Patent Publication Number: US-10768567-B2

Title: Automatic mounting apparatus and image forming apparatus including same

Description:
CLAIM OF PRIORITY 
     This application claims the benefit of Korean Patent Application No. 10-2015-0099555, filed on Jul. 14, 2015, and International Patent Application No. PCT/KR2016/007371, filed on Jul. 7, 2016, the disclosures of which are incorporated herein in their entirety by reference. 
     BACKGROUND ART 
     An image forming apparatus is an apparatus for printing an image on print media, and comprises a printer, a copier, a facsimile, and a multifunction device in which functions of a printer, a copier, and a facsimile are combined. 
     An image forming apparatus adopting electrophotography forms a visible image by scanning light to a photosensitive member charged to a predetermined potential after forming an electrostatic latent image on the surface of the photosensitive member, and by supplying a toner to the electrostatic latent image. The visible image formed on the photosensitive member is directly transferred to a print medium or transferred to the print medium through an intermediate transfer member, and the visible image transferred to the print medium is fixed by a fixing device. 
     The image forming apparatus may be provided with a cassette on which a volume of the print medium is loaded. The cassette can be mounted on the image forming apparatus in a drawable manner. Since the cassette is inserted into the image forming apparatus while the print medium is loaded thereon, a cassette mounting device is formed of a rigid material so as to withstand the weight of the cassette and the print medium loaded on the cassette. 
     The cassette mounting device is provided with a damper to prevent the impact and noise generated when the cassette is inserted into the image forming apparatus. 
    
    
     
       DESCRIPTION OF DRAWINGS 
       These and/or other aspects of the present disclosure will become apparent and more readily appreciated from the following description of the examples, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a view illustrating a configuration of an image forming apparatus according to an example. 
         FIG. 2  is a view illustrating an automatic mounting apparatus according to an example. 
         FIG. 3  is a perspective view illustrating a locking device according to an example. 
         FIG. 4  is a front view illustrating the locking device of  FIG. 3  according to an example. 
         FIG. 5  is an exploded-perspective view illustrating the locking device of  FIG. 3  according to an example. 
         FIG. 6  is a perspective view illustrating a locking device according to another example. 
         FIG. 7  is a front view illustrating the locking device of  FIG. 6  according to another example. 
         FIG. 8  is an exploded-perspective view illustrating the locking device of  FIG. 6  according to another example. 
         FIG. 9  is a perspective view illustrating the cassette of  FIG. 1  according to an example. 
         FIG. 10  is a view illustrating a portion of the cassette of  FIG. 9 . 
         FIGS. 11A to 11C  are views illustrating an operation in which the cassette of  FIG. 9  is mounted automatically according to an example. 
         FIG. 12  is a view illustrating a portion of a cassette according to another example. 
         FIGS. 13A to 13C  are views illustrating an operation in which the cassette of  FIG. 12  is mounted automatically according to another example. 
         FIGS. 14A to 14D  are views illustrating an operation when the cassette is erroneously mounted according to another example. 
         FIG. 15  is a view illustrating a configuration of a printing sheet outlet portion of the cassette according to an example. 
         FIG. 16  is a cross-sectional view illustrating the printing sheet outlet portion of the cassette according to an example. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter examples of an automatic mounting apparatus and an image forming apparatus having the same will be described in details with reference to drawings. 
       FIG. 1  is a view illustrating a configuration of an image forming apparatus according to an example. 
     In  FIG. 1 , an image forming apparatus  1  may comprise a housing  10 , and a cassette  2  on which printing sheets are loaded for storing and feeding. An opening  10   a  may be formed at the front side of the housing  10 , and the cassette  2  may be inserted into or pulled out from the image forming apparatus  1  via the opening  10   a.    
     The image forming apparatus  1  comprises a developing device forming an image on a printing sheet S supplied via the cassette  2 , a toner device supplying the toner to the developing device, a light scanning device forming an electrostatic latent image on a photosensitive member in the developing device, a fixing device fixing the toner image transferred on the printing sheet S, and a discharging device discharging the printing sheet S on which formation of the image is completed, to the outside of the housing  10 . 
     On the cassette  2 , the printing sheet S may be loaded. The cassette  2  is provided at a lower portion of the housing  10  in the drawable manner to supply the printing sheet S to the developing device. The printing sheet S loaded on the cassette  2  is picked up one by one by a pick-up portion and then transferred to the developing device by a feeding port. 
     The developing device comprises a photosensitive member forming an electrostatic latent image, an agitating screw agitating the toner supplied from the toner device, a developing roller supplying the toner agitated by the agitating screw, to the photosensitive member, and a charging member charging the photosensitive member. The toner supplied from the toner device is supplied to the photosensitive member by the developing roller to form a visible image. The photosensitive member forms a transfer nip (N 1 ) by making contact with a transfer roller so that the toner forming the visible image, which is supplied to the photosensitive member, is transferred to the printing sheet S. 
     The light scanning device forms an electrostatic latent image on the photosensitive member by scanning the light comprising image information to the photosensitive member. The fixing device fixes the toner image, which is formed on the printing sheet S, by applying the heat and pressure, to the printing sheet S. The printing sheet S passed through the fixing device may be discharged to the outside of the housing  10  by the discharging device. 
       FIG. 2  is a view illustrating an automatic mounting apparatus  100  according to an example. 
     In  FIG. 2 , the automatic mounting apparatus  100  comprises a rail assembly  3  and a locking device  4 . The rail assembly  3  may be mounted to an inner wall of the housing  10  in which the cassette  2  is accommodated. The locking device  4  may be mounted to the rail assembly  3 . 
     The rail assembly  3  comprises a rail frame  30  mounted to the inner wall of the housing  10  of the image forming apparatus  1 . A rail portion  31  guiding the movement of the cassette  2  may be provided on one surface of the rail frame  30 . When the cassette  2  is inserted into the housing  10  from the front side to the rear side of the housing  10 , the rail frame  30  may be disposed to allow the rail portion  31  to extend in the front and rear direction. The movement of the cassette  2  may be guided by the rail portion  31  extended in the front and rear direction. The cassette  2  may be inserted into the housing  10  by moving from A direction, which is toward the front side, to B direction, which is toward the rear side. 
     At least one portion of the rail portion  31  placed in the rear side may be inclined so that a rear end portion is formed downward. When it is assumed that the rail portion  31  is divided into a front portion S 1  and a rear portion S 2 , the rear portion S 2  may be gradually lowered from a portion in which the front portion S 1  and the rear portion S 2  are connected, to its end portion. The end portion of the rear portion S 2  of the rail portion  31  is formed to be lower than the front portion S 1 . Therefore, a height difference H 1  is present between the end portion of the rear portion S 2  and the front portion S 1  of the rail portion  31 . This height difference H 1  may be approximately 4.5 mm. The length of the rear portion S 2  may be approximately 25 mm. 
     Since the rear portion S 2  of the rail portion  31  is inclined, the cassette  2  may be inserted into the housing  10  by being guided along the rail portion  31  and accelerated by sliding on the rear portion S 2 . The cassette  2  may be accessed to the locking device  4  by a force greater than the force applied to the cassette  2  due to the thrust. 
     An idle roller  32  may be provided in one side of the rail frame  31  so that the cassette  2  is softly inserted into or pulled out. 
     The locking device  4  may be disposed on the rear side of the rail portion  31 . The locking device  4  may be adjacent to the rear portion S 2  of the rail portion  31 . The cassette  2 , which is moved from the front side A to the rear side B by being guided by the rail portion  31 , may be locked by the locking device  4 . 
       FIG. 3  is a perspective view illustrating the locking device  4  of  FIG. 2  according to an example,  FIG. 4  is a front view illustrating the locking device  4  of  FIG. 2  according to an example, and  FIG. 5  is an exploded-perspective view illustrating the locking device  4  of  FIG. 2  according to an example. 
     Referring to  FIGS. 3 to 5 , according to an example, the locking device  4  may comprise a case  41  mounted to the rail portion  31 , a locking lever  42  movably mounted on the case  41  and an elastic member  43  transferring the elastic force to the locking lever  42 . 
     A first hole  410  extended in the front and rear direction and a second hole  411  provided in the bent shape may be formed in the case  41 . The first hole  410  and the second hole  411  may be spaced apart from each other by a predetermined distance. 
     The second hole  411  may comprise a locking hole  411   a  extended in the vertical direction and a sliding hole  411   b  extended in the front and rear direction. The locking hole  411   a  may be disposed more toward the front side (A direction) than the sliding hole  411   b . The locking hole  411   a  and the sliding hole  411   b  are connected to form a single hole. The locking hole  411   a  may have any shape as long as it is bent downward (D direction) from the sliding hole  411   b  without extending in the vertical direction. The sliding hole  411   b  may be extended in parallel with the first hole  410 . 
     The locking lever  42  may comprise a body  420 , an interference portion  421  bent from one end portion of the body  420 , and a pressing portion  422  bent from the other end portion of the body  420 . The interference portion  421  and the pressing portion  422  may be provided to face upward (C direction). When the automatic mounting apparatus  100  is installed in the housing  10 , the interference portion  421  may be positioned back of the pressing portion  422 . An engaging portion  24  and  25  provided on the side surface of the cassette  2 , as will be illustrated in  FIGS. 9 and 12 , may be placed in an accommodation portion  423  formed by the body  420 , the interference portion  421  and the pressing portion  422 . 
     In the locking lever  42 , a protrusion  424  inserted into the first hole  410  formed in the case  41  may be formed to protrude. The protrusion  424  may move along the first hole  410 . The protrusion  424  may be provided on the side of the interference portion  421 . 
     The locking lever  42  may be provided with a pin insertion hole  425  to which a pin  44  is inserted and mounted. The pin  44  may be inserted into the second hole  411  formed in the case  41  and movable along the second hole  411 . 
     In the above, it has been described that the protrusion  424  provided in the locking lever  42  is inserted into the first hole  410  and the pin  44  mounted to the pin insertion hole  425  is inserted into the second hole  411 . However, instead of the protrusion  424  inserted into the first hole  410 , the pin may be mounted or the protrusion protruding in the locking lever  42  may be moved along the second hole  411 . 
     One side of the elastic member  43  may be fixed to the case  41  and the other side thereof may be fixed to the locking lever  42 . The case  41  may be provided with an elastic member fixing portion  412  on which one side of the elastic member  43  is mounted. The other side of the elastic member  43  may be fixed to the pin  44  mounted on the locking lever  42 . The elastic member  43  may provide the elastic force so that the locking lever  42  moves from the front side A to the rear side B. 
       FIG. 6  is a perspective view illustrating a locking device  5  according to another example,  FIG. 7  is a front view illustrating the locking device  5  of  FIG. 6 , and  FIG. 8  is an exploded-perspective view illustrating the locking device  5  of  FIG. 6 . 
     In  FIGS. 6 to 8 , the locking device  5  may comprise a case  51 , a locking lever  52  and an elastic member  53 . The locking device  5  may comprise a plurality of elastic members. For example, two elastic members may be provided. The two elastic members may be mounted on a link  55  which is pivotally provided. 
     A first hole  510  extended in the front and rear direction and a second hole  511  provided in the bent shape may be formed in the case  51 . The first hole  510  and the second hole  511  may be spaced apart from each other by a predetermined distance. 
     The second hole  511  may comprise a locking hole  511   a  extended in the vertical direction and a sliding hole  511   b  extended in the front and rear direction. The locking hole  511   a  may be disposed more toward the front side (A direction) than the sliding hole  511   b . The locking hole  511   a  and the sliding hole  511   b  are connected to form a single hole. The locking hole  511   a  may have any shape as long as it is bent downward (D direction) from the sliding hole  511   b  without extending in the vertical direction. The sliding hole  511   b  may be extended in parallel with the first hole  510 . 
     The locking lever  52  may comprise a body  520 , an interference portion  521  bent from one end portion of the body  520 , and a pressing portion  522  bent from the other end portion of the body  520 . The interference portion  521  and the pressing portion  522  may be provided to face upward (C direction). When the automatic mounting apparatus  100  is installed in the housing  10 , the interference portion  521  may be positioned back of the pressing portion  522 . The engaging portion  24  and  25  provided in the side surface of the cassette  2  may be placed in an accommodation portion  523  formed by the body  520 , the interference portion  521  and the pressing portion  522 . 
     In the locking lever  52 , a protrusion  524  inserted into the first hole  510  formed in the case  51  may be formed to protrude. The protrusion  524  may be movable along the first hole  510 . The protrusion  524  may be provided on the side of the interference portion  521 . 
     The locking lever  52  may be provided with a pin insertion hole  525  to which a pin  54  is inserted and mounted. The pin  54  may be inserted into the second hole  511  formed in the case  51  and movable along the second hole  511 . 
     In the above, it has been described that the protrusion  524  provided in the locking lever  52  is inserted into the first hole  510  and the pin  54  mounted to the pin insertion hole  525  is inserted into the second hole  511 . However, instead of the protrusion  524  inserted into the first hole  510 , the pin may be mounted, or the protrusion protruding in the locking lever  52  may be moved along the second hole  511 . 
     The elastic members  53  may comprise a first elastic member  531  and the second elastic member  532 . One side of the first elastic member  531  and one side of the second elastic member  532  may be fixed to a single link  55 . The link  55  may be pivotable about a rotation protrusion  512  protruding from the case  51 . 
     The link  55  may comprise a body portion  550  to which the elastic member  53  is mounted, and a rotation protrusion inserting portion  553  formed in the body portion  550  and configured to surround at least one portion of the rotation protrusion  512 . The first elastic member  531  may be fixed to one end portion of the body portion  550  and the second elastic member  532  may be fixed to the other end portion of the body portion  550 . The body portion  550  may be disposed to extend substantially vertically so that the first elastic member  531  is positioned at the upper side of the second elastic member  532 . 
     The other side of the elastic member  531  may be fixed to the locking lever  52 . For example, the first elastic member  531  may be fixed to the pin  54  mounted on the locking lever  52 . The first elastic member  531  may provide the elastic force so that the locking lever  52  moves from the front side (A direction) to the rear side (B direction). 
     The other end of the second elastic member  532  may be mounted to an elastic member fixing portion  513  provided in the case  51 . The elastic member fixing portion  513  may be positioned in the lower side of the second hole  511 . The second elastic member  532  may provide the elastic force to the link  55  in the direction of pulling the other end of the link  55 . The elastic force of the second elastic member  532  is transmitted to the locking lever  52  through the link  55 , and thus the locking lever  52  may be moved from the front side (A direction) to the rear side (B direction) by receiving the elastic force larger than a case in which only the first elastic member  531  is provided. 
       FIG. 9  is a perspective view illustrating the cassette  2  of  FIG. 1  according to an example, and  FIG. 10  is a view illustrating a portion of the cassette of  FIG. 9 . 
     In  FIGS. 9 and 10 , the cassette  2  may be provided with an accommodation portion  200  on which the printing sheet S is loaded. The cassette  2  may comprise a bottom surface  20  and a side surface  22  connected to the bottom surface  20 . The side surfaces  22  may be provided at opposite corners of the bottom surface  20 , respectively. 
     A front cover  21  may be provided in the front side of the cassette  2 . The front cover  21  may be provided with a handle  210 . The user can insert the cassette  2  into or pull the cassette  2  out from the image forming apparatus  1  by holding the handle  210 . The handle  210  may be formed such that a part of the front cover  21  is cut out. 
     The engaging portion  24  interfered with the locking lever  42  and  52  may be provided on the side surface  22 . The engaging portion  24  may be formed in a rib shape protruding from the side surface  22 . The engaging portion  24  may comprise a first engaging portion  241  protruding from the side surface  22 , a second engaging portion  242  protruding from the side surface  22  and being spaced apart from the first engaging portion  241  by a predetermined distance, and a connecting portion  243  connecting one end portion of the first engaging portion  241  to one end portion of the second engaging portion  242 . The connecting portion  243  may be provided to connect the lower end portion of the first engaging portion  241  to the lower end portion of the second engaging portion  242 . The first engaging portion  241  may be positioned ahead of the second engaging portion  242 . 
     An idle roller  23  may be provided on the side surface  22  of the cassette  2 . When the cassette  2  is inserted into or pulled out from the image forming apparatus  1 , the idle roller  23  may be moved along the rail frame  31  in a sliding manner. Since the idle roller  23  is provided to move along the rail frame  31 , the cassette  2  may be softly inserted into or pulled out. The idle roller  23  may be provided on opposite side surfaces of the cassette  2 . 
     Hereinafter, a description is provided to illustrate an operation in which the cassette  2  is mounted automatically. For convenience,  FIGS. 11A to 110  illustrate a case in which the image forming apparatus  1  is provided with the locking device  4  according to an example shown in  FIGS. 3 to 6 . 
       FIGS. 11A to 11C  are views illustrating the operation in which the cassette  2  is mounted automatically according to an example. 
     Referring to  FIGS. 11A to 110 , the cassette  2  may be moved from the front side (A) to the rear side (B) in the sliding manner and then inserted into the inside of the housing  10 . The idle roller  23  provided in the side surface  22  of the cassette  2  may be slid along the rail portion  31 . The engaging portion  24  may be positioned ahead of the idle roller  23  and then moved together with the cassette  2 . 
     When the idle roller  23  reaches to the inclined rear portion S 2  by passing through the front portion S 1  of the rail portion  31  (refer to  FIG. 2 ), the idle roller  23  may be accelerated due to the weight of the cassette  2  and then moved to the locking lever  42  positioned ahead of the rail portion  31 . Before the engaging portion  24  makes contact with the locking lever  42 , the pin  44  may be positioned in the locking hole  411   a  of the second hole  411 . The pin  44  may be positioned lower than the sliding hole  411   b  so that the pressing portion  422  of the locking lever  42  in which the pin  44  is provided is positioned to avoid the interference of the engaging portion  24 . 
     When the cassette  2  is slid, the second engaging portion  242  may be interfered with the interference portion  421  of the locking lever  42 . The pin  44  may move along the locking hole  411   a  and be positioned in the sliding hole  411   b.    
     When the pin  44  is positioned in the sliding hole  411   b , the pin  44  may be moved to the rear side (B) along the sliding hole  411   b  by the elastic force of the elastic member  43 . The locking lever  42  to which the pin  44  is mounted may move in the rear side (B) together with the cassette  2 . The protrusion  424  of the locking lever  42  may slide along the first hole  410  in the front and rear direction. The engaging portion  24  is positioned in the accommodation portion  423  located between the interference portion  421  and the pressing portion  422 . Since the first engaging portion  241  is pressed by the pressing portion  422  of the locking lever  42 , the first engaging portion  241  may be prevented from moving into the rear side as long as the external force is not applied. Accordingly, the cassette  2  may be inserted into and mounted to the housing  10 . 
     When the cassette  2  is inserted into the cassette  2 , the cassette  2  is lowered by a certain height just before being mounted to the housing  10 , since the rear portion S 2  of the rail portion  31  is inclined. Therefore, the cassette  2  may be automatically mounted to the housing  10  by the force generated when the cassette  2  is lowered, and the elastic force of the elastic member  43 . Since the cassette  2  is configured to be automatically mounted by the rail portion  31  having a height difference and by the elastic member  43 , it may be possible to omit the configuration, e.g., a damper, and thus it may be possible to reduce the manufacturing cost of the image forming apparatus  1 . Since the cassette  2  is mounted to the housing  10  by using the weight of the cassette  2 , it may be possible to insert the cassette  2  into the housing  10  with a small force so as to improve the user experience. 
     A user may pull out the cassette  2  from the housing  10  at the front side (A). The first engaging portion  241  may press the pressing portion  422  of the locking lever  42 , and the cassette  2  together with the locking lever  42  may be slid into the front side (A). The pin  44  may be moved along the sliding hole  411   b , and when the pin  44  reaches the locking hole  411   a , the pin  44  may be moved into the locking hole  411   a . When the pin  44  is moved into the locking hole  411   a , the pressure applied to the first engaging portion  241  by the pressing portion  422  of the locking lever  42  may be released. When the first engaging portion  241  is released, the cassette  2  may be pulled out from the front side. During this operation, the idle roller  23  may be slid along the rail portion  31 . 
       FIG. 12  is a view illustrating a portion of the cassette  2  according to another example. 
     In  FIG. 12 , an engaging portion  25  provided in the cassette  2  has a shape different from the shape of the engaging portion  24  as illustrated in  FIGS. 9 and 10 . The engaging portion  25  may be provided in a substantially W shape. The engaging portion  25  may protrude from the side surface of the cassette  2 . 
     The engaging portion  25  may comprise a first engaging portion  253  and a second engaging portion  256 , wherein the first engaging portion  253  and the second engaging portion  256  protrude on the side surface of the cassette  2  and spaced apart from each other by a predetermined distance. The first engaging portion  253  may be positioned ahead of the second engaging portion  256 . The first engaging portion  253  and the second engaging portion  256  may be connected by connecting portions. 
     The connecting portions may comprise a first connecting portion  254  extending from the lower end of the first engaging portion  253  to the rear upper portion, a second connecting portion  255  extending from the lower end of the second engaging portion  256  to the front upper portion, and a third connecting portion  250  connecting the first connecting portion  254  to the second connecting portion  255 . As needed, the third connecting portion  250  may be omitted and thus the first connecting portion  254  and the second connecting portion  255  may be directly connected to each other. 
     By the shape of the connecting portion  250 ,  254  and  255 , the engaging portion  25  may comprise a first concave portion  251  formed by the first engaging portion  253  and the first connecting portion  254 , and a second concave portion  252  formed by the second engaging portion  256  and the second connecting portion  255 . The second engaging portion  256  may be provided with an inclined surface  256   a . The inclined surface  256   a  may be provided to extend from the rear upper side to the front lower side. 
     Hereinafter a description is provided to illustrate an operation in which the cassette  2  of  FIG. 12  is mounted automatically in accordance with another example.  FIGS. 13A to 14D  illustrate the cassette  2  of  FIG. 12  inserted into or pulled out from the image forming apparatus  1  to which the locking device  4  shown in  FIGS. 7 and 8  is applied. 
       FIGS. 13A to 13C  are views illustrating the operation in which the cassette  2  of  FIG. 12  is mounted automatically according to another example. In  FIGS. 13A to 13C , when the cassette  2  is inserted into or pulled out from the housing  10  normally, the cassette  2  may be operated in a way similar with the cassette  2  as illustrated in  FIGS. 11A to 11C . 
     Particularly, the cassette  2  may be moved from the front side (A) to the rear side (B) in the sliding manner and then inserted into the inside of the housing  10 . The idle roller  23  provided in the side surface  22  of the cassette  2  may be slid along the rail portion  31 . The engaging portion  25  may be positioned ahead of the idle roller  23  and then moved together with the cassette  2 . 
     When the idle roller  23  reaches to the inclined rear portion S 2  by passing through the front portion S 1  of the rail portion  31  (refer to  FIG. 2 ), the idle roller  23  may be accelerated due to the weight of the cassette  2  and then moved to the locking lever  52  positioned ahead of the rail portion  31 . Before the engaging portion  25  makes contact with the locking lever  52 , the pin  54  may be positioned in the locking hole  511   a  of the second hole  511 . The pin  54  may be positioned lower than the sliding hole  511   b  so that the pressing portion  522  of the locking lever  52  in which the pin  54  is provided is positioned to avoid the interference of the engaging portion  25 . 
     When the cassette  2  is slid, the second engaging portion  256  may be interfered with the interference portion  521  of the locking lever  52 . The pin  54  may move along the locking hole  511   a  and be positioned in the sliding hole  511   b.    
     When the pin  54  is positioned in the sliding hole  511   b , the pin  54  may be moved to the rear side (B) along the sliding hole  511   b  by the elastic force of the elastic member  53 . The locking lever  52  to which the pin  54  is mounted may move in the rear side (B) together with the cassette  2 . The protrusion  524  of the locking lever  52  may slide along the first hole  510  in the front and rear direction. The engaging portion  25  is positioned in the accommodation portion  523  located between the interference portion  521  and the pressing portion  522 . Since the first engaging portion  253  is pressed by the pressing portion  522  of the locking lever  52 , the first engaging portion  253  may be prevented from moving in the rear side as long as the external force is not applied. Accordingly, the cassette  2  may be inserted and mounted to the housing  10 . 
     When the cassette  2  is inserted, the cassette  2  is lowered by a certain height just before being mounted to the housing  10 , because the rear portion S 2  of the rail portion  31  is inclined. Therefore, the cassette  2  may be automatically mounted to the housing  10  by the force generated when the cassette  2  is lowered, as well as by the elastic force of the elastic member  53 . Since the cassette  2  is configured to be automatically mounted by the rail portion  31  having a height difference and by the elastic member  53 , it may be possible to omit the configuration, e.g., a damper, and thus it may be possible to reduce the manufacturing cost of the image forming apparatus  1 . Since the cassette  2  is mounted to the housing  10  by using the weight of the cassette  2 , it may be possible to insert the cassette  2  into the housing  10  with a small force so as to improve the user experience. 
     The user may pull out the cassette  2  from the housing  10  at the front side (A). The first engaging portion  253  may press the pressing portion  522  of the locking lever  52 , and the cassette  2  together with the locking lever  52  may be slid in the front side (A). The pin  54  may be moved along the sliding hole  511   b , and when the pin  54  reaches the locking hole  511   a , the pin  54  may be moved to the locking hole  511   a . When the pin  54  is moved to the locking hole  511   a , the pressure applied to the first engaging portion  253  by the pressing portion  522  of the locking lever  52  may be released. When the first engaging portion  253  in the pressed condition is released, the cassette  2  may be pulled out at the front side. In this time, the idle roller  23  may be slid along the rail portion  31 . 
       FIG. 14A to 14D  are views illustrating an operation when the cassette is erroneously mounted according to another example. In  FIGS. 14A to 14D , it will be illustrated that the cassette  2  is inserted into the housing  10  in a state in which the pin  54  is positioned in the sliding hole  511   b  of the second hole  511 . In the normal state, the cassette  2  is inserted into the housing  10  in a state in which the pin  54  is positioned in the locking hole  511   a  of the second hole  511 . However, the pin  54  may be escaped from the locking hole  511   a  and then positioned in the sliding hole  511   b  due to various causes generated during the manufacturing, transportation or use. In this case, when the cassette  2  is inserted into the housing  10 , it may be impossible to perform the operation as shown  FIGS. 13A to 13C . 
     In a state in which the cassette  2  is provided with the engaging portion  24  of  FIG. 10 , when the cassette is inserted into the housing in as state in which the pin  54  is positioned in the sliding hole  511   b  before the above mentioned cassette is inserted into the housing  10 , the second engaging portion  242  may be interfered with the interference portion  521  of the locking lever  52  and thus the cassette  2  is prevented from inserting into the rear side any longer. A portion of the front portion of the cassette  2  is protruded to the outside of the housing  10 , and thus the cassette  2  is not fully mounted. 
     When the cassette  2  is provided with the engaging portion  25  of  FIG. 12 , the second engaging portion  256  may pass through the interference portion  521  of the locking lever  52  by the inclined surface  256   a  provided in the second engaging portion  256 . The first connecting portion  254  may be interfered with the interference portion  521  after the second engaging portion  256  passes through the interference portion  521 , and thus the cassette  2  is prevented from being inserted into the front side any longer. 
     In a state in which the second engaging portion  256  is passed through the interference portion  521 , when a user pulls the cassette  2  out, the interference portion  521  may be interfered with the second connecting portion  255  and the locking lever  52  may be moved together with the cassette  2  in the front side. The pin  54  may be moved along the sliding hole  511   b  in the front side and then the pin  54  may be inserted into the locking hole  511   a  by passing through the sliding hole  511   b . When the pin  54  is inserted into the locking hole  511   a , it becomes the state in which the cassette  2  is mounted normally, and thus a user can properly mount the cassette  2  to the housing  10 . Therefore, the cassette  2  may be mounted to the housing  10  properly, as illustrated in  FIGS. 13A to 13C . 
     According to the conventional manner, when the pin  54  is positioned in the sliding hole  511   b  without being in the locking hole  511   a , it may be required that a portion of the image forming apparatus  1  is disassembled or the pin  54  is positioned to the locking hole  511   a  after turning over the image forming apparatus  1  so that the cassette  2  is mounted properly. 
     However, according to the present disclosure, without disassembling the image forming apparatus  1  or directly adjusting the position of the pin  54  after turning over the image forming apparatus  1 , the pin  54  may be positioned in the locking hole  511   a  by an operation in which the cassette  2  is inserted or pulled by the engaging portion  25  as illustrated in  FIG. 12 . Therefore, the cassette can be quickly mounted properly, and the user&#39;s convenience may be improved since an additional repair work is not required. 
       FIG. 15  is a view illustrating a configuration of a printing sheet outlet portion of the cassette according to an example, and  FIG. 16  is a cross-sectional view illustrating the printing sheet outlet portion of the cassette according to an example. 
     Referring to  FIGS. 15 and 16 , according to an example, a printing sheet outlet portion  12  to which the printing sheet S loaded in the cassette  2  is discharged may be positioned in the front side of the accommodation portion  200 . The printing sheet S may be guided to move to the upper side by the printing sheet outlet portion  12 . The printing sheet outlet portion  12  may be further provided with an outlet portion guide  11 . The outlet portion guide  11  may be mounted to one side of the inside of the housing  10 . The outlet portion guide  11  may be pivotable with respect to a rotary shaft  110 . The rotary shaft  110  may be formed in the injection-molded integrally with the outlet portion guide  11 . 
     According to the conventional manner, the outlet portion guide may be fixed to the inside of the housing. When the outlet portion guide is fixed, the cassette  2  may be interfered with the outlet portion guide  11  when the rail portion guiding the movement of the cassette  2  is inclined. 
     According to the present disclosure, when a portion of the rear portion of the rail portion  31  is inclined so that the cassette  2  is lowered just before the cassette  2  is mounted, the cassette  2  may be easily inserted into or pulled out without being interfered with the outlet portion guide  11  since the outlet portion guide  11  is pivotable with respect to the rotary shaft  110  as illustrated in  FIGS. 15 and 16 . In addition, the outlet portion guide  11  and the printing sheet outlet portion  12  of the cassette  2  are configured not to be apart from each other as far as possible, and thus the printing sheet S discharged via the outlet portion guide  11  may be prevented from being bent or entering between the outlet portion guide  11  and the printing sheet outlet portion  12 . 
     It may be possible to easily mount or detach the cassette  2 , which is configured to be inserted into or pulled out from the image forming apparatus  1 , by the automatic mounting apparatus  100  having the rail assembly  3  and the locking device  4  and  5 . By omitting the configuration, e.g., a damper, it may be possible to reduce the manufacturing cost. When mounting the cassette  2  by the automatic mounting apparatus  100 , it may be possible to prevent the impact or noise. Although the locking lever is in the position which causes a malfunction, it may possible to position the locking lever to the proper operation state without any inconvenient works, e.g., disassembling the components. 
     Although a few examples of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these examples without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.