Patent Publication Number: US-11661300-B2

Title: Medium transporting apparatus, processing apparatus, and recording system

Description:
The present application is based on, and claims priority from JP Application Serial Number 2019-175246, filed Sep. 26, 2019, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a medium transporting apparatus that transports a medium, a processing apparatus that includes the medium transporting apparatus, and a recording system that includes the processing apparatus. 
     2. Related Art 
     In processing apparatuses that perform a predetermined process on the medium, there is one that is configured to, after performing saddle stitching that binds a center of a plurality of stacked mediums to each other, form a booklet by folding the medium at a biding position. 
     Note that such a processing apparatus may be incorporated in a recording system configured to execute recording on a medium with a recording apparatus, a representative example being an ink jet printer, and saddle stitching and folding of the mediums, on which recording has been performed, in a continuous manner. 
     In such a processing apparatus, there is one that transports pre-process mediums to a mounting portion, on which the mediums are mounted, with a medium transporting apparatus, and performs saddle stitching after aligning the edge portions of the mediums mounted on the mounting portion by abutting the edge portions against the aligning portions. 
     For example, JP-A-2010-001149 discloses a configuration including a compiling tray corresponding to the mounting portion, an end guide corresponding to the aligning portions, paddles that move a sheet corresponding to the medium towards the end guide, and a pair of jogger fences that slide and move to align, in the width direction, the sheets piled up on the compiling tray. 
     In such a medium transporting apparatus described above, desirably, the stack of mediums is pressed against the mounting portion and the edges of the stack of mediums in the width direction, which is a direction intersecting the transport direction, are restricted so that the stack of mediums mounted on the mounting portion does not become disarranged. Furthermore, desirably, when the medium is sent onto the mounting portion, pressing of the stack of mediums towards the mounting portion is relieved for a minimum required time and the restriction towards the edges of the stack of mediums in the width direction is relieved. 
     Note that when sliding between the mediums are insufficient, as is the case, for example, in which ink jet printing is performed on the mediums and the frictional coefficient between the mediums are large, there are cases in which the downstream edge of the latest mounted medium in the transport direction does not reach the aligning portions and stops at an inappropriate position. However, in such cases as well, there are cases in which, the downstream edge of the medium, which has stopped at the inappropriate position, in the transport direction can reach the aligning portion by having the medium that has stopped at the inappropriate position be moved in the transport direction when the succeeding medium is sent. However, such an action cannot be expected to happen in the last medium of the plurality of mediums mounted on the mounting portion. Accordingly, there may be an incident in which a process is performed on the stack of mediums while the stack of mediums is not aligned in an appropriate manner. 
     SUMMARY 
     A medium transporting apparatus according to the present disclosure that overcomes the above issue includes a feeding member that transports a medium, a mounting portion that includes a support surface that, while being in an inclined position in which a downstream portion thereof is oriented downwards in a transport direction, supports the medium transported with the feeding member, the medium being mounted on the support surface, and a pressing portion configured to switch between a first state in which the pressing portion presses the medium, which is mounted on the mounting portion, from a downstream edge to a predetermined upstream area in the transport direction against the support surface, and a second state in which the pressing portion is, with respect to the first state, away from the support surface. In the medium transporting apparatus, when in a state waiting for the medium to be sent to the mounting portion, the pressing portion takes the first state, and when the medium is sent to the mounting portion, the pressing portion is switched to the second state from the first state and is returned to the first state from the second state after the medium is sent to the mounting portion, and in a case in which a plurality of mediums are mounted on the mounting portion, when a last medium is mounted on the mounting portion, a timing at which the pressing portion is returned to the first state from the second state is delayed with respect to a timing at which the pressing portion is returned to the first state from the second state when a medium before the last medium is mounted on the mounting portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a diagram illustrating an overall configuration of a recording system. 
         FIG.  2    is a side view of a saddle stitching and folding mechanism. 
         FIG.  3    is a side view of the saddle stitching and folding mechanism. 
         FIG.  4    is a side view of the saddle stitching and folding mechanism. 
         FIG.  5    is a side view of the saddle stitching and folding mechanism. 
         FIG.  6    is a side view of the saddle stitching and folding mechanism. 
         FIG.  7    is a plan view of a medium transporting apparatus. 
         FIG.  8    is a diagram of side guides and a stacker portion viewed in a transport direction. 
         FIG.  9    is a diagram illustrating an operation of aligning portions and the side guides. 
         FIG.  10    is a flowchart illustrating control of the aligning portions and the side guides. 
         FIG.  11    illustrates timing charts illustrating operations of the aligning portions and the side guides. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, an outline of the present disclosure will be described. 
     A medium transporting apparatus according to a first aspect includes a feeding member that transports a medium, a mounting portion that includes a support surface that, while being in an inclined position in which a downstream portion thereof is oriented downwards in a transport direction, supports the medium transported with the feeding member, the medium being mounted on the support surface, and a pressing portion configured to switch between a first state in which the pressing portion presses the medium, which is mounted on the mounting portion, from a downstream edge to a predetermined upstream area in the transport direction against the support surface, and a second state in which the pressing portion is, with respect to the first state, away from the support surface. In the medium transporting apparatus, when in a state waiting for the medium to be sent to the mounting portion, the pressing portion takes the first state, and when the medium is sent to the mounting portion, the pressing portion is switched to the second state from the first state and is returned to the first state from the second state after the medium is sent to the mounting portion, and in a case in which a plurality of mediums are mounted on the mounting portion, when a last medium is mounted on the mounting portion, a timing at which the pressing portion is returned to the first state from the second state is delayed with respect to a timing at which the pressing portion is returned to the first state from the second state when a medium before the last medium is mounted on the mounting portion. 
     In other aspect, A medium transporting apparatus comprising: a feeding member configured to transport a medium; a mounting portion that includes a support surface configured to support and stack the medium transported with the feeding member, the support surface being in an inclined position in which a downstream portion thereof is oriented downwards in a transport direction; and a pressing portion configured to switch between a first state for pressing the medium against the support surface at a predetermined upstream area in the transport direction from a downstream edge of the medium, and a second state for being away from the support surface with respect to the first state, wherein the pressing portion is configured to take the first state in waiting for the medium to be sent to the mounting portion, switch to the second state from the first state when the medium is sent to the mounting portion, and return to the first state from the second state after the medium is sent to the mounting portion, and the pressing portion is configured to delay a timing to return to the first state for a last medium of a plurality of mediums mounted on the mounting portion with respect to a timing to return to the first state for a second medium from the last medium. 
     According to the present aspect, in a case in which the plurality of mediums are mounted on the mounting portion, when the last medium is mounted on the mounting portion, the timing at which the pressing portion is returned to the first state from the second state, in other words, the timing at which the mediums are pressed against the support surface, is delayed with respect to the timing at which the pressing portion is returned to the first state from the second state when the medium before the last medium is mounted on the mounting portion; accordingly, the downstream edge of the last medium can be aligned in a further reliable manner and, ultimately, a more appropriate aligning result can be obtained. 
     Furthermore, compared with when the delay in the timing is applied to all of the mediums mounted on the mounting portion, a decrease in throughput can be suppressed. 
     Note that in the present specification, “the last medium when the plurality of mediums are mounted on the mounting portion” refers to the medium positioned at the top of the stack of mediums when a process such as binding is performed on the stack of mediums mounted on the mounting portion, or refers to the medium at the top of the stack of mediums when the stack of mediums is discharged as it is to another location from the mounting portion without performing any process on the stack of mediums. 
     A second aspect according to the first aspect includes a first side guide that opposes a first edge of the medium, which is mounted on the mounting portion, in a width direction that is a direction intersecting the transport direction, and a second side guide that opposes a second edge of the medium. In the second aspect, the first side guide and the second side guide are configured to be displaced from an aligning position that aligns the edges of the medium in the width direction to a separated position in which the first side guide and the second side guide are, with respect to the aligning position, away from the edges of the medium. When in the state waiting for the medium to be sent to the mounting portion, the first side guide and the second side guide are in the aligning position, and when the medium is sent to the mounting portion, the first side guide and the second side guide are displaced to the separated position from the aligning position and, subsequently, are returned to the aligning position from the separated position. In the case in which the plurality of mediums are mounted on the mounting portion, when the last medium is mounted on the mounting portion, a timing at which the first side guide and the second side guide are returned to the aligning position from the separated position is delayed with respect to a timing at which the first side guide and the second side guide are returned to the aligning position from the separated position when the medium before the last medium is mounted on the mounting portion. 
     According to the present aspect, in a case in which the plurality of mediums are mounted on the mounting portion, when the last medium is mounted on the mounting portion, the timing at which the first side guide and the second side guide are returned to the aligning position from the separated position is delayed with respect to the timing at which the first side guide and the second side guide are returned to the aligning position from the separated position when the medium before the last medium is mounted on the mounting portion; accordingly, the edges in the width direction can be aligned while the downstream edge of the last medium is aligned in a further reliable manner and, ultimately, a more appropriate aligning result can be obtained. 
     In a third aspect according to the second aspect, the pressing portion returns to the first state from the second state after the first side guide and the second side guide return to the aligning position from the separated position. 
     According to the present aspect, since the pressing portion returns to the first state from the second state after the first side guide and the second side guide return to the aligning position from the separated position, the pressing portion does not impede the aligning of the mediums by the first side guide and the second side guide. 
     A fourth aspect according to the second or third aspect includes an aligning portion that aligns downstream edges of the mediums, which are mounted on the mounting portion, in the transport direction, and a moving member that is positioned between the feeding member and the aligning portion in the transport direction and that is disposed so as to oppose the support surface, the moving member moving the medium towards the aligning portion by rotation thereof while being in contact with the medium. 
     Since the present aspect includes the moving member that is positioned between the feeding member and the aligning portion in the transport direction and that is disposed so as to oppose the support surface and since the moving member moves the medium towards the aligning portion by rotation thereof while being in contact with the medium, the downstream edge of the medium can reach the aligning portion in a more reliable manner and, ultimately, a more appropriate aligning result can be obtained. 
     In a fifth aspect according to any one of the second to fourth aspects, the timing at which the pressing portion returns to the first state from the second state and the timing at which the first side guide and the second side guide return to the aligning position from the separated position are controlled according to a condition in which the medium is sent to the mounting portion. 
     According to the present aspect, since the timing at which the pressing portion returns to the first state from the second state and the timing at which the first side guide and the second side guide return to the aligning position from the separated position are controlled according to the condition in which the medium is sent to the mounting portion, the downstream edge of the medium can reach the aligning portion in a more reliable manner and, ultimately, a more appropriate aligning result can be obtained. 
     A processing apparatus according to a sixth aspect includes the medium transporting apparatus according to any one of the first to fifth aspects, and a processing portion that performs a process on a medium mounted on the mounting portion. 
     According to the present aspect, an advantageous effect of either one of the first to fifth aspects described above can be obtained in the processing apparatus. 
     A recording system according to a seventh aspect includes a recording unit that performs recording on a medium, and the processing apparatus according to the sixth aspect that receives the medium and performs a process on the medium on which recording has been performed with the recording unit. 
     According to the present aspect, an advantageous effect of the sixth aspect described above can be obtained in the recording system. 
     Hereinafter, the present disclosure will be described in detail. 
     The X-Y-Z coordinate system illustrated in each drawing is a rectangular coordinate system in which the X-axis direction is the apparatus depth direction, the Y-axis direction is the apparatus width direction, and the Z-axis direction is the apparatus height direction illustrating the vertical direction. 
     Outline of Recording System 
     A recording system  1  illustrated in  FIG.  1    includes, as an example, from the right side towards the left side in  FIG.  1   , a recording unit  2 , an intermediate unit  3 , a first unit  5 , and a second unit  6  serving as a processing apparatus that is detachable from the first unit  5 . 
     The recording unit  2  performs recording on a transported medium. The intermediate unit  3  receives the medium, on which recording has been performed, from the recording unit  2  and delivers the medium to the first unit  5 , and mainly functions to facilitate drying of the medium. A drying portion  50  that performs drying on the medium that has been received therein, and an edge binding portion  42  that stacks the mediums, on which recording has been performed in the recording unit  2 , and that performs edge binding that binds the edges of the mediums are provided in the first unit  5 . A saddle stitching and folding mechanism  70  that binds and folds a center of a stack of mediums, on which recording have been performed in the recording unit  2 , into a booklet is provided in the second unit  6 . Note that a process of binding the center of the stack of mediums, on which recording has been performed, and a subsequent process of folding the stack of mediums are referred to simply as “saddle stitching”. 
     Hereinafter, the recording unit  2 , the intermediate unit  3 , the first unit  5 , and the second unit  6  will be described in detail in the above order. 
     Regarding Recording Unit 
     The recording unit  2  is configured as a multifunction machine that includes a printer portion  10  including a line head  20  serving as a recording portion that performs recording on a medium, and a scanner portion  11 . The line head  20  in the present exemplary embodiment is configured as a so-called ink jet recording head that performs recording by discharging ink, which is an example of a liquid, on a medium. 
     A cassette accommodation portion  14  that includes a plurality of medium storage cassettes  12  is provided below the printer portion  10 . A recording operation is performed by having the medium P stored in the medium storage cassette  12  pass through a feeding path  21  depicted by a solid line and be sent to a recording area of the line head  20 . The medium on which recording has been performed with the line head  20  is sent either to a first discharge path  22  that is a path through which the medium is discharged to a post-recording discharge tray  13  provided above the line head  20  or to a second discharge path  23  that is a path through which the medium is sent to the intermediate unit  3 . 
     Referring to  FIG.  1   , the first discharge path  22  is depicted by a broken line and the second discharge path  23  is depicted by a dot and dash line. The second discharge path  23  is provided to extend in the +Y direction of the recording unit  2  and delivers the medium to a receiving path  30  of the adjacent intermediate unit  3 . 
     Furthermore, the recording unit  2  includes a reversing path  24  depicted by a two-dot chain line in  FIG.  1    and is configured to perform a double-sided recording that performs recording on a second surface of the medium after performing recording on a first surface and reversing the medium. One or more pairs of rollers (not shown) that are examples of members that transport the medium are disposed in each of the feeding path  21 , the first discharge path  22 , the second discharge path  23 , and the reversing path  24 . 
     A control unit  25  that controls operations related to the transport and recording of the medium in the recording unit  2  is provided in the recording unit  2 . Note that the recording system  1  having the recording unit  2 , the intermediate unit  3 , the first unit  5 , and the second unit  6  mechanically and electrically coupled to each other is configured to transport the medium from the recording unit  2  to the second unit  6 . Note that the control unit  25  according to the present exemplary embodiment is configured to control various operations in the intermediate unit  3 , the first unit  5 , and the second unit  6  that are coupled to the recording unit  2 . 
     The recording unit  2  includes an operation unit  19 . The operation unit  19  is configured so that various settings and executed commands related to various processes in the recording unit  2 , the intermediate unit  3 , the first unit  5 , and the second unit  6  are input therethrough. The operation unit  19  further includes a display panel (not shown) configured to display various pieces of information thereon. 
     Regarding Intermediate Unit 
     A description of the intermediate unit  3  will be given next. The intermediate unit  3  illustrated in  FIG.  1    delivers the medium that the intermediate unit  3  has received from the recording unit  2  to the first unit  5 . The intermediate unit  3  is disposed between the recording unit  2  and the first unit  5 . The medium transported through the second discharge path  23  of the recording unit  2  is received into the intermediate unit  3  through the receiving path  30  and is transported towards the first unit  5 . Note that the receiving path  30  is depicted by a solid line in  FIG.  1   . 
     In the intermediate unit  3 , there are two transport paths that transport the medium. The first of the transport paths is a path that transports the medium from the receiving path  30 , through a first switchback path  33  depicted by a dotted line in  FIG.  1   , and to the merging path  33 . The second of the transport paths is a path that transports the medium from the receiving path  30 , through a second switchback path  32  depicted by a two-dot chain line in  FIG.  1   , and to the merging path  33 . 
     The first switchback path  31  is a path through which the medium is, after being received in an arrow A 1  direction, switched back in an arrow A 2  direction. The second switchback path  32  is a path through which the medium is, after being received in an arrow B 1  direction, switched back in an arrow B 2  direction. 
     The receiving path  30  is branched into the first switchback path  31  and the second switchback path  32  at a branching portion  35 . A flap (not shown) that switches the destination of the medium to either the first switchback path  31  or the second switchback path  32  is provided in the branching portion  35 . 
     Furthermore, the first switchback path  31  and the second switchback path  32  are merged at a merging portion  36 . Accordingly, the medium sent through either the first switchback path  31  or the second switchback path  32  can be delivered from the receiving path  30  to the first unit  5  through the merging path  33  common to the first switchback path  31  and the second switchback path  32 . 
     The intermediate unit  3  receives the medium from the recording unit  2  into the receiving path  30  while the latest recorded surface recorded with the line head  20  is faced upwards. The medium is flexed and reversed at the merging path  33  so that the latest recorded surface is facing down. 
     Accordingly, the medium in which the latest recorded surface is facing down is delivered to a first transport path  43  of the first unit  5  from the +Y direction of the intermediate unit  3 . 
     Note that one or more pairs of rollers (not shown) serving as members that transport the medium are disposed in each of the receiving path  30 , the first switchback path  31 , the second switchback path  32 , and the merging path  33 . 
     When recording is performed continuously on a plurality of mediums in the recording unit  2 , the mediums that have entered the intermediate unit  3  are alternately sent to the transport path passing through the first switchback path  31  and the transport path passing through the second switchback path  32 . With the above, the medium transportation throughput in the intermediate unit  3  can be increased. 
     Furthermore, as in the line head  20  of the present exemplary embodiment in which a liquid, specifically ink, is discharged on the medium to perform recording, when processes are performed in the subsequent first unit  5  and second unit  6  while the medium is wet, the recording surface may become worn, or the mediums may become aligned in a defective manner. 
     By delivering the medium, on which recording has been performed, from the recording unit  2  to the first unit  5  through the intermediate unit  3 , the time it takes for the medium on which recording has been performed to be sent to the first unit  5  can be set long and the medium can be dried further until the medium reaches the first unit  5  or the second unit  6 . 
     Regarding First Unit 
     A description of the first unit  5  will be given next. The first unit  5  illustrated in  FIG.  1    includes, at a lower portion thereof and in the −Y direction thereof, a receiving portion  41  that receives the medium from the intermediate unit  3 . The medium that is transported through the merging path  33  of the intermediate unit  3  enters the first unit  5  through the receiving portion  41  and is delivered to the first transport path  43 . 
     The first unit  5  includes a drying portion  50  that performs a process on the medium received through the receiving portion  41 , and the edge binding portion  42  that performs a process on the medium received through the receiving portion  41  or on which a process has been performed in the drying portion  50 . 
     The first unit  5  includes the first transport path  43  that sends the medium, which has been received through the receiving portion  41 , to the edge binding portion  42 , and a second transport path  44  that branches off from the first transport path  43  at a second branching portion D 2  and that sends the medium to the drying portion  50 . A flap (not shown) that switches the destination of the medium between the first transport path  43  and the second transport path  44  is provided in the second branching portion D 2 . 
     The edge binding portion  42  is a component that performs edge binding, which binds edge portions of the mediums such as, for example, a corner portion of each medium on one side, or one side of each medium. The edge binding portion  42  includes, as an example, a stapler. 
     The drying portion  50  is a component that performs drying on the medium. In the present exemplary embodiment, the drying portion  50  dries the medium by applying heat to the medium. While the detailed configuration of the drying portion  50  will be described later, the medium on which drying has been performed with the drying portion  50  is sent to either the edge binding portion  42  or the saddle stitching and folding mechanism  70  provided in the second unit  6 . 
     Furthermore, the first unit  5  includes a punching portion  46  that performs punching on the medium that has been received through the receiving portion  41 . The punching portion  46  is provided in the first transport path  43 , through which the medium that has been received into the first unit  5  passes, at a position that is close to the receiving portion  41 . The punching portion  46  is configured to perform punching at a position upstream of the first transport path  43 . Note that punching does not have to be performed on the medium, which has been received through the receiving portion  41 , with the punching portion  46 . 
     The medium received through the receiving portion  41  can be, through the first transport path  43  illustrated in  FIG.  1   , sent to a processing tray  48  or to the second unit  6  described later. In the processing tray  48 , the mediums are stacked on the processing tray  48  with rear edges thereof aligned in the transport direction. When a predetermined number of mediums P are stacked on the processing tray  48 , the edge binding portion  42  can perform edge binding on the rear edges of the mediums P. The first unit  5  includes a second discharge portion  62  that discharges the medium in the +Y direction. Note that the first unit  5  includes, other than the second discharge portion  62 , a first discharge portion  61  and a third discharge portion  63  that are also configured to discharge the medium. 
     The mediums on which a process has been performed by the edge binding portion  42  are discharged external to the first unit  5  through the second discharge portion  62  and are mounted on a first tray  40  that receives the medium discharged through the second discharge portion  62 . The first tray  40  is provided so as to protrude in the +Y direction from the first unit  5 . In the present exemplary embodiment, the first tray  40  includes a base portion  40   a  and an extension portion  40   b . The extension portion  40   b  is configured to be accommodated in the base portion  40   a.    
     Furthermore, a third transport path  45  that branches off from the first transport path  43  is coupled to the first transport path  43  at a third branching portion D 3  downstream of the second branching portion D 2 . A flap (not shown) that switches the destination of the medium between the first transport path  43  and the third transport path  45  is provided in the third branching portion D 3 . 
     An upper tray  49  is provided at an upper portion of the first unit  5 . The third transport path  45  continues from the third branching portion D 3  to the third discharge portion  63  described above. The medium transported through the third transport path  45  is discharged onto the upper tray  49  through the third discharge portion  63  with a discharge member (not shown). In other words, the medium received through the receiving portion  41  can be discharged to the upper tray  49  without passing through the edge binding portion  42 . 
     An overlapping path  64  that branches off from the first transport path  43  at a first branching portion D 1  and that merges with the first transport path  43  at a first merging portion G 1  is provided in the first transport path  43 . The overlapping path  64  constitutes an overlap processing portion  47  that sets two mediums on top of the other and sends the mediums to the drying portion  50  or to the edge binding portion  42 . A preceding medium and a succeeding medium can be transported downstream of the first merging portion G 1  in an overlapped manner by sending the preceding medium that is precedingly transported to the overlapping path  64  and by merging the succeeding medium transported through the first transport path  43  and the preceding medium with each other at the first merging portion G 1 . Note that a plurality of overlapping paths  64  may be provided in the overlap processing portion  47  so that three or more mediums are overlapped on each other and sent downstream. 
     In the first unit  5 , the overlap processing portion  47  is positioned vertically below the drying portion  50  and, when viewed in the vertical direction, or when viewed from the upper surface, the drying portion  50 , the edge binding portion  42 , and the overlap processing portion  47  have portions overlapping each other. Note that only the drying portion  50  and the overlap processing portion  47  may overlap each other, or only the edge binding portion  42  and the overlap processing portion  47  may overlap each other. 
     By disposing the drying portion  50 , the edge binding portion  42 , and the overlap processing portion  47  in such a positional relationship, an increase in the dimension of the apparatus in the horizontal direction can be suppressed and a reduction in the size of the apparatus can be achieved. 
     Note that one or more pairs of rollers (not shown) that are examples of members that transport the medium are disposed in each of the first transport path  43 , the second transport path  44 , and the third transport path  45  in the first unit  5 . 
     A description of the drying portion  50  provided in the first unit  5  will be given next. 
     The drying portion  50  includes a pair of heat rollers  51  serving as a drying portion that performs drying on the medium, and a loop-shaped transport path  52  that includes the pair of heat rollers  51  and that is configured to circulate and transport the medium. The second transport path  44  that has branched off from the first transport path  43  merges with the loop-shaped transport path  52  at a portion upstream of the pair of heat rollers  51 . Pair of transport rollers  68  provided in the second transport path  44  are configured to send and introduce the medium into the loop-shaped transport path  52 . 
     In the pair of heat rollers  51  in the present exemplary embodiment, the lower roller is a driving dry roller that is driven by a drive source (not shown), and the upper roller is a driven dry roller that is driven and rotated by the rotation of the driving dry roller. The driving dry roller is heated with a heater (not shown) so that the driving dry roller radiates heat to perform drying on the medium. Note that it is only sufficient that either one of the rollers constituting the pair of heat rollers  51  is heated; however, both of the rollers may be heated. 
     Note that the medium sent from the intermediate unit  3  enters through the receiving portion  41  of the first unit  5 , passes through the first transport path  43  into the second transport path  44  while the latest recorded surface is facing down. Subsequently, the medium is nipped between the pair of heat rollers  51  while the latest recorded surface is facing down. Accordingly, among the pair of heat rollers  51 , desirably, the heated roller comes in contact with the latest recorded surface of the medium. 
     The drying portion includes the loop-shaped transport path  52  and is configured to circulate and transport the medium in the loop-shaped transport path  52 ; accordingly, by circulating and transporting the medium a plurality of times, drying with the pair of heat rollers  51  can be performed a plurality of times. Accordingly, drying of the medium can be performed in a further reliable manner. 
     Furthermore, compared, for example, with when a plurality of pairs of heat rollers  51  are provided in the transport path, an increase in the cost of the apparatus can be suppressed and power consumption can be suppressed by including the loop-shaped transport path  52 . 
     In the recording system  1 , the heating with the pair of heat rollers  51  is controlled by the control unit  25  provided in the recording unit  2 . The control unit  25  is configured to control the heating of the pair of heat rollers  51  according to conditions. The conditions include, for example, other than the type, the stiffness, the thickness, the basis weight, and the like of the medium, the discharged amount of ink discharged while the recording unit  2  performed recording on the medium, whether recording on the medium is a double-sided recording or a single-sided recording, the environmental conditions such as the temperature, humidity, and the like when drying. 
     By controlling the heating by the pair of heat rollers  51  in accordance with such conditions, the medium can be dried in a more appropriate manner. The control of heating by the pair of heat rollers  51  includes, for example, whether heating is performed, the temperature when heating is performed, whether the remaining heat is used when heating is performed, the timing at which the pair of heat rollers  51  start heating, and the like. 
     Furthermore, in the pair of heat rollers  51 , one of the heat rollers, that is, the driven dry roller is urged against the other heat roller, that is, the driving dry roller with an urging member (not shown) such as a spring. The urging member is configured to change the urging force. The nip pressure of the pair of heat rollers  51  can be controlled by having the control unit  25  control an urging force changing member (not shown) that changes the urging force of the urging member. Desirably, the nip pressure of the pair of heat rollers  51  is changed according to conditions. Conditions that are similar to the conditions when controlling the heating by the pair of heat rollers  51  can be used. 
     A fourth transport path  59  is coupled to the loop-shaped transport path  52 . The fourth transport path  59  is a path that merges with the first transport path  43  at a second merging portion G 2  and that returns the medium, to which the drying has been performed with the pair of heat rollers  51 , to the first transport path  43 . 
     Furthermore, a fifth transport path  60  is coupled to the loop-shaped transport path  52 . The fifth transport path  60  is a path continuous to the first discharge portion  61 , and is a path that sends out the medium on which drying has been performed by the pair of heat rollers  51  towards the second unit  6 . 
     Furthermore, the first unit  5  includes a changeover flap (not shown) configured to switch between a first state in which the medium on which a process has been performed in the drying portion  50  is sent to the first discharge portion  61  and a second state in which the medium on which the process has been performed in the drying portion  50  is sent to the edge binding portion  42 . 
     Note that the drying portion  50  can be configured without the loop-shaped transport path  52 . 
     Furthermore, while in the present exemplary embodiment, the description has been given of the drying portion  50  that dries the medium by heating the medium from the outside, the drying portion  50  can be configured to dry the medium by applying air against the medium, for example. 
     Regarding Second Unit 
     A description of the second unit  6  will be given next. 
     The second unit  6  is provided below the first tray  40  of the first unit  5  so as to be detachable from the first unit  5 . 
     The medium delivered through the first discharge portion  61  of the first unit  5  to the second unit  6  is transported through a transport path  69  and is sent to the saddle stitching and folding mechanism  70 . The saddle stitching and folding mechanism  70  includes a stacking portion  71  serving as a mounting portion on which the medium is mounted. The stack of mediums mounted on the stacking portion  71  can be, after being bound at a saddle stitching position, folded at the saddle stitching position to be formed as a booklet. 
     The stack of mediums M, on which saddle stitching has been performed with the saddle stitching and folding mechanism  70 , is discharged to a second tray  65  illustrated in  FIG.  1   . The second tray  65  includes, at a distal end thereof in the +Y direction that is a medium discharge direction, a restriction portion  66 . The restriction portion  66  prevents the stack of mediums M discharged to the second tray  65  from protruding from the second tray  65  in the medium discharge direction or prevents the stack of mediums M from dropping off from the second tray  65 . Reference numeral  67  is a guide portion  67  that guides the stack of mediums M discharged from the second unit  6  to the second tray  65 . 
     Subsequently, referring mainly to  FIGS.  2  and  7   , the configuration of the saddle stitching and folding mechanism  70  will be described further. Note that hereinafter, a single medium will be referred to as a medium P, and a stack of mediums formed of a plurality of mediums P mounted on the stacking portion  71  will be referred to as a stack of mediums M. 
     Referring to  FIG.  2   , the saddle stitching and folding mechanism  70  includes a medium transporting apparatus  80  and a processing portion  70   a . The medium transporting apparatus  80  includes a pair of feed rollers  75  that are provided in the transport path  69  and that serve as a feeding member that transports the medium P, and the stacking portion  71  serving as a mounting portion on which the mediums P transported by the pair of feed rollers  75  are stacked. The processing portion  70   a  includes a binding mechanism  72  that, at a binding position, binds the stack of mediums M mounted on the stacking portion  71 , and a pair of folding rollers  73  serving as a folding member that folds the stack of mediums M at the binding position. 
     The pair of feed rollers  75  includes a driving roller  75   a  driven by a drive source (not shown), and a driven roller  75   b  driven and rotated by the rotation of the driving roller  75   a . The driving roller  75   a  rotates while being controlled by the control unit  25  (see  FIG.  1   ). 
     The reference sign G in  FIG.  2    indicates a merging position G, which is where the transport path  69  and the stacking portion  71  merge with each other. The medium P is sent from the transport path  69  to the stacking portion  71  with the pair of feed rollers  75 . 
     The stacking portion  71  includes a support surface  85  that supports the medium P transported by the pair of feed rollers  75  while being in a position in which downstream thereof in a transport direction +R is oriented downwards. The stacking portion  71  receives and stacks the mediums P between the support surface  85  and an opposing surface  86  that opposes the support surface  85 . 
     Furthermore, as illustrated in  FIGS.  2  and  7   , the medium transporting apparatus  80  includes aligning portions  76  that align downstream edges E 1  of a plurality of mediums P stacked on the stacking portion  71 , a first side guide  95  that opposes edges F 1  of the mediums P, which are stacked on the stacking portion  71 , in the −X direction, a second side guide  96  that opposes edges F 2  of the mediums P, which are stacked on the stacking portion  71 , in the +X direction, first paddles  81  and second paddles  82  that send the medium P in the transport direction +R, and first auxiliary paddles  83  and second auxiliary paddles  84  that assist the above paddles in sending the medium P. 
     The first paddles  81  are paddles positioned downstream of the pair of feed rollers  75  and are the first of the paddles positioned downstream of the pair of folding rollers  73  in the transport direction +R. The first paddles  81  are disposed so as to oppose the support surface  85  of the stacking portion  71 . 
     The second paddles  82  are positioned downstream of the first paddles  81  in the transport direction +R and are disposed so as to oppose the support surface  85  of the stacking portion  71 . 
     While being in contact with the medium P, the first paddles  81  and the second paddles  82  rotate in the clockwise direction in  FIG.  2    to move the medium P towards the aligning portions  76 . The first paddles  81  and the second paddles  82  rotate while being controlled by the control unit  25  (see  FIG.  1   ). 
     The first auxiliary paddles  83  are positioned downstream of the second paddles  82  in the transport direction +R and are disposed so as to oppose the support surface  85  of the stacking portion  71 . 
     The second auxiliary paddles  84  are positioned downstream of the first auxiliary paddles  83  in the transport direction +R and are disposed so as to oppose the support surface  85  of the stacking portion  71 . 
     The first auxiliary paddles  83  and the second auxiliary paddles  84  rotate in a direction that is the same as that of the first paddles  81  and the second paddles  82  described above, in other words, the first auxiliary paddles  83  and the second auxiliary paddles  84  rotate in the clockwise direction in  FIG.  2    to restrict the medium P from lifting from the support surface  85 . The first auxiliary paddles  83  and the second auxiliary paddles  84  rotate while being controlled by the control unit  25  (see  FIG.  1   ). 
     Note that when there is no particular need to distinguish between the first paddles  81 , the second paddles  82 , the first auxiliary paddles  83 , and the second auxiliary paddles  84  from each other, the above will be, for convenience sake, referred to hereinafter as a “paddle group”. 
     The aligning portions  76  configured to abut against the downstream edges E 1  of the mediums P, and abutting portions  77  configured to abut against upstream edges E 2  of the mediums P are provided in the stacking portion  71 . The aligning portions  76  and the abutting portions  77  are configured to move in both the transport direction +R and a direction −R opposite the transport direction +R with a driving member (not shown). 
     The aligning portions  76  align the downstream edges E 1  of the mediums P, and the abutting portions  77  align the upstream edges E 2  of the mediums P. The aligning portions  76  and the abutting portions  77  can be moved in the transport direction +R and the opposite direction −R using, for example, a rack and pinion mechanism, a belt moving mechanism, or the like that is operated by motive power of a drive source (not shown). 
     Furthermore, pressing portions  76   a  that press the mediums P from the downstream edges E 1  to a predetermined upstream area against the support surface  85  is integrally formed in the aligning portions  76 . The pressing portions  76   a  are configured to switch between a first state ( FIGS.  3  and  4   ) in which the pressing portions  76   a  press the stack of mediums M from the downstream edges E 1  to the predetermined upstream area against the support surface  85  with motive power of a drive source (not shown), and a second state ( FIGS.  2 ,  5 , and  6   ) in which the pressing portions  76   a  are, with respect to the first state, away from the support surface  85 . Note that for convenience sake, hereinafter, the first state of the pressing portions  76   a  will be referred to as a “closed state”, and the second state will be referred to as an “open state”. 
     The aligning portions  76 , the pressing portions  76   a , and the abutting portions  77  are controlled by the control unit  25  (see  FIG.  1   ). 
     Referring to  FIG.  7   , as described above, the first side guide  95  that opposes the edges F 1  in the −X direction of the mediums P stacked on the stacking portion  71 , and the second side guide  96  that opposes the edges F 2  in the +X direction of the mediums P stacked on the stacking portion  71  are provided in the stacking portion  71 . The first side guide  95  and the second side guide  96  are configured to move in the X-axis direction, which is a width direction of the medium P in the stacking portion  71 , with a driving member (not shown). The first side guide  95  and the second side guide  96  can be moved in the −X direction and the +X direction using, for example, a rack and pinion mechanism, a belt moving mechanism, or the like that is operated by motive power of a drive source (not shown). 
     The first side guide  95  and the second side guide  96  are configured to be displaced from an aligning position (states (b) and (c) in  FIG.  9   ) at which the edges F 1  and F 2  of the mediums P in the width direction are aligned by displacing the first side guide  95  and the second side guide  96  in directions approaching each other and by abutting the first side guide  95  and the second side guide  96  against the edges F 1  and F 2  of the mediums P stacked on the stacking portion  71  to a separated position (state (a) in  FIG.  9   ) at which the first side guide  95  and the second side guide  96  are moved, with respect to the aligning position, away from the edges F 1  and F 2 . Note that in  FIG.  9   , the first side guide  95  and the second side guide  96  displaced from the separated position to the aligning position are depicted in hatching, and the pressing portions  76   a  changed from the open state to the closed state are depicted in hatching. 
     The first side guide  95  and the second side guide  96  are controlled by the control unit  25  (see  FIG.  1   ). 
     Note that in the present exemplary embodiment, the first side guide  95  is, as illustrated in  FIG.  8   , shaped so that a predetermined area of the medium P in the X-axis direction including the edge F 1  enters therein when viewed in the transport direction and the second side guide  96 , in a similar manner, is shaped so that a predetermined area of the medium P in the X-axis direction including the edge F 2  enters therein. In  FIG.  8   , reference numeral  95   a  denotes a surface that abuts against the edge F 1  of the medium P, and reference numeral  96   a  denotes a surface that abuts against the edge F 2  of the medium P. 
     The stacking height of the stack of mediums M that can be stacked on the stacking portion  71  is limited by a distance T 1  between the support surface  85  and each of the surfaces of the first side guide  95  and the second side guide  96  that opposes the support surface  85 . Note that in the present exemplary embodiment, the distance between the surface of each pressing portion  76   a  that opposes the support surface  85  and the support surface  85  is also the same as the distance T 1  when the pressing portions  76   a  are in the open state. 
     Note that as illustrated in  FIG.  7   , various paddles constituting the paddle group are each provided in a plural number at appropriate intervals in the width direction of the medium. In the present exemplary embodiment, four first paddles  81  are provided in the width direction of the medium, and two second paddles  82  are provided in the width direction of the medium. Furthermore, four first auxiliary paddles  83  and four second auxiliary paddles  84  are provided in the width direction of the medium. Since the installed number of second paddles  82  is smaller than the installed number of the first paddles  81 , excessive transport of the medium with the second paddle  82  can be suppressed. 
     Note that in the present exemplary embodiment, four aligning portions  76  and four pressing portions  76   a  are provided in the width direction of the medium. Opening portions  71   a  are provided in the stacking portion  71  in a direction in which the aligning portions  76  move. The aligning portions  76  and the pressing portions  76   a  are disposed inside the opening portions  71   a . Since the medium P cannot be supported at where the opening portions  71   a  are located, each paddle is disposed at a position avoiding the opening portion  71   a.    
     In  FIG.  7   , a straight line CL depicts a center position in the X-axis direction or in the width direction of the medium. The paddles are, in the width direction of the medium, disposed at left and right symmetrical positions with respect to the center line CL. 
     In  FIG.  7   , reference numeral  91  is a motor that is a power source of a rotation shaft  81   a  or the first paddles  81 , reference numeral  92  is a motor that is a power source of rotation shafts  82   a ,  83   a , and  84   a , or the second paddles  82 , the first auxiliary paddles  83 , and the second auxiliary paddles  84 , and reference numeral  94  is a motive power transmitting portion that transmits driving force from a second motor  92  to the rotation shafts  82   a ,  83   a , and  84   a.    
     The binding mechanism  72  that binds the stack of mediums M, which are stacked on the stacking portion  71 , at a predetermined position in the transport direction +R is provided downstream of a merging position G in  FIG.  2   . The binding position according to the present exemplary embodiment is a center portion C of the stack of mediums M, which is stacked on the stacking portion  71 , in the transport direction +R. 
     The binding mechanism  72  is, for example, a stapler and binds the stack of mediums M with binding portions  72   a , which are an example of binding members. A plurality of binding portions  72   a  are provided at intervals in the X-axis direction, which is the width direction of the medium P. As described above, the binding mechanism  72  is configured to bind the stack of mediums M at the binding position, which is the center portion C of the stack of mediums M in the transport direction. 
     The pair of folding rollers  73  are provided downstream of the binding mechanism  72 . The opposing surface  86  is open at a position corresponding to a nip position N of the pair of folding rollers  73 , and an entering path  78  of the stack of mediums M from the stacking portion  71  to the pair of folding rollers  73  is formed. In the entering path  78 , an inclined surface that invites the center portion C, which is the binding position of the stack of mediums M, from the stacking portion  71  to the nip position N is formed in an entry hole in the opposing surface  86 . 
     A blade  74  configured to switch between a retracted state illustrated in  FIGS.  2  to  4  and  6    in which the blade  74  is retracted from the stacking portion  71 , and an advanced state illustrated in  FIG.  5    in which the blade  74  is advanced with respect to the binding position of the stack of mediums M stacked on the stacking portion  71  is provided on the opposite side of the pair of folding rollers  73  with respect to the stacking portion  71 . Reference numeral  79  is a hole portion  79  provided in the support surface  85 . The blade  74  is configured to pass through the hole portion  79 . 
     Regarding Transport of Medium During Saddle Stitching 
     Referring next to  FIGS.  2  to  8   , a basic flow in the second unit  6  in which the mediums P are transported, in which saddle stitching is performed, and in which the mediums P are discharged will be described. 
     In a state before the medium P is sent to the stacking portion  71 , in other words, in a standby state, the pressing portions  76   a  are in the closed state, and the first side guide  95  and the second side guide  96  are at the aligning position (the state (c) in  FIG.  9   ). With the above, disarrangement in the alignment of the mediums P that have already been mounted on the stacking portion  71 , in other words, disarrangement in the alignment of the stack of mediums M is suppressed. Note that hereinafter, when there is no need to distinguish between the first side guide  95  and the second side guide  96 , the first side guide  95  and the second side guide  96  will be referred to as a “pair of side guides” for convenience sake. 
     Furthermore, before the first medium P is sent to the stacking portion  71 , a state illustrated in  FIG.  2    in which the paddle group is stopped at a phase not in contact with the medium P is maintained. 
     When the medium P is sent to the stacking portion  71 , the pressing portions  76   a  are switched from the closed state to the open state, and the pair of side guides are displaced from the aligning position to the separated position (the state (a) in  FIG.  9   ). 
     Furthermore, when the medium P that has been sent to the stacking portion  71  is the first medium P, the paddle group is controlled to start rotating at a timing at which the medium P is sent to the stacking portion  71  with the pair of feed rollers  75  (see  FIG.  2   ). After the above, the paddle group continues to rotate until the last medium P is sent to the stacking portion  71  and until the stack of mediums M is discharged by the pair of folding rollers  73  after saddle stitching has been completed. 
     Referring to  FIG.  2   , the medium P that is sent to the stacking portion  71  moves towards the aligning portions  76  by its own weight and the downstream end E 1  is abutted against the aligning portions  76  by rotation of the paddle group. 
       FIG.  2    illustrates a state in which the plurality of mediums P overlapping each other on the stacking portion  71  are stacked as the stack of mediums M. 
     Note that when the medium P is received in the stacking portion  71 , each aligning portion  76  is, as illustrated in  FIG.  2   , disposed so that a distance from the merging position G between the transport path  69  and the stacking portion  71  to the aligning portion  76  is longer than the length of the medium P. With the above, the medium P is received in the stacking portion  71  without the upstream edge E 2  of the medium P transported through the transport path  69  remaining in the transport path  69 . The positions of the aligning portions  76  in the transport direction +R of the stacking portion  71  can be changed according to the size of the medium P. 
     Furthermore, at or after the timing at which the downstream edge E 1  of the medium P is assumed to have reached the aligning portions  76 , first, the pair of side guides are displaced from the separated position to the aligning position (the state (b) in  FIG.  9   ). Subsequently, the pressing portions  76   a  are switched from the open state to the closed state (the state (c) in  FIG.  9   , and  FIG.  3   ). 
     Transitioning of the states of the pair of side guides and the pressing portions  76   a  are repeated in the order of the state (a), the state (b), and the state (c) illustrated in  FIG.  9    until the last medium P is stacked on the stacking portion  71 . 
     Subsequently, when the last medium P has been stacked on the stacking portion  71 , binding that binds, with the binding portions  72   a , the center portion C of the stack of mediums M in the transport direction +R is performed. At the point when the transportation of the mediums P to the stacking portion  71  through the transport path  69  has been completed, as illustrated in  FIG.  3   , the position of the center portion C is deviated from the positions of the binding portions  72   a ; accordingly, as illustrated in  FIG.  4   , the aligning portions  76  are moved in the direction −R so that the center portion C of the stack of mediums M are disposed at a position that opposes the binding portions  72   a . Furthermore, the abutting portions  77  are moved in the direction +R so that the upstream edge E 2  of the stack of mediums M is abutted thereagainst. The downstream edge E 1  and the upstream edge E 2  of the stack of mediums M are aligned with the aligning portions  76  and the abutting portions  77 , and the center portion C of the stack of mediums M is bound with the binding portions  72   a.    
     After the stack of mediums M is bound with the binding portions  72   a , the pair of side guides are displaced from the aligning position to the separated position and the pressing portions  76   a  are switched from the closed state to the open state. Subsequently, as illustrated in the change from  FIG.  4    to  FIG.  2   , the aligning portions  76  are moved in the direction +R and the stack of mediums M is moved so that the bound center portion C is disposed at a position opposing the nip position N of the pair of folding rollers  73 . By only moving the aligning portions  76  in the direction +R while maintaining the state in which the stack of mediums M is in contact with the aligning portions  76  by its own weight, the stack of mediums M can be moved in the direction +R. Note that the abutting portions  77  can be moved in the direction +R to maintain the state in which the upstream edge E 2  of the stack of mediums M is in contact with the aligning portions  76 . 
     Subsequently, when the center portion C of the stack of mediums M is disposed at a position that opposes the nip position N of the pair of folding rollers  73 , as illustrated in  FIG.  5   , the blade  74  is advanced in a direction +S and the center portion C is bent towards the pair of folding rollers  73 . The bent center portion C of the stack of mediums M passes through the entering path  78  and the stack of mediums M is moved towards the nip position N of the pair of folding rollers  73 . 
     When the center portion C of the stack of mediums M becomes nipped by the pair of folding rollers  73 , the pair of folding rollers  73  rotate, and as illustrated in  FIG.  6   , the stack of mediums M is folded at the center portion C by the nip pressure of the pair of folding rollers  73  and is discharged towards the second tray  65  (see  FIG.  1   ). 
     Furthermore, after the center portion C is nipped by the pair of folding rollers  73 , the aligning portions  76  move in the direction +R and return to the state in  FIG.  2    in order to prepare for the reception of the next medium P in the stacking portion  71 . 
     Note that a crease forming member that adds a crease to the center portion C of the medium P can be provided in the transport path  69 . By creasing the center portion C, which becomes the position folded by the pair of folding rollers  73 , folding of the stack of mediums M at the center portion C is facilitated. 
     Regarding Operations of First Side Guide, Second Side Guide, and Pressing Portions 
     Referring subsequently to  FIGS.  10  and  11   , operations of the pair of side guides and the pressing portions  76   a  will be described in detail. 
     First, an issue that arises when the medium P is mounted on the stacking portion  71  will be described with reference to  FIG.  2   . As described above, that basic operation of the pressing portions  76   a  is, when in a state waiting for the medium P to be sent to the stacking portion  71 , the pressing portions  76   a  takes a closed state (the first state), and when the medium P is sent to the stacking portion  71 , the pressing portions  76   a  are switched from the closed state to the open state (the second state) and, subsequently, are returned to closed state from the open state. 
     Note that when the sliding between the mediums are insufficient, as is the case, in particular, in which ink jet printing is performed and the frictional coefficient between the mediums are large, there are cases in which the downstream edge E 1  of the latest mounted medium P does not reach the aligning portions  76  and stops at an inappropriate position. However, in such cases as well, there are cases in which the medium P that has stopped at the inappropriate position is moved in the transport direction +R by the succeeding medium P and the downstream edge E 1  of the medium P that has stopped at the inappropriate position reaches the aligning portions  76 . 
     However, such an action cannot be expected to happen in the last medium P of the plurality of mediums P mounted on the stacking portion  71 . Accordingly, saddle stitching may be performed on the stack of mediums M while the stack of mediums M is not aligned in an appropriate manner. 
     The control illustrated in  FIGS.  10  and  11    is executed to resolve such an issue. 
     In  FIG.  10   , the control unit  25  (see  FIG.  1   ) determines whether the medium P sent to the stacking portion  71  is the last medium P (step S 101 ), and if the medium P is not the last medium P (No in step S 101 ), selects a normal closing mode (step S 102 ) and if the medium P is the last medium P (Yes in step S 101 ), selects a delayed closing mode (step S 103 ). 
     Referring to  FIG.  11   , the normal closing mode and the delayed closing mode will be described in detail. 
     As described above, while waiting for the medium P to be sent to the stacking portion  71 , the pair of side guides are at the aligning position and the pressing portions  76   a  are in a closed state. Furthermore, when the medium P is sent to the stacking portion  71 , the pair of side guides are displaced from the aligning position to the separated position, and the pressing portions  76   a  are switched from the closed state to the open state. A timing at which the pair of side guides are displaced from the aligning position to the separated position is the same as a timing (timing t 1 ) at which the pressing portions  76   a  are switched from the closed state to the open state. 
     Furthermore, when the medium P is sent to the stacking portion  71 , first, the pair of side guides return to the aligning position from the separated position and, subsequently, the pressing portions  76   a  return to the closed state from the open state. With the above, the pressing portions  76   a  do not impede the aligning of the mediums P by the pair of side guides. 
     Furthermore, in the present exemplary embodiment, when the last medium P is mounted on the stacking portion  71 , the pressing portions  76   a  are controlled so that the timing to return to the closed state from the open state is delayed with respect to the timing at which the pressing portions  76   a  are returned to the closed state from the open state when the medium P before the last medium P is mounted on the stacking portion  71 . In  FIG.  11   , the chart for “first medium to second to last medium” illustrates the normal closing mode, and the chart for “last medium” illustrates the delayed closing mode. 
     In the normal closing mode, the timing at which the pressing portions  76   a  return to the closed state from the open state is timing t 3  in  FIG.  11   , and in the delayed closing mode, the timing at which the pressing portions  76   a  return to the closed state from the open state is timing t 5  in  FIG.  11   . The time between timing t 3  and timing t 5  is a delayed time W 2 . 
     With the above, the downstream edge E 1  of the last medium P can reach the aligning portions in a more reliable manner and, ultimately, a more appropriate aligning result can be obtained. 
     Furthermore, compared with when the delayed closing mode is applied to all of the mediums P mounted on the stacking portion  71 , a decrease in the throughput can be suppressed. 
     Furthermore, in a similar manner, when the last medium P is mounted on the stacking portion  71 , the pair of side guides are controlled so that the timing to return to the aligning position from the separated position is delayed with respect to the timing at which the pair of side guides are returned to the aligning position from the separated position when the medium P before the last medium P is mounted on the stacking portion  71 . 
     In the normal closing mode, the timing at which the side guides return to the aligning position from the separated position is timing t 2  in  FIG.  11   , and in the delayed closing mode, the timing at which the side guides return to the aligning position from the separated position is timing t 4  in  FIG.  11   . The time between timing t 2  and timing t 4  is a delayed time W 1 . 
     With the above, the side guides can align the edges of the mediums P in the width direction while the downstream edge E 1  of the last medium P has reached the aligning portions  76  in a more reliable manner and, ultimately, a more appropriate aligning result can be obtained. 
     Furthermore, it is also suitable for the timings (timings t 3  and t 5 ) at which the pressing portions  76   a  return to the closed state from the open state, and the timings (timings t 2  and t 4 ) at which the side guides return to the aligning position from the separated position are controlled according to the conditions in which the mediums P are sent to the stacking portion  71 . With the above, the downstream edges E 1  of the mediums P can reach the aligning portions  76  in a more reliable manner and, ultimately, a more appropriate aligning result can be obtained. 
     For example, when the frictional coefficient between the mediums P is high, the downstream edge E 1  of the last medium P does not easily reach the aligning portions  76 ; accordingly, suitably, the delayed times W 1  and W 2  described above are extended for a second medium P 2  in which the frictional coefficient between the mediums P is higher than that of a first medium P 1 . 
     Furthermore, when the mediums P become swollen, for example, since the gap above a medium Pm mounted last, in other words, gap T 2  in  FIG.  8    becomes small, it will be difficult for the downstream edge E 1  of the last medium Pm to reach the aligning portions  76 . Accordingly, when the mediums P are sent to the second unit  6  under a second condition in which the swelling of the mediums P is more prominent than when under a first condition, suitably, the delayed times W 1  and W 2  described above are extended. 
     Note that swelling of the medium P is swelling that occurs in a case in which, for example, the medium P is a sheet of paper and the ink is a liquid, when the sheet of paper absorbs the ink. The swelling of the medium P changes depending on the type of paper, the amount of ink absorbed in the paper, the temperature, the humidity, the length of drying time in the drying portion  50  (see  FIG.  1   ), and the like. 
     Specifically, when with plain paper in which the sheet is constituted of a single layer, the swelling at the time when the sheet is sent into the second unit  6  is more prominent than when with exclusive paper in which the sheet is constituted of a plurality of layers. 
     Furthermore, when the amount of discharged ink is a second amount that is larger than a first amount, the swelling at the time when the sheet is sent into the second unit  6  is prominent compared with when with the first amount. 
     Furthermore, when the drying time in the drying portion  50  (see  FIG.  1   ) is a second time that is shorter than a first time, the swelling at the time when the sheet is sent into the second unit  6  is prominent compared with when with the first time. 
     Furthermore, when the humidity is a second humidity that is higher than a first humidity, the swelling at the time when the sheet is sent into the second unit  6  is prominent compared with when with the first humidity. 
     Accordingly, when the mediums P are sent to the second unit  6  under the second condition in which the swelling of the mediums P is more prominent than when under a first condition, a more suitable aligning result can be obtained by extending the delayed times W 1  and W 2  described above. 
     Note that in the exemplary embodiment described above, the delayed closing mode is applied to only the last medium P; however, the application of the delayed closing mode may be started at a medium P before the last medium P. Furthermore, in so doing, as the mounting of the mediums P on the stacking portion  71  proceeds, the delayed times W 1  and W 2  may be increased. 
     Note that the intermediate unit  3  and the first unit  5  may be omitted from the recording system  1 . Furthermore, in so doing, the recording unit  2  and the second unit  6  may be individual units or the recording unit  2  and the second unit  6  may be integrated. In other words, the recording system may be configured inside a single housing including the line head  20  and the saddle stitching and folding mechanism  70 . 
     As described above, in the present specification, the recording system may be either a collection of individual units or a single unit configuration. 
     Note that the present disclosure is not limited to the exemplary embodiments described above and various modifications can be made within the scope of the disclosure stated in the claims, which are, naturally, also included in the scope of the present disclosure.