Patent Publication Number: US-2023144080-A1

Title: Image recording apparatus

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from Japanese Patent Application No. 2021-183927 filed on Nov. 11, 2021. The entire content of the priority application is incorporated herein by reference. 
     BACKGROUND ART 
     There is a known image recording apparatus which heats at least one of a sheet and a liquid discharged onto the sheet so as to fix the liquid to the sheet. An example of such a printing apparatus is provided with a recording head which records a color measuring pattern on a sheet; a drying part which dries the sheet on which the color measuring pattern is recorded; and a color measuring device which measures the color measuring pattern. In an example of such a printing apparatus, a near infrared lamp in the drying part is covered by a drying part-cover from thereabove, thereby preventing any radiation and/or diffusion of the drying heat to the outside of the drying part; and the color measuring device is covered by a color measuring device-cover from thereabove, thereby preventing any variation or fluctuation in the color measuring due to any increase in the temperature inside the color measuring device-cover. 
     DESCRIPTION 
     Although the above-described printing apparatus is provided with the drying part-cover and the color measuring device-cover, the printing apparatus is not considered to be sufficiently suppressing any adverse effect caused by the radiation and/or the diffused heat from the near infrared lamp to another or other electric part(s) or component(s). 
     An object of the present disclosure is to provide an image recording apparatus configured to heat a sheet and/or a liquid discharged onto the sheet so as to fix the liquid to the sheet, the image recording apparatus being capable of suppressing the effect or influence of the heat with respect to a reading part. 
     (1) An image recording apparatus according to an aspect of the present disclosure includes: a conveyer configured to convey a sheet in a conveying direction; a head configured to discharge a liquid toward the sheet; a heater configured to heat the sheet and/or the liquid on the sheet; a reader positioned downstream in the conveying direction of the heater, the reader being configured to read an image, on the sheet, formed by the head and the heater; and a holder positioned between the reader and the heater in the conveying direction, the holder being configured to hold a body of rotation configured to contact a recording surface of the sheet. In a crossing direction orthogonal to the conveying direction and crossing the recording surface of the sheet being conveyed by the conveyer, both ends in the crossing direction of the holder are positioned outside of both ends in the crossing direction of the reader. 
     According to the aspect of the present disclosure, since the holder functions as a heat shielding wall (heat insulating wall) with respect to the radiation heat of the heater (fixer, fixing part), the radiation heat of the heater is less likely to reach the reader (reading part). 
     (2) In an aspect of the present disclosure, the holder may have a first wall positioned upstream in the conveying direction of a rotation axis of the body of rotation and extending in the crossing direction, and a second wall positioned downstream in the conveying direction of the rotation axis of the body of rotation and extending in the crossing direction. 
     Since each of the two walls which are the first wall and the second wall functions as a heat shielding wall with respect to the radiation heat of the heater, the radiation heat of the heater is less likely to reach the reader. 
     (3) In an aspect of the present disclosure, the first wall and the second wall may extend in a first direction crossing the conveying direction and crossing the crossing direction. 
     In each of the first wall and the second wall, the function as the heat shielding wall with respect to the radiation heat of the heater is further exhibited. 
     (4) In an aspect of the present disclosure, the holder may further include a third wall closing a space between a first end in the crossing direction of the first wall and a first end in the crossing direction of the second wall, and a fourth wall closing a space between a second end in the crossing direction of the first wall and a second end in the crossing direction of the second wall. 
     Since an air layer (air cavity) surrounded by the first wall, the second wall, the third wall and the fourth wall is formed or defined in the holder, the radiation heat of the heater is less likely to be transmitted to the holder. 
     (5) In an aspect of the present disclosure, a slit may be formed in the third wall. A part of the body of rotation may protrude to outside of the third wall via the slit. 
     It is possible to cause the body of rotation to make contact with the recording surface of the sheet, while maintaining or retaining the air layer surrounded by the first wall, the second wall, the third wall and the fourth wall. 
     (6) In an aspect of the present disclosure, a cleaner configured to make contact with the body of rotation may be positioned between the first wall and the second wall. The cleaner may be aligned with the body of rotation in the crossing direction. 
     It is possible to remove the liquid adhered to the body of rotation by the cleaner. 
     (7) In an aspect of the present disclosure, the image recording apparatus may further include a frame configured to support the holder. The holder may be detachably attached with respect to the frame. 
     Since a user is capable of detaching the holder from the frame, the user is capable of easily exchanging the cleaner. 
     (8) In an aspect of the present disclosure, both ends in the first direction of the first wall may be positioned outside, respectively, of both ends in the first direction of the heater. 
     In the first wall, the function as the heat shielding wall with respect to the radiation heat of the heater is further exhibited. 
     According to the present disclosure, it is possible to suppress occurrence of any reading failure (unsatisfactory reading) in the image recording apparatus which heats the sheet and/or the liquid discharged onto the sheet so as to fix the liquid to the sheet. 
    
    
     
         FIG.  1    is a perspective view depicting the outer appearance of an image recording apparatus  10 . 
         FIG.  2    is a perspective view depicting the outer appearance of the image recording apparatus  10  in a state that an upper casing  31  is opened. 
         FIG.  3    is a perspective view depicting side frames  20  and  21  attached to a base  23 . 
         FIG.  4    is a cross-sectional view of a IV-IV cross section of  FIG.  1   . 
         FIG.  5    is a perspective view of the upper casing  31  as seen obliquely therebelow. 
         FIG.  6    is a perspective view of a state that a holding member  73  is attached to a first shaft  84  and a second shaft  85  of  FIG.  5   . 
         FIG.  7    is a perspective view of the holding member  73 . 
         FIG.  8    is a cross-sectional view of a VIII-VIII cross section of  FIG.  7   . 
         FIG.  9    is a cross-sectional view of a IX-IX cross section of  FIG.  7   . 
         FIG.  10    is a plan view depicting the holding member  73 . 
     
    
    
     In the following, an embodiment of the present disclosure will be explained, with reference to the drawings as appropriate. Note that the embodiment which is to be explained below is merely an example in which the present disclosure is embodied; it is needless to say that the embodiment can be appropriately changed without changing the gist of the present disclosure. In the following explanation, a direction (orientation) in which a discharge port  33  faces or is oriented in an image recording apparatus  10  is referred to as a front direction (front orientation), a direction (orientation) opposite to the front direction is referred to as a rear direction (rear orientation). The front direction and the rear direction are collectively referred to as a front-rear direction. An up-down direction orthogonal to the front-rear direction is referred to as an up-down direction. A direction orthogonal to the front-rear direction and the up-down direction is referred to as a left-right direction. The up direction (up orientation) of the up-down direction is referred to as an up direction (up orientation), the down direction (down orientation) in the up-down direction is referred to as a down direction (down orientation). In a case that an image recording apparatus  10  is seen in the rear direction, the left direction (orientation) of the left-right direction is referred to as a left direction (left orientation), and the right direction (right orientation) in the left-right direction is referred to as a right direction (right orientation). 
     Configuration of Outer Appearance of Image Recording Apparatus  10   
     The image recording apparatus  10  as depicted in  FIG.  1    records, in the ink-jet recording system, an image on a sheet S pulled or drawn from a roll body  37  (see  FIG.  4   ). Note that in  FIGS.  1  to  4   , the image recording apparatus  10  and respective parts or components thereof are schematically depicted. 
     As depicted in  FIG.  1   , the image recording apparatus  10  is provided with a casing  30 . The casing  30  is provided with an upper casing  31  and a lower casing  32 . The upper casing  31  and the lower casing  32  have, as a whole, a shape which is substantially rectangular parallelepiped, and have a size which can be placed on a table, desk, etc. In the following, in a case that an explanation is made regarding the casing  30 , the explanation is made assuming that the upper casing  31  and the lower casing  32  have the rectangular parallelepiped shape as a whole. 
     The casing  30  has a right surface  30 R, a left surface  30 L, an upper surface  30 U, a lower surface  30 D, a front surface  30 F, and a rear surface  30 B. The right surface  30 R and the left surface  30 L are positioned apart in the left-right direction. The upper surface  30 U and the lower surface  30 D are positioned apart in the up-down direction. The front surface  30 F and the rear surface  30 B are positioned apart in the front-rear direction. 
     The upper casing  31  is connected to the rear surface  30 B of the lower casing  32  so that the upper casing  31  is pivotable (rotatable) around a pivot axis extending in the left-right direction. The upper casing  31  is pivotally moved from a close position depicted in  FIG.  1    so that the front surface  30 F is lifted upward to pivot (rotate) to an open position depicted in  FIG.  2   . In a case that the upper case  31  is pivoted to be in the open position, an internal space  30 A ( FIG.  4   ) of the casing  30  is exposed to the outside. Note that in  FIG.  2   , an internal structure of the casing  30  is omitted. 
     As depicted in  FIG.  1   , the front surface  30 F of the casing  30  is formed with a discharge port  33  which extended to be slender in the left-right direction. The center in the left-right direction of the discharge port  33  is positioned on the right side with respect to the center in the left-right direction of the front surface  30 . The discharge port  33  causes the internal space  30 A of the casing  30  to communicate with the outside. The sheet S for which image recording has been performed in the internal space  30 A of the casing  30  is discharged to the outside of the casing  30  through the discharge port  33 . 
     An operation panel  44  is provided on the front surface  30 F of the casing  30 . The operator panel  44  is positioned above the discharge port  33 . The operation panel  44  receives input, from a user, the input being for operating the image recording apparatus  10  or for confirming a variety of kinds of settings. 
     As depicted in  FIG.  3   , two side frames  20 ,  21  are provided on the internal space  30 A of the casing  30 . Each of the side frames  20 ,  21  has a shape of a flat plate made of a steel plate, and a cutout, a through hole, etc., of which shape(s) is/are in accordance with a member which is supported by each of the side frames  20 ,  21 , are formed in each of the side frames  20  and  21 , as appropriate. The two side frames  20 ,  21  are positioned to be apart from each other in the left-right direction. The side frames  20 ,  21  are connected to a base  23  forming the lower surface  30 D of the casing  30 . The connection between the side frames  20 ,  21  and the base  23  is made by a screwing, a welding, etc. 
     Internal Configuration of Image Recording Apparatus  10   
     A roll-body holder  35 , a tensioner  45 , a conveying part (conveyer)  71 , a recording head  38 , a supporting mechanism  116 , a fixing part  39 , a jam cover  81 , a supporting member  46 , a contact image sensor (hereinafter referred to as “CIS”)  25  (an example of a “reader”), a cutter unit  26  are arranged at a location between the side frames  20 ,  21  in the internal space  30 A. 
     As depicted in  FIG.  4   , in the internal space  30 A, a partition wall  41  is provided between the side frames  20  and  21 . The partition wall  41  is located at a lower part on the rear side in the internal space  30 A. The partition wall  41  cooperates with the lower casing  32  to define a sheet accommodating space  30 C. The sheet accommodating space  30 C is a space surrounded by the partition wall  41  and the lower casing  32  and separated or isolated from the recording head  38 , etc. 
     The roll body  37  is accommodated in the sheet accommodating space  30 C. The roll body  37  has a core tube and a long sheet S. The sheet S is wound around the core tube in a roll shape in a circumferential direction of the axis of the core tube. The sheet S may have a width ranging from a minimum width to a maximum width in which the image recording apparatus  10  is capable of recording an image. Namely, a plurality of types of the roll body  37  having different widths are accommodatable in the sheet accommodating space  30 C. Note that it is allowable that the roll body  37  does not have the core tube and that the sheet S is wound in a roll shape so that the sheet S is installable in the roll-body holder  35 . Also note that the sheet accommodating space  30 C may accommodate a fan-folded paper. 
     The roll-body holder  35  is positioned in the sheet accommodating space  30 C. The roll body  37  is installed in the roll-body holder  35 . In a case that the roll body  37  is installed in the roll-body holder  35 , the roll-body holder  35  supports the roll body  37  so that the roll body  37  is rotatable in the circumferential direction of the axis of the core tube of the roll body  37  in a state that the axis of the core tube is along the left-right direction. 
     The roll-body holder  35  is provided with a pair of side guides  115  separated from each other in the left-right direction. A distance between the pair of side guides  115  in the left-right direction is changeable. A user moves the pair of side guides  115  so as to cause the pair of side guides  115  to make contact, respectively, with left and right ends of the roll body  37 , in accordance with the width (the size along the left-right direction) of the roll body  37  installed to the roll-body holder  35 . The roll body  37  of which left and right ends make contact, respectively, with the pair of side guides  115  is positioned so that the center in the width direction of the sheet S is coincident with the center in the left-right direction of a conveying route  43 . The roll-body holder  35  rotates in a case that the roll-body holder  35  receives a driving force from a non-illustrated motor. Accompanying with the rotation of the roll-body holder  35 , the roll body  37  supported by the roll-body holder  35  also rotates. 
     A rear part of the sheet accommodating space  30 C is opened upward. Specifically, a gap  42  is defined between the partition wall  41  and the rear surface  30 B, namely, at a position above a rear end of the roll body  37 . The sheet S is drawn upward from the rear end of the roll body  37 , and the drawn sheet S is guided to the tensioner  45  via the gap  42 . 
     At a rear part of the internal space  30 A, the tensioner  45  is positioned above the partition wall  41 . The tensioner  45  is a roller supported by the side frames  20 ,  21  so that the tensioner  45  is rotatable. The tensioner  45  is supported by the side frames  20 ,  21  so that the tensioner  45  is movable in the front-rear direction. An urging force in the rear direction is applied to the tensioner  45  by an urging member such as a spring, etc. 
     The conveying part  71  draws the sheet S from the roll body  37 , and conveys the sheet S in the front direction (an example of a “conveying direction”). The conveying part  71  has a conveying roller pair  36 , a first discharging roller pair  40 , and a second discharging roller pair  72 . 
     The conveying roller pair  36  is positioned in front of the tensioner  45 . The conveying roller pair  36  has a conveying roller  36 A and a pinch roller  36 B. The conveying roller  36 A is rotatably supported by the frames  20  and  21 . The conveying roller  36 A rotates by receiving a driving force from a non-illustrated motor, thereby conveying the sheet S in the front direction while nipping the sheet S between the conveying roller  36 A and the pinch roller  36 B. 
     The first discharging roller pair  40  is positioned in front of the conveying roller pair  36 . The first discharging roller pair  40  has a discharging roller  40 A which makes contact with a lower surface of the sheet S, and spurs  40 B (an example of a “body of rotation”) which makes contact with an upper surface of the sheet S. The discharging roller  40 A is rotatably supported by the side frames  20 ,  21 . The spurs  40 B are rotatably supported by a first spur holder  74  (an example of a “holder”; to be described later on). The discharging roller  40 A rotates by receiving a driving force from a non-illustrated motor, thereby conveying the sheet S in the front direction while nipping the sheet S between the discharging roller  40 A and the spurs  40 B. 
     The second discharging roller pair  72  is positioned in front of the first discharging roller pair  40 . The second discharging roller pair  72  has a discharging roller  72 A which makes contact with the lower surface of the sheet S, and spurs  72 B which makes contact with the upper surface of the sheet S. The discharging roller  72 A is rotatably supported by the side frames  20 ,  21 . The spurs  72 B are rotatably supported by a second spur holder  75  (to be described later on). The discharging roller  72 A rotates by receiving a driving force from a non-illustrated motor, thereby conveying the sheet S in the front direction while nipping the sheet S between the discharging roller  72 A and the spurs  72 B. 
     The recording head  38  is positioned at a location which is in front of (on the front side with respect to) the conveying roller pair  36  and behind (on the rear side with respect to) the first discharging roller pair  40 . The recoding head  38  has a plurality of nozzles  38 A. Each of the plurality of nozzles  38 A discharges or ejects an ink (an example of a “liquid”) downwardly, as a liquid droplet, toward the sheet S supported by a conveying belt  117 . With this, an image is recorded on the upper surface of the sheet S. A non-illustrated tank which stores the ink is connected to the recording head  38  by a non-illustrated tube so that the ink can be supplied from the tank to the recording head  38 . 
     As the ink, a water-based ink which includes water, a pigment and thermoplastic resin fine particles is used. Note that the ink is not particularly limited, provided that the ink can be fixed to the sheet S by heating. In the present embodiment, the ink adhered to the sheet S is heated by the heating part  39  to thereby melt the thermoplastic resin fine particles; and then the ink is subjected to cooling thereafter to thereby cure or harden the molten resin, thereby fixing the pigment included in the ink to the sheet S. 
     The supporting mechanism  116  is positioned at a location in front of the conveying roller pair  36 . The supporting mechanism  116  is positioned below the recording head  38 . The supporting mechanism  116  face or is opposite to the recording head  38  in the up-down direction. The supporting mechanism  116  has the conveying belt  117 , and a supporting part  118  which supports the conveying belt  117 . A driving force from a non-illustrate motor is transmitted to the conveying belt  117  so as to drive and rotate the conveying belt  117 , thereby causing the conveying belt  117  to convey the sheet S in the front direction while supporting the lower surface of the sheet S. 
     The fixing part (heater)  39  is positioned, in the front-rear direction, between the recording head  38  and the first discharging roller pair  40 . The fixing part  39  is fixed to the side frames  20 ,  21 . The fixing part  39  has: a metallic plate  39   a  which has a shape of a flat plate and which extends in the front-rear direction and the left-right direction; and a polyimide heater  39   b  which is fixed to a lower surface of the metallic plate  39   a.  The metallic plate  39   a  supports the lower surface of the sheet S which is (being) conveyed in the front direction by the conveying belt  117 . Accordingly, a size in the left-right direction of the metallic plate  39   a  is greater than the maximum width, of the sheet S, in which the image recording apparatus  10  is capable of recording an image. The polyimide heater  39   b  heats the lower surface of the metallic plate  39   a . With this, while the sheet S is passing on the metallic plate  39   a,  the thermoplastic resin fine particles included in the ink is melt by the heat of the metallic plate  39   a,  and the molten resin is cured by a cooling by the atmosphere after the sheet S has passed the metallic plate  39   a,  thereby fixing the pigment to the upper surface of the sheet S. Note that it is allowable to heat the metallic plate  39   a  by a heater, such as an infrared heater, instead of the polyimide heater  39   b.    
     The jam cover  81  is arranged so as to cover a location above the fixing part  39 . The jam cover  81  is attached to the side frames  20 ,  21 . The jam cover  81  is formed to have a box shape having an internal space which extends in the front-rear direction, the up-down direction and the left-right direction. An upper surface and a lower surface of the jam cover  81  are rectangular which is longer in the left-right direction than in the front-rear direction. The jam cover  81  is formed of a material made of a resin. The material of the jam cover  81  is not particularly limited, provided that the material is capable of securing a strength and a heat-resisting property which are of not less than a certain level. For example, the jam cover  81  is formed of polypropylene, polycarbonate, a phenol resin, etc. The jam cover  81  has, in the internal space thereof, a plurality of spurs  81 A which project in the down direction from the lower surface of the jam cover  81 . The plurality of spurs  81 A make contact with the upper surface (recording surface) of the sheet S which is (being) conveyed in the front direction by the conveying belt  117 . 
     The supporting member  46  is positioned in front of the fixing part  39 . A front part of the supporting member  46  faces or is opposite to the spurs  72 B in the up-down direction. A rear part of the supporting member  46  faces or is opposite to the spurs  40 B in the up-down direction. The supporting member  46  supports the lower surface of the sheet S which is (being) conveyed in the front direction by the first discharging roller pair  40 . 
     The CIS  25  is positioned in front of the fixing part  39 . The CIS  25  is positioned above the supporting member  46 . The CIS  25  is positioned, in the front-rear direction, between the first discharging roller pair  40  and the second discharging roller pair  72 . The CIS  25  is configured as below. That is, a reflected light, of a light emitted or radiated from a light source such as an LED and reflected off (by) the sheet S, is collected by a gradient index lens and to a line sensor; and the CIS  25  outputs an electric signal corresponding to the intensity of the reflected light received by the line sensor. The CIS  25  is configured to output an electric signal corresponding to a reflected light by an image on the recording surface (upper surface) of the sheet S. A direction in which the line sensor is aligned, namely a reading line, is along the left-right direction. A length of the reading line of the CIS  25  is longer than the maximum width, of the sheet S, in which the image recording apparatus  10  is capable of recording an image. In the present embodiment, a size in the left-right direction of the CIS  25  is similar to a size in the left-right direction of the metallic plate  39   a.    
     The cutter unit  26  is positioned in front of the second discharging roller pair  72 . The cutter unit  26  has a configuration wherein a cutter  28  is mounted on a cutter carriage  27 . The cutter carriage  27  moves in the left-right direction, by a non-illustrated belt-driving mechanism, etc. Accompanying with the movement of the cutter carriage  27 , the cutter  28  moves also in the left-right direction. By the movement of the cutter  28 , the sheet S positioned between the second discharging roller pair  72  and the discharge port  33  is cut along the left-right direction. 
     As depicted in  FIG.  3   , a substrate  130  is fixed to the side frame  20  at a left side part thereof. An arithmetic element serving as a controller, a chip for a communication interface, various connectors, etc., are mounted on the substrate  130 . The substrate  130  is connected, by a non-illustrated flat cable, etc., to the recording head  38 , the motor(s), the operation panel  44 , etc., so that an electrical signal can be transmitted and received. Further, an electric power is supplied from a non-illustrated power supply unit to the substrate  130 . 
     As depicted in  FIG.  5   , a supporting frame  83  (an example of a “frame”) is arranged in the internal space  30 A of the upper casing  31 . Both ends in the left-right direction of the supporting frame  83  are bent downward to thereby form four supporting parts  82 . The four supporting parts  82  each extend in the front-rear direction and in the up-down direction. The four supporting parts  82  are arranged such that two pieces and other two pieces are apart from each other in the left-right direction to form a pair. Each of the four supporting parts  82  has a shape of a substantially rectangular flat plate in which a size thereof in the front-rear direction is longer than a size thereof in the up-down direction. The supporting frame  83  is fixed to an inner wall surface of the upper casing  31 . The two supporting parts  82  which form a pair supports a first shaft  84  having a columnar shape and extending in the left-right direction, and the other two supporting parts  82  which form another pair supports a second shaft  85  having a columnar shape and extending in the left-right direction. The first shaft  84  is positioned on the rear side with respect to the second shaft  85 . 
     As depicted in  FIGS.  5  and  6   , a holding member  73  is detachably attached to the first shaft  84  and the second shaft  85 . As depicted in  FIG.  4   , the holding member  73  is positioned above the supporting member  46 . The holding member  73  is formed of a material made of a resin. The material of the holding member  73  is not particularly limited, provided that the material is capable of securing a strength and a heat-resisting property which are of not less than a certain level. For example, the holding member  73  is formed of polypropylene, polycarbonate, a phenol resin, etc. 
     As depicted in  FIG.  7   , the holding member  73  has a first spur holder  74  (an example of a “holder”), a second spur holder  75 , a first connecting member  76  and a second connecting member  77  which connect the first spur holder  74  and the second spur holder  75 , and a first fitting part  91  and a second fitting part  92  which are detachably fitted, respectively, to the first shaft  84  and the second shaft  85 . 
     As depicted in  FIGS.  4  and  7   , the first spur holder  74  is positioned, in the front-rear direction, between the CIS  25  and the fixing part  39 . The first spur holder  74  holds the spurs  40 B. The first spur holder  74  has a body part  74   a  which is opened in the up direction, a lid part  74   b  (an example of a “fourth wall”) which closes an opening of the body part  74   a,  a plurality of spurs  40 B, and a plurality of spur cleaners  105  (an example of a “cleaner”;  FIGS.  8  and  9   ). The body part  74   a  has a rear wall part  93  (an example of a “first wall”), a front wall part  94  (an example of a “second wall”), a bottom wall part  95  (an example of a “third wall”), a left wall part  96  and a right wall part  97 . 
     As depicted in  FIG.  7   , the rear wall part  93  is positioned behind the spurs  40 B. The rear wall part  93  has a shape of a flat plate which has a thickness in the front-rear direction. The rear wall part  93  extends in the up-down direction and the left-right direction. A front surface and a rear surface of the rear wall part  93  each have a rectangular shape which is longer in the left-right direction than in the up-down direction. As depicted in  FIG.  8   , a length L 5  in the left-right direction (an example of a “first direction”) of the rear wall part  93  is longer than a length in the left-right direction of the metallic plate  39   a  of the fixing part  39 . A left end  93   a  of the rear wall part  93  is located on the left side with respect to a left end  39   aa  of the metallic plate  39   a.  A right end  93   b  of the rear wall part  93  is located on the right side with respect to a right end  39   ab  of the metallic plate  39   a.    
     The front wall part  94  is located in front of the spurs  40 B. The front wall part  94  has a shape of a flat plate which has a thickness in the front-rear direction. The front wall part  94  extends in the up-down direction and the left-right direction. A front surface and a rear surface of the front wall part  94  each have a rectangular shape which is longer in the left-right direction than in the up-down direction. A length in the left-right direction of the front wall part  94  is shorter than a length in the left-right direction of the rear wall part  93 . The front wall part  94  faces the rear wall part  93  in the front-rear direction. 
     The bottom wall part  95  connects or links a lower end  93   c  of the rear wall part  93  and a lower end of the front wall part  94 . The bottom wall part  95  extends in the front-rear direction and the left-right direction. A rear end side of the bottom wall  95  extends in the rear direction and the up direction while being curved, and connects to the lower end  93   c  of the rear wall part  93 . 
     The left wall part  96  has a shape of a flat plate which has a thickness in the left-right direction. The left wall part  96  extends in the front-rear direction and the up-down direction. The left wall part  96  connects a location in the vicinity of a left end part in the rear surface of the front wall part  94  and a location in the vicinity of a left end part in the front surface of the rear wall part  93 . The right wall part  97  has a shape of a flat plate which has a thickness in the left-right direction. The right wall part  97  extends in the front-rear direction and the up-down direction. The right wall part  97  connects a location in the vicinity of a right end part in the rear surface of the front wall part  94  and a location in the vicinity of a right end part in the front surface of the rear wall part  93 . 
     As depicted in  FIGS.  7  to  9   , the rear wall part  93 , the bottom wall part  95  and the front wall part  94  are formed with a plurality of first slits  98  (an example of a “slit”) which extend along the front-rear direction. The plurality of first slits  98  are arranged in the left-right direction with a spacing distance therebetween. In the present embodiment, the plurality of first slits  98  are provided as five first slits  98 . Each of the plurality of first slits  98  extends in the down direction from a substantially intermediate position in the up-down direction of the rear wall part  93 , and reaches up to a rear end edge of the bottom wall part  95 . Each of the plurality of first slits  98  extends in the front direction from the rear end edge of the bottom wall part  95 , and reaches up to the lower end of the front wall part  94 . Each of the plurality of first slits  98  extends in the up direction from the lower end of the front wall part  94 , and reaches up to a substantially intermediate position in the up-down direction of the front wall part  94 . 
     As depicted in  FIG.  8   , a plurality of regulating pieces  99  extending upward from the upper surface of the bottom wall part  95  are formed. The plurality of regulating pieces  99  are arranged so that each of the plurality of first slits  98  is interposed between two pieces of the plurality of regulating pieces  99  in the left-right direction. Two regulating pieces  99  between which a certain first slits  98  is interposed are positioned with equal spacing distances from the certain first slit  98  in the left-right direction. Each of the plurality of regulating pieces  99  has a shape of a flat plate extending in the front-rear direction and the up-down direction. Each of the plurality of regulating pieces  99  extends, in the front-rear direction from the front surface of the rear wall part  93  up to the rear surface of the front wall part  94 . The spacing distance in the left-right direction of each two first regulating pieces  99  between which one of the plurality of first slits  98  is interposed is slightly longer than a length in the axial direction (axial length) of a first rotating shaft  101  of the spur  40 B. 
     Two first supporting pieces  102  extending upward from the upper surface of the bottom wall part  95  are formed between the two regulating pieces  99  between which one of the plurality of first slits  98  are interposed. The two first supporting pieces  102  are positioned with equal spacing distances from the first slit  98  in the left-right direction. Each of the first supporting pieces  102  has a shape of a flat plate extending in the front-rear direction and the up-down direction. Each of the first supporting pieces  102  extends in the front-rear direction from the front surface of the rear wall part  93  up to the rear surface of the front wall part  94 . Each of the first supporting pieces  102  is formed with a second slit  103  which is opened in an upper end of the first supporting piece  102  and which extends in the down direction. The second slit  103  reaches up to a position adjacent to the upper surface of the bottom wall part  95 , from the upper end of the first supporting piece  102 . The second slit  103  is positioned at an intermediate position in the front-rear direction of the first supporting piece  102 . 
     Two second supporting pieces  104  (in  FIG.  8   , the reference numeral “ 104 ” is affixed only to a part of the second supporting pieces  104 ) extending upward from the upper surface of the bottom wall part  95  are formed between each two first supporting pieces  102  between which one of the plurality of first slits  98  is interposed. The two second supporting pieces  104  face each other, in the left-right direction, with equal spacing distances from the first slit  98  in the left-right direction. Each of the second supporting pieces  104  has a shape of a flat plate extending in the front-rear direction and the up-down direction. Each of the second supporting pieces  104  extends in the front-rear direction from the front surface of the rear wall part  93  up to the rear surface of the front wall part  94 . Each of the second supporting pieces  104  extends upward to a location above the first supporting pieces  102 . A spacing distance between each two second supporting pieces  104  between which one of the plurality of first slits  98  is interposed is slightly longer than an axial length of a rotating part  105   a  of the spur cleaner  105 . Each of the second supporting pieces  104  is formed with a third slit  106  which is opened in an upper end of the second supporting piece  104  and which extends in the down direction. The third slit  106  extends from the upper end of each of the second supporting pieces  104  and reaches up to the upper surface of the bottom wall part  95 . The second slit  106  is positioned at an intermediate position in the front-rear direction of each of the second supporting pieces  104 . 
     As depicted in  FIGS.  7  and  8   , the lid part  74   b  has a shape of a flat plate which has a thickness in the up-down direction. The lid part  74   b  extends in the front-rear direction and the left-right direction. An upper surface and a lower surface of the lid part  74   b  have a rectangular shape which is longer in the left-right direction than in the front-rear direction. The lid part  74   b  faces the bottom wall part  95  in the up-down direction. The lid part  74   b  closes a space between the upper end  93   a  of the rear wall part  93  and the upper end  94   a  of the front wall part  94 . Namely, the lid part  74   b  closes an opening of the body part  74   a.  The lid part  74   b  is fixed to the body part  74   a  by a plurality of screws  107  which are arranged in the left-right direction with a spacing distance therebetween. The lid part  74   b  is formed with a plurality of ribs  108  which extend from the lower surface of the lid part  74   b  in the down direction. The plurality of ribs  108  are arranged in the left-right direction, with a spacing distance therebetween. In the present embodiment, the plurality of ribs  108  includes two first ribs  108   a  of which forward end parts are formed to have a bifurcated shape so as to avoid the regulating piece  99 , and six second ribs  108   b  of which thickness in the left-right direction is smaller than that of the first rib  108   a.    
     As depicted in  FIGS.  4  and  8   , a length L 3  in the up-down direction (an example of a “crossing direction”) between an upper end  74   bb  of the lid part  74   b  and a lower end  95   a  of the bottom wall part  95  is longer than a length L 4  in the up-down direction between an upper end  25   a  and a lower end  25   b  of the CIS  25 . The upper end  74   bb  of the lid part  74   b  is positioned above the upper end  25   a  of the CIS  25 . The lower end  95   a  of the bottom wall part  95  is positioned below the lower end  25   b  of the CIS  25 . 
     The spurs  40 B and the spur cleaners  105  are incorporated into the first spur holder  74 . Each of the spurs  40 B is in a state of being projecting (protruding) to the outside of the rear wall part  93 , the bottom wall part  95  and the front wall part  94  via one of the plurality of slits  98 , and the first rotating shaft  101  is rotatably supported by the two first supporting pieces  102  and the two second supporting pieces  104 . The position of each of the spurs  40 B is determined in the left-right direction by positioning both ends in the axial direction of the first rotating shaft  101  adjacent to the two regulating pieces  99  between which one of the plurality of first slits  98  is interposed. 
     A second rotating shaft  105   b  of each of the plurality of spur cleaners  105  is rotatably supported by the two supporting pieces  104 . The position of each of the plurality of spur cleaners  105  is determined in the left-right direction by positioning end surfaces in the axial direction of the rotating part  105   a  adjacent to the two supporting pieces  104 . By the lid part  74   b  being fixed to the body part  74   a  by the plurality of screws  107 , the spurs  40 B and the plurality of spur cleaners  105  are prevented, by the lid part  74   b,  from being detached or falling out from the inside of the first spur holder  74 , and there is provided a state that forward end parts of the plurality of ribs  108  make contact with the first rotating shaft  101  of each of the spurs  40 B from thereabove, thereby determining the position of the spurs  40 B in the up-down direction. 
     As depicted in  FIGS.  4  and  7   , the second spur holder  75  is positioned in front of the first spur holder  74  at a spacing distance. The second spur holder  75  holds the spurs  72 B. The second spur holder  75  has a configuration which is substantially similar to that of the first spur holder  74 . Accordingly, in the second spur holder  75 , a same reference numeral is affixed to an element corresponding to that in the first spur holder  74 , and any overlapping explanation therefor will be omitted. 
     The first connecting member  76  has a shape of a flat plate which has a thickness in the up-down direction. The first connecting member  76  spreads in the front-rear direction and the left-right direction. An upper surface and a lower surface of the first connecting member  76  each have a rectangular shape which is longer in the front-rear direction than in the left-right direction. The first connecting member  76  connects a left end part of the first spur holder  74  and a left end part of the second spur holder  75 . Specifically, the first connecting member  76  connects a front end edge of the bottom wall part  95  of the first spur holder  74  and a rear end edge of the bottom wall part  95  of the second spur holder  75 . 
     The second connecting member  77  has a shape which is similar to that of the first connecting member  76 . The second connecting member  77  connects a right end part of the first spur holder  74  and a right end part of the second spur holder  75 . Specifically, the second connecting member  77  connects the front end edge of the bottom wall part  95  of the first spur holder  74  and the rear end edge of the bottom wall part  95  of the second spur holder  75 . 
     The first fitting part  91  is arranged in the first spur holder  74 . The first fitting part  91  is positioned in the rear surface of the rear wall part  93  of the first spur holder  74 . The first fitting part  91  has a central fitting part  91   a  arranged in a central part in the left-right direction of the rear surface of the rear wall part  93  and both end fitting parts  91   b  arranged, respectively, in both end parts in the left-right direction of the rear surface of the rear wall part  93 . 
     The central fitting part  91   a  has a first projecting part  111  which is arranged in the center in the left-right direction in the rear surface of the rear wall part  93 , and two second projecting parts  112  each of which is arranged at a spacing distance, in the left-right direction, from the first projecting part  111  in the rear surface of the rear wall part  93 . The first projecting part  111  extends in the rear direction from an upper end part of the rear surface of the rear wall part  93 . The first projecting part  111  is formed to have a shape which is substantially of a letter “U” which is oriented in the down direction as seen from the front direction. Each of the two second projecting parts  112  extends, in the rear surface of the rear wall part  93 , in the rear direction from a position below a lower end of the first projecting part  111 . Each of the two second projecting parts  112  has a flat plate part  112   a  extending in the front-rear direction and the left-right direction, and circular arc parts  112   b  which are formed, respectively, in both edges in the left-right direction of the flat plate part  112   a.  The circular arc parts  112   b  are formed to have a circular arc shape along the outer circumferential surface of the first shaft  84 . As depicted in  FIG.  9   , a spacing distance L 1  between the lower end of the first projecting part  111  and the upper surface of the flat plate part  112   a  is slightly shorter than the diameter of the first shaft  84 . 
     As depicted in  FIG.  7   , the both end fitting parts  91   b  have first fitting pieces  113  which are positioned, respectively, at both end edges in the left-right direction in the rear surface of the rear wall part  93 , and second fitting pieces  114  each of which is positioned at a spacing distance in the left-right direction from one of the first fitting pieces  113 . The first fitting pieces  113  extend in the rear direction from a lower end part of the rear surface of the rear wall part  93 . Each of the first fitting pieces  113  extends in the front-rear direction and the up-down direction. An upper edge of each of the first fitting pieces  113  is formed to have a circular arc shape along the outer circumferential surface of the first shaft  84 . The second fitting pieces  114  extend in the rear direction from the upper end part of the rear surface of the rear wall part  93 . Each of the second fitting pieces  114  extends in the front-rear direction and the up-down direction. A lower edge of each of the second fitting pieces  114  is formed to have a circular arc shape along the outer circumferential surface of the first shaft  84 . A spacing distance in the up-down direction between the upper edge of each of the first fitting pieces  113  and the lower edge of one of the second fitting pieces  114  is equal to the spacing distance L 1  in the up-down direction between the lower end of the first projecting part  111  and the upper surface of the flat plate part  112   a . Namely, the spacing distance in the up-down direction between the upper edge of each of the first fitting pieces  113  and the lower edge of one of the second fitting pieces  114  is slightly shorter than the diameter of the first shaft  84 . Note that one of the both end fitting parts  91   b  and the central fitting part  91   a  may be omitted. 
     As depicted in  FIGS.  7  and  10   , the second fitting parts  92  are arranged in the second spur holder  75 . The second fitting parts  92  are positioned in the front surface of the front wall part  94  of the second spur holder  75 . The second fitting parts  92  are arranged, in a central part and in both end parts in the left-right direction in the front surface of the front wall part  94 . Each of the second fitting parts  92  has a plurality of third fitting pieces  92   a,  a connecting piece  92   b  and a third projecting part  92   c.    
     The plurality of third fitting pieces  92   a  are formed in the front surface of the front wall part  94  with a spacing distance therebetween in the left-right direction. The plurality of third fitting pieces  92   a  extend in the front direction from the front surface of the front wall part  94 . The plurality of third fitting pieces  92   a  extend in the front-rear direction and the up-down direction. An upper edge of each of the plurality of third fitting pieces  92   a  is formed to have a shape which is substantially of a letter “U” as seen from the left-right direction (see  FIG.  9   ). The connecting piece  92   b  connects front end edges of third fitting pieces  92   a  which are adjacent to each other in the left-right direction. Each of the plurality of third projecting parts  92   c  projects in the front direction from the upper part of the front surface of the front wall part  94 . Each of the plurality of third projecting parts  92   c  is positioned between the third fitting pieces  92   a  which are adjacent to each other in the left-right direction. As depicted in  FIG.  9   , a spacing distance L 2  in the front-rear direction between a front end edge of the third fitting part  92   c  and the upper edge of the third fitting piece  92   a  is slightly shorter than the diameter of the second shaft  85 . 
     Note that although each of the second fitting parts  92  at the both ends has two piece of the third fitting piece  92   a  and the second fitting part  92  at the central part has four pieces of the third fitting piece  92   a,  it is allowable that each of the second fitting parts has not less than 1 (one) piece of the third fitting piece  92   a.  Further, it is allowable to omit one of the second fitting part  92  at the central part and the second fitting parts  92  at the both end parts. 
     The holding member  73  configured as described above is attached and detached with respect to the supporting frame  83  via the first shaft  84  and the second shaft  85 , in the following manner. 
     First, the user fits the first shaft  84  to the first fitting part  91 . Specifically, the user fits the first shaft  84  to the central fitting part  91   a  against an elastic force of each of the first projecting part  111  and the two second projecting parts  112 , and fits the first shaft  84  to the both end fitting parts  91   b  against an elastic force of each of the first projecting pieces  113  and the second projecting pieces  114 . 
     Next, the user fits the second shaft  85  to the second fitting parts  92 . Specifically, first, the user rotates the holding member  73  in the up direction up to a position at which the holding member  73  approaches closely to the second shaft  85 , with the first shaft  84  fitted to the first fitting part  91  as the center of rotation. Next, the user fits the second shaft  85  to the second fitting parts  92  against the elastic force of each of the plurality of third projecting parts  92   c  and the plurality of third fitting pieces  92   a.  With this, there is provided a state that the plurality of third projecting parts  92   c  make contact with the upper side of the second shaft  85 , thereby preventing the occurrence of such a situation that the second shaft  85  is detached from the second fitting parts  92  in the up direction. In such a manner, the holding member  73  is attached to the supporting frame  83  via the first shaft  84  and the second shaft  85 . 
     On the other hand, for example, in a case that the holding member  73  is to be detached from the first shaft  84  and the second shaft  85  in order to exchange the spur cleaners  105 , the detaching is performed in a reverse procedure to that as described above. The user detaches the holding member  73  from the first shaft  84  and the second shaft  85 , and then the user detaches the lid part  74   b  of each of the first spur holder  74  and the second spur holder  75  from the body part  74   a,  thereby making it possible to easily exchange the spur cleaners  105 . 
     Next, an operation of the image recording apparatus  10  will be explained. 
     In a case that the conveying roller  36 A of the conveying roller pair  36  rotates, the sheet S is drawn in the up direction from the roll body  37  in the sheet accommodating space  30 C, via the gap  42 . The sheet S drawn from the roll body  37  is conveyed in the front direction while being nipped between the conveying roller  36 A and the pinch roller  36 B. The sheet S conveyed in the front direction by the conveying roller pair  36  is supported by the supporting part  118  of the supporting mechanism  116 . In this situation, the ink is discharged downward from the plurality of nozzles  38 A of the recording head  38  to thereby record an image on the upper surface of the sheet S. The sheet S having the image recorded on the upper surface thereof is conveyed in the front direction by the conveying belt  117 . 
     The sheet S which is (being) conveyed in the front direction by the conveying belt  117  is supported by the upper surface of the metallic plate  39   a  of the fixing part  39 . While the sheet S is passing on the metallic plate  39   a,  the sheet S and the ink are heated by the heat of the metallic plate  39   a.  With this, the thermoplastic resin fine particles included in the ink are melted, and then are subjected to cooling thereafter to thereby cure or harden the molten thermoplastic resin fine particles, thereby fixing the pigment included in the ink to the sheet S. In this situation, a part of the heat of the metallic plate  39   a  is radiated toward the CIS  25 , but the first spur holder  74  positioned between the CIS  25  and the fixing part  39  functions as a heat shielding wall. Accordingly, the heat of the metallic plate  39   a  is less likely to be transmitted to the CIS  25 . 
     The sheet S heated in the fixing part  39  is conveyed in the front direction while being nipped between the discharging roller  40 A and the spurs  40 B of the first discharging roller pair  40 . In this situation, the ink adhered to the spurs  40 B is removed by the plurality of spur cleaners  105  making contact with the spurs  40 B, respectively, and rotating following the rotation of the spurs  40 B. The sheet S which is (being) conveyed in the front direction by the first discharging roller pair  40  is supported by the supporting member  46 . In a case that the sheet S is supported by the supporting member  46 , the CIS  25  radiates the light from the light source toward the upper surface (recording surface) of the sheet S, and outputs an electric signal in accordance with the intensity of a reflected light of the light reflected off (by) the sheet S. With this, the image of the upper surface (recording surface) of the sheet S is read by the CIS  25 . 
     The sheet S of which image has been read by the CIS  25  is conveyed in the front direction by the second discharging roller pair  72 . The sheet S which is conveyed in the front direction by the second discharging roller pair  72  is cut along the left-right direction by the cutter unit  26  in a state that a front part of the sheet S is exposed from the discharge port  33  to the outside of the casing  30 . The sheet S cut by the cutter unit  26  is discharged from the discharge port  33 . 
     Effect of Embodiment 
     In the image recording apparatus  10 , since the both ends in the up-down direction of the first spur holder  74  are positioned at the outside of the both ends in the up-down direction of the CIS  25 , the first spur holder  74  is likely to function as the heat shielding wall with respect to the radiation heat of the fixing part  39 . Accordingly, the radiation heat of the fixing part  39  is less likely to reach the CIS  25 , thereby making it possible to sufficiently suppress the occurrence of any unsatisfactory reading by the CIS  25 . 
     In the image recording apparatus  10 , since the two walls, which are the rear wall part  93  and the front wall part  94  of the first spur holder  74  function as the heat shielding wall with respect to the radiation heat of the fixing part  39 , the radiation heat of the fixing part  39  is less likely to reach the CIS  25 . 
     In the image recording apparatus  10 , since the rear wall part  93  and the front wall part  94  of the first spur holder  74  extend in the left-right direction, the rear wall part  93  and the front wall part  94  of the first spur holder  74  are likely to function as the heat shielding wall with respect to the radiation heat of the fixing part  39 . Accordingly, the radiation heat of the fixing part  39  is less likely to reach the CIS  25 . 
     In the image recording apparatus  10 , since an air layer (air cavity) surrounded by the rear wall part  93 , the front wall part  94 , the bottom wall part  95  and the lid part  74   b  is formed or defined in the first spur holder  74 , the radiation heat of the fixing part  39  is less likely to be transmitted to the first spur holder  74 . Accordingly, since the first spur holder  74  is likely to function as the heat shielding wall with respect to the radiation heat of the fixing part  39 , the radiation heat of the fixing part  39  is less likely to reach the CIS  25 . 
     In the image recording apparatus  10 , since a part of each of the spurs  40 B protrudes to the outside of the bottom wall part  95  via one of the plurality of first slits  98  formed in the bottom wall part  95 , it is possible, in the first spur holder  74 , to cause the spurs  40 B to make contact with the recording surface (upper surface) of the sheet S, while retaining the air layer which is surrounded by the rear wall part  93 , the front wall part  94 , the bottom wall part  95  and the lid part  74   b  in the first spur holder  74 . 
     In the image recording apparatus  10 , since the plurality of spur cleaners  105  which make contact, respectively, with the spurs  40 B are positioned between the rear wall part  93  and the front wall part  94  of the first spur holder  74 , it is possible to remove the ink adhered to the spurs  40 B by the plurality of spur cleaners  105 . 
     In the image recording apparatus  10 , since the user is capable of detaching the first spur holder  74  from the supporting frame  83  via the first shaft  84 , it is possible to easily exchange the spur cleaners  105 . 
     In the image recording apparatus  10 , since the both ends in the left-right direction,  56  of the rear wall part  93  of the first spur holder  74  are positioned at the outside, respectively, of the both ends in the left-right direction of the fixing part  39 , the rear wall part  93  of the first spur holder  74  is likely to function as the heat shielding wall with respect to the radiation heat of the fixing part  39 . Accordingly, the radiation heat of the fixing part  39  is less likely to reach the CIS  25 . 
     While the invention has been described in conjunction with various example structures outlined above and illustrated in the figures, various alternatives, modifications, variations, improvements, and/or substantial equivalents, whether known or that may be presently unforeseen, may become apparent to those having at least ordinary skill in the art. Accordingly, the example embodiments of the disclosure, as set forth above, are intended to be illustrative of the invention, and not limiting the invention. Various changes may be made without departing from the spirit and scope of the disclosure. Therefore, the disclosure is intended to embrace all known or later developed alternatives, modifications, variations, improvements, and/or substantial equivalents. Some specific examples of potential alternatives, modifications, or variations in the described invention are provided below. 
     Modification 
     In the image recording apparatus  10 , although the fixing part  39  which is configured to fix the ink to the sheet S heats the sheet S and the ink, it is sufficient that the fixing part  39  heats at least one of the ink and the sheet S (that is, the ink and/or the sheet S). In such a case, it is allowable, for example, that the fixing part is configured to heat the sheet S in advance, and to cause the ink to fix to the sheet S by the residual heat of the pre-heating. 
     In the image recording apparatus  10 , although the first spur holder  74  and the second spurt holder  75  are connected to each other by the first connecting member  76  and the second connecting member  77 , it is allowable that the first spur holder  74  and the second spurt holder  75  are not connected to each other. Namely, it is allowable that the first spur holder  74  and the second spurt holder  75  are separated from each other. 
     In the image recording apparatus  10 , although the first spur holder  74  and the second spurt holder  75  are configured to be detachably attachable, via the first shaft  84  and the second shaft  85 , with respect to the supporting frame  83  which is fixed to the inner wall surface of the upper casing  31 , it is allowable that the first spur holder  74  and the second spurt holder  75  are configured to be detachably attachable with respect to the side frames  20 ,  21  which are fixed to the lower casing  32 . In such a case, the first shaft  84  and the second shaft  85  are fixed to the side frames  20 ,  21 . 
     In the above-described embodiment, it is allowable to use a CCD camera, instead of using the CIS  25 . The CCD camera is another example of the “reader”.