Patent Publication Number: US-8985574-B2

Title: Image forming apparatus

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. application Ser. No. 13/425,291, filed on Mar. 20, 2012, which claims priority to Japanese Patent Application No. 2011-064747, filed on Mar. 23, 2011, which are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     The present disclosure relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a multifunction peripheral combining such devices. 
     Conventionally, an image forming apparatus such as a copying machine, a printer, a facsimile or a multifunction peripheral combining such devices has been known as an apparatus for forming (printing) an image on a sheet of paper used as a sheet medium. These types of image forming apparatuses generally include a stacking unit that has a stacking surface portion. Discharged sheets of paper are stacked on the stacking surface portion. 
     The stacking surface portion must have a length that enables stacking of sheets of paper having maximum length in a direction in which the sheets of paper are discharged from a discharging portion so that these sheets can be stacked on the stacking surface portion. The above requirement is a reason causing an increase in the overall size of the image forming apparatus. 
     In this regard, a plurality of image forming apparatuses has been proposed that enables an increase in the surface area of a stacking surface portion to deal with large-size sheets of paper. One of such image forming apparatuses is configured to rotate a folded auxiliary tray. In this manner, the surface area of the stacking surface portion can be increased. Furthermore, one of such image forming apparatuses is configured so that a folded auxiliary tray is raised in operable connection with mounting of a sheet feeding cassette, when the sheet feeding cassette containing large-size sheets of paper is mounted in a main cabinet. In this manner, the surface area of a stacking surface portion can be increased. 
     SUMMARY 
     However, when large-size sheets of paper are stacked on the stacking surface portion, the image forming apparatuses described above are configured to rotate or raise the auxiliary tray. Therefore, these types of image forming apparatuses result in an increase in the required surface area (volume) outside the apparatus. 
     Consequently, there has been a demand for an image forming apparatus including a stacking unit that is configured to inhibit an increase in the apparatus size for a case where large-size sheets of paper are stacked on a stacking surface portion. 
     The present disclosure provides an image forming apparatus that includes a stacking unit that is configured to inhibit an increase in the apparatus size. 
     The present disclosure provides an image forming apparatus, which includes a housing, an image forming unit disposed inside the housing, a discharging portion, a stacking unit and a pressing member. The discharging portion is configured to discharge a sheet medium on which an image is formed by the image forming unit. The stacking unit is configured to stack the sheet medium discharged from the discharging portion. The stacking unit includes a stacking surface portion on which the sheet medium is stacked. The stacking surface portion includes a planar portion formed flat, and a protruding portion configured to protrude upwardly from the planar portion and/or a recessed portion configured to be indented downwardly at the planar portion. The pressing member is disposed in contact with an upper surface of the sheet medium stacked on the stacking surface portion. 
     The present disclosure provides the image forming apparatus that includes the stacking unit that is configured to inhibit an increase in the apparatus size. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  illustrates the disposition of each constituent element in a copying machine  1  according to a first embodiment of the present disclosure; 
         FIG. 2  is a side view illustrating the configuration of a pressing member  200  and an inner accumulating portion  510  according to the first embodiment; 
         FIG. 3  is a perspective view illustrating the configuration of the pressing member  200  and a stacking surface portion  520  according to the first embodiment; 
         FIG. 4  is a perspective view illustrating the configuration of the stacking surface portion  520  according to the first embodiment; 
         FIG. 5  is a side view illustrating an enlargement of the pressing member  200  in  FIG. 2 ; 
         FIG. 6A  illustrates an operation of simplex printing in which a sheet of paper T starts to be conveyed in a discharging direction D 1 ; 
         FIG. 6B  illustrates an operation of simplex printing in which a sheet of paper T is conveyed along a first protruding portion  523 ; 
         FIG. 6C  illustrates an operation of simplex printing in which a sheet of paper T abuts with a pressing member  200  in a stiff configuration; 
         FIG. 6D  illustrates an operation of simplex printing in which the distal end of a sheet of paper T has moved towards a distal end portion  202  of the pressing member  200 ; 
         FIG. 6E  illustrates an operation of simplex printing in which a sheet of paper T has caused the pressing member  200  to rotate; 
         FIG. 6F  illustrates an operation of simplex printing in which a sheet of paper T is being conveyed in the discharging direction D 1  in contact with the distal end portion  202  of the pressing member  200 ; 
         FIG. 6G  illustrates an operation of simplex printing in which a sheet of paper T is stacked on the stacking surface portion  520  after completion of simplex printing; 
         FIG. 7  is a perspective view illustrating the configuration of a pressing member  200 A according to a second embodiment; 
         FIG. 8  is a perspective view illustrating the configuration of a pressing member  200 B according to a third embodiment; 
         FIG. 9  is a side view illustrating the configuration of the pressing member  200 A and an inner accumulating portion  510 A according to a fourth embodiment; 
         FIG. 10  is a perspective view illustrating the configuration of a stacking surface portion  520 A with sheets of paper T stacked according to the fourth embodiment; and 
         FIG. 11  is a perspective view illustrating the configuration of the stacking surface portion  520 A without the sheets of paper T stacked according to the fourth embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     A first embodiment of a copying machine  1  will be described below as an example of an image forming apparatus according to the present disclosure making reference to the figures. 
       FIG. 1  illustrates the disposition of each constituent element in the copying machine  1  according to the first embodiment of the present disclosure. 
     As illustrated in  FIG. 1 , the copying machine  1  representing the first embodiment of the present disclosure includes a main cabinet M, an image reading device  300 , a relay unit  500 , and a post-processing device  600 . The image reading device  300  is attached to a top portion of the main cabinet M. The relay unit  500  is attached to the main cabinet M. The post-processing device  600  is attached to the main cabinet M. 
     As illustrated in  FIG. 1 , the relay unit  500  and the post-processing device  600  are optionally attached to the main cabinet M of the copying machine  1 . 
     The image reading device  300  is disposed on an upper end portion of the copying machine  1  in a vertical direction Z. The image reading device  300  reads an image of a document. The image reading device  300  outputs image information related to the read image to the main cabinet M (image forming unit). 
     The main cabinet M uses the image information sent from the image reading apparatus  300  to form a toner image on a sheet of paper T, which is an example of a sheet medium. The sheet medium is a recording medium shaped like a sheet on which an image is formed. The sheet medium includes a recording medium such as paper or the like. 
     In the description of the copying machine  1 , a secondary scanning direction X illustrated in  FIG. 1  is also denoted as a “left-right direction” of the copying machine  1 , and a main scanning direction Y (refer to  FIG. 2 ) orthogonal to the secondary scanning direction X is also denoted as a “forward-backward direction” of the copying machine  1 . The vertical direction Z of the copying machine  1  is orthogonal to the secondary scanning direction X and the main scanning direction Y. 
     Firstly, the image reading device  300  will be described. 
     As illustrated in  FIG. 1 , the image reading device  300  includes an image reading unit  301  and a document feed unit  70 . The image reading unit  301  reads an image of a document G. The document feed unit  70  is disposed above the image reading unit  301 , and conveys the document G to the image reading unit  301 . 
     The document feed unit  70  is openably and closably connected to the image reading unit  301  by a connecting part (not illustrated). An upper side of the document feed unit  70  includes a document mounting part  71 . The document feed unit  70  includes a feed roller (not illustrated) inside of it. 
     Next, respective portions of the main cabinet M will be described making reference to  FIG. 1 . 
     The main cabinet M includes an image forming unit GK and a paper feeding/discharging portion KH. The image forming unit GK uses the image information sent from the image reading apparatus  300  to form a toner image on a sheet of paper T that is an example of a sheet medium. The paper feeding/discharging portion KH feeds a sheet of paper T to the image forming unit GK and discharges the sheet of paper T on which a toner image is formed. 
     The outer shape of the main cabinet M is configured by a case member BD serving as a housing. 
     As illustrated in  FIG. 1 , the image forming unit GK is disposed inside the case member BD. The image forming unit GK includes photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d  as image bearing members (photoreceptors), charging portions  10   a ,  10   b ,  10   c , and  10   d , laser scanner units  4   a ,  4   b ,  4   c , and  4   d  as exposure units, developing units  16   a ,  16   b ,  16   c , and  16   d , toner cartridges  5   a ,  5   b ,  5   c , and  5   d , toner feeding portions  6   a ,  6   b ,  6   c , and  6   d , drum cleaning portions  11   a ,  11   b ,  11   c , and  11   d , static eliminators  12   a ,  12   b ,  12   c , and  12   d , an intermediate transfer belt  7 , primary transfer rollers  37   a ,  37   b ,  37   c , and  37   d , a secondary transfer roller  8 , an opposing roller  18 , and a fixing unit  9 . 
     The paper feeding/discharging portion KH includes a paper feeding cassette  52 , a manual feeding portion  64 , a paper path L for a sheet of paper T, a pair of registration rollers  80 , a first discharging portion  50   a , and a second discharging portion  50   b . It should be noted that the paper path L is an assembly of a first paper path L 1 , a second paper path L 2 , a third paper path L 3 , a manual paper path La, a reverse paper path Lb, and a fourth paper path L 4  as described hereafter. 
     Constituent components of the image forming unit GK and the paper feeding/discharging portion KH will be described in detail hereinafter with reference to  FIG. 1 . 
     First, a description is provided for the image forming unit GK. 
     In the image forming unit GK, such operations are performed in sequence on surfaces of the photoreceptor drums  2   a ,  2   b ,  2   c  and  2   d  in sequence from upstream to downstream as charging by the charging portions  10   a ,  10   b ,  10   c  and  10   d , exposure by the laser scanner units  4   a ,  4   b ,  4   c  and  4   d , development by the developing units  16   a ,  16   b ,  16   c  and  16   d , primary transfer by the intermediate transfer belt  7  and the primary transfer rollers  37   a ,  37   b ,  37   c  and  37   d , static elimination by the static eliminators  12   a ,  12   b ,  12   c  and  12   d , and cleaning by the drum cleaning portions  11   a ,  11   b ,  11   c  and  11   d.    
     In addition, secondary transfer by the intermediate transfer belt  7 , the secondary transfer roller  8  and the opposing roller  18 , and fixation by the fixing unit  9  are performed in the image forming unit GK. 
     Each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d  is composed of a cylindrically shaped member and functions as a photoreceptor or an image bearing member. Each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d  is disposed so as to be rotatable in a direction of an arrow, about a rotational axis that extends in a direction orthogonal to a direction of movement of the intermediate transfer belt  7 . An electrostatic latent image is formed on a surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d.    
     Each of the charging portions  10   a ,  10   b ,  10   c , and  10   d  is disposed so as to face the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d . Each of the charging portions  10   a ,  10   b ,  10   c , and  10   d  applies a uniform negative charge (negative polarity) or positive charge (positive polarity) to the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d.    
     Each of the laser scanner units  4   a ,  4   b ,  4   c , and  4   d  functions as an exposure unit and is spaced apart from the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d . Each of the laser scanner units  4   a ,  4   b ,  4   c , and  4   d  is configured to include a laser light source, a polygonal mirror, a polygonal mirror driving motor and the like, which are not illustrated. 
     Each of the laser scanner units  4   a ,  4   b ,  4   c ,  4   d  scans and exposes the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c ,  2   d  based on the image information related to the image read by the image reading unit  301 . An electric charge of an exposed part of the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d  is removed by scanning and exposing performed by each of the laser scanner units  4   a ,  4   b ,  4   c , and  4   d . In this way, an electrostatic latent image is formed on the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d.    
     The developing units  16   a ,  16   b ,  16   c , and  16   d  are respectively disposed to correspond to the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d , and are disposed to face the corresponding surfaces of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d . Each of the developing units  16   a ,  16   b ,  16   c , and  16   d  forms a color toner image on the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d  by depositing toner of each color on the electrostatic latent image formed on the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d . The respective developing units  16   a ,  16   b ,  16   c , and  16   d  correspond to four colors of yellow, cyan, magenta, and black. Each of the developing units  16   a ,  16   b ,  16   c , and  16   d  is configured to include a developing roller disposed to face the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d , an agitating roller for agitating toner, and the like. 
     The toner cartridges  5   a ,  5   b ,  5   c , and  5   d  are provided to correspond to the developing units  16   a ,  16   b ,  16   c , and  16   d , respectively. The respective toner cartridges  5   a ,  5   b ,  5   c , and  5   d  store the toner of different colors supplied to the respective developing units  16   a ,  16   b ,  16   c , and  16   d . The toner cartridges  5   a ,  5   b ,  5   c , and  5   d  store yellow toner, cyan toner, magenta toner, and black toner, respectively. 
     The toner feeding parts  6   a ,  6   b ,  6   c  and  6   d  are provided to correspond to the toner cartridges  5   a ,  5   b ,  5   c  and  5   d  and the developing units  16   a ,  16   b ,  16   c  and  16   d  respectively, and supply toner of the respective colors stored in the toner cartridges  5   a ,  5   b ,  5   c , and  5   d  to the developing units  16   a ,  16   b ,  16   c , and  16   d , respectively. Each of the toner feeding devices  6   a ,  6   b ,  6   c , and  6   d  is connected with each of the developing units  16   a ,  16   b ,  16   c , and  16   d  via a toner feeding path (not illustrated). 
     Toner images of respective colors formed on the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d  undergo primary transfer in sequence onto the intermediate transfer belt  7 . The intermediate transfer belt  7  is stretched around a driven roller  35 , the opposing roller  18  of a driving roller, a tension roller  36  and the like. Since the tension roller  36  biases the intermediate transfer belt  7  from inside to outside, a predetermined tension is applied to the intermediate transfer belt  7 . 
     Each of the primary transfer rollers  37   a ,  37   b ,  37   c , and  37   d  is disposed opposite to each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d  across the intermediate transfer belt  7 . 
     Predetermined parts of the intermediate transfer belt  7  are nipped between the respective primary image transfer rollers  37   a ,  37   b ,  37   c , and  37   d  and the respective photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d . Each of the predetermined nipped parts is pressed against the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d . Primary transfer nips N 1   a , N 1   b , N 1   c , and N 1   d  are formed between the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d  and the primary image transfer rollers  37   a ,  37   b ,  37   c , and  37   d , respectively. At the respective primary transfer nips N 1   a , N 1   b , N 1   c , and N 1   d , toner images of the respective colors developed on the respective photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d  undergo primary transfer in sequence onto the intermediate transfer belt  7 . In this manner, a full-color toner image is formed on the intermediate transfer belt  7 . 
     A primary transfer bias is applied to each of the primary transfer rollers  37   a ,  37   b ,  37   c , and  37   d  by a primary transfer bias application portion (not illustrated). The primary transfer bias applied by the primary transfer bias application portion causes the toner image of each color formed on each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d  to be transferred onto the intermediate transfer belt  7 . 
     Each of the static eliminators  12   a ,  12   b ,  12   c , and  12   d  is disposed so as to face the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d . Each of the static eliminators  12   a ,  12   b ,  12   c , and  12   d  illuminates light on the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d . In this manner, each of the static eliminators  12   a ,  12   b ,  12   c , and  12   d  removes charge (eliminates an electrical charge) from the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d  after the primary transfer. 
     Each of the drum cleaning portions  11   a ,  11   b ,  11   c , and  11   d  is disposed so as to face the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d . Each of the drum cleaning portions  11   a ,  11   b ,  11   c , and  11   d  removes toner and attached matter remaining on the surface of each of the photoreceptor drums  2   a ,  2   b ,  2   c , and  2   d , and conveys the removed toner to a predetermined collection mechanism for collection. 
     The secondary transfer roller  8  executes secondary transfer of the full-color toner image, which has been primarily transferred to the intermediate transfer belt  7 , to a sheet of paper T. A secondary transfer bias is applied to the secondary transfer roller  8  by a secondary transfer bias application part (not illustrated). The secondary transfer bias is applied by the secondary transfer bias application part transfers the full-color toner image formed on the intermediate transfer belt  7  to the sheet of paper T. 
     The secondary transfer roller  8  comes in contact with and separates from the intermediate transfer belt  7 . More specifically, the secondary transfer roller  8  is configured to be movable between a contact position in contact with the intermediate transfer belt  7  and a separated position separated from the intermediate transfer belt  7 . In particular, the secondary transfer roller  8  is disposed at the contact position when the full color toner image, which has been primarily transferred to a surface of the intermediate transfer belt  7 , is secondarily transferred to the sheet of paper T, and otherwise is disposed at the separated position. 
     The opposing roller  18  is disposed opposite to the secondary transfer roller  8  across the intermediate transfer belt  7 . A predetermined part of the intermediate transfer belt  7  is nipped between the secondary transfer roller  8  and the opposing roller  18 . The sheet of paper T is pressed against an outer surface (a surface to which the toner image is primarily transferred) of the intermediate transfer belt  7 . A secondary transfer nip N 2  is formed between the intermediate transfer belt  7  and the secondary transfer roller  8 . At the secondary transfer nip N 2 , the full-color toner image primarily transferred to the intermediate transfer belt  7  is secondarily transferred to the sheet of paper T. 
     The fixing unit  9  fuses and pressurizes toners of respective colors in order to fix the toners on the sheet of paper T. The toners of respective colors make up the toner image that is secondarily transferred onto the sheet of paper T. The fixing unit  9  includes a heating rotator  9   a  heated by a heater, and a pressurizing rotator  9   b  that is brought into pressure-contact with the heating rotator  9   a . The heating rotator  9   a  and the pressurizing rotator  9   b  nip and compress the sheet of paper T to which the toner image is secondarily transferred, and then convey the sheet of paper T. The sheet of paper T is conveyed while nipped between the heating rotator  9   a  and the pressurizing rotator  9   b . In this manner, the toner transferred to the sheet of paper T is fused and pressurized and thereby fixed to the sheet of paper T. 
     Next, the paper feeding/discharging portion KH will be described. 
     As shown in  FIG. 1 , two paper feeding cassettes  52  as units for housing sheets of paper T are disposed one above the other in a lower part of the main cabinet M. The paper feeding cassettes  52  are mounted on the case member BD, which is a housing of the main cabinet M, so as to be insertable and drawable in a forward horizontal direction. In other words, the paper feeding cassettes  52  house the sheets of paper T and are mounted on the case member BD so as to be insertable and drawable. 
     Each of the paper feeding cassettes  52  includes a paper tray  60  on which the sheets of paper T are placed. Each of the paper feeding cassettes  52  stores the sheets of paper T stacked on the paper tray  60 . The sheets of paper T placed on paper trays  60  are fed out to the paper path L by cassette feeding portions  51 . Each of the cassette feeding portions  51  is disposed on an end portion of each of the paper feeding cassettes  52  on a side for feeding paper (in a right end portion of  FIG. 1 ). 
     Each of the cassette feeding portions  51  includes a double feed preventing mechanism composed of a forward feed roller  61  and a pair of feeding rollers  63 . The forward feed roller  61  is for picking up a sheet of paper T on the paper tray  60 . The pair of feeding rollers  63  is for feeding the sheets of paper T one sheet at a time to the paper path L. 
     The manual feeding portion  64  is provided on a right side face (right in  FIG. 1 ) of the main cabinet M. The manual feeding portion  64  is provided primarily for feeding sheets of paper T that are different in size or type from sheets of paper T stored in the paper feeding cassettes  52  to the main cabinet M. The manual feeding portion  64  includes a manual feeding tray  65  and a paper feeding roller  66 . The manual feeding tray  65  while being closed makes up a portion of a right side face of the main cabinet M. A lower end of the manual feeding tray  65  is rotatably attached (freely openable and closable) to the main cabinet M in the vicinity of the paper feeding roller  66 . A sheet or sheets of paper T are placed on the manual feeding tray  65  while being opened. The paper feeding roller  66  feeds a sheet of paper T placed on the manual feeding tray  65  while being opened to the manual feeding path La. 
     The first discharging portion  50   a  and the second discharging portion  50   b  are provided at a position on an upper side in the main cabinet M and below the image reading unit  301 . The first discharging portion  50   a  and the second discharging portion  50   b  discharge a sheet of paper T on which an image has been formed by the image forming unit GK to the outside of the main cabinet M. The first discharging portion  50   a  and the second discharging portion  50   b  will be described later in detail. 
     The paper path L includes the first paper path L 1 , second paper path L 2 , third paper path L 3 , manual paper path La, reverse paper path Lb and fourth paper path L 4 . The first paper path L 1  is a feed path from the cassette feeding portions  51  to the secondary transfer nip N 2 . The second paper path L 2  is a feed path from the secondary transfer nip N 2  to the fixing unit  9 . The third paper path L 3  is a feed path from the fixing unit  9  to the first discharging portion  50   a . The manual paper path La is a feed path that guides a sheet of paper T supplied from the manual feeding portion  64  to the first paper path L 1 . The reverse paper path Lb is a feed path that turns over the front and back sides of a sheet of paper T that is conveyed from upstream to downstream in the third paper path L 3  and returns the sheet of paper T to the first paper path L 1 . 
     The third paper path L 3  is a feed path that conveys a sheet of paper T from the image forming unit GK to the first discharging portion  50   a  (described below). The reverse paper path Lb branches from the third path L 3 . The fourth paper path L 4  is a feed path for conveying a sheet of paper T, which is being conveyed in the third paper path L 3 , to the second discharging portion  50   b.    
     In addition, a first junction P 1  and a second junction P 2  are provided midway in the first paper path L 1 . A first branch portion Q 1  is provided midway in the third paper path L 3 . 
     The first junction P 1  is where the manual paper path La merges with the first paper path L 1 . The second junction P 2  is where the reverse paper path Lb merges with the first paper path L 1 . 
     The first branch portion Q 1  is where the fourth paper path L 4  branches off from the third paper path L 3 . A branching member  58  is provided at the first branch portion Q 1 . The branching member  58  switches a feeding direction of a sheet of paper T discharged from the fixing unit  9  to the third paper path L 3  leading to the first discharging portion  50   a  or to the fourth paper path L 4  leading to the second discharging portion  50   b.    
     In addition, a sensor and the pair of registration rollers  80  are disposed midway in the first paper path L 1  (more specifically, between the second junction P 2  and the secondary transfer roller  8 ). The sensor detects a sheet of paper T. The sensor is disposed immediately in front of the pair of registration rollers  80  in a direction of conveying the sheet of paper T (upstream of the conveying direction). The pair of registration rollers  80  adjusts the timing between feeding the sheet of paper T and forming a toner image in the image forming unit GK, and the correction of skew (paper inclination) of the sheet of paper T. The pair of registration rollers  80  conveys the sheet of paper T through correction and timing adjustment as described above based on the detection signal information from the sensor. 
     The reverse paper path Lb is a paper path where one surface (unprinted surface) opposite to another surface that has already been printed is set to face the intermediate transfer belt  7 , when duplex printing of a sheet of paper T is performed. The reverse paper path Lb can turn over and return a sheet of paper T, which has been conveyed from the first branch portion Q 1  toward the first discharging portion  50   a  or the second discharging portion  50   b , to the first paper path L 1 , in order to convey the sheet of paper T to upstream of the pair of registration rollers  80  disposed upstream of the secondary transfer roller  8 . When a sheet of paper T is conveyed from the first branch portion Q 1  to the first discharging portion  50   a , the reverse paper path Lb conveys the sheet of paper T, which has been turned over by a pair of discharging and reversing rollers  55  (described below) provided at the first discharging portion  50   a , to the image forming unit GK. In the secondary transfer nip N 2 , a predetermined toner image is transferred to the unprinted surface of the sheet of paper T that has been turned over by the reverse paper path Lb. 
     The first discharging portion  50   a  is formed at an end portion of the third paper path L 3  as a discharging portion. The first discharging portion  50   a  discharges a sheet of paper T, which does not require post-processing, to outside the main cabinet M. As shown in  FIG. 1 , the first discharging portion  50   a  is disposed at a position on an upper side in the main cabinet M and below the image reading unit  301 . In addition, the first discharging portion  50   a  has an opening toward a left side face of the main cabinet M (left side in  FIG. 1 ) and is disposed towards a right side face of the main cabinet M. A stacking space portion  540  described below is formed on an opened side of the first discharging portion  50   a.    
     The pair of discharging and reversing rollers  55  is provided at the first discharging portion  50   a . The pair of discharging and reversing rollers  55  has the function of completely discharging a sheet of paper T conveyed in the third paper path L 3  from the first discharging portion  50   a  to the stacking space portion  540  (described below). In addition, the pair of discharging and reversing rollers  55  has the function of a reversing portion (for switchback) that partially feeds out a sheet of paper T from the first discharging portion  50   a  to the stacking space portion  540  (described below) and turns over the sheet of paper T, which has been conveyed in the third paper path L 3 . In this manner, the pair of discharging and reversing rollers  55  has not only the function of completely discharging the sheet of paper T to the stacking space portion  540  (described below) but also the function of a reversing unit. When the pair of discharging and reversing rollers  55  exhibits the function of a reversing unit, the pair of discharging and reversing rollers  55  is termed a “switchback roller pair.” 
     As illustrated in  FIG. 1 , the inner accumulating portion  510  as a stacking unit is disposed below the image reading unit  301 . Sheets of paper T discharged from the first ejection unit  50   a  are stacked in the inner accumulating portion  510 . A pressing member  200  is disposed in the stacking space portion  540  (described below) of the inner accumulating portion  510 . The pressing member  200  is disposed in contact with an upper surface of a sheet of paper T stacked on the stacking surface portion  520 . 
     The details of the inner accumulating portion  510  and the pressing member  200  will be described below. 
     The second discharging portion  50   b  is formed on an end (downstream in the feed direction) of the fourth paper path L 4 . The second discharging portion  50   b  is formed to open towards the left side face of the main cabinet M below the first discharging portion  50   a  (left side of  FIG. 1 ). The second discharging portion  50   b  is a discharging portion for post-processing (or a discharging portion for a relay unit  500 ) that feeds out a sheet of paper T, which has been conveyed to the fourth paper path L 4 , to a post-processing device  600  via the relay unit  500  (described below). 
     Sensors for paper detection are disposed at predetermined positions in the respective paper paths. 
     The relay unit  500  is disposed continuously with the main cabinet M (connected to the main cabinet M) on an open side of the second discharging portion  50   b . The relay unit  500  is attached to the main cabinet M in contact with the stacking space portion  540  below the image reading unit  301 . An upper surface of the relay unit  500  is configured as the stacking surface portion  520  for stacking sheets of paper T discharged from the first discharging portion  50   a . The post-processing device  600  is disposed continuously with the relay unit  500  (connected to the main cabinet M). 
     The post-processing device  600  executes post-processing on the sheets of paper T (stapling, punching, sorting, and the like). The sheets of paper T are subjected to post-processing, which have been discharged from the second discharging portion  50   b  of the main cabinet M, and conveyed to the post-processing device  600  via an inner paper path  551  of the relay unit  500 . The post-processing device  600  is detachably mounted on a left surface  441  of the main cabinet M. The post-processing device  600  includes a discharged paper tray  660 . The discharged paper tray  660  accumulates sheets of paper T discharged from a discharging portion (not illustrated) of the post-processing device  600 . 
     When post-processing is not required, the copying machine  1  in the present embodiment may set the paper ejection destination (paper path route) for a sheet of paper T after completion of image formation in the image forming unit GK to the following two options. 
     A first option is a setting in which although a sheet of paper T is sent to the post-processing device  600  from the fourth paper path L 4  through the relay unit  500 , the post-processing device  600  is set to discharge the sheet of paper T to the discharged paper tray  660  without executing post-processing. 
     A second option is a setting in which the copying machine  1  discharges a sheet of paper T from the first discharging portion  50   a  at the end of the third paper path L 3  to the inner accumulation unit  510  without sending the sheet of paper T to the fourth paper path L 4 . The sheet of paper T discharged from the first discharging portion  50   a  to the inner accumulation unit  510  is accumulated on the stacking surface portion  520  that is the upper surface of the relay unit  500 . The sheet of paper T accumulated on the stacking surface portion  520  is removed on a front side of the main cabinet M. 
     A structure will be briefly described below for eliminating a paper jam (JAM) in main paper paths L 1  to L 3  (the first paper path L 1 , the second paper path L 2 , and the third paper path L 3  are also collectively referred to as “main paper paths” hereinafter), and in the reverse paper path Lb. 
     As shown in  FIG. 1 , the main paper paths L 1  to L 3  and the reverse paper path Lb are disposed to extend in parallel in a substantially perpendicular direction on a right lateral face side of the main cabinet M (right side in  FIG. 1 ). A cover assembly  40  is provided on a right side face of the main cabinet M (right side in  FIG. 1 ) to constitute a part of the side face of the main cabinet M. A lower end portion of the cover assembly  40  is connected with the main cabinet M via a fulcrum shaft  43 . An axial direction of the fulcrum shaft  43  is disposed along a direction intersecting the main paper paths L 1  to L 3  and the reverse paper path Lb. The cover assembly  40  is pivotally configured about the fulcrum shaft  43  between a closed position (illustrated in  FIG. 1 ) and an opened position (not illustrated). 
     The cover assembly  40  is composed of a first cover  41  and a second cover  42 . The first cover  41  is pivotally connected with the main cabinet M by the fulcrum shaft  43 . The second cover  42  is pivotally connected with the main cabinet M by the fulcrum shaft  43  in a similar manner to the first cover  41 . The first cover  41  is positioned more outward (to a lateral face side) than the second cover  42  in the main cabinet M. It should be noted that the first cover  41  is illustrated as the part hatched with falling diagonal broken lines in  FIG. 1  from top left to bottom right. The second cover  42  is illustrated as the part hatched with falling diagonal broken lines from top right to bottom left. 
     In a state where the cover assembly  40  is in a closed position, an outer face of the first cover  41  constitutes a portion of an outer face (side face) of the main cabinet M. 
     In addition, in a state in which the cover assembly  40  is in the closed position, an inner face (facing inside the main cabinet M) of the second cover  42  constitutes a portion of the main paper paths L 1  to L 3 . 
     Furthermore, in a state where the cover assembly  40  is in the closed position, an inner face of the first cover  41  and an outer face of the second cover  42  constitute at least a portion of the reverse paper path Lb. In other words, the reverse paper path Lb is formed between the first cover  41  and the second cover  42 . 
     Since the copy machine  1  according to the present embodiment is provided with the cover assembly  40  having the above configuration, a sheet of jammed paper in the main paper paths L 1  to L 3  can be removed by pivoting the cover assembly  40  from the closed position shown in  FIG. 1  to an opened position (not shown) so as to allow the main paper paths L 1  to L 3  to be exposed, when a paper jam (JAM) occurs in the main paper paths L 1  to L 3 . On the other hand, when a paper jam occurs in the reverse paper path Lb, a sheet of jammed paper in the reverse paper path Lb can be removed by pivoting the cover assembly  40  to the opened position and then pivoting the second cover  42  about the fulcrum shaft  43  toward the main cabinet M (left side in  FIG. 1 ) so as to allow the reverse paper path Lb to be exposed. 
     Next, the configuration related to the inner accumulation portion  510  and the pressing member  200  that are characteristic portions of the present disclosure will be described in detail with reference to  FIGS. 2 to 5 .  FIG. 2  is a side view illustrating the configuration of the pressing member  200  and the inner accumulating portion  510  according to the first embodiment.  FIG. 3  is a perspective view illustrating the configuration of the pressing member  200  and the stacking surface portion  520  according to the first embodiment.  FIG. 4  is a perspective view illustrating the configuration of the stacking surface portion  520  according to the first embodiment.  FIG. 5  is a side view illustrating an enlargement of the pressing member  200  in  FIG. 2 . 
     In the present embodiment, a direction in which a sheet of paper T conveyed by the pair of discharging and reversing rollers  55  is discharged from the first discharging portion  50   a  towards the inner accumulation portion  510  is termed a “discharging direction D 1 .” The “discharging direction D 1 ” substantially corresponds to a direction from the first discharging portion  50   a  towards the inner accumulation portion  510  in the secondary scanning direction X. Furthermore, a direction opposite to the discharging direction D 1  is termed a “return direction D 2 ,” in which a sheet of paper T partially fed out to the stacking space portion  540  is returned from the inner accumulation portion  510  to the discharging portion  50   a  by the pair of discharging and reversing rollers  55 . The “return direction D 2 ” substantially corresponds to a direction from the inner accumulation portion  510  towards the first discharging portion  50   a  in the secondary scanning direction X. A direction orthogonal to the discharging direction D 1  and the return direction D 2  is termed a “paper width direction W,” which is oriented along a sheet of paper T that is stacked on the stacking surface portion  520 . The “paper width direction W” substantially corresponds to the main scanning direction Y. 
     As illustrated in  FIGS. 2 and 3 , the inner accumulation portion  510  includes a stacking surface portion  520 , a stacking top surface portion  530  as an upper surface portion, a stacking space portion  540 , and a restriction wall  550  as a restriction portion. 
     The stacking surface portion  520  is disposed at a lower portion in the vertical direction Z in the inner accumulation portion  510 . A sheet of paper T on which a predetermined toner image has been formed and that has been discharged from the first discharging portion  50   a  is stacked on the stacking surface portion  520 . An upper surface of the relay unit  500  is utilized for the stacking surface portion  520 . 
     As illustrated in  FIGS. 2 and 4 , the stacking surface portion  520  is configured to include a planar portion  521  and a plurality of protruding portions  522 . 
     The planar portion  521  is formed as a horizontal surface. The plurality of protruding portions  522  is formed to project upward from the planar portion  521  in the vertical direction Z. Each protruding portion  522  is formed in a shape of a ridge having a top when viewed in the paper width direction W. 
     The plurality of protruding portions  522  is composed of three first protruding portions  523 , three second protruding portions  524  and one third protruding portion  525 . The three first protruding portions  523  and the three second protruding portions  524  have substantially the same height. Furthermore, the one third protruding portion  525  has a height that is lower than the three first protruding portions  523  and the three second protruding portions  524 . 
     The three first protruding portions  523  have substantially the same shape when viewed in the paper width direction W. The three first protruding portions  523  are arranged spaced in series in the paper width direction W and more upstream than the center of the stacking surface portion  520  in the discharging direction D 1 . The three first protruding portions  523  include one first protruding portion  523  that is formed at the center of the stacking surface portion  520  in the paper width direction W and two first protruding portions  523  that are arranged spaced on both sides of the one first protruding portion  523 . 
     Each of the three first protruding portions  523  includes a first upward slope  523 A and a first downward slope  523 B. The first upward slope  523 A is formed upstream in the discharging direction D 1 . The first downward slope  523 B is formed downstream in the discharging direction D 1 . 
     The first upward slope  523 A inclines upwardly from upstream to downstream in the discharging direction D 1 . An angle of the first upward slope  523 A to the planar portion  521  is determined so that a sheet of paper T discharged in the discharging direction D 1  is conveyed without interference. 
     The first downward slope  523 B is formed continuously with the first upward slope  523 A through a smooth curved surface in proximity to the top of the first protruding portion  523 . The first downward slope  523 B inclines downwardly from upstream to downstream in the discharging direction D 1 . An angle of the first downward slope  523 B to the planar portion  521  is determined greater than the inclination angle of the first upward slope  523 A. 
     The three second protruding portions  524  have substantially the same shape when viewed in the paper width direction W. The three second protruding portion  524  are disposed in series in the paper width direction W and in proximity to an end portion of the stacking surface portion  520  downstream in the discharging direction D 1 . The three second protruding portions  524  includes one second protruding portion  524  that is formed adjacent to one end of the stacking surface portion  520  in the paper width direction W and two other second protruding portions  524  spaced in series at respective predetermined distances from the one second protruding portion  524  in the paper width direction W. 
     Each of the respective three second protruding portions  524  includes a second upward slope  524 A and a second downward slope  524 B. The second upward slope  524 A is formed upstream in the discharging direction D 1 . The second downward slope  524 B is formed downstream in the discharging direction D 1 . 
     The second upward slope  524 A inclines upwardly from the upstream to downstream in the discharging direction D 1 . An angle of the second upward slope  524 A to the planar portion  521  is determined so that a sheet of paper T discharged in the discharging direction D 1  is conveyed without interference. 
     The second downward slope  524 B is connected with the second upward slope  524 A in proximity to the top of the second protruding portion  524 . The second downward slope  524 B inclines downwardly from upstream to downstream. An angle of the second downward slope  524 B to the planar portion  521  is determined greater than the inclination angle of the second upward slope  524 A. The second downward slope  524 B is disposed in proximity to the restriction wall  550 , and faces the restriction wall  550 . 
     The one third protruding portion  525  is disposed more upstream than a downstream end of the stacking surface portion  520  in the discharging direction D 1 . The one third protruding portion  525  is disposed in proximity to another end of the stacking surface portion  520  in the paper width direction W. The third protruding portion  525  includes a third upward slope  525 A and a third downward slope  525 B. The third upward slope  525 A is formed upstream in the discharging direction D 1 . The third downward slope  525 B is formed downstream in the discharging direction D 1 . 
     The restriction wall  550  restricts sheets of paper T stacked on the stacking surface portion  520  from moving in the discharging direction D 1 . As illustrated in  FIG. 2 , the restriction wall  550  is formed to extend upwardly in the vertical direction Z from the vicinity of an outer edge of the stacking surface portion  520  (the left side of the main cabinet M in  FIG. 1 ), downstream in the discharging direction D 1 . The restriction wall  550  faces the distal end of a sheet of paper T stacked on the stacking surface portion  520  in the discharging direction D 1 . In this manner, the restriction wall  550  controls the position of the distal end of a sheet of paper T discharged from the first discharging portion  50   a , thereby restricting the sheet of paper T from moving towards downstream in the discharging direction D 1 . 
     The stacking surface portion  520  includes a surface area that enables stacking of a sheet of paper T of maximum size. 
     A virtual surface is assumed for the stacking surface portion  520 . The virtual surface is a flat surface under the assumption that there is not the plurality of protruding portions  522  (the first protruding portion  523 , the second protruding portion  524 , and the third protruding portion  525 ). With respect to the stacking surface portion  520  according to the present embodiment, the length from an end of the virtual surface on a side closer to the first discharging portion  50   a  to the restriction wall  550  is less than the length of the sheet of paper T of maximum size in the discharging direction D 1 . Consequently, when the sheet of paper T of maximum size is stacked on the stacking surface portion  520  in parallel with the virtual surface, the sheet of paper T of maximum size cannot be stacked on the stacking surface portion  520 . 
     The length along a surface from the end of the stacking surface portion  520  including the plurality of protruding portions  522  on the side closer to the first discharging portion  50   a  to the restriction wall  550  is equal to or greater than the length of the sheet of paper T of maximum size in the discharging direction D 1 . In this configuration, the stacking surface portion  520  enables stacking of the sheet of paper T of maximum size having a greater length in the discharging direction D 1  than the virtual surface (the surface without the plurality of protruding portions  522  on the stacking surface portion  520 ). 
     For example, when the sheet of paper T of maximum size is a size A3, the length of the surface of the stacking surface portion  520  including the plurality of protruding portions  522  in the discharging direction D 1  is set to be equal to or greater than the length of the longer side of a sheet of A3 size paper. The length of the surface of the stacking surface portion  520  in the paper width direction W is set to be equal to or greater than the length of the shorter side of the sheet of A3 size paper. In the present embodiment, when a sheet of A3 size paper T is discharged while the longer side of the sheet of A3 size paper is in parallel with the discharging direction D 1 , the sheet of A3 size paper T is termed a “sheet of A3 vertical paper T.” 
     The stacking top surface portion  530  is spaced a predetermined distance upward from and disposed opposite to the stacking surface portion  520  in the vertical direction Z. A surface of the lower portion of the image reading unit  301  is utilized for the stacking top surface portion  530 , which is configured to be flat. 
     The stacking space portion  540  is between the stacking surface portion  520  and the stacking top surface portion  530 . A sheet of paper T discharged from the first discharging portion  50   a  is guided into the stacking space portion  540 . The stacking space portion  540  is where sheets of paper T stacked on the stacking surface portion  520  are housed. 
     Furthermore, the stacking space portion  540  has a front aperture that opens onto outside the front surface of the main cabinet M. The sheets of paper T stacked on the stacking surface portion  520  can be removed through the front aperture of the main cabinet M. That is to say, the stacking space portion  540  of the copying machine  1  in the present embodiment is formed as a recessed portion of the main cabinet M under the image reading unit  301 . Consequently, the copying machine  1  according to the present embodiment is termed a so-called copying machine of paper discharged inside a cabinet. 
     As illustrated in  FIG. 2 , a pressing member  200  is disposed in the stacking space portion  540 . 
     The pressing member  200  includes a plate portion. When viewed in the paper width direction W, the plate portion of the pressing member  200  is formed flat to extend from the stacking top surface portion  530  towards the stacking surface portion  520 . 
     A base portion  201  of the pressing member  200  (one end of the pressing member  200 ) is attached rotatably to the stacking top surface portion  530  (the lower surface of the image reading unit  301 ) through a mounting member  210 . 
     A distal end portion  202  of the pressing member  200  (another end of the pressing member  200 ) is configured as a free end. The distal end portion  202  of the pressing member  200  is disposed in contact with the upper surface of the uppermost sheet of sheets of paper T stacked in the stacking surface portion  520 . The pressing member  200  comes in contact with the uppermost sheet of paper T due to its self weight at the distal end portion  202  and applies weight to the sheets of paper T. 
     “The upper surface of the uppermost sheet of the sheets of paper T stacked in the stacking surface portion  520 ” in the following description is also referred to as “an uppermost surface of the sheets of paper T stacked in the stacking surface portion  520 .” 
     A flat plane connecting the base portion  201  and the distal end portion  202  of the pressing member  200  is inclined so that the distal end portion  202  is positioned more distant from the first discharging portion  50   a  (downstream in the discharging direction D 1 ) than the base portion  201  relative to the upper surface of the sheet of paper T stacked on the stacking surface portion  520 . 
     As illustrated in  FIGS. 2 and 3 , the pressing member  200  is disposed in contact with the upper surface of the sheet of paper T stacked on the stacking surface portion  520  in proximity to the center of the discharging direction D 1 . 
     Furthermore, the pressing member  200  is disposed in contact with the upper surface of the sheet of paper T stacked on the stacking surface portion  520 , in proximity to the first protruding portion  523  and more downstream than the first protruding portion  523  in the discharging direction D 1 . The pressing member  200  is disposed in contact with the upper surface of the sheet of paper T stacked on the stacking surface portion  520 , while deforming the sheet of paper T along the first protruding portion  523 , compared with a state in which the pressing member  200  is not contact with the upper surface of the sheet of paper T stacked on the stacking surface portion  520 . It may not be necessary for the pressing member  200  to deform the sheet of paper T stacked on the stacking surface portion  520  to be completely deformed along the first protruding portion  523 . The pressing member  200  may deform the sheet of paper T along the first protruding portion  523 . 
     As illustrated in  FIG. 3 , the pressing member  200  is disposed in contact with the upper surface of the sheet of paper T stacked on the stacking surface portion  520  in proximity to the center of the paper width direction W. 
     The pressing member  200  is formed substantially rectangular when viewed along the thickness direction. The distal end portion  202  of the pressing member  200  is curved opposite to the first discharging portion  50   a . In the pressing member  200 , a portion of the distal portion  202  that is in contact with a sheet of paper T is configured as a flat surface that has a predetermined length in the paper width direction W. 
     The pressing member  200  described above allows a sheet of paper T to move to be stacked on the stacking surface portion  520  by rotating so that the distal end portion  202  moves in a direction opposite to the first discharging portion  50   a . The pressing member  200  comes in contact with the upper surface of the sheet of paper T that is allowed to move in the direction opposite to the first discharging portion  50   a , and deforms this sheet of paper T along the first protruding portion  523 . 
     The above operation may be realized by suitably setting the angle of the pressing member  200  relative to the sheet of paper T stacked on the stacking surface portion  520  and the weight applied to this sheet of paper T. 
     As illustrated in  FIG. 5 , the pressing member  200  further includes a rotation shaft  203  and a mounting projecting portion  205 . 
     The rotation shaft  203  is inserted into a rotation supporting hole  213  of the mounting member  210  (described below). The rotation shaft  203  is formed to project on both outer sides in the paper width direction W at the base portion  201  of the pressing member  200 . The central axis of the rotation shaft  203  extends in the paper width direction W. 
     The mounting projecting portion  205  is configured to engage with a retraction hole  214  of the mounting member  210  (described below). The mounting projecting portion  205  is formed in proximity to the base portion  201  between the base portion  201  and the distal end portion  202  of the pressing member  200 . The mounting projecting portion  205  is formed to project outward from the side surface of the pressing member  200  in the paper width direction W. 
     The mounting member  210  rotatably supports the pressing member  200 . As illustrated in  FIG. 2 , the mounting member  210  is attached to the stacking top surface portion  530 . 
     As illustrated in  FIG. 5 , the mounting member  210  includes a mounting plate portion  211  and a pair of side plate portions  212 . The pair of side plate portions  212  extends from proximity to both end portions of the mounting plate portion  211  in the paper width direction W towards a lower side in the vertical direction Z. The mounting plate portion  211  is a plate portion that is parallel to the stacking top surface portion  530 . The mounting plate portion  211  is attached to the stacking top surface portion  530 . The pair of side plate portions  212  is made of plate portions that are parallel to the discharging direction D 1  and the paper width direction W. The pair of side plate portions  212  is disposed opposite to each other. 
     A pair of rotation supporting holes  213  and a pair of retraction holes  214  penetrating in the paper width direction W are formed respectively in the pair of side plate portions  212  of the mounting member  210 . 
     The rotation shaft  203  of the pressing member  200  is inserted into the rotation supporting hole  213 . The rotation supporting hole  213  accommodates the rotation shaft  203 . The rotation supporting hole  213  rotatably supports the pressing member  200 . Since the rotation shaft  203  of the pressing member  200  is disposed by insertion into the rotation supporting hole  213 , the pressing member  200  comes in contact with the upper surface of the sheet of paper T stacked on the stacking surface portion  520  due to the self weight of the pressing member  200 . 
     The mounting projecting portion  205  of the pressing member  200  can engage with the retraction hole  214 . The retraction hole  214  is formed at a position at which the mounting projecting portion  205  is engaged, in a state in which the pressing member  200  is disposed along the stacking top surface portion  530 . The retraction hole  214  engages with the mounting projecting portion  205  of the pressing member  200 , when the pressing member  200  rotates about the rotation axis of the rotation shaft  203  to be disposed along the lower surface (stacking top surface  530 ) of the image reading unit  301 . 
     Next, the operation of the copying machine  1  according to the present embodiment will be briefly described making reference to  FIG. 1 . 
     The operation of the copying machine  1  will be described for a case where the copying machine is set so that a sheet of paper T is discharged into the inner accumulation portion  510 . 
     In the present embodiment, the operation of the copying machine  1  will be described for a case where printing is performed for a sheet of paper T of A3 vertical-length making reference to  FIGS. 6A to 6G  while describing the operation of the pressing member  200 . 
       FIG. 6A  illustrates the operation of simplex printing and illustrates the configuration when a sheet of paper T starts to be conveyed in the discharging direction D 1 .  FIG. 6B  illustrates the operation of simplex printing in which a sheet of paper T is conveyed along the first protruding portion  523 .  FIG. 6C  illustrates the operation of simplex printing in which a sheet of paper T is in contact with the pressing member  200  in a stiff configuration.  FIG. 6D  illustrates the operation of simplex printing in which the distal end of a sheet of paper T has moved towards the distal end portion  202  of the pressing member  200 .  FIG. 6E  illustrates the operation of simplex printing in which a sheet of paper T has rotated the pressing member  200 .  FIG. 6F  illustrates the operation of simplex printing in which a sheet of paper T has moved in the discharging direction D 1  in contact with the distal end portion  202  of the pressing member  200 .  FIG. 6G  illustrates the operation of simplex printing in which a sheet of paper T is stacked on the stacking surface portion  520  after completion of simplex printing. 
     Firstly, simplex printing of a sheet of paper T of A3 vertical-length stored in the sheet cassette  52  will be described. 
     The sheet of paper T of A3 vertical-length stored in the sheet cassette  52  is fed out to the first paper path L 1  by the forward feed roller  61  and the pair of feeding rollers  63 . Then, the sheet of paper T is conveyed to the pair of registration rollers  80  through the first junction P 1  and the first paper path L 1 . 
     Skew correction of the sheet of paper T and timing adjustment in relation to a toner image are executed in the pair of registration rollers  80 . 
     The sheet of paper T of A3 vertical-length discharged from the pair of registration rollers  80  is introduced between the intermediate transfer belt  7  and the secondary transfer roller  8  (secondary transfer nip N 2 ) through the first paper path L 1 . A toner image is transferred onto the sheet of paper T between the intermediate transfer belt  7  and the secondary transfer roller  8 . 
     Thereafter, the sheet of paper T of A3 vertical-length is discharged between the intermediate transfer belt  7  and the secondary transfer roller  8 . The sheet of paper T discharged between the intermediate transfer belt  7  and the secondary transfer roller  8  is introduced to a fixing nip between the heating rotator  9   a  and the pressurizing rotator  9   b  in the fixing unit  9  through the second paper path L 2 . The toner is fused at the fixing nip and fixed onto the sheet of paper T. 
     Next, the sheet of paper of A3 vertical-length is conveyed to the first discharging portion  50   a  through the third paper path L 3 . The sheet of paper T conveyed to the first discharging portion  50   a  is discharged from the first discharging portion  50   a  to the stacking space portion  540  of the inner accumulation portion  510  by the pair of discharging and reversing rollers  55 . 
     As illustrated in  FIG. 6A , the lower surface of the sheet of paper T discharged from the first discharging portion  50   a  comes into contact with the uppermost surface of sheets of paper T stacked on the stacking surface portion  520 . The sheet of paper T discharged from the first discharging portion  50   a  is conveyed in the discharging direction D 1  in contact with the uppermost surface of the sheets of paper T stacked on the stacking surface portion  520 . 
     Thereafter, the sheet of paper of A3 vertical-length fed out to the stacking space portion  540  is further conveyed in the discharging direction D 1  by the pair of discharging and reversing rollers  55 . As illustrated in  FIG. 6B , the sheet of paper T of A3 vertical-length is conveyed diagonally upward along the first upward slope  523 A of the first protruding portion  523 . 
     As illustrated in  FIG. 6C , the distal end of the sheet of paper T conveyed diagonally upward abuts in a stiff state with the pressing member  200  at a portion that is more upward than the distal end portion  202  on the surface facing the first discharging portion  50   a.    
     As illustrated in  FIG. 6D , since the sheet of paper T moves in the discharging direction D 1 , the distal end of the sheet of paper T abutting with the pressing member  200  moves from a position that is more upward than the distal end portion  202  of the pressing member  200  towards the distal end portion  202  along the surface facing the first discharging portion  50   a . The distal end side of the conveyed sheet of paper T is curved to be upwardly convex. 
     The conveyed sheet of paper T is further conveyed by the pair of discharging and reversing rollers  55 . As illustrated in  FIG. 6E , the sheet of paper T presses the surface facing the first discharging portion  50   a  in the distal end portion  202  of the pressing member  200 . In this manner, the sheet of paper T causes the pressing member  200  to rotate so that the distal end portion  202  of the pressing member  200  moves in the discharging direction D 1  (downstream of the discharging direction D 1 ). 
     Thereafter, the sheet of paper T further conveyed in the discharging direction D 1  enters below the pressing member  200  and passes between the uppermost sheet of the sheets of paper T stacked on the stacking surface portion  520  and the pressing member  200 . The sheet of paper T conveyed in the discharging direction D 1  is conveyed as illustrated in  FIG. 6F  in the discharging direction D 1  in a state in which the upper surface of the sheet of paper T is in contact with the distal end portion  202  of the pressing member  200 . 
     In this manner, the sheet of paper T of A3 vertical-length passes between the stacking surface portion  520  and the pressing member  200  and is conveyed in the discharging direction D 1 . The distal end portion  202  of the pressing member  200  is in contact with the upper surface of the sheet of paper T in proximity to the first protruding portion  523 . Therefore, the pressing member  200  can deform the sheet of paper T of A3 vertical-length, which is conveyed in the discharging direction D 1 , along the first protruding portion  523 . 
     In particular, the pressing member  200  causes the sheet of paper T, which is conveyed diagonally upward by the first upward slope  523 A upstream of the first protruding portion  523 , to come in contact with the pressing member  200  downstream of the first protruding portion  523 . In this manner, the pressing member  200  pushes the sheet of paper T to move along the first downward slope  523 B downstream of the first protruding portion  523 . Accordingly, the pressing member  200  can cause the sheet of paper T stacked on the stacking surface portion  520  to be more deformed along the protruding portion  522 . 
     Thereafter, the sheet of paper T of A3 vertical-length is conveyed in the discharging direction D 1  by the pair of discharging and reversing rollers  55 . The distal end of the sheet of paper T of A3 vertical-length is conveyed diagonally upward along the second upward slope  524 A of the second protruding portion  524  at the downstream end of the stacking surface portion  520  in the discharging direction D 1 . 
     Thereafter, as illustrated in  FIG. 6G , the sheet of paper T of A3 vertical-length that is subjected to simplex printing is stacked at a predetermined position in the discharging direction D 1  on the stacking surface portion  520 . In this manner, simplex printing on the sheet of paper T contained in the sheet cassette  52  is completed. 
     In a state in which the sheet of paper T of A3 vertical-length that is subjected to simplex printing is stacked on the stacking surface portion  520 , the sheet of paper T is deformed to have an upwardly convex projection in proximity to the first protruding portion  523  in the discharging direction D 1 . In addition, the sheet of paper T is deformed to incline upwardly in proximity to the second protruding portion  524 . In this manner, it is possible to implement a configuration in which a sheet of paper T of A3 vertical-length that is the maximum size can be stacked by deforming the sheet of paper T in the vertical direction, without increasing the length of the stacking surface portion  520  in the discharging direction D 1  and the height of the stacking space portion  540  in the vertical direction Z. As a result, it is possible to prevent an increase in the size of the device. 
     Since the second protruding portion  524  is formed adjacent to the end of the stacking surface portion  520 , it is possible to stably deform the distal end of a sheet of paper T to incline upwardly. 
     When simplex printing is executed on a sheet of paper T stacked on the manual tray  65 , the sheet of paper T is fed out to the manual paper path La by the paper feeding roller  66 . Thereafter, the sheet of paper T is conveyed to the pair of registration rollers  80  through the first junction P 1  and the first paper path L 1 . Subsequent operations are the same as those operations for simplex printing of a sheet of paper T that is contained in the sheet cassette  52  as described above, and therefore such description will not be repeated. 
     Next, the operation of the copy machine  1  for duplex printing will be described. 
     When simplex printing is performed, as described above, a sheet of paper T subjected to simplex printing is discharged from the first discharging portion  50   a  to the inner accumulation portion  510 . In this manner, the printing operation is completed. 
     In contrast, when duplex printing is performed, a sheet of paper T that has been subjected to simplex printing is turned over by the pair of discharging and reversing rollers  55  and then re-conveyed back to the pair of registration rollers  80  in a state in which the front and back surfaces are reversed with respect to those during simplex printing. In this manner, duplex printing is performed on the sheet of paper T. 
     More particularly, the operations until the step in which the sheet of paper T that has been simplex printed is conveyed to the first discharging portion  50   a  through the third paper path L 3  are the same as the operations described above in relation to simplex printing. 
     During duplex printing, a sheet of paper T of A3 vertical-length that has been printed on one surface is conveyed to the first discharging portion  50   a . Then, the sheet of paper T of A3 vertical-length is partially fed out from the first discharging portion  50   a  to the stacking space portion  540  of the inner accumulation portion  510  and subsequently turned over by the pair of discharging and reversing rollers  55 . 
     In the present embodiment, when the sheet of paper T of A3 vertical-length is partially fed out and turned over in the stacking space portion  540  by the pair of discharging and reversing rollers  55 , the distal end of the sheet of paper T of A3 vertical-length reaches the pressing member  200 . For this reason, the sheet of paper T conveyed in the discharging direction D 1  passes between the uppermost sheet of sheets of paper T stacked on the stacking surface portion  520  and the pressing member  200  in the same manner as simplex printing as described above. The sheet of paper T is conveyed in the discharging direction D 1  in a state in which the upper surface of the sheet of paper T is in contact with the distal end portion  202  of the pressing member  200 . The operation to this point in duplex printing is the same as the simplex printing, and therefore detailed description will not be repeated. 
     When the sheet of paper T of A3 vertical-length passes between a sheet of paper T stacked on the stacking surface portion  520  and the pressing member  200  and advances by a predetermined distance in the discharging direction D 1 , the conveyance direction is switched to a return direction D 2 . 
     In this manner, the sheet of paper T of A3 vertical-length retained by the pair of discharging and reversing rollers  55  is conveyed in the return direction D 2  by the pair of discharging and reversing rollers  55 . 
     Thereafter, the sheet of paper T of A3 vertical-length conveyed in the return direction D 2  is conveyed in an opposite direction in the third paper path L 3  (the direction from the first discharging portion  50   a  towards the first branch portion Q 1 ). 
     When the sheet of paper T of A3 vertical-length is conveyed in the third paper path L 3  in the opposite direction, the sheet of paper T is guided to the reverse paper path Lb by the branching member  58 . Thereafter, the sheet of paper T is guided into the first paper path L 1  through the second junction P 2 . Herein, the front and back surfaces of the sheet of paper T have been turned over, differing from simplex printing. 
     Furthermore, the sheet of paper T is adjusted and corrected by the pair of registration rollers  80 . The sheet of paper T is guided between the intermediate transfer belt  7  and the secondary transfer roller  8  through the first paper path L 1 . The unprinted surface of the sheet of paper T faces the intermediate transfer belt  7  as a result of passing through the reverse paper path Lb. Accordingly, a toner image is transferred onto the unprinted surface of the sheet of paper T. Consequently, duplex printing is performed on the sheet of paper T. 
     Thereafter the sheet of paper T that has been duplex printed is discharged from the first discharging portion  50   a  to the inner accumulation portion  510 . This completes the printing operation. 
     The following effects are obtained according to the first embodiment, for example. 
     The copying machine  1  according to the present embodiment includes the first discharging portion  50   a , the inner accumulation portion  510  and the pressing member  200 . The first discharging portion  50   a  discharges a sheet of paper T with an image formed by the image forming portion GK. The sheet of paper T discharged from the first discharging portion  50   a  is stacked in the inner accumulation portion  510 . The inner accumulation portion  510  includes a stacking surface portion  520  that has a planar portion  521  formed flat and a first protruding portion  523  formed to project upwardly from the planar portion. The pressing member  200  is disposed in contact with an upper surface of the sheet of paper T stacked on the stacking surface portion  520 . 
     Accordingly, it is possible to deform the sheet of paper T stacked on the stacking surface portion  520  along the first protruding portion  523  in the vertical direction. In this manner, it is possible to implement the configuration in which the sheet of paper T that extends in the discharging direction D 1  is stacked on the stacking surface portion  520  without increasing the length of the stacking surface portion  520  in the discharging direction D 1  and the height of the stacking space portion  540  in the perpendicular direction (vertical direction) Z. As a result, it is possible to inhibit an increase in the size of the device. Consequently, it is possible to realize downsizing and economizing of space in relation to the device. 
     The inner accumulation portion  510  in the copying machine  1  according to the present embodiment includes the restriction wall  550 . The restriction wall  550  is disposed to face the distal end of the sheet of paper T stacked on the stacking surface portion  520  in the discharging direction D 1 . The restriction wall  550  restricts the sheet of paper T stacked on the stacking surface portion  520  from moving in the discharging direction D 1 . The length from the end on the side closer to the first discharging portion  50   a  to the restriction wall  550  of the virtual surface (the flat surface without the first protruding portion  523 , the second protruding portion  524  and the third protruding portion  525  on the stacking surface portion  520 ) in the discharging direction D 1  is less than the length of the sheet of paper T in the discharging direction D 1 . The length along the surface of the stacking surface portion  520  including the first protruding portion  523  from the end on the side closer to the first discharging portion  50   a  to the restriction wall  550  in the discharging direction D 1  is equal to or greater than the length of the sheet of paper T in the discharging direction D 1 . 
     As a result, even when the length of the virtual surface on the stacking surface portion  520  in the discharging direction D 1  is shorter than the sheet of paper T of maximum size, this sheet of paper T can be stacked on the stacking surface portion  520  by deforming the sheet of paper T in the vertical direction by using the first protruding portion  523 . In this manner, it is possible to stack the sheet of paper T of maximum size on the stacking surface portion  520  while preventing an increase in the dimensions of the device. 
     Furthermore, the pressing member  200  in the copying machine  1  according to the present embodiment is disposed in contact with the upper surface of the sheet of paper T stacked on the stacking surface portion  520  in proximity to the first protruding portion  523 . The pressing member  200  is disposed in contact with the upper surface of the sheet of paper T stacked on the stacking surface portion  520 , while deforming the sheet of paper T along the first protruding portion  523 , compared with a state in which the pressing member  200  is not contact with the upper surface of the sheet of paper T stacked on the stacking surface portion  520 . In this manner, it is possible to cause the sheet of paper T stacked on the stacking surface portion  520  to be more deformed along the first protruding portion  523 . As a result, it is possible to further inhibit an increase in the size of the device. 
     The pressing member  200  is configured to be in contact with the upper surface of the sheet of paper T in proximity to the first protruding portion  523 . As a result, even when the sheet of paper T exhibits high rigidity, it is possible to cause the sheet of paper T to be deformed along the first protruding portion  523 . 
     The pressing member  200  in the copying machine  1  according to the present embodiment is disposed in contact with the upper surface of the sheet of paper T stacked on the stacking surface portion  520 , more downstream than the first protruding portion  523  in the discharging direction D 1 . As a result, the pressing member  200  pushes the sheet of paper T, which is conveyed diagonally upward by the first upward slope  523 A upstream of the first protruding portion  523 , to move along the first downward slope  523 B downstream of the first protruding portion  523 . In this manner, it is possible to cause the sheet of paper T stacked on the stacking surface portion  520  to be more deformed along the first protruding portion  523 . 
     In the copying machine  1  according to the present embodiment, the stacking surface portion  520  is disposed at a lower portion of the inner accumulation portion  510  in the vertical direction Z. The inner accumulation portion  510  further includes the stacking top surface portion  530  facing the stacking surface portion  520  in the vertical direction Z, and the stacking space portion  540  between the stacking surface portion  520  and the stacking top surface portion  530 . The base portion  201  of the pressing member  200  is rotatably attached to the stacking top surface portion  530 . The distal end portion  202  of the pressing member  200  is configured as a free end, and is disposed in contact with the upper surface of the sheet of paper T stacked on the stacking surface portion  520 . The pressing member  200  allows the sheet of paper T that moves to be stacked on the stacking surface portion  520  by rotating the distal end portion  202  to move in a direction opposite to the first discharging portion  50   a . Subsequently, the pressing member  200  comes in contact with the upper surface of the sheet of paper T that is allowed to move, and deforms the sheet of paper T. 
     The pressing member  200  rotating in this manner not only allows the sheet of paper T to move in the discharging direction D 1 , but also comes in contact with the upper surface of the sheet of paper T thus allowed to move. Accordingly, the pressing member  200  does not interfere with stacking of the sheet of paper T discharged from the first discharging portion  50   a  onto the stacking surface portion  520 . Furthermore, the pressing member  200  comes in contact with the upper surface of the sheet of paper T, thereby deforming the sheet of paper T along the first protruding portion  523 . 
     The copying machine  1  according to the present embodiment further includes the image reading unit  301  disposed at the upper portion of the case member BD. The stacking top surface portion  530  is configured by the lower portion of the image reading unit  301 . Consequently, the pressing member  200  can be attached to the lower portion of the image reading unit  301 . In this manner, it is possible to simply dispose the pressing member  200  in the stacking space portion  540 . Accordingly, it is possible that the distal end portion  202  of the pressing member  200  simply comes in contact with the upper surface of the sheet of paper T stacked on the stacking surface portion  520 . Therefore, it is possible to realize the simple configuration of disposing the pressing member  200 . 
     The stacking space portion  540  is a space that is limited in the vertical direction Z. For example, it may be possible that the entirety of the stacking surface portion  520  is composed of a flat surface having an inclination. However, if the length along the surface of the stacking surface portion  520  in the discharging direction D 1  is realized by the flat surface having an inclination, it will lead to an increase in the dimensions of the device in the vertical direction Z. In contrast, it is possible for the present disclosure to deform the sheet of paper T in the vertical direction by the first protruding portion  523 , even when the stacking space portion  540  is a space limited in the vertical direction Z. As a result, it is possible to inhibit an increase in the size of the device. 
     A second embodiment will be described with reference to the figures as another embodiment of an image forming apparatus  1  according to the present disclosure. Those components that are the same as the first embodiment will be denoted by the same reference numerals in the description of the second embodiment, and the corresponding description will be omitted or simplified. 
       FIG. 7  is a perspective view illustrating the configuration of a pressing member  200 A according to the second embodiment. In comparison to the first embodiment, the principal difference of the copying machine  1  according to the second embodiment is the configuration of a distal end portion  202 A of the pressing member  200 A. 
     As illustrated in  FIG. 7 , a portion of the distal end portion  202 A of the pressing member  200 A according to the second embodiment, which comes in contact with an upper surface of a sheet of paper T, includes a cylindrical roller  206  that acts as a rotating member. The roller  206  rotates about a rotation axis that extends in a paper width direction W and is provided at the distal end portion  202 A. In this manner, the roller  206  rotates in contact with the upper surface of the conveyed sheet of paper T. The roller member  206  at the distal end portion  202 A causes the distal end portion  202 A of the pressing member  200 A to be in contact with the upper surface of the sheet of paper T in a state of low frictional resistance. 
     In addition to the same effects as the first embodiment, the copying machine  1  according to the second embodiment obtains the following effects. 
     In the second embodiment, the portion of the distal end portion  202 A of the pressing member  200 A, which comes in contact with the upper surface of the sheet of paper T, includes the roller  206 . Accordingly, the roller  206  rotates in contact with the upper surface of the conveyed sheet of paper T. As a result, the frictional resistance between the distal end portion  202 A (roller  206 ) of the pressing member  200 A and the sheet of paper T is reduced. In this manner, when the sheet of paper T is stacked onto a stacking surface portion  520 , it is possible to inhibit a rear end of the sheet of paper T from remaining in a pair of discharging and reversing rollers  55 . When the sheet of paper T is conveyed in a return direction D 2  in contact with the distal end portion  202 A of the pressing member  200 A for reversing the sheet of paper T during duplex printing, it is possible to inhibit the sheet of paper T from catching on the pressing member  200 A. 
     A third embodiment will be described with reference to the figures as another embodiment of an image forming apparatus  1  according to the present disclosure. Those components that are the same as the first embodiment will be denoted by the same reference numerals in the description of the third embodiment and the corresponding description will be omitted or simplified. 
       FIG. 8  is a perspective view illustrating the configuration of a pressing member  200 B according to the third embodiment. In comparison to the first embodiment and the second embodiment, the principal difference of the copying machine  1  according to the third embodiment is the configuration of a distal end portion  202 B of the pressing member  200 B. 
     As illustrated in  FIG. 8 , a portion of the distal end portion  202 B of the pressing member  200 B according to the third embodiment, which comes in contact with an upper surface of a sheet of paper T, includes a sheet member  207  that exhibits a low frictional coefficient. In this manner, the distal end portion  202 B of the pressing member  200 B is in contact with the upper surface of the sheet of paper T in a low frictional resistance. 
     The copying machine  1  according to the third embodiment obtains the same effects as the second embodiment. 
     More specifically, the portion of the distal end portion  202 B of the pressing member  200 B, which comes in contact with the upper surface of the sheet of paper T, includes the sheet member  207 . Accordingly, it is possible to reduce the frictional resistance between the distal portion  202 B (sheet member  207 ) of the pressing member  200 B and the sheet of paper T, similarly with the second embodiment. In this manner similarly with the second embodiment, when the sheet of paper T is stacked onto the stacking surface portion  520 , it is possible to inhibit a rear end of the sheet of paper T from remaining in a pair of discharging and reversing rollers  55 . Furthermore, when the sheet of paper T is conveyed in a return direction D 2  in contact with the distal end portion  202 B of the pressing member  200 B for reversing the sheet of paper T during duplex printing, it is possible to inhibit the sheet of paper T from catching on the pressing member  200 B. 
     A fourth embodiment will be described with reference to the figures as another embodiment of an image forming apparatus  1  according to the present disclosure. Those components that are the same as the first embodiment and the second embodiment will be denoted by the same reference numerals in the description of the fourth embodiment, and the corresponding description will be omitted or simplified. 
       FIG. 9  is a side view illustrating the configuration of a pressing member  200 A and an inner accumulating portion  510 A according to the fourth embodiment.  FIG. 10  is a perspective view illustrating the configuration of a stacking surface portion  520 A on which sheets of paper T are stacked according to the fourth embodiment.  FIG. 11  is a perspective view illustrating the configuration of the stacking surface portion  520 A on which sheets of paper T are not stacked according to the fourth embodiment. 
     The copying machine  1  according to the fourth embodiment differs from the copying machine  1  according to the first embodiment mainly in that there is no protruding portion  522  and there is a recessed portion  527 . In the copying machine  1  according to the fourth embodiment, a portion of a distal end portion  202  that comes in contact with a sheet of paper T includes a roller  206  of the second embodiment. 
     As illustrated in  FIGS. 9 to 11 , a stacking surface portion  520 A according to the fourth embodiment includes a planar portion  521  and a plurality of recessed portions  527 . The planar portion  521  is formed flat. The plurality of recessed portions  527  is formed to be recessed downwardly in a vertical direction Z at the planar portion  521 . The plurality of recessed portions  527  is each formed in a shape of a valley having a bottom when viewed in a paper width direction W. 
     The plurality of recessed portions  527  includes one first recessed portion  528  and one second recessed portion  529 . The one first recessed portion  528  is formed at the recessed surface portion  520  upstream in the discharging direction D 1 . The one second recessed portion  529  is formed at the recessed surface portion  520  downstream in the discharging direction D 1 . 
     The first recessed portion  528  and the second recessed portion  529  have the same shape and only differ from each other in their positions with respect to the discharging direction D 1 . The first recessed portion  528  and the second recessed portion  529  are formed to extend across the whole area in the paper width direction W. 
     The first recessed portion  528  is formed to extend across the whole area in the paper width direction W more upstream than the center of the stacking surface portion  520 A in the discharging direction D 1 . The first recessed portion  528  includes a first upstream slope  528 A, a first bottom surface  528 B, and a first downstream slope  528 C that are sequentially formed from upstream to downstream in the discharging direction D 1 . 
     The first bottom surface  528 B is a horizontal bottom surface that is formed at the most recessed position of the first recessed portion  528 . The first upstream slope  528 A inclines downwardly from upstream to downstream of the discharging direction D 1 . The first downstream slope  528 C inclines upwardly from upstream to downstream of the discharging direction D 1 . 
     The second recessed portion  529  is formed at the downstream end of the stacking surface portion  520 A in the discharging direction D 1  across the whole area in the paper width direction W. The second recessed portion  529  includes a second upstream slope  529 A, a second bottom surface  529 B, and a second downstream slope  529 C that are sequentially formed from upstream to downstream in the discharging direction D 1 . 
     The second bottom surface  529 B is a horizontal bottom surface that is formed at the most recessed position of the second recessed portion  529 . The second upstream slope  529 A inclines downwardly from upstream to downstream of the discharging direction D 1 . The second downstream slope  529 C inclines upwardly from upstream to downstream in the discharging direction D 1 . 
     The roller  206  of the pressing member  200 A is disposed to face the first bottom surface  528 B of the first recessed portion  528 . The roller  206  is disposed in contact with an upper surface portion of a sheet of paper T corresponding to the first bottom surface  528 B, the sheet of paper T being stacked on the stacking surface portion  520 . 
     The copying machine  1  according to the fourth embodiment obtains the same effect as the first embodiment and the second embodiment. 
     More specifically, the roller  206  of the distal end portion  202 A of the pressing member  200 A comes in contact with the upper surface portion of the sheet of paper T corresponding to the first recessed portion  528 , the sheet of paper T being stacked on the stacking surface portion  520 . Consequently, the roller  206  can deform the sheet of paper T stacked on the stacking surface portion  520  along the recessed portion  528 . In this manner, it is possible that the pressing member  200 A deforms the sheet of paper T stacked on the stacking surface portion  520 A in a vertical direction Z. As a result, it is possible to inhibit an increase in the size of the device. 
     Although the preferred embodiments have been described above, the present disclosure is not limited to the embodiments described above and may be executed in various configurations. 
     For example, in the first embodiment described above, the stacking surface portion  520  includes the protruding portion  522 . In the fourth embodiment, the stacking surface portion  520 A includes the recessed portion  527 . However, the disclosure is not limited to such examples, and may include both the protruding portion  522  and the recessed portion  527  at the same time. 
     In the embodiments above, although the plurality of protruding portions  522  or the plurality of recessed portions  527  is described as an example, the disclosure is not limited to such an example. For example, it may be alternatively possible that there is only one protruding portion  522  or only one recessed portion  527 . 
     Furthermore, in the first embodiment above, the pressing member  200  is disposed in contact with the upper surface of the sheet of paper T more downstream than the first protruding portion  523  in the discharging direction D 1  as an example. However, the disclosure is not limited to such an example. It may be alternatively possible that the pressing member  200  is disposed in contact with the upper surface of the sheet of paper T more upstream than the first protruding portion  523  in the discharging direction D 1  or at a portion corresponding to the first protruding portion  523 . 
     In the embodiments above, although the pressing member  200  is formed flat as an example, the disclosure is not limited to such an example. It may be alternatively possible that the pressing member  200  is formed in a curved shape. 
     In the embodiments above, although the planar portion  521  of the stacking surface portion  520  is formed horizontal as an example, the disclosure is not limited to such an example. It may be alternatively possible that the planner portion  521  is formed diagonal. 
     The type of image forming apparatus according to the present disclosure is not limited and may include a copying machine, a printer, a facsimile, or a multifunction peripheral combining such devices. 
     Furthermore, the sheet medium is not limited to paper, and for example, may include a film sheet.