Patent Publication Number: US-8983343-B2

Title: Image forming apparatus and toner case

Description:
INCORPORATION BY REFERENCE 
     This application is based on and claims the benefit of priority from Japanese Patent application No. 2012-099150 filed on Apr. 24, 2012, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     The present disclosure relates to an image forming apparatus and a toner case installed therein. 
     An image forming apparatus, such as an electrostatic copying machine, a laser printer or an electrostatic facsimile, carries out the development process by supplying a toner (a developer) from a development device to an electrostatic latent image formed on the surface of a photosensitive drum or the like. The toner used in such development process is supplied from a toner case, such as a toner container or an intermediate hopper, to the development device. 
     In the image forming apparatus, by repeatedly carrying out the above-mentioned development process, the toner in the toner case accordingly decreases, and then, when the toner in the toner case runs out, the toner case is replaced. Therefore, the toner case is detachably installed to an installed part provided in the image forming apparatus. 
     In order to improve operability for installing and detaching the toner case to the image forming apparatus and force for holding the toner case in the image forming apparatus, various different structures are designed so far. For example, one image forming apparatus provided with an installed part, a fixing member and a biasing member is disclosed. To the installed part, a toner case is detachably installed. The fixing member is arranged to move in an axial direction accompanying to the installing action of the toner case to the installed part. The biasing member is arranged to bias the fixing member to one side in the axial direction. In such technique, by making the toner case press an inclined face formed on the fixing member, the fixing member moves to another side in the axial direction against the biasing force of the biasing member. Then, when the bottom face of the toner case is released from the fixing member, the toner case is stopped in an engaged state by the fixing member by biasing force of the biasing member. 
     However, in the above-mentioned structure, it is necessary to continue pressing the toner case to the installed part side against the biasing force of the biasing member until the toner case is stopped in an engaged state by the fixing member after the toner case comes into contact with the fixing member. Therefore, a working load of workers, such as a user or a serviceman, undertaking installation/detachment work of the toner case is increased. 
     SUMMARY 
     In accordance with an embodiment of the present disclosure, an image forming apparatus includes a toner case and an installed part. The toner case includes a discharge port configured to discharge a toner. To the installed part, the toner case is detachably installed. On the circumference of the toner case, a locking piece is provided. The installed part includes a locking member configured to cover at least a part of the circumference of the toner case. The locking member has an insertion depression, an engaging piece and a biasing member. The insertion depression is arranged along an installing direction of the toner case to the installed part. The insertion depression is configured to be capable of insertion of the locking piece. The engaging piece is configured to move between a protrusive position arranged to protrude to the insertion depression at predetermined length and a withdrawn position arranged to withdraw further than the protrusive position from the insertion depression in intersecting directions with the installing direction. The biasing member is configured to bias the engaging piece to the protrusive position side. In the insertion depression, a first position, a second position being further than the first position in the installing direction and a third position being further than the second position in the installing direction are provided. While the toner case is installed to the installed part, when the locking piece is inserted to the first position, the locking piece presses the engaging piece so that the engaging piece moves from the protrusive position to the withdrawn position against biasing force of the biasing member. Then, when the locking piece is inserted to the second position, the engaging piece presses the locking piece to the far side in the installing direction by biasing force of the biasing member. And then, when the locking piece is inserted to the third position, the engaging piece stops the locking piece in an engaged state so that the movement of the locking piece toward the near side in the installing direction is restricted. 
     Furthermore, in accordance with an embodiment of the present disclosure, a toner case is detachably installed to an installed part of an image forming apparatus. The toner case includes a discharge port configured to discharge a toner and a locking piece provided on its circumference. The installed part of the image forming apparatus includes a locking member configured to cover at least apart of the circumference of the toner case. The locking member includes an insertion depression, an engaging piece and a biasing member. The insertion depression is arranged along an installing direction of the toner case to the installed part. The insertion depression is configured to be capable of insertion of the locking piece. The engaging piece is configured to move between a protrusive position arranged to protrude to the insertion depression at predetermined length and a withdrawn position arranged to withdraw further than the protrusive position from the insertion depression in intersecting directions with the installing direction. The biasing member is configured to bias the engaging piece to the protrusive position side. In the insertion depression, a first position, a second position being further than the first position in the installing direction and a third position being further than the second position in the installing direction are provided. While the toner case is inserted to the installed part, when the locking piece is inserted to the first position, the locking piece presses the engaging piece so that the engaging piece moves from the protrusive position to the withdrawn position against biasing force of the biasing member. Then, when the locking piece is inserted to the second position, the engaging piece presses the locking piece to the far side in the installing direction by biasing force of the biasing member. And then, when the locking piece is inserted to the third position, the engaging piece stops the locking piece in an engaged state so that the movement of the locking piece toward the near side in the installing direction is restricted. 
     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 schematic diagram schematically showing a printer according to an embodiment of the present disclosure. 
         FIG. 2  is a back right perspective view showing a toner container in the printer according to the embodiment of the present disclosure. 
         FIG. 3  is a back left perspective sectional view showing the printer in a situation, in which a case side shutter opens a discharge port and a development device side shutter opens a replenishment port, according to the embodiment of the present disclosure. 
         FIG. 4  is a right side view the toner container in the printer according to the embodiment of the present disclosure. 
         FIG. 5  is a back left perspective view showing the toner container in the printer according to the embodiment of the present disclosure. 
         FIG. 6  is an exploded perspective view the toner container in the printer according to the embodiment of the present disclosure. 
         FIG. 7  is a schematic diagram schematically showing an image forming unit in the printer according to an embodiment of the present disclosure. 
         FIG. 8  is a front left perspective view showing the image forming unit in the printer according to the embodiment of the present disclosure. 
         FIG. 9  is a back right perspective view showing the image forming unit in the printer according to the embodiment of the present disclosure. 
         FIG. 10  is a sectional view showing a locking member in the printer according to the embodiment of the present disclosure. 
         FIG. 11  is a back right perspective view showing the printer in a situation, in which the toner container is held above a development device, according to the embodiment of the present disclosure. 
         FIGS. 12A to 12D  are sectional views showing the printer, in respective stages of fixing of a locking piece to the locking member, according to the embodiment of the present disclosure. 
         FIGS. 13A to 13C  are sectional views showing the printer, in respective stages of fixing of a fixing piece to a fixing member, according to the embodiment of the present disclosure. 
         FIG. 14  is a back left perspective sectional view showing the printer in a situation, in which the case side shutter closes the discharge port and the development device side shutter closes the replenishment port, according to the embodiment of the present disclosure. 
         FIG. 15  is a back right perspective view showing the printer in a situation, in which the toner container is installed to an installed part of the development device, according to the embodiment of the present disclosure. 
         FIGS. 16A and 16B  are sectional views showing the printer, in respective stages of detachment of the toner container from the installed part of the development device, according to the embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     With reference to  FIG. 1 , the entire structure of an electrographic printer  1  as an image forming apparatus will be described.  FIG. 1  is a schematic diagram schematically showing the printer according to an embodiment of the present disclosure. Hereinafter, it will be described so that the front side of the printer  1  is positioned at the left-hand side of  FIG. 1 . 
     The printer  1  includes a box-formed printer main body  2 . In a lower part of the printer main body  2 , a sheet feeding cartridge  3  configured to store sheets (not shown) is installed and, on the top surface of the printer main body  2 , an ejecting tray  4  is mounted. On the top surface of the printer main body  2 , an upper cover  5  is openably/closably attached in front of the sheet ejecting tray  4  and, below the upper cover  5 , a toner container  6  as a toner case is installed. 
     In an upper part of the printer main body  2 , an exposure device  7  is installed below the sheet ejecting tray  4 . The exposure device  7  is composed of a laser scanning unit (LSU). Below the exposure device  7 , an image forming unit  8  is installed. In the image forming unit  8 , a photosensitive drum  10  as an image carrier is rotatably installed. Around the photosensitive drum  10 , a charger  11 , a development device  12 , a transfer roller  13  and a cleaning device  14  are located along a rotating direction (refer to arrow X in  FIG. 1 ) of the photosensitive drum  10 . 
     In the printer main body  2 , a sheet conveying path  15  is arranged. At an upper stream end of the conveying path  15 , a sheet feeder  16  is positioned and, at an intermediate stream part of the conveying path  15 , a transferring unit  17  constructed of the photosensitive drum  10  and the transfer roller  13  is positioned. Furthermore, at a lower stream part of the conveying path  15 , a fixing device  18  is positioned and, at a lower stream end of the conveying path  15 , a sheet ejecting unit  20  is positioned. Below the conveying path  15 , an inversion path  21  for duplex printing is arranged. 
     Next, the operation of forming an image by the printer  1  having such a configuration will be described. 
     When the power is supplied to the printer  1 , various parameters are initialized and initial determination, such as temperature determination of the fixing device  18 , is carried out. Subsequently, in the printer  1 , when image data is inputted and a printing start is directed from a computer or the like connected with the printer  1 , image forming operation is carried out as follows. 
     First, the surface of the photosensitive drum  10  is electrically charged by the charger  11 . Then, exposure corresponding to the image data on the photosensitive drum  10  is carried out by a laser (refer to two-dot chain line P in  FIG. 1 ) from the exposure device  7 , thereby forming an electrostatic latent image on the surface of the photosensitive drum  10 . Subsequently, the electrostatic latent image is developed to a toner image with a toner (a developer) in the development device  12 . 
     On the other hand, a sheet fed from the sheet feeding cartridge  3  by the sheet feeder  16  is conveyed to the transferring unit  17  in a suitable timing for the above-mentioned image forming operation, and then, the toner image on the photosensitive drum  10  is transferred onto the sheet in the transferring unit  17 . The sheet with the transferred toner image is conveyed to a lower stream on the conveying path  15  to go forward to the fixing device  18 , and then, the toner image is fixed on the sheet in the fixing device  18 . The sheet with the fixed toner image is ejected from the sheet ejecting unit  20  to the sheet ejecting tray  4 . Toner remained on the photosensitive drum  10  is collected by the cleaning device  14 . 
     Next, with reference to  FIGS. 2-6 , the toner container  6  will be described in detail.  FIG. 2  is a back right perspective view showing the toner container in the printer according to the embodiment of the present disclosure.  FIG. 3  is a back left perspective sectional view showing the printer in a situation, in which a case side shutter opens a discharge port and a development device side shutter opens a replenishment port, according to the embodiment of the present disclosure.  FIG. 4  is a right side view the toner container in the printer according to the embodiment of the present disclosure.  FIG. 5  is a back left perspective view showing the toner container in the printer according to the embodiment of the present disclosure.  FIG. 6  is an exploded perspective view the toner container in the printer according to the embodiment of the present disclosure. 
     Arrow Fr suitably put on each figure indicates the front side of the printer  1  ( FIG. 7  and more are also illustrated similarly).  FIG. 2  is the back right sectional view,  FIG. 3  is the back left perspective sectional view and  FIG. 5  is the back left perspective view. Therefore, in  FIGS. 2 ,  3  and  5 , the left-hand and right-hand sides of the figure are converse to the actual left-hand and right-hand sides. 
     As shown in  FIG. 2 , the toner container  6  includes a box-formed case main body  22  with a opened top surface, a conveying screw  23 , a stirring paddle  24 , a covering body  25 , a lever  26 , a transmitting member  27  and a case side shutter  28 . The conveying screw  23  is installed in a lower rear part of the case main body  22 . The stirring paddle  24  is installed near a center part of the case main body  22 . The covering body  25  covers the top surface of the case main body  22 . The lever  26  is attached to a right end of the case main body  22 . The transmitting member  27  is placed on the right end of the case main body  22  together with the lever  26 . The case side shutter  28  is attached on a lower rear part of the right end of the case main body  22 . The transmitting member  27  is omitted in  FIG. 4 . 
     The case main body  22  is formed in an extended-shape in left and right directions or a horizontal direction to contain the toner. On the circumference of a top end of the case main body  22 , a main body side flange  30  is formed. As shown in  FIG. 3 , at the right bottom end of the case main body  22 , a cylinder-formed discharge duct  31  is protruded to a right direction and, in a bottom of the discharge duct  31 , a discharge port  32  configured to discharge the toner is bored. On the circumference of a lower part of the discharge duct  31 , a sealing member  33  is attached and, in the sealing member  33 , a communication port  34  is bored at a correspondent position to the discharge port  32 . 
     As shown in  FIG. 4 , at the center of a right end wall  35  of the case main body  22 , a cylinder-formed boss  37  having a penetrated hole  36  is protruded to a right direction (an outside direction). On a right surface (an outside surface) of the right end wall  35  of the case main body  22 , a first restrain rib  38  is protruded to an upper backward direction of the boss  37 . On the right surface of the right end wall  35  of the case main body  22 , a second restrain rib  40  is protruded to an upper forward direction of the boss  37 . On the right surface of the right end wall  35  of the case main body  22 , a columnar protrusion  42  is formed below the first restrain rib  38 . 
     As shown in  FIG. 5 , in a front part of a left end wall  43  of the case main body  22 , a pedestal  44  is protruded to a left direction (an outside direction), and on the pedestal  44 , an integrated circuit (IC) tag  45  for wireless communications is fixedly attached. In a rear part of the left end wall  43  of the case main body  22 , a toner filling port  46  is formed behind the pedestal  44  and the toner filling port  46  is closed by a cap  47 . 
     On a left surface (corresponding to a part of the circumference of the toner container  6 ) of the left end wall  43  of the case main body  22 , a locking piece  48  is attached below and behind the toner filling port  46 . The locking piece  48  is formed in an extended-shape in a lower backward inclined direction (hereinafter, called an installing direction; refer to arrow Y in  FIG. 5 ). In an upper part of a front surface of the locking piece  48 , a depression  50  is formed, and below the depression  50 , an engaging protrusion  51  is protruded in a front direction. 
     As shown in  FIG. 2  and other figure, the conveying screw  23  is formed in an extended-shape in the horizontal direction. The conveying screw  23  includes a bar-formed rotating shaft  52  and a spiral fin  53  concentrically mounted on the circumference of the rotating shaft  52 . As shown in  FIG. 3 , right side parts of the rotating shaft  52  and spiral fin  53  are inserted into the discharge duct  31 . A right end of the rotating shaft  52  protrudes from the discharge duct  31  in the right direction and, onto the protruding part, a conveying gear  54  (refer to  FIG. 2 ) is fixedly attached. 
     As shown in  FIG. 2 , the stirring paddle  24  is located above and in front of the conveying screw  23  and formed in an extended-shape in the horizontal direction. The stirring paddle  24  includes a frame plate-formed supporting frame  55  and a sheet-formed stirring fin  56  supported by the supporting frame  55 . Left and right ends of the supporting frame  55  are pivotally supported by the right end wall  35  and left end wall  43  of the case main body  22  via bearings  57  (refer to  FIG. 3 ). Hereinafter, each bearing  57  is called as “a bearing  57  of a stirring paddle  24 ”). As shown in  FIG. 4  and other figure, on the bearing  57  of the stirring paddle  24  attached onto the right end wall  35 , an engaging reception  58  is formed at a correspondent position to the penetrated hole  36  of the boss  37 . The stirring fin  56  is formed out of plastic sheet, e.g. lumirror. 
     As shown in  FIG. 2 , on the circumference of the covering body  25 , a covering body side flange  60  is formed in the correspondent form to the main body side flange  30  of the case main body  22 . The main body side flange  30  and covering body side flange  60  are ultrasonic-welded together so that the case main body  22  and covering body  25  are unified. 
     As shown in  FIG. 4  and other figure, the lever  26  includes a lever main body  61  with a circular profile in a side view. The lever main body  61  includes a small-diameter cylinder  62 , a large-diameter cylinder  63  attached around the circumference of the small-diameter cylinder  62  and four radially extended connecters  64  connecting the small-diameter cylinder  62  and large-diameter cylinder  63  with each other. 
     The small-diameter cylinder  62  is fitted onto the circumference of the boss  37  arranged on the right end wall  35  of the case main body  22 . Accordingly, the lever  26  is rotatably supported onto the case main body  22 . On an upper part of the large-diameter cylinder  63 , a gripper  65  is protruded. On the large-diameter cylinder  63 , a protruding piece  66  is formed in front of the gripper  65 . On the circumference of a lower rear part of the large-diameter cylinder  63 , a lever side gear  67  is formed. 
     As shown in  FIG. 6  and other figure, the transmitting member  27  includes a disc-formed transmitting member main body  68 . On aright surface (an outside surface) of the transmitting member main body  68 , a transmission coupling  70  is protruded in the form of a triangle pole in a side view. On a left surface (an inside surface) of the transmitting member main body  68 , an engaging piece  71  is protruded. The engaging piece  71  is inserted into the penetrated hole  36  formed in the boss  37  of the case main body  22 , and then, engaged with the engaging reception  58  (refer to  FIG. 4  and other figure) formed on the bearing  57  of the stirring paddle  24 . Accordingly, the transmitting member  27  and stirring paddle  24  are connected with each other to rotate in a body. 
     As shown in  FIG. 2 , on the circumference of the transmitting member main body  68 , a transmission gear  72  is formed. The transmission gear  72  meshes with the conveying gear  54  fixedly attached onto the rotating shaft  52  of the conveying screw  23 , thereby rotating the conveying screw  23  in accordance with the rotation of the transmitting member  27 . 
     As shown in  FIG. 6 , the case side shutter  28  is formed in a cylinder-liked shape. The case side shutter  28  is rotatably fitted onto the circumference of the discharge duct  31  of the case main body  22 . In a lower surface of the case side shutter  28 , a discharge aperture  73  is bored. As shown in  FIG. 3  and other figure, the discharge aperture  73  is formed at a correspondent position to the discharge port  32  of the case main body  22  and the communication port  34  of the sealing member  33 . 
     As shown in  FIG. 4  and other figure, on the case side shutter  28 , a roughly fan-formed guiding piece  74  is protruded. In the guiding piece  74 , an arc-formed guiding hole  75  is formed and, with the guiding hole  75 , the protrusion  42  of the case main body  22  is engaged. 
     As shown in  FIG. 6  and other figure, in the case side shutter  28 , a gear box  76  is attached and the gear box  76  houses the conveying gear  54 . In the gear box  76 , a communication aperture  77  is formed so that it is possible to house the conveying gear  54  in the gear box  76  via the communication aperture  74 . 
     As shown in  FIG. 4  and other figure, the case side shutter  28  is provided with a shutter side gear  78 . The shutter side gear  78  meshes with the lever side gear  67  of the lever  26 , thereby turning the case side shutter  28  in the opposite direction to the lever  26  in accordance with the turn of the lever  26 . On the right end of the case side shutter  28 , a fixing piece  80  is attached. The fixing piece  80  includes a pair of plane parts  81  facing to each other and a pair of curving parts  82 , each of which is connected with respective ends of the plane parts  81 . The fixing piece  80  is formed with an elliptic section. Outside a lower part of the case side shutter  28 , a pressing protrusion  83  is formed. 
     Next, with reference to  FIGS. 7-10 , the development device  12  will be described in detail.  FIG. 7  is a schematic diagram schematically showing the image forming unit in the printer according to an embodiment of the present disclosure.  FIG. 8  is a front left perspective view showing the image forming unit in the printer according to the embodiment of the present disclosure.  FIG. 9  is a back right perspective view showing the image forming unit in the printer according to the embodiment of the present disclosure.  FIG. 10  is a sectional view showing the locking member in the printer according to the embodiment of the present disclosure. 
     As shown in  FIG. 7 , the development device  12  is integrated with the photosensitive drum  10 , charger  11  and cleaning device  14  so that an image forming unit  85  is composed. The image forming unit  85  is configured to be pulled out of the printer main body  2  in an upper forward direction and detachably installed in the printer main body  2 . 
     The development device  12  is provided with a box-formed development device main body  86 . At the center inside the development device main body  86 , a partition  87  extending in upper and lower directions or a perpendicular direction is formed and, in front and behind the partition  87 , stirring members  88  are respectively installed. Each stirring member  88  is rotatably supported onto the development device main body  86 . Inside the development device main body  86 , below and behind the rear stirring member  88 , a developing roller  90  is installed. The developing roller  90  is rotatably supported onto the development device main body  86  and comes into contact with the surface of the photosensitive drum  10 . 
     As shown in  FIG. 8 , on the top surface side of a top wall  91  of the development device main body  86 , an installed part  92  is provided so that the toner container  6  is detachably installed into the installed part  92  as follows. In a right side part of the installed part  92 , a replenishment port  93  is bored in the perpendicular direction, and around the replenishment port  93 , a sealing member  94  is fixedly attached. The sealing member  94  is made of elastic material, e.g. sponge. In the sealing member  94 , a replenishment aperture  95  is formed at a correspondent position to the replenishment port  93 . 
     In the installed part  92 , a development device side shutter  96  is attached. The development device side shutter  96  is formed in an extended plane-liked shape in the horizontal direction. At a left end of the development device side shutter  96 , a supporting pivot  97  is provided so that the development device side shutter  96  turns around the supporting pivot  97  in a forward or backward direction along the top surface side of the top wall  91  of the development device main body  86 , thereby opening or closing the replenishment port  93  and replenishment aperture  95 . 
     On a front end of the installed part  92 , a handle  99  is formed. On the right end of the installed part  92 , a driving mechanism  98  is protrusively attached. The driving mechanism  98  includes a drive coupling  100  in the form of a triangle pole in a side view which is connected with a drive unit (not shown), such as a motor. 
     On a right end of the installed part  92 , a fixing member  101  is protrusively attached behind the driving mechanism  98 . On a left surface (an inside surface) of the fixing member  101 , a line-formed guiding gap  102  is formed along the installing direction (refer to arrow Y in  FIG. 8 ). On the rear bottom side of the guiding gap  102  (at a far side in the installing direction), a fixing gap  103  is formed with a circular section. 
     As shown in  FIG. 9 , on a left end of the installed part  92 , a locking member  104  is protruded. On a right surface (an inside surface) of the locking member  104 , a guiding depression  105  is formed in an arc shape curved in a downward direction. As shown in  FIG. 10 , on the right surface of the locking member  104 , an insertion depression  106  connected with a lower end of the guiding depression  105  is formed. The insertion depression  106  is arranged along the installing direction (refer to arrow Y in  FIG. 10 ). As shown in  FIGS. 12A-12D , in the insertion depression  106 , there are provided a first position A 1 , a second position A 2  being further than the first position A 1  in the installing direction and a third position A 3  being further than the second position A 2  in the installing direction. 
     As shown in  FIG. 10  and other figure, in front of the insertion depression  106 , a housing part  107  is arranged to extend in the forward and backward directions. The housing part  107  communicates into the insertion depression  106  via a communication hole  108 . In the housing part  107 , an engaging piece  110  is housed. The engaging piece  110  is configured to move between a protrusive position (refer to solid line in  FIG. 10 ) protruded to the insertion depression  106  at predetermined length and a withdrawn position (refer to two-dot chain line in  FIG. 10 ) withdrawn further than the protrusive position from the insertion depression  106  in intersecting directions (the forward and backward directions in the embodiment) with the installing direction. 
     In a part of the engaging piece  110  to be protruded to the insertion depression  106 , a first inclined face  111  is formed to incline so as to go toward the far side in the installing direction and protrude to the insertion depression  106 . In the engaging piece  110 , a second inclined face  112  is formed in succession from the first inclined face  111 . The second inclined face  112  is arranged at a further side than the first inclined face  111  in the installing direction. The second inclined face  112  inclines to go toward the far side in the installing direction and withdraw from the insertion depression  106 . In the engaging piece  110 , an engaging depression  116  is formed at a further side than the second inclined face  112  in the installing direction. At the front side of the engaging piece  110 , a spring depression  113  is formed and, in spring depression  113 , a spring reception  114  is formed. Between the spring reception  114  and housing part  107 , a coil spring  115  as a biasing member is installed so that the engaging piece  110  is biased to the protrusive position side by the coil spring  115 . 
     In the aforementioned configuration, a method of installing the toner container  6  into the installed part  92  of the development device  12  will be described with reference to  FIGS. 11-15 .  FIG. 11  is a back right perspective view showing the printer in a situation, in which the toner container is held above the development device, according to the embodiment of the present disclosure.  FIGS. 12A to 12D  are sectional views showing the printer, in respective stages of fixing of the locking piece to the locking member, according to the embodiment of the present disclosure.  FIGS. 13A to 13C  are sectional views showing the printer, in respective stages of fixing of a fixing piece to a fixing member, according to the embodiment of the present disclosure.  FIG. 14  is a back left perspective sectional view showing the printer in a situation, in which the case side shutter closes the discharge port and the development device side shutter closes the replenishment port, according to the embodiment of the present disclosure.  FIG. 15  is a back right perspective view showing the printer in a situation, in which the toner container is installed in an installed part of the development device, according to the embodiment of the present disclosure. The transmitting member  27  is omitted in  FIG. 13 . 
     In order to install the toner container  6  into the installed part  92  of the development device  12 , first, as shown in  FIG. 11 , after the toner container  6  is held above the development device  12 , the toner container  6  is taken down to the development device  12  along the installing direction (refer to arrow Y in  FIG. 11 ). Then, the locking piece  48  of the toner container  6  is guided by the guiding depression  105  and taken down so that the locking piece  48  is inserted to the insertion depression  106  with the lower end foremost. Accordingly, as shown in  FIG. 12A , the lower end of the locking piece  48  comes into contact with the first inclined face  111  of the engaging piece  110 . 
     Subsequently to such a situation, as shown in  FIG. 12B , when the locking piece  48  is more taken down and the lower end of the locking piece  48  is inserted to the first position A 1  in the insertion depression  106 , the lower end of the locking piece  48  presses the first inclined face  111  of the engaging piece  110  and the engaging piece  110  moves from the protrusive position to the withdrawn position against biasing force of the coil spring  115 . At this moment, the first inclined face  111  of the engaging piece  110  presses the locking piece  48  toward a near side in the installing direction. 
     Subsequently to such a situation, as shown in  FIG. 12C , when the locking piece  48  is further taken down and the lower end of the locking piece  48  is inserted to the second position A 2  being further than the first position A 1  in the installing direction, the second inclined face  112  of the engaging piece  110  comes into contact with the engaging protrusion  51  of the locking piece  48 . Accordingly, the second inclined face  112  of the engaging piece  110  presses the engaging protrusion  51  of the locking piece  48  toward the far side in the installing direction by the biasing force of the coil spring  115 . 
     Subsequently to such a situation, as shown in  FIG. 12D , when the locking piece  48  is furthermore taken down and the lower end of the locking piece  48  is inserted to the third position A 3  being further than the second position A 2  in the installing direction, the contact state of the second inclined face  112  of the engaging piece  110  with the engaging protrusion  51  of the locking piece  48  is released. Then, the engaging piece  110  moves from the withdrawn position to the protrusive position by the biasing force of the coil spring  115  and the engaging protrusion  51  of the locking piece  48  engages with the engaging depression  116  of the engaging piece  110 . Accordingly, the engaging piece  110  stops the locking piece  48  in an engaged state so that the movement of the locking piece  48  toward the near side in the installing direction is restricted. In addition, a top end (a back end) of the engaging piece  110  is inserted to the depression  50  of the locking piece  48 . 
     Moreover, as shown in  FIG. 13A , in a situation before the toner container  6  is installed to the installed part  92  of the development device  12 , the fixing piece  80  is separated from the fixing member  101 . Subsequently to this situation, when the toner container  6  is installed to the installed part  92  of the development device  12 , as shown in  FIG. 13B , the fixing piece  80  passes through the guiding gap  102  and is engaged with the fixing gap  103 . 
     In such a situation, when the gripper  65  of the lever  26  is tilted backward so that the lever  26  turns, accompanying to this turn, the case side shutter  28  connected with the lever  26  turns on the case main body  22 . In accordance with the turn of the case side shutter  28 , as shown in  FIG. 13C , a phase of the fixing piece  80  to the fixing gap  103  is varied, and then, the release of the engagement of the fixing piece  80  and the fixing gap  103  are restricted. Thereby, the right end of the toner container  6  is shifted from a released state to a fixed state to the installed part  92  of the development device  12 . 
     On the other hand, in a situation before the gripper  65  of the lever  26  is tilted backward, as shown in  FIG. 14 , the case side shutter  28  closes the discharge port  32  of the case main body  22 . Subsequently to this situation, as mentioned above, when the gripper  65  of the lever  26  is tilted backward so that the case side shutter  28  turns, as shown in  FIG. 3 , the case side shutter  28  opens the discharge port  32  of the case main body  22 . In addition, accompanying to the above-mentioned turn of the case side shutter  28 , the pressing protrusion  83  of the case side shutter  28  presses the development device side shutter  96  backward. Accompanying to this press, the development device side shutter  96  turns backward and the development device side shutter  96  opens the replenishment port  93  of the development device  12 . Thereby, it is possible to feed the toner from the toner container to the development device  12 . 
     Thus, when the toner container  6  is installed to the installed part  92  of the development device  12 , as shown in  FIG. 15 , the left face of the left end wall  43  of the toner container  6  is covered by the locking member  104  and the right end of the case side shutter  28  is covered by the fixing member  101 . 
     In the embodiment, as described above, when the lower end of the locking piece  48  is inserted to the second position A 2  of the insertion depression  106 , the second inclined face  112  of the engaging piece  110  presses the locking piece  48  toward the far side in the installing direction by the biasing force of the coil spring  115 . It is therefore possible to decrease force required to move the toner container toward the far side in the installing direction. Accordingly, it is possible to decrease a working load of workers, such as a user or a serviceman, undertaking installation/detachment work of the toner container  6 . In addition, when the lower end of the locking piece  48  is inserted to the third position A 3  of the insertion depression  106 , the locking piece  48  is stopped in an engaged state by the engaging piece  110 , thereby securely fixing the toner container  6  to the installed part  92 . 
     Moreover, the second inclined face  112  of the engaging piece  110  is formed in succession from the first inclined face  111 . It is therefore possible to facilitate the shift from a state of pressing the first inclined face  111  of the engaging piece  110  by the locking piece  48  to another state of pressing the engaging protrusion  51  of the locking piece  48  by the second inclined face  112  of the engaging piece  110 . 
     Furthermore, the lever  26  is connected with the case side shutter  28 . It is therefore possible to simultaneously carry out opening and closing of the discharge port  32  accompanying to the shift between the fixed state and released state of the right end of the toner container  6 , thereby further decreasing a working load of workers undertaking installation/detachment work of the toner container  6 . Because the fixing piece  80  of the case side shutter  28  is engaged with the fixing gap  103  of the fixing member  101 , it is possible to more securely fix the toner container  6  to the installed part  92 . Particularly, because the embodiment is configured to rigidly fix both ends of the toner container  6  to the installed part  92 , even if the toner container  6  is grabbed and the image forming unit  85  is pulled out or detached, it is possible to prevent unintentional disconnect of the toner container  6  from the installed part  92 . 
     In addition, the locking piece  48  is formed in an extended-shape in the installing direction. Therefore, when the toner container  6  is installed to and detached from the installed part  92 , the locking piece  48  is guided along the installing direction by the insertion depression  106 , thereby stabilizing a posture of the toner container  6 . 
     Next, a method of detaching the toner container  6  from the installed part  92  of the development device  12  will be described with reference to mainly  FIGS. 13 and 16 .  FIGS. 13A to 13C  are sectional views showing the printer, in respective stages of fixing of a fixing piece to a fixing member, according to the embodiment of the present disclosure.  FIGS. 16A and 16B  are sectional views showing the printer, in respective stages of detachment of the toner container from the installed part of the development device, according to the embodiment of the present disclosure. 
     First, as shown in  FIG. 13C , after a situation in which the gripper  65  of the lever  26  is tilted backward, the gripper  65  of the lever  26  is tilted forward. Accordingly, as shown in  FIG. 13B , a phase of the fixing piece  80  to the fixing gap  103  is varied, and then, the engagement of the fixing piece  80  and the fixing gap  103  is made releasable, thereby shifting the right end of the toner container  6  from the fixed state to the released state to the installed part  92 . 
     In such a situation, as shown in  FIG. 13A , the fixing piece  80  is removed from the fixing member  101 . Then, because the locking piece  48  is still stopped in an engaged state by the engaging piece  110 , as shown in  FIG. 16A , the right end side of the toner container  6  turns around the left end side in a separating direction (in the embodiment, an upper direction) from the installed part  92 . Thereby, the engaged stop of the locking piece  48  with the engaging piece  110  is made releasable, and therefore, as shown in  FIG. 16B , it is possible to detach the toner container  6  from the installed part  92  of the development device  12 . 
     In the embodiment, as described above, without configuring the installed part  92  to include a mechanism for releasing the fixed state of the toner container  6  to the installed part  92 , it is possible to detach the toner container  6  from the installed part  92 . 
     Although the embodiment was described in case of forming the lever  26  and case side shutter  28  separately from each other, as another embodiment, the lever  26  and case side shutter  28  may be formed in a body. 
     Although ideas of the disclosure are applied into the toner container  6  in the embodiment, as a further embodiment, the ideas of the disclosure may be applied into another toner case (so-called “an intermediate hopper”) interposed between the toner container  6  and development device  12 . 
     Although the embodiment was described in a case where ideas of the disclosure are applied into the printer  1 , as a furthermore embodiment, the ideas of the disclosure may be applied into another image forming apparatus except the printer  1 , such as a copying machine, a facsimile or a multifunction machine. 
     While the present disclosure has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present disclosure.