Patent Publication Number: US-2022221818-A1

Title: Connection structure between a door for replacing a waste toner container and a print medium cassette

Description:
BACKGROUND 
     An image forming apparatus using an electrophotographic method forms a visible toner image on a photoconductor by supplying toner to an electrostatic latent image formed on the photoconductor, transfers the toner image to a print medium, fixes the transferred toner image to the print medium, and prints an image on the print medium. A developing device contains toner and supplies the toner to the electrostatic latent image formed on the photoconductor to form the visible toner image on the photoconductor. 
     Waste toner produced during an image forming process is contained in a waste toner container. The waste toner container may be removed from the image forming apparatus, such as when the waste toner container is filled with waste toner, and a new waste toner container may be mounted therein. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Various examples will be described below by referring to the following figures. 
         FIG. 1  is a view schematically illustrating an electrophotographic image forming apparatus according to an example. 
         FIG. 2  is a perspective view illustrating an external appearance of the electrophotographic image forming apparatus shown in  FIG. 1  according to an example. 
         FIG. 3  is a schematic perspective view illustrating a replacement structure for a waste toner container according to an example. 
         FIG. 4  is a schematic bottom perspective view illustrating the replacement structure for the waste toner container shown in  FIG. 3  according to an example. 
         FIG. 5  is a schematic bottom perspective view illustrating a print medium cassette in a withdrawn position in the replacement structure for the waste toner container shown in  FIGS. 3 and 4  according to an example. 
         FIG. 6  is a schematic bottom perspective view illustrating a print medium cassette in a mounted position in the replacement structure for the waste toner container shown in  FIGS. 3 and 4  according to an example. 
         FIG. 7  is a view schematically illustrating an electrophotographic image forming apparatus according to an example. 
         FIG. 8  is a perspective view illustrating an external appearance of the electrophotographic image forming apparatus shown in  FIG. 7  according to an example. 
         FIG. 9  is a schematic perspective view illustrating a replacement structure for a waste toner container applied to the image forming apparatus shown in  FIG. 7  according to an example. 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLES 
     Hereinafter, various examples will be described with reference to the drawings. Like reference numerals in the specification and the drawings denote like elements, and thus a redundant description may be omitted. 
       FIG. 1  is a view schematically illustrating an electrophotographic image forming apparatus according to an example.  FIG. 2  is a perspective view illustrating an external appearance of the electrophotographic image forming apparatus shown in  FIG. 1  according to an example. 
     Referring to  FIGS. 1 and 2 , the electrophotographic image forming apparatus includes a main body  1  and a print medium cassette  90  that may be loaded with a print medium P to be fed into the main body  1 . The main body  1  may include a printing unit  2 , a waste toner container  30  to contain waste toner discharged from the printing unit  2 , and a door  3  that may be opened or closed to replace the waste toner container  30 . The print medium cassette  90  may be provided under the main body  1  to move between a mounted position ( FIG. 1 ) in which the print medium cassette  90  is pushed into the main body  1  and a withdrawn position ( FIG. 2 ) in which the print medium cassette  90  is pulled out from the main body  1 . The print medium P may be loaded in the print medium cassette  90  in the withdrawn position. 
     The printing unit  2  may print a color image on the print medium P by using an electrophotographic method. The printing unit  2  may include a plurality of developing devices  10 , an exposure unit  50 , a transfer unit, and a fusing unit  80 . The printing unit  2  may further include a plurality of toner cartridges  20 , respectively connected to the plurality of developing devices  10 , to contain a developer and to supply the developer to the plurality of developing devices  10 , respectively. The plurality of toner cartridges  20  and the plurality of developing devices  10  may be detachably connected to the main body  1  and may be replaced independently. 
     In an example, the plurality of developing devices  10  may include a plurality of developing devices  10 C,  10 M,  10 Y, and  10 K for forming toner images of cyan (C), magenta (M), yellow (Y), and black (K) colors. The plurality of toner cartridges  20  may include a plurality of toner cartridges  20 C,  20 M,  20 Y, and  20 K respectively containing toners of cyan (C), magenta (M), yellow (Y), and black (K) colors to be supplied to the plurality of developing devices  10 C,  10 M,  10 Y, and  10 K, respectively. Hereinafter, reference numerals with letters C, M, Y, and K respectively denote elements for forming C, M, Y, and K images unless otherwise stated. 
     Each of the developing devices  10  may include a photosensitive drum  14  on which an electrostatic latent image may be formed, and a developing roller  13  to develop the electrostatic latent image into a visible toner image by supplying toner to the electrostatic latent image. The photosensitive drum  14  is an example of a photoconductor on which an electrostatic latent image may be formed and may include a conductive metal pipe and a photosensitive layer formed on an outer circumferential surface thereof. A charging roller  15  is a charger for charging the surface of the photosensitive drum  14  to a uniform electric potential. A charging brush or a corona charger may also be used instead of the charging roller  15 . 
     The exposure unit  50  emits light, which is modulated to correspond to image information, to the photosensitive drum  14  and forms an electrostatic latent image on the photosensitive drum  14 . A laser scanning unit using a laser diode as a light source or a light-emitting diode (LED) exposure unit using an LED as a light source may be used as the exposure unit  50 . 
     The developing roller  13  is spaced apart from the photosensitive drum  14 . An interval between an outer circumferential surface of the developing roller  13  and an outer circumferential surface of the photosensitive drum  14  may be, for example, tens of to hundreds of microns. The developing roller  13  may have a form in which a magnetic member is located in a rotating developing sleeve. In the developing device  10 , toner may be mixed with a magnetic carrier, and the toner is attached to the surface of the magnetic carrier. The magnetic carrier is attached to the surface of the developing roller  13  to be transported to a developing region where the photosensitive drum  14  faces the developing roller  13 . A regulating member (not shown) regulates an amount of toner and carrier transported to the developing region. Only toner is to be supplied to the photosensitive drum  14  by a development bias voltage applied between the developing roller  13  and the photosensitive drum  14  to develop an electrostatic latent image formed on the photosensitive drum  14  into a visible toner image. 
     The transfer unit transfers the toner image formed on the photosensitive drum  14  to the print medium P. For example, the transfer unit may include an intermediate transfer belt  60 , an intermediate transfer roller  61 , and a transfer roller  70 . The intermediate transfer belt  60  temporarily receives toner images developed on the photosensitive drums  14  of the plurality of developing devices  10 C,  10 M,  10 Y, and  10 K. A plurality of intermediate transfer rollers  61  are located to face the photosensitive drums  14  of the plurality of developing devices  10 C,  10 M,  10 Y, and  10 K with the intermediate transfer belt  60  therebetween. An intermediate transfer bias voltage for intermediate-transferring the toner images developed on the photosensitive drum  14  to the intermediate transfer belt  60  is applied to the plurality of intermediate transfer rollers  61 . The transfer roller  70  is located to face the intermediate transfer belt  60 . The print medium P output from the print medium cassette  90  is transported along a feed path  91  between the transfer roller  70  and the intermediate transfer belt  60 . A transfer bias voltage for transferring the toner images intermediately transferred to the intermediate transfer belt  60  to the print medium P is applied to the transfer roller  70 . 
     The fusing unit  80  fixes the toner images transferred to the print medium P onto the print medium P by applying heat and/or pressure to the toner images. A shape of the fusing unit  80  is not limited to that shown in  FIG. 1 . The print medium P having the image is discharged to the outside of the main body  1  by a discharge roller  92 . 
     Toner or foreign material remaining on the surface of the photosensitive drum  14  may be removed by a cleaning member  17  after the intermediate transfer process. After the transfer process, toner or foreign material remaining on the surface of the intermediate transfer belt  60  may be removed by a cleaning member  62 . When an auto developer refill (ADR) method is used, the toner cartridge  20  may also include a small amount of a carrier as well as the toner, and the toner and the carrier are supplied to the developing device  10 . In order to maintain a desired amount of the developer (toner and carrier) contained in the developing device  10 , an excess of the developer may be discharged from the developing device  10 . The toner and the foreign material removed from the photosensitive drum  14  and the intermediate transfer belt  60  and the excess developer discharged from the developing device  10  are referred to as ‘waste toner’. The waste toner may be transported to the waste toner container  30  by a transfer unit (not shown) and contained in the waste toner container  30 . 
     As indicated by dashed lines in  FIGS. 1 and 2 , an intermediate container  40  may be interposed between the printing unit  2  and the waste toner container  30 . The intermediate container  40  may temporarily contain waste toner discharged from the printing unit  2 . The intermediate container  40  may have five inlets  43  through which waste toner respectively removed from the four photosensitive drums  14  and waster toner removed from the intermediate transfer belt  60  is introduced. The intermediate container  40  may have a waste toner outlet  41 . The waste toner container  30  may have a waste toner inlet  31 . The waste toner outlet  41  is connected to the waste toner inlet  31 . Although not shown in the drawings, each of the waste toner outlet  41  and the waste toner inlet  31  may be provided with a shutter for opening or closing thereof. The shutter may open the waste toner outlet  41  and the waste toner inlet  31  based on an operation of mounting the waste toner container  30  in the main body  1  and may close the waste toner outlet  41  and the waste toner inlet  31  when the waste toner container  30  is removed from main body  1 . The intermediate container  40  may be provided with a transport member  42  to transport the waste toner into the waste toner container  30 . The transport member  42  may include an auger that transports the waste toner to the waste toner outlet  41 . In this structure, the waste toner that has been discharged from the printing unit  2  and contained in the intermediate container  40  may be transported to the waste toner outlet  41  by the transport member  42  and stored in the waste toner container  30  through the waste toner inlet  31 . A connection pipe (not shown) may be disposed between the intermediate container  40  and the waste toner container  30 . Each of the waste toner outlet  41  and the waste toner inlet  31  may be connected to the connection pipe. 
     The waste toner container  30  may be replaceable. For example, when the waste toner container  30  is filled with waste toner, the waste toner container  30  may be removed from the main body  1 , and a new waste toner container  30  may be mounted in the main body  1 . 
     As shown in  FIGS. 1 and 2 , the waste toner container  30  is provided in the main body  1 . The waste toner container  30  is exposed to the outside by opening a portion of the main body  1  by opening (e.g., rotating) the door  3 . In the state in which the door  3  is opened, the waste toner container  30  may be removed from the main body  1  by sliding the waste toner container  30 , and a new waste toner container  30  may be mounted in the main body  1 . 
     The print medium cassette  90  is provided under the main body  1  and may be pulled out. The print medium cassette  90  is located under the waste toner container  30 . The print medium cassette  90  may move to the withdrawn position as shown in  FIG. 2  to load the print medium P therein. After loading the print medium P, the print medium cassette  90  may slide in a direction opposite to the direction when the print medium cassette  90  is pulled out to move to the mounted position. 
     A portion of the waste toner container  30 , such as a portion of the waste toner container  30  adjacent to the waste toner inlet  31 , may be contaminated by waste toner. During a process of removing the waste toner container  30 , waste toner may fall from the waste toner container  30 . When the waste toner container  30  is removed from the main body  1  in a state in which the print medium cassette  90  is in the withdrawn position, the inside of the print medium cassette  90  and the print medium P loaded in the print medium cassette  90  may be contaminated by waste toner falling from the waste toner container  30 . When the print medium cassette  90  is moved to the mounted position in this state, the inside of the main body  1  may be contaminated by waste toner. In addition, when the contaminated print medium P is transported along the feed path  91 , the feed path  91  may be contaminated by waste toner. 
     An image forming apparatus according to the example has a replacement structure for the waste toner container  30  which inhibits the door  3  from being opened in a state in which the print medium cassette  90  is in the withdrawn position and allows the door  3  to be opened in conjunction with the movement of the print medium cassette  90  from the withdrawn position to the mounted position. Hereinafter, examples of a replacement structure for the waste toner container  30  will be described. 
       FIG. 3  is a schematic perspective view illustrating a replacement structure for a waste toner container according to an example.  FIG. 4  is a schematic bottom perspective view illustrating the replacement structure for the waste toner container shown in  FIG. 3  according to an example.  FIG. 5  is a schematic bottom perspective view illustrating a print medium cassette in a withdrawn position in the replacement structure for the waste toner container shown in  FIGS. 3 and 4  according to an example.  FIG. 6  is a schematic bottom perspective view illustrating a print medium cassette in a mounted position in the replacement structure for the waste toner container shown in  FIGS. 3 and 4  according to an example. In  FIG. 4 , the print medium cassette  90  is omitted for sake of clarity. In  FIGS. 5 and 6 , the print medium cassette  90  is marked as two-dot chain lines. 
     Referring to  FIGS. 3 to 6 , an opening lever  300  and a locking member  600  are shown. The opening lever  300  may move between a first position (marked as a solid line in  FIG. 4 ), in which the door  3  is locked in a closed position, and a second position (marked as dashed lines in  FIG. 4 ) in which the opening of the door  3  is allowed. The locking member  600  may move between a locking position (marked as dashed lines in  FIG. 4 ) in which the opening lever  300  is locked in the first position and a releasing position (marked as a solid line in  FIG. 4 ) in which the locking of the opening lever  300  is released in conjunction with the movement of the print medium cassette  90  from the withdrawn position to the mounted position thereof. An elastic member  700  applies an elastic force to the locking member  600  in a direction toward the locking position. 
     Referring to  FIG. 4 , the opening lever  300  may be provided at the door  3  to slide between the first position and the second position. The opening lever  300  may include a pressing portion  310  exposed to the outside of the door  3  to operate the opening lever  300  from the outside and a first holding portion  321  to be caught by a second holding portion  511  provided at the main body  1  in the first position to prevent the door  3  from being opened. In an example, the opening lever  300  slides in a direction perpendicular to a pulling direction A 1  of the print medium cassette  90  to move between the first position and the second position. The opening lever  300  may be elastically biased by a spring (not shown) to slide to the first position. A user may move the opening lever  300  from the first position to the second position by sliding the opening lever  300  in a direction opposite to an elastic force of the spring by pressing the pressing portion  310 . When the pressure applied to the pressing portion  310  is removed, the opening lever  300  may return to the first position from the second position by the elastic force of the spring. The spring may be implemented in various forms such as a coil spring, a leaf spring, etc. and may also be implemented in the form of an elastic arm integrated with the opening lever  300 . 
     The main body  1  may be provided with a support frame  5  that supports the waste toner container  30  in a manner allowing the waste toner container  30  to slide. The second holding portion  511  may be provided at the support frame  5 . The locking member  600  may be supported by the support frame  5  to slide between the locking position and the releasing position. The locking member  600  may be supported under the support frame  5  to slide in the sliding directions A 1  and A 2  of the print medium cassette  90 . According to an example, the elastic member  700  may be implemented by a tension coil spring, one end of which is connected to the locking member  600  and the other end of which is connected to the support frame  5 . 
     The locking member  600  may include a locking portion  610  to be caught by the opening lever  300  at the locking position to lock the opening lever  300 , and a releasing portion  620  to interfere with the print medium cassette  90  and move to the releasing position when the print medium cassette  90  slides to the mounted position from the withdrawn position. The locking member  600  may slide in the pulling direction A 1  to move to the locking position and slide in the mounting direction A 2  to move to the releasing position. 
     Referring to  FIG. 4 , the locking portion  610  may be in the form of a protrusion protruding from the locking member  600  in the pulling direction A 1 . At the locking position, the locking portion  610  may interfere with the first holding portion  321 . As marked with dashed lines in  FIG. 4 , when the locking member  600  is in the locking position, the locking portion  610  is located adjacent to the second position of the first holding portion  321  of the opening lever  300 . In this state, the first holding portion  321  is blocked by the locking portion  610  and cannot move to the second position although the pressing portion  310  is pressed. Thus, the opening lever  300  is locked in the first position and the door  3  cannot be opened. When the locking member  600  is in the locking position, a first stopper  630  provided at the locking member  600  is brought into contact with a second stopper  520  provided at the support frame  5 . Thus, the locking member  600  may be maintained at the locking position although the elastic force of the elastic member  700  is applied thereto. 
     As marked as the solid line in  FIG. 4 , when the locking member  600  is in the releasing position, the locking portion  610  is spaced apart from the first holding portion  321  in the mounting direction A 2 , and the opening lever  300  is in a state capable of moving to the second position. When the pressing portion  310  is pressed, the opening lever  300  moves to the second position, thereby releasing the first holding portion  321  from the second holding portion  511 . The door  3  is in a state to be opened. 
     The print medium cassette  90  is located under the main body  1 , i.e., under the support frame  5 . The releasing portion  620  may be in the form of a protrusion extending from the locking member  600  downward toward the print medium cassette  90  to interfere with the print medium cassette  90  that slides to the mounted position from the withdrawn position. Referring to  FIGS. 2, 5, and 6 , the print medium cassette  90  includes an interfering portion  99  interfering with the releasing portion  620 . When the print medium cassette  90  is in the withdrawn position, the interfering portion  99  is spaced apart from the releasing portion  620  and the locking member  600  is maintained at the locking position by the elastic force of the elastic member  700 . When the print medium cassette  90  slides in the mounting direction A 2  from the withdrawn position, the interfering portion  99  pushes the releasing portion  620  to move the locking member  600  in a direction opposite to the elastic force of the elastic member  700  to move to the releasing position. 
     Hereinafter, a process of replacing the waste toner container  30  will be described with reference to  FIGS. 1 to 6 . 
     Referring to  FIG. 6 , the print medium cassette  90  is in the mounted position and the door  3  is closed. The opening lever  300  is located in the first position. Because the first holding portion  321  is caught by the second holding portion  511 , the door  3  is maintained in the closed state. Because the interfering portion  99  of the print medium cassette  90  is in contact with the releasing portion  620  of the locking member  600 , the locking member  600  is maintained at the releasing position although the elastic force of the elastic member  700  is applied thereto. The locking portion  610  is spaced apart from the first holding portion  321  in the mounting direction A 2 . When the pressing portion  310  is pressed, the first holding portion  321  is released from the second holding portion  511  and the opening lever  300  moves to the second position. Thus, by opening the door  3  and sliding the waste toner container  30  in the pulling direction A 1  as shown in  FIG. 2 , the waste toner container  30  may be removed from the main body  1 . A new waste toner container  30  may be mounted in the main body  1  by sliding the new waste toner container  30  in the mounting direction A 2 . By closing the door  3 , the first holding portion  321  is caught by the second holding portion  511  and the door  3  may be maintained in the closed state. 
     The print medium cassette  90  may move to the withdrawn position by sliding the print medium cassette  90  in the pulling direction A 1  to load the print medium P in the print medium cassette  90 . As the print medium cassette  90  slides in the pulling direction A 1 , the locking member  600  slides in the pulling direction A 1  by the elastic force of the elastic member  700  to move to the locking position. As shown in  FIG. 5 , when the locking member  600  arrives at the locking position, the first stopper  630  is brought into contact with the second stopper  520  and the locking member  600  is maintained at the locking position. The locking portion  610  is located at a position adjacent to the second position of the first holding portion  321 . In this state, the first holding portion  321  is blocked by the locking portion  610 , and thus the first holding portion  321  cannot move to the second position although the pressing portion  310  is pressed. Thus, the opening lever  300  is locked in the first position and the door  3  cannot be opened. 
     After loading the print medium P in the print medium cassette  90 , the print medium cassette  90  may slide and move in the mounting direction A 2  to the mounted position. When the print medium cassette  90  slides in the mounting direction A 2  to some extent, the interfering portion  99  of the print medium cassette  90  is brought into contact with the releasing portion  620  of the locking member  600 . When the print medium cassette  90  continues sliding in the mounting direction A 2  in this state, the locking member  600  is pushed by the print medium cassette  90  to slide in the direction opposite to the elastic force of the elastic member  700 , i.e., in the mounting direction A 2 . The locking portion  610  is spaced apart from the first holding portion  321  in the mounting direction A 2 . When the print medium cassette  90  arrives at the mounted position as shown in  FIG. 6 , the locking member  600  arrives at the releasing position and the opening lever  300  is in a state capable of moving from the first position to the second position, and thus the waste toner container  30  may be replaced. 
     As described above, because the door  3  cannot be opened when the print medium cassette  90  is in the withdrawn position, the waste toner container  30  cannot be removed. Thus, an amount of contamination of the inside of the print medium cassette  90  caused by waste toner leaked during the process of replacing the waste toner container  30  may be reduced. 
       FIG. 7  is a view schematically illustrating an electrophotographic image forming apparatus according to an example.  FIG. 8  is a perspective view illustrating an external appearance of the electrophotographic image forming apparatus shown in  FIG. 7  according to an example. 
     The example of the image forming apparatus shown in  FIGS. 7 and 8  is different from the image forming apparatus shown in  FIGS. 1 and 2 , in that the image forming apparatus shown in  FIGS. 7 and 8  includes two print medium cassettes  90 - 1  and  90 - 2  and the opening of the door  3  is selectively allowed according to a position of the print medium cassette  90 - 2 . Hereinafter, an example of the image forming apparatus shown in  FIGS. 7 and 8  will be described based on differences from the example of the image forming apparatus shown in  FIGS. 1 and 2 . In the following description, the same or like elements are denoted by the same or like reference numerals, and a duplicate description will be omitted. 
     Referring to  FIGS. 7 and 8 , the image forming apparatus includes a main body  1  and a print medium cassette  90  that may be loaded with a print medium P to be fed into the main body  1 . The print medium cassette  90  is movable between a mounted position in which the print medium cassette  90  is pushed into the main body  1  and a withdrawn position in which the print medium cassette  90  is pulled out from the main body  1 . The main body  1  may include a printing unit  2 , a waste toner container  30  to contain waste toner discharged from the printing unit  2 , and a door  3  opened or closed for replacing the waste toner container  30 . The printing unit  2  may print a color image on the print medium P by using an electrophotographic method. Because the printing unit  2  is the same as that described above with reference to  FIG. 1 , a duplicate description will be omitted. 
     The print medium cassette  90  may include a first print medium cassette  90 - 1  and a second print medium cassette  90 - 2 . The first print medium cassette  90 - 1  is located under the main body  1 . The second print medium cassette  90 - 2  is located under the first print medium cassette  90 - 1 . The first print medium cassette  90 - 1  and the second print medium cassette  90 - 2  may independently slide both in the pulling direction A 1  and the mounting direction A 2  moving to the withdrawn position and the mounted position respectively to load the print medium P. The print medium P output from the second print medium cassette  90 - 2  is guided to the feed path  91  through a second feed path  91   a . The second feed path  91   a  may be provided with at least one roller to transport the print medium P. 
     The waste toner produced from the printing unit  2  is stored in the waste toner container  30  as described above. As marked with dashed lines in  FIGS. 7 and 8 , an intermediate container  40  may be interposed between the printing unit  2  and the waste toner container  30 . The intermediate container  40  may include a transport member  42  to transport waste toner to the waste toner container  30 . A connection pipe  45  may be located between the intermediate container  40  and the waste toner container  30 . Each of the waste toner outlet  41  and the waste toner inlet  31  may be connected to the connection pipe  45 . The waste toner outlet  41  is connected to the waste toner inlet  31  via the connection pipe  45 . 
     Referring to  FIG. 8 , the waste toner container  30  and the door  3  are located on a lateral side of the first print medium cassette  90 - 1 . Thus, when the waste toner container  30  is replaced while the first print medium cassette  90 - 1  is open, the inside of the first print medium cassette  90 - 1  is less likely to be contaminated by waste toner. According to an example, the waste toner container  30  is located above the second print medium cassette  90 - 2 . When the waste toner container  30  is removed from the main body  1  while the second print medium cassette  90 - 2  is in the withdrawn position, the inside of the second print medium cassette  90 - 2  and the print medium P loaded in the second print medium cassette  90 - 2  may be contaminated by waste toner falling from the waste toner container  30 . 
     To address these problems, an image forming apparatus according to an example has a replacement structure for the waste toner container  30  which inhibits the door  3  from being opened when the second print medium cassette  90 - 2  is in the withdrawn position and allows the door  3  to be opened in conjunction with an operation of movement of the second print medium cassette  90 - 2  from the withdrawn position to the mounted position. 
       FIG. 9  is a schematic perspective view illustrating a replacement structure for a waste toner container applied to the image forming apparatus shown in  FIG. 7  according to an example. The replacement structure for the waste toner container  30  illustrated in  FIG. 9  may be identical to that illustrated in  FIGS. 4 to 6 . In this case,  FIG. 4  is a bottom perspective view from which the second print medium cassette  90 - 2  of  FIG. 9  is omitted. The print medium cassette  90  shown in  FIGS. 5 and 6  may be considered the second print medium cassette  90 - 2  as marked in parenthesis. 
     The structures of the opening lever  300 , the locking member  600 , and the elastic member  700  are as defined above with reference to  FIG. 4 . However, the locking member  600  may move between a locking position, in which the opening lever  300  is locked in the first position, and a releasing position in which the locking of the opening lever  300  is released in conjunction with the movement of the second print medium cassette  90 - 2  from the withdrawn position to the mounted position. In addition, the second print medium cassette  90 - 2  includes an interfering portion  99  that pushes the locking member  600  to the release position from the locking position. 
     Hereinafter, a process of replacing the waste toner container  30  will be briefly described with reference to  FIGS. 5 to 9 . 
     Referring to  FIG. 6 , the second print medium cassette  90 - 2  is in the mounted position. Because the opening lever  300  is located in the first position and the first holding portion  321  is caught by the second holding portion  511 , the door  3  is maintained in the closed state. Because the interfering portion  99  of the second print medium cassette  90 - 2  is in contact with the releasing portion  620  of the locking member  600 , the locking member  600  is maintained at the releasing position although the elastic force of the elastic member  700  is applied thereto. By pressing the pressing portion  310 , the first holding portion  321  is spaced apart from the second holding portion  511  and the opening lever  300  moves to the second position. By opening the door  3  and sliding the waste toner container  30  in the pulling direction A 1  as shown in  FIG. 8 , the waste toner container  30  may be removed from the main body  1 , a new waste toner container  30  may be mounted in the main body  1 , and the door  3  may be closed. 
     When the second print medium cassette  90 - 2  slides in the pulling direction A 1 , the locking member  600  slides in the pulling direction A 1  by the elastic force of the elastic member  700 , thereby moving to the locking position. As shown in  FIG. 5 , when the locking member  600  arrives at the locking position, the locking portion  610  is located at a position adjacent to the second position of the first holding portion  321 , thereby locking the opening lever  300  in the first position. Thus, the door  3  cannot be opened. 
     By sliding the second print medium cassette  90 - 2  in the mounting direction A 2  to the mounted position, the interfering portion  99  of the second print medium cassette  90 - 2  is brought into contact with the releasing portion  620  of the locking member  600 . In this state, when the second print medium cassette  90 - 2  keeps sliding in the mounting direction A 2 , the locking member  600  is pushed by the second print medium cassette  90 - 2 , thereby sliding in a direction opposite to the elastic force of the elastic member  700 , i.e., in the mounting direction A 2 . When the second print medium cassette  90 - 2  arrives at the mounted position as shown in  FIG. 6 , the locking member  600  arrives at the releasing position. The opening lever  300  is in a state capable of moving from the first position to the second position, and the waste toner container  30  may be replaced. 
     It should be understood that examples described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each example should typically be considered as available for other similar features or aspects in other examples. While one or more examples have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.