unit in the cap member  30 . 
     The cap member  30  according to the present embodiment includes the middle part  43  and the external part  34 , the middle part  43  is provided with the engaging groove  44  with which the sealing unit  42  is engaged, and the external part  34  is provided with the fitting portion  35  to which the middle part  43  is fitted, the bag-like container fixing portion  32  to which the bag-like container  21  is fixed, and the holding portion  36  for holding the sealing unit  42  engaged with the engaging groove  44 . In such a configuration, the sealing unit  42  can be easily assembled, and reliably held. 
     In the cap member  30  according to the present embodiment, the shutter hole  41  is formed, spanning over the middle part  43  and the external part  34 . The cap member  30  is assembled by inserting the shutter member  50  into the shutter hole  41 , with the sealing unit  42  held by the middle part  43  and the external part  34 . As a result, a member or means for binding the middle part  43  and the external part  34  is not required. 
     In the cap member  30  according to the present embodiment, the inner hole  33  as the powder passage is formed, spanning over the middle part  43  and the external part  34 , and the narrowed portion  33   a  formed in the inner hole  33  is also formed in the middle part  43 , with the cross-sectional area of the opening decreasing toward the shutter hole  41 . As a result, by detaching the middle part  43 , the toner can be filled easily. 
     The cap member  30  according to the present embodiment includes the upper part  37 , the inner part  45 , and the lower part  46 , and the bag-like container fixing portion  32  to which the bag-like container  21  is fixed is provided in the upper part  37 . The engaging groove  46   a  with which the sealing unit  42  is engaged is provided in the inner part  45 , and the fitting portion  35  to which the inner part  45  is fitted, and the holding portion  36  for holding the sealing unit  42  engaged with the engaging groove  46   a  are provided in the lower part  46 . In such a configuration, the sealing unit  42  is easily assembled and reliably held, and when the toner container  20  is disposed, only the bag-like container  21  and the upper part  37  are disposed, and the inner part  45  and the lower part  46  can be reused. 
     The cap member  30  according to the present embodiment is provided with the coupling unit that detachably couples the upper part  37  and the lower part  46 , and the sealing unit  42  is held by fitting the inner part  45  to the fitting portion  35  in the lower part  46 . The cap member  30  is then assembled by coupling the lower part  46  that holds the sealing unit  42  by fitting of the inner part  45 , to the upper part  37  by the coupling unit. As a result, the assembly work is facilitated, and the assembly can be completed by one action after filling the toner. 
     In the cap member  30  according to the present embodiment, the coupling unit includes the fixed guide  38  provided on the lower opposite sides of the upper part  37 , and the guide support  47  provided on the upper opposite sides of the lower part  46 . The fixed guide  38  and the guide support  47  are engaged with each other by the rotation of one of the upper part  37  and the lower part  46  with respect to the other thereof. As a result, the assembly work is facilitated. 
     In the cap member  30  according to the present embodiment, the rotation of one of the upper part  37  and the lower part  46  with respect to the other thereof for allowing the engagement of the fixed guide  38  with the guide support  47  is a rotation about the axis of the inner hole. As a result, a deviation hardly occurs in the inner hole due to the coupling of the upper part  37  and the lower part  46 . 
     In the cap member  30  according to the present embodiment, the fixed guide  38  and the guide support  47  are respectively provided with the locking unit that locks the upper part  37  and the lower part  46  when these are coupled properly. As a result, the assembly accuracy is improved, thereby preventing defective assembly. 
     In the cap member  30  according to the present embodiment, the inner hole  33  as the powder passage is formed, spanned over the upper part  37  and the inner part  45 , and the narrowed portion  33   a  formed in the inner hole  33  is also formed in the inner part  45 , with the cross-sectional area of the opening decreasing toward the shutter hole  41 . As a result, the toner can be filled easily in the state that there are no inner part  45  and lower part  46 . 
     According to the present embodiment, by using the toner container  20  for the toner supplying apparatus in a color laser printer, toner leakage from the toner container  20  can be prevented, and the toner supplying apparatus and the printer, in which recycling of the toner container  20  is easy, can be configured. 
     In the embodiment, an example in which the base member constituting the cap member  30  has an inner hole  33  as the powder passage through which the toner passes is explained. However, the present invention is also applicable to an example in which the base member does not have the toner passage. For example, as shown in  FIG. 16 , the toner passage may not be formed in the external part  34  as the base member. In this configuration, the middle part  43  as the draining port member is extended up to the upper end of the external part  34 , and a toner passage communicating with the shutter hole  41  as the drain passage is formed inside the middle part  43 . 
     In the embodiment, the toner container that stores the toner as the powder is explained. However, the present invention is similarly applicable to a powder container that stores the two-component developer including the toner and the carrier, and a powder container that stores a powder of other types. 
     Therefore, according to the configuration of the embodiment, the draining port member can be detached from the used powder container by a simple operation of releasing the engagement between the base member and the draining port member constituting the powder draining member. As a result, the powder storage, the base member, and the draining port member can be easily recycled as an individual part. Further, the opening communicating with the inside of the powder storage is exposed to the outside by the detachment of the draining port member, and the powder can be filled from the exposed opening. As a result, the powder storage can be easily recycled by refilling the powder in the powder storage. 
     INDUSTRIAL APPLICABILITY 
     The image forming apparatus, the powder supplying unit, the toner container, the powder container, and the reproduction method thereof according to the present invention are useful for containers or supplying apparatus for toner or the like used for a copier, a printer, or a facsimile, and an apparatus or system using the same, and are particularly suitable for a powder container or a powder supplying unit, which stores and supplies fine powder, that is, handles a powder, and a reproduction method of the storage container.