Patent Publication Number: US-2023159290-A1

Title: Accommodating device and image forming apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2021-188952 filed Nov. 19, 2021. 
     BACKGROUND 
     (i) Technical Field 
     The present invention relates to an accommodating device and an image forming apparatus. 
     (ii) Related Art 
     JP2003-312870A describes a configuration where a cassette portion of a paper feeding device is diagonally disposed, a cassette (for example, A3) in a maximum size is diagonally placed, and smaller cassettes are placed above and below the cassette. 
     SUMMARY 
     Aspects of non-limiting embodiments of the present disclosure relate to an accommodating device and an image forming apparatus that a user can supply a medium to an accommodating unit and a degree of freedom in providing the accommodating unit is increased compared to a case where expanding and contracting members are attached to the same height on both sides of the accommodating unit. 
     Aspects of certain non-limiting embodiments of the present disclosure address the above advantages and/or other advantages not described above. However, aspects of the non-limiting embodiments are not required to address the advantages described above, and aspects of the non-limiting embodiments of the present disclosure may not address advantages described above. 
     According to an aspect of the present invention, there is provided an accommodating device including a device body, an accommodating unit that is movable to a supply position where a user is able to supply a medium by being pulled out from the device body in a pulling direction and of which a centroid position is located on one side surface side with respect to a center in an intersecting direction with the pulling direction, a first expanding and contracting member that expands and contracts to connect the accommodating unit to the device body so as to be able to be pulled out and is fixed to one side surface of the accommodating unit in the intersecting direction, and a second expanding and contracting member that expands and contracts to connect the accommodating unit to the device body so as to be able to be pulled out and is fixed at a position higher than the first expanding and contracting member on the other side surface of the accommodating unit in the intersecting direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiment(s) of the present invention will be described in detail based on the following figures, wherein: 
         FIG.  1    is a perspective view showing an image forming apparatus according to an exemplary embodiment of the present invention; 
         FIG.  2    is a schematic configuration view showing the image forming apparatus according to the exemplary embodiment of the present invention; 
         FIG.  3    is a configuration view showing an image forming unit of the image forming apparatus according to the exemplary embodiment of the present invention; 
         FIG.  4    is a configuration view showing an accommodating device according to the exemplary embodiment of the present invention; 
         FIG.  5    is a schematic configuration view of an accommodating unit of the accommodating device according to the exemplary embodiment of the present invention and is a view showing a state where the accommodating unit is mounted on the accommodating device; 
         FIG.  6    is a schematic configuration view of the accommodating unit of the accommodating device according to the exemplary embodiment of the present invention and is a view showing a state where the accommodating unit is pulled out from the accommodating device; 
         FIG.  7    is a cross-sectional view of the accommodating unit of the accommodating device according to the exemplary embodiment of the present invention and is a cross-sectional view taken along line A-A in  FIG.  5   ; 
         FIG.  8    is a schematic configuration view of a first expanding and contracting member of the accommodating unit of the accommodating device according to the exemplary embodiment of the present invention; 
         FIG.  9    is a schematic configuration view of a second expanding and contracting member of the accommodating unit of the accommodating device according to the exemplary embodiment of the present invention; and 
         FIG.  10    is a side view showing a state where all of the accommodating units of the accommodating device are pulled out according to the exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Examples of an accommodating device and an image forming apparatus according to an exemplary embodiment of the present invention will be described with reference to  FIGS.  1  to  10   . An arrow H shown in each drawing indicates an apparatus up-down direction, which is a vertical direction, an arrow D indicates an apparatus depth direction, which is a horizontal direction, and an arrow W indicates an apparatus width direction, which is a horizontal direction. 
     Overall Configuration of Image Forming Apparatus  10   
     As shown in  FIGS.  1  and  2   , the image forming apparatus  10  includes an image forming unit  12  that forms a toner image through an electrophotographic method, an accommodating device  110  that has accommodating units  60 ,  70 , and  80 , which accommodate a transporting unit  14  transporting the medium P along a transport path  16  and a medium P. Further, the image forming apparatus  10  includes a control unit  28  that controls each unit and a main power supply  36  that supplies electric power of a commercial power supply to each unit. 
     In the image forming apparatus  10  having the configuration, the medium P is accommodated by the accommodating units  60 ,  70 , and  80 , and the medium P accommodated in any one of the accommodating units  60 ,  70 , and  80  is transported along the transport path  16  by the transporting unit  14 . Further, a toner image formed by the image forming unit  12  is formed on the transported medium P, and the medium P on which the toner image is formed is discharged to the outside of an apparatus body  10   a.    
     Image Forming Unit  12   
     As shown in  FIG.  2   , the image forming unit  12  includes a plurality of toner image forming units  30  that form respective colors of toner images and a transfer unit  32  that transfers the toner images formed by the toner image forming units  30  to the medium P. Further, the image forming unit  12  includes a fixing device  34  that fixes the toner images, which are transferred to the medium P by the transfer unit  32 , to the medium P. 
     Toner Image Forming Unit  30   
     The plurality of toner image forming units  30  are included to form a toner image for each color. In the present exemplary embodiment, in total, four colors of yellow (Y), magenta (M), cyan (C), and black (K) toner image forming units  30  are provided. In the following description, in a case where it is not necessary to distinguish between yellow (Y), magenta (M), cyan (C), and black (K), Y, M, C, and K attached to the reference numerals are omitted. 
     As shown in  FIG.  3   , the toner image forming unit  30  having each color is basically configured the same except for a toner to be used and includes a rotating cylindrical image holding body  40  and a charger  42  that charges the image holding body  40 . Further, the toner image forming unit  30  includes an exposure device  44  that irradiates the charged image holding body  40  with exposure light and forms an electrostatic latent image and a developing device  46  that develops the electrostatic latent image with a developer G including a toner as a toner image. Accordingly, the toner image forming unit  30  having each color forms an image having each color using each color of toner. 
     In addition, as shown in  FIG.  2   , the image holding body  40  having each color is in contact with a transfer belt  50  (details to be described later) that moves around. In a circumferential direction (see an arrow in  FIG.  2   ) of the transfer belt  50 , the yellow (Y), magenta (M), cyan (C), and black (K) toner image forming units  30  are arranged side by side in turn from an upstream side. 
     Transfer Unit  32   
     As shown in  FIG.  2   , the transfer unit  32  includes the transfer belt  50  and primary transfer rollers  52  each of which is arranged on an opposite side of the image holding body  40  having each color with the transfer belt  50  sandwiched therebetween and transfers a toner image formed on the image holding body  40  having each color to the transfer belt  50 . 
     In addition, the transfer unit  32  includes a winding roller  56  around which the transfer belt  50  is wound and a drive roller  58  around which the transfer belt  50  is wound and which transmits a rotational force to the transfer belt  50 . Accordingly, the transfer belt  50  moves around in an arrow direction in  FIG.  2   . 
     Further, the transfer unit  32  includes a secondary transfer roller  54  that is arranged on the opposite side of the winding roller  56  with the transfer belt  50  sandwiched therebetween and transfers a toner image transferred to the transfer belt  50  to the medium P. A transfer nip NT where the toner image is transferred to the medium P is formed between the secondary transfer roller  54  and the transfer belt  50 . 
     In the configuration, in order of yellow (Y), magenta (M), cyan (C), and black (K), the toner image is primarily transferred to the transfer belt  50  by the primary transfer roller  52 . On the other hand, the toner image is transferred by the secondary transfer roller  54  from the transfer belt  50  to the medium P transported while being sandwiched between the transfer belt  50  and the secondary transfer roller  54 . Further, the medium P on which the toner image is transferred is transported toward the fixing device  34 . 
     Fixing Device  34   
     As shown in  FIG.  2   , the fixing device  34  is arranged on a downstream side of the transfer nip NT in a transport direction of the medium P. The fixing device  34  heats and pressurizes the toner image transferred to the medium P and fixes the toner image to the medium P. 
     Accommodating Device  110   
     As shown in  FIG.  2   , the accommodating device  110  includes the three accommodating units  60 ,  70 , and  80  that are arranged at a lower portion of the image forming apparatus  10  and accommodate the medium P and the transporting unit  14  which transports the medium P. The accommodating unit  60  arranged at the uppermost is inclined with respect to the horizontal direction. Details of the accommodating device  110  will be described later. 
     Control Unit  28  and Main Power Supply  36   
     The control unit  28  and the main power supply  36  are arranged in a triangular region formed between the inclined accommodating unit  60  and the image forming unit  12 . 
     Major Portion Configuration 
     Next, the accommodating device  110  will be described. As shown in  FIGS.  1  and  2   , the accommodating device  110  is arranged at the lower portion of the image forming apparatus  10 . A device body  110   a  of the accommodating device  110  is formed integrally with the apparatus body  10   a  of the image forming apparatus  10 . 
     As shown in  FIG.  4   , the accommodating device  110  includes the device body  110   a,  the accommodating unit  60  that accommodates the medium P, the accommodating unit  70  that accommodates the medium P, and the accommodating unit  80  that accommodates the medium P. In addition, the accommodating device  110  includes a slide rail  68  that makes the accommodating unit  60  capable of moving in the apparatus depth direction D, a slide rail  78  that makes the accommodating unit  70  capable of moving in the apparatus depth direction D, and a slide rail  88  that makes the accommodating unit  80  capable of moving in the apparatus depth direction D. The accommodating unit  60 , the accommodating unit  70 , and the accommodating unit  80  are arranged from an upper side to a lower side in this order. 
     In the present exemplary embodiment, for example, the accommodating unit  60  generally accommodates the A3 medium P, and the A3 medium P is the medium P in the maximum size that can be accommodated in the accommodating unit  60 . In addition, the accommodating unit  70  generally accommodates the postcard-sized medium P, and the postcard-sized medium P is the medium P in the maximum size that can be accommodated in the accommodating unit  70 . The accommodating unit  80  generally accommodates the A4 medium P, and the A4 medium P is the medium P in the maximum size that can be accommodated in the accommodating unit  80 . 
     In addition, in the present exemplary embodiment, for example, the accommodating unit  60  can accommodate 200 media P, the accommodating unit  70  can accommodate 100 media P, and the accommodating unit  80  can accommodate 1,000 media P. In the image forming apparatus  10 , it is assumed that the consumption of the A4 medium P is the largest. That is, the number of sheets that can be accommodated in the accommodating unit  80  accommodating the media P of which the consumption is the largest is larger than the number of sheets that can be accommodated in the accommodating unit  60  and the number of sheets that can be accommodated in the accommodating unit  70 . 
     Castors  120  are attached to four corners of a lower surface  111  of the accommodating device  110 . Attachment surfaces  111   b  for the castors  120  of the lower surface  111  of the accommodating device  110  are configured at positions higher than a center portion  111   a  of the lower surface  111  in the apparatus up-down direction H. 
     Transporting Unit  14   
     As shown in  FIG.  2   , the transporting unit  14  includes a feeding roller  20   a  that feeds the medium P accommodated in the accommodating unit  60  to the transport path  16  and a prevention roller  22   a  that prevents double-feeding of the media P fed by the feeding roller  20   a.    
     In addition, the transporting unit  14  includes a feeding roller  20   b  that feeds the medium P accommodated in the accommodating unit  70  to the transport path  16  and a prevention roller  22   b  that prevents double-feeding of the media P fed by the feeding roller  20   b.    
     Further, the transporting unit  14  includes a feeding roller  20   c  that feeds the medium P accommodated in the accommodating unit  80  to the transport path  16  and a prevention roller  22   c  that prevents double-feeding of the media P fed by the feeding roller  20   c.    
     In addition, the transporting unit  14  includes an adjusting roller  24  that is arranged on the downstream side of the prevention rollers  22   a,    22   b,  and  22   c  in the transport direction of the medium P and adjusts a timing when the medium P is fed to the transfer nip NT. Further, the transporting unit  14  includes a discharge roller  26  that discharges the medium P to which a toner image is fixed by the fixing device  34  to the outside of the apparatus body  10   a.    
     Accommodating Unit  60  and Slide Rail  68   
     As shown in  FIG.  4   , the accommodating unit  60  has a box shape of which an upper side is open and accommodates a medium in the device body  110   a.  The accommodating unit  60  is another accommodating unit in the technique of the present invention. A pair of slide rails  68  are attached to both ends of the accommodating unit  60  in the apparatus width direction W respectively. The slide rail  68  includes an outer member, an intermediate member, and an inner member, the outer member is attached to the device body  110   a,  and the inner member is attached to the accommodating unit  60 . 
     Accordingly, in a case where a user pulls out the accommodating unit  60  mounted on the device body  110   a  to a front side in the apparatus depth direction D, the accommodating unit  60  is guided by the slide rail  68  and is detached from the device body  110   a.  In addition, in a case where the user pushes in the accommodating unit  60  detached from the device body  110   a  to a back side in the apparatus depth direction D, the accommodating unit  60  is guided by the slide rail  68  and is mounted on the device body  110   a.    
     In addition, as shown in  FIG.  4   , the accommodating unit  60  is inclined with respect to the horizontal direction such that vertical positions of one end (end portion on the left in  FIG.  4   ) and the other end in the apparatus width direction are different from each other in a case of being viewed from the apparatus depth direction D in a state of being mounted on the device body  110   a  and a state of being detached from the device body  110   a.  Specifically, the accommodating unit  60  is inclined with respect to the horizontal direction such that the one end in the apparatus width direction is above the other end in a case of being viewed from the apparatus depth direction D. Herein, the one end and the other end are parts of the accommodating unit  60  and are one and the other of two points separated the most in the apparatus width direction. 
     In a state where the accommodating unit  60  is mounted on the device body  110   a,  the medium P accommodated in the accommodating unit  60  can be transported by the transporting unit  14 . In other words, the accommodating unit  60  mounted on the device body  110   a  is located at a transport position where the accommodated medium P can be transported. 
     On the other hand, in a case where the user pulls out the accommodating unit  60  mounted on the device body  110   a  to the front side in the apparatus depth direction D, the accommodating unit  60  is guided by the slide rail  68 , is abutted against a stopper (not shown) so as to be stopped, and is detached from the device body  110   a.  In addition, in a case where the user pushes in the accommodating unit  60  detached from the device body  110   a  to the back side in the apparatus depth direction D, the accommodating unit  60  is guided by the slide rail  68  and is mounted on the device body  110   a.  The detachment is a state where the medium P can be accommodated in the accommodating unit  60 . In the present exemplary embodiment, a state where the accommodating unit  60  is detached from the device body  110   a  is a state where the accommodating unit  60  is not removed from the device body  110   a  and is supported by the device body  110   a  and is a state where the medium P can be accommodated in the accommodating unit  60 . 
     Then, in a state where the accommodating unit  60  is detached from the device body  110   a,  an upper side of the accommodating unit  60  is opened, and the medium P can be supplied to the accommodating unit  60 . In other words, the accommodating unit  60  detached from the device body  110   a  is located at a supply position where the medium P can be supplied to the accommodating unit  60 . 
     Accommodating Unit  70  and Slide Rail  78   
     As shown in  FIG.  4   , the accommodating unit  70  has a box shape of which an upper side is open and accommodates a medium in the device body  110   a.  The accommodating unit  70  is another accommodating unit in the technique of the present invention. A pair of slide rails  78  are attached to both ends of the accommodating unit  70  in the apparatus width direction W respectively. 
     The slide rail  78  includes an outer member, an intermediate member, and an inner member, the outer member is attached to the device body  110   a,  and the inner member is attached to the accommodating unit  70 . 
     Accordingly, in a case where the user pulls out the accommodating unit  70  mounted on the device body  110   a  to the front side in the apparatus depth direction D, the accommodating unit  70  is guided by the slide rail  78  and is detached from the device body  110   a.  In addition, in a case where the user pushes in the accommodating unit  70  detached from the device body  110   a  to the back side in the apparatus depth direction D, the accommodating unit  70  is guided by the slide rail  78  and is mounted on the device body  110   a.    
     In addition, in a state of being mounted on the device body  110   a  and a state of being detached from the device body  110   a,  the accommodating unit  70  is horizontally arranged in a case of being viewed from the apparatus depth direction D. The fact that the accommodating unit  70  is horizontally arranged in the present exemplary embodiment may mean being arranged along the horizontal direction, and that is, for example, a state where the medium P accommodated in the accommodating unit  70  is allowed to be slightly inclined so as not to move due to the inclination. 
     Then, the accommodating unit  70  mounted on the device body  110   a  is located at the transport position where the accommodated medium P can be transported, and the accommodating unit  70  detached from the device body  110   a  is located at the supply position where the medium P can be supplied to the accommodating unit  70 . 
     Accommodating Unit  80  and Slide Rails  88  and  89   
     As shown in  FIGS.  4  to  7   , the accommodating unit  80  has a box shape of which an upper side is open and accommodates the medium P in the device body  110   a.  The accommodating unit  80  is an accommodating unit in the technique of the present invention. A pair of slide rails  88  and  89  are attached to both ends of the accommodating unit  80  in the apparatus width direction W respectively. The slide rail  88  is fixed to one side surface  80   c  of the accommodating unit  80  in the apparatus width direction W. The slide rail  88  is a first expanding and contracting member in the technique of the present invention. The slide rail  89  is fixed to a position higher than the slide rail  88  on the other side surface  80   d  of the accommodating unit  80  in the apparatus width direction W. The slide rail  89  is a second expanding and contracting member in the technique of the present invention. 
     In the present exemplary embodiment, the apparatus depth direction D and a pulling direction B of the accommodating unit  80  are parallel to each other, a pulling direction B side in the apparatus depth direction D will be defined as an apparatus front side, and an opposite side to the pulling direction B in the apparatus depth direction D will be defined as an apparatus back side. In addition, the apparatus width direction W corresponds to an intersecting direction in the technique of the present invention. In the present exemplary embodiment, the fact that the apparatus depth direction D and the pulling direction B of the accommodating unit  80  are parallel to each other may mean that both are practically parallel to each other, and an angle difference between both directions is in a state of allowing an error of approximately ±5°. 
     By being pulled in the pulling direction B in a state of being mounted on the accommodating device  110  as shown in  FIG.  5   , the accommodating unit  80  comes into a state of being pulled out from the accommodating device  110  as shown in  FIG.  6   . 
     As shown in  FIGS.  5  to  7   , the accommodating unit  80  includes a front panel  81 , a medium holding unit  82 , a medium holding plate  83  that is attached to the medium holding unit  82 , an adjusting member  84  for adjusting an accommodated size of the medium P in the apparatus width direction W, two adjusting members  85  for adjusting the accommodated size of the medium P in the apparatus depth direction D, and a moving mechanism  86  for moving the medium P accommodated in the accommodating unit  80  upward in the vertical direction. 
     The front panel  81  is a panel exposed to a front surface of the accommodating device  110  in a state where the accommodating unit  80  is mounted on the accommodating device  110  and is configured of, for example, a resin. 
     The medium holding unit  82  is a box-shaped member of which an upper side where the medium P is provided is open and is configured such that a provision surface for the medium P is an upper surface  80   e  of the box-shaped accommodating unit  80 . A panel of a side surface  82   a  of the medium holding unit  82  is formed of a metal, and the other portion  82   b  is formed of a resin. The side surface  82   a  of the medium holding unit  82  is a surface that is the one side surface  80   c  of the accommodating unit  80 . That is, in the apparatus width direction W, a side wall of the one side surface  80   c  of the accommodating unit  80  is formed of a metal, and a side wall of the other side surface  80   d  is formed of a resin. Herein, examples of the metal forming the side wall of the side surface  80   c  include iron, stainless steel, aluminum, nickel, magnesium, titanium, copper, and alloys containing these metals. In addition, examples of the resin forming the side wall of the side surface  80   d  include polyethylene, polypropylene, vinyl chloride resin, an acrylonitrile butadiene style (ABS) resin, polycarbonate, and epoxy. 
     The medium holding plate  83  is a plate-shaped member that holds the medium P in the medium holding unit  82  and is attached to the medium holding unit  82  so as to be movable in the apparatus up-down direction H. 
     The adjusting member  84  is attached to the medium holding unit  82  so as to be movable in the apparatus width direction W. The two adjusting members  85  is attached to the medium holding unit  82  so as to be movable symmetrically in synchronization with a center position of an accommodation region of the medium P as reference in the apparatus depth direction D. The adjusting member  84  and the two adjusting members  85  are moved manually by the user. 
     The moving mechanism  86  is a mechanism for moving the medium P accommodated in the accommodating unit  80  upward in the vertical direction and bringing the medium P into contact with the feeding roller  20   c  and is attached to a position closer to the slide rail  88  than the slide rail  89  in the apparatus width direction W. 
     The moving mechanism  86  is realized by, for example, a gear mechanism including a plurality of gears. The gear mechanism, which is the moving mechanism  86 , is connected to a drive unit  130  in the device body  110   a  in a state where the accommodating unit  80  is mounted on the accommodating device  110 . The drive unit  130  is realized by, for example, a motor. 
     A rotation shaft of the motor and rotation shafts of the plurality of gears configuring the gear mechanism are both configured to be shafts parallel to the apparatus depth direction D. In addition, the medium holding plate  83  is connected to one of the rotation shafts of the gear mechanism by a wire. By rotating the gear mechanism with the motor and winding the wire attached to the one of the rotation shafts of the gear mechanism in a state where the accommodating unit  80  is mounted on the accommodating device  110 , the medium holding plate  83  connected to the wire can be moved upward together with the medium P. 
     The accommodating unit  80  configured as described above is configured such that a centroid position is located on one side surface  80   c  side with respect to a center CW in the apparatus width direction W. The relationship is maintained even in a case where a maximum number of sheets of the media P having the maximum size, which can be accommodated, are accommodated in the accommodating unit  80 . 
     In the present exemplary embodiment, the center CW of the accommodating unit  80  in the apparatus width direction W means a center of a body portion accommodating the medium P in the apparatus width direction W, excluding a panel of a front surface  80   a  and a panel of a back surface  80   b  in the accommodating unit  80 . Specifically, as shown in  FIG.  7   , the center CW is a center position of a region R 1  between the side surfaces  80   c  and  80   d,  which is the width of the body portion of the accommodating unit  80 , which accommodates the medium P. In the present exemplary embodiment, the body portion of the accommodating unit  80  is configured by the medium holding unit  82 . For this reason, the side surfaces  80   c  and  80   d  of the accommodating unit  80  in the apparatus width direction W are the same as both side surfaces of the medium holding unit  82  in the apparatus width direction W. However, in a case where another member is attached to the medium holding unit  82 , an outermost position in the apparatus width direction W is a side surface, including the other member. Therefore, the position of “the center CW of the accommodating unit  80  in the apparatus width direction W” does not change depending on the shapes and sizes of the panel of the front surface  80   a  and the panel of the back surface  80   b  of the accommodating unit  80 . 
     As shown in  FIG.  7   , the accommodating unit  80  is configured to accommodate the medium P by bringing the medium P into contact with an inner wall surface  80   g  on a slide rail  88  side with respect to the center CW of the accommodating unit  80  in the apparatus width direction W. The medium P is brought into contact with the feeding roller  20   c  by the moving mechanism  86  in a state where the accommodating unit  80  is mounted on the accommodating device  110 , and is transported from the one side surface  80   c  side of the accommodating unit  80  along a transport direction T parallel to the apparatus width direction W. 
     In the present exemplary embodiment, the pulling direction B of the accommodating unit  80  and a side Pa of the medium P on a leading end side in the transport direction T are substantially parallel to each other. The side surface  80   c  of the accommodating unit  80  is a surface arranged along the side Pa of the medium P on the leading end side. The side surface  80   d  is a surface on an opposite side to the side surface  80   c  of the accommodating unit  80 . In the present exemplary embodiment, the fact that the pulling direction B of the accommodating unit  80  and the side Pa of the medium P on the leading end side in the transport direction T are parallel to each other may mean that both are practically parallel to each other, and an angle difference between both directions is in a state of allowing an error of approximately ±5°. 
     The slide rail  88  is an example of the first expanding and contracting member that expands and contracts to connect the accommodating unit  80  to the device body  110   a  so as to be able to be pulled out. As shown in  FIG.  8   , the slide rail  88  includes an outer member  88   a,  an intermediate member  88   b,  and an inner member  88   c,  the outer member  88   a  is fixed to an inner side surface  112  of a castor mounting portion in the device body  110   a  and a slide rail fixing portion  113 , and the inner member  88   c  is attached to the one side surface  80   c  of the accommodating unit  80 . 
     The outer member  88   a,  the intermediate member  88   b,  and the inner member  88   c  are each configured of one metal sheet. That is, the slide rail  88  includes three metal sheets as a whole. The slide rail  88  is configured to accommodate the intermediate member  88   b  and the inner member  88   c  in the outer member  88   a  in a state where the slide rail  88  is contracted. 
     The slide rail  89  is an example of the second expanding and contracting member that expands and contracts to connect the accommodating unit  80  to the device body  110   a  so as to be able to be pulled out. As shown in  FIG.  9   , the slide rail  89  includes an outer member  89   a,  an intermediate member  89   b,  and an inner member  89   c,  the outer member  89   a  is fixed to a slide rail fixing portion  114  in the device body  110   a,  and the inner member  89   c  is attached to the other side surface  80   d  of the accommodating unit  80 . 
     The outer member  89   a  and the inner member  89   c  are each configured of one metal sheet. The intermediate member  89   b  is configured in a form in which an inner member portion  89   b   1  formed of one metal sheet, an outer member portion  89   b   2  formed of one metal sheet, and a reinforcing member portion  89   b   3  formed of one metal sheet are integrated with each other. The reinforcing member portion  89   b   3  is a reinforcing member that extends parallel to the inner member portion  89   b   1  and the outer member portion  89   b   2  and is used for improving the rigidity of the entire intermediate member  89   b.  That is, the slide rail  89  includes five metal sheets as a whole. 
     In a state where the slide rail  89  is contracted, the slide rail  89  is configured such that the inner member portion  89   b   1  of the intermediate member  89   b  is accommodated in the outer member  89   a  and the inner member  89   c  is accommodated in the outer member portion  89   b   2  of the intermediate member  89   b.    
     A withstanding load of the slide rail  89  is configured to be higher than a withstanding load of the slide rail  88 . The number of metal sheets of the slide rail  89  is larger than the number of metal sheets of the slide rail  88 . In addition, in the apparatus width direction W, a width W 2  of the slide rail  89  is larger than a width W 1  of the slide rail  88 . All of these are beneficial configurations for making the withstanding load of the slide rail  89  higher than the withstanding load of the slide rail  88 . 
     A lower surface  80   f  of the accommodating unit  80  is located below the attachment surfaces  111   b  for the castors  120  in the apparatus up-down direction H. In addition, the accommodating unit  80 , the slide rail  88 , and the castors  120  are arranged at positions overlapping each other in the apparatus up-down direction H. In addition, in a state where the medium P is accommodated in the accommodating unit  80 , the accommodating unit  80 , the medium P, the slide rail  88 , and the castors  120  are arranged at positions overlapping each other in the apparatus up-down direction H. 
     With the configuration, in a case where the user pulls out the accommodating unit  80  mounted on the device body  110   a  in the pulling direction B, that is, to the front side in the apparatus depth direction D, the accommodating unit  80  is guided by the slide rails  88  and  89  and is detached from the device body  110   a.  In addition, in a case where the user pushes in the accommodating unit  80  detached from the device body  110   a  to the back side in the apparatus depth direction D, the accommodating unit  80  is guided by the slide rails  88  and  89  and is mounted on the device body  110   a.    
     In addition, as shown in  FIG.  4   , in a state of being mounted on the device body  110   a  and a state of being detached from the device body  110   a,  the accommodating unit  80  is horizontally arranged in a case of being viewed from the apparatus depth direction D. The fact that the accommodating unit  80  is horizontally arranged in the present exemplary embodiment may mean being arranged along the horizontal direction, and that is, for example, a state where the medium P accommodated in the accommodating unit  80  is allowed to be slightly inclined so as not to move due to the inclination. 
     Then, the accommodating unit  80  mounted on the device body  110   a  is located at the transport position where the accommodated medium P can be transported, and the accommodating unit  80  detached from the device body  110   a  is located at the supply position where the medium P can be supplied to the accommodating unit  80 . 
     Overall Configuration of Accommodating Device  110   
     As described above, the accommodating device  110  includes, in addition to the accommodating unit  80  in the technique of the present invention, the other accommodating units  60  and  70  that can be pulled out in the same pulling direction B as in the accommodating unit  80 . As shown in  FIG.  10   , all of the front surfaces  60   a,    70   a,  and  80   a  of the accommodating unit  60 ,  70 , and  80  are configured to be able to be pulled out to substantially the same position in the pulling direction B. The front surface of each accommodating unit is a front side surface of the accommodating unit, which faces the pulling direction B. In the present exemplary embodiment, the fact that all of the front surfaces  60   a,    70   a,  and  80   a  of the accommodating units  60 ,  70 , and  80  can be pulled out to substantially the same position in the pulling direction B may mean that the front surfaces  60   a,    70   a,  and  80   a  can be practically pulled out to the same position, and that is, a state where a maximum error between the respective surfaces is allowed to be an error of approximately 1 cm, which is approximately the thickness of the front panel. 
     Operations of Accommodating Device  110  and Image Forming Apparatus  10   
     As described above, in the accommodating device  110 , as for the two slide rails  88  and  89  fixed to both ends of the accommodating unit  80  in the apparatus width direction W respectively, the slide rail  89  fixed to the other side surface  80   d  of the accommodating unit  80  is fixed to a position higher than the slide rail  88  fixed to the one side surface  80   c  of the accommodating unit  80 . Accordingly, compared to a case where slide rails are provided at the same height on both sides of the accommodating unit  80 , a degree of freedom in providing the accommodating unit  80  including the slide rails  88  and  89  is increased after ensuring necessary attachment strength by identifying a centroid position or identifying a withstanding load difference. In addition, since the degree of freedom in providing the accommodating unit  80  is high, the accommodating device  110  is easily miniaturized. 
     In a case where the slide rails  88  and  89  are fixed at heights different from each other at both ends of the accommodating unit  80  in the apparatus width direction W, a load is more likely to be applied to the slide rail  89  fixed to a higher position than the slide rail  88  fixed to a lower position. As described above, in a case where a load is not uniformly applied to the two slide rails  88  and  89  fixed to both ends of the accommodating unit  80  in the apparatus width direction W respectively and a load applied to the slide rail  89  on one side is larger, durability of an attachment portion of the accommodating unit  80  with respect to the accommodating device  110  may decrease. 
     For this reason, the accommodating unit  80  configured as described above is configured such that the centroid position is located on the one side surface  80   c  side with respect to the center CW in the apparatus width direction W. Accordingly, an increase in a load applied to the slide rail  89  is suppressed. 
     In addition, in the apparatus width direction W, the side wall of the one side surface  80   c  of the accommodating unit  80  is formed of a metal, and the side wall of the other side surface  80   d  is formed of a resin. Accordingly, an increase in a load applied to the slide rail  89  is suppressed. 
     In addition, the moving mechanism  86  is attached to a position closer to the slide rail  88  than the slide rail  89  in the apparatus width direction W. As described above, by arranging functional components of the accommodating unit  80 , the centroid is brought closer to the slide rail  88  side. 
     In addition, the withstanding load of the slide rail  89  is configured to be higher than the withstanding load of the slide rail  88 . Accordingly, compared to a case where the withstanding loads of the slide rails  88  and  89  are the same or the withstanding load of the slide rail  88  is higher than the withstanding load of the slide rail  89 , the slide rail  88  is easily miniaturized and decreased in weight. 
     In addition, the number of metal sheets of the slide rail  89  is configured to be larger than the number of metal sheets of the slide rail  88 . Accordingly, compared to a case where the number of metal sheets of the slide rail  89  is the same as the number of metal sheets of the slide rail  88  or is smaller than the number of metal sheets of the slide rail  88 , it is easy to make the withstanding load of the slide rail  89  higher than the withstanding load of the slide rail  88 . 
     In addition, in the apparatus width direction W, the width W 2  of the slide rail  89  is configured to be larger than the width W 1  of the slide rail  88 . Accordingly, compared to a case where the width of the slide rail  89  is the same as the width of the slide rail  88  or is smaller than the width of the slide rail  88 , it is easy to make the withstanding load of the slide rail  89  higher than the withstanding load of the slide rail  88 . 
     In addition, the medium P accommodated in the accommodating unit  80  is transported from the one side surface  80   c  side of the accommodating unit  80  to the outside along the transport direction T parallel to the apparatus width direction W. Accordingly, compared to a case where the medium P is transported from the other side surface  80   d  side of the accommodating unit  80  to the outside, an increase in a load applied to the slide rail  89  in a case of transporting the medium P is suppressed. 
     In addition, it is assumed that the A4 medium P is used the most in the image forming apparatus  10 . For this reason, in a case where the accommodating unit  80  of the present exemplary embodiment is configured to be capable of accommodating 1,000 sheets of the A4 media P, the weight of the accommodating unit  80  including the media P is extremely great in a state where the maximum number of sheets of the media P are accommodated in the accommodating unit  80 . For this reason, in the present exemplary embodiment, the lower surface  80   f  of the accommodating unit  80  is configured to be located below the attachment surfaces  111   b  for the castors  120  in the apparatus up-down direction H. Accordingly, compared to a case where the lower surface  80   f  of the accommodating unit  80  is located above the attachment surfaces  111   b  for the castors  120 , the centroid of the entire accommodating device  110  is lowered in a state where the medium P is accommodated in the accommodating unit  80 . 
     In addition, the accommodating unit  80 , the slide rail  88 , and the castors  120  are arranged at positions overlapping each other in the apparatus up-down direction H. That is, the accommodating unit  80  is arranged in a form of being interposed between the castors  120  on both sides in the apparatus width direction W. Accordingly, compared to a case where the accommodating unit  80 , the slide rail  88 , and the castors  120  are arranged at positions different from each other in the apparatus up-down direction H, the centroid of the entire accommodating device  110  is lowered in a state where the medium P is accommodated in the accommodating unit  80 . In addition, in such a case, by fixing the slide rail  89  at a position not interposed between the castors  120 , an increase in the length of the apparatus width direction W can be suppressed compared to a case where the slide rails  88  and  89  on both sides of the accommodating unit  80  are fixed at positions interposed between the castors  120 . 
     In addition, the accommodating device  110  includes, in addition to the accommodating unit  80  in the technique of the present invention, the other accommodating units  60  and  70  that can be pulled out in the same pulling direction B as in the accommodating unit  80 . All of the front surfaces  60   a,    70   a,  and  80   a  of the accommodating unit  60 ,  70 , and  80  are configured to be able to be pulled out to substantially the same position in the pulling direction B. Accordingly, in a case of including a plurality of accommodating units, beauty of the apparatus appearance and safety in a state where all of the accommodating units are pulled out are improved compared to a case where the front surfaces of the accommodating units are at positions different from each other in a state where all of the accommodating units are pulled out. 
     In addition, compared to a case where the accommodating device  110  is not included in the image forming apparatus  10 , a range necessary in a case of supplying the medium P to the image forming apparatus  10  is decreased. 
     Although details of a certain exemplary embodiment of the present invention have been described, the present invention is not limited to such an exemplary embodiment, and it is clear for those skilled in the art that the present invention can take other various exemplary embodiments within the scope of the present invention. 
     For example, although the accommodating device  110  is used in the image forming apparatus  10  adopting the electrophotographic method in the exemplary embodiment, for example, the accommodating device  110  may be used in an image forming apparatus adopting an inkjet method. In addition, the accommodating device is not limited to being applied to the image forming apparatus and may be applied to an optional device such as a paper feeding device. 
     In addition, an arrangement position, an arrangement inclination state, a shape, a size, and a maximum pulling amount with respect to the device body  110   a  of the accommodating device  110  of each of the accommodating unit  60 , the accommodating unit  70 , and the accommodating unit  80  are not limited to the exemplary embodiment. In addition, although the accommodating device  110  includes the accommodating unit  60 , the accommodating unit  70 , and the accommodating unit  80  in the exemplary embodiment, the accommodating unit  60  and the accommodating unit  80  may not be included. In this case, operations achieved by including the accommodating unit  60  and the accommodating unit  80  cannot be achieved. 
     In addition, the accommodating device  110  may be provided with an openable and closable cover covering the accommodating unit  60 , the accommodating unit  70 , and the accommodating unit  80 . 
     In addition, the slide rail  88  is not limited to being configured by three members including the outer member  88   a  attached to the device body  110   a  of the accommodating device  110 , the intermediate member  88   b,  and the inner member  88   c  attached to the accommodating unit  80 , and other forms may be adopted. For example, the slide rail  88  may be configured by two members including a guide member attached to the device body  110   a  of the accommodating device  110  and a guided member attached to the accommodating unit  80 . In addition, a member of the slide rail  88 , which is attached to the device body  110   a  of the accommodating device  110 , may be configured to be integrated with the device body  110   a.  Similarly, a member of the slide rail  88 , which is attached to the accommodating unit  80 , may be configured to be integrated with the accommodating unit  80 . 
     In addition, also the slide rail  89  may be in another form, similar to the slide rail  88 . In addition, the slide rail  88  and the slide rail  89  are not limited to having structures different from each other as in the exemplary embodiment and may have the same structure. In addition, the expanding and contracting member is not limited to the slide rail and may be another mechanism such as an air cylinder. 
     The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.