Patent Publication Number: US-2021179375-A1

Title: Conveyance apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims priority from Japanese Patent Application No. 2019-226112 filed on Dec. 16, 2019, the disclosure of which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     The present disclosure relates to a conveyance apparatus (conveyor) configured to convey a sheet pulled out from a roll body. 
     In an ink-jet type image recording apparatus, a conveyance roller pair rotates while nipping a sheet pulled out from a roll body, thereby conveying the sheet in a conveyance orientation. A recording head faces a platen at a downstream side of the conveyance roller pair in the conveyance orientation. The recording head discharges ink to the sheet supported by the platen (see, for example, International Publication No. WO2014/156122). 
     SUMMARY 
     The roll body may be a perforated roll body in which a sheet with small holes (hereinafter also referred to as “perforations”) that are continuously formed in a width direction of the sheet is wound around an axial core. The sheet with small holes is easily cut at a predefined position after an image is recorded by an image recording apparatus. An example of the perforated roll body is a roll body in which a long separator is wound around the axial core. The separator has perforations along an axial core direction with an interval from a front end in a roll winding direction of the separator. In the separator, a label on which an image is to be recorded is attached to a portion between two perforations adjacent to each other in the roll winding direction. 
     In the image recording apparatus, when image recording is performed on the perforated roll body, the front end of the separator may be conveyed only by conveyance force from a conveyance roller positioned upstream of the front end in the conveyance orientation. In such a situation, when a front end of the sheet is caught by a guide or the like disposed downstream of the conveyance roller, the separator may buckle at a perforated portion and jam may be caused. 
     In view of the above, an object of the present disclosure is to provide a conveyance apparatus that is capable of inhibiting buckling of a sheet. 
     A conveyance apparatus of the present disclosure includes: a holder configured to hold a roll body so that the roll body is rotatable around a first axis; a first conveyance member configured to convey a sheet pulled out of the roll body in a conveyance orientation crossing an axis direction in which the first axis extends; a support member which is arranged downstream of the first conveyance member in the conveyance orientation and which has a support surface facing a first surface of the sheet; a recording head facing the support surface in a crossing direction crossing the axis direction and the conveyance orientation; and a first guide member which is arranged between the first conveyance member and the support member in the conveyance orientation, and which has a first guide surface configured to guide the first surface of the sheet and a second guide surface configured to guide a second surface of the sheet, the first and second surfaces facing opposite orientations to each other, wherein the first guide surface and the second guide surface are configured to guide the sheet so that the sheet has a curved shape in a cross-section orthogonal to the conveyance orientation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  schematically depicts a configuration of an image recording apparatus  100  according to an embodiment, and  FIG. 1B  is a perspective view of a roll body  50  used in the image recording apparatus  100 . 
         FIG. 2  schematically depicts the image recording apparatus  100  when seeing, from the right, a longitudinal section (vertical section) taken along a two-dot chain line II-II in  FIG. 1A . 
         FIG. 3A  schematically depicts the image recording apparatus  100  when seeing, from above, a cross section (transverse section) taken along a two-dot chain line Ina-Ina in  FIG. 1A , and  FIG. 3B  depicts a conveyance belt  37 A and a sheet support member  37 B when seen from above and a block configuration of main parts of the image recording apparatus  100 . 
         FIG. 4A  schematically depicts a guide unit  47  depicted in  FIGS. 2 and 3  when seen from above, and  FIG. 4B  schematically depicts the guide unit  47  when seeing, from the front, a longitudinal section taken along a two-dot chain line IVb-IVb in  FIG. 4A . 
         FIG. 5A  is a schematic view of a first modified example of the guide unit  47 , and  FIG. 5B  is a schematic view of a second modified example of the guide unit  47 . 
         FIG. 6  is a schematic view of a third modified example of the guide unit  47 . 
         FIG. 7A  is a schematic view of a fourth modified example of the guide unit  47  when seen from above,  FIG. 7B  schematically depicts a longitudinal section taken along a two-dot chain line VIIb-VIIb in  FIG. 7A  when seen from the right, and  FIG. 7C  schematically depicts a longitudinal section taken along a two-dot chain line VIIc-VIIc in  FIG. 7A  when seen from the right. 
     
    
    
     EMBODIMENTS 
     An image recording apparatus  100  according to an embodiment of the present disclosure is explained below. The embodiment described below is merely an example of the present invention, and it goes without saying that the embodiment of the present invention may be appropriately changed in a range that does not alter the gist or characteristics of the present invention. In the following explanation, advancement (movement) from a starting point to an end point of an arrow is expressed as an orientation, and coming and going on a line connecting the starting point and the end point of the arrow is expressed as a direction. Further, in the following explanation, an up-down direction  7  is defined by using a state where the image recording apparatus  100  is usably installed (a state depicted in  FIG. 1A ) as a reference, a front-rear direction  8  is defined with a side on which a discharge opening  13  is provided being designated as the frontward side (front surface or front side), and a left-right direction  9  is defined when seeing the image recording apparatus  100  from the frontward side (front surface). 
     &lt;External Configuration of Image Recording Apparatus  100 &gt; 
     As depicted in  FIG. 1A , the image recording apparatus  100  records an image on a label  53  or the like of a roll body  50  in accordance with an ink-jet recording system. The image recording apparatus  100  is used by being placed on a table, a floor, a rack, or the like. 
     A casing  30  has a substantially rectangular parallelepiped shape. As depicted in  FIG. 1A  and  FIG. 2 , the casing  30  includes a lower casing  32  and an upper casing  31 . 
     The lower casing  32  has a bottom surface  32 D, a front surface  32 F, a rear surface  32 B, a left surface  32 L, and a right surface  32 R, thus partitioning an inner space  32 A of the lower housing  32  from the outside, as depicted in  FIG. 2 . The inner space  32 A is an opening opened upward. 
     As depicted in  FIG. 1A , the upper casing  31  has an upper surface  31 U, a front surface  31 F, a rear surface  31 B, a left surface  31 L, and a right surface  31 R, thus partitioning an inner space  31 A of the upper casing  31  (see  FIG. 2 ) from the outside. The upper casing  31  pivots between a closed position where the inner spaces  31 A and  32 A are shielded from the outside and an open position where the inner spaces  31 A and  32 A are exposed to the outside. 
     As depicted in  FIG. 1A , the discharge port  33  is positioned close to an upper end of the front surface  32 F. The discharge opening  33 , which has a slit-like shape, is longer in the left-right direction  9  than a width of a separator  52  of the roll body  50 . The image recording apparatus  100  discharges the label  53  for which image recording has been performed together with the separator  52  from the discharge opening  33  to the outside. 
     &lt;Internal Configuration of Image Recording Apparatus  100 &gt; 
     As depicted in  FIG. 2 , a holder  35 , a tensioner  45 , a conveyance roller pair  36 , a guide unit  47 , a conveyance belt  37 A, a sheet support member  37 B, a recording head  38 , a conveyance roller pair  40 , a tank  42 , and a controller  41  (see  FIG. 3B ) are arranged in the inner spaces  31 A and  32 A. A maintenance unit, such as a cap covering a nozzle surface  38 B of the recording head  38  and a wiper wiping off the nozzle surface  38 B, and the like are arranged in the inner spaces  31 A and  32 A. However, since the maintenance unit is not a main part (essential part) of this embodiment, the explanation and illustration thereof are omitted. A combination of the conveyance roller pair  36 , the guide unit  47 , the conveyance belt  37 A, and the sheet support member  37 B is an exemplary conveyance apparatus (conveyor). 
     The holder  35  is positioned in the vicinity of a lower rear corner of the inner space  32 A (see  FIG. 2 ). In the inner space  32 A, a support frame  34  is fixedly positioned apart from and on the left of the right surface  32 R, as depicted in  FIG. 3A . The support frame  34  is spaced leftward from the right surface  32 R by a distance exceeding a width of the roll body  50 . The support frame  34  extends in the up-down direction  7  and the front-rear direction  8 . A shaft  35 A of the holder  35  extends rightward from the support frame  34  to a slightly left position with respect to a cover  35 C (see  FIG. 1A ) positioned in the right surface  32 R. 
     The roll body  50  depicted in  FIG. 1B  is installed in the holder  35 . The roll body  50  includes a core tube  51 , the long separator  52 , and the labels  53 . The labels  53  are paper or films. A combination of the labels  53  and the separator  52  is an exemplary sheet, which is wound around the core tube  51  about an axial core (axis)  51 A of the core tube  51 . An axis direction (i.e., left-right direction  9 ) in which the axial core  51 A extends is also referred to as a width direction of the roll body  50 . The axial core  51 A is an example of a first axis. In the separator  52 , small holes  52 B each having a slit shape are arranged parallelly to the axial core  51 A with an interval from a front end  52 A of the separator  52 . The small holes  52 B are so-called perforations, and hereinafter also referred to as a small hole row  52 B. The separator  52  has a first surface  52 C and a second surface  52 D. The second surface  52 D is a surface in an outward orientation  4 A included in a radial direction  4  of the axial core  51 A and away from the axial core  51 A. Each label  53  is put on an area of the second surface  52 D between two small hole rows  52 B adjacent to each other in a circumferential direction  5  of the axial core  51 A. The first surface  52 C is a surface of the separator  52  in an inward orientation  4 B, which is opposite to the outward orientation  4 A. 
     In the roll body  50 , a long sheet on which image recording is to be performed may be wound around the core tube. In this case, the long sheet is formed having the small hole rows  52 B with an interval from a front end of the long sheet. An image is to be recorded in the area of the long sheet between the small hole rows  52 B adjacent to each other in the circumferential direction  5 . Further, in the roll body  50 , a long sheet having no small hole row  52 B may be wound around the core tube. The roll body  50  may not include the core tube. So-called fanfold paper may be accommodated in the internal space  32 A. 
     As depicted in  FIG. 3A , the holder  35  holds the roll body  50  so that the axial core  51 A of the roll body  50  extends in the left-right direction  9  and the roll body  50  is rotatable about the axial core. Further, the holder  35  holds the roll body  50  so that the first surface  52 C of the separator  52  faces the axial core  51 A. 
     Specifically, the holder  35  sandwiches and holds the roll body  50  by two guide members  35 B positioned at left and right ends of the shaft  35 A. Each of the two guide members  35 B has a flange-like shape. The two guide members  35 B are an example of a third guide member and an example of a fourth guide member. Two guide surfaces  35 D (an example of a third guide surface and an example of a fourth guide surface) of the two guide members  35 B facing the inside are brought into contact with a first end and a second end in the left-right direction  9  (i.e., axis direction) of the separator  52 . 
     The two guide members  35 B are movable in the left-right direction  9  by a rack-pinion mechanism (not depicted). Specifically, one of the two guide members  35 B closer to the cover  35 C is linked with the other of the two guide members  35 B farther from the cover  35 C. When one of the two guide members  35 B closer to the cover  35 C moves to a first side in the left-right direction  9 , the other of the two guide members  35 B farther from the cover  35 C moves to a second side in the left-right direction  9  by the same distance. A movable range in the left-right direction  9  of the two guide members  35 B is determined in advance. That is, an interval in the left-right direction  9  between the two guide surfaces  35 D takes a value from a smallest interval to a largest interval. The smallest interval is a smallest width of the roll body  50  that can be used in the image recording apparatus  100 . The largest interval is a largest width of the roll body  50  that can be used in the image recording apparatus  100 . When the roll body  50  is installed in the holder  35 , the first surface  52 C of the separator  52  (see  FIG. 1B ) faces the inward orientation  4 B of the radial direction  4 . The center in the width direction of the separator  52  is positioned at a center plane in the left-right direction  9  of a conveyance path  43  (hereinafter also referred to as a “sheet passing center plane C” (see  FIG. 3 )). The sheet passing center plane C is an example of a reference plane. The holder  35  rotates by receiving rotation from a motor (not depicted), thus rotating the roll body  50 . 
     As depicted in  FIG. 1 , the cover  35 C is positioned in the right surface  32 R of the lower casing  32  for replacement of the roll body  50  and the like. The cover  35 C moves between a closed position where the holder  35  and the roll body  50  are shielded from the outside (see  FIG. 1A ) and an open position (not depicted) where those are exposed to the outside. 
     As depicted in  FIG. 2 , the tensioner  45  is an example of a second guide member. The tensioner  45  is positioned above the roll body  50  in the inner space  32 A. The separator  52  pulled out from the holder  35  is hung on a curved surface that is an outer circumferential surface of the tensioner  45 . The tensioner  45  curves the separator  52  toward the conveyance roller pair  36  in a state where the curved surface is brought into contact with the first surface  52 C of the separator  52 . Further, the tensioner  45  urges the separator  52  on the curved surface rearward to apply tension to the separator  52 . 
     The conveyance roller pair  36  (an example of a first conveyance member) is positioned at the front side of the tensioner  45 . In the conveyance roller pair  36 , a conveyance roller  36 A comes into contact with a pinch roller  36 B at substantially the same position in the up-down direction  7  as an upper end of the tensioner  45  to form a nip D. The conveyance roller pair  40  is positioned at the front side of the conveyance roller pair  36 . In the conveyance roller pair  40 , a conveyance roller  40 A comes into contact with a pinch roller  40 B at substantially the same position in the up-down direction  7  as the nip D. The conveyance rollers  36 A and  40 A rotate by receiving driving force of a motor (not depicted). This allows the conveyance roller pair  36  to convey the separator  52  extending frontward from the tensioner  45  in a conveyance orientation  8 A (specifically, frontward). The conveyance roller pair  40  conveys the separator  52  conveyed by the conveyance roller pair  36  in the conveyance orientation  8 A, and discharges the separator  52  through the discharge opening  33 . The rotation of the conveyance roller pairs  36  and  40  pulls out the separator  52  from the roller body  50  installed in the holder  35 . 
     As depicted in  FIG. 2 , the inner space  32 A is formed having the conveyance path  43  ranging from the nip D to the discharge opening  33 . The conveyance path  43  extends substantially linearly along the conveyance orientation  8 A. The conveyance path  43  is a space through which the separator  52  with the labels  53  affixed thereto can pass. A width of the conveyance path  43  is the same as or slightly larger than a maximum width of the roll body  50  (i.e., a maximum width of separator  52 ). The conveyance path  43  is defined by the guide unit  47 , the recording head  38 , the conveyance belt  37 A, the sheet support member  37 B, the discharge opening  33 , and the like. That is, the guide unit  47 , the recording head  38 , the conveyance belt  37 A, and the sheet support member  37 B are positioned along the conveyance path  43 . 
     The recording head  38  is spaced from the conveyance roller pair  36  to the conveyance orientation  8 A in the front-rear direction  8 . The recording head  38  is positioned above the conveyance path  43  in the up-down direction  7 . The recording head  38  includes a discharge module  38 A. A lower surface of the discharge module  38 A is a nozzle surface  38 B. The nozzle surface  38 B is parallel to the conveyance path  43  and faces a support surface  37 E in the up-down direction  7 . The up-down direction  7  is an example of a crossing (intersecting) direction. The nozzle surface  38 B has a rectangular shape in plan view when seen from below. Nozzles  38 C are arranged in a row in the left-right direction  9  in a specified area  38 D of the nozzle surface  38 B. Only one row of the nozzles  38 C is depicted in  FIG. 2 . The nozzles  38 C may be arranged in two or more rows separated from each other in the front-rear direction  8 . 
     The tank  42  stores ink. The ink is a liquid containing a pigment, a resin curable by ultraviolet rays, and any other additive. The ink has a viscosity suitable for uniformly dispersing the pigment. The pigment imparts a color to the ink. The ink in the tank  42  is supplied to the discharge module  38 A through a tube (not depicted). 
     The discharge module  38 A stores a small amount of ink supplied from the tank  42 . The discharge module  38 A discharges ink droplets in a discharge orientation  7 A (see  FIG. 2 ) from the nozzles  38 C to the label  53  on the separator  52  passing through the conveyance path  43  below the recording head  38 . The discharge orientation  7 A is a downward direction. 
     The conveyance belt  37 A, a driving roller  37 C, and a driven roller  37 D are positioned below the recording head  38  in the up-down direction  7  and are positioned at the front side of the conveyance roller pair  36  in the front-rear direction  8  separately from the conveyance roller pair  36 . The conveyance belt  37 A is an endless belt, and is an example of a support member or an example of a second conveyance member. As depicted in  FIG. 2 , the conveyance belt  37 A is stretched between the driving roller  37 C and the driven roller  37 D separated from each other in the front-rear direction  8 . The driving roller  37 C rotates by driving force from a motor (not depicted), thus rotating the conveyance belt  37 A and the driven roller  37 D. 
     As depicted in  FIG. 2  and  FIG. 3B , the conveyance belt  37 A has the support surface  37 E. The support surface  37 E is a portion included in an upper end of the conveyance belt  37 A and having a rectangular shape. The support surface  37 E has a symmetrical shape with respect to the sheet passing center plane C (see  FIG. 3B ). The nozzle surface  38 B of the recording head  38  faces the support surface  37 E in a normal orientation  7 B of the support surface  37 E (see  FIG. 2 ). The support surface  37 E is narrower than a smallest width of the separator  52  in the left-right direction  9 . The driving roller  37 C and the driven roller  37 D have substantially the same width as the support surface  37 E in the left-right direction  9 . The support surface  37 E applies conveyance force to the separator  52  while supporting the separator  52  being conveyed between the conveyance roller pairs  36  and  40  from below. 
     As depicted in  FIG. 1B , a distance from the front end  52 A of the separator  52  to the leading small hole row  52 B is defined as a distance E. In  FIG. 2 , a rear end of the support surface  37 E is separated from the nip D in the conveyance orientation  8 A by a distance shorter than the distance E. The rear end of the support surface  37 E may be separated from the nip D in the conveyance orientation  8 A by a distance longer than the distance E. 
     As depicted in  FIG. 3B , the sheet support member  37 B has a left support member  371 L and a right support member  371 R. The left support member  371 L is positioned at the left side of the conveyance belt  37 A such that the left support member  371 L is adjacent to the conveyance belt  37 A. The right support member  371 R is positioned at the right side of the conveyance belt  37 A such that the right support member  371 R is adjacent to the conveyance belt  37 A. The left support member  371 L and the right support member  371 R are positioned between a rotation axis of the driving roller  37 C and a rotation axis of the driven roller  37 D in the front-rear direction  8 . 
     Channels  372 L arranged in the left-right direction  9  are defined by a bottom portion, and a rear wall and side walls extending upward from the bottom portion of the left support member  371 L. Each channel  372 L is a space that extends in the front-rear direction  8  and is opened forward and upward. At the bottom portion of the left support member  371 L, exhaust ports  373 L opened upward are formed at rear ends of the channels  372 L. The position in the up-down direction of an upper end of the left support member  371 L is substantially the same as the position in the up-down direction of the support surface  37 E. 
     The right support member  371 R and the left support member  371 L are symmetrical with respect to the sheet passing center plane C. The right support member  371 R is formed having channels  372 R and exhaust ports  373 R that are symmetrical to the channels  372 L and the exhaust ports  373 L with respect to the sheet passing center plane C. A distance in the left-right direction  9  between a left end of the left support member  371 L and a right end of the right support member  371 R is the same as or slightly longer than the maximum width of the separator  52 . 
     The sheet support member  37 B supports the separator  52  supported by the support surface  37 E at the left and right sides of the support surface  37 E. In this configuration, upper ends of the channels  372 L and  372 R are closed with the separator  52 . 
     At least one pump  46  (see  FIG. 3B ) is connected to each of the exhaust ports  373 L and  373 R so that fluid can pass therethrough. The pump  46  sucks air in the channels  372 L and  372 R while the separator  52  is being conveyed under the control of the controller  41  (see  FIG. 3B ). This generates air current in the channels  372 L and  372 R. The air current flows from front ends of the respective channels  372 L and  372 R toward the discharge openings  373 L and  373 R in an orientation opposite to the conveyance orientation  8 A. The air current makes atmospheric pressure in the channels  372 L and  372 R lower than atmospheric pressure above the separator  52 . As a result, the separator  52  supported by the left support member  371 L and the right support member  371 R is attracted to upper ends of the left support member  371 L and the right support member  371 R, and follows the support surface  37 E of the conveyance belt  37 A. Thus, the separator  52  is conveyed in the conveyance orientation  8 A not only by conveyance force from the conveyance roller pairs  36  and  40  but also by conveyance force from the conveyance belt  37 A. The sheet support member  37 B and the pump  46  are an example of a suction (attraction) mechanism. The suction mechanism is not limited to a combination of the sheet support member  37 B and the pump  46 . The suction mechanism may be a combination of a suction belt (i.e., a conveyance belt having suction holes) and a pump that sucks air around the conveyance belt through the suction holes. The suction mechanism may be an electrostatic suction (attraction) type conveyor belt. 
     &lt;Guide Unit  47 &gt; 
     As depicted in  FIG. 2 , the guide unit  47  is positioned between the conveyance roller pair  36  and the recording head  38  in the conveyance orientation  8 A. The guide unit  47  has an upper guide member  471 , a lower guide member  472 , a pair of bearings  473 A, a small-diameter roller  474 , a pair of bearings  473 B, and a large-diameter roller  475 , as depicted in a frame in  FIG. 2  that is indicated by a two-dot chain line and is an enlarged view of the guide unit  47 . The guide unit  47  is an example of a first guide member. A right side surface of the guide unit  47  is depicted in the frame of  FIG. 2 . 
     As depicted in  FIG. 2 , the upper guide member  471  is positioned between the conveyance roller  36 A and the support surface  37 E in the conveyance orientation  8 A. The upper guide member  471  is positioned slightly above the conveyance path  43  in the up-down direction  7 . As depicted in  FIG. 4A , the upper guide member  471  is slightly larger than the sheet support member  37 B in the left-right direction  9 . The upper guide member  471  has a symmetrical shape with respect to the sheet passing center plane C. 
     As depicted in  FIG. 4B , the upper guide member  471  has an upper base  471 A and four upper ribs  471 B. The upper base  471 A is an upper portion of the upper guide member  471 . As depicted in  FIGS. 4A and 4B , the upper base  471 A has a rectangular plate-like shape extending in the front-rear direction  8  and the left-right direction  9 . As depicted in  FIG. 4B , the four upper ribs  471 B having a comb-like shape extend downward from a lower surface of the upper base  471 A. Specifically, the four upper ribs  471 B extend in the front-rear direction  8  and arranged in the left-right direction  9  at regular intervals F. Two of the four upper ribs  471 B positioned inside are symmetrical with respect to the sheet passing center plane C. Each extended end surface of the upper rib  471 B is an example of one of the first guide surface and the second guide surface. 
     As depicted in  FIG. 2 , the lower guide member  472  is positioned between the pinch roller  36 B and the conveyance belt  37 A in the conveyance orientation  8 A. The lower guide member  472  is positioned immediately below the upper guide member  471  in the up-down direction  7  with a slight space through which the separator  52  can pass. As depicted in  FIG. 4B , the lower guide member  472  has a symmetrical shape with respect to the sheet passing center plane C. The lower guide member  472  is slightly larger than the sheet support member  37 B in the left-right direction  9 . 
     As depicted in  FIG. 4B , the lower guide member  472  has a lower base  472 A and five lower ribs  472 B. The lower base  472 A is a lower portion of the lower guide member  472 . As depicted in  FIGS. 2 and 4B , the lower base  472 A has a rectangular plate-like shape extending in the front-rear direction  8  and the left-right direction  9 . The five lower ribs  472 B extend in the front-rear direction  8  and arranged in the left-right direction  9  at regular intervals F. As depicted in  FIG. 4B , the five lower ribs  472 B having a comb-like shape extend upward from an upper surface of the lower base  472 A. Specifically, a center lower rib  472 B in the left-right direction  9  among the five lower ribs  472 B has a symmetrical shape with respect to the sheet passing center plane C. The center lower rib  472 B is positioned between two upper ribs  471 B that are positioned inside in the left-right direction  9  and included in the four upper ribs  471 B. Each extended end surface of the lower rib  472 B is an example of the other of the first guide surface and the second guide surface. 
     In  FIG. 4B , arcs G 1  and G 2  are auxiliary imaginary lines for specifying the shapes of the upper ribs  471 B and the lower ribs  472 B in more detail. The arcs G 1  and G 2  have a symmetrical shape with respect to the sheet passing center plane C in a plane parallel to the up-down direction  7  and the left-right direction  9 . The arcs G 1  and G 2  are convex downward. The curvatures of the arcs G 1  and G 2  are not particularly limited, but are preferably equal to each other and have a value as small as possible. Lower ends G 11  and G 21  of the arcs G 1  and G 2  intersect with the sheet passing center plane C. The arc G 2  is positioned above the arc G 1  and separated from the arc G 1  to an extent that the separator  52  can pass therethrough. Specifically, each of the upper base  471 A and the lower base  472 A has a width equal to or slightly larger than the maximum width of the separator  52  in the left-right direction  9 . The distance between the arcs G 1  and G 2  is much smaller than the width in the left-right direction  9  of each of the upper base  471 A and the lower base  472 A. The distance between the arc G 1  and the arc G 2  corresponds to a distance between the first guide surface and the second guide surface. 
     The extended end face of the center lower rib  472 B in the left-right direction  9  is substantially at the same position as the lower end G 11  of the arc G 1  in the up-down direction  7  when seen from the front-rear direction  8 . The extended end faces of the remaining other lower ribs  472 B are brought in contact with the arc G 1 . The extended end faces of the remaining other lower ribs  472 B may intersect with the arc G 1 . Each of the upper ribs  471 B intersects with or is brought into contact with the arc G 2 . The extended end surfaces of the upper ribs  471 B and the lower ribs  472 B may be parallel to the left-right direction  9  when seen from the front-rear direction  8 . Extended ends of the upper ribs  471 B and the lower ribs  472 B may be inclined to the left-right direction  9  along the arcs G 1  and G 2 . 
     Rear ends of the upper ribs  471 B and the lower ribs  472 B are preferably positioned immediately downstream of the nip D in the conveyance orientation  8 A. This allows the separator  52  conveyed or fed from the conveyance roller pair  36  to be conveyed or fed between the upper ribs  471 B and the lower ribs  472 B. 
     A pair of support plates  476  extends in the conveyance orientation  8 A from left and right ends at the front side of the upper guide member  471 . The support plates  476  extend to a position slightly rear side of the recording head  38  in the conveyance orientation  8 A (see  FIG. 2 ). Each support plate  476  is positioned slightly above the conveyance path  43  in the up-down direction  7 . The support plates  476  have a plate-like shape which is thin in the left-right direction  9  and are separated from each other in the left-right direction  9 . 
     In the pair of support plates  476 , the pair of bearings  473 B is positioned above the rear end of the support surface  37 E. The large-diameter roller  475  is an example of a second rotating body. The large-diameter roller  475  has a larger diameter than the small-diameter roller  474 . The large-diameter roller  475  is supported by the pair of bearings  473 B to be rotatable about an axial core (an example of a third axis) extending in the left-right direction  9 . A lower end of the large-diameter roller  475  comes into contact with the rear end (i.e., an upstream end in the conveyance orientation  8 A) of the support surface  37 E and rotates along with (rotated by) the rotation of the conveyance belt  37 A. Further, the large-diameter roller  475  has substantially the same width as the support surface  37 E in the left-right direction  9 . Further, the large-diameter roller  475  has a symmetrical shape with respect to the sheet passing center plane C. The large-diameter roller  475  is urged (biased) downward by an urging (biasing) member (not depicted, e.g., a spring). The large-diameter roller  475  is thus brought into contact under pressure with the conveyance belt  37 A. 
     The pair of bearings  473 A is positioned in the pair of support plates  476  at the slightly front side of the large-diameter roller  475 . The small-diameter roller  474  is an example of a first rotating body. The small-diameter roller  474  is supported by the pair of bearings  473 A to be rotatable around an axial core (an example of a second axis) extending in the left-right direction  9 . A lower end of the small-diameter roller  474  comes into contact with the support surface  37 E from above. The small-diameter roller  474  is longer than the conveyance belt  37 A in the left-right direction  9  and has substantially the same length as a distance between the left and right ends of the sheet support member  37 B. 
     &lt;Operation of Guide Unit  47 &gt; 
     In the image recording apparatus  100  of the above configuration, the separator  52  conveyed or fed from the conveyance roller pair  36  is conveyed or fed between the rear ends of the upper ribs  471 B and the rear ends of the lower ribs  472 B. The separator  52  passes between the extended ends of the upper ribs  471 B and the extended ends of the lower ribs  472 B. In this situation, the extended end surfaces of the upper ribs  471 B and the extended end surfaces of the lower ribs  472 B deform the separator  52  so that the separator has downwardly convex shape in which a portion closer to the center in the left-right direction  9  of the separator  52  is positioned lower than any other portion than the center. Specifically, the separator  52  is deformed to have a symmetrical shape in the left-right direction  9  with respect to the sheet passing center plane C. 
     The separator  52  that passed through the upper ribs  471 B and the lower ribs  472 B is conveyed or fed between the large-diameter roller  475  and the support surface  37 E. In this situation, the large-diameter roller  475  is rotated by force from the conveyance belt  37 A that rotates and conveys the separator  52  in the conveyance orientation  8 A. The separator  52  is nipped between the large-diameter roller  475  and the conveyance belt  37 A and is conveyed thereby in the conveyance orientation  8 A while the first surface  52 C of the separator  52  is along with the support surface  37 E. Since the large-diameter roller  475  is urged downward, conveyance force is applied to the center in the width direction of the separator  52 . Thus, the separator  52  is not likely to skew with respect to the conveyance orientation  8 A. 
     The small-diameter roller  474  is positioned downstream of the large-diameter roller  475  in the conveyance orientation  8 A. The small-diameter roller  474  rotates along with the conveyance belt  37 A while being brought into contact with the conveyance belt  37 A. The separator  52  is conveyed or fed between the small-diameter roller  474  and the conveyance belt  37 A. The small-diameter roller  474  comes into contact with an entire area in the left-right direction  9  of the separator  52  from above. This allows the small-diameter roller  474  to guide the entire area of the first surface  52 C of the separator  52  not only to the support surface  37 E but also to the upper ends of the left support member  371 L and the right support member  371 R so that the entire area of the first surface  52 C of the separator  52  is along not only the support surface  37 E but also the upper ends of the left support member  371 L and the right support member  371 R. Since airflow is generated in the channels of the left support member  371 L and the right support member  371 R by the pump  46 , the first surface  52 C of the separator  52  comes into contact with and is attracted to the upper ends of the left support member  371 L and the right support member  371 R. This makes the nozzle surface  38 B of the recording head  38  and the labels  53  on the separator  52  parallel to each other. 
     &lt;Working Effect of Guide Unit  47 &gt; 
     In the image recording apparatus  100 , in some situations, the front end  52 A of the separator  52  is conveyed to a position immediately below the nozzle surface  38 B of the recording head  38  only by the conveyance force of the conveyance roller pair  36 . In those situations, when a simple guide member having no upper ribs  471 B and no lower ribs  472 B is positioned between the conveyance roller pair  36  and the conveyance belt  37 A, the front end  52 A of the separator  52  may be caught by the guide member or the support surface  37 E, which may cause the separator  52  to buckle at the small holes  52 B. 
     However, the upper guide member  471  and the lower guide member  472  of the guide unit  47  guide the separator  52  so that the separator  52  has a curved shape in a cross-sectional view orthogonal to the conveyance orientation  8 A. Specifically, the upper guide member  471  and the lower guide member  472  convey the separator  52  so that the separator  52  becomes convex from the upper guide member  471  toward the lower guide member  472  in a cross-sectional view. That is, the upper guide member  471  and the lower guide member  472  convey the separator  52  without causing a state where any other portion than the center of the front end  52 A bulges or swells in the normal orientation  7 A with respect to the center of the front end  52 A. In other words, the convex shape extending from each extended end surface of the upper rib  471 B toward each extended end surface of the lower rib  472 B is formed, and the left and right ends of the separator  52  are lifted above slightly inner portions thereof. The front end  52 A is thus not likely to be caught by the lower guide member  472  and the support surface  37 E, and the separator  52  is not likely to buckle at the small holes  52 B. By curving the separator  52  in the left-right direction  9 , even when a force is rearwardly applied to the front end  52 A of the separator  52 , a bend or buckling of the separator  52  in the up-down direction  7  will be suppressed. 
     When the rear end of the support surface  37 E is separated from the nip D by a distance shorter than the distance E, the small hole row  52 B is positioned upstream of the nip D in the conveyance orientation  8 A while the separator  52  is conveyed between the upper guide member  471  and the lower guide member  472 . Thus, the buckling of the separator  52  is suppressed more appropriately. 
     Further, the upper guide member  471  and the lower guide member  472  curve the separator  52  so that the separator  52  forms a convex shape that has a symmetrical shape in the left-right direction  9  with respect to the sheet passing center plane C. The separator  52  is thus not likely to skew between the upper guide member  471  and the lower guide member  472  with respect to the conveyance orientation  8 A. 
     The large-diameter roller  475  rotates while being brought in contact with the rear end of the support surface  37 E. This applies conveyance force in the conveyance orientation  8 A to the separator  52 . Further, rotating the small-diameter roller  474  on the support surface  37 E causes the entire area in the left-right direction  9  of the separator  52  to come into contact with and be attracted to the support surface  37 E as well as the respective upper ends of the left support member  371 L and the right support member  371 R. 
     The distance between the arcs G 1  and G 2  is much smaller than the widths in the left-right direction  9  of the upper base  471 A and the lower base  472 A. It is thus possible for the upper guide member  471  and the lower guide member  472  to gently curve the separator  52  in one convex shape, inhibiting the stress applied to the separator  52 . 
     &lt;Modifications&gt; 
     In the embodiment, the upper guide member  471  and the lower guide member  472  curve the separator  52  into an arc shape. However, the present disclosure is not limited to this. As depicted in  FIG. 5A , the upper ribs  471 B of the upper guide member  471  and the lower ribs  472 B of the lower guide member  472  may be arranged so that the separator  52  curves in a wavy shape. In particular, the upper ribs  471 B and the lower ribs  472 B curve the separator  52  so that the left and right ends of the separator  52  having the wavy shape become convex downward. In other words, the convex shape extending from each extended end surface of the upper rib  471 B toward each extended end surface of the lower rib  472 B is formed, and the left and right ends of the separator  52  are lifted above slightly inner portions thereof. The left and right ends of the front end  52 A of the separator  52  are thus not likely to be caught by the lower guide member  472  and the support surface  37 E, and the separator  52  is not likely to buckle at the small holes  52 B. 
     More specifically, the upper ribs  471 B extend downward from the left and right positions different from each other in the upper base  471 A by the same amount. Further, the lower ribs  472 B extend upward from the left and right positions different from each other in the lower base  472 A by the same amount. Each of the lower ribs  472 B is positioned at the center of two upper ribs  471 B adjacent to each other in the left-right direction  9 . The extended end of each lower rib  472 B is positioned above the extended end of each upper rib  471 B in the up-down direction  7 . 
     In this embodiment, the upper ribs  471 B of the upper guide member  471  and the lower ribs  472 B of the lower guide member  472  curve the separator  52 . The upper guide member  471  and the lower guide member  472 , however, may curve the separator  52  in a downward convex shape or wavy shape by use of small rollers  477  arranged in the left-right direction  9 , instead of at least one of the upper ribs  471 B and the lower ribs  472 B, as depicted in  FIG. 5B . The upper guide member  471  and the lower guide member  472  depicted in  FIG. 5B  also cause the separator  52  to have a convex shape from the extended end surface of each upper rib  471 B toward the extended end surface of each lower rib  472 B, and cause the left and right ends of the separator  52  to be lifted above slightly inner portions thereof. Also in this configuration, the separator  52  is not likely to buckle at the small holes  52 B.  FIG. 5B  depicts an example in which the rollers  477  are arranged on the upper guide member  471 . 
     In this embodiment, the four upper ribs  471 B are arranged in the left-right direction  9  at the regular intervals F, and the five lower ribs  472 B are arranged in the left-right direction  9  at the regular intervals F (see  FIG. 4B ). The present disclosure, however, is not limited thereto. The four upper ribs  471 B may be arranged in the left-right direction  9  at non-uniform intervals provided that the respective extended end surfaces intersect with or are brought into contact with the arc G 2 . The five lower ribs  472 B may be arranged in the left-right direction  9  at non-uniform intervals provided that the respective extended end surfaces intersect with or are brought into contact with the arc G 1 . 
     In this embodiment, the upper guide member  471  includes the upper ribs  471 B, and the lower guide member  472  includes the lower ribs  472 B. The present disclosure, however, is not limited thereto. The lower surface of the upper base  471 A of the upper guide member  471  may have a shape along the arc G 2  in plan view from the front-rear direction  8 . The upper surface of the lower base  472 A of the lower guide member  472  may have a shape along the arc G 1  in plan view from the front-rear direction  8 . 
     In the embodiment, the entire area in the left-right direction  9  of the separators  52  is along the support surface  37 E of the conveyance belt  37 A, the upper end of the left support member  371 L, and the upper end of the right support member  371 R by rotating the small-diameter roller  474  that is long in the left-right direction  9  on the conveyance belt  37 A. However, as depicted in  FIG. 6 , the guide unit  47  may include small-diameter rollers  474 A arranged along the left-right direction  9  at the same position in the up-down direction and the front-rear direction as the small-diameter roller  474 , instead of the small-diameter roller  474 . 
     As depicted in  FIGS. 7A and 7B , the guide unit  47  may include a guide member  478 , instead of the small-diameter roller  474  (see  FIG. 4A ). As depicted in  FIGS. 7B and 7C , the guide member  478  has a guide surface  478 A. The guide member  478  is an example of a fifth guide member and the guide surface  478 A is an example of a fifth guide surface. The guide surface  478 A is a lower surface of the guide member  478 . The guide surface  478 A is positioned at the slightly front side of the large-diameter roller  475  and positioned at the slightly upper side of the support surface  37 E with a gap. The guide surface  478 A has a shape in which a downstream end is closer to the support surface  37 E than an upstream end in plan view from the left-right direction  9 . 
     In the embodiment, the image recording apparatus  100  records an image on each label  53  on the separator  52  by the recording head  38  in accordance with the ink-jet system. The present disclosure, however, is not limited thereto. The image recording apparatus  100  may record an image on each label  53  by an image forming section in accordance with an electrophotographic system or a recording head in accordance with a thermal transfer system. 
     In the embodiment, the separator  52  is conveyed by the conveyance roller pair  36 . The present disclosure, however, is not limited thereto. In the image recording apparatus  100 , the separator  52  may be conveyed by any other conveyance member such as a conveyance belt, instead of the conveyance roller pair  36 . 
     In the embodiment, the separator  52  is conveyed in the conveyance orientation  8 A by the conveyance belt  37 A and the sheet support member  37 B while being supported thereby at the position below the recording head  38 . The present disclosure, however, is not limited thereto. In the image recording apparatus  100 , the separator  52  may be conveyed in the conveyance orientation  8 A while being supported by a suction belt, instead of the conveyance belt  37 A and the sheet support member  37 B, at a position below the recording head  38 . 
     The tank  42  is not limited to a tank storing one color of ink. The tank  42  may include tanks that store inks of multiple colors. 
     It is not indispensable to form the discharge opening  33  in the front surface  32 F of the lower casing  32 . For example, the discharge opening  33  may be formed in the upper surface  31 U of the upper casing  31 , and the label  53  for which image recording has been performed may be discharged obliquely upward or upward through the discharge opening  33 . 
     Although the image recording apparatus  100  is used with the front surface  32 F and the rear surface  32 B of the lower casing  32  along the up-down direction  7  and the left-right direction  9 , the usable posture of the image recording apparatus  100  is not limited thereto. 
     According to the above configuration, it is possible to inhibit buckling of the sheet.