Patent Publication Number: US-11046546-B2

Title: Medium discharge device and recording apparatus

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The entire disclosure of Japanese Patent Application Nos. 2018-13829, filed Jan. 30, 2018 and 2018-198207, filed Oct. 22, 2018 are expressly incorporated by reference herein. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a medium discharge device that discharges a medium and a recording apparatus including the medium discharge device. 
     2. Related Art 
     In a recording apparatus represented by a printer or the like, a sorter that sorts discharged sheets of paper is installed, in some cases. The sorter may include a plurality of bins disposed in an up-down direction and a sheet transport unit that receives the sheet discharged from the recording apparatus and sends the sheet to any bin. Sorting of the sheets to any bin is performed by a bin fixed type, in which the sheet transport unit moves upward and downward so as to discharge the sheet to any bin, and a bin moving type, in which a position of the sheet transport unit is fixed, and a plurality of bins move upward and downward so as to accommodate the sheet. International Publication No. 2008/032482 discloses an example of the latter type. 
     When the sorter as described above is included in any types, that is, both the type in which the sheet transport unit moves upward and downward and the type in which the plurality of bins move upward and downward, a configuration of the apparatus increases, and thus the apparatus is likely to increase in size and costs. 
     SUMMARY 
     According to an aspect of the disclosure, a medium discharge device includes: a discharge unit that discharges a medium; a first medium receiving tray that receives the discharged medium; and a second medium receiving tray that is provided above the first medium receiving tray in a vertical direction and receives the discharged medium. The second medium receiving tray is capable of changing a position between an advance position for receiving a medium, which is discharged, by causing at least an upstream zone of the tray including an upstream side end portion in a medium discharge direction to traverse a passing route of the medium from the discharge unit toward the first medium receiving tray and a retraction position to which the upstream zone retracts from the passing route. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a perspective view illustrating the external appearance of a printer according to a first embodiment. 
         FIG. 2  is a sectional side view illustrating a medium transport route in the printer according to the first embodiment. 
         FIG. 3  is a sectional side view illustrating a state in which a medium is discharged to a first medium receiving tray in the first embodiment. 
         FIG. 4  is a sectional side view illustrating a state in which a medium is discharged to a second medium receiving tray in the first embodiment. 
         FIG. 5  is a perspective view illustrating a state of the second medium receiving tray at a retraction position. 
         FIG. 6  is a perspective view illustrating a state of the second medium receiving tray at an advance position. 
         FIG. 7  is a sectional side view illustrating the retraction position of the second medium receiving tray. 
         FIG. 8  is a sectional side view illustrating a state in which a position of the second medium receiving tray is switched from the retraction position to the advance position. 
         FIG. 9  is a sectional side view illustrating the advance position of the second medium receiving tray. 
         FIG. 10  is a sectional side view illustrating a relationship between the second medium receiving tray and a discharge roller pair at the advance position. 
         FIG. 11  is a sectional side view illustrating a discharge state to a first medium receiving tray according to a second embodiment. 
         FIG. 12  is a sectional side view illustrating a discharge state to a second medium receiving tray according to the second embodiment. 
         FIG. 13  is a sectional side view illustrating a discharge state to a third medium receiving tray according to the second embodiment. 
         FIG. 14  is a sectional side view illustrating a discharge state to a first medium receiving tray according to a third embodiment. 
         FIG. 15  is a sectional side view illustrating a discharge state to a second medium receiving tray according to the third embodiment. 
         FIG. 16  is a sectional side view illustrating a discharge state to a third medium receiving tray according to the third embodiment. 
         FIG. 17  is a sectional side view of a medium transport route for illustrating disposition of a detection lever. 
         FIG. 18  is a sectional side view of the medium transport route in a case of including a holding member. 
         FIG. 19  is a sectional side view of the medium transport route in a case of including a shutter. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, the disclosure will be schematically described. 
     According to a first aspect, there is provided a medium discharge device including: a discharge unit that discharges a medium; a first medium receiving tray that receives the medium discharged by the discharge unit; and a second medium receiving tray that is provided above the first medium receiving tray in a vertical direction and receives the medium discharged by the discharge unit. The second medium receiving tray is capable of changing a position between an advance position for receiving a medium, which is discharged, by causing at least an upstream zone of the tray including an upstream side end portion in a medium discharge direction to advance to a passing route of the medium from the discharge unit toward the first medium receiving tray and a retraction position to which the upstream zone retracts from the passing route. 
     According to the aspect, in a configuration in which the first medium receiving tray and the second medium receiving tray are provided, at least the upstream zone of the second medium receiving tray changes a position, and thereby it is possible to switch a discharge destination of the medium. In other words, since there is no need to employ a configuration in which all of the trays including the first medium receiving tray and the second medium receiving tray move upward and downward, and there is no need to employ a configuration in which the discharge unit moves upward and downward, it is possible to provide the medium discharge device that is capable of sorting media to be discharged, in a simpler configuration, in a small size, and at low costs. 
     In a second aspect according to the first aspect, the second medium receiving tray is configured to have a downstream zone that is provided to be fixed on a downstream side of the advanceable/retractable upstream zone in the medium discharge direction. 
     According to the aspect, the second medium receiving tray is configured to have the downstream zone that is provided to be fixed on the downstream side of the advanceable/retractable upstream zone in the medium discharge direction, that is, there is no need for the entire second medium receiving tray to perform a position changing operation, and thus it is possible to avoid an increase in configuration of the apparatus. 
     In a third aspect according to the second aspect, when the upstream zone of the second medium receiving tray is positioned at the advance position, a medium support surface provided in the upstream zone and a medium support surface provided in the downstream zone are both inclined upward in the same degree with respect to a horizontal toward the medium discharge direction. 
     According to the aspect, when the upstream zone of the second medium receiving tray is positioned at the advance position, the medium support surface provided in the upstream zone and the medium support surface provided in the downstream zone are both inclined upward in the same degree with respect to the horizontal toward the medium discharge direction, and thus it is possible to appropriately stack media to be discharged, in a natural shape. 
     In a fourth aspect according to any one of the first to third aspects, the discharge unit is configured of a discharge roller pair that nips and discharges the medium. When the upstream zone of the second medium receiving tray is positioned at the advance position, the upstream zone intersects a tangential line at a nip position of the discharge roller pair. 
     According to the aspect, the discharge unit is configured of the discharge roller pair that nips and discharges the medium. When the upstream zone of the second medium receiving tray is positioned at the advance position, the upstream zone intersects the tangential line at the nip position of the discharge roller pair. Therefore, it is possible to more reliably stack the media to be discharged from the discharge roller pair in the second medium receiving tray. 
     In a fifth aspect according to any one of the first to third aspects, the discharge unit is configured of a discharge roller pair that nips and discharges the medium. When the upstream zone of the second medium receiving tray is positioned at the advance position, the upstream side end portion is positioned below a nip position of the discharge roller pair in the vertical direction. 
     According to the aspect, the discharge unit is configured of the discharge roller pair that nips and discharges the medium. When the upstream zone of the second medium receiving tray is positioned at the advance position, the upstream side end portion is positioned below the nip position of the discharge roller pair in the vertical direction. Therefore, it is possible to more reliably stack the media to be discharged from the discharge roller pair in the second medium receiving tray. 
     In a sixth aspect according to any one of the first to fifth aspects, a position of the upstream side end portion of the upstream zone in the medium discharge direction is on a more upstream side in the medium discharge direction in a case where the upstream zone is positioned at the advance position than in a case where the upstream zone is positioned at the retraction position. 
     According to the aspect, the position of the upstream side end portion of the upstream zone in the medium discharge direction is on the more upstream side in the medium discharge direction in the case where the upstream zone is positioned at the advance position than in the case where the upstream zone is positioned at the retraction position, and thus it is possible to more reliably place the medium to be discharged. 
     In a seventh aspect according to any one of the first to sixth aspects, a medium support surface provided in the upstream zone of the second medium receiving tray is formed into an upward inclined surface toward the medium discharge direction with respect to a horizontal, and an inclination angle of the inclined surface with respect to the horizontal is larger in a case where the upstream zone is positioned at the advance position than in a case where the upstream zone is positioned at the retraction position. 
     According to the aspect, the medium support surface provided in the upstream zone of the second medium receiving tray is formed into the upward inclined surface toward the medium discharge direction with respect to the horizontal, and the inclination angle of the inclined surface with respect to the horizontal is larger in the case where the upstream zone is positioned at the advance position than in the case where the upstream zone is positioned at the retraction position. Therefore, it is possible to secure a wide space below the upstream zone in the case where the upstream zone is positioned at the retraction position, and thus it is possible to suppress interference of the upstream zone with the discharge of the medium to the first medium receiving tray. 
     In an eighth aspect according to any one of the first to seventh aspects, when the upstream zone of the second medium receiving tray is positioned at the advance position, a medium support surface provided in the second medium receiving tray and a medium support surface provided in the first medium receiving tray are both inclined upward in the same degree toward the medium discharge direction. 
     According to the aspect, when the upstream zone of the second medium receiving tray is positioned at the advance position, the medium support surface provided in the second medium receiving tray and the medium support surface provided in the first medium receiving tray are both inclined upward in the same degree toward the medium discharge direction. In this configuration, it is possible to achieve any operation effects of the first to seventh aspects described above. 
     In a ninth aspect according to any one of the first to eighth aspects, the upstream side end portion of the second medium receiving tray is provided with a regulatory wall that regulates a position of an upstream side end portion of a discharged medium. 
     According to the aspect, the upstream side end portion of the second medium receiving tray is provided with the regulatory wall that regulates the position of the upstream side end portion of the discharged medium, and thus it is possible to suppress sliding-down of the medium from the second medium receiving tray. 
     In a tenth aspect according to any one of the first to ninth aspects, a plurality of the second medium receiving trays are provided. 
     According to the aspect, in the configuration in which the plurality of second medium receiving trays are provided, it is possible to achieve operation effects of the first to tenth aspects described above. 
     In an eleventh aspect according to any one of the first to seventh aspects and the ninth and tenth aspects, the first medium receiving tray and the second medium receiving tray are disposed radially toward a downstream side in a discharge direction, in a side view of the passing route. 
     According to the aspect, since the first medium receiving tray and the second medium receiving trays are disposed radially toward the downstream side in the discharge direction, in a side view of the discharge route of the medium, it is possible to save a space for disposing the first medium receiving tray and the second medium receiving tray on the downstream side in the discharge direction, and the configuration can contribute to miniaturization of the apparatus. 
     According to a twelfth aspect, there is provided a medium discharge device including: a discharge unit that discharges a medium; a first medium receiving tray that receives the medium discharged by the discharge unit; and a second medium receiving tray that is provided above the first medium receiving tray in a vertical direction and receives the medium discharged by the discharge unit. The discharge unit has a first roller and a second roller that is provided to be capable of changing a position around the first roller and nips the medium in cooperation with the first roller, and the second roller changes a position around the first roller, and thereby a discharge destination of the medium is switched to any one of the first medium receiving tray and the second medium receiving tray. 
     When the second roller changes the position around the first roller, the discharge direction of the medium changes by the first roller and the second roller. According to the aspect, such performance causes the discharge destination of the medium to be switched to any one of the first medium receiving tray and the second medium receiving tray, and thus it is possible to configure the medium discharge device that is capable of sorting media to be discharged, in a simpler configuration, in a smaller size, and at lower costs, compared with a configuration in which the entire discharge unit moves upward and downward. 
     According to a thirteenth aspect, there is provided a recording apparatus including: a recording unit that performs recording on a medium; and the medium discharge device according to any one of the first to twelfth aspects which discharges the medium on which recording has been performed by the recording unit. 
     In the aspect, it is possible to achieve the same operation effects as those of any one of the first to twelfth aspects described above in the recording apparatus. 
     Hereinafter, embodiments will be described with reference to the drawings. The same reference signs are assigned to the same configurations in the embodiments, thus, only one embodiment is described first, and description of the configurations in the following embodiments is omitted. 
       FIG. 1  is a perspective view illustrating the external appearance of a printer according to a first embodiment.  FIG. 2  is a sectional side view illustrating a medium transport route in the printer according to the first embodiment.  FIG. 3  is a sectional side view illustrating a state in which a medium is discharged to a first medium receiving tray in the first embodiment. 
       FIG. 4  is a sectional side view illustrating a state in which a medium is discharged to a second medium receiving tray in the first embodiment.  FIG. 5  is a perspective view illustrating a state of the second medium receiving tray at a retraction position.  FIG. 6  is a perspective view illustrating a state of the second medium receiving tray at an advance position. 
       FIG. 7  is a sectional side view illustrating the retraction position of the second medium receiving tray.  FIG. 8  is a sectional side view illustrating a state in which a position of the second medium receiving tray is switched from the retraction position to the advance position.  FIG. 9  is a sectional side view illustrating the advance position of the second medium receiving tray. FIG.  10  is a sectional side view illustrating a relationship between the second medium receiving tray and a discharge roller pair at the advance position. 
       FIG. 11  is a sectional side view illustrating a discharge state to a first medium receiving tray according to a second embodiment.  FIG. 12  is a sectional side view illustrating a discharge state to a second medium receiving tray according to the second embodiment.  FIG. 13  is a sectional side view illustrating a discharge state to a third medium receiving tray according to the second embodiment. 
       FIG. 14  is a sectional side view illustrating a discharge state to a first medium receiving tray according to a third embodiment.  FIG. 15  is a sectional side view illustrating a discharge state to a second medium receiving tray according to the third embodiment.  FIG. 16  is a sectional side view illustrating a discharge state to a third medium receiving tray according to the third embodiment. 
     In addition, in an X-Y-Z coordinate system in the drawings, an X direction represents a width direction of a recording medium, that is, an apparatus width direction, a Y direction represents a transport direction of the recording medium in a transport route in the recording apparatus, that is, an apparatus depth direction, and a Z direction represents an apparatus height direction. 
     In the embodiment an X-Y plane is a horizontal plane. In addition, an X-Z plane and a Y-Z plane are vertical. 
     First Embodiment 
     Overview of Printer 
     In  FIG. 1 , a printer  10  as the “recording apparatus” is configured as a multifunction printer including an apparatus main body  12  and an image reading device  14 . The printer  10  is described as an ink jet printer as an example of the recording apparatus; however, the printer may be a recording apparatus such as a laser printer. In addition, the image reading device  14  includes a scanner, a FAX, or the like. 
     An operating unit  16  is provided on the apparatus main body  12  on a +Y-axis direction side thereof. The operating unit  16  is configured to have a power button, a print setting button, a display button, or the like for operating the printer  10 . A medium discharge device  18  is provided on a −Z direction side of the operating unit  16  on the +Y-axis direction side of the apparatus main body  12 . The medium discharge device  18  will be described below. 
     A medium accommodating unit  20  is provided on a −Z direction side of the medium discharge device  18  in the apparatus main body  12 . The medium accommodating unit  20  is configured to be capable of accommodating a plurality of media in the inside thereof and being attachable to and detachable from the apparatus main body  12  from the +Y direction side of the apparatus main body  12 . 
     Regarding Medium Transport Route 
     Subsequently, a medium transport route  22  of the medium P in the printer  10  in  FIG. 2  will be described. The medium accommodating unit  20  accommodates a plurality of media P. The media in the embodiment include media having different sizes such as a sheet of paper of A4 size or B5 size, photo paper, or a postcard. A two-dot chain line assigned with a reference sign P- 1  in  FIG. 2  represents a route of the medium P that is transported along the medium transport route  22 . 
     A first feed roller  24  that is rotatably driven by a drive source (not illustrated) is provided on a +Z direction side of the medium accommodating unit  20 . In this manner, when the first feed roller  24  feeds the medium P accommodated in the medium accommodating unit  20  to a downstream side on a transport route, the first feed roller comes into contact with the uppermost medium accommodated in the medium accommodating unit  20  so as to rotate, thereby feeding the uppermost medium to the downstream side in a feed direction from the medium accommodating unit  20 . A feed roller pair  26  is provided on the downstream side of the first feed roller  24 . 
     A first transport roller  28  and a second transport roller  30  are provided on the downstream side of the feed roller pair  26  in the feed direction. A plurality of driven rollers  32   a ,  32   b ,  32   c , and  32   d  are provided around the first transport roller  28  and the second transport roller  30  so as to be rotatably driven with respect to the first transport roller  28  and the second transport roller  30 . In addition, a transport roller pair  34  is provided on the downstream side of the first transport roller  28  and the second transport roller  30  in the transport direction. 
     A carriage  36  is provided on the downstream side of the transport roller pair  34  in the transport direction. The carriage  36  is configured to be capable of reciprocating in an apparatus width direction by a drive unit (not illustrated). A recording head  38  as a “recording unit” is provided in a lower portion of the carriage  36 . An underside of the recording head  38  is provided with a plurality of nozzles, and the recording head is configured to be capable of ejecting ink toward the medium P. In addition, a discharge roller pair  40  as a “discharge unit” is provided on the downstream side of the carriage  36  in the transport direction. 
     The medium P fed by the first feed roller  24  from the medium accommodating unit  20  is transported to a region facing the recording head  38  through the first transport roller  28 , the second transport roller  30 , and the transport roller pair  34 . In this manner, after the recording is executed by the recording head  38 , the medium P is discharged to a side surface side of the apparatus by the discharge roller pair  40 . 
     Regarding Medium Discharge Device 
     The medium discharge device  18  will be schematically described with reference to  FIGS. 3 and 4 . The medium discharge device  18  in the embodiment includes the discharge roller pair  40 , a first medium receiving tray  42 , and a second medium receiving tray  44 . The first medium receiving tray  42  in the embodiment projects from an end portion of the printer  10  on the +Y direction side toward the +Y direction side as illustrated in  FIG. 1 . The first medium receiving tray  42  is configured to be inclined in the +Z direction (upward) toward the +Y direction side. The first medium receiving tray  42  is provided with a medium support surface  42   a . The first medium receiving tray  42  is disposed to be inclined with respect to the apparatus main body  12  at a suitable angle so as to be capable of appropriately placing the medium P discharged to the medium support surface  42   a.    
     The second medium receiving tray  44  is provided on the +Z direction side of the first medium receiving tray  42 , that is, the second medium receiving tray  44  is provided above the first medium receiving tray  42  in the vertical direction. The description that “the second medium receiving tray  44  is provided above the first medium receiving tray  42  in the vertical direction” is provided by focusing only on a positional relationship in the vertical direction. Specifically, the meaning thereof is not limited to a configuration in which the second medium receiving tray  44  is provided right above the first medium receiving tray  42 , but also includes such a case where the second medium receiving tray  44  is not provided right above the first medium receiving tray  42 . That is, this means that a positional relationship of the first medium receiving tray  42  and the second medium receiving tray  44  in the Y-axis direction and a positional relationship thereof in an X-axis direction are meaningless. 
     In the embodiment, the first medium receiving tray  42  is fixed to the medium discharge device  18 . “Fixing” in the embodiment means that the first medium receiving tray  42  is not configured to move upward and downward like the sorter when the medium P is discharged. In the embodiment, the first medium receiving tray  42  may be configured to be attachable to and detachable from the medium discharge device  18  so as to be assembled or replaced. 
     A two-dot chain line assigned with a reference sign P- 2  in  FIG. 3  represents a discharge route of the medium P that is discharged to the first medium receiving tray  42  by the discharge roller pair  40 , a two-dot chain line assigned with a reference sign P- 3  in  FIG. 4  represents a discharge route of the medium P that is discharged to the second medium receiving tray  44  by the discharge roller pair  40 , and a dot-and-dash line assigned with a reference sign S 1  in  FIGS. 3 and 4  represents a tangential line at a nip position N 1  ( FIG. 10 ) in the discharge roller pair  40 . 
     In the embodiment, a passing route (discharge route) of the medium P, which is represented by P- 2  or P- 3  in  FIGS. 3 and 4  is only an example and varies depending on a rotation speed of the discharge roller pair  40 , a type of medium P, a landing state of ink to the medium, or the like. 
     In the embodiment, the second medium receiving tray  44  is configured to advance to the passing route (discharge route P- 2 ) of the medium P to be discharged from the discharge roller pair  40  toward the first medium receiving tray  42  and traverses the passing route (discharge route P- 2 ) so as to be capable of switching the position between the advance position ( FIG. 4 ) for receiving the medium P to be discharged and the retraction position ( FIG. 3 ) to which the second medium receiving tray retracts from the passing route (discharge route P- 2 ) of the medium P to be discharged from the discharge roller pair  40  toward the first medium receiving tray  42 . 
     Regarding Configuration of Second Medium Receiving Tray 
     A configuration of the second medium receiving tray  44  is described with reference to  FIGS. 5 to 10 . The second medium receiving tray  44  is provided with an upstream side zone  44   a  as an “upstream zone” in a medium transport direction, a downstream side zone  44   b  as a “downstream zone”, and a pair of frames  44   c . The frame  44   c  in the embodiment is disposed in both side portions of the second medium receiving tray  44  in the X-axis direction. The upstream side zone  44   a  is attached so as to be capable of changing a posture or a position thereof with respect to the frame  44   c  ( FIGS. 5 and 6 ). The downstream side zone  44   b  is provided to be fixed to the frame  44   c . “Fixing” in the embodiment means that the first downstream side zone  44   b  is not configured to change the position when the medium P is discharged. A configuration of providing by fixing in the embodiment also includes a configuration in which the downstream side zone  44   b  is attachable to and detachable from the apparatus main body  12  so as to be assembled or replaced. 
     The upstream side zone  44   a  is provided with a regulatory wall  44   d  that projects in the +Z direction in the end portion on the −Y direction side, as the “upstream side end portion”. The upstream side zone  44   a  is provided with an upstream side medium support surface  44   e  that receives the discharged medium P. The upstream side zone  44   a  is provided with a notch portion  44   f  at the center of the X-axis direction in the end portion on the +Y direction side. 
     A downstream side medium support surface  44   g  is provided on the top surface of the downstream side zone  44   b . A guide portion  44   h  that projects toward the −Y direction side at a position corresponding to the notch portion  44   f  of the upstream side zone  44   a  is formed at the end portion of the downstream side zone  44   b  on the −Y direction side. A guide surface  44   j  is formed on the top surface of the guide portion  44   h.    
     A drive shaft  46  that extends in the X-axis direction is rotatably attached to the pair of frames  44   c . An end portion of the drive shaft  46  on the +X direction side is connected to a drive force transmitting unit  50  that transmits a drive force of the drive motor  48 . The drive force transmitting unit  50  in the embodiment is configured of a plurality of gears (not illustrated) as an example and is configured to transmit the drive force of the drive motor  48  to the drive shaft  46 . With the drive motor  48 , as an example, a rotation direction, in which the upstream side zone  44   a  is moved from the retraction position to the advance position, is set as a forward rotation direction, and a rotation direction, in which the upstream side zone  44   a  is moved from the advance position to the retraction position, is set as a reverse rotation direction. 
     In the embodiment, a pair of drive gears  52  is fixed to the drive shaft  46  at an interval in the X-axis direction so as to rotate along with the drive shaft  46 . Each of the drive gears  52  intermeshes with a rack  54 . In the embodiment, the drive gears  52  and the racks  54  configure a rack and pinion mechanism. 
     A pair of side walls  44   k  that extends to the +Z-axis direction side is formed in both side portions of the upstream side zone  44   a  in the X-axis direction of the second medium receiving tray  44 . A rotary shaft  56  that extends in the X-axis direction is attached to the pair of side walls  44   k . In the embodiment, a part of the rotary shaft  56  is gripped on a back side of the rack  54 . 
     A rotary shaft  58  that extends in the X-axis direction is rotatably attached to the pair of frames  44   c . In the embodiment, a detection lever  60  is attached to a center portion of the rotary shaft  58  in the X-axis direction, specifically, a position corresponding to the guide surface  44   j  of the guide portion  44   h  in the X-axis direction. The detection lever  60  abuts the guide surface  44   j  in a case where the medium P is not placed in the second medium receiving tray  44 . 
     When the medium P is placed in the second medium receiving tray  44 , the detection lever  60  moves rotationally in a direction of separating from the guide surface  44   j  with the rotary shaft  58  as a rotary point, depending on a thickness of the placed media P. When a preset number of sheets are placed in the second medium receiving tray  44 , the detection lever  60  moves rotationally by a predetermined amount. The rotary operation is detected by a detection sensor (not illustrated). 
     As a result, the detection sensor (not illustrated) detects that a set number of media P are placed in the second medium receiving tray  44 . In this manner, a controller (not illustrated) disposed in the printer  10  issues an alarm for notifying that the predetermined number of media P are placed in the second medium receiving tray  44 , that is, a stack height of the media P on the second medium receiving tray  44  reaches an upper limit, for example, based on detection information of the detection sensor (not illustrated), or the controller displays a message on a display panel of the operating unit  16 . In addition, in a case where a stacked amount of the media P on the second medium receiving tray  44  reaches the upper limit, and in a case where the print job remains, the controller (not illustrated) pauses a print job temporarily or switches the discharge destination of the medium P to the first medium receiving tray  42 . 
     When the upstream side zone  44   a  is positioned at the advance position, in the embodiment, an inclination of the upstream side medium support surface  44   e  of the upstream side zone  44   a  is equal to an inclination of the downstream side medium support surface  44   g  of the downstream side zone  44   b ; however, when the upstream side zone  44   a  is positioned at the retraction position, the upstream side medium support surface  44   e  has an inclination gentler than the inclination of the downstream side medium support surface  44   g . Hence, as illustrated in  FIG. 17 , a bending portion Pr is formed to stacked media bundle Pt. When the detection lever  60  is disposed at a position that abuts the bending portion Pr, there is a concern that it is not possible to measure a stacked height of the media bundle Pt with accuracy; however, since the detection lever  60  is provided at a position that avoids the bending portion Pr, it is possible to measure the stacked height of the media bundle Pt with accuracy. 
     In addition, in order to detect the stacked height of the media bundle Pt with accuracy, it is also preferable to provide a holding member  95  that holds the media bundle Pt as illustrated in  FIG. 18 . The holding member  95  is provided to be capable of changing a position between a position (reference sign  95 _ 1 ) at which the holding member  95  holds the media bundle Pt by a drive unit (not illustrated) and a position (reference sign  95 _ 2 ) to which the holding member retracts from the media bundle Pt. The holding member  95  holds the media bundle Pt, and thereby it is possible for the detection lever  60  to detect the stacked height of the media bundle Pt with accuracy. 
     In particular, in a case of ink jet recording, the medium P absorbs ink and swells, and an air layer can be formed between media in the media bundle Pt. Therefore, there is a concern that it is not possible to detect the stacked height of the media bundle Pt with accuracy; however, the holding member  95  provided as described above makes it possible to detect the stacked height of the media bundle Pt with accuracy. 
     Since the swelling due to absorbing of ink by the medium P subsides as time elapses, the stacked height may be measured by the detection lever  60  after a predetermined time since the medium P has been discharged, instead of providing the holding member  95 . 
     Although not illustrated, a detection sensor is also provided in the first medium receiving tray  42 . When the predetermined sheets of media P are placed in the first medium receiving tray  42 , a detection state of the detection sensor provided in the first medium receiving tray  42  changes. Consequently, the predetermined sheets of media P are detected to be placed in the first medium receiving tray  42 , and a media discharge operation to the second medium receiving tray  44  is regulated. Specifically, a switching operation of the upstream side zone  44   a  from the retraction position to the advance position is regulated. Consequently, when the position of the upstream side zone  44   a  is switched from the retraction position to the advance position, it is possible to prevent the upstream side zone  44   a  from interfering with the medium P placed in the first medium receiving tray  42 . 
     As illustrated in  FIGS. 7 to 9 , the pair of frames  44   c  is each provided with a first guide groove  62  and a second guide groove  64 . The first guide groove  62  is formed as a downward inclined groove that descends toward the −Y direction side. The rotary shaft  56  is inserted into the first guide groove  62 . When the rack  54  is driven by the drive gears  52 , the rotary shaft  56  moves in the Y-axis direction in the first guide groove  62  along the first guide groove  62 . 
     A guide pin  66  is inserted into the second guide groove  64 . The guide pin  66  is configured to project in an outward direction of the second medium receiving tray  44  on the pair of side walls  44   k  of the second medium receiving tray  44 , specifically, to project in the +X-axis direction from the side wall  44   k  on the +X-axis direction side and in the −X-axis direction from the side wall  44   k  on the −X-axis direction side. 
     The second guide groove  64  extends in the Y-axis direction overall. The second guide groove  64  is provided with a support portion  64   a  that supports the guide pin  66  in a state in which the upstream side zone  44   a  is positioned at the retraction position, an angle changing portion  64   b  that extends from the support portion  64   a  toward the −Y direction side and the −Z direction side and changes an angle of the upstream side zone  44   a , and an advance/retraction portion  64   c  that extends from the angle changing portion  64   b  toward the −Y direction side and the −Z direction side. In the embodiment, an inclination angle to the −Z direction side in the angle changing portion  64   b  is set to be steeper than an inclination angle in the advance/retraction portion  64   c.    
     Subsequently, switching of the position of the upstream side zone  44   a  between the retraction position and the advance position will be described with reference to  FIGS. 7 to 9 .  FIG. 7  illustrates a state in which the upstream side zone  44   a  is positioned at the retraction position. In this state, the upstream side medium support surface  44   e  of the upstream side zone  44   a  is inclined in an upward direction (+Z-axis direction) toward a medium discharge direction (+Y-axis direction side) by an inclination angle θ 1  with respect to the Y axis (horizontal). The rotary shaft  56  is positioned at an end portion of the first guide groove  62  on the −Y direction side, and thus the guide pin  66  is supported by the support portion  64   a  of the second guide groove  64 . 
     In this state, the upstream side zone  44   a  is positioned on the more +Z direction side than a tangential line S 1  at the nip position N 1  ( FIG. 10 ) of the discharge roller pair  40 . When the upstream side zone  44   a  is positioned at the retraction position, the upstream side zone  44   a  does not block an advance direction of the medium P discharged by the discharge roller pair  40 , and thus the discharged medium P is discharged toward the first medium receiving tray  42 . 
     Subsequently, when a drive force (rotation in the forward rotation direction) of the drive motor  48  is transmitted to the drive gears  52  via the drive force transmitting unit  50 , the rack  54  moves toward the −Y direction side as represented by an arrow A 1  illustrated in  FIG. 8 . The rotary shaft  56  also moves toward the −Y direction side (refer to an arrow A 2 ) in the first guide groove  62 , along with the movement of the rack  54  toward the −Y direction side. 
     The movement of the rotary shaft  56  toward the −Y-axis direction side causes the upstream side zone  44   a  to move also toward the −Y-axis direction side. Hence, the guide pin  66  provided on the side wall  44   k  of the upstream side zone  44   a  also moves toward the −Y direction side from the support portion  64   a  of the second guide groove  64  and moves along the angle changing portion  64   b  (refer to an arrow A 3 ). In this case, the guide pin  66  moves in the −Z-axis direction along the angle changing portion  64   b  from the support portion  64   a  in the Z-axis direction. As a result, the upstream side zone  44   a  moves rotationally in a clockwise direction in  FIG. 8  with the rotary shaft  56  as a rotary point (refer to an arrow A 4 ). In other words, the regulatory wall  44   d  of the upstream side zone  44   a  changes a position toward the −Z direction side and intersects the tangential line S 1 . 
     Subsequently, as illustrated in  FIG. 9 , when the rack  54  further moves toward the −Y-axis direction side (refer to an arrow A 5 ), the rotary shaft  56  further moves toward the −Y direction side in the first guide groove  62  (refer to an arrow A 6 ) so as to be positioned at an end portion of first guide groove  62  on the −Y direction side. In this state, the guide pin  66  moves to the advance/retraction portion  64   c  through the angle changing portion  64   b  in the second guide groove  64  and is positioned at an end portion of the advance/retraction portion  64   c  on the −Y-axis direction side (refer to an arrow A 7 ). A position of the upstream side zone  44   a  illustrated in  FIG. 9  is the advance position of the upstream side zone  44   a.    
     As a result, the upstream side zone  44   a  further moves toward the −Y-axis direction side from the position in  FIG. 8  and comes into a state in  FIG. 9  (refer to an arrow A 8 ). In this state, the upstream side medium support surface  44   e  of the upstream side zone  44   a  comes into an inclined state in the upward direction (+Z-axis direction) toward the medium discharge direction (+Y-axis direction side) by an inclination angle θ 2  with respect to the Y axis. In the embodiment, the inclination angle θ 2  is set to an angle larger than the inclination angle θ 1 . Hence, the upstream side medium support surface  44   e  has a gentler inclined posture in a case of being positioned at the retraction position, compared with a case of being positioned at the advance position. 
     In the embodiment, the upstream side zone  44   a  is moved by switching an angle from the inclination angle θ 1  to the inclination angle θ 2  larger than the inclination angle θ 1 , and thereby it is possible to switch the position of the upstream side zone  44   a  from the retraction position to the advance position through a shorter movement distance than a movement distance of the upstream side zone at the inclination angle θ 1  as is. 
     As illustrated in  FIG. 10 , when the upstream side zone  44   a  is positioned at the advance position, the regulatory wall  44   d  of the end portion of the upstream side zone  44   a  on the −Y-axis direction side is positioned on the more −Z direction side than the nip position N 1  of the discharge roller pair  40  and the tangential line S 1  that passes through the nip position N 1  in the Z-axis direction, that is, the regulatory wall  44   d  that configures the end portion of the upstream side zone  44   a  on the upstream side is positioned below the nip position N 1  in the vertical direction. 
     The description that “the upstream side end portion (regulatory wall  44   d  in the embodiment) of the upstream side zone  44   a  is positioned below the nip position N 1  in the vertical direction” is provided by focusing only on the positional relationship in the vertical direction. Specifically, this also includes a state in which the upstream side end portion of the upstream side zone  44   a  is positioned right below the nip position N 1 , in addition to a state in which the upstream side end portion of the upstream side zone  44   a  is positioned below in the vertical direction although the upstream side end portion of the upstream side zone is displaced in the Y-axis direction with respect to the nip position N 1  as described in the embodiment and means that any positional relationship between the upstream side end portion of the upstream side zone  44   a  and the nip position N 1  in the Y-axis direction may be employed. Hence, in a range in which the upstream side medium support surface  44   e  can receive the medium P, any relationship between the upstream side end portion of the upstream side zone  44   a  and the nip position N 1  in the X-axis direction may be employed. 
     As described above, when the upstream side zone  44   a  is positioned at the advance position, the upstream side zone  44   a  blocks the discharge route P- 2  (also refer to  FIG. 3 ) of the medium P. Consequently, the medium P discharged from the discharge roller pair  40  comes into contact with the upstream side medium support surface  44   e  and is guided in the +Y-axis direction by the upstream side medium support surface  44   e . A two-dot chain line assigned with the reference sign P- 2  in  FIG. 10 , illustrates a part of the discharge route P- 2  of the medium P, specifically, only a region in the vicinity of the discharge roller pair  40 . 
     The discharge route P- 2  in  FIGS. 3 and 10  as described above varies depending on the rotation speed of the discharge roller pair  40 , a type of medium P, a landing state of ink to the medium, or the like. Hence, it is preferable that the discharge route P- 2  in a case where the most remarkable falling down of the medium occurs be assumed to determine the advance position of the upstream side zone  44   a . For example, when recording with the most remarkable wetting of ink is performed on a medium having the lowest stiffness of types of media assumed to be used, and the discharge route P- 2  in a case of discharging the medium at the lowest speed is assumed so as to determine the advance position of the upstream side zone  44   a , it is possible to stack the media in the second medium receiving tray  44 . 
     As described in the embodiment, when the upstream side end portion of the upstream side zone  44   a  is advanced to a position at which the upstream side end portion approaches the discharge roller pair  40 , the media can always be stacked in the second medium receiving tray  44 . 
     Here, as illustrated in  FIGS. 9 and 10 , the inclination (inclination angle θ 2 ) of the upstream side medium support surface  44   e  of the upstream side zone  44   a  at the advance position in the embodiment is set to be equal to the inclination of the downstream side medium support surface  44   g  of the downstream side zone  44   b . The equal inclination in the embodiment is not limited to the completely same inclination angle, and a deviation of an angle is allowed to the extent that the medium P is transported from the upstream side medium support surface  44   e  to the downstream side medium support surface  44   g  without being caught on the end portion of the downstream side zone  44   b  on the −Y direction side. 
     With reference to  FIGS. 7 to 9 , the position of the regulatory wall  44   d  of the upstream side zone  44   a  is positioned on the more −Y direction side in the Y-axis direction, in a case where the upstream side zone  44   a  is positioned at the advance position than in a case of being positioned at the retraction position, that is, the regulatory wall  44   d  is positioned at a position closer to the discharge roller pair  40  in a case of being positioned at the advance position than in a case of being positioned at the retraction position, and thereby the upstream side medium support surface  44   e  can be closer to the discharge roller pair  40 . Therefore, it is possible to reliably place the medium P to be discharged on the upstream side medium support surface  44   e.    
     As illustrated in  FIGS. 4, 6, and 10 , in the embodiment, the guide portion  44   h  that projects toward the notch portion  44   f  of the upstream side zone  44   a  is formed at the end portion of the downstream side zone  44   b  on the −Y-axis direction side. In the embodiment, an inclination of the guide surface  44   j  of the guide portion  44   h  is set to be equal to the inclination (inclination angle) of the downstream side medium support surface  44   g . The inclination angle of the guide surface  44   j  is not only completely equal to the inclination angle of the downstream side medium support surface  44   g , but also a deviation in angle is allowed to the extent that it is possible to smoothly transport the medium P. 
     In the embodiment, when the medium P is discharged from the discharge roller pair  40  in a state in which the upstream side zone  44   a  is positioned at the advance position, the medium P is guided toward the +Y-axis direction along the upward-inclined upstream side medium support surface  44   e . With reference to  FIG. 6 , in a state in which the upstream side zone  44   a  is positioned at the advance position, the guide portion  44   h  of the downstream side zone  44   b  moves out from the notch portion  44   f  of the upstream side zone  44   a.    
     In the embodiment, the notch portion  44   f  of the upstream side zone  44   a  is configured to cut out a part of the upstream side medium support surface  44   e , and thus the upstream side medium support surface  44   e  are formed in both side portions of the notch portion  44   f  in the X-axis direction. When the medium P is guided toward the +Y-axis direction side along the upstream side medium support surface  44   e  and reaches a position of the notch portion  44   f  in the Y-axis direction, the medium P is continuously guided toward the +Y-axis direction while being supported by regions that are positioned on both sides of the notch portion  44   f  in the X-axis direction in the upstream side medium support surface  44   e.    
     When the medium P reaches the end portion of the upstream side medium support surface  44   e  on the +Y-axis direction side, the center portion of the medium P in the width direction (X-axis direction) comes into contact with the guide surface  44   j  of the guide portion  44   h  of the downstream side zone  44   b . Then, while being supported by the guide surface  44   j , the medium P is guided in the +Y-axis direction. Further, when the medium P is sent toward the +Y-axis direction side, the medium passes over the guide surface  44   j  so as to be guided to the downstream side medium support surface  44   g.    
     As a result, the medium P discharged from the discharge roller pair  40  is supported by the second medium receiving tray  44 , specifically, by the upstream side medium support surface  44   e  of the upstream side zone  44   a  positioned at the advance position and the downstream side medium support surface  44   g  of the downstream side zone  44   b . In the embodiment, the end portion of the upstream side zone  44   a  on the −Y direction side is provided with the regulatory wall  44   d , and thus it is possible to regulate sliding-down of the discharged medium P in the upward inclined second medium receiving tray  44  on the +Y-direction side. 
     Here, when the rotation direction of the drive motor  48  is switched from the forward rotation direction to the reverse rotation direction, it is possible to move the upstream side zone  44   a  from the advance position to the retraction position. Specifically, the upstream side zone  44   a  moves in the reverse direction through a moving route from the retraction position to the advance position of the upstream side zone  44   a  described above, and the position of the upstream side zone is switched from the advance position to the retraction position. As an example, the rotation direction of the drive motor  48  is appropriately switched, and thereby it is possible to appropriately switch a state of the upstream side zone  44   a  between a state of being positioned at the retraction position and a state of being positioned at the advance position. 
     For example, the state of the second medium receiving tray  44  may be switched such that the plurality of media P are discharged alternately to the first medium receiving tray  42  and the second medium receiving tray  44 , or the predetermined number of media P are discharged to one of the first medium receiving tray  42  and the second medium receiving tray  44  and then are discharged to the other medium receiving tray. In other words, a discharge destination medium tray may be appropriately switched depending on discharge of the medium P. 
     In the embodiment, in  FIGS. 4 and 9 , inclinations of the upstream side medium support surface  44   e  and the downstream side medium support surface  44   g  of the second medium receiving tray  44  in a state in which the upstream side zone  44   a  of the second medium receiving tray  44  is positioned at the advance position are set to be equal to the inclination (inclination angle) of the medium support surface  42   a  of the first medium receiving tray  42 . In the embodiment, the equal inclination of the upstream side medium support surface  44   e  and the downstream side medium support surface  44   g  and the medium support surface  42   a  includes not only the complete equal state but also a deviation in angle due to component accuracy or an attachment error occurring during assembly. 
     In the embodiment, the position of the second medium receiving tray  44  is appropriately switched between the retraction position and the advance position, and thereby it is possible to switch the discharge destination of the medium P that is discharged from the discharge roller pair  40  between the first medium receiving tray  42  and the second medium receiving tray  44 . As a result, since there is no need to provide the discharge roller pair  40  for each medium receiving tray  42  or  44 , and there is no need to synchronize the plurality of discharge roller pairs  40  with each other, it is possible to suppress a reduction in paper feed accuracy or printing accuracy. Additionally, since it is possible to configure the discharge roller pair  40  by one set, it is possible to sort the media P to be discharged, in a simple configuration, and it is possible to configure the medium discharge device  18  in a small size and at low costs. 
     The discharge roller pair  40  shares a common drive source with the other transport rollers, and thus the discharge roller pair rotates reversely when duplex printing is performed. In a case where the discharge roller pair  40  rotates reversely in a state in which the upstream side zone  44   a  is positioned at the advance position, there is a concern that an upstream end of the medium P discharged to the second medium receiving tray  44  will touch the discharge roller pair  40  and be drawn into the apparatus. In particular, such a problem easily occurs in a case where the inclination angle of the second medium receiving tray  44  is a steep angle. Hence, in a case where the discharge roller pair  40  rotates reversely, it is preferable that the position of the second medium receiving tray  44  be switched to the retraction position. 
     Otherwise, it is preferable to provide a shutter member  96  as illustrated in  FIG. 19 . The shutter member  96  is provided to be capable of changing a position between a position (reference sign  96 _ 1 ) at which the shutter member blocks the discharge route of the medium P by a drive unit (not illustrated) and a position (reference sign  96 _ 2 ) at which the shutter member opens the discharge route of the medium P. In an example of  FIG. 19 , the shutter member  96  intersects the tangential line S 1  at the nip position N 1  of the discharge roller pair  40  at a position at which the shutter member blocks the discharge route of the medium P. 
     The shutter member  96  can prevent the problem from arising in that the upstream end of the medium P discharged to the second medium receiving tray  44  touches the discharge roller pair  40  and be drawn into the apparatus. 
     The shutter member  96  may be a rigid body or may be formed of a flexible member such as a film-shaped member. 
     To summarize the above description, the medium discharge device  18  includes the discharge roller pair  40  that discharges the medium, the first medium receiving tray  42  that receives the discharged medium, and the second medium receiving tray  44  that is provided on the more +Z direction side than the first medium receiving tray  42  in the Z-axis direction and receives the discharged medium P. The second medium receiving tray  44  is capable of changing the position between the advance position for receiving the medium P, which is discharged, by causing at least the upstream side zone  44   a  of the tray including the end portion on the −Y-axis direction side in the Y-axis direction to advance to the discharge route P- 2  ( FIGS. 3 and 10 ) of the medium P from the discharge roller pair  40  toward the first medium receiving tray  42  and the retraction position to which the upstream zone retracts from the passing route. 
     In the configuration described above in which the first medium receiving tray  42  and the second medium receiving tray  44  are provided, at least the upstream side zone  44   a  of the second medium receiving tray  44  changes a position, and thereby it is possible to switch the discharge destination of the medium P. In other words, since there is no need to employ a configuration in which all of the trays including the first medium receiving tray  42  and the second medium receiving tray  44  move upward and downward, and there is no need to employ a configuration in which the discharge roller pair  40  moves upward and downward, it is possible to provide the medium discharge device  18  that is capable of sorting media P to be discharged, in a simpler configuration, in a small size, and at low costs. 
     The discharge roller pair  40  is configured of the discharge roller pair that nips and discharges the medium P. When the upstream side zone  44   a  of the second medium receiving tray  44  is positioned at the advance position, the upstream side zone  44   a  intersects the tangential line S 1  at the nip position N 1  of the discharge roller pair  40 . According to the configuration, it is possible to more reliably place the medium P to be discharged from the discharge roller pair  40  in the second medium receiving tray  44 . 
     The discharge roller pair  40  is configured of the discharge roller pair that nips and discharges the medium P. When the upstream side zone  44   a  of the second medium receiving tray  44  is positioned at the advance position, the upstream side end portion is positioned on the more −Z direction side in the Z-axis direction than the nip position N 1  of the discharge roller pair  40 . According to the configuration, it is possible to more reliably place the medium P to be discharged from the discharge roller pair  40  in the second medium receiving tray  44 . 
     The upstream side medium support surface  44   e  provided in the upstream side zone  44   a  of the second medium receiving tray  44  is formed into the inclined surface ascending toward the +Z direction side in the +Y-axis direction with respect to the horizontal, and the inclination angle of the inclined surface with respect to the horizontal is larger in the case where the upstream side zone  44   a  is positioned at the advance position than in the case where the upstream side zone is positioned at the retraction position. According to the configuration, it is possible to secure a wide space below the upstream side zone  44   a  in the case where the upstream side zone  44   a  is positioned at the retraction position, and thus it is possible to suppress interference of the upstream side zone  44   a  with the discharge of the medium P to the first medium receiving tray  42 . 
     When the upstream side zone  44   a  of the second medium receiving tray  44  is positioned at the advance position, the upstream side medium support surface  44   e  and the downstream side medium support surface  44   g  provided in the second medium receiving tray  44  and the medium support surface  42   a  provided in the first medium receiving tray  42  are all inclined upward in the same degree toward the +Y-axis direction. In the embodiment, the first medium receiving tray  42  is disposed at the inclination (angle) suitable for placing the medium P, and the second medium receiving tray  44  and the first medium receiving tray  42  are inclined at the same degree. Therefore, it is possible to suitably place the discharged medium P. 
     The second medium receiving tray  44  is configured to have the upstream side zone  44   a  and the downstream side zone  44   b  that is provided to be fixed on the more +Y-axis direction than the advanceable/retractable upstream side zone  44   a  between the retraction position and the advance position. According to the configuration, there is no need for the entire second medium receiving tray  44  to perform a position changing movement, and thus it is possible to avoid an increase in configuration of the apparatus. 
     When the upstream side zone  44   a  of the second medium receiving tray  44  is positioned at the advance position, the upstream side medium support surface  44   e  provided in the upstream side zone  44   a  and the downstream side medium support surface  44   g  provided in the downstream side zone  44   b  are both inclined toward the +Z-axis direction in the +Y-axis direction with respect to the horizontal in the same degree. According to the configuration, it is possible to appropriately stack the media P to be discharged, in a natural shape. 
     The guide portion  44   h  is provided to guide the medium P from the upstream side medium support surface  44   e  provided in the upstream side zone  44   a  to the downstream side medium support surface  44   g  provided in the downstream side zone  44   b , when the upstream side zone  44   a  is positioned at the advance position. According to the configuration, it is possible to smoothly advance the medium P from the upstream side zone  44   a  to the downstream side zone  44   b.    
     The guide surface  44   j , on which the guide portion  44   h  guides the medium P, is inclined at the same degree as the downstream side medium support surface  44   g  provided in the downstream side zone  44   b . According to the configuration, it is possible to smoothly advance the medium P, when the medium advances from the guide surface  44   j  to the downstream side zone  44   b.    
     The upstream side end portion of the second medium receiving tray  44  is provided with the regulatory wall  44   d  that regulates a tail end of the discharged medium P. According to the configuration, it is possible to suppress sliding-down of the medium P from the second medium receiving tray  44 . 
     The printer  10  includes the recording head  38  that performs recording on the medium P and the medium discharge device  18  that discharges the medium P on which the recording has been performed by the recording head  38 . 
     Second Embodiment 
     A second embodiment of the medium discharge device in  FIGS. 11 to 13  is described. A medium discharge device  68  in the embodiment includes a first medium receiving tray  70  and a plurality of second medium receiving trays  72  and  74 . In  FIGS. 11 to 13 , configurations other than the medium discharge device  68 , the discharge roller pair  40 , the first medium receiving tray  70 , and the plurality of second medium receiving trays  72  and  74  are omitted. In the embodiment, a configuration of the first medium receiving tray  70  is the same as the configuration in the first embodiment, and thus the description thereof is omitted. 
     The second medium receiving tray  72  in the embodiment is different from the second medium receiving tray  44  in the first embodiment, and the entire tray is configured to change a position thereof between the retraction position (a two-dot chain line portion assigned with a reference sign  72 - 1  in  FIG. 12 ) and the advance position (a solid line portion assigned with a reference sign  72  in  FIG. 12 ). 
     The second medium receiving tray  74  in the embodiment is disposed in between the first medium receiving tray  70  and the second medium receiving tray  72  in the Z-axis direction. The second medium receiving trays  72  and  74  in the embodiment are each configured to be capable of switching a position between the retraction position and the advance position. 
     In the embodiment, the first medium receiving tray  70  and the plurality of second medium receiving trays  72  and  74  are radially disposed. Radial disposition thereof is specifically described. A gap between the first medium receiving tray  70  and the second medium receiving tray  72  is set to be narrowed as the trays approach the discharge roller pair  40  and to be widened as the trays are separated from the discharge roller pair  40 . Similarly, a gap between the second medium receiving tray  72  and the second medium receiving tray  74  is set to be narrowed as the trays approach the discharge roller pair  40  and to be widened as the trays are separated from the discharge roller pair  40 . 
     In other words, the gaps between the trays are set to be narrowed on a side on which the trays approach the discharge roller pair  40  and to be widened on a side on which the trays are separated from the discharge roller pair. Hence, since a gap between adjacent trays of the first medium receiving tray  70  and the plurality of second medium receiving trays  72  and  74  is widened toward the discharge direction in the configuration, it is possible to easily insert a hand of a user between the trays  70 ,  72 , and  74 , and it is possible to easily take out the medium P discharged to the trays  70 ,  72 , and  74 . 
       FIG. 11  illustrates a state in which the second medium receiving trays  72  and  74  are both positioned at the retraction position. In this state, since the second medium receiving trays  72  and  74  do not block a discharge route P- 4  of the medium P discharged by the discharge roller pair  40 , the medium P is discharged toward the first medium receiving tray  70  and is supported on the first medium receiving tray  70 . A two-dot chain line assigned with a reference sign P- 4  represents a discharge route of the medium P discharged toward the first medium receiving tray  70  from the discharge roller pair  40 . 
     Subsequently, as illustrated in  FIG. 12 , a position of the second medium receiving tray  72  is switched between the retraction position and the advance position (refer to an arrow A 9  and an arrow A 10 ). A switching operation from the retraction position to the advance position in the second medium receiving tray  72  is the same as the operation in the first embodiment. The two-dot chain line portion assigned with the reference sign  72 - 1  in  FIG. 12  represents the second medium receiving tray  72  positioned at the retraction position, and the solid line portion assigned with the reference sign  72  represents the second medium receiving tray  72  positioned at the advance position. 
     When the second medium receiving tray  72  is positioned at the advance position, at least a part of the second medium receiving tray  72  is positioned on the more −Z direction side than the nip position N 1  of the discharge roller pair  40 . In this state, when the discharge roller pair  40  discharges the medium P, the second medium receiving tray  72  blocks the discharge route P- 4  ( FIG. 11 ) of the medium P toward the first medium receiving tray  70 . As a result, the medium P discharged by the discharge roller pair  40  is not supported by the first medium receiving tray  70  but is supported by the second medium receiving tray  72  so as to be placed in the second medium receiving tray  72 . A two-dot chain line assigned with a reference sign P- 5  represents a discharge route of the medium P discharged toward the second medium receiving tray  72  from the discharge roller pair  40 . 
     As illustrated in  FIG. 13 , a position of the second medium receiving tray  74  is switched between the retraction position and the advance position (refer to an arrow A 11 ). In the embodiment, the second medium receiving tray  74  is configured to retract and advance between the retraction position and the advance position by a drive motor and a drive force transmitting unit (both not illustrated). Specifically, similarly to the first embodiment, as an example, the second medium receiving tray  74  is configured to be moved by the rack and pinion. A two-dot chain line portion assigned with a reference sign  74 - 1  in  FIG. 13  represents the second medium receiving tray  74  positioned at the retraction position, and a solid line portion assigned with the reference sign  74  represents the second medium receiving tray  74  positioned at the advance position. 
     When the second medium receiving tray  74  is positioned at the advance position, at least a part of the second medium receiving tray  74  is positioned on the more −Z direction side than the nip position N 1  of the discharge roller pair  40 . In this state, when the discharge roller pair  40  discharges the medium P, the second medium receiving tray  74  blocks the discharge route P- 4  ( FIG. 11 ) of the medium P toward the first medium receiving tray  70 . As a result, the medium P discharged by the discharge roller pair  40  is not supported by the first medium receiving tray  70  but is supported by the second medium receiving tray  74  so as to be placed in the second medium receiving tray  74 . A two-dot chain line assigned with a reference sign P- 6  represents a discharge route of the medium P discharged toward the second medium receiving tray  74  from the discharge roller pair  40 . 
     In the embodiment, the positions of the second medium receiving trays  72  and  74  are appropriately switched between the retraction position and the advance position, and thereby it is possible to switch the discharge destination of the medium P that is discharged from the discharge roller pair  40  to any one of the plurality of discharge trays. As a result, it is possible to sort the media P to be discharged in a simple configuration, and it is possible to configure the medium discharge device  68  in a small size and at low costs. 
     The medium discharge device  68  in the embodiment includes the plurality of second medium receiving trays  72  and  74 . The first medium receiving tray  70  and the second medium receiving trays  72  and  74  are disposed radially toward the downstream side in the discharge direction, in a side view of the discharge route of the medium P. According to the configuration, it is possible to save a space for disposing the first medium receiving tray  70  and the second medium receiving trays  72  and  74  on the downstream side in the discharge direction, and the configuration can contribute to miniaturization of the apparatus. 
     Modification Embodiment of Second Embodiment 
     The second medium receiving tray  72  in the embodiment has the configuration in which the entire tray moves rotationally between the retraction position and the advance position so as to retract and advance; however, instead of the configuration, similarly to the first embodiment, the second medium receiving tray  72  may have a configuration in which the upstream side zone and the downstream side zone are provided on the tray, and only the upstream side zone is caused to retract or advance between the retraction position and the advance position. 
     Third Embodiment 
     A third embodiment of the medium discharge device is described with reference to  FIGS. 14 to 16 . The embodiment differs from the first embodiment and the second embodiment in that a driven roller  76   b  is provided to be capable of changing a position thereof around a drive roller  76   a  in a discharge roller pair  76 , and the discharge route of the medium P is changed. 
     A medium discharge device  78  in the embodiment includes the discharge roller pair  76 , a first medium receiving tray  80 , second medium receiving trays  82  and  84 , and a driven roller driving unit  86 . In the embodiment, the second medium receiving trays  82  and  84  are different from those of the second embodiment and are fixed to the medium discharge device  78 . Also in the embodiment, similarly to the second embodiment, the first medium receiving tray  80  and the second medium receiving trays  82  and  84  may be radially disposed. 
     The discharge roller pair  76  includes the drive roller  76   a  as a “first roller” and the driven roller  76   b  as a “second roller”. The driven roller driving unit  86  includes a drive motor  88 , gears  90 A,  90 B, and  90 C, and a swinging arm  92 , as an example. The gear  90 A is attached to a drive shaft of the drive motor  88  and functions as a drive gear. The gear  90 C is connected to one end of the swinging arm  92 , and the driven roller  76   b  is rotatably attached to the other end thereof. The swinging arm  92  is configured to be rotatable with one end side as a rotary point. 
     As illustrated in  FIGS. 14 to 16 , when the drive motor  88  rotates, the gears  90 A,  90 B, and  90 C rotate sequentially, and the swinging arm  92  moves rotationally with one end side as a fulcrum. The driven roller  76   b  moves rotationally around the drive roller  76   a  due to the rotational movement. As a result, it is possible to appropriately change the nip position in the discharge roller pair  76 . 
     In  FIG. 14 , the nip position in the discharge roller pair  76  is set as N 2 . A dot-and-dash line assigned with a reference sign S 2  represents a tangential line at the nip position N 2  of the discharge roller pair  76 . As illustrated in  FIG. 14 , the tangential line S 2  does not intersect the second medium receiving trays  82  and  84  and extends toward the first medium receiving tray  80 . The medium P, which is nipped by the discharge roller pair  76  at the nip position N 2  so as to be discharged, is discharged to the first medium receiving tray  80  along a route represented by a reference sign P- 7 . 
     Subsequently, the drive motor  88  is rotated as illustrated in  FIG. 15 , and the swinging arm  92  is caused to swing such that the nip position in the discharge roller pair  76  is switched from the nip position N 2  to the nip position N 3 . Consequently, a tangential line at the nip position of the discharge roller pair  76  is changed from the tangential line S 2  to a tangential line S 3 . The tangential line S 3  extends toward the +Z direction of the second medium receiving tray  82  through the nip position N 3 . The medium P, which is nipped by the discharge roller pair  76  at the nip position N 3  so as to be discharged, is discharged to the second medium receiving tray  82  along a route (two-dot chain line) represented by a reference sign P- 8 . 
     In  FIG. 16 , when the nip position in the discharge roller pair  76  is switched from the nip position N 3  to the nip position N 4 , the tangential line at the nip position of the discharge roller pair  76  is changed from the tangential line S 3  to a tangential line S 4 . The tangential line S 4  passes through the nip position N 4 , does not intersect the second medium receiving tray  82 , and extends toward the second medium receiving tray  84 . The medium P, which is nipped by the discharge roller pair  76  at the nip position N 4  so as to be discharged, is discharged to the second medium receiving tray  84  along a route (two-dot chain line) represented by a reference sign P- 9 . 
     In the embodiment, the position of the driven roller  76   b  changes around the drive roller  76   a , and thereby it is possible to change the discharge direction of the medium P. Consequently, it is possible to switch the discharge destination of the medium P that is discharged from the discharge roller pair  76  to any one of the plurality of medium receiving trays  80 ,  82 , and  84 . 
     Here, when a configuration in which the position of the drive roller  76   a  changes around the driven roller  76   b  is employed, a unit that transmits a drive force from a drive source (not illustrated) to the drive shaft of the drive roller  76   a  and a drive shaft also needs to change a position thereof along with the position change of the drive roller  76   a , and thus a configuration of the apparatus is complicated. By comparison, in the embodiment, since a configuration in which the position of the driven roller  76   b  changes around the drive roller  76   a  is employed, it is possible to more simplify the configuration in which the position of the driven roller  76   b  changes with respect to the drive roller  76   a , compared with the configuration in which the position of the drive roller  76   a  changes around the driven roller  76   b . As a result, it is possible to sort the media P to be discharged, in a simple configuration, and it is possible to configure the medium discharge device  78  in a small size and at low costs. 
     The medium discharge device  78  includes the discharge roller pair  76  that discharges the medium P, the first medium receiving tray  80  that receives the medium P discharged by the discharge roller pair  76 , and the second medium receiving trays  82  and  84  that are provided on the more +Z direction side than the first medium receiving tray  80  in the Z-axis direction and receives the medium P discharged by the discharge roller pair  76 . The discharge roller pair  76  has the drive roller  76   a  and the driven roller  76   b  that is provided to be capable of changing a position thereof around the drive roller  76   a  and nips the medium P in cooperation with the drive roller  76   a , the driven roller  76   b  changes a position thereof around the drive roller  76   a , and thereby the discharge destination of the medium P is switched to any one of the first medium receiving tray  80  and the second medium receiving trays  82  and  84 . 
     When the driven roller  76   b  changes the position around the drive roller  76   a , the discharge direction of the medium P changes by the drive roller  76   a  and the driven roller  76   b . According to the configuration, such performance causes the discharge destination of the medium P to be switched to any one of the first medium receiving tray  80  and the second medium receiving trays  82  and  84 , and thus it is possible to configure the medium discharge device  78  that is capable of sorting the media P to be discharged, in a simpler configuration, in a smaller size, and at lower costs, compared with a configuration in which the entire discharge roller pair  76  moves upward and downward. 
     In addition, in the embodiment, the first medium receiving trays  42 ,  70 , and  80  and the second medium receiving trays  44 ,  72 ,  74 ,  82 , and  84  are applied to the ink jet printer as an example of the recording apparatus; however, the medium receiving trays can be applied to another common liquid ejecting apparatus. 
     Here, examples of the liquid ejecting apparatus are not limited to recording apparatuses such as a printer, a copy machine, and a facsimile in which an ink jet type recording head is used, ink is ejected from the recording head, and recording is performed on a recording medium, but include an apparatus in which, instead of the ink, a liquid corresponding to an application is ejected from a liquid ejecting head corresponding to the ink jet type recording head on an ejecting medium corresponding to the recording medium and the liquid is attached to the ejecting medium. 
     Examples of liquid ejecting heads include, in addition to the recording head, a color material ejecting head that is used in manufacturing a color filter of a liquid crystal display or the like, an electrode material (conductive paste) ejecting head that is used in forming electrodes of an organic EL display, a field emission display (FED), or the like, a bioorganic material ejecting head that is used in manufacturing a biochip, a sample ejecting head as an accuracy pipette, or the like. 
     The disclosure is not limited to the examples, various modifications can be performed within a range of the disclosure described in What is claimed is, and it is needless to say that the modifications are also included in the range of the disclosure.