Patent Publication Number: US-11377320-B2

Title: Relay conveyance device, image forming system, combination of image forming system, and sheet conveyance device

Description:
INCORPORATION BY REFERENCE 
     The present application claims priority from Japanese Patent Application No. 2019-087426 filed on May 7, 2019, disclosure of which is all incorporated herein. 
     BACKGROUND 
     Field of the Invention 
     The present invention relates to a relay conveyance device which relays conveyance of a sheet from an image forming device to a post-processing device, an image forming system including the relay conveyance device, a combination of an image forming system, and sheet conveyance device. 
     Related Art 
     There is a known image forming system including an image forming device which forms an image on a sheet, a post-processing device which conducts predetermined post-processing for a sheet on which an image has been formed, and a relay conveyance device which is arranged between the image forming device and the post-processing device to relay conveyance of a sheet between both the devices. Examples of the post-processing device include a finisher which applies perforation processing to a sheet, staple processing, and the like, and a stacker which stacks and houses a large number of sheets. The relay conveyance device includes a discharge unit which discharges a sheet fed out from the image forming device toward the post-processing device. 
     Some kinds of post-processing devices have, at different height positions, carry-in ports into which sheets are carried. For example, a finisher has a carry-in port formed at a position higher than that of a carry-in port of a stacker. As a method of conveyancing a sheet to a carry-in port at a different height position, a post-processing device including a height adjustment base is known. 
     SUMMARY 
     A relay conveyance device according to one aspect of the present invention is a device arranged between an image forming device which forms an image on a sheet and one post-processing device applying predetermined post-processing to a sheet to relay conveyance of a sheet from the image forming device to the post-processing device, the post-processing device having a carry-in port which allows carry-in of a sheet. The relay conveyance device includes a device main body in which a relay conveyance path is provided as a conveyance path of a sheet fed out from the image forming device; a plurality of unit supporting portions provided, at a downstream end of the device main body in a sheet conveying direction, at positions different from each other in the height direction; a discharge unit supported by any one of the plurality of unit supporting portions to receive a sheet having passed through the relay conveyance path and discharge the sheet toward the carry-in port; a processing unit attached to the discharge unit to apply predetermined processing to the sheet; a processing unit adjustment portion capable of adjusting a height direction inclination of the processing unit relative to a sheet width direction orthogonal to both the height direction and the sheet conveying direction such that the processing unit maintains a horizontal reference position in a state where the processing unit is attached to the discharge unit; and a discharge unit adjustment mechanism capable of adjusting an inclination in the height direction of the discharge unit relative to the sheet width direction such that the processing unit adjusts the reference position in a state where in each of the plurality of unit supporting portions, the processing unit is supported by the discharge unit. 
     An image forming system according to another aspect of the present invention includes an image forming device which forms an image on a sheet; a post-processing device having a carry-in port which allows carry-in of a sheet and applying predetermined post-processing to a sheet; and the relay conveyance device arranged between the image forming device and the post-processing device to relay conveyance of a sheet from the image forming device to the post-processing device. 
     A combination of an image forming system according to a further aspect of the present invention includes an image forming device which forms an image on a sheet; a plurality of kinds of post-processing devices each capable of applying predetermined post-processing to a sheet and each having a carry-in port which allows carry-in of a sheet and which has a position in a height direction different from each other; and the relay conveyance device according to claim  1  arranged between the image forming device and one post-processing device selected from the plurality of kinds of post-processing devices to relay conveyance of a sheet from the image forming device to the one post-processing device. 
     A sheet conveyance device according to a further aspect of the present invention is a device arranged on an upstream side of a post-processing device which applies predetermined post-processing to the sheet, to convey the sheet to the post-processing device, the post-processing device having a carry-in port which allows carry-in of a sheet, the sheet conveyance device includes a device main body in which a conveyance path is provided; a plurality of unit supporting portions provided, at a downstream end of the device main body in a sheet conveying direction, at positions different from each other in the height direction; a discharge unit supported by any one of the plurality of unit supporting portions to receive a sheet having passed through the conveyance path and discharge the sheet toward the carry-in port; a processing unit attached to the discharge unit to apply predetermined processing to the sheet; a processing unit adjustment portion capable of adjusting a height direction inclination of the processing unit relative to a sheet width direction orthogonal to both the height direction and the sheet conveying direction such that the processing unit takes a horizontal reference position in a state where the processing unit is attached to the discharge unit; and a discharge unit adjustment mechanism capable of adjusting an inclination in the height direction of the discharge unit relative to the sheet width direction such that the processing unit adjusts the reference position in a state where in each of the plurality of unit supporting portions, the processing unit is supported by the discharge unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view showing an internal structure of an image forming system to which a relay conveyance device according to one embodiment of the present invention is applied, which shows a state where a finisher is coupled as a post-processing device; 
         FIG. 2  is a view showing an internal structure of the image forming system, which shows a state where a stacker is coupled as the post-processing device; 
         FIG. 3  is a perspective view showing a configuration of a sheet discharge portion in the relay conveyance device, the view showing a state where a discharge unit is supported by a first unit supporting portion; 
         FIG. 4  is a perspective view showing a configuration of the sheet discharge portion in the relay conveyance device, the view showing a state where the discharge unit is supported by a second unit supporting portion; 
         FIG. 5  is a perspective view showing a supported state of the discharge unit in the second unit supporting portion; 
         FIG. 6  is a perspective view of the discharge unit; 
         FIG. 7  is a perspective view showing a state where a decurling unit is removed from the discharge unit; 
         FIG. 8  is a perspective view showing the discharge unit viewed from an upstream side in a sheet conveying direction; 
         FIG. 9  is a perspective view showing, in an enlarged manner, a first processing position adjustment portion provided in an attachment portion of the discharge unit; 
         FIGS. 10A to 10C  are perspective views of a decurling unit to be attached to the discharge unit; 
         FIG. 11  is a view schematically showing an internal structure of the decurling unit; 
         FIG. 12  is an exploded perspective view of a second processing position adjustment portion provided in the decurling unit; 
         FIG. 13  is an exploded perspective view of the second processing position adjustment portion; 
         FIGS. 14A to 14C  are views showing a discharge adjustment mechanism; and 
         FIGS. 15A to 15C  are views showing how an inclination of the discharge unit is adjusted using the discharge adjustment mechanism. 
     
    
    
     DETAILED DESCRIPTION 
     In the following, a relay conveyance device (sheet conveyance device), an image forming system, and a combination of an image forming system according to an embodiment of the present invention will be described based on the drawings. 
       FIG. 1  and  FIG. 2  are views showing an internal structure of an image forming system  1  to which a relay conveyance device  3  is applied according to one embodiment of the present invention. The image forming system  1  includes an image forming device  2 , the relay conveyance device  3 , and a post-processing device  9 . The image forming system  1  is a system in which in the image forming device  2 , an image is formed on a sheet S, in the relay conveyance device  3 , the sheet S on which the image has been formed is conveyed to the post-processing device  9 , and in the post-processing device  9 , the sheet S is subjected to predetermined post-processing. In the following description, a direction on a horizontal surface of the sheet S, the direction representing a conveying direction of the sheet S, will be referred to as a “sheet conveying direction D 1 ”, and a direction orthogonal to the sheet conveying direction D 1 , the direction representing a width of the sheet S, will be referred to as a “sheet width direction D 2 ”. Additionally, a direction orthogonal to both the sheet conveying direction D 1  and the sheet width direction D 2  and vertically extending and representing a height of each device configuring the image forming system  1  will be referred to as a “height direction D 3 ”. 
     The image forming device  2  is a device which forms an image on the sheet S. Although an image forming method of the image forming device  2  is not particularly limited, an ink jet method is adopted in the example shown in  FIG. 1  and  FIG. 2 . The image forming device  2  includes a device main body  21 , a sheet feeding portion  22 , a sheet conveyance portion  23 , an image forming portion  24 , and a sheet ejecting portion  25 . 
     The device main body  21  is a box-shaped casing which houses each kind of device for forming an image on the sheet S. In the device main body  21 , a first conveyance path GP 1  and a second conveyance path GP 2  are formed as conveyance paths of the sheet S. The first conveyance path GP 1  is a conveyance path passing from the sheet feeding portion  22  to the sheet ejecting portion  25  through the image forming portion  24 . The second conveyance path GP 2 , which is a conveyance path that reverses the back and front of the sheet S, branches from the first conveyance path GP 1  on a downstream side of the image forming portion  24  in the conveying direction D 1  of the sheet S and joins with the first conveyance path GP 1  on an upstream side of the image forming portion  24 . 
     The sheet feeding portion  22  feeds the sheet S to the first conveyance path GP 1 . The sheet feeding portion  22  includes a sheet feeding cassette  221  and a pickup roller  222 . The sheet feeding cassette  221  is detachable from the device main body  21  and internally houses the sheet S. The pickup roller  222  draws out an uppermost sheet S of a bundle of the sheets housed in the sheet feeding cassette  221  one by one and sends out the sheet to the first conveyance path GP 1 . 
     The sheet S fed to the first conveyance path GP 1  is conveyed to a resist roller pair  233  of the sheet conveyance portion  23  by a conveyance roller pair TR provided in the first conveyance path GP 1 . The resist roller pair  233  conducts skew correction of the sheet S and also sends out the sheet S toward a conveyance belt  231  at timing of image forming processing by the image forming portion  24 . Upon having a front end portion come into contact with an outer circumferential surface of the conveyance belt  231 , the sheet S sent out by the resist roller pair  233  is conveyed in the sheet conveying direction D 1  while being held on the outer circumferential surface by driving by the conveyance belt  231 . 
     The sheet conveyance portion  23  is arranged below the image forming portion  24  in the height direction D 3  so as to be opposed to the image forming portion  24 . The sheet conveyance portion  23  includes the conveyance belt  231  and a suction portion  232 . The conveyance belt  231  holds, on the outer circumferential surface thereof, the sheet S sent out by the resist roller pair  233  and circulates while holding the sheet S to conveyance the sheet in the sheet conveying direction D 1 . The conveyance belt  231  has a plurality of suction holes extending from the outer circumferential surface to an inner circumferential surface of the belt in a thickness direction. The suction portion  232  is arranged so as to be opposed to the inner circumferential surface of the conveyance belt  231 . The suction portion  232  brings the sheet S into close contact with the outer circumferential surface of the conveyance belt  231  by generating a negative pressure between the sheet S held on the outer circumferential surface of the conveyance belt  231  and the conveyance belt  231 . The suction portion  232  generates suction force by sucking air from a space above the conveyance belt  231  through the suction holes of the conveyance belt  231 . The suction force generates, in a space above the conveyance belt  231 , an air flow (suction air) directed to the suction portion  232 . When the sheet S covers a part of the outer circumferential surface of the conveyance belt  231 , suction force (negative pressure) acts on the sheet S to bring the sheet S into close contact with the outer circumferential surface of the conveyance belt  231 . 
     The image forming portion  24  is arranged above the sheet conveyance portion  23  so as to be opposed to the outer circumferential surface of the conveyance belt  231 . The image forming portion  24  forms an image by applying the image forming processing to the sheet S, the sheet S being conveyed in the sheet conveying direction D 1  while being held on the outer circumferential surface of the conveyance belt  231 . In the present embodiment, the image forming portion  24 , using an ink jet method as an image forming method, forms an image on the sheet S by jetting an ink. The image forming portion  24  is configured with a recording head which jets an ink. In the examples shown in  FIG. 1  and  FIG. 2 , the image forming portion  24  is configured with four recording heads which jet color inks of yellow, magenta, cyan, and black, respectively. 
     The sheet S on which an image has been formed by the image forming portion  24  is discharged toward the relay conveyance device  3  through a sheet ejecting port  251  by the sheet ejecting portion  25  provided at a downstream end of the first conveyance path GP 1 . On the other hand, in a case where the sheet S having passed through the image forming portion  24  is for double-sided printing and has a first face (a front face) thereof finished with the image forming processing, the sheet S is sent out to the second conveyance path GP 2  to have its back and front reversed. The sheet S having been conveyed through the second conveyance path GP 2  is again supplied onto the outer circumferential surface of the conveyance belt  231  while having its back and front reversed via the resist roller pair  233 . The sheet S supplied to the conveyance belt  231  with its back and front reversed in this manner has its second face (a back face), which is reverse to the first face, subjected to the image forming processing by the image forming portion  24  while being conveyed by the conveyance belt  231 . The sheet S finished with the double-sided printing is discharged by the sheet ejecting portion  25  toward the relay conveyance device  3  through the sheet ejecting port  251 . 
     The relay conveyance device  3  (sheet conveyance device) is arranged between the image forming device  2  and the post-processing device  9  in the sheet conveying direction D 1 . In other words, the relay conveyance device  3  is arranged on a downstream side of the image forming device  2  and an upstream side of the post-processing device  9  in the sheet conveying direction D 1 . The relay conveyance device  3  is a device which relays conveyance of the sheet S from the image forming device  2  to the post-processing device  9 . The relay conveyance device  3  receives, from a receiving port  311 , the sheet S discharged from the sheet ejecting port  251  of the image forming device  2  and discharges the sheet S toward the post-processing device  9 . Details of the relay conveyance device  3  will be described later. 
     The post-processing device  9  is a device which subjects the sheet S on which an image has been formed to predetermined post-processing, the sheet S being discharged from the relay conveyance device  3 . As the post-processing device  9 , there are provided a plurality of kinds of devices each having a carry-in port CIP into which the sheet S is carried, each carry-in port CIP being different from each other in position in the height direction D 3 . In the image forming system  1 , one post-processing device selected from the plurality of kinds of the post-processing devices  9  is coupled to a downstream side of the relay conveyance device  3 . In  FIG. 1 , a finisher  9 A is illustrated as the post-processing device  9  coupled to the relay conveyance device  3 . The finisher  9 A is a post-processing device which selectively applies perforation processing to the sheet S, staple processing, and saddle folding processing. In  FIG. 2 , a stacker  9 B is illustrated as the post-processing device  9  coupled to the relay conveyance device  3 . The stacker  9 B is a post-processing device which houses a large number of sheets S. A system including the image forming device  2 , the finisher  9 A, the stacker  9 B, and the relay conveyance device  3  configures a combination of an image forming system according to the present invention. The relay conveyance device  3  is arranged between the post-processing device, which is either the finisher  9 A or the stacker  9 B, and the image forming device  2 . 
     The finisher  9 A (the post-processing device  9 ) shown in  FIG. 1  includes a device main body  91 , a perforation device  92  housed in the device main body  91 , a staple device  93 , and a saddle folding device  94 . In the device main body  91 , the perforation device  92  is arranged in an upper portion, the staple device  93  is arranged in a middle portion, and the saddle folding device  94  is arranged in a lower portion in the height direction D 3 . 
     In a side surface of the device main body  91  at an upstream side in the sheet conveying direction D 1 , the side surface being opposed to the relay conveyance device  3 , there is formed the carry-in port CIP into which the sheet S discharged from the relay conveyance device  3  is carried. Also in a side surface of the device main body  91  opposite to the relay conveyance device  3 , a first discharge port  911  is formed at the side of the perforation device  92 , a second discharge port  912  is formed at the side of the staple device  93 , and a third discharge port  913  is formed at the side of the saddle folding device  94 . 
     In the device main body  91 , a first conveyance path FP 1 , a second conveyance path FP 2 , and a third conveyance path FP 3  are formed. The first conveyance path FP 1  is a conveyance path directed from the carry-in port CIP toward the first discharge port  911  through the perforation device  92 . The second conveyance path FP 2  is a conveyance path which branches, on a downstream side of the perforation device  92 , from the first conveyance path FP 1  and passes through the staple device  93  toward the second discharge port  912 . The third conveyance path FP 3  is a conveyance path which branches from the second conveyance path FP 2  and passes through the saddle folding device  94  toward the third discharge port  913 . 
     The sheet S discharged from the relay conveyance device  3  is carried from the carry-in port CIP into the device main body  91  and introduced into the first conveyance path FP 1 . It is assumed that in the finisher  9 A, the sheet S is subjected to the perforation processing. In this case, the sheet S is conveyed to the perforation device  92  through the first conveyance path FP 1 . The perforation device  92  applies the perforation processing to the sheet S. The sheet S after being subjected to the perforation processing passes through the first conveyance path FP 1  so as to be discharged from the first discharge port  911  and stacked in a first discharge tray  95 . It is assumed that in the finisher  9 A, the staple processing is conducted. In this case, the sheet S is conveyed from the first conveyance path FP 1  to the staple device  93  along the second conveyance path FP 2 . The staple device  93  applies the staple processing to the sheet S. The sheet S after being subjected to the staple processing passes through the second conveyance path FP 2  so as to be discharged from the second discharge port  912  and stacked in a second discharge tray  96 . It is assumed that in the finisher  9 A, the saddle folding processing is conducted. In this case, the sheet S is conveyed from the first conveyance path FP 1  to the saddle folding device  94  along the second conveyance path FP 2  and the third conveyance path FP 3 . The saddle folding device  94  conducts the saddle folding processing of saddle-stitching and saddle-folding the sheet S. The sheet S having been subjected to the saddle folding processing passes through the third conveyance path FP 3  and is discharged from the third discharge port  913  and stacked in a third discharge tray  97 . 
     The stacker  9 B (the post-processing device  9 ) shown in  FIG. 2  includes a device main body  98  and a large capacity tray  99  housed in the device main body  98 . In a side surface of the device main body  98  at an upstream side in the sheet conveying direction D 1 , the side surface being opposed to the relay conveyance device  3 , there is formed the carry-in port CIP into which the sheet S discharged from the relay conveyance device  3  is carried. The large capacity tray  99  accumulates and houses the sheets S carried into the device main body  98  from the carry-in port CIP. In general, a position (height position) of the carry-in port CIP of the stacker  9 B in the height direction D 3  is lower than a height position of the carry-in port CIP of the finisher  9 A. 
     Next, the relay conveyance device  3  will be detailed. The relay conveyance device  3  is provided separately from the image forming device  2  and the post-processing device  9  and is coupled to each of the image forming device  2  and the post-processing device  9 . The relay conveyance device  3  is capable of selectively conducting the back and front inversion of the sheet S and the position correction of the sheet S in the sheet width direction D 2  while relaying conveyance of the sheet S from the image forming device  2  to the post-processing device  9 . 
     The relay conveyance device  3  includes a device main body  31 , a relay conveyance path  32  provided within the device main body  31 , and a sheet discharge portion  33 . 
     In a side surface of the device main body  31  at an upstream side in the sheet conveying direction D 1 , the side surface being opposed to the image forming device  2 , there is formed the receiving port  311  which receives the sheet S discharged from the sheet ejecting port  251  of the image forming device  2 . A position (height position) of the receiving port  311  in the height direction D 3  is same as a height position of the sheet ejecting port  251 . “A height position is same” represents a state where a difference in height position between the receiving port  311  and the sheet ejecting port  251  is within a predetermined allowable range. 
     The sheet S received through the receiving port  311  into the device main body  31  is introduced to the relay conveyance path  32  (conveyance path). The relay conveyance path  32  is a conveyance path directed from the receiving port  311  to the sheet discharge portion  33 . At each portion of the relay conveyance path  32 , the conveyance roller pair TR which conveyances the sheet S is provided. The relay conveyance path  32  has, from its upstream side in the sheet conveying direction D 1 , a first common path M 1 , a first inversion path I 1  and a second inversion path I 2 , a second common path M 2 , a first correction path C 1  and a second correction path C 2 , a third common path M 3 , and a fourth common path M 4  in this order. The first inversion path I 1  and the second inversion path I 2  are inversion portions which reverse the back and front of the sheet S. The first correction path C 1  and the second correction path C 2  are correction portions which correct a position of the sheet S in the sheet width direction D 2 . 
     The first common path M 1  extends substantially horizontally from the receiving port  311  and branches at a first branch point B 1  into the first inversion path I 1  and the second inversion path I 2 . 
     The first inversion path I 1  has a switch back path I 11  in which a sheet conveying direction is inverted, a forward path I 12  in which the sheet S is conveyed to the switch back path I 11 , and a backward path I 13  in which the switched back sheet S is conveyed. The forward path I 12  extends substantially horizontally from the first branch point B 1  to a downstream side in the sheet conveying direction D 1 . The switch back path I 11  slants to extend downward from an exit of the forward path I 12 . The backward path I 13  extends downward from an entrance of the switch back path I 11 . 
     The second inversion path I 2  has a switch back path I 21  in which the conveying direction of the sheet S is inverted, a forward path I 22  in which the sheet S is conveyed to the switch back path I 21 , and a backward path I 23  in which a switched back sheet S is conveyed. The forward path I 22  extends downward from the first branch point B 1 . The switch back path I 21  extends downward from an exit of the forward path I 22 . The backward path I 23  extends from an entrance of the switch back path I 21  to the downstream side of the sheet conveying direction D 1 . 
     The backward path I 13  of the first inversion path I 1  and the backward path I 23  of the second inversion path I 2  join at a first joining point J 1 . After extending downward from the first joining point J 1 , the second common path M 2  is folded back upward while curving. The second common path M 2  branches at a second branch point B 2  into the first correction path C 1  and the second correction path C 2 . 
     The first correction path C 1  and the second correction path C 2  are formed vertically in line and extend in a substantially horizontal direction. The first correction path C 1  and the second correction path C 2  are each provided with three pairs of switching rollers CR 1  and a correction roller pair CR 2  sequentially from the upstream side. An upper roller of each switching roller pair CR 1  is movable in the height direction D 3  between a nip position at which the upper roller sandwiches the sheet S with a lower roller and a nip releasing position upwardly spaced apart from the sheet S. The correction roller pair CR 2  is movable in the sheet width direction D 2 . 
     The first correction path C 1  and the second correction path C 2  join at a second joining point J 2 . The third common path M 3  extends upward from the second joining point J 2 . An exit of the third common path M 3  is connected to a discharge unit  5  when the discharge unit  5  is supported by a second unit supporting portion  45  in the sheet discharge portion  33  to be described later (see  FIG. 2 ). The fourth common path M 4  extends further upwardly from the third common path M 3 . An exit of the fourth common path M 4  is connected to the discharge unit  5  when the discharge unit  5  is supported by a first unit supporting portion  44  in the sheet discharge portion  33  to be described later (see  FIG. 1 ). 
     The relay conveyance path  32  further has a first sub-path S 1  and a second sub-path S 2 . The first sub-path S 1  is a conveyance path in which the sheet S not requiring inversion and position correction, and the post-processing is conveyed. The second sub-path S 2  is a conveyance path in which the sheet S not requiring inversion and position correction, and requiring only the post-processing is conveyed. The first sub-path S 1  branches upward at a third branch point B 3  in the middle of the forward path I 12  of the first inversion path I 1  to extend toward a discharge tray  312 . The second sub-path S 2  branches at a fourth branch point B 4  in the middle of the switch back path I 11  of the first inversion path I 1  to extend toward the sheet discharge portion  33 . The second sub-path S 2  branches at a fifth branch point B 5  into an upper path S 21  and a lower path S 22 . The upper path S 21  extends toward the first unit supporting portion  44  in the sheet discharge portion  33 . The lower path S 22  extends toward the second unit supporting portion  45  in the sheet discharge portion  33 . 
     The sheet S discharged from the image forming device  2  and having passed through the relay conveyance path  32  is introduced to the sheet discharge portion  33 . The sheet discharge portion  33  is arranged at a downstream end of the device main body  31  in the sheet conveying direction D 1 . The sheet discharge portion  33  will be described with reference to  FIG. 3  to  FIG. 5  in addition to  FIG. 1  and  FIG. 2 .  FIG. 3  and  FIG. 4  are perspective views showing a configuration of the sheet discharge portion  33  in the relay conveyance device  3 .  FIG. 5  is a perspective view showing a supported state of the discharge unit  5  in the second unit supporting portion  45  of the sheet discharge portion  33 . 
     The sheet discharge portion  33  is configured to include a discharge portion main body  4 , the discharge unit  5 , a decurling unit  57  (a processing unit), and a discharge adjustment mechanism  8 . 
     The discharge portion main body  4  forms a portion of the downstream end of the device main body  31  in the sheet conveying direction D 1 . The discharge portion main body  4  is a structure for defining the first unit supporting portion  44  and the second unit supporting portion  45  provided corresponding to positions (height positions) of the respective carry-in ports CIP for the plurality of kinds of post-processing devices  9  in the height direction D 3 . The discharge portion main body  4  has a first frame body  41  and a second frame body  42 . 
     The first frame body  41  is formed to have a rectangular frame shape with an opening at the center thereof and defines a downstream side end portion of the discharge portion main body  4  in the sheet conveying direction D 1 . The first frame body  41  has a first side pillar  411  and a second side pillar  412  which are arranged to be opposed to and spaced apart from each other by a predetermined interval in the sheet width direction D 2  and which extend in the height direction D 3 . The first side pillar  411  is zoned into a first side pillar upper portion  4111  on an upper side and a first side pillar lower portion  4112  on a lower side in the height direction D 3 . To the second side pillar  412 , a side surface board  43  extending to the second frame body  42  is attached. To a downstream end portion of the side surface board  43  in the sheet conveying direction D 1 , a first supporting member  431  is fixed at a position, in the height direction D 3 , corresponding to the first side pillar upper portion  4111  and a second supporting member  432  is fixed at a position, in the height direction D 3 , corresponding to the first side pillar lower portion  4112 . 
     The second frame body  42  is formed to have a rectangular frame shape with an opening at the center thereof and defines an upstream side end portion of the discharge portion main body  4  in the sheet conveying direction D 1 . The second frame body  42  is zoned into an upper side second frame body upper portion  421  and a lower side second frame body lower portion  422  in the height direction D 3 . 
     The first unit supporting portion  44  is configured to include the first side pillar upper portion  4111  and the first supporting member  431 , and the second frame body upper portion  421 . In the first unit supporting portion  44 , a downstream end portion in the sheet conveying direction D 1  is configured with the first side pillar upper portion  4111  and the first supporting member  431 , and an upstream end portion in the sheet conveying direction D 1  is configured with the second frame body upper portion  421 . The first unit supporting portion  44 , which is a reference unit supporting portion, is provided corresponding to a position of the carry-in port CIP of the finisher  9 A as the post-processing device  9  in the height direction D 3  (see  FIG. 1 ). In a case where the finisher  9 A is coupled to the relay conveyance device  3 , the discharge unit  5  is supported in the first unit supporting portion  44  ( FIG. 3 ). 
     The second unit supporting portion  45  is configured to include the first side pillar lower portion  4112  and the second supporting member  432 , and the second frame body lower portion  422 . In the second unit supporting portion  45 , a downstream end portion in the sheet conveying direction D 1  is configured with the first side pillar lower portion  4112  and the second supporting member  432 , and an upstream end portion in the sheet conveying direction D 1  is configured with the second frame body lower portion  422 . The second unit supporting portion  45  is provided corresponding to a position of the carry-in port CIP of the stacker  9 B as the post-processing device  9  in the height direction D 3  and is different from the first unit supporting portion  44  in the position in the height direction D 3  (see  FIG. 2 ). In a case where the stacker  9 B is coupled to the relay conveyance device  3 , the discharge unit  5  is supported in the second unit supporting portion  45  ( FIG. 4 ). 
     In the sheet discharge portion  33 , the number of the first unit supporting portions  44  and the number of the second unit supporting portions  45  are set according to the number of the post-processing devices  9  assumed to be coupled to the relay conveyance device  3 . While one first unit supporting portion  44  is provided as the reference, at least one second unit supporting portion  45  is provided which has a position in the height direction D 3  different from that of the first unit supporting portion  44 . In a case, for example, where two post-processing devices  9  having the carry-in ports CIP different in a height position are assumed to be coupled, one first unit supporting portion  44  is provided, while one second unit supporting portion  45  is provided. In a case where three post-processing devices  9  having the carry-in ports CIP different in a height position are assumed to be coupled, one first unit supporting portion  44  is provided, while two second unit supporting portions  45  are provided. 
     The discharge unit  5  is supported by either the first unit supporting portion  44  or the second unit supporting portion  45  corresponding to the position in the height direction D 3  of the carry-in port CIP of the post-processing device  9  coupled to the relay conveyance device  3 . The discharge unit  5  receives the sheet S having passed through the relay conveyance path  32  ( FIG. 1  and  FIG. 2 ) and also discharges the sheet S toward the carry-in port CIP of the post-processing device  9 . Additionally, as shown in  FIG. 3  and  FIG. 4 , to the discharge unit  5 , the decurling unit  57  is detachably attached. The decurling unit  57  is one example of a processing unit which subjects the sheet S received by the discharge unit  5  to predetermined processing. The decurling unit  57  is a unit which decurls the sheet S on which an image has been formed and which has passed through the relay conveyance path  32 . 
       FIG. 6  is a perspective view of the discharge unit  5 , and  FIG. 7  and  FIG. 8  are perspective views showing a state where the decurling unit  57  is removed from the discharge unit  5 . The discharge unit  5  includes a first frame  51 , a second frame  52 , an attachment portion  54 , a receiving portion  55 , and a unit discharge portion  56 . 
     The first frame  51  and the second frame  52  are frames which are arranged to be opposed to each other at a predetermined interval in the sheet width direction D 2  and extend along the sheet conveying direction D 1 . The first frame  51  and the second frame  52  are connected to each other by a plurality of connecting members  53  extending in the sheet width direction D 2  so as to adjust their positions in parallel to each other. In a state where the discharge unit  5  is supported by either the first unit supporting portion  44  or the second unit supporting portion  45 , the first frame  51  is arranged on a side where the first side pillar  411  in the first frame body  41  is provided to stand and the second frame  52  is arranged on a side where the second side pillar  412  in the first frame body  41  is provided to stand. 
     The first frame  51  has a first supported portion  511  and a second supported portion  512  spaced apart from each other in the sheet conveying direction D 1 . In the present embodiment, in the first frame  51 , the first supported portion  511  is arranged at a downstream end in the sheet conveying direction D 1  and the second supported portion  512  is arranged at an upstream end in the sheet conveying direction D 1 . The first frame  51  is supported by either the first unit supporting portion  44  or the second unit supporting portion  45  in the first supported portion  511  and the second supported portion  512 . In the first frame  51 , the first supported portion  511  is provided with a first insertion hole  511 H ( FIG. 7 ) and the second supported portion  512  is provided with a second insertion hole  512 H ( FIG. 8 ). 
     It is assumed that the discharge unit  5  is supported by the first unit supporting portion  44 . In this case, in the first frame  51 , the first supported portion  511  is supported by the first side pillar upper portion  4111  in the first side pillar  411  of the first frame body  41 , and the second supported portion  512  is supported by the second frame body upper portion  421  in the second frame body  42 . Supporting protrusions are provided at the first side pillar upper portion  4111  and a part of the second frame body upper portion  421  corresponding to the first side pillar upper portion  4111 , respectively. The first frame  51  is supported in the first unit supporting portion  44  with the supporting protrusion of the first side pillar upper portion  4111  being inserted in the first insertion hole  511 H of the first supported portion  511  and the supporting protrusion of the second frame body upper portion  421  being inserted in the second insertion hole  512 H of the second supported portion  512 . 
     By contrast, it is assumed that the discharge unit  5  is supported by the second unit supporting portion  45 . In this case, in the first frame  51 , the first supported portion  511  is supported by the first side pillar lower portion  4112  in the first side pillar  411  of the first frame body  41 , and the second supported portion  512  is supported by the second frame body lower portion  422  in the second frame body  42 . In the first side pillar lower portion  4112 , a supporting pin  81  of the discharge adjustment mechanism  8  to be described later is provided to protrude ( FIG. 5 ). A supporting protrusion is provided in a part of the second frame body lower portion  422  corresponding to the first side pillar lower portion  4112 . The first frame  51  is supported by the second unit supporting portion  45  in a state where the supporting pin  81  of the discharge adjustment mechanism  8  is inserted in the first insertion hole  511 H of the first supported portion  511  and the supporting protrusion of the second frame body lower portion  422  is inserted in the second insertion hole  512 H of the second supported portion  512 . 
     The second frame  52  has a third supported portion  521  and a fourth supported portion  522  spaced apart from each other in the sheet conveying direction D 1 . In the present embodiment, in the second frame  52 , the third supported portion  521  is arranged at a downstream end in the sheet conveying direction D 1  and the fourth supported portion  522  is arranged closer to a downstream side, within a predetermined range, than to an upstream end in the sheet conveying direction D 1 . The second frame  52  is supported by either the first unit supporting portion  44  or the second unit supporting portion  45  in the third supported portion  521  and the fourth supported portion  522 . In the second frame  52 , the third supported portion  521  is provided with a third insertion hole  521 H ( FIG. 7 ) and the fourth supported portion  522  is provided with a fourth insertion hole  522 H ( FIG. 8 ). 
     It is assumed that the discharge unit  5  is supported in the first unit supporting portion  44 . In this case, in the second frame  52 , the third supported portion  521  is supported by the first supporting member  431  fixed to the side surface board  43  and the fourth supported portion  522  is supported by the second frame body upper portion  421  in the second frame body  42 . The first supporting member  431  and a part of the second frame body upper portion  421  corresponding to the first supporting member  431  are provided with supporting protrusions, respectively. The second frame  52  is supported by the first unit supporting portion  44  in a state where the supporting protrusion of the first supporting member  431  is inserted in the third insertion hole  521 H of the third supported portion  521  and the supporting protrusion of the second frame body upper portion  421  is inserted in the fourth insertion hole  522 H of the fourth supported portion  522 . 
     By contrast, it is assumed that the discharge unit  5  is supported by the second unit supporting portion  45 . In this case, in the second frame  52 , the third supported portion  521  is supported by the second supporting member  432  fixed to the side surface board  43 , and the fourth supported portion  522  is supported by the second frame body lower portion  422  in the second frame body  42 . The second supporting member  432  and a part of the second frame body lower portion  422  corresponding to the second supporting member  432  are provided with the supporting protrusions SP, respectively. The second frame  52  is supported by the second unit supporting portion  45  in a state where the supporting protrusion SP of the second supporting member  432  is inserted in the third insertion hole  521 H of the third supported portion  521  and the supporting protrusion of the second frame body lower portion  422  is inserted in the fourth insertion hole  522 H of the fourth supported portion  522 . 
     As shown in  FIG. 7 , the attachment portion  54  is a part which is provided between the first frame  51  and the second frame  52  and to which the decurling unit  57  is attached in the discharge unit  5 . In other words, the attachment portion  54  is defined by the first frame  51 , the second frame  52 , and the plurality of connecting members  53 . 
     The receiving portion  55  is arranged, between the first frame  51  and the second frame  52 , on an upstream side of the attachment portion  54  in the sheet conveying direction D 1 . The receiving portion  55 , which is configured with, for example, a conveyance roller pair extending in the sheet width direction D 2 , rotates around a roller shaft to receive the sheet S having passed through the relay conveyance path  32 . The sheet S received by the receiving portion  55  is introduced to the decurling unit  57  attached to the attachment portion  54 . While subjecting the sheet S introduced by the receiving portion  55  to the decurling processing, the decurling unit  57  sends out the sheet S after the processing toward the downstream side. 
     The unit discharge portion  56  is arranged, between the first frame  51  and the second frame  52 , on a downstream side of the attachment portion  54  in the sheet conveying direction D 1 . The unit discharge portion  56 , which is configured with, for example, a conveyance roller pair extending in the sheet width direction D 2 , rotates around a roller shaft to conveyance the sheet S fed out from the decurling unit  57  further to the downstream side so as to be discharged. The sheet S discharged from the unit discharge portion  56  is carried, through the carry-in port CIP of the post-processing device  9  coupled to the relay conveyance device  3 , into the post-processing device  9 . 
     In the present embodiment, the receiving portion  55  and the unit discharge portion  56  are at the same position in the height direction D 3  (height position) as the carry-in port CIP of the post-processing device  9  in a state where the discharge unit  5  is supported by either the first unit supporting portion  44  or the second unit supporting portion  45 . “Having an same position” represents a state where a height position difference between each of the receiving portion  55  and the unit discharge portion  56  and the carry-in port CIP is within a predetermined allowable range. With a height position of the unit discharge portion  56  is same as that of the carry-in port CIP, discharging the sheet S horizontally from the unit discharge portion  56  enables the sheet to be introduced into the carry-in port CIP. This enables the discharge unit  5  to smoothly discharge the sheet S toward the carry-in port CIP of the post-processing device  9 . 
     Next, description will be made of the decurling unit  57  to be attached to the attachment portion  54  of the discharge unit  5  with reference to  FIG. 9  to  FIG. 13 .  FIG. 9  is a perspective view showing, in an enlarged manner, a first processing position adjustment portion  6  provided in the attachment portion  54  of the discharge unit  5 .  FIGS. 10A to 10C  are perspective views of the decurling unit  57 , and  FIG. 11  is a view schematically showing an internal structure of the decurling unit  57 .  FIG. 12  and  FIG. 13  are exploded perspective views of a second processing position adjustment portion  7  provided in the decurling unit  57 . 
     The decurling unit  57  is attached to the attachment portion  54  so as to be supported between the first frame  51  and the second frame  52  of the discharge unit  5 . The decurling unit  57  is a unit which subjects the sheet S introduced by the receiving portion  55  to the decurling processing and sends out the sheet S after the processing to the unit discharge portion  56 . The decurling unit  57  includes a housing  571 , a decurling belt  572 , a first supporting roller  573  and a second supporting roller  574  which form a pair of supporting rollers contained in the housing  571  and extending in the sheet width direction to rotate, a decurling roller  575 , and a tension roller  576 . 
     The housing  571  is a box-shaped (block-shaped) casing which houses each kind of structure configuring the decurling unit  57 . The housing  571  has, on a first side wall  57 A opposed to the second frame  52 , a first supported region portion  5711  and a second supported region portion  5712  spaced apart from each other in the sheet conveying direction D 1  set as shown in  FIG. 10A . On the first side wall  57 A of the housing  571 , the first supported region portion  5711  is arranged on the upstream side in the sheet conveying direction D 1  and the second supported region portion  5712  is arranged on the downstream side in the sheet conveying direction D 1 . On a second side wall  57 B opposed to the first frame  51 , the housing  571  has a third supported region portion  5713  and a fourth supported region portion  5714  set which are spaced apart from each other in the sheet conveying direction D 1 . On the second side wall  57 B of the housing  571 , the third supported region portion  5713  is arranged on the upstream side in the sheet conveying direction D 1  and the fourth supported region portion  5714  is arranged on the downstream side in the sheet conveying direction D 1 . 
     The housing  571  is supported by the second frame  52  in the first supported region portion  5711  and the second supported region portion  5712  and is supported by the first frame  51  in the third supported region portion  5713  and the fourth supported region portion  5714 . Specifically, the first supported region portion  5711  is provided with the second processing position adjustment portion  7  ( FIG. 10B ). The second supported region portion  5712  is provided with a supporting shaft  571 A ( FIG. 10C ) having a transmission gear which transmits driving force for driving the first supporting roller  573  to rotate. Further, the third supported region portion  5713  and the fourth supported region portion  5714  are each provided with a supporting protrusion  571 B. The housing  571  is supported by the second frame  52  at the second processing position adjustment portion  7  and the supporting shaft  571 A in the first supported region portion  5711  and the second supported region portion  5712 , and is as well supported by the first frame  51  at each supporting protrusion  571 B of the third supported region portion  5713  and the fourth supported region portion  5714 . 
     The decurling belt  572  is an endless belt having a width in the sheet width direction D 2 . The decurling belt  572  is extended over the first supporting roller  573  and the second supporting roller  574 . The decurling belt  572  circulates as the first supporting roller  573  and the second supporting roller  574  rotate. The first supporting roller  573  and the second supporting roller  574  are arranged to be opposed to each other in the housing  571 . The first supporting roller  573  is a driving roller extending along the sheet width direction D 2 . The first supporting roller  573  is rotatably supported by the first side wall  57 A and the second side wall  57 B which are both end portions of the housing  571  in a longitudinal direction. The first supporting roller  573  is driven to rotate by driving force of a driving motor input via the transmission gear of the supporting shaft  571 A to cause the decurling belt  572  to circulate. The second supporting roller  574  is a driven roller extending along the sheet width direction D 2 . The second supporting roller  574  is rotatably supported by the first side wall  57 A and the second side wall  57 B which are both end portions of the housing  571  in the longitudinal direction. The second supporting roller  574  is driven to rotate in conjunction with circulation of the decurling belt  572 . 
     A region, on an outer circumferential surface of the decurling belt  572 , opposed to the decurling roller  575 , the region being between the first supporting roller  573  and the second supporting roller  574 , becomes a conveyance region for conveying the sheet S. In other words, the first supporting roller  573  defines a downstream end of the decurling unit  57  in the sheet conveying direction D 1  and the second supporting roller  574  defines an upstream end of the decurling unit  57  in the sheet conveying direction D 1 . 
     The decurling roller  575  is a roller extending along the sheet width direction D 2 . The decurling roller  575  is rotatably supported by the first side wall  57 A and the second side wall  57 B which are both end portions of the housing  571  in the longitudinal direction. The decurling roller  575  is brought into contact, between the first supporting roller  573  and the second supporting roller  574 , with the outer circumferential surface of the decurling belt  572  by pressing, and is driven to rotate in conjunction with circulation of the decurling belt  572 . The decurling belt  572  forms, with the decurling roller  575 , a nip portion NP through which the sheet S passes. The nip portion NP has a curved shape along an outer circumferential surface of the decurling roller  575 . In other words, the curve-shaped nip portion NP has a radius of curvature equal to a radius of the decurling roller  575 . The sheet S on which an image has been formed passes through the curve-shaped nip portion NP while being conveyed by the circulating decurling belt  572 , resulting in being decurled. 
     The tension roller  576  is a roller which is provided on an inner circumferential surface side of the decurling belt  572  and applies tension to the decurling belt  572  while circulatably supporting the decurling belt  572 . The tension roller  576  extends along the sheet width direction D 2  and is driven to rotate in conjunction with circulation of the decurling belt  572 . 
     As described above, in the decurling unit  57 , the housing  571  has the first side wall  57 A supported by the second frame  52  in the first supported region portion  5711  and the second supported region portion  5712 , and has the second side wall  57 B supported by the first frame  51  in the third supported region portion  5713  and the fourth supported region portion  5714 . In the present embodiment, the first processing position adjustment portion  6  ( FIG. 9 ) and the second processing position adjustment portion  7  ( FIG. 10B ) are provided for adjusting an inclination of the decurling unit  57  attached to the attachment portion  54  of the discharge unit  5 . 
     The first processing position adjustment portion  6  and the second processing position adjustment portion  7  (both are processing unit adjustment portions) are set to be capable of adjusting an inclination in the height direction D 3  of the decurling unit  57  relative to the sheet width direction D 2  (a direction orthogonal to both directions of the height direction and the sheet conveying direction) such that the decurling unit  57  takes a predetermined horizontal reference position in a state where the decurling unit  57  is attached to the discharge unit  5 , and the discharge unit  5  is supported by the first unit supporting portion  44 . A position at which the first supporting roller  573  and the second supporting roller  574  are in line with the sheet width direction D 2  in the decurling unit  57  is a reference position of the decurling unit  57 . Adjusting the decurling unit  57  to take a reference position by the first processing position adjustment portion  6  and the second processing position adjustment portion  7  brings the first supporting roller  573  and the second supporting roller  574  to be parallel to each other. This enables meandering of the decurling belt  572  to be suppressed, the decurling belt being extended over the first supporting roller  573  and the second supporting roller  574 . As a result, generation of belt damage and abnormal sound due to meandering of the decurling belt  572  can be suppressed as soon as possible, as well as appropriately decurling the sheet S having passed through the nip portion NP formed on the decurling belt  572 . In the present embodiment, the first processing position adjustment portion  6  and the second processing position adjustment portion  7  are configured to be capable of adjusting a position of the first supported region portion  5711  in the housing  571  in the height direction D 3  relative to the second supported region portion  5712 , the third supported region portion  5713 , and the fourth supported region portion  5714 . 
     The first processing position adjustment portion  6  and the second processing position adjustment portion  7  are structures for adjusting a position in the height direction D 3  of the first supported region portion  5711  in the housing  571 , the first processing position adjustment portion  6  being provided in the second frame  52  and the second processing position adjustment portion  7  being provided in the first supported region portion  5711  of the housing  571 . 
     As described above, with the second processing position adjustment portion  7  provided in the first supported region portion  5711  and the supporting shaft  571 A provided in the second supported region portion  5712 , the first side wall  57 A of the housing  571  is supported by the second frame  52 . With the supporting protrusion  571 B provided in each of the third supported region portion  5713  and the fourth supported region portion  5714 , the second side wall  57 B of the housing  571  is supported by the first frame  51 . 
     The first supported region portion  5711  of the housing  571 , which will be described later, is supported by the second frame  52  as a result of contact of a cam member  71  in the second processing position adjustment portion  7  with a contact target portion  621  as shown in  FIG. 9 ,  FIG. 12 , and  FIG. 13 . This case brings about a state where a barrel  732  of a fixing pin  73  in the second processing position adjustment portion  7  is inserted into a first notched portion  52 A of the second frame  52 . The first notched portion  52 A has a tolerance with the barrel  732  in the sheet conveying direction D 1  and the height direction D 3 . Specifically, the first supported region portion  5711  of the housing  571  is supported by the second frame  52  via the second processing position adjustment portion  7  in a state where displacement in the sheet conveying direction D 1  and the height direction D 3  is allowed at the time of position adjustment in the height direction D 3  by the second processing position adjustment portion  7 . 
     The second supported region portion  5712  of the housing  571  is supported by the second frame  52  by the insertion of the supporting shaft  571 A into a positioning hole provided in the second frame  52 . The positioning hole has a tolerance with the supporting shaft  571 A neither in the sheet conveying direction D 1  nor in the height direction D 3 . Specifically, the second supported region portion  5712  of the housing  571  is supported by the second frame  52  via the supporting shaft  571 A in a state where displacement in the sheet conveying direction D 1  and the height direction D 3  is regulated. 
     The third supported region portion  5713  of the housing  571  is supported by the first frame  51  by the insertion of the supporting protrusion  571 B into a supporting hole provided in the first frame  51 . The supporting hole is a long hole extending in the sheet conveying direction D 1  and has no tolerance with the supporting protrusion  571 B in the height direction D 3  but has a tolerance in the sheet conveying direction D 1 . Specifically, the third supported region portion  5713  of the housing  571  is supported by the first frame  51  via the supporting protrusion  571 B in a state where displacement in the sheet conveying direction D 1  is allowed and displacement in the height direction D 3  is regulated. 
     The fourth supported region portion  5714  of the housing  571  is supported by the first frame  51  by the insertion of the supporting protrusion  571 B into a positioning hole provided in the first frame  51 . The positioning hole has a tolerance with the supporting protrusion  571 B neither in the sheet conveying direction D 1  nor in the height direction D 3 . Specifically, the fourth supported region portion  5714  of the housing  571  is supported by the first frame  51  via the supporting protrusion  571 B in a state where displacement in the sheet conveying direction D 1  and the height direction D 3  is regulated. 
     Since supporting of the first to fourth supported region portions  5711 ,  5712 ,  5713 , and  5714  in the housing  571  by each of the frames  51  and  52  is conducted in the above manner, the housing  571  will have no torsion caused by positional deviation in the sheet conveying direction D 1  and will have torsion caused by positional deviation in the height direction D 3 . When torsion is generated in the housing  571 , the first supporting roller  573  and the second supporting roller  574  will be arranged in a relation of torsional position, so that the decurling belt  572  will meander. For preventing torsion of the housing  571  as a cause of meandering of the decurling belt  572 , it is necessary to adjust a position of the first supported region portion  5711  in the height direction D 3  by a position adjustment portion of at least either the first processing position adjustment portion  6  or the second processing position adjustment portion  7 . 
     The first processing position adjustment portion  6  includes a first board body  61  and a second board body  62  as shown in  FIG. 9 . The first processing position adjustment portion  6  is provided in a region part of the attachment portion  54  in the second frame  52  of the discharge unit  5 . 
     The region part of the attachment portion  54  in the second frame  52 , the region part being a part where the first processing position adjustment portion  6  is provided, has the first notched portion  52 A and a second notched portion  52 B which are notched downward from an upper side edge in the height direction D 3 , and a scale portion  52 C formed near the first notched portion  52 A. Into the first notched portion  52 A, the barrel  732  of the fixing pin  73  is inserted, the fixing pin being in the second processing position adjustment portion  7  provided in the first supported region portion  5711  of the housing  571 . In this state, the first supported region portion  5711  of the housing  571  is supported by the second frame  52  via the second processing position adjustment portion  7 . Additionally, the supporting shaft  571 A provided in the second supported region portion  5712  of the housing  571  is inserted into the second notched portion  52 B. In this state, the second supported region portion  5712  of the housing  571  is supported by the second frame  52  via the supporting shaft  571 A. The scale portion  52 C, which will be detailed later, serves as a criterion for an amount of movement when the first board body  61  of the first processing position adjustment portion  6  is moved along the sheet conveying direction D 1 . 
     The first board body  61  is a substantially rectangular board body attached to the second frame  52  so as to be movable along the sheet conveying direction D 1 . The first board body  61  is attached on an upper side of the scale portion  52 C in the second frame  52 . The first board body  61  has a first protrusion pin  611 , a second protrusion pin  612 , and a positioning hole  613 . 
     The first protrusion pin  611  is a pin protruding from the first board body  61  toward the first frame  51  and is inserted into an insertion hole  622  of the second board body  62  to be described later. The second protrusion pin  612  is a pin protruding from the first board body  61  toward the second frame  52 . The second protrusion pin  612  is inserted into a pin guide hole formed in the second frame  52 . The positioning hole  613  is a long hole extending along the sheet conveying direction D 1 . After position adjustment in the height direction D 3  of the first supported region portion  5711  in the housing  571  by the first processing position adjustment portion  6 , when positioning the first board body  61  with respect to the second frame  52  and fixing the same, a screw member SC is inserted into the positioning hole  613 . 
     In the first board body  61  having the above configuration, the second protrusion pin  612  is inserted in the pin guide hole of the second frame  52  in a state where the first protrusion pin  611  is inserted in the insertion hole  622  of the second board body  62 . In this manner, the first board body  61  is attached to the second frame  52  so as to be movable along the sheet conveying direction D 1 . When the first board body  61  is moved along the sheet conveying direction D 1  with the scale portion  52 C as a criterion for an amount of movement, the second protrusion pin  612  moves along the pin guide hole of the second frame  52 . 
     The second board body  62  is a substantially rectangular board body supported by the first board body  61  through the first protrusion pin  611  so as to be movable in the height direction D 3 . The second board body  62  is arranged so as to be opposed to the first notched portion  52 A in the second frame  52 . The second board body  62  has the contact target portion  621 , the insertion hole  622 , a pin interference avoiding hole  623 , and a third protrusion pin  624 . 
     The contact target portion  621  is a part set at an upper side edge in the height direction D 3  of the second board body  62 . With the contact target portion  621 , a cam surface  711  of the cam member  71  in the second processing position adjustment portion  7  contacts, the second processing position adjustment portion being in a state where the barrel  732  of the fixing pin  73  is inserted in the first notched portion  52 A. The third protrusion pin  624  is a pin protruding, toward the second frame  52 , in a region where the third protrusion pin  624  does not overlap the first board body  61  in the sheet width direction D 2  in the second board body  62 . The third protrusion pin  624  is inserted in the pin guide hole formed in the second frame  52 . 
     The insertion hole  622  extends along the sheet conveying direction D 1  so as to incline in the height direction D 3  relative to the sheet conveying direction D 1 . Specifically, the insertion hole  622  in the second board body  62  is a long hole extending while inclining in the height direction D 3  relative to the sheet conveying direction D 1 . In the present embodiment, the insertion hole  622  inclines to go upward from the downstream side toward the upstream side in the sheet conveying direction D 1  so as to have an upstream side edge positioned above a downstream side edge as shown in  FIG. 9 . In the second board body  62 , the first protrusion pin  611  of the first board body  61  is inserted in the insertion hole  622 . 
     Similarly to the insertion hole  622 , the pin interference avoiding hole  623  extends along the sheet conveying direction D 1  so as to incline in the height direction D 3  relative to the sheet conveying direction D 1 . The pin interference avoiding hole  623  is a hole portion which is positioned on an upper side of the insertion hole  622  for preventing the second board body  62  from interfering with the second protrusion pin  612  of the first board body  61 . 
     Although illustration is omitted in  FIG. 9 , the second board body  62  has positioning holes as long holes which are formed at a predetermined position on a lower side of the insertion hole  622  and at a predetermined position on an upper side of the pin interference avoiding hole  623  and extend in the height direction D 3 . After position adjustment in the height direction D 3  of the first supported region portion  5711  in the housing  571  by the first processing position adjustment portion  6 , when positioning the second board body  62  with respect to the second frame  52  and fixing the same, the screw member SC is inserted into the positioning hole. 
     In the second board body  62  having the above configuration, the first board body  61  is moved along the sheet conveying direction D 1  in a state where the first protrusion pin  611  of the first board body  61  is inserted in the insertion hole  622 . When the first board body  61  moves along the sheet conveying direction D 1 , movement force of the first protrusion pin  611  caused by the movement acts on the insertion hole  622  in the second board body  62 . Since the insertion hole  622  inclines in the sheet conveying direction D 1  relative to the height direction D 3 , the force acting on the insertion hole  622  by the first protrusion pin  611  causes the second board body  62  to move in the height direction D 3 . When the second board body  62  moves in the height direction D 3 , the third protrusion pin  624  moves along the pin guide hole of the second frame  52 . In the second board body  62 , an angle of inclination of the insertion hole  622  relative to the sheet conveying direction D 1  is set such that the second board body  62  has the same amount of movement in the height direction D 3  as an amount of movement of the first board body  61  along the sheet conveying direction D 1 . 
     Moving the first board body  61  along the sheet conveying direction D 1  to move the second board body  62  in the height direction D 3  is conducted by a worker. Using a predetermined jig, the worker checks the inclination of the second frame  52 , moves the first board body  61  according to the inclination while watching the scale portion  52 C, and adjusts a position, in the height direction D 3 , of the contact target portion  621  set in the second board body  62 . 
     As described above, in the first processing position adjustment portion  6 , by the movement in the height direction D 3  according to the movement of the first board body  61  along the sheet conveying direction D 1 , the second board body  62  is allowed to move the cam member  71  of the second processing position adjustment portion  7  in the height direction D 3 , the cam member having the cam surface  711  which contacts the contact target portion  621 . This enables the second board body  62  to adjust a position of the first supported region portion  5711  in the housing  571  in the height direction D 3 , the first supported region portion  5711  being a portion in which the second processing position adjustment portion  7  having the cam member  71  as a part of the configuration is provided. At the time of moving the second board body  62  in the height direction D 3  according to movement of the first board body  61  along the sheet conveying direction D 1 , a position in the height direction D 3  of the first supported region portion  5711  in the housing  571  is adjusted such that the decurling unit  57  maintains the reference position. This brings the first supporting roller  573  and the second supporting roller  574  to be parallel to each other, thereby enabling meandering of the decurling belt  572  extended over the first supporting roller  573  and the second supporting roller  574  to be suppressed. 
     The second processing position adjustment portion  7  is provided in the first supported region portion  5711  in the housing  571  ( FIG. 10B ). The second processing position adjustment portion  7  includes the cam member  71 , a holding member  72 , and the fixing pin  73  as shown in  FIG. 12  and  FIG. 13 . In the second processing position adjustment portion  7 , the fixing pin  73 , the cam member  71 , and the holding member  72  are aligned in order from the outer side toward the inner side in the sheet width direction D 2 . In other words, in the second processing position adjustment portion  7 , the cam member  71  is sandwiched between the holding member  72  and the fixing pin  73 . 
     The cam member  71  is a cam having the cam surface  711  with which the predetermined contact target portion  621  set in the second frame  52  contacts. In the cam member  71 , the cam surface  711  is zoned into a plurality of cam regions  711 A,  711 B,  711 C,  711 D,  711 E, and  711 F having different radii and arranged at an equal interval with a predetermined interval in a circumferential direction. In the example shown in  FIG. 12  and  FIG. 13 , the cam surface  711  is zoned into the six cam regions of  711 A,  711 B,  711 C,  711 D,  711 E, and  711 F and is configured such that each cam region has a radius gradually changing toward one direction as a circumferential direction. The cam member  71  has a round-shaped through hole  712  formed at a central portion, as the center of a radius, of the cam surface  711  and a columnar protrusion portion  713  formed in a side surface portion to protrude to a side where the holding member  72  is arranged. 
     The holding member  72  is provided to protrude from the first supported region portion  5711  of the housing  571  toward the second frame  52  and holds the cam member  71 . The holding member  72  has a columnar base portion  721 , a flange portion  722 , and a boss portion  723 . 
     In the holding member  72 , the base portion  721  is a part having one end portion  721 A fixedly provided in the first supported region portion  5711  of the housing  571 . The flange portion  722  is a part provided in the other end portion of the base portion  721  so as to outwardly protrude from an outer circumferential surface of the base portion  721 . The flange portion  722  has, on an opposed surface  722 A which is opposed to the cam member  71 , a plurality of fit-in recessed portions  722 B in which the protrusion portions  713  of the cam member  71  can engage. The number of the fit-in recessed portions  722 B is the same as the number of cam regions on the cam surface  711  of the cam member  71 . Specifically, six fit-in recessed portions  722 B are formed at an equal interval in a circumferential direction of the opposed surface  722 A of the flange portion  722  so as to correspond to the cam surface  711  zoned into the six cam regions  711 A,  711 B,  711 C,  711 D,  711 E, and  711 F. The boss portion  723  is a cylindrical part provided on the opposed surface  722 A of the flange portion  722 . A female screw portion is formed in an inner circumferential surface  723 A of the boss portion  723 . The holding member  72  configured with the base portion  721 , the flange portion  722 , and the boss portion  723  has the one end portion  721 A of the base portion  721  fixedly provided to the first supported region portion  5711  of the housing  571 , has any one of the fit-in recessed portions  722 B of the flange portion  722  be fitted in by the protrusion portion  713  of the cam member  71 , and holds the cam member  71  in a state where the boss portion  723  is inserted in the through hole  712  of the cam member  71 . 
     The fixing pin  73  is attached to the holding member  72  with the cam member  71  sandwiched with the holding member  72 , thereby fixing the cam member  71  to the holding member  72 . The fixing pin  73  has a head portion  731 , a screw portion  733  in which a male screw portion is formed, and the barrel  732  provided between the head portion  731  and the screw portion  733  and coupling the both portions. The fixing pin  73  is attached to the holding member  72  as a result of screwing of the male screw portion of the screw portion  733  with the female screw portion formed in the inner circumferential surface  723 A of the boss portion  723  in a state where the boss portion  723  is inserted in the through hole  712  to hold the cam member  71  by the holding member  72 . In a state where the fixing pin  73  is attached to the holding member  72  as a result of screwing of the screw portion  733  with the boss portion  723 , the barrel  732  of the fixing pin  73  presses the cam member  71  to the holding member  72 . In this manner, the fixing pin  73  fixes the cam member  71  to the holding member  72 . 
     As described above, the second processing position adjustment portion  7  is provided in the first supported region portion  5711  of the housing  571 . In the second processing position adjustment portion  7 , a position of the fit-in recessed portion  722 B in which the protrusion portion  713  of the cam member  71  fits determines a cam region of the cam surface  711 , the cam region coming into contact with the contact target portion  621  set in the second board body  62  of the first processing position adjustment portion  6 . The cam member  71  enables adjustment of a position, in the height direction D 3 , of the first supported region portion  5711  in the housing  571  by a change of a cam region contacting the contact target portion  621  in the plurality of cam regions  711 A,  711 B,  711 C,  711 D,  711 E, and  711 F of the cam surface  711 . At the time of changing, on the cam surface  711  of the cam member  71 , a cam region contacting the contact target portion  621 , a position in the height direction D 3  of the first supported region portion  5711  in the housing  571  is adjusted such that the decurling unit  57  maintains the reference position. Since this brings the first supporting roller  573  and the second supporting roller  574  to be parallel to each other, meandering of the decurling belt  572  extending over the first supporting roller  573  and the second supporting roller  574  can be suppressed. 
     The work of adjusting a position in the height direction D 3  of the first supported region portion  5711  in the housing  571  by the second processing position adjustment portion  7  is conducted by a worker. Using a predetermined jig, the worker checks whether meandering of the decurling belt  572  has occurred or not, and when meandering has occurred, switches the fit-in recessed portion  722 B in which the protrusion portion  713  of the cam member  71  fits. This switching work enables change of a cam region of the cam surface  711 , the cam region contacting the contact target portion  621  in the cam member  71 . In this manner, a position in the height direction D 3  of the first supported region portion  5711  in the housing  571  can be adjusted. 
     In the discharge unit  5  configured to have the decurling unit  57  attached to the attachment portion  54 , simply changing the unit supporting portion which supports the discharge unit  5  between the first unit supporting portion  44  and the second unit supporting portion  45  according to a height position of the carry-in port CIP of the post-processing device  9  might cause the decurling unit  57  to take a position different from a predetermined reference position. In a case where the decurling unit  57  takes a position different from the reference position, appropriate decurling processing for the sheet S cannot be conducted. Therefore, the relay conveyance device  3  according to the present embodiment includes the discharge adjustment mechanism  8  ( FIG. 5 ). 
     The discharge adjustment mechanism  8  (a discharge unit adjustment mechanism) is a mechanism set to be capable of adjusting an inclination of the discharge unit  5  in the height direction D 3  relative to the sheet width direction D 2 . The discharge adjustment mechanism  8  is set to be capable of adjusting an inclination of the discharge unit  5 , in more detail, a height direction inclination of the discharge unit  5  in the sheet width direction such that the decurling unit  57  maintains the predetermined reference position in a state where the decurling unit  57  is adjusted to the reference position by the first processing position adjustment portion  6  or the second processing position adjustment portion  7  and is supported by the discharge unit  5  in either case where the discharge unit  5  is supported by the first unit supporting portion  44  or by the second unit supporting portion  45 . The discharge adjustment mechanism  8  is set to be capable of adjusting an inclination of the discharge unit  5  by adjusting a position in the height direction D 3  of any one supported portion among the first supported portion  511  and the second supported portion  512  of the first frame  51  and the third supported portion  521  and the fourth supported portion  522  of the second frame  52 . In the present embodiment, the discharge adjustment mechanism  8  is set to be capable of adjusting an inclination of the discharge unit  5  by adjusting a position in the height direction D 3  of the first supported portion  511  of the first frame  51 . This enables change of the unit supporting portion which supports the discharge unit  5  between the first unit supporting portion  44  and the second unit supporting portion  45  according to a height position of the carry-in port CIP of the post-processing device  9 , as well as enabling a reference position of the decurling unit  57  attached to the discharge unit  5  to be maintained. As a result, the discharge unit  5  is allowed to discharge the sheet S subjected to appropriate decurling processing in the decurling unit  57  toward the carry-in port CIP of the post-processing device  9 . 
     The discharge adjustment mechanism  8  will be described in more detail with reference to  FIG. 14  and  FIG. 15  in addition to  FIG. 5 .  FIGS. 14A to 14C  are views showing the discharge adjustment mechanism  8 .  FIGS. 15A to 15C  are views showing how an inclination of the discharge unit  5  is adjusted using the discharge adjustment mechanism  8 . 
     The discharge adjustment mechanism  8  is provided in the second unit supporting portion  45 . Specifically, the discharge adjustment mechanism  8  is provided in the first side pillar lower portion  4112  configuring the second unit supporting portion  45  in the first frame body  41  of the discharge portion main body  4  (see  FIG. 5 ). The discharge adjustment mechanism  8  includes the supporting pin  81  which supports the first supported portion  511  of the first frame  51  in the discharge unit  5 , a rotation shaft  82  provided in the first side pillar lower portion  4112 , and an adjustment board  83  attached to the first side pillar lower portion  4112 . 
     It is assumed that the discharge unit  5  is supported by the second unit supporting portion  45 . In this case, as is already described, the first frame  51  of the discharge unit  5  is supported by the second unit supporting portion  45  in a state where the supporting pin  81  of the discharge adjustment mechanism  8  is inserted in the first insertion hole  511 H of the first supported portion  511  and the supporting protrusion of the second frame body lower portion  422  is inserted in the second insertion hole  512 H of the second supported portion  512 . By contrast, the second frame  52  of the discharge unit  5  is supported by the second unit supporting portion  45  in a state where the supporting protrusion of the second supporting member  432  is inserted in the third insertion hole  521 H of the third supported portion  521  and the supporting protrusion of the second frame body lower portion  422  is inserted in the fourth insertion hole  522 H of the fourth supported portion  522 . The discharge adjustment mechanism  8  is set to be capable of adjusting a position in the height direction D 3  of the first supported portion  511  in the first frame  51  of the discharge unit  5  such that the decurling unit  57  is adjusted its position as the reference position after adjustment by the first processing position adjustment portion  6  and the second processing position adjustment portion  7  in a case where the discharge unit  5  is supported by the second unit supporting portion  45 . 
     With reference to  FIG. 14A , the supporting pin  81  is a pin member fixed to an attachment member  811 . The supporting pin  81  is held at the adjustment board  83  by the attachment of the attachment member  811  to the adjustment board  83  by a first screw member SC 1 . The supporting pin  81  supports the first supported portion  511  while being inserted in the first insertion hole  511 H of the first supported portion  511  in the first frame  51  of the discharge unit  5 . 
     The adjustment board  83  is a board body which holds the supporting pin  81 . The adjustment board  83  is attached to the first side pillar lower portion  4112  so as to be capable of rotating around the rotation shaft  82  provided in the first side pillar lower portion  4112  to protrude in the sheet conveying direction D 1 . The adjustment board  83  is set to be capable of adjusting a position in the height direction D 3  of the first supported portion  511  in the first frame  51  of the discharge unit  5  by displacing the supporting pin  81  in the height direction D 3  according to the rotation around the rotation shaft  82 . 
     The adjustment board  83  has a first supporting pin insertion hole  83 H 1 , a rotation shaft insertion hole  83 H 2 , a first positioning hole  83 H 3 , and a second positioning hole  83 H 4  as shown in  FIG. 14B . 
     The first supporting pin insertion hole  83 H 1  is arranged at an end portion of the adjustment board  83 , the end portion being on an upper side in the height direction D 3  and being on an outer side in the sheet width direction D 2 . The first supporting pin insertion hole  83 H 1 , which is a hole portion in which the supporting pin  81  is inserted, extends in the sheet width direction D 2  to incline in the height direction D 3  relative to the sheet width direction D 2 . Specifically, the first supporting pin insertion hole  83 H 1  is a long hole extending while inclining in the height direction D 3  relative to the sheet width direction D 2 . In the present embodiment, as shown in  FIG. 14 , the first supporting pin insertion hole  83 H 1  inclines to go upward from an inner side toward an outer side so as to have an outer side edge positioned above an inner side edge in the sheet width direction D 2 . 
     The rotation shaft insertion hole  83 H 2  is arranged, in the adjustment board  83 , on a lower side of the first supporting pin insertion hole  83 H 1  in the height direction D 3  and on an inner side of the same in the sheet width direction D 2 . The rotation shaft insertion hole  83 H 2  is a hole portion in which the rotation shaft  82  is inserted. The adjustment board  83  is attached to the first side pillar lower portion  4112  by a second screw member SC 2  in a state where the rotation shaft  82  is inserted in the rotation shaft insertion hole  83 H 2 . 
     The first positioning hole  83 H 3  is arranged, in the adjustment board  83 , at substantially the same position in the height direction D 3  as the first supporting pin insertion hole  83 H 1  and on an inner side in the sheet width direction D 2 . The first positioning hole  83 H 3  extends in the sheet width direction D 2  so as to incline in the height direction D 3  relative to the sheet width direction D 2  similarly to the first supporting pin insertion hole  83 H 1 . In the first positioning hole  83 H 3 , the first screw member SC 1  is inserted for attaching, to the adjustment board  83 , the attachment member  811  to which the supporting pin  81  is fixed. 
     The second positioning hole  83 H 4  is arranged, in the adjustment board  83 , at an end portion on a lower side in the height direction D 3 , the end portion being on an inner side in the sheet width direction D 2 . The second positioning hole  83 H 4  is a long hole extending along the height direction D 3 . In the second positioning hole  83 H 4 , the second screw member SC 2  is inserted for attaching the adjustment board  83  to the first side pillar lower portion  4112 . 
     As shown in  FIG. 14C , in the first side pillar lower portion  4112  provided with the discharge adjustment mechanism  8 , there are provided the rotation shaft  82  protruding in the sheet conveying direction D 1 , a scale portion  4112 A and a second supporting pin insertion hole  4112 H, and a first screw hole SC 1 H and a second screw hole SC 2 H. The scale portion  4112 A, which will be detailed later, becomes a criterion for an amount of rotation of the adjustment board  83  around the rotation shaft  82 . The second supporting pin insertion hole  4112 H is a hole portion in which the supporting pin  81  is inserted and is a long hole extending along the height direction D 3 . The first screw hole SC 1 H is a screw hole with which the first screw member SC 1  is screwed. The second screw hole SC 2 H is a screw hole with which the second screw member SC 2  is screwed. 
     The adjustment board  83  is attached to the first side pillar lower portion  4112  by the screwing of the second screw member SC 2  inserted in the second positioning hole  83 H 4  with the second screw hole SC 2 H. In the adjustment board  83  in this state, a rotation mark portion  83 P is arranged near the scale portion  4112 A to bring the rotation shaft  82  to be inserted in the rotation shaft insertion hole  83 H 2 . The attachment member  811  to which the supporting pin  81  is fixed is attached to the first side pillar lower portion  4112  via the adjustment board  83  by the screwing of the first screw member SC 1  inserted in the first positioning hole  83 H 3  with the first screw hole SC 1 H. In a state where the attachment member  811  is attached to the first side pillar lower portion  4112  via the adjustment board  83 , the supporting pin  81  is brought to be inserted in the first supporting pin insertion hole  83 H 1  and the second supporting pin insertion hole  4112 H. 
     The work of causing the adjustment board  83  to rotate around the rotation shaft  82  is conducted by a worker. In a state where the discharge unit  5  is supported by the second unit supporting portion  45 , the worker checks whether meandering of the decurling belt  572  has occurred in the decurling unit  57  or not using a predetermined special purpose jig. When the decurling belt  572  meanders, the worker conducts work for rotating the adjustment board  83  around the rotation shaft  82 . Before rotating the adjustment board  83 , the worker brings screwing of the first screw member SC 1  and the second screw member SC 2  with the first screw hole SC 1 H and the second screw hole SC 2 H into a released state. Then, the worker grasps a rotation operation portion  83 A provided on the adjustment board  83  while watching a position of the rotation mark portion  83 P relative to the scale portion  4112 A, thereby rotating the adjustment board  83 . In this manner, the supporting pin  81  attached to the adjustment board  83  via the attachment member  811  is displaced in the height direction D 3 . As a result, it is possible to adjust a position in the height direction D 3  of the first supported portion  511  in the first frame  51  of the discharge unit  5 , the first supported portion  511  being supported by the supporting pin  81 , such that the decurling unit  57  takes a predetermined reference position in the attachment portion  54  of the discharge unit  5  supported by the second unit supporting portion  45 . 
     With reference to  FIGS. 15A to 15C , description will be made of how the supporting pin  81  displaces in the height direction D 3  according to the rotation of the adjustment board  83 . 
     It is assumed that in a state where screwing of the first screw member SC 1  and the second screw member SC 2  with the first screw hole SC 1 H and the second screw hole SC 2 H is released, the adjustment board  83  is rotated around the rotation shaft  82  in a counterclockwise direction CD 1  ( FIG. 15B ). In this case, the first screw member SC 1  inserted in the first screw hole SC 1 H will near to an outer side edge in the sheet width direction D 2  of the first positioning hole  83 H 3  in the adjustment board  83 . Similarly, the second screw member SC 2  inserted in the second screw hole SC 2 H will near to an upper side edge in the height direction D 3  of the second positioning hole  83 H 4  in the adjustment board  83 . 
     When the adjustment board  83  is rotated in the counterclockwise direction CD 1 , rotational force of the adjustment board  83  acts on the supporting pin  81  inserted in the first supporting pin insertion hole  83 H 1 . Since the first supporting pin insertion hole  83 H 1  inclines to go upward from an inner side toward an outer side in the sheet width direction D 2 , the supporting pin  81  will be displaced upward in the height direction D 3  along the first supporting pin insertion hole  83 H 1 . The supporting pin  81  is inserted also in the second supporting pin insertion hole  4112 H of the first side pillar lower portion  4112 . Since the second supporting pin insertion hole  4112 H is a long hole extending in the height direction D 3 , when displaced along the first supporting pin insertion hole  83 H 1 , the supporting pin  81  is allowed to have displacement in the height direction D 3  while having displacement in the sheet width direction D 2  regulated. By the displacement of the supporting pin  81  in the height direction D 3  according to the rotation of the adjustment board  83 , a position of the first supported portion  511  in the height direction D 3  in the first frame  51  of the discharge unit  5  can be adjusted. 
     Next, it is assumed that in a state where screwing of the first screw member SC 1  and the second screw member SC 2  with the first screw hole SC 1 H and the second screw hole SC 2 H is released, the adjustment board  83  is rotated around the rotation shaft  82  in a clockwise direction CD 2  ( FIG. 15C ). In this case, the first screw member SC 1  inserted in the first screw hole SC 1 H will near to an inner side edge in the sheet width direction D 2  of the first positioning hole  83 H 3  in the adjustment board  83 . Similarly, the second screw member SC 2  inserted in the second screw hole SC 2 H will near to a lower side edge in the height direction D 3  of the second positioning hole  83 H 4  in the adjustment board  83 . 
     When the adjustment board  83  is rotated in the clockwise direction CD 2 , rotational force of the adjustment board  83  acts on the supporting pin  81  inserted in the first supporting pin insertion hole  83 H 1 . Since the first supporting pin insertion hole  83 H 1  inclines to go upward from an inner side toward an outer side in the sheet width direction D 2 , the supporting pin  81  will be displaced downward in the height direction D 3  along the first supporting pin insertion hole  83 H 1 . At this time, the supporting pin  81  is allowed to have displacement in the height direction D 3  by the second supporting pin insertion hole  4112 H while having displacement in the sheet width direction D 2  regulated. By the displacement of the supporting pin  81  in the height direction D 3  according to the rotation of the adjustment board  83 , a position of the first supported portion  511  in the height direction D 3  in the first frame  51  of the discharge unit  5  can be adjusted. 
     When adjustment of the position of the first supported portion  511  in the height direction D 3  in the first frame  51  of the discharge unit  5  is finished, screwing of the first screw member SC 1  and the second screw member SC 2  with the first screw hole SC 1 H and the second screw hole SC 2 H is fastened. This causes the adjustment board  83  to be fixed to the first side pillar lower portion  4112 , as well as fixing the attachment member  811  to the first side pillar lower portion  4112  via the adjustment board  83 . As a result, the supporting pin  81  fixed to the attachment member  811  is positioned with respect to the first side pillar lower portion  4112 . The supporting pin  81  positioned with respect to the first side pillar lower portion  4112  has displacement in the height direction D 3  regulated by the first supporting pin insertion hole  83 H 1  and has displacement in the sheet width direction D 2  regulated by the second supporting pin insertion hole  4112 H. 
     As described in the foregoing, in the relay conveyance device  3  according to the present embodiment, the discharge adjustment mechanism  8  is set to be capable of adjusting an inclination of the discharge unit  5  by adjusting a position in the height direction D 3  of the first supported portion  511  of the first frame  51 . This enables the unit supporting portion which supports the discharge unit  5  to be changed between the first unit supporting portion  44  and the second unit supporting portion  45  according to a height position of the carry-in port CIP of the post-processing device  9 , as well as enabling a reference position of the decurling unit  57  attached to the discharge unit  5  to be maintained. As a result, the discharge unit  5  is allowed to discharge the sheet S subjected to appropriate decurling processing in the decurling unit  57  toward the carry-in port CIP of the post-processing device  9 . 
     Although the present invention has been fully described by way of example with reference to the accompanying drawings, it is to be understood that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention hereinafter defined, they should be construed as being included therein.