Abstract:
An image recording device may include corrugate mechanisms to prevent undesired bending and jamming of a recording sheet. In some examples, the image recording device may include a first corrugate mechanism, a second corrugate mechanism and a third corrugate mechanism. The first, second and third corrugate mechanisms may be configured to create a corrugated shape in a recording sheet. The second and third corrugate mechanisms, in one or more arrangements, may be located downstream of the first corrugate mechanism and an ink nozzle. The third corrugate mechanism may further be configured such that no upper contact portion thereof may be disposed at a same position, with respect to the width direction, as endmost upper contact portions of the first corrugate mechanism with respect to the width direction. In yet other examples, the third corrugate mechanism may be located downstream of a reverse sheet conveying path.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from Japanese Patent Application No. 2012-104097, filed on Apr. 27, 2012, which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     Aspects described herein relate to an image recording apparatus that records an image onto a sheet while conveying the sheet maintained in a specified shape. 
     BACKGROUND 
     A known image recording apparatus is configured to convey a sheet by a conveyor roller pair while holding the sheet by a platen, record an image onto the sheet held by the platen by ejecting ink droplets from a recording head, and discharge the sheet having the recorded image by a discharge roller pair. 
     The known image recording apparatus includes a plurality of ribs disposed on the platen, a recording-sheet pressing plate, and a plurality of spurs. The recording sheet-pressing plate is disposed between the conveyor roller pair (including a sheet-feed drive roller and a registration roller) and the recording head with respect to a conveying direction. The plurality of spurs are disposed between the recording head and the discharge roller pair (including a sheet-discharge drive roller and sheet discharge spurs) with respect to the conveying direction. 
     The plurality of ribs extend parallel to the conveying direction and define grooves therebetween. The recording-sheet pressing plate includes a plurality of protrusions that protrude toward the respective grooves. The plurality of spurs are located in the respective grooves. While the sheet passes between the ribs and the protrusions, the sheet is pressed by the ribs and the protrusions in opposite directions. Therefore, the sheet is formed into a corrugated shape such that the sheet has ridge portions that are held by the ribs and groove portions that are depressed by the protrusions. The corrugated sheet is conveyed while the ridge portions are held by the ribs of the platen, respectively. After the sheet passes the platen, the groove portions of the sheet are depressed by the spurs. 
     SUMMARY 
     In the known image recording apparatus, the recording head may continue to eject ink droplets after a trailing edge of the sheet passes the conveyor roller pair with respect to the conveying direction. Therefore, the known image recording apparatus may need to be provided with pressing members (e.g., the plurality of spurs) that press the sheet to maintain the sheet in the corrugated shape after the trailing edge of the sheet passes the conveyor roller pair. However, when the corrugated sheet contacts a sheet discharge tray, both ends of the corrugated sheet with respect to a width direction orthogonal to the conveying direction may be caught on the sheet discharge tray, and thus, a paper jam may occur. In addition, the corrugated sheet may push one or more sheets that are held on the sheet discharge tray out of the sheet discharge tray. 
     Accordingly, aspects described herein provide for an image recording apparatus for recording an image on a corrugated sheet, and a configuration that may prevent or reduce an occurrence of a paper jam and falling or bending of a sheet (e.g., held on a sheet discharge tray). In one example, the image recording apparatus may include a first corrugate mechanism, a second corrugate mechanism and a third corrugate mechanism. The second and third corrugate mechanisms may be disposed downstream from nozzles of a recording device of the image recording apparatus. In some arrangements, a corrugate mechanism (e.g., the third corrugate mechanism) may be disposed downstream of a reverse conveying path of the image recording apparatus. 
     According to the one or more aspects, no upper contact portion of the third corrugate mechanism might be disposed at a position corresponding to the endmost first upper contact portions of the first corrugate mechanism with respect to the width direction. Therefore, groove portions of side edges of the corrugated sheet in the width direction are not depressed by the third contact portion. Accordingly, in some examples, an occurrence of the side edges of the corrugated sheet being caught on a holding surface of the sheet discharge tray and/or the discharged corrugated sheet pushing one or more sheets held on the sheet discharge tray out of the sheet discharge tray may be reduced. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure, needs satisfied thereby, and the objects, features, and advantages thereof, reference now is made to the following descriptions taken in connection with the accompanying drawing. 
         FIG. 1  is a perspective view depicting an appearance of an image recording apparatus in an illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 2  is a schematic longitudinal sectional view depicting an internal structure of a printer unit in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 3  is a perspective view depicting a portion in the vicinity of a platen in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 4  is a bottom view depicting a recording head in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 5  is a plan view depicting a sheet discharge tray in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 6  is a front view depicting contact portions and the platen when a sheet passes between the contact portions and the platen in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 7  is a front view depicting first discharge rollers and spurs when the sheet passes between the first discharge rollers and the spurs in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 8  is a front view depicting second discharge rollers and spurs when the sheet passes between the second discharge rollers and the spurs in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 9  is a plan view depicting an arrangement of a conveyor roller, the first discharge rollers, the second discharge roller, and the spurs in the illustrative embodiment according to one or more aspects of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     An illustrative embodiment according to one or more aspects is described below with reference to the accompanying drawings. The illustrative embodiment described below is only example. Various changes, arrangements and modifications may be applied therein without departing from the spirit and scope of the disclosure. 
     As depicted in  FIG. 1 , an image recording apparatus  10  may comprise a printer unit  11  and a scanner unit  12 . The printer unit  11  may be configured to record an image onto a sheet  100 . The scanner unit  12  may be configured to scan an image recorded on a document. The image recording apparatus  10  may be configured to perform one or more of printing, scanning, and copying. In some examples, I image recording apparatus  10  might not necessarily comprise the scanner unit  12 , whose detailed description is omitted. An up-down direction  101  may be defined with reference to an orientation of the image recording apparatus  10  in which it may be intended to be used. A side of the image recording apparatus  10 , in which a display panel  16  may be disposed, may be defined as the front of the image recording apparatus  10 . A front-rear direction  102  may be defined with reference to the front of the recording apparatus  10 . A right-left direction  103  may be defined with respect to the image recording apparatus  10  as viewed from its front. 
     As depicted in  FIG. 1 , a housing  14  may have a substantially rectangular parallelepiped shape. The display panel  16  may be disposed on an upper part of the front of the housing  14 . The housing  14  may have an opening  15  below the display panel  16 . A sheet feed tray  20  may be configured to be attached to the inkjet recording apparatus  10  via the opening  15 . The display panel  16  may have a rectangular plate-like shape elongated in the right-left direction  103 . The display panel  16  may comprise a support shaft (not depicted) on both sides of an upper end of the display panel  16  in the right-left direction  103 . The support shaft may be rotatably supported by the housing  14 . Therefore, the display panel  16  may be configured to pivot about an axis of the support shaft extending along the right-left direction  103  at the upper end while a lower end of the display panel  16  may be a moving end. A grip portion  17  may be disposed on a left lower end of the display panel  16  to allow a user to pivot the display panel  16  by pinching the grip portion  17 , as viewed from the front of the display panel  16 . 
     As depicted in  FIG. 1 , the sheet feed tray  20  may be disposed in a lower part of the housing  14 . The sheet feed tray  20  may be configured to be pulled out toward the front with respect to the housing  14 . The sheet feed tray  20  may be configured to accommodate one or more stacked sheets  100  subject to image recording. The sheet feed tray  20  may be configured to accommodate one or more sheets  100  of various sizes and types. 
     As depicted in  FIG. 2 , a guide member  21  may be disposed in the sheet feed tray  20 . The guide member  21  may be configured to move in accordance with the size of the one or more sheets  100  placed on the sheet feed tray  20 . Both side edges of the one or more sheets  100  with respect to the right-left direction  103  and upstream edges (e.g., a rear edge) of the one or more sheets  100  with respect to a sheet feeding direction  104  may be positioned by the guide member  21 . 
     An inclined wall  22  may be disposed on a rear end of the sheet feed tray  20 . The inclined wall  22  may be extend obliquely upward in the sheet feed direction  104 . The inclined wall  22  may have substantially the same width as a width of the sheet feed tray  20  in the right-left direction  103 . When a sheet  100  is fed from the sheet feed tray  20  in the sheet feed direction  104 , a leading edge of the sheet  100  may come into contact with the inclined wall  21  and then may be directed upward. As a result, the sheet  100  may enter a first conveying path  31 . 
     As depicted in  FIG. 2 , a feed roller  43  may be disposed above the sheet feed tray  20 . The feed roller  43  may be configured to rotate about an axis extending along the right-left direction  103 . The feed roller  43  may be rotatably supported by one end of an arm  42  that may extend obliquely downward while the other end of the arm  42  serves as a rotation shaft. The arm  42  may be configured to pivot such that the one end thereof may move in the up-down direction  101 . The feed roller  43  may be configured to move in the up-down direction  101  while changing a distance between the feed roller  43  and the sheet feed tray  20 , in accordance with the pivot of the arm  42 . The arm  42  may pivot downward by its own weight. Therefore, the feed roller  43  may be in contact with an uppermost sheet  100  of the plurality of sheets  100  accommodated in the sheet feed tray  20 . The feed roller  43  may be configured to be rotated by transmission of a drive force from a motor (not depicted). As the feed roller  43  is rotated, the uppermost sheet  100  that may be in contact with the feed roller  43  may be fed in the sheet feed direction  104 . 
     As depicted in  FIG. 2 , the first conveying path  31  through which a sheet  100  may be conveyed may be defined inside the housing  14 . The first conveying path  31  may be curved upward from an upper end of the inclined wall  22  and extend toward the front from the rear of the image forming apparatus  10 . The first conveying path  31  may be defined by a pair of guide members (not depicted) that may face each other while allowing a space therebetween for a sheet  100  to pass therethrough. 
     As depicted in  FIG. 2 , a second conveying path  32  may be defined inside the housing  14 . The second conveying path  32  may be used to convey a sheet  100  in double-sided printing. The second conveying path  32  may extend from a position that may be located between a first discharge roller  37  and a second discharge roller  55  in the first conveying path  31  to a position in a curved section of the first conveying path  31  that may be located upstream of a conveyor roller  35  with respect to the conveying direction  105 . The second conveying path  32  may be defined by defining members  70 ,  71  that may face each other while allowing a space therebetween for a sheet  100  to pass therethrough. 
     As depicted in  FIG. 2 , the conveyor roller  35  and following rollers  36  may be disposed downstream of the U-shaped curved section of the first conveying path  31  with respect to the conveying direction  105 . The conveyor roller  35  may be disposed above the following rollers  36 . The conveyor roller  35  and the following rollers  36  may be a roller pair. 
     As depicted in  FIG. 3 , the conveyor roller  35  may be a single roller that may extend in the right-left direction  103 . The conveyor roller  35  may be configured to be rotated by transmission of a drive force from the motor. 
     As depicted in  FIG. 2 , the following rollers  36  may be disposed below the conveyor roller  35 . The following rollers  36  may be configured to move substantially in the up-down direction  101 . The following rollers  36  may be spaced apart from each other in the right-left direction  103 . The following rollers  36  may be urged toward the conveyor roller  35  by an urging member such as a spring (not depicted). Therefore, a roller surface of each following roller  36  may be in contact with a roller surface of the conveyor roller  35 . When a sheet  100  enters between the conveyor roller  35  and the following rollers  36 , the following rollers  36  may be moved downward by the thickness of the sheet  100  against an urging force of the spring. Then, the sheet  100  may be nipped by the conveyor roller  35  and the following rollers  36 . In this state, when the conveyor roller  35  rotates, the sheet  100  may be conveyed in the conveying direction  105  in accordance with the rotation of the conveyor roller  35 . 
     As depicted in  FIG. 2 , a platen  50  may be disposed downstream of the conveyor roller  35  in the first conveying path  31  with respect to the conveying direction  105  and in the first conveying path  31  that may extend toward the front from the rear of the image recording apparatus  10 . The platen  50  may define a part of a lower side of the first conveying path  31 . 
     As depicted in  FIG. 3 , the platen  50  may have a plate-like shape that may extend in the right-left direction  103 . The platen  50  may be configured to hold a sheet  100  by its upper surface. The platen  50  may comprise a plurality of first ribs  51  and a plurality of second ribs  52 . The first ribs  51  and the second ribs  52  may be disposed on the upper surface of the platen  50 . The first ribs  51  and the second ribs  52  may be spaced apart from each other in the right-left direction  103 . 
     The first ribs  51  and the second ribs  52  may extend linearly along the conveying direction  105  across the upper surface of the platen  50 . The first ribs  51  and the second ribs  52  may be spaced apart from each other in the right-left direction  103 . The first ribs  51  may have a different function with respect to the sheet  100  than the second ribs  52 . Therefore, the locations of the first ribs  51  and the second ribs  52  on the upper surface of the platen  50  may be determined according to their respective functions. 
     The first ribs  51  may be configured to hold the sheet  100  by their upper ends. The second ribs  52  may prevent the sheet  100  from contacting the upper surface of the platen  50  when the sheet  100  moves toward the platen  50  as a result of swelling of the sheet  100  due to ink adhered to the sheet  100 . Therefore, the upper ends of the first ribs  51  may be located at a different level from upper ends of the second ribs  52  with respect to the up-down direction  101 . The upper ends of the first ribs  51  may be located higher than the upper ends of the second ribs  52  with respect to the up-down direction  101 . 
     The first ribs  51  may be disposed at respective positions in each of which a contact member  60  might not be disposed in the right-left direction  103 . The second ribs  52  may be disposed at respective positions in each of which a contact member  60  may be disposed in the right-left direction  103 . The first ribs  51  and the second ribs  52  might not need to be disposed alternately in the right-left direction  103 . For example, the upper ends of first ribs  51  may be located at respective different levels as long as the upper ends of the first ribs  51  are located higher than the upper ends of the second ribs  52  in the up-down direction  101 . In this embodiment, the sheet  100  may be conveyed in a state where the center line of the sheet  100  in the right-left direction  103  may be aligned with the center line of the platen  50  in the right-left direction  103 . Therefore, both of the first ribs  51  and the second ribs  52  may be symmetrically disposed about the center line of the platen  50  in the right-left direction  103 . 
     As depicted in  FIG. 2 , a carriage  48  may be disposed above the platen  50  while defining the first conveying path  31  therebetween. The carriage  48  may be supported by a guide rail (not depicted) and may be configured to move in the right-left direction  103  along the guide rail. The carriage  48  may be configured to move in the right-left direction  103  by transmission of a drive force from a motor (not depicted). 
     As depicted in  FIG. 4 , a recording head  46  may be mounted on the carriage  48 . The recording head  46  may be exposed in a lower surface of the carriage  48 . The recording head  46  may have a plurality of nozzles  47  arranged in rows extending along the front-rear direction  101  (e.g., the conveying direction  150 ). The nozzle rows may be provided for respective colors of ink and may be arranged side by side in the right-left direction  103 . Each nozzle  47  may be opened in a lower surface of the recording head  47  and configured to eject an ink droplet therefrom by vibration of a piezoelectric element and boiling of ink. 
     While the recording head  46  moves in the right-left direction  103  in accordance with the movement of the carriage  48 , the recording head  46  may eject ink droplets selectively from the nozzles  47 . The ejected ink droplets may land on the sheet  100  held by the platen  50 , and thus, an image may be recorded on the sheet  100 . 
     As depicted in  FIGS. 2 and 3 , the contact members  60  may be disposed near an upstream end of the platen  50  and downstream of the conveyor roller  35  in the conveying direction  105 . The contact members  60  may be spaced apart from each other in the right-left direction  103 . The contact members  60  may correspond to first upper contact portions. 
     A structure of the contact members  60  is now described below. In one or more examples, all of the contact members  60  may have the same configuration, and therefore, the description of one of the contact member  60  may apply to a remainder of the contact members  60 . The contact member  60  may comprise a fixing portion  61 , a curved portion  62 , and a contact portion  63 . The fixing portion  61  may be configured to be fixed to the guide rail for supporting the carriage  48 . The curved portion  62  may extend obliquely downward from the fixing portion  61  along the conveying direction  105 . A tip of the curved portion  62  may be located close to the vicinity of the upstream end of the platen  50 . The contact portion  63  may be configured to elastically deform upward because the contact member  60  may be made of, for example, synthetic resin. 
     The contact portion  63  may extend substantially parallel to the upper end of the second rib  52  of the platen  50  from an end of the curved portion  62  along the conveying direction  105 . The width of the contact portion  63  in the right-left direction  103  may be greater than the width of the second rib  52 . The contact portion  63  may have a plate-like shape and both ends of the contact portion  63  in the right-left direction  103  might not contact the first ribs  51  disposed on each side of the second rib  52  that the contact portion  63  may face. The contact portions  63  other than both endmost contact portions  63  in the right-left direction  105  may taper in a downstream conveying direction  105 . 
     The contact portion  63  may face a part of an upstream part of the second rib  52  in the conveying direction  105 . A lower surface of the contact portion  63  may be located higher than the upper end of the second rib  52  in the up-down direction  101  and may be located close to the upper ends of one second rib  52 . In addition, the lower surface of the contact portion  63  may be located lower than the upper end of the first rib  51  in the up-down direction  101 . Therefore, the lower surface of the contact portion  63  may be located closer to the upper surface of the platen  50  than the upper end of the first rib  51 . 
     As depicted in  FIGS. 2 and 3 , a plurality of first discharge rollers  37  and a plurality of spurs  38  may be disposed downstream of the platen  50  in the first conveying path  31  with respect to the conveying direction  105 . The first discharge rollers  37  may be disposed above the spurs  38 , respectively. One of the first discharge rollers  37  and a corresponding one of the spurs  38  may be a roller pair. 
     The first discharge rollers  37  may be disposed on a rotational shaft  39 . The rotational shaft  39  may extend along the right-left direction  103 . The rotational shaft  39  may be configured to be rotated by transmission of a drive force from the motor (not depicted). The first discharge rollers  37  may be spaced apart from each other in the right-left direction  103 . The first discharge rollers  37  may be configured to be rotated simultaneously by rotation of the shaft  39 . The first discharge rollers  37  may be disposed at respective positions corresponding to the respective first ribs  51  with respect to right-left direction  103 . 
     The spurs  38  may be disposed above the respective first discharge rollers  37 . The spurs  38  may be configured to move in substantially the up-down direction  101 . The spurs  38  may be spaced apart from each other in the right-left direction  103 . Each spur  38  may be disposed on a shaft (not depicted) that may extend along the right-left direction  103 . For example, the shaft of the spur  38  may be a coil spring. The spurs  38  may be supported by the coil springs, respectively, while being in contact with roller surfaces of the first discharge rollers  37 , respectively. When a sheet  100  enters between the first discharge rollers  37  and the spurs  38 , the spurs  38  may be moved while elastically deforming their shafts upward by the thickness of the sheet  100 . Therefore, the sheet  100  may be nipped by the first discharge rollers  37  and the spurs  38 . In this state, as the first discharge rollers  37  rotate, the sheet  100  may be conveyed in the conveying direction  105  in accordance with the rotation of the first discharge rollers  37 . A contact point of each pair of first discharge roller  37  and spur  38  may be located at the same or substantially the same level as the upper ends of the first ribs  51  with respect to the up-down direction  101 . 
     As depicted in  FIGS. 2 and 3 , the spurs  82  and the spurs  83  may be disposed downstream of the first discharge roller  37  in first conveying path  31  with respect to the conveying direction  105 . One of spurs  82  and one of spurs  83  may be arranged in each row in the conveying direction  105 . The rows each including one of spurs  82  and one of spurs  83  may be arranged along the right-left direction  103  and located at respective positions corresponding to the respective contact members  60 . The spurs  82  and the spurs  83  may correspond to second upper contact portions. 
     The spurs  82  and the spurs  83  may be configured to move in substantially the up-down direction  101 . Each of the spurs  82 ,  83  may be disposed on a shaft (not depicted) that may extend along the right-left direction  103 . For example, the shaft of each of the spurs  82 ,  83  may be a coil spring. With this configuration, each of the spurs  82 ,  83  may be configured to move in the up-down direction  101  by an amount of elastic deformation of the corresponding coil spring. Lowest ends of the spurs  82 ,  83  may be located at the same or substantially the same positions as the lower surfaces of the contact portions  63  of the corresponding contact portions  60 , respectively, in the up-down direction  101 . For example, projecting ends of the spurs  82 ,  83  projecting toward the first conveying path  31  may be located closer to the platen  50  than the roller surface of the first discharge rollers  37  projecting toward the first conveying path  31 . 
     As depicted in  FIGS. 2 and 3 , a plurality of second discharge rollers  55  and a plurality of spurs  56  may be disposed downstream of the spurs  83  in the first conveying path  31  with respect to the conveying direction  105 . The second discharge rollers  55  may be disposed below the respective spurs  56 . The second discharge rollers  55  and the spurs  56  may be a roller pair. 
     The second discharge rollers  55  may be disposed on a rotational shaft  57 . The rotational shaft  57  may extend along the right-left direction  103 . The rotating shaft  57  may be configured to be rotated by transmission of a drive force from the motor (not depicted). The second discharge rollers  55  may be spaced apart from each other in the right-left direction  103 . The second discharge rollers  55  may be configured to be rotated simultaneously by rotation of the shaft  57 . The second discharge rollers  55  may be disposed at respective positions corresponding to the respective first ribs  51  with respect to the right-left direction  103 . 
     The spurs  56  may be disposed above the respective second discharge rollers  55 . The spurs  56  may be configured to move in the up-down direction  101 . The spurs  56  may be spaced apart from each other in the right-left direction  103 . Each of the spurs  56  may be disposed on a shaft  58  that may extend along the right-left direction  103 . For example, the shaft of each of the spurs  56  may be a coil spring. The spurs  56  may be supported by the respective shafts  58  in a state where the spurs  56  may be in contact with the roller surfaces of the second discharge rollers  55 , respectively. Axes of the shafts  58  may be located upstream of an axis of each shaft  57  of the second discharge rollers  55  in the conveying direction  105 . 
     When a sheet  100  enters between the second discharge rollers  55  and the spurs  56 , the spurs  56  may be moved by the thickness of the sheet  100  while elastically deforming their shafts  58  upward. Therefore, the sheet  100  may be nipped by the second discharge rollers  55  and the spurs  56 . In this state, as the first discharge rollers  55  rotate, the sheet  100  may be conveyed in the conveying direction  105  by the rotation of the first discharge rollers  55 . A contact point of each pair of the first discharge roller  55  and the spur  56  may be located at the same or substantially the same positions as the upper ends of the first ribs  51  with respect to the up-down direction  101 . 
     As depicted in  FIGS. 2 ,  3 , and  9 , a plurality of spurs  84  may be disposed downstream of the second discharge rollers  55  in first conveying path  31  with respect to the conveying direction  105 . The spurs  84  may be spaced apart from each other in the right-left direction  103 . However, no spur  84  may be disposed at a position corresponding to each of the endmost contact members  60  of the plurality of contact members  60  in the right-left direction  103 . The spurs  84  may correspond to third upper contact portions. In  FIG. 2 , the spurs  84  may be disposed at the same position as the spurs  56  with respect to the direction perpendicular to the drawing sheet. Therefore, the spurs  84  are not depicted in  FIG. 2 . 
     The spurs  84  may be configured to move in substantially the up-down direction  101 . Each of the spurs  84  may be disposed on a shaft (not depicted) that may extend along the right-left direction  103 . For example, the shaft of each spur  84  may be a coil spring. With this configuration, each of the spurs  84  may be configured to move in the up-down direction  101  by an amount of elastic deformation of the corresponding shaft. Lowest ends of the spurs  84  may be located at the same or substantially the same positions as the lower surfaces of the contact portions  63  of the contact portions  60 , respectively, in the up-down direction  101 . Projecting ends of the spurs  84  projecting toward the first conveying path  31  may be located at the same or substantially the same positions as the roller surfaces of the second discharge rollers  55  protruding toward the first conveying path  31  in the front-rear direction  102 . 
     As depicted in  FIGS. 2 and 8 , a guide portion  72  may be disposed on each side of each second discharge roller  55  in the right-left direction  103 . The guide portions  72  may be configured to cover a peripheral surface of the shaft  57  of the second discharge rollers  55 . The guide portions  72  may be a part of the defining member  70  constituting a lower guide surface of the second conveying path  32 . The guide portions  72  may be engaged with the peripheral surface of the shaft  57 . The defining member  70  may be configured to pivot about the shaft  57  when the guide portions  72  turns around the shaft  57 . When the defining member  70  pivots, the lower side of the second conveying path  32  may be opened. For example, the defining member  70  may be pivoted when a sheet  100 , jammed in the second conveying path  32 , is removed. 
     Peripheral surfaces of the guide portions  72  may be located closer to the peripheral surface of the shaft  57  than the roller surfaces of the second discharge rollers  55 . For example, the guide portions  72  might not protrude more outwardly in a radial direction of the shaft  57  than the roller surfaces of the second discharge rollers  55 . The peripheral surfaces of the guide portions  72  may be configured to direct a leading edge of a sheet  100  that is to be conveyed to the second discharge rollers  55  in the conveying direction  105  to be nipped between the second discharge rollers  55  and the spurs  56 . 
     As depicted in  FIGS. 1 and 2 , a sheet discharge tray  23  may be disposed downstream of the second discharge rollers  55  in the conveying direction  105 . The sheet discharge tray  23  may be configured to support a sheet  100  discharged from the first conveying path  31 . An upper surface of the sheet discharge tray  23  may be configured to support the sheet  100 . 
     The sheet discharge tray  23  may comprise tray members  24 ,  25 , and  26 . The tray members  24 ,  25 , and  26  may be united such that the tray members  24 ,  25 , and  26  may be slidable independently. The tray members  24 ,  25 , and  26  may be disposed in this order from upstream in the conveying direction  105 . The width along the right-left direction  103  of the tray member  24  that may be disposed at a most-upstream position in the conveying direction  105  may be wider than the width along the right-left direction  103  of the tray member  25  that may be disposed downstream of the tray member  24  in the conveying direction  105 . The width along the right-left direction  103  of the tray member  25  may be wider than the width along the right-left direction  103  of the tray member  26  that may be disposed at a most-downstream position in the conveying direction  105 . Therefore, the width along the right-left direction  103  of the tray members  24 ,  25 , and  26  may become narrower along the conveying direction  105 . 
     As depicted in  FIGS. 1 and 2 , the display panel  16  may be disposed on the front of the housing  14 . Therefore, the display panel  16  may be located downstream of the second discharge rollers  55  in the conveying direction  105 . In addition, the display panel  16  may be disposed above the opening  15  of the housing  14 . Therefore, the display panel  16  may be located at a higher position than the second discharge rollers  55  in the up-down direction  101 . 
     As described above, the axes of the shafts  58  of the spurs  56  may be located upstream of the axis of the shaft  57  of the second discharge rollers  55  in the conveying direction  105 . Therefore, a tangent line  106  that may pass through the nip position between one second discharge roller  55  and one spur  56  and may be tangent to the roller surface of the second discharge roller  55  may extend obliquely upward in the conveying direction  105 . A sheet  100  to be discharged from the first conveying path  31  while being sandwiched between the second discharge rollers  55  and the spurs  56  may be discharged along the tangent line  106  if the sheet  100  is not deformed, e.g., like a rigid body. 
     However, sheets of various types (including the above-described recording sheet) on which image recording is to be performed by the printer unit  11 , may have flexibility such that the sheets may be bent along the curved section of the first conveying path  31 . Therefore, the sheets of various types to be discharged from the first conveying path  31  while being sandwiched between the second discharge rollers  55  and the spurs  56  may sag downward from the tangent line  106 . 
     A lower end of the display panel  16  disposed on the front of the housing  14  may be located higher than the tangent line  106 . Therefore, the various sheets might not contact the lower end of the display panel  16  when the sheets are discharged from the first conveying path  31 . 
     In addition, as depicted in  FIGS. 1 and 5 , the gripping portion  17  (indicated by a dashed line in  FIG. 5 ) may be disposed at the lower end of the display panel  16 . The gripping portion  17  may be located outside of both ends of the narrowest tray member  26  in the right-left direction  103  of the sheet discharge tray  23 . 
     Hereinafter, an operation of the image recording apparatus  10  is now described. The printer unit  11  may be configured to operate upon receipt of an instruction of image recording. The feed roller  43 , the conveyor roller  35 , the first discharge rollers  37 , the second discharge rollers  55 , and the carriage  48  may be operated at a predetermined timing by which the motor may be driven at a predetermined timing in the printer unit  11 . 
     The feed roller  43  may feed an uppermost sheet of the one or more sheets placed on the sheet feed tray  20  in the sheet feeding direction  104  by the rotation of the feed roller  43 . The inclined wall  22  may contact a leading edge of the fed sheet and direct the sheet  100  upward to allow the sheet to enter the first conveying path  31 . Then, the leading edge of the sheet  100  entered the first conveying path  31  may reach the conveyor roller  35  and the following rollers  36 . At that time, the conveyor roller  35  and the following rollers  36  may nip the leading end of the sheet  100  and then may convey the sheet  100  to a position upstream of the platen  50 . 
     At the position upstream of the platen  50  in the conveying direction  50 , the first ribs  51  of the platen  50  may hold the sheet  100  from below and the contact portions  63  of the contact members  60  may press an upper surface of the sheet  100 . For example, the first ribs  51  and the contact portions  63  may nip the leading edge of the sheet  100  therebetween. 
     As depicted in  FIG. 6 , the upper ends of the first ribs  51  may be located higher than the lower surfaces of the contact portions  63  of the contact members  60  in the up-down direction  101 . In addition, one of the first ribs  51  may be disposed between adjacent ones of the contact portions  60  in the right-left direction  103 . The contact portions  60  might not be disposed above any of the first ribs  51  in the up-down direction  101 . Therefore, the sheet  100  may be formed into a corrugated shape, in which the sheet  100  may have ridge portions that may be held by the first ribs  51  and groove portions that may be depressed by the contact portions  63 . In this embodiment, the sheet  100  may have a maximum width on which the printer unit  11  may be able to perform image recording in the right-left direction  103 . Thus, the endmost contact portions  63  in the right-left direction  103  may press side edges of the sheet  100  in the right-left direction  103  from above. 
     For example, when a sheet  100  having relatively high stiffness, such as a thick paper, is conveyed, the contact portions  63  may be slightly moved upward in the up-down direction  101  when the curved portions  62  of the contact members  60  may be deformed elastically. A deformation amount of the curved portions  62  may be determined such that the lower surfaces of contact portions  63  might not be located at respective positions higher than the upper ends of the first ribs  51  when the curved portions  62  may be deformed elastically. 
     After the leading edge of the sheet  100  passes below the contact portions  63 , the contact portions  63  might not press the groove portions formed in the leading edge of the sheet  100  from above and the first ribs  61  of the platen  50  may hold the ridge portions formed in the leading edge of the sheet  100  held on the platen  50 . For example, in the sheet  100  such a recording sheet, the pressing of the sheet  100  by the contact portions  63  to form a corrugated shape in the sheet  100  may have influence on a downstream part of the sheet  100  in the conveying direction  105 . 
     When the leading edge of the sheet  100  reaches under the recording head  46 , the conveyor roller  35  may be allowed to stop rotating to stop the conveyance of the sheet  100 . While the conveyance of the sheet  100  is stopped, the carriage  48  may be driven to move along the right-left direction  103  and the recording head  47 , that may move together with the carriage  48  along the right-left direction  103 , may selectively eject ink droplets from the nozzles  47 . The ink droplets ejected from the nozzles  47  may be adhered onto the sheet  100 . Then, after the conveyor roller  35  may be rotated by a predetermined amount corresponding to a line feed to further convey the sheet  100  in the conveying direction  105 . Subsequently, the conveyor roller  35  may be allowed to stop rotating again. The image recording apparatus  10  may record a desired image onto the sheet  100  by alternately performing a line feed and the movement of the recording head  46  (e.g., an intermittent conveyance). 
     For example, a sheet  100  whose paper grain direction is parallel to the right-left direction  103  may tend to curl along the conveying direction  105  by adhesion of ink droplets. However, the corrugation pattern formed in the sheet  100  in the right-left direction  103  may increase the stiffness of the sheet  100  in the conveying direction  105  and reduce an occurrence of the curling in the sheet  100  when ink droplets are adhered to the sheet  100 . 
     By the intermittent conveyance of the sheet  100 , the leading edge of the sheet  100  may pass the platen  50  and then reach the first discharge rollers  37  and the spurs  38 . The pairs of first discharge roller  37  and spur  38  may be disposed at respective positions corresponding to the first ribs  51  in the right-left direction  103 . Therefore, the pairs of first discharge roller  37  and spur  38  may nip the respective ridge portions formed in the corrugated sheet  100 . After that, the first discharge rollers  37  and the spurs  38  may further convey the sheet  100  in the conveying direction  105  by the rotation of the first discharge rollers  37 . The rotation of the first discharge rollers  37  may be synchronized with the rotation of the conveyor roller  35 . 
     As depicted in  FIGS. 7 and 9 , lower ends of the spurs  82 ,  83  may be located lower than the nip points between the first discharge rollers  37  and spurs  38  in the up-down direction  101 . One pair of the spur  82  and the spur  83  may be disposed between each pair of the first discharge roller  37  and the spur  38  in the right-left direction  103 , and the first discharge rollers  37  and the spurs  38  might not be disposed under any pair of the spur  82  and the spur  83  in the up-down direction  101 . With this configuration, the sheet  100  may be formed into the corrugated shape, in which the sheet  100  may have ridge portions that may be nipped by the first discharge rollers  37  and the spurs  38  and groove portions that may be depressed by the spurs  82  and  83 . In this embodiment, the sheet  100  may have a maximum width on which the printer unit  11  may be able to perform image recording in the right-left direction  103 . Thus, endmost pairs of the spur  82  and the spur  83  may press the side edges of the sheet  100  in the right-left direction  103  from above. 
     The ridge portions formed in an upstream part of the sheet  100  may be held by the respective first ribs  51  and the groove portions formed in the upstream part of the sheet  100  may be depressed by the respective contact portions  63  in the conveying direction  105 . Then, the ridge portions formed in a downstream part of the sheet  100  may be nipped by the first discharge rollers  37  and the spurs  38  and the groove portions formed in the downstream part of the sheet  100  may be depressed by the spurs  82  and  83 . Therefore, the sheet  100  may be corrugated on both sides of the platen  50  in the conveying direction  105 . 
     Downstream from spurs  82  and  83  and first discharge rollers  37 , the leading edge of the sheet  100  may reach the second discharge rollers  55  and the spurs  56  by which the first discharge rollers  37  and the spurs  38  may further convey the sheet  100  in the conveying direction  105 . The second discharge rollers  55  and the spurs  56  may be disposed at the respective positions corresponding to the (e.g., aligned with) respective first ribs  51  in the right-left direction  103 . Therefore, the second discharge rollers  55  and the spurs  56  may nip the ridge portions of the corrugated sheet  100 . Subsequently, the second discharge rollers  55  and the spurs  56  may further convey the sheet  100  in the conveying direction  105  by the rotation of the second discharge rollers  55 . The rotation of the second discharge rollers  55  may be synchronized with the rotation of the conveyor roller  35 . 
     As depicted in  FIGS. 8 and 9 , lower ends of the spurs  84  may be located lower than the nip points between the second discharge rollers  55  and the spurs  56  in the up-down direction  101 . Additionally, one spur  84  may be disposed between each pair of the second discharge roller  37  and the spur  38  in the right-left direction  103 , and the second discharge rollers  55  and the spurs  56  might not be disposed under any spur  84  in the up-down direction  101 . The upper guide surfaces of the guide portions  72  may be located lower than the nip points between the second discharge rollers  55  and the spurs  56  in the up-down direction  101 . Therefore, the sheet  100  may be formed into the corrugated shape (or the corrugated shape of the sheet  100  may be maintained), in which the sheet  100  may have ridge portions that may be nipped by the second discharge rollers  55  and the spurs  56  and groove portions that may be depressed by the spurs  84  and may be guided upward by the guide portions  72  such that the groove portions might not come into contact with the shaft  57 . 
     In this embodiment, the sheet  100  may have a maximum width on which the printer unit  11  may be able to perform image recording in the right-left direction  103 . The spurs  84  might not be disposed at the respective positions facing both side edges of the maximum-sized sheet  100  in the right-left direction  103 . Therefore, the groove portions formed on the both side edges of the sheet  100  in the right-left direction  103  may be guided by the guide portions  72  to prevent the sheet  100  from contacting the shaft  57  and might not be pressed by the spurs  84 . 
     The ridge portions of the sheet  100  may be nipped by the second discharge rollers  55  and the spurs  56  and the groove portions of the sheet  100  may be depressed by the spurs  84  from above. Therefore, the sheet  100  may be formed into a corrugated shape. The axes of the shafts  58  of the spurs  56  may be located upstream of the axis of the shaft  57  of the second discharge rollers  55 . Therefore, the second discharge rollers  55  and the spurs  56  may discharge the sheet  100  onto the sheet discharge tray  23  along the tangent line  106  by nipping the sheet  100  therebetween. 
     The both ends of the tray members  25  and  26  in the right-left direction  103  may be located closer to the center line of the sheet discharge tray  23  than the both side edges of the sheet  100  in the right-left direction  103 . Therefore, both ends of the tray members  25  and  26  might not contact with the both side edges of the sheet  100  in the right-left direction  103 . Further, the second discharge rollers  56  and the spurs  55  may discharge the corrugated sheet  100  obliquely upward along the tangent line  106 . Thus, the leading edge of sheet  100  might not sag downward toward the tray member  24  until a most part of the sheet  100  passes through the nip points between the second discharge rollers  56  and the spurs  55 . Therefore, the tray member  24  might not contact the both side edges of the sheet in the right-left direction  103 . 
     When the inkjet recording apparatus  10  performs double-sided printing, the second discharge rollers  55  may be stopped (e.g., temporarily) immediately before the trailing edge of the sheet  100  (and after the trailing edge of the sheet  100  has passed the spurs  82  and  83 ), on which an image has been recorded on a first surface of the sheet  100 , passes the nip points between the second discharge rollers  55  and the spurs  56 . Then, the second discharge rollers  55  may be rotated in the reverse direction. Thus, the sheet  100  may be conveyed in a direction opposite to the conveying direction  105  and enter the second conveying path  32  from the first conveying path  31 . In other embodiments, for example, a guide flap may be disposed on a junction of the first conveying path  31  and the second conveying path  32 . The guide flap may be configured to guide the sheet  100  smoothly to the second conveying path  32  from the first conveying path  31 . 
     The sheet  100  that enters the second conveying path  32  may enter again the curved section of the first conveying path  31  while the first surface on which the image has been recorded is curved inward. Then, the image recording apparatus  10  may record an image on a second surface of the sheet  100  in a similar manner that the image recording apparatus  10  records an image on the first surface of the sheet  100 . 
     According to the illustrative embodiment, no spur  84  may be disposed at the positions corresponding to the endmost ones of the contact members  60  in the right-left direction  103 . Therefore, the groove portions of the both side edges of corrugated sheet  100  in the right-left direction  103  might not be depressed downward by the spurs  84 . Thus, an occurrence the side edges of the corrugated sheet  100  being caught on a holding surface of the sheet discharge tray  23  or the corrugated sheet  100  pushing the sheet  100  held on the sheet discharge tray  23  out of the sheet discharge tray  23  may be reduced. 
     According to the illustrative embodiment, the axes of the shafts  58  of the spurs  56  may be located upstream of the axis of the shaft  57  of the second discharge rollers  55 . Therefore, the second discharge rollers  56  and the spurs  55  may discharge the sheet  100  onto the sheet discharge tray  23  along the tangent line  106  by nipping the sheet  100  therebetween. Thus, an occurrence of a problem that the leading edge of the sheet  100  may be caught on the holding surface of the sheet discharge tray  23  may be reduced. 
     According to the illustrative embodiment, the guide portions  72  may be disposed outside of both endmost rollers of the second discharge rollers  55  in the right-left direction  103  and may cover the shaft  57 . Thus, the groove portions of the side edges of the corrugated sheet  100  in the right-left direction  103  may be smoothly guided to the nip points between the second discharge rollers  55  and the spurs  56  by the guide portions  72 . 
     According to the illustrative embodiment, the width of the sheet discharge tray  23  in the right-left direction  103  may become narrower along the conveying direction  105 . Therefore, the sheet discharge tray  23  may be configured to hold the sheet  100  while the holding surface of the sheet discharge tray  23  is not present at positions corresponding to the side edges of a downstream end of the corrugated sheet  100 . This configuration may reduce an occurrence of floating of the sheet  100  from the holding surface of the sheet discharge tray  23 . Therefore, the sheet discharge tray  23  may hold a large number of sheets  100 . 
     According to the illustrative embodiment, the lower end of the display panel  16  may be located higher than the tangent line  106 . Thus, an occurrence a problem that the leading edge of the sheet  100  being discharged and nipped by the second discharge rollers  56  and the spurs  55  may come into contact with the display panel  16  may be reduced. 
     According to the illustrative embodiment, the grip portion  17  of the display panel  16  may be located outside of the both ends of the tray member  26  in the right-left direction  103 . Thus, a user can operate the grip portion  17  without interfere in the sheets  100 , although a sheet  100  having a width smaller than the width of the tray member  26  may be held by the feed discharge tray  23 , a user can without interfering with the sheet  100 . 
     A variation of the illustrative embodiment is now described. In the above-described illustrative embodiment, a straight section of the first conveying path  31  may extend along the front-rear direction  120  and the right-left direction  103  and substantially perpendicular to the up-down direction  101 . Therefore, the positional relationship between the upper ends of the first ribs  51  and the upper ends of the second ribs  52  of the platen  50  and the positional relationship between the upper ends of the first ribs  51  and the lower surfaces of the contact portions  63  of the contact members  60  may be described with the word “higher” or “lower” with respect to the up-down direction. The area in which the platen  50 , the contact members  60 , the first discharge rollers  37 , the spurs  38 ,  56 ,  82 ,  83 ,  84 , and the second discharge rollers  55  may be disposed in the first conveying path  31  might not necessarily extend perpendicularly to the up-down direction. For example, the first conveying path  31  may extend obliquely upward or obliquely downward. In this case, the positional relationship between the upper ends of the first ribs  51  and the upper ends of the second ribs  52  of the platen  50  and the positional relationship between the upper ends of the first ribs  51  and the lower surfaces of the contact portions  63  of the contact members  60  may be described according to various directional relationships depending on the configuration (e.g., direction, angle, etc.) of the first conveying path  31 . 
     In the above-described illustrative embodiment, the recording head  46  may be mounted on the carriage  48  and configured to move in the right-left direction  103 . Nevertheless, in other embodiments, for example, a recording head may have nozzle rows defined across an area that may correspond to the width of the sheet  100  in the right-left direction  103  and be configured to eject ink droplets across the width of the sheet  100  in the right-left direction  103  without mount in the right-left direction  103 . 
     Although specific examples of carrying out the invention have been described, those skilled in the art will appreciate that there are numerous variations and permutations of the above-described systems and methods that are contained within the spirit and scope of the invention as set forth in the appended claims. Additionally, numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure.