Patent Publication Number: US-2023143399-A1

Title: Image forming system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation application of U.S. patent application Ser. No. 17/535,480, filed on Nov. 24, 2021, which is a continuation application of U.S. patent application Ser. No. 17/320,034, filed on May 13, 2021, now issued as U.S. Pat. No. 11,215,940 on Jan. 4, 2022, which claims the benefit of Japanese Patent Application No. 2020-089814 filed May 22, 2020, all of which are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     Field of the Disclosure 
     The present disclosure relates to an electrophotographic image forming system. 
     Description of the Related Art 
     There is known an electrophotographic image forming system having a configuration in which a toner container that contains toner and includes a discharge port for discharging the toner and a shutter for closing and opening the discharge port is mounted on a development unit and the toner is supplied to the development unit. Regarding this configuration, there is known a technique in which the shutter of the toner container is moved from a closed position to an open position when a user performs an operation to mount the toner container on the development unit, as discussed in Japanese Patent Application Laid-Open No. 2009-175760. 
     SUMMARY 
     According to an aspect of the present disclosure, an image forming system includes a toner container and an image forming apparatus. The toner container includes a first toner containing portion containing toner therein, a container base portion provided with a discharge port through which the toner contained in the first toner containing portion is discharged to an outside of the first toner containing portion, and a container shutter configured to be moved between an open position where the discharge port is opened and a closed position where the discharge port is closed with respect to the container base portion, the container shutter including an engaged portion. The image forming apparatus includes a main body base portion to which the toner container is detachably attached and which is provided with a receiving port for receiving the toner discharged from the discharge port of the toner container, a second toner containing portion for containing the toner received by the receiving port, a movable member configured to be moved between a first position and a second position with respect to the main body base portion, the movable member including an engaging portion configured to engage with the engaged portion of the container shutter, a regulating member configured to be moved between a regulation position for regulating a movement of the movable member from the first position to the second position and a regulation release position for releasing the regulation of the movement of the movable member, the regulating member being at the regulation position in a first state where the toner container is not attached to the main body base portion and being at the regulation release position in a second state where the toner container is attached to the main body base portion, and an urging member configured to urge the movable member to move from the first position to the second position when the regulating member is located at the regulation release position. The container shutter is configured to be moved with the movable member when the engaged portion is engaged with the engaging portion of the movable member, thereby allowing the container shutter to be at the closed position while the movable member is at the first position and to be at the open position while the movable member is at the second position. 
     Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic sectional view illustrating an image forming apparatus according to a first exemplary embodiment. 
         FIG.  2 A  is a perspective view illustrating the image forming apparatus in a state where a toner container is mounted, according to one or more exemplary embodiment. 
         FIG.  2 B  is a perspective view illustrating the image forming apparatus in a state where the toner container is not mounted, according to one or more exemplary embodiment. 
         FIG.  3    is an enlarged sectional view illustrating the toner container and a development unit, according to one or more exemplary embodiment. 
         FIG.  4 A  is a perspective view illustrating the toner container with a container shutter closed, according to one or more exemplary embodiment.  FIG.  4 B  is a perspective view illustrating the toner container viewed from a viewpoint different from that in  FIG.  4 A , according to one or more exemplary embodiment. 
         FIG.  5 A  is a perspective view illustrating the toner container with the container shutter open, according to one or more exemplary embodiment.  FIG.  5 B  is a perspective view illustrating the toner container viewed from a viewpoint different from that in  FIG.  5 A , according to one or more exemplary embodiment. 
         FIG.  6    is an exploded perspective view of the toner container, according to one or more exemplary embodiment. 
         FIG.  7 A  is a perspective view illustrating a mounting portion viewed from a toner container side, according to one or more exemplary embodiment.  FIG.  7 B  is a perspective view illustrating the mounting portion viewed from a development container side, according to one or more exemplary embodiment. 
         FIG.  8    is an exploded perspective view of the mounting portion, according to one or more exemplary embodiment. 
         FIG.  9 A  is a view illustrating a development base portion viewed from the toner container side, according to one or more exemplary embodiment.  FIG.  9 B  is a view illustrating the development base portion viewed from the development container side, according to one or more exemplary embodiment. 
         FIG.  10    is a perspective view illustrating the mounting portion in a state where a development shutter is at an open position, according to one or more exemplary embodiment. 
         FIG.  11 A  is a perspective view illustrating the toner container and the mounting portion in a state where the mounting of the toner container on the mounting portion is completed and the development shutter is about to be moved from a closed position to the open position, according to one or more exemplary embodiment.  FIG.  11 B  is a perspective view illustrating the toner container and the mounting portion in a state where the mounting of the toner container on the mounting portion is completed and the development shutter is at the open position, according to one or more exemplary embodiment. 
         FIG.  12 A  is a perspective view illustrating a state where the toner container is mounted on the mounting portion and the development shutter is at the open position, according to one or more exemplary embodiment.  FIG.  12 B  is a perspective view illustrating a state where the development shutter is at the closed position and the toner container can be detached from the mounting portion, according to one or more exemplary embodiment. 
         FIG.  13 A  is a sectional view illustrating the toner container and the mounting portion before the toner container is mounted on the mounting portion, according to one or more exemplary embodiment.  FIG.  13 B  is a sectional view illustrating the toner container and the mounting portion in a state where the toner container is mounted on the mounting portion and the container shutter and the development shutter at the closed position are about to be opened, according to one or more exemplary embodiment.  FIG.  13 C  is a sectional view illustrating the toner container and the mounting portion in a state where the toner container is mounted on the mounting portion and the development shutter is being slid from the closed position to the open position together with the container shutter, according to one or more exemplary embodiment.  FIG.  13 D  is a sectional view illustrating the toner container and the mounting portion in a state where the toner container is mounted on the mounting portion and the development shutter and the container shutter are at the open position, according to one or more exemplary embodiment. 
         FIG.  14    is a sectional view illustrating the toner container and the mounting portion in a state where the development shutter has been moved to the closed position in a state where scraped off toner is present in a shutter opening, according to one or more exemplary embodiment. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Exemplary embodiments of the present disclosure will be described below with reference to the drawings. 
       FIG.  1    is a schematic sectional view illustrating an image forming apparatus  1  according to a first exemplary embodiment.  FIG.  2 A  is a perspective view illustrating the image forming apparatus  1  in a state where a toner container  40  is mounted.  FIG.  2 B  is a perspective view illustrating the image forming apparatus  1  in a state where the toner container  40  illustrated in  FIG.  1    is not mounted. 
     [Overall Configuration] 
     The image forming apparatus  1  is a black-and-white printer that forms a toner image on a recording material P based on image information input from an external apparatus. 
     As illustrated in  FIG.  1   , the image forming apparatus  1  includes an apparatus main body  100  and a reading apparatus  200  that is openably and closably supported by the apparatus main body  100 . In addition, the toner container  40  is mounted on the image forming apparatus  1 . The image forming apparatus  1  and the toner container  40  constitute an image forming system  1000 . 
     The apparatus main body  100  roughly includes a feed unit  60 , an image forming unit  10 , a fixing unit  70 , and a discharge unit  80 . These units will be described in detail next. 
     [Image Forming Unit] 
     A configuration of the image forming unit  10  will be described.  FIG.  3    is an enlarged sectional view illustrating the toner container  40  and a part of the image forming unit  10  including a mounting portion  600 . The image forming unit  10  includes a scanner unit  11  (see  FIG.  1   ) serving as an exposure unit, a photosensitive drum  21  serving as an image carrying member, a pre-exposure unit  23 , a charge roller  22  serving as a charge member, a development unit  30 , and a transfer roller  12  (see  FIG.  1   ). The photosensitive drum  21  is a photosensitive member formed in a cylindrical shape. The photosensitive drum  21  according to the present exemplary embodiment includes a photosensitive layer formed of an organic photosensitive member with negative chargeability on a drum-like base formed of aluminum. The photosensitive drum  21  is rotationally driven at a predetermined process speed in a predetermined direction (clockwise direction viewed from  FIG.  3   ) by a motor (not illustrated). 
     The charge roller  22  makes contact with the photosensitive drum  21  with a predetermined contact pressure and forms a charging portion. A desired charging voltage is applied to the charge roller  22  by a charging high-voltage power source, so that the surface of the photosensitive drum  21  is uniformly charged to a predetermined potential. In the present exemplary embodiment, the photosensitive drum  21  is charged to a negative polarity by the charge roller  22 . 
     In order to produce a stable discharge in the charging portion, the pre-exposure unit  23  uniformly neutralizes the surface of the photosensitive drum  21  before reaching the charging portion. 
     The scanner unit  11  (see  FIG.  1   ) irradiates the photosensitive drum  21  with laser light L corresponding to image information input from an external apparatus or the reading apparatus  200  by using a polygon mirror, so that scanning exposure is performed on the surface of the photosensitive drum  21 . This exposure allows an electrostatic latent image corresponding to the image information to be formed on the surface of the photosensitive drum  21 . The scanner unit  11  is not limited to a laser scanner device. For example, a light-emitting diode (LED) exposure device including an LED array in which a plurality of LEDs is arranged in a longitudinal direction of the photosensitive drum  21  may be adopted. 
     The development unit  30  includes a development roller  31  serving as a developer carrying member that carries a developer, a development container  32  serving as the frame of the development unit  30 , and a supply roller  33  capable of supplying a developer to the development roller  31 . The development roller  31  and the supply roller  33  are rotatably supported by the development container  32 . The development roller  31  is disposed at an opening of the development container  32  so as to face the photosensitive drum  21 . The supply roller  33  is rotatably in contact with the development roller  31 , and toner serving as a developer and contained in the development container  32  is carried on the surface of the development roller  31  by the supply roller  33 . The supply roller  33  may be excluded as long as toner can be sufficiently supplied to the development roller  31 . 
     The development unit  30  according to the present exemplary embodiment uses a contact development method as a development method. More specifically, a toner layer carried on the surface of the development roller  31  makes contact with the photosensitive drum  21  in a development portion (area) where the photosensitive drum  21  and the development roller  31  face each other. A development voltage is applied to the development roller  31  by a development high-voltage power source (not illustrated). In a state where the development voltage is applied to the development roller  31 , the toner carried on the development roller  31  is transferred from the development roller  31  onto the surface of the photosensitive drum  21  based on a potential distribution on the surface of the photosensitive drum  21 , so that the electrostatic latent image is developed into a toner image. In the present exemplary embodiment, a reversal development method is adopted. More specifically, the surface of the photosensitive drum  21  is charged in a charging process and then exposed to light in an exposure process to allow toner to adhere to an area in the surface of the photosensitive drum  21  where the amount of charge has attenuated. As a result, a toner image is formed on the surface of the photosensitive drum  21 . 
     In the present exemplary embodiment, toner having a particle size of 6 μm and having a negative polarity as a normal charging polarity is used. In the present exemplary embodiment, for example, polymerized toner generated by a polymerization method is adopted. Toner used in the present exemplary embodiment is a non-magnetic one-component developer that does not contain any magnetic components and is carried on the surface of the development roller  31  mainly by an intermolecular force and an electrostatic force (image force). Alternatively, a one-component developer containing magnetic components may be used. The one-component developer may include not only toner particles, but also an additive (e.g., wax or silica microparticles) for adjusting the fluidity or charging performance of toner. Further alternatively, a two-component developer composed of non-magnetic toner and carrier having magnetic properties may be used as a developer. In the case of using a developer having magnetic properties, for example, a cylindrical development sleeve inside which a magnet is disposed is used as the developer carrying member. 
     In the development container  32 , a toner containing portion  36  serving as a second toner containing portion for containing toner, and a stirring member  34  disposed inside the toner containing portion  36  are provided. The stirring member  34  is configured to be driven and rotated by a motor (not illustrated) to stir the toner in the toner containing portion  36  and supply the toner to the development roller  31  and the supply roller  33 . In addition, the stirring member  34  functions to circulate in the development container  32  the toner that is not used in the development and is scraped off from the surface of the development roller  31 , and to make the toner in the development container  32  uniform. The stirring member  34  is not necessarily configured to be rotated. For example, a stirring member configured to swing may be adopted. 
     In the opening of the development container  32  at which the development roller  31  is disposed, a development blade  35  that regulates the amount of toner carried on the development roller  31  is disposed. The toner supplied onto the surface of the development roller  31  passes through a portion opposed to the development blade  35  along with the rotation of the development roller  31 , so that the toner is uniformly formed into a thin layer and is charged to the negative polarity by triboelectric charging. 
     The transfer roller  12  forms a transfer nip portion  99  (see  FIG.  1   ) for transferring the toner image formed on the surface of the photosensitive drum  21  onto the recording material P while making contact with the photosensitive drum  21  and conveying the recording material P. 
     [Feed Unit] 
     As illustrated in  FIG.  1   , the feed unit  60  includes a front door  61 , a tray portion  62 , a middle plate  63 , a tray spring  64 , and a pickup roller  65 . The front door  61  is openably and closably supported by the apparatus main body  100 . When the front door  61  is opened, a space for accommodating the recording material P appears. The tray portion  62  constitutes a bottom surface that forms this space. The middle plate  63  is supported by the tray portion  62  so as to be movable up and down. The tray spring  64  urges the middle plate  63  upward and presses the recording material P stacked on the middle plate  63  against the pickup roller  65 . The front door  61  encloses the space for accommodating the recording material P in a state where the front door  61  is closed with respect to the apparatus main body  100 , and supports the recording material P together with the tray portion  62  and the middle plate  63  in a state where the front door  61  is opened with respect to the apparatus main body  100 . 
     [Fixing Unit] 
     The fixing unit  70  performs a fixation process for heating and melting the toner on the recording material P to fix the toner image to the recording material P. The fixing unit  70  includes a fixing film  71 , a ceramic heater (not illustrated) for heating the fixing film  71 , a thermistor (not illustrated) for detecting the temperature of the heater, and a pressure roller  72  that is brought into pressure contact with the fixing film  71  through the heater. 
     [Image Forming Process] 
     An image forming operation performed by the image forming unit  10  of the image forming apparatus  1  will be described with reference to  FIGS.  1  and  3   . When an image forming instruction is input to the image forming apparatus  1 , the image forming process is started by the image forming unit  10  based on the image information input from an external computer or the reading apparatus  200  connected to the image forming apparatus  1 . The scanner unit  11  applies the laser light L to the photosensitive drum  21  based on the input image information. The photosensitive drum  21  has been preliminarily charged by the charge roller  22 , and thus the application of the laser light L to the photosensitive drum  21  allows an electrostatic latent image to be formed on the surface of the photosensitive drum  21 . Toner is then supplied from the development roller  31  to the photosensitive drum  21  to develop the electrostatic latent image, so that a toner image is formed on the surface of the photosensitive drum  21 . 
     In parallel with the image forming process performed by the image forming unit  10  described above, the pickup roller  65  of the feed unit  60  feeds the recording material P on the tray portion  62  to a registration roller pair  15 . The recording material P fed by the pickup roller  65  hits a nip portion of the registration roller pair  15 , so that the skew of the recording material P is corrected. The registration roller pair  15  is then driven based on the timing of when the toner image is transferred onto the recording material P at the transfer nip portion  99 , and conveys the recording material P to the transfer nip portion  99 . 
     A transfer voltage is applied to the transfer roller  12  from a transfer high-voltage power source (not illustrated), and the toner image carried on the surface of the photosensitive drum  21  is transferred onto the recording material P conveyed by the registration roller pair  15 . The recording material P to which the toner image has been transferred is conveyed to the fixing unit  70 , and the toner image is heated and pressurized while the recording material P passes through a fixing nip portion formed by the fixing film  71  and the pressure roller  72  of the fixing unit  70 . As a result, the toner particles are melted and then fixed, so that the toner image is fixed to the recording material P. The recording material P that has passed through the fixing unit  70  is discharged to the outside of the image forming apparatus  1  by the discharge unit (discharge roller pair)  80 , and is stacked on a discharge tray  81  formed at the upper portion of the apparatus main body  100  and serving as a stacking unit. 
     The discharge tray  81  is inclined upward toward the downstream side in the discharge direction of the recording material P. The recording material P discharged to the discharge tray  81  slides down the discharge tray  81 , so that the trailing edge of the recording material P is aligned by a regulating surface  84 . 
     The reading apparatus  200  includes a reading unit  201  in which a reading portion (not illustrated) is incorporated, and a pressing plate  202  that is openably and closably supported by the reading unit  201 . The top surface of the reading unit  201  is provided with a platen glass  203  through which light emitted from the reading portion passes and on which a document is placed. 
     In a case where an image on a document is read by the reading apparatus  200 , a user places the document on the platen glass  203  in a state where the pressing plate  202  is open. The user then closes the pressing plate  202  to prevent misregistration of the document on the platen glass  203 , and outputs a reading instruction to the image forming apparatus  1  by, for example, operating an operation unit  300  (see  FIGS.  2 A and  2 B ). When a reading operation is started, the reading portion in the reading unit  201  reciprocates in a sub-scanning direction, i.e., a left-right direction in a state where the operation unit  300  of the image forming apparatus  1  faces the front side. In the reading portion, light emitted from a light-emitting portion and reflected on the document is received and photoelectrically converted by a light-receiving portion, so that the image on the document is read. In the following description, the front-back direction, the left-right direction, and the up-down direction are defined based on the state where the operation unit  300  faces the front side. 
     As illustrated in  FIGS.  2 A and  2 B , a top cover  82  serving as a stacking tray is provided at the upper portion of the apparatus main body  100 , and the discharge tray  81  serving as a stacking surface is formed on the upper surface of the top cover  82 . On the top cover  82 , an opening/closing member  83  is openably and closably supported about a rotation axis  83   a  extending in the front-back direction. The discharge tray  81  of the top cover  82  is provided with an opening  82   a  that is opened upward. 
     The opening/closing member  83  is configured to move between a closed position where a supply port  32   a  (see  FIG.  7 B ) is covered to prevent the toner container  40  from being mounted on the development container  32  and an open position where the supply port  32   a  is exposed to the outside so that the toner container  40  can be mounted on the development container  32 . The opening/closing member  83  at the closed position functions as a part of the discharge tray  81 . The opening/closing member  83  and the opening  82   a  are formed on the left side of the discharge tray  81 . When the user hooks his/her finger at a groove portion  82   b  provided in the top cover  82 , the opening/closing member  83  is opened in the left direction. The opening/closing member  83  is formed substantially in an L-shape along the shape of the top cover  82 . 
     The opening  82   a  of the discharge tray  81  is opened so that the mounting portion  600  formed at the upper portion of the development container  32  is exposed to the outside. When the opening/closing member  83  is opened, the user can access the mounting portion  600  without opening the top cover  82 . In the present exemplary embodiment, a method in which the toner container  40  (see  FIGS.  1  and  3   ) is mounted on the mounting portion  600  that is a part of the development unit  30 , and toner is supplied directly to the development unit  30  (development container  32 ) is adopted. The toner container  40  is mounted on the mounting portion  600  of the image forming apparatus  1  in a state where at least a part of the toner container  40  is exposed to the outside. 
     Using the above-described configuration eliminates the need to replace the entire development unit  30  including the toner containing portion  36  (see  FIG.  3   ), thereby achieving excellent usability. In addition, there is no need to replace process components such as various types of rollers, which leads to a reduction in cost. 
     [Configuration of Toner Container] 
     The toner container  40  that is attachable to or detachable from the image forming apparatus  1  will be described next.  FIG.  4 A  is a perspective view illustrating the toner container  40  with a container shutter  41  closed.  FIG.  4 B  is a perspective view illustrating the toner container  40  viewed from a viewpoint different from that in  FIG.  4 A .  FIG.  5 A  is a perspective view illustrating the toner container  40  with the container shutter  41  open.  FIG.  5 B  is a perspective view illustrating the toner container  40  viewed from a viewpoint different from that in  FIG.  5 A .  FIG.  6    is an exploded perspective view of the toner container  40 . 
     As illustrated in  FIG.  6   , the toner container  40  includes a pouch  501 , a nozzle  502 , a container base portion  503 , a container seal  504 , a container sheet  505 , and the container shutter  41 . 
     The pouch  501  serving as a first toner containing portion is a flexible container, and is configured so that toner contained in the pouch  501  can be easily discharged to the outside of the pouch  501  when the user presses the pouch  501  from the outside or squeezes the pouch  501 . The pouch  501  is formed of a material, for example, resin such as polyethylene, polypropylene, or polyethylene terephthalate, a composite material thereof, non-woven cloth, cloth, or paper. 
     While the pouch  501  is used in the present exemplary embodiment, a bottle or a paper bag may be used. 
     The nozzle  502  includes a discharge port  502   a  for discharging the toner contained in the pouch  501 . The pouch  501  is joined to the nozzle  502  with an adhesive such as a hot-melt adhesive or by thermal welding. 
     The container base portion  503  includes an opening  503   a  in which a part of the nozzle  502  is accommodated. The discharge port  502   a  of the nozzle  502  is exposed, through the opening  503   a,  from a side of the container base portion  503  opposite to a side on which the pouch  501  is disposed. The container base portion  503  is joined to the nozzle  502  with an adhesive such as a hot-melt adhesive or by ultrasonic welding. The container base portion  503  includes claw portions  503   b  each serving as a shutter engaging portion that can be elastically displaced. In the present exemplary embodiment, the container base portion  503  and the nozzle  502  are separate components. Alternatively, the container base portion  503  may be integrally formed with the nozzle  502  and the opening  503   a  may also function as the discharge port  502   a.    
     The container shutter  41  is supported by the container base portion  503  so as to be slidable (movable) with respect to the container base portion  503 . The container shutter  41  includes groove portions  41   a  and pressing portions  41   b.  Each of the groove portion  41   a  serves as an engaged portion to be engaged with the corresponding claw portion  503   b  of the container base portion  503 . Each of the pressing portions  41   b  protrudes from a surface of the container shutter  41  opposite to a surface facing the container base portion  503 . The container shutter  41  is slidable between a closed position (first closed position) illustrated in  FIGS.  4 A and  4 B  and an open position (first open position) illustrated in  FIGS.  5 A and  5 B . At the closed position, the discharge port  502   a  of the nozzle  502  (the opening  503   a  of the container base portion  503 ) is closed. At the open position, the discharge port  502   a  is opened. 
     The claw portions  503   b  of the container base portion  503  are configured to move between an engagement position and an engagement release position with respect to the groove portions  41   a  of the container shutter  41 . At the engagement position, the claw portions  503   b  engage with the groove portions  41   a.  At the engagement release position, the engagement with the groove portions  41   a  is released. While the container shutter  41  is at the closed position, as illustrated in  FIGS.  4 A and  4 B , the claw portions  503   b  of the container base portion  503  are at the engagement position. With this configuration, the container shutter  41  cannot be accidentally moved from the closed position to the open position when the user carries only the toner container  40 , thereby preventing toner leakage. 
     The container seal  504  is formed of urethane foam, non-woven cloth, or the like, and is fixed by a fixing member, such as a double-sided adhesive tape, to an external surface of the container base portion  503  that faces the container shutter  41 . The container seal  504  includes a hole  504   a  that is equal to or larger than the opening  503   a  of the container base portion  503 . The opening  503   a  is exposed from the container seal  504  through the hole  504   a.  The hole  504   a  functions as a conveyance path through which the toner discharged from the discharge port  502   a  of the nozzle  502  passes. As illustrated in  FIG.  4 A , an end  504   b  of the container seal  504  in the direction in which the container shutter  41  is moved from the open position to the closed position sticks out from an end of the container shutter  41  at the closed position on the same side as that of the end  504   b.  The end  504   b  of the container seal  504  is exposed to the outside of the toner container  40 . 
     The container sheet  505  is fixed by a fixing member, such as a double-sided adhesive tape, to a surface  41   c  (see  FIG.  6   ) of the container shutter  41  that faces the container seal  504  fixed to the container base portion  503 . As illustrated in  FIG.  4 A , an end  505   a  of the container sheet  505  in the direction in which the container shutter  41  is moved from the open position to the closed position sticks out from the end of the container shutter  41  on the same side as that of the end  505   a,  and is exposed to the outside of the toner container  40 . 
     [Toner Container Mounting Portion] 
     The configuration of the mounting portion  600  that is a part of the development unit  30  will be described next. The mounting portion  600  is configured to detachably mount the toner container  40  thereon, and is integrally formed with the development container  32  as illustrated in  FIG.  3    in the present exemplary embodiment.  FIG.  7 A  is a perspective view illustrating the mounting portion  600  viewed from the toner container  40  side.  FIG.  7 B  is a perspective view illustrating the mounting portion  600  viewed from the development container  32  side.  FIG.  8    is an exploded perspective view of the mounting portion  600 . 
     As illustrated in  FIG.  8   , the mounting portion  600  can be divided into a development base portion (main body base portion)  506 , a development shutter (main body shutter)  507 , and a regulating member  512 . The development base portion  506  and the development shutter  507  are provided with a development base seal  508  and a development shutter seal  510 , respectively. 
     As illustrated in  FIG.  3   , the development base portion  506  is connected to the development container  32  and can be divided into an upper portion and a lower portion.  FIG.  9 A  illustrates the development base portion  506  viewed from the toner container  40  side (from above).  FIG.  9 B  illustrates the development base portion  506  viewed from the development container  32  side (from below).  FIG.  10    is a perspective view illustrating the mounting portion  600  in a state where the development shutter  507  is at an open position. 
     As illustrated in  FIGS.  7 A and  9 A , the upper portion of the development base portion  506  is provided with an insertion opening  506   a  for inserting the container shutter  41  and the container base portion  503  of the toner container  40 , and a base closing portion  506   b.    
     As illustrated in  FIGS.  7 B and  9 B , the lower portion of the development base portion  506  is provided with the supply port  32   a  that communicates with the toner containing portion  36  of the development container  32 , and through-holes  32   b.  The supply port  32   a  is a receiving port that receives the toner discharged from the discharge port  502   a  of the toner container  40  in a state where the toner container  40  is mounted on the mounting portion  600 . As illustrated in  FIG.  9 B , the supply port  32   a  is a long hole that is elongated in the direction in which the insertion opening  506   a  and the base closing portion  506   b  are arranged side by side, and overlaps both the insertion opening  506   a  and the base closing portion  506   b  when viewed from above. The direction in which the insertion opening  506   a  and the base closing portion  506   b  are arranged side by side coincides with the direction in which the development shutter  507  (described below) is slid (moved). 
     As illustrated in  FIG.  8   , the development base portion  506  further includes guide groove portions  506   c,  development base locking portions  506   d,  and a rocking shaft  506   e.    
     As illustrated in  FIG.  7 A , the development base seal  508  is fixed to the inner surface of the base closing portion  506   b  of the development base portion  506  by a fixing member such as a double-sided adhesive tape. The development base seal  508  includes a surface layer  508   a  made of a film material with a thickness of 50 to 250 μm, and an elastic layer  508   b  formed of urethane foam, non-woven cloth, or the like. An end  508   a   1  of the surface layer  508   a  in an X-direction illustrated in  FIG.  7 A  sticks out from an end of the elastic layer  508   b  on the same side. 
     The development shutter  507  includes a shutter opening  507   a  and a shutter closing portion  507   b.  The development shutter  507  is slidable (movable) in a sliding direction (X-direction or Y-direction) in an area between the upper portion of the development base portion  506  where the insertion opening  506   a  and the base closing portion  506   b  are provided and the lower portion of the development base portion  506  where the supply port  32   a  is provided. The development shutter  507  is supported by the development base portion  506  so as to be slidable between a closed position (second closed position or first position) illustrated in  FIG.  7 A  and the open position (second open position or second position) illustrated in  FIG.  10    with respect to the development base portion  506 . The X-direction illustrated in  FIGS.  7 A and  7 B  coincides with the direction in which the development shutter  507  is moved from the closed position to the open position. The Y-direction coincides with the direction in which the development shutter  507  is moved from the open position to the closed position. 
     An end of the development shutter  507  in the direction orthogonal to the sliding direction is slidably guided (supported) by the guide groove portions  506   c  (see  FIG.  8   ) located on the inside of a connecting portion that connects the upper portion and the lower portion of the development base portion  506 . 
     Next, the open position and the closed position of the development shutter  507  will be described in detail. As illustrated in  FIG.  10   , the open position of the development shutter  507  is a position where the shutter opening  507   a  overlaps the insertion opening  506   a  and the supply port  32   a  of the development base portion  506  when the development shutter  507  is viewed from above. The closed position of the development shutter  507  is a position where the shutter closing portion  507   b  overlaps the supply port  32   a  and the shutter opening  507   a  overlaps the base closing portion  506   b  and the supply port  32   a  when the development shutter  507  is viewed from above. 
     While the development shutter  507  is at the open position, the toner containing portion  36  of the development container  32  can receive the toner discharged from the discharge port  502   a  of the toner container  40  through the supply port  32   a.  While the development shutter  507  is at the closed position, the supply port  32   a  of the development base portion  506  is closed by the shutter closing portion  507   b  so as to prevent the supply port  32   a  from being exposed from the insertion opening  506   a,  thereby preventing contamination of foreign matter or the like. 
     The development shutter seal  510  is fixed to a surface of the development shutter  507  that faces the base closing portion  506   b  and the insertion opening  506   a  of the development base portion  506  by a fixing member such as a double-sided adhesive tape. The development shutter seal  510  includes an opening  510   a  provided at a position corresponding to the shutter opening  507   a.  The development shutter seal  510  is configured so that, while the development shutter  507  is at the closed position, the development shutter seal  510  is in tight contact with the development base seal  508  of the development base portion  506  to prevent toner leakage in the vicinity of the shutter opening  507   a.    
     The development shutter  507  further includes ribs  507   c  each serving as an engaging portion, shutter locking portions  507   d,  a regulated surface  507   e,  rack teeth  507   f  serving as a driving force receiving portion, a slope portion  507   h,  and through-holes  507   g.    
     [Mounting of Toner Container] 
     The mounting portion  600  has a mechanism for moving the development shutter  507  from the closed position to the open position when the toner container  40  is mounted on the mounting portion  600 . This mechanism will be described next.  FIG.  11 A  is a perspective view illustrating the toner container  40  and the mounting portion  600  in a state where the mounting of the toner container  40  on the mounting portion  600  is completed and the development shutter  507  is about to be moved from the closed position to the open position.  FIG.  11 B  is a perspective view illustrating the toner container  40  and the mounting portion  600  in a state where the mounting of the toner container  40  on the mounting portion  600  is completed and the development shutter  507  is at the open position. 
     The mounting portion  600  includes tension coil springs  511  each serving as a first urging member. One end and the other end of each of the tension coil springs  511  in an expansion/contraction direction thereof are locked with the corresponding development base locking portion  506   d  of the development base portion  506  and the corresponding shutter locking portion  507   d  of the development shutter  507 , respectively. The tension coil springs  511  urge the development shutter  507  in the direction in which the development shutter  507  is moved from the closed position to the open position with respect to the development base portion  506 . 
     The regulating member  512  is configured to be moved between a regulation position (see  FIGS.  7 A and  7 B ) where the movement of the development shutter  507  from the closed position to the open position is regulated and a regulation release position (see  FIGS.  10 ,  11 A, and  11 B ) where the regulation of the movement of the development shutter  507  from the closed position to the open position is released. In the present exemplary embodiment, as illustrated in  FIG.  8   , the regulating member  512  includes rockably supported portions  512   a  that are rockably supported by the rocking shaft  506   e  of the development base portion  506 , and is moved up and down around the rockably supported portions  512   a  between the regulation position and the regulation release position. 
     A regulating surface  512   d  of the regulating member  512  is in contact with the regulated surface  507   e  of the development shutter  507  while the regulating member  512  is at the regulation position as illustrated in  FIGS.  7 A and  7 B , thereby regulating the movement of the development shutter  507  from the closed position to the open position. The regulated surface  507   e  is an end surface of the development shutter  507  in the direction in which the development shutter  507  is moved from the closed position to the open position. While the regulating member  512  is at the regulation release position as illustrated in  FIG.  10   , the regulating surface  512   d  of the regulating member  512  is retracted to avoid contact with the regulated surface  507   e  of the development shutter  507 , thereby allowing the development shutter  507  to move from the closed position to the open position. The development shutter  507  is moved from the closed position to the open position by the force of the tension coil springs  511  when the regulating member  512  is located at the regulation release position. 
     The regulating member  512  is configured to be moved from the regulation position to the regulation release position when the toner container  40  is mounted on the mounting portion  600 . More specifically, the regulating member  512  is at the regulation position in a state (first state) where the toner container  40  is not mounted on the mounting portion  600 , and is at the regulation release position in a state (second state) where the mounting of the toner container  40  on the mounting portion  600  is completed. 
     As illustrated in  FIGS.  11 A and  11 B , the mounting portion  600  includes a compression coil spring  513  serving as a second urging member. On end of the compression coil spring  513  in a compression direction thereof is supported by a spring support portion  512   b  of the regulating member  512 . The other end of the compression coil spring  513  is supported by a spring support portion  700  provided at a portion of the mounting portion  600  not to be moved with the regulating member  512  or the development shutter  507 . The compression coil spring  513  is compressed between the spring support portion  512   b  and the spring support portion  700  and urges the regulating member  512  in the direction in which the regulating member  512  is rocked (moved) from the regulation release position to the regulation position. 
     In a state where the toner container  40  is not mounted on the mounting portion  600 , as illustrated in  FIG.  7 A , the regulating member  512  is located at the regulation position by the urging force of the compression coil spring  513 . Accordingly, the development shutter  507  is regulated by the regulating member  512  and remains at the closed position. While the toner container  40  is being mounted on the mounting portion  600 , the pressing portions  41   b  (see  FIG.  4 A ) of the container shutter  41  press pressed portions  512   c  (see  FIG.  7 A ) of the regulating member  512  that are exposed from the through-holes  507   g  of the development shutter  507 , and press down the regulating member  512 . Accordingly, the regulating member  512  is rocked (moved) from the regulation position to the regulation release position against the urging force of the compression coil spring  513 , and the development shutter  507  is slid (moved) from the closed position to the open position by the urging force of the tension coil springs  511 . The pressed portions  512   c  of the regulating member  512  illustrated in  FIG.  8    are projecting portions that protrude toward the development shutter  507  (development base portion  506 ). While the regulating member  512  is at the regulation position, the pressed portions  512   c  penetrate the through-holes  32   b  of the development base portion  506  and are exposed from the through-holes  507   g  of the development shutter  507 . 
     Next, the development shutter  507  functioning as a movable member that moves the container shutter  41  of the toner container  40  between the closed position and the open position in a state where the toner container  40  is mounted on the mounting portion  600  will be described. As illustrated in  FIG.  7 A , the development shutter  507  includes the ribs  507   c  each exposed from the insertion opening  506   a  of the development base portion  506  and serving as an engaging portion. When the front end of the toner container  40  is inserted into the insertion opening  506   a  of the mounting portion  600 , the ribs  507   c  make contact with the claw portions  503   b  of the container base portion  503  that engage with the groove portions  41   a  of the container shutter  41 , thereby causing the claw portions  503   b  to retract from the groove portions  41   a.  As illustrated in  FIG.  11 B , the ribs  507   c  engage with the groove portions  41   a  of the container shutter  41  in which space is made after the retraction of the claw portions  503   b  of the container base portion  503 . Thus, the engagement between the claw portions  503   b  of the container base portion  503  and the groove portions  41   a  is released, thereby allowing the container shutter  41  to move with respect to the container base portion  503  and move with the development shutter  507 . When the development shutter  507  is moved from the closed position (second closed position) to the open position (second open position), the development shutter  507  moves the container shutter  41  from the closed position (first closed position) to the open position (first open position). In addition, when the development shutter  507  is moved from the open position (second open position) to the closed position (second closed position), the development shutter  507  moves the container shutter  41  from the open position (first open position) to the closed position (first closed position). 
     [Operation force for Mounting Toner Container on Mounting Portion] 
     An operation force required for the user to mount the toner container  40  on the mounting portion  600  and open the development shutter  507  and the container shutter  41  is equal to a force required to move the regulating member  512  from the regulation position to the regulation release position. In this case, a frictional force generated between the rockably supported portions  512   a  of the regulating member  512  and the rocking shaft  506   e  of the development base portion  506  is referred to as a first frictional force, and a frictional force generated between the regulating surface  512   d  of the regulating member  512  and the regulated surface  507   e  of the development shutter  507  is referred to as a second frictional force. The required operation force is obtained by subtracting the weight of the toner container  40  from the sum of the urging force of the compression coil spring  513 , the first frictional force, and the second frictional force. Accordingly, when the toner container  40  is mounted on the mounting portion  600 , the operation force required for the user can be reduced as compared with a configuration in which the development shutter  507  and the container shutter  41  are manually opened. 
     In addition, in the present exemplary embodiment, when the toner container  40  is mounted on the mounting portion  600 , there is no need to manually rotate or slide the toner container  40  in order to open the development shutter  507  and the container shutter  41 . Accordingly, it is possible to prevent the pouch  501  of the toner container  40  from being squeezed and largely deformed. 
     Furthermore, in the present exemplary embodiment, the development shutter  507  and the container shutter  41  are opened by a single operation of moving the toner container  40  downward to mount the toner container  40  on the mounting portion  600 , thereby achieving excellent operability. 
     [Configuration for Detaching Toner Container from Mounting Portion] 
     A configuration and operation for detaching the toner container  40  from the mounting portion  600  will be described next.  FIG.  12 A  is a perspective view illustrating a state where the toner container  40  is mounted on the mounting portion  600  and the development shutter  507  is at the open position where toner can be supplied.  FIG.  12 B  is a perspective view illustrating a state where the development shutter  507  is at the closed position and the toner container  40  can be detached from the mounting portion  600 . 
     The mounting portion  600  includes an operation lever  516  operated by the user to slide (move) the development shutter  507  from the open position to the closed position, and a first gear  515  and a second gear  514  each serving as a driving force transmission member. 
     When the operation lever  516  in the state illustrated in  FIG.  12 A  is operated to move in a Z-direction, the development shutter  507  is slid in the Y-direction together with the container shutter  41 , so that the toner container  40  illustrated in  FIG.  12 B  can be detached from the mounting portion  600 . 
     A mechanism for moving the development shutter  507  in conjunction with the movement of the operation lever  516  will now be described. The operation lever  516  includes rack teeth  516   a  serving as a driving force transmission portion. When the operation lever  516  is moved in the Z-direction, the first gear  515  that meshes (engages) with the rack teeth  516   a  is rotationally driven, and the second gear  514  that meshes with the first gear  515  is rotationally driven. Then, the rack teeth  507   f  of the development shutter  507  that mesh with the second gear  514  receive a driving force from the second gear  514 , so that the development shutter  507  is moved in the Y-direction and reaches the closed position. When the development shutter  507  is moved in the Y-direction, the tension coil springs  511  are pulled and thus charged with a spring force. When the development shutter  507  reaches the closed position, the regulating member  512  is rocked from the regulation release position to the regulation position by the urging force of the compression coil spring  513 , and the pressed portions  512   c  press the pressing portions  41   b  of the container shutter  41  to push the toner container  40  upward (see  FIG.  7 A ). The movement of the development shutter  507  is regulated by the regulating member  512  located at the regulation position, and the development shutter  507  remains at the closed position. In this way, the toner container  40  can be detached from the mounting portion  600 . 
     [Toner Leakage Prevention Structure] 
     A toner leakage prevention structure will be described with reference to  FIGS.  13 A to  13 D  that illustrate a change of state from when the toner container  40  is mounted on the mounting portion  600  to when the container shutter  41  of the toner container  40  and the development shutter  507  are opened. 
       FIG.  13 A  is a sectional view illustrating the toner container  40  and the mounting portion  600  before the toner container  40  is mounted on the mounting portion  600 . Assuming that the width of the container shutter  41  in the sliding direction thereof is represented by d 1 , the width of the container sheet  505  is represented by d 2 , and the width of the container seal  504  is represented by d 3 , the relation of d 1 &lt;d 2 &lt;d 3  is satisfied. The end  504   b  of the container seal  504  and the end  505   a  of the container sheet  505  are exposed to the outside of the toner container  40 . 
       FIG.  13 B  is a sectional view illustrating the toner container  40  and the mounting portion  600  in a state where the toner container  40  is mounted on the mounting portion  600  and the container shutter  41  and the development shutter  507  at the closed position are about to be opened. 
     In this state, a gap δ 1  is generated between the development base seal  508  and the container seal  504  due to design variations. To address this, a configuration is provided so that the end  504   b  of the container seal  504  overlaps and is in contact (tight contact) with the front end  508   a   1  of the surface layer  508   a  of the development base seal  508  when viewed along the mounting direction of the toner container  40 . Accordingly, the gap δ 1  is sealed from the outside of the toner container  40  and the mounting portion  600 . 
     In addition, a gap δ 2  is generated between the container shutter  41  and the development shutter  507  due to design variations. To address this, a configuration is provided so that, when the end  505   a  of the container sheet  505  is viewed along the mounting direction of the toner container  40 , the end  505   a  overlaps the slope portion  507   h  at an end of the development shutter  507  in the direction from the closed position to the open position. Accordingly, the gap δ 2  is sealed from the outside of the toner container  40  and the mounting portion  600 . 
       FIG.  13 C  is a sectional view illustrating the toner container  40  and the mounting portion  600  in a state where the toner container  40  is mounted on the mounting portion  600  and the development shutter  507  is being slid from the closed position to the open position together with the container shutter  41 . In this state, the opening  503   a  of the container base portion  503  communicates with the supply port  32   a  of the development base portion  506  through the shutter opening  507   a  of the development shutter  507 , and toner is supplied to the development container  32  through a path indicated by an arrow W. As described above, since the gaps δ 1  and δ 2  are sealed, the entry of toner into the gaps δ 1  and δ 2  is prevented. Therefore, it is possible to prevent leakage of toner to the outside. 
       FIG.  13 D  is a sectional view illustrating the toner container  40  and the mounting portion  600  in a state where the toner container  40  is mounted on the mounting portion  600  and the development shutter  507  and the container shutter  41  are at the open position. The opening  503   a  of the container base portion  503  entirely overlaps the shutter opening  507   a  of the development shutter  507  when viewed along the mounting direction of the toner container  40 . In this state, the user squeezes the pouch  501  of the toner container  40  with fingers or the like to supply the toner from the pouch  501  to the development container  32 . The container seal  504  seals the periphery of the shutter opening  507   a  of the development shutter  507 , thereby preventing toner leakage. 
     [Countermeasure against Scraped Off Toner] 
     In the image forming apparatus  1 , a remaining amount detection unit (not illustrated) detects a toner full state well in advance, for example, in a state where at least the amount of toner corresponding to one toner container  40  can be supplied to the toner containing portion  36  (see  FIG.  3   ) of the development container  32 . Furthermore, the image forming apparatus  1  is configured not to issue a toner supply request in a state where the toner full state is detected. However, if the user has supplied toner although the toner supply request has not been issued, the toner accumulated in the development container  32  may overflow and reach the shutter opening  507   a  of the development shutter  507 . In this case, if the development shutter  507  is moved from the open position to the closed position, the toner that clogs in the shutter opening  507   a  is scraped off from the toner accumulated in the development container  32  and is moved with the development shutter  507 . The toner that clogs in the shutter opening  507   a  and is moved with the development shutter  507  is hereinafter referred to as scraped off toner. 
       FIG.  14    is a sectional view illustrating the toner container  40  and the mounting portion  600  immediately after the development shutter  507  is moved to the closed position in a state where scraped off toner T is present in the shutter opening  507   a.  As described above, the supply port  32   a  of the development base portion  506  is a long hole extending to a portion immediately below the shutter opening  507   a  of the development shutter  507  located at the closed position. The area of the shutter opening  507   a  having a width W 2  is included in the area of the supply port  32   a  having a width W 1 . With this configuration, if the scraped off toner T that clogs in the shutter opening  507   a  is moved to the closed position, the scraped off toner T drops down toward the supply port  32   a  in a direction indicated by an arrow illustrated in  FIG.  14   , and thus is less likely to remain in the shutter opening  507   a.  As a result, scattering and leakage of toner due to the movement of the development shutter  507  can be prevented. 
     In addition, as illustrated in  FIG.  14   , a wall portion  32   a   1  that constitutes the supply port  32   a  is inclined. The wall portion  32   a   1  is gradually inclined downward in a direction from the supply port  32   a  to the stirring member  34  (see  FIG.  3   ) of the toner containing portion  36  in the sliding direction of the development shutter  507 . Thus, the toner supplied from the supply port  32   a  is moved along the wall portion  32   a   1  and drops down at a position near the stirring member  34 . 
     In the present exemplary embodiment, the mounting portion  600  is configured as a part of the development unit  30 . However, the configuration of the mounting portion  600  is not limited thereto. In a configuration in which toner is supplied from the toner container  40  to a toner hopper that is located at a position away from the development unit  30  and contains toner to be conveyed to the development unit  30 , a mounting portion provided in the image forming apparatus  1  to mount the toner container  40  may be used. 
     In the present exemplary embodiment, the development shutter  507  that is movable so as to open or close the supply port  32   a  of the development base portion  506  is provided. However, the development shutter  507  is not limited to this configuration. Instead of using a shutter configured to move so as to open or close the supply port  32   a,  a cap that can be attached or detached by the user may be used. In this case, the development shutter  507  according to the present exemplary embodiment functions as a movable member for moving the container shutter  41  of the toner container  40 . 
     While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.