Patent Publication Number: US-11649130-B2

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

Description:
The present application is based on, and claims priority from JP Application Serial Number 2018-183525, filed Sep. 28, 2018, 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 medium processing apparatus that includes the medium transporting apparatus, and a recording system including the medium transporting apparatus. 
     2. Related Art 
     There are medium processing apparatuses that perform a stapling process, a punching process, and the like on a medium. For example, there is a medium processing apparatus that includes a medium transporting apparatus that matches and stacks end portions of transported mediums in a medium tray, and that performs processes such as a stapling process and the like on the mediums stacked on the medium tray. Note that such a medium processing apparatus is, in some cases, incorporated in a recording system that is capable of performing, in a sequential manner, a recording on a medium with a recording apparatus, a representative example thereof being an ink jet printer, and post-processes such as a stapling process and the like on the medium on which recording has been performed. 
     Regarding the medium transporting apparatus that matches the end portions of the mediums and stacks the mediums on the medium tray, there is one in JP-A-2010-6530, for example, including a medium tray on which a medium discharged from a discharge portion is mounted, width direction matching portions that move in a width direction that intersects a medium discharge direction and that match the end portions of the medium in the width direction mounted on the medium tray, an upstream matching portion that matches the end portion of the medium mounted on the medium tray at a portion upstream in the medium discharge direction of the discharge portion, and paddles that come into contact with the medium on the medium tray and that rotate to send the medium towards an upstream matching portion. The end portions of the medium in the width direction are matched with the width direction matching portions that move in the width direction, and the upper end portion of the medium is matched by having the paddles abut the medium against the upstream matching portion. Note that in JP-A-2010-6530, the discharge portion is a discharge roller 54, the medium tray is a loading tray 50, the width direction matching portion is a matching member 52, and the upstream matching portion is a stopper 53. 
     In such a medium transporting apparatus, there are cases in which the medium discharged on the medium tray becomes curled. When the medium is curled on the medium tray, the matching of the end portions of the medium in the width direction and the upstream end portion in the transport direction may not be performed appropriately. Accordingly, there are cases in which guide members that press the medium, which has not been matched and which has been discharged on the medium tray, from above the medium tray and that guide the medium to the medium tray are provided. 
     When the medium transporting apparatus is configured to transport a plurality of sizes of mediums and when a different guide member is provided for each medium size, the number of parts increases and leads to increase in cost and increase in size of the apparatus. Furthermore, by providing guide members at positions that match the medium with the smallest size so as to provide guide members that can oppose mediums of all sizes that can be transported with the medium transporting apparatus, various sizes of mediums can be guided with the common guide members; however, the positions in the width direction that are suitable for guiding the medium may differ according to the width size of the medium. For example, when a large-sized medium is held with guide members provided at positions corresponding to a small-sized medium, skewing occurs when the medium is moved with the paddles, and the end portions of the mediums may not be matched. 
     SUMMARY 
     A medium transporting apparatus of the present disclosure that overcomes the above issue includes a medium tray on which a medium discharged from a discharge portion that discharges the medium is mounted, a guide member that comes in contact with the medium that is to be discharged with the discharge portion, and that guides the medium to the medium tray, and a width direction matching member that matches an end portion of the medium, which has been discharged on the medium tray, in a width direction that intersects a discharge direction of the medium. In the medium transporting apparatus, the guide member and the width direction matching member move in the width direction in an interlocked manner. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic view of a recording system according to a first embodiment. 
         FIG.  2    is a sectional side view of the medium transporting apparatus according to the first embodiment. 
         FIG.  3    is a schematic sectional side view of the medium transporting apparatus according to the first embodiment. 
         FIG.  4    is a perspective view of the medium transporting apparatus according to the first embodiment. 
         FIG.  5    is a diagram illustrating a flow until a medium discharged from a pair of discharge rollers is mounted on a first tray. 
         FIG.  6    is a diagram illustrating a flow until the medium discharged from the pair of discharge rollers is mounted on the first tray. 
         FIG.  7    is a plan view illustrating an essential portion of the medium transporting apparatus. 
         FIG.  8    is a perspective view illustrating the essential portion of the medium transporting apparatus in an enlarged manner. 
         FIG.  9    is a perspective view of the first tray illustrating low frictional resistance members in an advanced state. 
         FIG.  10    is a perspective view of the first tray illustrating low frictional resistance members in a retracted state. 
         FIG.  11    is a perspective view of the first tray in which the low frictional resistance members in the advanced state are on the medium. 
         FIG.  12    is a perspective view illustrating a drive mechanism of the low frictional resistance members and a moving mechanism of width direction matching members. 
         FIG.  13    is a diagram illustrating a matching operation of the width direction matching members. 
         FIG.  14    is a diagram illustrating switching of the low frictional resistance members between the advanced state and the retracted state. 
         FIG.  15    is a plan view illustrating a state in which the width direction matching member is positioned on the innermost side in the width direction. 
         FIG.  16    is a perspective view illustrating an example of a configuration interlocking the guide member and the paddle with the movement of the width direction matching member. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, the present disclosure will be described in a schematic manner. 
     A medium transporting apparatus according to a first aspect includes a medium tray on which a medium discharged from a discharge portion that discharges the medium is mounted, a guide member that comes in contact with the medium that is to be discharged with the discharge portion, and that guides the medium to the medium tray, and a width direction matching member that matches an end portion of the medium, which has been discharged on the medium tray, in a width direction that intersects a discharge direction of the medium, in which the guide member and the width direction matching member move in the width direction in an interlocked manner. 
     According to the present aspect, since the guide member and the width direction matching member move in an interlocked state, the guide member and the width direction matching member can be disposed at appropriate positions in the width direction according to the size of the medium; accordingly, guiding of the medium with the guide member and the matching of the end portion of the medium in the width direction with the width direction matching member can both be performed appropriately. Since the present aspect can correspond to a plurality of sizes of mediums with a common guide member and a common width direction matching member, an increase in the number of parts and an increase in the cost or an increase in the size of the apparatus due to the increase in the number of parts can be suppressed. 
     In a second aspect according to the first aspect, the guide member is configured to switch between a retracted position that does not interrupt discharge of the medium discharged with the discharge portion and an advanced position in which the guide member is, relative to the retracted position, advanced in a direction approaching the medium tray. The guide member is positioned at the retracted position when the medium is transported in the discharge direction with the discharge portion and the guide member is displaced from the retracted position to the advanced position when the medium that has been discharged from the discharge portion is guided to the medium tray. 
     According to the present aspect, the guide member is configured to switch between a retracted position that does not interrupt discharge of the medium discharged with the discharge portion and an advanced position in which the guide member is, relative to the retracted position, advanced in a direction approaching the medium tray, the guide member is positioned at the retracted position when the medium is transported in the discharge direction with the discharge portion and the guide member is displaced from the retracted position to the advanced position when the medium that has been discharged from the discharge portion is guided to the medium tray; accordingly, the medium that is discharged from the discharge portion can be appropriately guided to the medium tray. 
     A third aspect according to the second aspect further includes an upstream end matching member that matches an upstream end portion of the medium, which has been discharged to the medium tray, in the discharge direction, and a paddle that comes in contact with the medium, which has been discharged to the medium tray, and that rotates. The paddle moves the medium towards the upstream end matching member. The paddle being interlocked with movements of the guide member and the width direction matching member moves in the width direction. 
     According to the present aspect, the medium can be abutted against the upstream end matching member and the upstream end portion of the medium can be matched by moving the medium towards the upstream end matching member with the paddle. Since the paddle moves in the width direction while being interlocked with the movements of the guide member and the width direction matching member, the paddle can be disposed at an appropriate position in the width direction corresponding to the size of the medium and, accordingly, the paddle can appropriately move the medium. 
     In a fourth aspect according to the third aspect, the width direction matching member, the guide member, and the paddle are provided on both sides with respect to a center in the width direction and are, in the width direction, disposed from an outside towards the center in an order of the width direction matching member, the guide member, and the paddle. 
     In the present aspect, the width direction matching member, the guide member, and the paddle are provided on both sides with respect to a center in the width direction and are, in the width direction, disposed from an outside towards the center in an order of the width direction matching member, the guide member, and the paddle; accordingly, the matching of the end portion of the medium in the width direction with the width direction matching member, and the guiding of the medium with the guide member, and the moving of the medium towards the upstream end matching member with the paddle can be performed appropriately. By disposing the paddle inside the guide member, the medium can be moved with the paddle while reliably suppressing curling of the medium. 
     In a fifth aspect according to the fourth aspect, the width direction matching member is configured to perform a matching operation that matches an end portion of the medium in the width direction by moving from a first position that is positioned outside the medium, which is mounted on the medium tray, in the width direction to a second position that is positioned inside the first position in the width direction, and the guide member and the paddle are configured to be switched to a state in which the guide member and the paddle are not interlocked with the movement of the width direction matching member when the matching operation is performed. 
     According to the present aspect, the guide member and the paddle can be configured not to move in an interlocked manner with the width direction matching member moving to perform the matching operation. 
     In a sixth aspect according to the third to fifth aspect, the width direction matching member, the guide member, and the paddle are disposed at positions that do not overlap each other in plan view. 
     According to the present aspect, the width direction matching member, the guide member, and the paddle are disposed at positions that do not overlap each other in plan view; accordingly, interference between the above members can be suppressed. 
     A medium processing apparatus according to a seventh aspect includes the medium transporting apparatus according to any one of the first to sixth aspect, and a processing portion that performs a predetermined process on the medium transporting apparatus mounted on the medium tray. 
     According to the present aspect, an effect similar to those of the first to sixth aspects can be obtained with the medium processing apparatus that includes the processing portion that performs the predetermined process on the medium mounted on the medium tray of the medium transporting apparatus. 
     A recording system according to an eighth aspect includes a recording unit that includes a recording member that performs recording on a medium, and a processing unit including a medium transporting apparatus according to any one of the first to sixth aspect, the medium transporting apparatus transporting the medium on which recording has been performed in the recording unit, and a processing portion that performs a predetermined process on the medium mounted on the medium tray. 
     According to the present aspect, an effect similar to those of the first to sixth aspects can be obtained with the recording unit that includes the recording member that performs recording on the medium, and the processing unit including the medium transporting apparatus, the medium transporting apparatus transporting the medium on which recording has been performed in the recording unit, and the processing portion that performs a predetermined process on the medium mounted on the medium tray. 
     First Embodiment 
     Hereinafter, a description of a first embodiment will be given with reference to the drawings. In the X-Y-Z coordinate system in each of the drawings, the X-axis direction is a width direction of a medium and indicates a depth direction of the apparatus, the Y-axis direction indicates a width direction of the apparatus, and the Z-axis direction indicates a height direction of the apparatus. 
     Outline of Recording System 
     A recording system  1  illustrated in  FIG.  1    serving as an example includes, from the right side towards the left side in  FIG.  1   , a recording unit  2 , an intermediate unit  3 , and a processing unit  4 . 
     The recording unit  2  includes a line head  10  serving as a “recording member” that performs recording on a 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 processing unit  4 . The processing unit  4  includes a medium transporting apparatus  30  that transports the medium on which recording has been performed in the recording unit  2 , and a processing portion  36  that performs a predetermined process on the medium mounted on a first tray  35  in the medium transporting apparatus  30 . 
     In the recording system  1 , the recording unit  2 , the intermediate unit  3 , and the processing unit  4  are coupled to each other and are configured to transport the medium from the recording unit  2  to the processing unit  4 . 
     The recording system  1  is configured so that a recording operation, which is performed on the medium with the recording unit  2 , the intermediate unit  3 , and the processing unit  4 , and other operations can be input from an operation panel (not shown). The operation panel can be, as an example, provided in the recording unit  2 . 
     Hereinafter, outlines of the configurations of the recording unit  2 , the intermediate unit  3 , and the processing unit  4  will be described in the above order. 
     Regarding Recording Unit 
     The recording unit  2  illustrated in  FIG.  1    is configured as a multifunction machine that includes a printer unit  5  and a scanner unit  6 . The printer unit  5  includes the line head  10  (the recording member) that performs recording by ejecting ink, which is a liquid, to the medium. In the present embodiment, the printer unit  5  is configured as a so-called ink jet printer that performs printing by ejecting ink, which is a liquid, to the medium from the line head  10 . 
     A plurality of medium storage cassettes  7  are provided in an apparatus lower portion of the recording unit  2 . The recording operation is performed by having the medium stored in one of the medium storage cassettes  7  pass through a feeding path  11  depicted by a solid line in the recording unit  2  in  FIG.  1    and by having the medium be sent to an area in which recording is performed by the line head  10 . The medium on which recording has been performed with the line head  10  is sent either to a first discharge path  12  that is a path through which the medium is discharged to a post-recording discharge tray  8  provided above the line head  10  or to a second discharge path  13  that is a path through which the medium is sent to the intermediate unit  3 . In the recording unit  2  in  FIG.  1   , the first discharge path  12  is depicted with a broken line and the second discharge path  13  is depicted with a dot and dash line. 
     Furthermore, the recording unit  2  includes a reversing path  14  depicted by a two-dot chain line in the recording unit  2  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 transport rollers (not shown) that are examples of members that transport the medium are disposed in each of the feeding path  11 , the first discharge path  12 , the second discharge path  13 , and the reversing path  14 . 
     A control unit  15  that controls operations related to the transport and the recording of the medium in the recording unit  2  is provided in the recording unit  2 . 
     Regarding Intermediate Unit 
     The intermediate unit  3  illustrated in  FIG.  1    is disposed between the recording unit  2  and the processing unit  4 . The intermediate unit  3  is configured to receive, through a receiving path  20 , the medium on which recording has been performed sent from the second discharge path  13  of the recording unit  2  and to transport the medium to the processing unit  4 . The receiving path  20  is depicted by a solid line in the intermediate unit  3  illustrated in  FIG.  1   . 
     In the intermediate unit  3 , there are two transport paths that transport the medium. The first transport path is a path through which the medium is transported from the receiving path  20  to a discharge path  23  through a first switchback path  21 . The second path is a path through which the medium is transported from the receiving path  20  to the discharge path  23  through a second switchback path  22 . 
     The first switchback path  21  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  22  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  20  is branched into the first switchback path  21  and the second switchback path  22  at a branching portion  24 . Furthermore, the first switchback path  21  and the second switchback path  22  are merged at a merging portion  25 . Accordingly, the medium sent from the receiving path  20  through either of the switchback paths can be delivered to the processing unit  4  through the common discharge path  23 . 
     One or more pairs of transport rollers (not shown) are disposed in each of the receiving path  20 , the first switchback path  21 , the second switchback path  22 , and the discharge path  23 . 
     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  21  and the transport path passing through the second switchback path  22 . With the above, the throughput of medium transportation in the intermediate unit  3  can be increased. 
     Note that the recording system  1  can be configured without the intermediate unit  3 . In other words, a configuration in which the recording unit  2  and the processing unit  4  are coupled to each other, and the medium on which recording has been performed in the recording unit  2  is directly sent to the processing unit  4  without passing through the intermediate unit  3  can be provided. 
     As in the present embodiment, when the medium on which recording has been performed in the recording unit  2  is sent to the processing unit  4  through the intermediate unit  3 , compared with when the medium is sent directly to the processing unit  4  from the recording unit  2 , the transport time is long; accordingly, the ink on the medium can be drier before the medium is transported to the processing unit  4 . 
     Regarding Processing Unit 
     The processing unit  4  illustrated in  FIG.  1    includes the medium transporting apparatus  30  and is configured so that the processing portion  36  performs a process on the medium transported in the medium transporting apparatus  30 . Examples of the processes performed by the processing portion  36  includes a stapling process and a punching process. 
     The medium is delivered to a transport path  31  of the processing unit  4  from the discharge path  23  of the intermediate unit  3  and is transported with the medium transporting apparatus  30 . A pair of transport rollers  32  that transport the medium are provided upstream of the transport path  31  in a transport direction (+Y direction). Furthermore, a pair of discharge rollers  33  serving as a “discharge portion” that discharges the medium to the first tray  35  described later is provided downstream of the transport path  31  in the transport direction. 
     Regarding Medium Transporting Apparatus 
     Referring hereinafter to the drawings, a detailed description of the medium transporting apparatus  30  will be given. 
     The medium transporting apparatus  30  illustrated in  FIG.  2    includes the first tray  35  and paddles  40 . The first tray  35  serving as a “medium tray” mounts thereon a medium P discharged with the pair of discharge rollers  33 , and includes upstream end matching members  38  serving as “matching portions” that match trailing edges E 1  of the mediums P at portions upstream in a discharge direction (the +Y direction) of the pair of discharge rollers  33 . The paddles  40  come in contact with the medium P discharged on the first tray  35 , rotate, and move the medium P towards the upstream end matching member  38 . 
     The pair of discharge rollers  33  discharge the medium P in the discharge direction that extends substantially towards the +Y direction. 
     Guide members  41  that come in contact with the medium P, which is discharged with the pair of discharge rollers  33 , from above and that guide the medium P to the first tray  35  are provided above the first tray  35 . The guide members  41  are configured to be displaced between, as illustrated in  FIG.  2   , a retracted position that does not interrupt the discharge of the medium P discharged with the pair of discharge rollers  33 , and as illustrated in  FIG.  3   , an advanced position in which the guide members  41  are, relative to the retracted position, advanced in a direction approaching the first tray  35 . In  FIG.  3   , the guide member  41  in the retracted position is depicted by a broken line. When the medium P is transported in the discharge direction with the pair of discharge rollers  33 , the guide members  41  are positioned in the retracted position illustrated in  FIG.  2   , and when the medium P discharged from the pair of discharge rollers  33  is guided to the first tray  35 , the guide members  41  are displaced from the retracted position illustrated by a broken line in  FIGS.  2  and  3    to the advanced position illustrated by a solid line in  FIG.  3   . 
     As illustrated in  FIGS.  2  and  3   , the paddles  40  and the guide members  41  overlap each other in the discharge direction of the medium P and, as illustrated in  FIG.  4   , are at positions shifted with respect to each other in the X-axis direction that is the width direction that intersects the discharge direction. In  FIG.  4   , a single paddle  40  and a single guide member  41  are disposed on both sides with respect to the center C in the width direction so as to be symmetrical against the center C. A paddle  40   a  and a guide member  41   a  are provided on a +X side with respect to the center C, and a paddle  40   b  and a guide member  41   b  are provided on a −X side with respect to the center C. 
     Each paddle  40  includes plate-shaped members, and a plurality of plate-shape members are attached at intervals along an outer circumference of a rotation shaft  40 A. A +Y side, which is downstream in the discharge direction, of each guide member  41  is attached to a pivot shaft  41 A, and a −Y side of the guide member  41  is configured to pivot as a free end. 
     Upper rollers  42  are provided above the first tray  35  and downstream of the paddles  40  and the guide members  41  in the discharge direction of the medium P. The upper rollers  42  are rollers that, together with lower rollers  43  provided on the first tray  35  side, nip a single or a plurality of mediums P mounted on the first tray  35  to discharge the single of the plurality of mediums P to a second tray  37 . 
     Referring to  FIGS.  2  and  3   , the second tray  37  that receives the medium discharged from the first tray  35  is provided in the +Y direction of the first tray  35 . 
     The medium P discharged with the pair of discharge rollers  33  is mounted on the first tray  35 . An upstream end portion of the medium P, which has been discharged on the first tray  35 , in the discharge direction, in other words, the trailing edge E 1  of the medium P, comes in contact with the upstream end matching members  38  and the position is matched thereto. When a plurality of mediums P are mounted on the first tray  35 , the trailing edges E 1  of the plurality of mediums P are matched with the upstream end matching members  38 . 
     Furthermore, the medium transporting apparatus  30  includes width direction matching members  45  that match the end portions of the mediums P in the width direction. As illustrated in  FIG.  7   , the width direction matching members  45  include a first matching portion  45   a  that is provided in a +X direction, serving as a first direction in the width direction, of the first tray  35 , and a second matching portion  45   b  provided in a −X direction, serving as a second direction opposite the first direction, of the first tray  35 . The width direction matching members  45  match the end portions of the mediums P in the width direction by, after the mediums P have been mounted between the first matching portion  45   a  and the second matching portion  45   b , having the first matching portion  45   a  and the second matching portion  45   b  move close to each other and come in contact with the end portions of the mediums P in the width direction. An operation of matching the mediums P in the width direction with the width direction matching members  45  will be described later. 
     Referring next to  FIGS.  5  and  6   , mounting of the medium P discharged from the pair of discharge rollers  33  to the first tray  35  will be described. 
     The leading edge E 2  of the medium P discharged from the pair of discharge rollers  33  lands on a mount surface  35   a  in the first tray  35  as illustrated in the upper drawing in  FIG.  5   . A landing position of the medium P differs according to the stiffness and the size of the medium P. A position G 2  in the upper drawing in  FIG.  5    illustrates a position on the mount surface  35   a  where the medium P lands when an leading edge E 2  of the medium P does not hang down. When the stiffness of the medium P is high, the medium P moves straight in the discharge direction and lands on the mount surface  35   a  at position G 2 . On the other hand, for example, the leading edges E 2  of plain paper and thin paper that has stiffness lower than that of plain paper hang down. Plain paper and thin paper land at a position upstream of position G 2  in the discharge direction such as a position indicated by reference numeral G 1  in the upper drawing in  FIG.  5   . 
     After the leading edge E 2  of the medium P has landed on the mount surface  35   a , the medium P proceeds on the mount surface  35   a  in the discharge direction until, as illustrated in the lower drawing in  FIG.  5   , the trailing edge E 1  becomes separated from the nip of the pair of discharge rollers  33 . 
     While the discharge of the medium P is performed by the pair of discharge rollers  33 , the guide members  41  are located at the retracted position as illustrated in the upper and lower drawings in  FIG.  5    so that the guide members  41  do not interrupt the discharge of the medium P performed by the pair of discharge rollers  33 . 
     When the trailing edge E 1  of the medium P is separated from the nip of the pair of discharge rollers  33 , as illustrated in the upper drawing in  FIG.  6   , the guide members  41  advance to the advanced position that is closer to the first tray  35  than the retracted position. The medium P falls on the mount surface  35   a  by its own weight and is reliably mounted on the mount surface  35   a  with the guide members  41  that have been displaced form the retracted position to the advanced position. With the above, the medium P discharged from the pair of discharge rollers  33  can be appropriately guided to the first tray  35 . 
     When the medium P is mounted on the mount surface  35   a , the paddles  40  rotate counterclockwise in  FIG.  6   . A hollow arrow in the lower diagram in  FIG.  6    depicts the rotation direction of the paddles  40 . 
     By having the paddles  40  in contact with the medium P rotate, the trailing edge E 1  of the medium P moves in a direction extending towards the upstream end matching member  38 , and the trailing edge E 1  is abutted against the upstream end matching member  38 . With the above, the position of the trailing edge E 1  of the medium P mounted on the first tray  35  is matched with the upstream end matching member  38 . 
     When the rotation shaft  40 A is in a stopped state, the paddles  40  are, as illustrated as an example in the upper drawing in  FIG.  5   , located at a position that does not interrupt the discharge of the medium P with the pair of discharge rollers  33  and, as illustrated in the lower drawing in  FIG.  6   , with the rotation of the rotation shaft  40 A, the paddles  40  come in contact with the medium P on the mount surface  35   a  and are rotated. In the present embodiment, the paddles  40  rotate a single turn for a single medium P and returns to and stops at the position illustrated in the upper drawing in  FIG.  5   . 
     Note that in the present embodiment, auxiliary paddles  44  that rotate about a rotation shaft  44 A are provided below the pair of discharge rollers  33 . The auxiliary paddles  44  are disposed closer to the upstream end matching members  38  than the paddles  40  and, same as the paddles  40 , rotate counterclockwise in the lower drawing in  FIG.  6   . By providing the auxiliary paddles  44 , the medium P can be abutted against and matched with the upstream end matching members  38  in a further reliable manner. 
     Furthermore, after rotating the paddles  40  and matching the trailing edge E 1  of the medium P against the upstream end matching members  38 , matching of the end portions of the medium P in the width direction is performed with the width direction matching members  45  (the first matching portion  45   a  and the second matching portion  45   b ). 
     The first matching portion  45   a  and the second matching portion  45   b  are configured to perform the matching operation that matches the end portions of the medium P in the width direction by moving from first positions X 1  illustrated in the upper drawing in  FIG.  13    that are positions outside the medium P, which is mounted on the first tray  35 , in the width direction to second positions X 2  illustrated in the middle drawing in  FIG.  13    that are positions inside the first positions X 1  in the width direction. Note that in  FIG.  13   , illustrations of a low frictional resistance member  50   a  provided in the first matching portion  45   a  and a low frictional resistance member  50   b  provided in the second matching portion  45   b  are omitted. 
     From when the discharge of the medium P from the pair of discharge rollers  33  is started until when the trailing edge E 1  of the medium P is matched with the upstream end matching members  38  with the rotation of the paddles  40 , the first matching portion  45   a  and the second matching portion  45   b  are, as illustrated in the upper drawing in  FIG.  13   , positioned at the first positions X 1  outside the medium P, which is mounted on the first tray  35 , in the width direction. The first positions X 1  are positions in which the gap between the first matching portion  45   a  and the second matching portion  45   b  are slightly larger than the width of the medium P, which is a length that can tolerate the position aberration of the medium in the width direction and match the medium. 
     After matching of the trailing edge E 1  of the medium P described above is performed, the first matching portion  45   a  and the second matching portion  45   b  move closer to each other and move to the second positions X 2 . The second positions X 2  are positions where the gap between the first matching portion  45   a  and the second matching portion  45   b  is substantially the same as the width of the medium P. 
     By performing the above matching operation, for example, even when there is a position aberration in the width direction between a first medium P 1  that has been discharged first and a second medium P 2  that has been discharged afterwards, as illustrated in the upper drawing in  FIG.  13   , the end portions of the first medium P 1  and the second medium P 2  in the width direction can be matched. 
     After the matching operation has ended, the first matching portion  45   a  and the second matching portion  45   b  return to the first positions X 1  illustrated in the lower drawing in  FIG.  13    and prepare for the discharge of the next medium. 
     When a plurality of mediums P are continuously mounted on the first tray  35 , after performing, on the first medium P 1  that is discharged first, the matching of the trailing edge E 1  using the paddles  40  and the matching of the end portions of both sides of the first medium P 1  in the width direction with the width direction matching members  45 , the guide members  41  are returned to the retracted position before the second medium P 2  is discharged from the pair of discharge rollers  33 . Note that it is desirable that the guide members  41  are at the advanced position until directly before the second medium P 2  is discharged from the pair of discharge rollers  33 . With the above, since the guide members  41  hold down the first medium P 1  mounted first on the first tray  35 , curling of the first medium P 1  can be suppressed. 
     The timing at which the guide members  41  are displaced between the retracted position and the advanced position, the timing at which the paddles  40  are rotated, and the timing at which the matching operation is performed with the width direction matching members  45  can be determined based on a detection of the medium P with a medium detection member  39  provided upstream of the pair of discharge rollers  33 . For example, each of the operations can be performed after a passage of a predetermined time from when the trailing edge E 1  of the medium P has been detected with the medium detection member  39 . 
     The processing portion  36 , which is provided near the upstream end matching members  38 , performs processes such as the stapling process on a single or a plurality of mediums P mounted on the first tray  35  after the trailing edges E 1  and both end portions in the width direction have been matched in the medium transporting apparatus  30 . The mediums P on which the process has been performed with the processing portion  36  are discharged from the first tray  35  to the second tray  37  with the upper rollers  42  and the lower rollers  43 . 
     Hereinafter, the guide members  41 , the width direction matching members  45 , and the paddles  40  will be described in detail. 
     Regarding Guide Members, Width Direction Matching Members, and Paddles 
     In the medium transporting apparatus  30  according to the present embodiment, the guide members  41  and the width direction matching members  45  are configured to move in the width direction in an interlocked manner. 
     Furthermore, in the present embodiment, the paddles  40  are also configured to move in the width direction while being interlocked with the movements of the guide members  41  and the width direction matching members  45 . 
     As illustrated in  FIG.  7   , the width direction matching members  45 , the guide members  41 , and the paddles  40  are provided on both sides with respect to the center C in the width direction, and are disposed from the outer side towards the center in the width direction in the order of the width direction matching members  45 , the guide members  41 , and the paddles  40 . 
     In other words, the guide member  41   a  and the guide member  41   b  are disposed inside the first matching portion  45   a  and the second matching portion  45   b , and the paddle  40   a  and the paddle  40   b  are disposed inside the guide member  41   a  and the guide member  41   b.    
     Furthermore, the width direction matching members  45 , the guide members  41 , and the paddles  40  are disposed at positions that do not overlap each other in plan view Accordingly, the width direction matching members  45 , the guide members  41 , and the paddles  40  can be prevented from interfering each other in the height direction. 
     In  FIG.  7   , the first matching portion  45   a  and the second matching portion  45   b  depicted by solid lines illustrate a state in which the first matching portion  45   a  and the second matching portion  45   b  are positioned on the outermost side in the width direction, and the guide members  41   a  and  41   b  are disposed right inside the first matching portion  45   a  and the second matching portion  45   b , and the paddles  40   a  and  40   b  are disposed further inside. In  FIG.  7   , the first matching portion  45   a  and the second matching portion  45   b  depicted by dot and dash lines illustrates a state in which the first matching portion  45   a  and the second matching portion  45   b  are positioned on the innermost side in the width direction. In the above state, the guide member  41   a  and the paddle  40   a  move inward while maintaining relative positional relationships with the first matching portion  45   a , and the guide member  41   b  and the paddle  40   b  (see  FIG.  15    as well) move inward while maintaining relative positional relationships with the second matching portion  45   b . It goes without saying that the guide member  41   a  and the paddle  40   a  can be moved while the relative positional relationship between the first matching portion  45   a  and the guide member  41   a  or the paddle  40   a  changes. Note that  FIG.  15    illustrates the second matching portion  45   b  on the −X side positioned on the innermost side in the width direction. 
     Note that the medium transporting apparatus  30  of the present embodiment is configured to transport mediums P of a plurality of sizes. 
     As in the present embodiment, when the guide members  41  and paddles  40  are provided on both sides with respect to the center C in the width direction as pairs, it is desirable that the guide members  41   a  and  41   b  and the paddles  40   a  and  40   b  are disposed close to the end portions on both sides of the medium P in the width direction. When the guide members  41   a  and  41   b  are disposed close to the end portions on both sides of the medium P in the width direction, curling of the medium P mounted on the first tray  35  can be suitably suppressed. Furthermore, it is desirable that the paddles  40   a  and  40   b  are disposed close to the end portions on both sides of the medium P in the width direction since skewing does not easily occur when the medium P moves towards the upstream end matching members  38 . 
     By configuring the guide members  41 , the paddles  40 , and the width direction matching members  45  to move in an interlocked manner, the guide members  41  and the paddles  40  can be moved while being interlocked with the movements of the width direction matching members  45  corresponding to the size of the medium P; accordingly, the medium P can be disposed at a position suitable for its size. Furthermore, since the pair of guide members  41 , the pair of paddles  40 , and the pair of width direction matching members  45  can be made to correspond to a plurality of sizes of mediums P, compared with providing the guide members and paddles having fixed positions, an increase in the number of parts can be suppressed and the increase in cost or increase in the size of the apparatus due to the increase in the number of parts can be avoided. 
     Furthermore, by disposing the width direction matching members  45 , the guide members  41 , and the paddles  40  in that order from the outside in the width direction of the medium P, the matching of the end portion of the medium P in the width direction with the width direction matching members  45 , the guiding of the medium P with the guide members  41 , and the moving of the medium P towards the upstream end matching members  38  with the paddles  40  can each be performed appropriately. Furthermore, by disposing the paddles  40  inside the guide members  41 , the medium P can be moved with the paddles  40  while reliably suppressing curling of the end portions of the medium P in the width direction. 
     Furthermore, low frictional resistance members  50  are provided in the medium transporting apparatus  30 . A detailed description of the low frictional resistance members  50  will be given below. 
     Regarding Low Frictional Resistance Members 
     The low frictional resistance members  50  are configured to switch between an advanced state, as illustrated in  FIG.  9   , advanced from outside a medium mount region K of the first tray  35  to first regions M including the positions in the medium mount region K where the paddles  40  are in contact with the medium P (see also the lower drawing in  FIG.  6   ), and a retracted state, as illustrated in  FIG.  10   , retracted from the first regions M to the outside of the medium mount region K. In the present embodiment, the low frictional resistance members  50  are provided at both end portions in the width direction and are configured of the low frictional resistance member  50   a  on the +X side and the low frictional resistance member  50   b  on the −X side. 
     The low frictional resistance members  50  are components in which the frictional coefficient between the low frictional resistance member  50  and the medium P is lower than the frictional coefficient between the mediums P. 
     In the present embodiment, the low frictional resistance members  50  are each formed in a sheet shape. A resin sheet that can be curved such as, for example, a polyethylene terephthalate (PET) sheet can be used as the sheet-shaped low frictional resistance member  50 . 
     As illustrated in  FIG.  9   , the low frictional resistance members  50  are fixed to rotation shafts  51  disposed outside the medium mount region K and are switched between the advanced state illustrated in  FIGS.  9  and  11    and the retracted state illustrated in  FIG.  10    by rotating the rotation shafts  51  as illustrated in  FIG.  14   . With such a configuration, switching of the low frictional resistance members  50  between the advanced state and the retracted state can be achieved with a simple configuration. A mount configuration of the low frictional resistance member  50  will be specifically described below. 
     In the lower diagram in  FIG.  14    illustrating an example of the advanced state, the sheet-shaped low frictional resistance members  50  are disposed with a shape in which the low frictional resistance members  50  extended towards the outside of the medium mount region K from fixed ends F 1  fixed to the rotation shafts  51  are curved and free end F 2  sides are advanced to the first regions M. 
     By having the low frictional resistance members  50  be brought to the advanced state while the sheet-shaped low frictional resistance member  50  are in a curved state, the low frictional resistance members  50  can be configured so that the free end F 2  sides are elastically advanced to the first regions M. Accordingly, curling and lifting up of the medium P mounted under the low frictional resistance members  50  can be suppressed more reliably. 
     As illustrated in  FIG.  9   , in the present embodiment, the first regions M are disposed in the end portions on both sides of the medium mount region K in the width direction. In other words, the low frictional resistance members  50   a  and  50   b  in the advanced state are disposed on the end portions on both sides of the medium mount region K in the width direction. Since the low frictional resistance members  50   a  and  50   b  in the advanced state hold down both end portions of the medium P, which has been discharged to the first tray  35 , in the width direction, curling of the medium P in the width direction can be suppressed effectively. Furthermore, components that switch the low frictional resistance members  50   a  and  50   b  between the advanced state and the retracted state are disposed easily. 
     The rotation shafts  51  to which the low frictional resistance members  50  are attached are, as illustrated in  FIG.  8   , disposed in a direction extending in the discharge direction. Furthermore, the rotation shafts  51   a  and  51   b  are attached to the first matching portion  45   a  and the second matching portion  45   b . As illustrated in  FIG.  9   , the rotation shaft  51   a  of the low frictional resistance member  50   a  is fixed to the first matching portion  45   a , and the rotation shaft  51   b  of the low frictional resistance member  50   b  is fixed to the second matching portion  45   b . As illustrated in  FIG.  8   , the fixed end F 1  of the low frictional resistance member  50   b  is fixed to the rotation shaft  51   b  with fixing members  59   b  such as screws or the like. Similar to the low frictional resistance member  50   b , the first matching portion  45   a  is fixed to the rotation shaft  51   a  with fixing members  59   a  ( FIG.  7   ). 
     The first matching portion  45   a  and the second matching portion  45   b  are configured to move to positions corresponding to the width size of the medium P. As illustrated in  FIG.  10   , the first matching portion  45   a  and the second matching portion  45   b  are provided on base portions  47   a  and  47   b  configured to move in the width direction by being guided by guide grooves  46   a  and  46   b  provided so as to extend in the width direction. The first matching portion  45   a  and the second matching portion  45   b  are moved by receiving motive power from a first motor  61   a  and a second motor  61   b  described later. 
     In the above, since the rotation shafts  51   a  and  51   b  are attached to the first matching portion  45   a  and the second matching portion  45   b  that move according to the size of the medium P in the width direction, the low frictional resistance members  50   a  and  50   b  can be made to move by following the movement of the first matching portion  45   a  and the second matching portion  45   b . With the above, the low frictional resistance members  50   a  and  50   b  can be disposed at the end portions of the medium P in the width direction. 
     The switching of the low frictional resistance members  50  between the retracted state and the advanced state performed by rotating the rotation shafts  51  will be described next. 
     The retracted state of the low frictional resistance members  50  are illustrated in the upper drawing in  FIG.  14   . In the above state, the phase of the rotation shafts  51  is denoted as α 0 . In bringing the low frictional resistance members  50  to the advanced state, the rotation shaft  51   a  of the low frictional resistance member  50   a  located on the +X side is rotated clockwise in  FIG.  14   , and the rotation shaft  51   b  of the low frictional resistance member  50   b  located on the −X side is rotated counterclockwise. 
     The upper drawing and the middle drawing in  FIG.  14    both depict the advanced state of the low frictional resistance members  50 . The phases of the rotation shafts  51   a  and  51   b  are different between the middle drawing and the lower drawing in  FIG.  14   . In the middle drawing in  FIG.  14   , the phases of the rotation shafts  51   a  and  51   b  are in a state of phase α 1  that is, in the rotation direction, close to phase α 0  that is a phase when in the retracted state illustrated in the upper drawing in  FIG.  14   . In the lower drawing in  FIG.  14   , the phases of the rotation shafts  51   a  and  51   b  are in a state of phase α 2  that is farther away from phase α 0  (the upper drawing in  FIG.  14   ) than phase α 1  (the middle drawing in  FIG.  14   ) in the rotation direction. 
     Curvatures of the curves of the low frictional resistance members  50   a  and  50   b  when the phases of the rotation shafts  51   a  and  51   b  are phase α 2  (the lower drawing in  FIG.  14   ) are larger than curvatures of the curves of the low frictional resistance members  50   a  and  50   b  when the phases of the rotation shafts  51   a  and  51   b  are phase α 1  (the middle drawing in  FIG.  14   ); accordingly, due to the elasticities of the curves, the pressing force of the free ends F 2  of the low frictional resistance members  50  in the first regions M is larger in the state illustrated in the lower drawing in  FIG.  14    than the state illustrated in the middle drawing in  FIG.  14   . By changing the rotation phases of the rotation shafts  51   a  and  51   b  in the advanced state, the pressing force applied to the first regions M with the free ends F 2  of the low frictional resistance members  50  can be changed. 
     The rotation phases of the rotation shafts  51   a  and  51   b  in the advanced state can be controlled with a control unit  60  ( FIG.  12   ) provided in the processing unit  4 . The control unit  60  controls the rotations of the rotation shafts  51   a  and  51   b  by controlling a sheet motor  52  that is a drive source that rotates the rotation shafts  51   a  and  51   b . Note that the control of the rotation shafts  51   a  and  51   b  can be performed with, for example, the control unit  15  that is provided in the recording unit  2  illustrated in  FIG.  1    and that controls the recording system  1 . A configuration that transmits the motive power from the sheet motor  52  to the rotation shafts  51   a  and  51   b  will be described later. 
     Timings at which the retracted state ( FIG.  10   ) and the advanced state ( FIG.  11   ) of the low frictional resistance members  50  are switched will be described next. 
     In the present embodiment, the low frictional resistance members  50  are switched to the advanced state ( FIG.  11   ) from the retracted state ( FIG.  10   ) after the first medium P 1  has been mounted on the first tray  35  and after the trailing edge E 1  and both end portions in the width direction have been matched. Accordingly, the second medium P 2  that is discharged subsequent to the first medium P 1  from the pair of discharge rollers  33  is, as illustrated in  FIG.  11   , discharged on the low frictional resistance members  50  that is in the advanced state and that is on the first medium P 1 . 
     In other words, when the second medium P 2  discharged from the pair of discharge rollers  33  after the first medium P 1  had been discharged is moved towards the upstream end matching members  38  with the paddles  40 , the low frictional resistance members  50  are interposed between the first medium P 1  and the second medium P 2 . 
     By interposing the low frictional resistance members  50  between the first medium P 1  and the second medium P 2 , when moving the second medium P 2  towards the upstream end matching members  38  with the paddles  40 , the frictional resistance between the first medium P 1  and the second medium P 2  is reduced and it will be easier to move the second medium P 2  with the paddles  40 . Accordingly, it will be possible to abut the second medium P 2  against the upstream end matching members  38  in a more reliable manner, and matching of the end portion of the medium can be performed appropriately. 
     When the frictional resistance between the first medium P 1  and the mount surface  35   a  of the first tray  35  is smaller than the frictional resistance between the mediums P, the low frictional resistance members  50  may be in the retracted state when the first medium P 1  is mounted as the first sheet on the first tray  35 . Note that the first tray  35  can be formed of resin, metal, or the like. 
     Furthermore, after the second medium P 2  has been moved with the paddles  40 , the low frictional resistance members  50  are temporarily switched from the advanced state to the retracted state and, then, are switched to the advanced state positioned above the second medium P 2 . In the present embodiment, after the second medium P 2  is moved with the paddles  40  and before the matching operation is performed on the second medium P 2  with the width direction matching members  45 , the low frictional resistance members  50  are temporarily switched from the advanced state to the retracted state and, then, are switched to the advanced state positioned above the second medium P 2 . 
     Since the low frictional resistance members  50  are disposed on the second medium P 2  after the trailing edge E 1  of the second medium P 2  has been matched, curling and lifting up of the second medium P 2  can be suppressed. 
     Particularly, when the end portions of the medium P in the width direction are curled when the matching operation is performed with the width direction matching members  45  (the first matching portion  45   a  and the second matching portion  45   b ), the matching of the medium P in the width direction may become insufficient. In the present embodiment, since the low frictional resistance members  50  are switched to the advanced state positioned above the second medium P 2  before the matching operation in the width direction is performed on the second medium P 2  with the width direction matching members  45 , when the matching operation is performed with the width direction matching members  45 , curling of the second medium P 2  is held down and matching in the width direction can be performed appropriately. 
     Furthermore, as illustrated in the upper drawing in  FIG.  5   , the first regions M according to the present embodiment each include the position where the leading edge E 2  of the second medium P 2  in the discharge direction first comes in contact with the first medium P 1  when the second medium P 2  is discharged from the pair of discharge rollers  33 . In the upper drawing in  FIG.  5   , the positions G 1  and G 2  that are examples of the landing position of the second medium P 2  on the first tray  35  are included in the first region M. Note that while the reference signs G 1  and G 2  depicted in the upper drawing in  FIG.  5    are the landing positions of the first medium P 1 , when the first medium P 1  and the second medium P 2  are of the same type, the landing positions of the second medium P 2  discharged subsequent to the first medium P 1  are substantially the same as that of the first medium P 1 ; accordingly, it is assumed that the reference signs G 1  and G 2  are the landing positions of the second medium P 2 . 
     The position G 2  is the landing position when the stiffness of the medium P is high and the medium P moves straight in the discharge direction without hanging down. The position G 1  indicates the landing position of the medium P having a stiffness lower than the above. 
     When the second medium P 2  is discharged on the first medium P 1 , after the leading edge E 2  of the second medium P 2  in the discharge direction has landed on the first medium P 1 , the second medium P 2  moves in the discharge direction on the first medium P 1  until the trailing edge E 1  in the discharge direction is separated from the pair of discharge rollers  33 . 
     Note that when the frictional resistance between the first medium P 1  and the second medium P 2  is large, moving of the leading edge E 2  of the second medium P 2 , which has landed on the first medium P 1 , in the discharge direction may be hindered by the frictional resistance between the mediums and there are cases in which the second medium P 2  is not appropriately mounted on the first tray  35 . 
     By having the landing position (for example, the position G 1  or the position G 2 ) of the leading edge E 2  of the second medium P 2  be included in the first regions M, the second medium P 2  can, after the leading edge E 2  has landed, move on the low frictional resistance members  50  in the discharge direction. Since the frictional resistance between the low frictional resistance members  50  and the second medium P 2  is lower than the frictional resistance between the first medium P 1  and the second medium P 2 , incidents such as the leading edge E 2  of the second medium P 2  that has landed becoming caught can be reduced; accordingly, the second medium P 2  can be appropriately mounted on the first tray  35 . 
     Furthermore, the rotation phases of the rotation shafts  51  can be controlled according to the number of mediums P mounted on the first tray  35 . The rotation phases of the rotation shafts  51  are, as described above, controlled by the control unit  60 . 
     When the number of mediums P on the first tray  35  increases, the position of the uppermost medium P becomes high. As in the present embodiment, when the sheet-shaped low frictional resistance members  50  are brought to the advanced state by being curved, if the mediums P are mounted on the first tray  35  while the rotation phases of the rotation shafts  51  are fixed to α 2  illustrated in the lower drawing in  FIG.  14   , the free ends F 2  of the low frictional resistance members  50  are pushed up and the curvatures of the curves become larger as the number of the mounted sheets increases. Accordingly, the pressing force applied to the mediums P by the low frictional resistance members  50  becomes large. When the pressing force applied to the mediums P by the low frictional resistance members  50  becomes large, there are cases in which the uppermost medium P with which the low frictional resistance members  50  are in contact becomes damaged. Furthermore, when the curvatures of the curves of the low frictional resistance members  50  become large due to the increase in the number of mounted sheets, the free ends F 2  of the low frictional resistance members  50  become oriented upwards and the adhesion between the low frictional resistance members  50  and the uppermost medium P decreases. If the low frictional resistance members  50  and the uppermost medium P are not in surface contact with each other, the medium subsequently mounted may become caught. Furthermore, if a state in which the low frictional resistance members  50  are curved with large curvatures continue, the low frictional resistance members  50  may develop a tendency of being curved. 
     In the present embodiment, the control unit  60  can control the rotation phases of the rotation shafts  51  so that pressing force from the low frictional resistance members  50  is reduced in accordance with the increase in the number of mounted mediums P. For example, by changing the state illustrated in the lower drawing in  FIG.  14    in which the phases of the rotation shafts  51  are α 2  to the state illustrated in the middle drawing in  FIG.  14    in which the phases are α 1 , which is smaller than the curvatures of the curves of the low frictional resistance members  50  in the lower drawing in  FIG.  14   , the pressing force of the low frictional resistance members  50  that has increased due to the increase in the number of mounted mediums P can be reduced. With the above, regardless of the number of mounted mediums P, the change in the pressing force applied to the mediums P with the low frictional resistance members  50  in the advanced state can be made small. 
     Furthermore, the free ends F 2  of the low frictional resistance members  50  can be prevented from being oriented upwards as the number of mounted mediums P increases, and the low frictional resistance members  50  and the uppermost medium P can be adhered to each other. Accordingly, the subsequent medium P can be prevented from being caught by the low frictional resistance members  50 . Furthermore, the possibility of the low frictional resistance members  50  developing a tendency to become curved can be reduced. 
     Referring next to  FIG.  12   , a drive mechanism of the low frictional resistance members  50   a  and  50   b  that are switched between the advanced state and the retracted state, and a moving mechanism of the width direction matching members  45  (the first matching portion  45   a  and the second matching portion  45   b ) that move in the width direction will be described. 
     Regarding Drive Mechanism of Low Frictional Resistance Members 
     The advanced state and the retracted state of the low frictional resistance members  50   a  and  50   b  are switched by rotating the rotation shafts  51   a  and  51   b  with the motive power of the sheet motor  52 . The rotation of the sheet motor  52  is transmitted to a first shaft portion  57  through a gear  53  serving as a motive power transmission mechanism. The first shaft portion  57  is provided so as to extend in the X-axis direction that is the width direction, and a lower pulley  54   a  is provided on the +X side and a lower pulley  54   b  is provided on the −X side. The lower pulley  54   a  and the lower pulley  54   b  rotate about the first shaft portion  57 . An upper pulley  55   a  and an upper pulley  55   b  are provided above the lower pulley  54   a  and the lower pulley  54   b , respectively. An endless belt  56   a  is stretched around the lower pulley  54   a  and the upper pulley  55   a , and an endless belt  56   b  is stretched around the lower pulley  54   b  and the upper pulley  55   b . The rotations of the lower pulleys  54   a  and  54   b  are transmitted to the upper pulleys  55   a  and  55   b  through the endless belts  56   a  and  56   b . Furthermore, the rotations are transmitted from the upper pulleys  55   a  and  55   b  to the rotation shafts  51   a  and  51   b  through crossed helical gears  65   a  and  65   b.    
     A phase detection member  58  that detects the rotation phase of the first shaft portion  57  is provided in an end portion of the first shaft portion  57  on the −X side. Information on the phases of the rotation shafts  51   a  and  51   b  can be obtained based on the detection result of the phase detection member  58 . 
     The control unit  60  controls the drive of the sheet motor  52  based on the detection result of the medium P with the medium detection member  39  illustrated in  FIG.  2    and on information on the phases of the rotation shafts  51   a  and  51   b  based on the detection result of the phase detection member  58 . With the above, the control of the timing at which the advanced state and the retracted state of the low frictional resistance members  50   a  and  50   b  are switched, and the control of the pressing force of the low frictional resistance members  50   a  and  50   b  in the advanced state performed by controlling the phases of the rotation shafts  51   a  and  51   b  can be performed. 
     Regarding Moving Mechanism of Width Direction Matching Members 
     In the present embodiment, the first matching portion  45   a  and the second matching portion  45   b  are driven by discrete drive sources. The first matching portion  45   a  is driven by the first motor  61   a , and the second matching portion  45   b  is driven by the second motor  61   b . The first motor  61   a  and the second motor  61   b  are each disposed at a position near the center in the width direction. 
     The moving mechanism of the first matching portion  45   a  includes a driving pulley  62   a  that rotates by receiving motive power from the first motor  61   a , a driven pulley  63   a  provided away from the driving pulley  62   a  in the +X direction, and an endless belt  64   a  stretched around the driving pulley  62   a  and the driven pulley  63   a . The first matching portion  45   a  is attached to the endless belt  64   a  through an attaching portion  48   a . The first motor  61   a  is configured to rotate both in a positive rotation direction and a reverse rotation direction. The moving direction of the endless belt  64   a  can be switched by changing the rotation direction of the first motor  61   a . With such a configuration, the first matching portion  45   a  can be moved in the X-axis direction. 
     The moving mechanism of the second matching portion  45   b  includes a driving pulley  62   b , a driven pulley  63   b , an endless belt  64   b , and an attaching portion  48   b  that correspond to the driving pulley  62   a , the driven pulley  63   a , the endless belt  64   a , and the attaching portion  48   a  of the moving mechanism of the first matching portion  45   a . The configuration thereof is similar to that of the first matching portion  45   a ; accordingly, a detailed description thereof is omitted. 
     In the present embodiment, while the first matching portion  45   a  and the second matching portion  45   b  are driven by different drive sources, the first matching portion  45   a  and the second matching portion  45   b  can both be moved by a belt mechanism driven by a single drive source. Furthermore, instead of the belt mechanism, for example, a rack and pinion mechanism may be used. 
     Furthermore, similar to the moving mechanism of the width direction matching members  45  described above with reference to  FIG.  12   , the moving mechanism that moves the guide members  41  (the guide members  41   a  and  41   b ) and the paddles  40  (the paddles  40   a  and  40   b ) in the width direction can be a belt mechanism including an endless belt stretched around pulleys, or can be a rack and pinion mechanism. 
     The width direction matching members  45 , the guide members  41 , and the paddles  40  can be operated with discrete drive sources. Alternatively, the width direction matching members  45 , the guide members  41 , and the paddles  40  can be operated with common drive sources. For example, the first matching portion  45   a , the guide member  41   a , and the paddle  40   a  can be operated with the motive power from the first motor  61   a , and the second matching portion  45   b , the guide member  41   b , and the paddle  40   b  can be operated with the second motor  61   b.    
     Furthermore, as illustrated in  FIG.  16   , the guide member  41   b  and the paddle  40   b  can be fixed to the second matching portion  45   b  that moves in the width direction with the moving mechanism illustrated in  FIG.  12    so that the guide member  41   b  and the paddle  40   b , following the movement of the second matching portion  45   b , are moved. 
     The second matching portion  45   b  includes a first coupling portion  72  and a second coupling portion  73 . The first coupling portion  72  is coupled to a first coupled portion  71  of the guide member  41   b . The second coupling portion  73  is coupled to the second coupled portion  74  of the paddle  40   b . The first coupled portion  71  of the guide member  41   b  is attached to the pivot shaft  41 A in a slidable manner. The second coupled portion  74  of the paddle  40   b  is attached to the rotation shaft  40 A in a slidable manner. 
     With the above configuration, when the second matching portion  45   b  moves in the width direction, the guide member  41   b  and the paddle  40   b  can be moved integrally with the second matching portion  45   b.    
     The first matching portion  45   a , the guide member  41   a , and the paddle  40   a  on the +X side, illustration of which is omitted in  FIG.  16   , can be configured in a similar manner to that of the second matching portion  45   b , the guide member  41   b , and the paddle  40   b  illustrated in  FIG.  16   . 
     In the above configuration, the guide members  41  and the paddles  40  can also be moved with the motive power of the first motor  61   a  and the second motor  61   b  that are drive sources of the width direction matching members  45 . 
     Furthermore, the guide members  41  and the paddles  40  are configured to be switched to a state that is not interlocked with the movements of the width direction matching members  45  when the width direction matching members  45  perform the matching operation described with reference to  FIG.  13   . 
     The guide members  41  and the paddles  40  do not need to be moved in the width direction when the width direction matching members  45  perform the matching operation. If the guide members  41  and the paddles  40  are made to follow the movements of the width direction matching members  45  when the matching operation is performed, a large sound may be generated with the movement of the guide members  41  and the paddles  40 . By switching to a state in which the guide members  41  and the paddles  40  are not interlocked with the movement of the width direction matching members  45 , the operation sound while performing the matching operation can be reduced when the width direction matching members  45  perform the matching operation. 
     If the movements of the width direction matching members  45 , the guide members  41 , and the paddles  40  can be controlled independently, switching between interlocking and not interlocking the guide members  41  and the paddles  40  with the movements of the width direction matching members  45  can be performed easily. 
     Furthermore, in a configuration illustrated in  FIG.  16    in which the guide members  41  and the paddles  40  are integrally coupled to and move with the width direction matching members  45 , for example, a clearance space in the width direction can be provided between the first coupling portion  72  and the first coupled portion  71  and between the second coupling portion  73  and the second coupled portion  74  so that when the width direction matching members  45  have moved a predetermined distance or more in the width direction, the guide members  41  and the paddles  40  are coupled to the width direction matching members  45  so that the guide members  41  and the paddles  40  can move integrally with the width direction matching members  45 . 
     Note that in the present embodiment, processing unit  4  can be comprehended as a “medium processing apparatus” that includes the medium transporting apparatus  30  and the processing portion  36  that performs a predetermined process on the medium mounted on the first tray  35 . Furthermore, the recording system  1  can be comprehended a “medium processing apparatus” that includes the medium transporting apparatus  30  and the processing portion  36  that performs a predetermined process on the medium mounted on the first tray  35 . Furthermore, an apparatus in which the recording function has been omitted from the recording system  1  can be comprehended as a “medium transporting apparatus”. Alternatively, even provided with a recording function, when focusing on the viewpoint of medium transportation, the recording system  1  itself can be regarded as a medium transporting apparatus. 
     Furthermore, the low frictional resistance members  50  can be configured so that the low frictional resistance members  50  are switched between the advanced state and the retracted state by being moved in a linear manner, for example. 
     Note that not limited to the embodiments described above, various modifications that are within the scope of the claims can be made. It goes without saying that the modifications are also included in the scope of the disclosure.