Patent Publication Number: US-11640126-B2

Title: Image forming apparatus

Description:
INCORPORATION BY REFERENCE 
     This application is based on and claims the benefit of priority from Japanese patent application No. 2021-125641 filed on Jul. 30, 2021, which is incorporated by reference in its entirety. 
     BACKGROUND 
     The present disclosure relates to an image forming apparatus provided with a detachable toner container. 
     In an image forming apparatus provided with a detachable toner container, a cover member turnable between an opened position for opening an attachment part of the toner container and a closed position for closing the attachment part is sometimes provided, and the opening/closing state of a shutter member of the toner container can be switched with the opening/closing operation of the cover member. 
     The image forming apparatus includes a rack gear which moves with the opening/closing operation of the cover member, and a gear which rotates in mesh with the rack gear and engages with the shutter member when the toner container is attached to the attachment part. When the cover member is opened, the rack gear moves in one direction to switch the shutter member to a closed state through the gear. On the other hand, when the cover member is closed, the rack gear moves in a direction opposite to one direction to switch the shutter member to an opened state through the gear. 
     In the image forming apparatus described above, when the toner container is attached to the attachment part while the cover member is rotated to the normal opened position, the shutter member is engaged with the gear. However, the toner container may be attached to the attachment part even when the cover member is not turned to the normal opened position, such as when the cover member is half-opened. Then, the shutter member is not engaged with the gear, and even when the cover member is turned to the closed position, the shutter member cannot be switched to the opened position, and the toner cannot be supplied from the toner container. Further, since the position of the toner container attached to the attachment part does not change between the state in which the cover member is not turned to the normal opened position and the state in which the cover member is turned to the normal opening position, it is impossible to visually confirm whether the toner container is normally attached. 
     SUMMARY 
     In accordance with one aspect of the present disclosure, an image forming apparatus includes a toner container, a storage part, a cover and an opening/closing mechanism. The toner container includes a shutter which is rotated to open and close a supply port for a toner. To the storage part, the toner container is detachably attached along a predetermined direction. The cover is movable between a closed position for closing the storage part and an opened position for opening the storage part. The opening/closing mechanism is configured to close the supply port by rotating the shutter in one direction in accordance with an opening operation for moving the cover to the opened position and to open the supply port by rotating the shutter in the other direction in accordance with a closing operation for moving the cover to the closed position, in a state where the toner container is attached to the storage part. The toner container includes an interference portion which interferes with the opening/closing mechanism to prevent the toner container from being attached to the storage part in a case where the cover is not moved to the opened position normally. 
     The above and other objects, features, and advantages of the present disclosure will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present disclosure is shown by way of illustrative example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a front view schematically showing an inner structure of an image forming apparatus according to one embodiment of the present disclosure. 
         FIG.  2    is a view showing a toner container of the image forming apparatus according to the embodiment of the present disclosure, when viewed from the rear side. 
         FIG.  3    is a front view showing a container storage part (in a state where a discharge tray is turned to a closed position) of the image forming apparatus according to the embodiment of the present disclosure. 
         FIG.  4    is a front view showing the container storage part (in a state where the discharge tray is turned to an opened position) of the image forming apparatus according to the embodiment of the present disclosure. 
         FIG.  5    is a front view showing an opening/closing gear in the image forming apparatus according to the embodiment of the present disclosure. 
         FIG.  6 A  is a view showing a link member coupling the opening/closing gear to a body side coupling (in the state where the discharge tray is turned to the opened position) in the image forming apparatus according to the embodiment of the present disclosure. 
         FIG.  6 B  is a view showing the link member coupling the opening/closing gear to the body side coupling (in the state where the discharge tray is turned to the closed position) in the image forming apparatus according to the embodiment of the present disclosure. 
         FIG.  7    is a view showing the toner container in a middle of attaching to the container storage part, in the image forming apparatus according to the embodiment of the present disclosure. 
         FIG.  8 A  is a view showing a state where an engagement protrusion of the toner container is engaged with an engagement protrusion of the opening/closing gear, in the image forming apparatus according to the embodiment of the present disclosure. 
         FIG.  8 B  is a view showing a state where a skitter of the toner container is turned to an opened position, in the image forming apparatus according to the embodiment of the present disclosure. 
         FIG.  9 A  is a view showing the toner container and the opening/closing gear in a state where the discharge tray is not turned to the closed position fully, in the image forming apparatus according to the embodiment of the present disclosure. 
         FIG.  9 B  is a view showing the toner container and the opening/closing gear in a state where the discharge tray is not turned to the opened position fully, in the image forming apparatus according to the embodiment of the present disclosure. 
         FIG.  10    is a view showing the toner container and the opening/closing gear in a state where the discharge tray is not turned to the opening state fully, in a case where the shutter is not provided with an interference protrusion. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, with reference to the drawings, an image forming apparatus according to one embodiment of the present disclosure will be described. 
     With reference to  FIG.  1   , the image forming apparatus  1  will be described.  FIG.  1    is a front view schematically showing an inner structure of the image forming apparatus  1 . Reference numerals L and R in each drawing indicate the left and right sides of the image forming apparatus  1 , respectively. 
     The image forming apparatus  1  includes a housing  3  having a substantially rectangular parallelepiped hollow space. In the hollow space of the housing  3 , a sheet feeding part  5 , an electrophotographic type image forming part  7 , a fixing device  9 , and a discharge device  11  are stored. Further, in the hollow space of the housing  3 , a main conveyance path  13  along which a sheet is conveyed from the sheet feeding part  5  to the discharge device  11  via the image forming part  7  and the fixing device  9  is provided. 
     The top plate of the housing  3  is provided with a sheet discharge port  15  and a sheet discharge tray  17 . The discharge tray  17  is supported in a turnable manner around a turning shaft  19  provided below the discharge port  15 . The hollow space of the housing  3  is opened by turning the discharge tray  17  upward. 
     The sheet feeding part  5  is disposed in the lower portion of the hollow space, and includes a sheet feeding cassette  21  in which the sheet is stored, and a sheet feeding device  23  which feeds the sheet from the sheet feeding cassette  21  to the main conveyance path  13 . 
     The image forming part  7  is disposed above the sheet feeding part  5 , and includes an endless intermediate transfer belt  27 , four image carrier units  29  and four developing units  31  corresponding to toners of four colors (yellow, magenta, cyan and black), four primary transfer rollers  33  corresponding to the four image carrier units  29 , a secondary transfer roller  35 , and an exposure device  37 . 
     The intermediate transfer belt  27  is wound around a driving roller and a driven roller which are disposed apart from each other in the left-and-right direction. As the driving roller rotates, the intermediate transfer belt  27  travels in the counterclockwise direction of  FIG.  1   . 
     The four image carrier units  29  are disposed side by side along the traveling direction of the intermediate transfer belt  27  so as to face the lower track of the intermediate transfer belt  27 . Each of the four developing units  31  is disposed on the upstream side of corresponding image carrier unit  29  in the traveling direction of the intermediate transfer belt  27 . The four primary transfer rollers  33  are disposed in the hollow space of the intermediate transfer belt  27 , and face the four image carrier units  29  across the intermediate transfer belt  27 . The secondary transfer roller  35  is disposed facing the intermediate transfer belt  27  on the downstream side of the four image carrier units  29  and the four developing units  31  in the traveling direction of the intermediate transfer belt  27 . A transfer nip  39  is formed between the secondary transfer roller  35  and the intermediate transfer belt  27 . 
     The exposure device  37  is disposed below the four image carrier units  29  and the four developing units  31 , and exposes the four image carrier units  29  based on image data. 
     Each of the four developing units  31  is connected to a toner container  41  containing the toner of corresponding color. The four toner containers  41  are stored in a container storage part  43  provided in the housing  3 . The container storage part  43  is provided above the intermediate transfer belt  27  and below the discharge tray  17 . The container storage part  43  is opened by turning the discharge tray  17  upward. The toner container  41  is detachably attached to the container storage part  43  along the attaching/detaching direction along the upper-and-lower direction. As described above, the discharge tray  17  is an example of a cover which opens and closes the container storage part  43 . When the toner container  41  is attached to the container storage part  43 , the toner container  41  can communicate with the corresponding developing unit  31 . The toner container  41  and the container storage part  43  will be described later. 
     The fixing device  9  is disposed above the transfer nip  39 , and includes a pressing roller and a heating roller, and a fixing nip  47  is formed between both rollers. The discharge device  11  is disposed above the fixing device  9  and inside the discharge port  15 . 
     The main conveyance path  13  is formed from the sheet feeding device  23  of the sheet feeding part  5  to the discharge device  11  through the transfer nip  39  and the fixing nip  47 . On the main conveyance path  13 , a registration rollers pair  49  is disposed between the sheet feeding device  23  and the transfer nip  39 . 
     Next, the image forming operation will be briefly described. In the image forming part  7 , the image carrier units  29  form electrostatic latent images corresponding to the image data by the exposing by the exposure device  37 . The developing units  31  develop the electrostatic latent images formed on the image carrier units  29  into toner images. The toner image of each image carrier unit  29  is transferred to the intermediate transfer belt  27  by the corresponding primary transfer roller  33 . 
     On the other hand, in the sheet feeding part  5 , the sheet is conveyed from the sheet feeding cassette  21  to the main conveyance path  13  by the sheet feeding device  23 . The sheet is conveyed to the transfer nip  39  by the registration rollers pair  49  at appropriate timing. At the transfer nip  39 , the toner images formed on the intermediate transfer belt  27  are transferred to the sheet. The sheet is conveyed to the fixing device  9  along the main conveyance path  13 , and the toner image is fixed to the sheet at the fixing nip  47 . The sheet is further conveyed to the discharge device  11 , and is discharged to the discharge tray  17  through the discharge port  15  by the discharge device  11 . 
     Next, the toner container  41  will be described with reference to  FIG.  2   .  FIG.  2    is a view showing the toner container  41  viewed from the rear side. 
     The toner container  41  includes a substantially rectangular parallelepiped housing  51  having a hollow space long in the front-and-rear direction, and a supply screw  53  and an agitating paddle  55  which are housed in the housing  51 . The rear side plate of the housing  51  is formed with a recess  51   a  recessed inward along a direction (the left-and-right direction) intersecting the attaching/detaching direction (the upper-and-lower direction). 
     The housing  51  has a cylindrical duct  51   b  protruding rearward from the lower portion of the rear side plate. On the lower surface of the duct  51   b , a supply port (not shown) through which the toner is supplied to the developing unit  31  is formed. A cylindrical shutter  57  is rotatably supported around the duct  51   b . A communication port (not shown) is formed in the shutter  57  along the circumferential direction. By rotating the shutter  57  to communicate the communication port with the supply port of the duct  51   b , the toner can be supplied to the developing unit  31  through the supply port and the communication port. 
     On the outer circumferential surface of the shutter  57 , an engagement protrusion  61  and an interference protrusion  63  are formed at an interval in the circumferential direction. As an example, the engagement protrusion  61  and the interference protrusion  63  are spaced apart at a center angle of about 70 degrees with respect to the center of the shutter  57 . The engagement protrusion  61  has a rectangular cylindrical shape long in the circumferential direction of the shutter  57  when viewed from the rear side. The engagement protrusion  61  has a slit  61   a  formed along the axial direction of the shutter  57 . The interference protrusion  63  has a substantially trapezoidal cylindrical shape long in the circumferential direction of the shutter  57  when viewed from the rear side, and has two leg portions  63   a  along the radial direction of the shutter  57  and an outer circumferential portion  63   b  connecting the two leg portions  63   a . The length of the leg portion  63   a  on the side close to the engagement protrusion  61  is longer than the length of the other leg portion  63   a.    
     The engagement protrusion  61  is disposed at a position different from the communication port in the circumferential direction. As an example, the engagement protrusion  61  and the communication port are spaced apart at a center angle of about 90 degrees with respect to the center of the shutter  57 . Therefore, as shown in  FIG.  2   , when the shutter  57  is rotated so that the engagement protrusion  61  protrudes directly downward, the communication port of the shutter  57  does not communicate with the supply port of the duct  51   b , and the toner is not supplied. The posture of the shutter  57  at this time (see the solid line in  FIG.  2   ) is referred to as a closed posture. 
     When the shutter  57  is rotated in the closed posture, the interference protrusion  63  protrudes outward (rearward) from the duct  51   b , and the outer circumferential portion  63   b  extends along the upper-and-lower direction. On the other hand, when the shutter  57  rotated in the closed posture is rotated by about 90 degrees in the clockwise direction of  FIG.  2   , the communication port of the shutter  57  communicates with the supply port of the duct  51   b , so that the toner can be supplied. The posture of the shutter  57  at this time (refer to the two-dot chain line in  FIG.  2   ) is referred to as an opened posture. When the shutter  57  rotates in the opened posture, the interference protrusion  63  protrudes upward from the duct  51   b . As described above, the interference protrusion  63  is disposed on the downstream of the engagement protrusion  61  in the rotating direction of the shutter  57  from the closed posture to the opened posture. 
     The front end of the supply screw  53  is rotatably supported by the front side plate of the housing  51 , and the rear end protrudes rearward from the rear side plate of the duct  51   b . A first gear  71  is fixed to the rear end of the supply screw  53  protruding from the rear side plate of the duct  51   b.    
     The agitating paddle  55  is disposed above the supply screw  53 . The front end of the agitating paddle  55  is rotatably supported by the front side plate of the housing  51 , and the rear end protrudes rearward from the rear side plate of the housing  51 . A second gear  73  is fixed to the rear end of the agitating paddle  55  protruding from the rear side plate of the housing  51 . On the rear side surface of the second gear  73 , a container side coupling  75  is fixed coaxially with the supply screw  53 . The container side coupling  75  has three coupling pieces disposed at predetermined intervals along the rotating direction of the agitating paddle  55 . 
     The first gear  71  and the second gear  73  are connected through an idle gear  77 . When the second gear  73  is rotated, the agitating paddle  55  is rotated to agitate the toner in the housing  51 . When the second gear  73  is rotated, the first gear  71  is rotated through the idle gear  77  to rotate the supply screw  53 . As a result, the toner in the housing  51  is conveyed toward the supply port. 
     Next, the container storage part  43  will be described with reference to  FIG.  3    and  FIG.  4   .  FIG.  3    and  FIG.  4    are front views showing the rear container storage part  43 . 
     As described above, the container storage part  43  is provided in the front side plate and the rear side plate of the housing  3  above the intermediate transfer belt  27  (see  FIG.  1   ). In each of the front side plate and the rear side plate of the housing  3 , five guide protrusions  81  and a stepped portion  83  are provided. The five guide protrusions  81  are formed along the upper-and-lower direction, and disposed at intervals in the left-and-right direction. The stepped portion  83  extends along the left-and-right direction below the guide protrusions  81 . The front stepped portion  83  is formed to protrude into the hollow space of the housing  3  by recessing the front side plate toward the rear side, and the rear stepped portion  83  is formed to protrude into the hollow space of the housing  3  by recessing the rear side plate toward the front side. The stepped portion  83  below the two adjacent guide protrusions  81  are formed to correspond to the shape of the bottom portion of the housing  51  of the toner container  41 . 
     Four individual storage parts for storing the four toner containers  41  are formed side by side in the left-and-right direction by the two adjacent guide protrusions  81  and the stepped portion  83  below the two guide protrusions  81 . In one guide protrusion  81  of each individual storage part, a lock member  85  which positions the toner container  41  is supported in a movable manner along the left-and-right direction intersecting the attaching/detaching direction (the upper-and-lower direction). Each lock member  85  is biased by a spring in a direction protruding to the individual storage part. 
     The toner container is guided in the attaching/detaching direction by the guide protrusions  81  adjacently disposed in the left-and-right direction, and the front and rear ends of the housing  51  are placed on the front and rear stepped portions  83 , so that the toner container  41  is attached to the individual storage part. When the toner container  41  is attached to the individual storage part, the lock member  85  of the guide protrusion  81  is engaged with the recess  51   a  (see  FIG.  2   ) of the toner container  41 , and the toner container  41  is positioned in the corresponding individual storage part. 
     In each of the individual storage parts, the rear side plate has a support shaft  87  protruding above the stepped portion  83  and a circular opening  89  formed above the support shaft  87 . An opening/closing gear  91  is supported on the support shaft  87 . A drive side coupling  115  is supported in the opening  89 . 
     First, the opening/closing gear  91  will be described with reference to  FIG.  5   .  FIG.  5    is a view showing the opening/closing gear  91  when viewed from the front side. The opening/closing gear  91  is a substantially fan-shaped member when viewed from the front side, and has a flat plate portion  93 , a gear portion  95  and an engagement protrusion  97  which are provided on the flat plate portion  93 . 
     The flat plate portion  93  has a substantially fan-shaped shape when viewed from the front side. A shaft hole  101  through which the support shaft  87  is inserted is formed in the vicinity of the center of the substantially fan-shape. Further, a substantially rectangular opening  103  is formed in the flat plate portion  93  on one end side in the circumferential direction. Around the outer circumference of the flat plate portion  93 , an outer circumferential wall  93   a  is formed along the circumferential direction around the shaft hole  101 . 
     The gear portion  95  is formed around the outer circumferential surface of the outer circumferential wall  93   a  of the flat plate portion  93 . As an example, the gear portion  95  is formed within a range of a center angle of about 90 degrees around the shaft hole  101 . The engagement protrusion  97  is formed on the inner circumferential surface of the outer circumferential wall  93   a  of the flat plate portion  93 . The engagement protrusion  97  is formed on the side opposite to the opening  103  in the circumferential direction. The engagement protrusion  97  has an engagement piece  111  and a pair of guide pieces  113  disposed on both sides of the engagement piece  111  in the circumferential direction. The engagement piece  111  is formed linearly along the radial direction of the shaft hole  101 . Each of the guide pieces  113  has a substantially trapezoidal cylindrical shape long in the circumferential direction when viewed from the front side, and has a length (height) along the radial direction longer than that of the engagement piece  111 . Each guide piece  113  has two leg portions  113   a  and an outer circumferential portion  113   b  connecting the two leg portions  113   a . The leg portions  113   a  on the side closer to the engagement piece  111  are formed in parallel with the engagement piece  111 , and the leg portions  113   a  on the side farther from the engagement piece  111  are formed along the radial direction. 
     As shown in  FIG.  3    and  FIG.  4   , the opening/closing gear  91  is rotatably supported by the support shaft  87  protruding from the rear side plate, and rotates in accordance with the opening/closing operation of the discharge tray  17 . 
     A drive gear  121  is provided around the turning shaft  19  of the discharge tray  17 . The drive gear  121  is a fan-shaped gear, and rotates around the turning shaft  19  together with the turning shaft  19 . That is, the drive gear  121  rotates in accordance with the opening/closing operation of the discharge tray  17 . 
     A rack gear  123  is supported below the stepped portion  83  of the rear side plate so as to be movable along the horizontal direction. One end of the rack gear  123  is meshed with the drive gear  121 . The rack gear  123  is meshed with the gear portion  95  (see  FIG.  5   ) of the opening/closing gear  91  supported by each individual storage part through a slit (not shown) formed on the bottom portion of the stepped portion  83 . Thus, when the drive gear  121  is rotated in accordance with the opening/closing operation of the discharge tray  17 , the rack gear  123  is moved along the horizontal direction, and the opening/closing gears  91  are rotated. 
     More specifically, as shown in  FIG.  3   , when the discharge tray  17  is turned to the opened position, the rack gear  123  is moved to the leftmost position, and the opening/closing gear  91  is rotated so that the engagement piece  111  of the engagement protrusion  97  faces downward. The posture of the opening/closing gear  91  at this time is referred to as an initial posture. When the discharge tray  17  is rotated from the opened position to the closed position, the drive gear  121  is rotated in the counterclockwise direction in  FIG.  3   , and the rack gear  123  is moved in the right direction. Thus, the opening/closing gear  91  is rotated in the counterclockwise direction of  FIG.  3   . As shown in  FIG.  4   , when the discharge tray  17  is turned to the opened position, the opening/closing gear  91  is rotated around the support shaft  87  by about 90 degrees from the initial posture. The posture of the opening/closing gear  91  at this time is referred to as a rotated posture. Thus, the opening/closing gear  91  is rotated from the initial posture to the turned posture by the closing operation in which the discharge tray  17  is turned from the opened position to the closed position, and the opening/closing gear  91  is rotated from the turned posture to the initial posture by the opening operation in which the discharge tray  17  is turned from the closed position to the open position. 
     Next, the drive side coupling  115  will be described with reference also to  FIG.  6 A  and  FIG.  6 B .  FIG.  6 A  and  FIG.  6 B  are views showing the drive side coupling  115  and the opening/closing gear  91  when viewed from the front side. The drive side coupling  115  is a cylindrical member, and three coupling pieces along the circumferential direction are formed on one end surface. The three coupling pieces are arranged at predetermined intervals along the circumferential direction. The drive side coupling  115  is connected to a drive source (not shown) disposed in the housing  3 , and is rotatable in a predetermined direction. The drive side coupling  115  is supported so as to be movable in the front-and-rear direction between a coupling position protruding to the hollow space of the housing  3  (the container storage part  43 ) through the opening  89  of the rear side plate, and a non-coupling position retreating from the hollow space of the housing  3 , in a posture where the end surface on which the coupling pieces are formed faces forward. 
     The drive side coupling  115  is biased toward the coupling position, and rotatably stored in a cylindrical cam member (not shown). A cam is formed around the inner circumferential surface of the cam member, and a gear is formed around the outer circumferential surface along the circumferential direction. The cam member is rotatably supported by a bush (not shown) fixed to the opening  89  of the rear side plate. A cam follower with which the cam of the cam member is engaged is formed in the bush. When the cam member is rotated, the cam of the cam member is guided by the cam follower of the bush, and the cam member moves in the front-and-rear direction. As a result, the drive side coupling  115  moves together with the cam member to the coupling position and to the non-coupling position. 
     When the drive side coupling  115  is moved to the coupling position while the toner container  41  is stored in each individual storage part of the container storage part  43 , the drive side coupling  115  is engaged with the container side coupling  75  (see  FIG.  2   ) of the toner container  41 . By engaging the drive side coupling  115  with the container side coupling  75  in this manner, the rotating of the drive side coupling  115  is transmitted to the second gear  73 . This permits the agitating paddle  55  and the supply screw  53  rotating. On the other hand, when the drive side coupling  115  is moved to the non-coupling position, the engagement of the drive side coupling  115  with the container side coupling  75  is released. 
     The cam member and the opening/closing gear  91  are connected by a link member  131  as shown in  FIG.  6 A  and  FIG.  6 B . One end of the link member  131  is rotatably connected to the opening  103  formed in the flat plate portion  93  of the opening/closing gear  91 . A rack gear  131   a  meshing with the gear of the cam member is formed at the other end of the link member  131 . 
     As described above, when the rack gear  123  is moved in accordance with the opening/closing operation of the discharge tray  17  and the opening/closing gear  91  is rotated, the cam member rotates through the link member  131 . As shown in  FIG.  6 A , in a state where the discharge tray  17  is turned to the opened position and the opening/closing gear  91  is rotated to the initial posture, the cam member is moved most rearward along the bush by the link member  131 , and the drive side coupling  115  is moved to the non-coupling position. As shown in  FIG.  6 B , when the discharge tray  17  is turned to the closed position and the opening/closing gear  91  is rotated to the turned posture, the cam member is moved most forward along the bush by the link member  131 , and the drive side coupling  115  is moved to the coupling position. 
     The attaching operation of the toner container  41  in the image forming apparatus  1  having the above configuration will be described with reference to  FIG.  3   ,  FIG.  4   ,  FIG.  7   ,  FIG.  8 A  and  FIG.  8 B .  FIG.  7   ,  FIG.  8 A  and  FIG.  8 B  are views showing the toner container  41  when viewed from the rear side. The shutter  57  of the toner container  41  is rotated in the closed posture. 
     When the toner container  41  is attached, as shown in  FIG.  3   , the discharge tray  17  is turned to the opened position to open the container storage part  43 . The rack gear  123  is moved to the leftmost position, and the opening/closing gear  91  is rotated to the initial posture. That is, as shown in  FIG.  7   , the opening/closing gear  91  is rotated so that the engagement piece  111  of the engagement protrusion  97  protrudes directly downward. The guide pieces  113  are respectively positioned on both sides of the engagement piece  111 . Spaces along the upper-and-lower direction are formed between the engagement piece  111  and both guide pieces  113 . The drive side coupling  115  is moved to the non-coupling position. 
     As shown in  FIG.  7   , the toner container  41  is inserted downward along the adjacent guide projections  81  of the corresponding individual storage part. At this time, the lock member  85  supported by the guide protrusion  81  is pushed into the guide protrusion  81  against the biasing force of the spring by the housing  51  of the toner container  41 . 
     As the toner container  41  is inserted downward, as shown in  FIG.  8 A , the engagement protrusion  61  of the shutter  57  is engaged with the engagement protrusion  97  of the opening/closing gear  91 . Specifically, the engagement piece  111  of the opening/closing gear  91  enters the slit  61   a  of the engagement protrusion  61  of the shutter  57 . At this time, the engagement protrusion  61  of the shutter  57  is guided downward along both guide pieces  113  of the opening/closing gear  91 , and is fitted between both guide pieces  113 . Alternatively, one guide piece  113  of the opening/closing gear  91  is fitted between the engagement protrusion  61  and the interference projection  63  of the shutter  57 . As a result, the shutter  57  and the opening/closing gear  91  are engaged with each other, and the front and rear ends of the housing  51  of the toner container  41  are placed on the stepped portions  83  of the front and rear side plates. Further, the lock member  85  is biased by the spring to engage with the recess  51   a . As a result, the toner container  41  is attached to the individual storage part. When the engagement piece  111  enters the slit  61   a , the engagement piece  111  of the opening/closing gear  91  is slightly elastically deformed, and a load is applied to the user by the friction between them. When the engagement piece  111  is completely inserted into the slit  61   a , the engagement piece  111  of the opening/closing gear  91  is elastically returned to give the user a click feeling. 
     After the toner container  41  is attached, the discharge tray  17  is turned to the closed position. Then, the rack gear  123  is moved and the opening/closing gear  91  is rotated. Thus, the shutter  57  engaged with the opening/closing gears  91  rotates along the duct  51   b . When the discharge tray  17  is fully turned to the closed position, the opening/closing gear  91  is rotated to the turned posture, as shown in  FIG.  8 B . Then, the shutter  57  is rotated to the opened posture together with the opening/closing gear  91 . Thus, the communication port of the shutter  57  communicates with the supply port of the duct  51   b , and the toner can be supplied through the supply port. As described above, the opening/closing gear  91  and the rack gear  123  constitute an opening/closing mechanism which closes the supply port by rotating the shutter  57  in one direction in accordance with the opening operation of the discharge tray  17 , and opens the supply port by rotating the shutter  57  in the other direction in accordance with the closing operation of the discharge tray  17 . 
     Further, with the rotating of the opening/closing gear  91 , the cam member moves forward through the link member  131  to move the drive side coupling  115  from the non-coupling position to the coupling position. Thus, the drive side coupling  115  is engaged with the container side coupling  75 , and the rotating force of the drive source can be transmitted to the agitating paddle  55  and the supply screw  53 . 
     When the discharge tray  17  is completely turned to the opened position described above, the toner container  41  is stored in the corresponding individual storage part, and the toner can be supplied from the toner container  41 . On the other hand, when the discharge tray  17  is not turned to the normal opened position, the opening/closing gear  91  is not rotated to the initial posture. 
     For example, as shown in  FIG.  9 A  and  FIG.  9 B , in a case where the opening/closing gear  91  is not rotated to the initial posture, that is, the engagement piece  111  is not rotated to the lowest position, when the toner container  41  is inserted into the individual storage part, the interference projection  63  of the shutter  57  comes into contact with the guide piece  113  of the opening/closing gear  91  to make it impossible for the toner container to be moved downward. That is, the toner container  41  is not completely attached to the container storage part  43 , and is lifted to some extent above the container storage part  43 . As described above, the interference protrusion  63  of the shutter  57  is an example of an interference portion that prevents the toner container  41  from being attached to the container storage part  43  when the discharge tray  17  is not disposed in the normally opened position. 
     The user can easily and visually confirm that the toner container  41  is lifted above the container storage part  43 . Further, when the discharge tray  17  is closed, the discharge tray  17  interferes with the lifted toner container  41 . Thus, this makes the user notice that the toner container  41  is not properly attached. Then, for example, after the user detaches the toner container  41  temporarily, he correctly turns the discharge tray  17  to the opened position to reattach the toner container  41 . 
     If the shutter  57  is not provided with the interference projection  63 , even in a case where the discharge tray  17  is not turned to the normal opened position as shown in  FIG.  10   , the toner container  41  may be attached to the container storage part  43 . In this case, since the engagement protrusion  61  of the shutter  57  is not engaged with the engagement protrusion  97  of the opening/closing gear  91 , even if the discharge tray  17  is turned to the closed position, the shutter  57  is not rotated and the supply port of the toner container  41  is not opened. If the image forming operation is carried out in such a state, the toner is not supplied from the toner container  41  to the developing unit  31 , and problems such as insufficient image density may occur. 
     As is clear from the above description, according to the present disclosure, in a case where the discharge tray  17  is not turned to the normal opened position, the toner container  41  interferes with the opening/closing gear  91 , and the toner container  41  cannot be attached to the container storage part  43 . In other words, it is possible to prevent the toner container  41  from being attached to the container storage part  43  under a state where the discharge tray  17  is half-opened. In a state where the toner container  41  interferes with the opening/closing gear  91 , the toner container is lifted above the container storage part  43  (the housing  3 ), so that the user can easily and visually confirm whether the toner container  41  is lifted. Further, when the toner container  41  is lifted above the container storage part  43 , the discharge tray  17  cannot be turned to the closed position. Therefore, the user can surely confirm that the toner container  41  is not correctly attached to the container storage part  43  (the incorrect attachment). 
     Further, by providing the interference projection  63  in the shutter  57 , the attaching of the toner container  41  in a state where the discharge tray  17  is half-opened can be prevented by using the guide piece  113  originally provided in the opening/closing gear  91 . 
     Further, since the drive side coupling  115  and the container side coupling  75  can be coupled or uncoupled in accordance with the rotating of the opening/closing gear  91 , the constitution of the transmission mechanism of the rotating force to the agitating paddle  55  and the supply screw  53  of the toner container  41  can be simplified. 
     The above embodiment shows an example where the interference projection  63  is provided in the shutter  57  of the toner container  41 , but the interference projection  63  may be provided in the housing  51  of the toner container  41 . However, in the present disclosure, since the shutter  57  and the opening/closing gear  91  are engaged with each other when the toner container  41  is attached to the container storage part  43 , by providing the interference projection  63  in the shutter  57 , the interference projection  63  can be reliably brought into contact with the opening/closing gear  91  when the discharge tray  17  is not turned to the normal opened position. 
     The above embodiment shows an example where the discharge tray  17  as a cover is turned to the opened position and to the closed position, but the cover may be moved in the upper-and-lower direction to the opened position and to the closed position. In this case, the cover may be provided with a rack gear along the upper-and-lower direction, and the rack gear may be meshed with the rack gear  123  of the opening/closing mechanism through a pinion gear. By moving the cover in the upper-and-lower direction, the rack gear moves in the upper-and-lower direction, and the rack gear  123  can be moved in the horizontal direction through the pinion gear. 
     Although the present disclosure has been described with respect to specific embodiments, the present disclosure is not limited to the above embodiments. Those skilled in the art will be able to modify the above embodiments without departing from the scope and intent of the present disclosure.