Patent Publication Number: US-2022234857-A1

Title: Medium transport apparatus

Description:
The present application is based on, and claims priority from JP Application Serial Number 2021-011756, filed Jan. 28, 2021, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a medium transport apparatus. 
     2. Related Art 
     In a sheet transport apparatus in JP-A-2017-53930, an opening/closing door locks against an apparatus main body when a hook member horizontally provided at the opening/closing door engages with a hook shaft provided at the apparatus main body. A contact surface of the hook member to come into contact with the hook shaft extends vertically. 
     In the sheet transport apparatus in JP-A-2017-53930, to bring such a vertically-extending contact surface into contact with the hook shaft, the hook member needs an excess overstroke from the point the hook member goes beyond the hook shaft to the point the hook member comes into contact with the hook shaft. 
     In a configuration in which an apparatus main body is closed by a closing operation of a door, when there are members that are brought into engagement by the closing operation of the door other than a lock mechanism section, the overstroke closing operation performed to lock the door may cause those members in engagement to interfere with each other. 
     SUMMARY 
     To solve the above-described problem, a medium transport apparatus according to the present disclosure includes: an apparatus main body in which a medium is transported; a door coupled to the apparatus main body and configured to rotate about a rotation axis and switch between an open state and a closed state; a plurality of rotating bodies configured to be away from each other in the open state and to be in contact with each other and transmit a drive force in the closed state; and a lock mechanism section that locks the door against the apparatus main body to bring the door into the closed state and unlocks the door from the apparatus main body to bring the door into the open state. The lock mechanism section includes a counter-engagement portion extending in a first direction, an engagement portion having an engagement surface configured to change in position between a first posture and a second posture in a second direction intersecting with the first direction and engage with the counter-engagement portion, and an application member that applies a force to the engagement portion to enable the engagement surface to change in position from the first posture to the second posture. In a closing operation of the door, the engagement surface changes in position from the first posture to the second posture while shifting a position of contact with the counter-engagement portion, and in the closing operation and in the closed state, the engagement surface applies, to the counter-engagement portion, a pull-in force for moving the door to a closed position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram showing an internal configuration of a printer according to an embodiment. 
         FIG. 2  is a perspective view showing the overall configuration of the printer according to the embodiment. 
         FIG. 3  is a front view showing an inner door unit of the printer according to the embodiment. 
         FIG. 4  is a perspective view showing how pinch rollers and rubber rollers are in contact with each other in the printer according to the embodiment. 
         FIG. 5  is a perspective view showing how a main body gear and a gear of a gear section mesh with each other in the printer according to the embodiment. 
         FIG. 6  is a perspective view showing how the gear section and a main body bracket are in contact with each other in the printer according to the embodiment. 
         FIG. 7  is a perspective view showing a state where the gear section is decoupled from the main body bracket in the printer according to the embodiment. 
         FIG. 8  is a vertical sectional view of an inner door unit in the printer according to the embodiment, seen from the side. 
         FIG. 9  is a side view of a lock lever in the printer according to the embodiment. 
         FIG. 10  is a perspective view showing a state where the inner door unit abuts against the main body bracket in the printer according to the embodiment. 
         FIG. 11  is a perspective view showing the arrangement of the lock lever and a support bracket in the printer according to the embodiment. 
         FIG. 12A  is a schematic diagram showing a state where an anterior surface of the lock lever is in contact with a counter-engagement shaft in the printer according to the embodiment. 
         FIG. 12B  is a schematic diagram showing a state where the lock lever is climbing over the counter-engagement shaft in the printer according to the embodiment. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     An overview of the present disclosure is described below. 
     A medium transport apparatus of a first aspect includes: an apparatus main body in which a medium is transported; a door coupled to the apparatus main body and configured to rotate about a rotation axis and switch between an open state and a closed state; a plurality of rotating bodies configured to be away from each other in the open state and to be in contact with each other and transmit a drive force in the closed state; and a lock mechanism section that locks the door against the apparatus main body to bring the door into the closed state and unlocks the door from the apparatus main body to bring the door into the open state. The lock mechanism section includes a counter-engagement portion extending in a first direction, an engagement portion having an engagement surface configured to change in position between a first posture and a second posture in a second direction intersecting with the first direction and engage with the counter-engagement portion, and an application member that applies a force to the engagement portion to enable the engagement surface to change in position from the first posture to the second posture. In a closing operation of the door, the engagement surface changes in position from the first posture to the second posture while shifting a position of contact with the counter-engagement portion, and in the closing operation and in the closed state, the engagement surface applies, to the counter-engagement portion, a pull-in force for moving the door to a closed position. 
     According to this aspect, when the door is operated from the open position into the closed position, the engagement surface comes into contact with the counter-engagement portion. As the door approaches the closed position, the engagement surface changes its posture from the first posture to the second posture. The engagement surface changes its posture from the first posture to the second posture while shifting the position of contact with the counter-engagement surface. In other words, the engagement surface changes its posture with the engagement surface and the counter-engagement portion staying in contact with each other. Thus, there is no need for the engagement portion to overstroke. 
     Also, the elimination of the need for the overstroke of the engagement portion allows reduction in the interference between the plurality of rotating bodies. 
     In a medium transport apparatus of a second aspect according to the first aspect, the engagement portion has a central axis of rotation relative to the door. 
     According to this aspect, the central axis of rotation of the engagement portion is immobile. Thus, compared to a configuration in which the whole engagement portion slides, the mechanism for moving the engagement portion can be simplified. 
     In a medium transport apparatus of a third aspect according to the second aspect, the engagement portion includes an anterior surface that comes into contact with the counter-engagement portion before the engagement surface does when a state of the door switches from the open state to the closed state, and when the anterior surface is in contact with the counter-engagement portion, the engagement portion receives, from the counter-engagement portion, a reactive force in a rotational direction in which the engagement surface is moved from the second posture to the first posture. 
     According to this aspect, because the anterior surface comes into contact with the counter-engagement portion, the engagement surface and the counter-engagement portion transition into a contacting state after the engagement portion is rotated in a direction in which the engagement surface is moved from the second posture to the first posture. In other words, the engagement portion can easily rotate before the engagement surface and the counter-engagement shaft come into contact with each other, which makes it easy for the engagement surface and the counter-engagement portion to transition into a contacting state. 
     In a medium transport apparatus of a fourth aspect according to the second or third aspect, in the closed state, the central axis of rotation is orthogonal to the rotation axis. 
     According to this aspect, when the door is moved from the open state to the closed state, the area of contact between the engagement surface and the counter-engagement portion gradually increases, and also the friction force acting on the engagement surface gradually increases in comparison to the configuration in which the engagement portion slides. Thus, a feel of jerkiness felt when the door is brought into the closed state can be reduced. 
     In a medium transport apparatus of a fifth aspect according to the second to fourth aspects, in the closed state, the position of contact between the engagement surface and the counter-engagement portion is located lower than the central axis of rotation in an apparatus height direction. 
     According to this aspect, the center of rotation of the engagement portion is located higher than the position of contact between the engagement surface and the counter-engagement portion in the apparatus height direction. This makes it easier for the engagement surface to move away from the counter-engagement portion at the time of unlocking and thus makes unlocking easier. 
     In a medium transport apparatus of a sixth aspect according to the second to fifth aspects, the engagement portion is provided at one of the apparatus main body and the door, the counter-engagement portion and a restriction portion that restricts movement of the door are provided at another of the apparatus main body and the door, and in the closed state, the counter-engagement portion is at a position overlapping with the restriction portion in an apparatus height direction. 
     According to this aspect, the restriction portion restricts the movement of the door in the closed state. Since the engagement portion is at a position overlapping with the restriction portion in the apparatus height direction, the position of contact between the engagement surface and the counter-engagement portion and the position where the restriction portion restricts the door are closely disposed. This helps prevent overstroke operation of the door when the engagement surface and the counter-engagement portion come into contact with each other. 
     In a medium transport apparatus of a seventh aspect according to the second to sixth aspects, when seen in an axial direction of the central axis of rotation, the engagement surface in the second posture extends to both sides of the position of contact with the counter-engagement portion. 
     According to this aspect, even if the position of contact between the engagement surface and the counter-engagement portion is displaced, the engagement surface and the counter-engagement portion can be brought into contact with each other because the engagement surface extends to both sides of the position of contact. 
     In a medium transport apparatus of a eighth aspect according to the seventh aspect, the engagement surface is a slanted surface extending in an intersecting direction intersecting with an apparatus height direction, and an angle formed between the apparatus height direction and the intersecting direction is greater than 0° and smaller than 45°. 
     According to this aspect, regarding the force acting on the position of contact between the engagement surface and the counter-engagement portion, a component force in a horizontal direction orthogonal to the apparatus height direction is large compared to a configuration in which the angle formed between the apparatus height direction and the intersecting direction exceeds 45°. Thus, it is easier to obtain a pull-in force exerted when the engagement portion comes into contact with the counter-engagement portion. 
     In a medium transport apparatus of a ninth aspect according to the first to eighth aspects, an outer door is provided to the apparatus main body outward of the door, the outer door is rotatably coupled to the apparatus main body and is thereby configured to switch between an opening state and a closing state, and in the closing state, the outer door presses the door in the closed state against the apparatus main body. 
     According to this aspect, the outer door presses the door in the closed state against the apparatus main body, thereby restricting the door from moving to the open position. Thus, the door can stay in the closed state. 
     In a medium transport apparatus of a tenth aspect according to the ninth aspect, one of the door and the outer door is provided with a rotatable roller and an elastically deformable press member that presses the roller toward another of the door and the outer door, and the other of the door and the outer door has a contact portion that comes into contact with the roller. 
     According to this aspect, the roller is pressed against the contact portion by receiving a pressing force from the press member while in contact with the contact portion. Even if the outer door is operated to overstroke relative to the door, the press member elastically deforms and thereby absorbs the pressing force that the contact portion exerts to the roller. Thus, deformation of the roller can be reduced. 
     In a medium transport apparatus of a eleventh aspect according to the tenth aspect, a first transport path along which the medium is transported is formed between the apparatus main body and the door, and a second transport path along which the medium is transported by rotation of the roller is formed between the door and the outer door. 
     According to this aspect, even if the medium is jammed during transport, opening the door or the outer door makes it possible to remove the medium and therefore unlikely for the medium to remain in the first transport path or the second transport path. 
     A medium transport apparatus of a twelfth aspect according to the eleventh aspect further includes a recording section that performs recording on the medium transported thereto. 
     According to this aspect, the recording section performs recording on the medium transported thereto. Even if the recorded medium is jammed during transport, opening the door or the outer door makes it possible to remove the recorded medium and therefore unlikely for the recorded medium to remain in the first transport path or the second transport path. 
     Hereinbelow, a specific description is given of a printer  10  as an example of the medium transport apparatus according to the present disclosure. 
     As shown in  FIGS. 1 and 2 , the printer  10  is configured as an ink jet recording apparatus that performs recording on a sheet P as an example of the medium by ejecting ink Q as an example of the liquid thereto. Note that the X-Y-Z coordinate system shown in the drawings is a Cartesian coordinate system. 
     The X-direction is an apparatus width direction as seen from an operator of the printer  10 , and is a horizontal direction. A leftward direction of the X-direction is a +X-direction, and a rightward direction of the X-direction is a −X-direction. 
     The Y-direction is a width direction intersecting with a direction in which the sheet P is transported and is also an apparatus depth direction. The Y-direction is also a horizontal direction. A direction of the Y-direction toward an operator of the printer  10  is a +Y-direction, and a direction of the Y-direction away from the operator is a −Y-direction. 
     The Z-direction is an example of the apparatus height direction and is a vertical direction. An upward direction of the Z-direction is a +Z-direction, and a downward direction of the Z-direction is a −Z-direction. 
     In the printer  10 , a sheet P is transported travelling along a transport path T shown with a dot-dash line. Note that the direction in which a sheet P is transported is along the transport path T and is therefore different for each section of the transport path T. 
     The printer  10  includes, by way of example, an apparatus main body  12 , an ink tank  27 , a line head  28 , a controller  29 , an outer door unit  30 , a rotation section  40  ( FIG. 5 ), an inner door unit  60 , and a lock mechanism section  100  ( FIG. 3 ). 
     The apparatus main body  12  includes a casing forming the contour. A discharge section  13  including a space where a recorded sheet P is discharged is formed on the +Z-direction side of the Z-direction center of the apparatus main body  12 . The apparatus main body  12  is also provided with a sheet cassette  15  for housing sheets P. An opening portion  12 A opening in the X-direction is formed at a −X-direction end portion of the apparatus main body  12 . When the opening portion  12 A is open, part of the transport path T is exposed. 
     The apparatus main body  12  is configured including a main body frame  14  which is a framework member and a main body bracket  45  ( FIG. 6 ) to be described later which is fixed to the main body frame  14 . In the apparatus main body  12 , a sheet P is transported along the transport path T. 
     A sheet P housed in the sheet cassette  15  is transported along the transport path T along which a pickup roller  16 , transport roller pairs  17 ,  18 , and the like are disposed. Also disposed along the transport path T are two pulleys  21 , a transport belt  22  looped around the two pulleys  21 , a plurality of transport roller pairs  24  that transport the sheet P, a plurality of flaps  25  that switch the paths to which the sheet P is transported, and the like. 
     The transport belt  22  faces the line head  28 . 
     The transport roller pairs  24  each have a transport roller  24 A disposed on the −X-direction side of the path and a transport roller  24 B disposed on the +X-direction side of the path. 
     The transport path T is, specifically, configured including a main transport path T 1 , discharge paths T 2 , T 3 , a feed-in path T 4 , a switch-back path T 5 , and a feed-out path T 6 . 
     The main transport path T 1  extends from the sheet cassette  15  to the position facing the line head  28 . 
     The discharge path T 2  is formed between the apparatus main body  12  and the inner door unit  60  to be described later and extends from the downstream end of the main transport path T 1  to the discharge section  13 . Also, the discharge path T 2  is an example of the first transport path and is a path along which the sheet P is transported. 
     The discharge path T 3  branches off from a midpoint of the discharge path T 2  and extends to the discharge section  13 . 
     The feed-in path T 4  is a path along which the sheet P is fed from the main transport path T 1  into the switch-back path T 5  described below. 
     The switch-back path T 5  extends in, by way of example, the +Z-direction. Along the switch-back path T 5 , the sheet P is transported in the +Z-direction and in the −Z-direction in a switch-back manner. 
     The feed-out path T 6  is a path along which the sheet P is fed out of the switch-back path T 5  and which is coupled to the main transport path T 1 . 
     The feed-in path T 4  and the switch-back path T 5  are an example of the second transport path and are formed between the inner door unit  60  and the outer door unit  30  to be described later. Also, along the switch-back path T 5 , the sheet P is transported by rotation of rubber rollers  36  and pinch rollers  94  to be described later. 
     The line head  28  is an example of the recording section, and performs recording by ejecting ink Q supplied from the ink tank  27  to the sheet P transported thereto. 
     The controller  29  is configured including a central processing unit (CPU), a read-only memory (ROM), a random-access memory (RAM), and a storage (none of which is shown), and controls transport of the sheet P and operation of the sections of the printer  10 , including the line head  28 . 
     As shown in  FIG. 2 , the outer door unit  30  is an example of the outer door and is provided to the apparatus main body  12  at its −X-direction side, which is outward of the inner door unit  60  to be described later. The outer door unit  30  is rotatably coupled to the apparatus main body  12  by a hinge section  32 . 
     The hinge section  32  is provided at a −Y-direction end portion of the main body frame  14 . The hinge section  32  has a rotation axis (not shown) extending in the Z-direction. 
     By being rotated about the rotation axis of the hinge section  32 , the outer door unit  30  can be switched between an opening state of opening the opening portion  12 A and a closing state of closing the opening portion  12 A. Further, in the closing state, the outer door unit  30  pushes the inner door unit  60  which is in a closed state in the +X-direction against the apparatus main body  12 . 
     The outer door unit  30  is configured by including, by way of example, an outer cover  34  and an outer frame  35 . 
     The outer cover  34  is formed in a plate shape with a predetermined thickness and is sized to be able to close the opening portion  12 A. 
     The outer frame  35  is attached to the surface of the outer cover  34  that faces the opening portion  12 A. The outer frame  35  has a lower portion  35 A, a center portion  35 B, and an upper portion  35 C. 
     The lower portion  35 A forms a portion of the outer frame  35  which is on the −Z-direction side of the Z-direction center of the outer frame  35  and includes therein the feed-out path T 6 . 
     The center portion  35 B forms a Z-direction center portion of the outer frame  35 , and forms the feed-in path T 4  together with the inner door unit  60  to be described later. 
     The upper portion  35 C forms a portion of the outer frame  35  which is on the +Z-direction side of the Z-direction center of the outer frame  35 , and forms the switch-back path T 5  together with the inner door unit  60 . At the upper portion  35 C, the rubber rollers  36  ( FIG. 1 ) are provided. In other words, the outer door unit  30  has the rubber rollers  36 . 
     As shown in  FIG. 4 , the rubber rollers  36  are an example of the contact portion and are provided at the upper portion  35 C of the outer frame  35 . The rubber rollers  36  each have a columnar shaft portion  37  extending in the Y-direction and wider diameter portions  38  provided at the shaft portion  37  with a space therebetween in the Y-direction and increased in diameter in the radial direction of the shaft portion  37 . The wider diameter portions  38  are made of a rubber member formed in a tubular shape. An outer circumferential surface  38 A of the wider diameter portion  38  protrudes from the outer frame  35  in the +X-direction. 
     In the closing state in which the outer door unit  30  closes the opening portion  12 A ( FIG. 1 ), part of the outer circumferential surface  38 A is in contact with the pinch roller  94  to be described later. 
     As shown in  FIG. 5 , the rotation section  40  has, by way of example, a main body gear  42  and a transmission gear  44 . 
     The main body gear  42  and the transmission gear  44  are an example of the plurality of rotating bodies. The main body gear  42  and the transmission gear  44  are away from each other when the inner door unit  60  to be described later is in an open state, and come into contact with each other and become able to transmit a drive force when the inner door unit  60  is in the closed state. 
     The main body gear  42  is supported by a bracket (not shown) provided at the apparatus main body  12  ( FIG. 2 ) in a manner rotatable about its axis extending in the Y-direction. A drive force is transmitted to the main body gear  42  from a motor (not shown) via a gear  43 . 
     The transmission gear  44  is provided at a gear section  84  to be described later in a manner rotatable about its axis extending in the Y-direction. When the inner door unit  60  is in the closed state, the transmission gear  44  meshes with the main body gear  42  and become able to transmit a drive force. 
     As shown in  FIGS. 6 and 7 , the main body bracket  45  is a member fixed to a +Y-direction end portion of the main body frame  14  ( FIG. 1 ). By way of example, the main body bracket  45  is formed by bending sheet metal and has a vertical wall  46 , a side wall  47 , a side wall  48 , and a projecting portion  52 . The main body bracket  45  is also provided with a first abutment portion  51 , a second abutment portion  54 , a counter-engagement shaft  55 , a damper  56 , and a third abutment portion  58 . 
     The vertical wall  46  is along the Y-Z plane and extends in the Z-direction. The side wall  47  extends in the −X-direction from a −Y-direction end portion of the vertical wall  46 . The side wall  48  extends in the −X-direction from a +Y-direction end portion of the vertical wall  46 . The main body bracket  45  is thus formed in a letter-U shape opening in the −X-direction when seen in the Z-direction. Note that a −X-direction end portion of a part of the side wall  47  which is on the +Z-direction side of the Z-direction center of the side wall  47  is referred to as the first abutment portion  51 . 
     The first abutment portion  51  is an example of the restriction portion, and when the inner door unit  60  is in the closed state, comes into contact with a support shaft portion  74  ( FIG. 7 ) to be described later in the −X-direction, thereby restricting the inner door unit  60  from moving too far in the +X-direction. 
     The projecting portion  52  is a part projecting in the −Y-direction from a +X-direction end portion of a Z-direction center portion of the side wall  47 . The projecting portion  52  is formed in a plate shape having a predetermined thickness in the X-direction. 
     The second abutment portion  54  is a part projecting in the −Y-direction from a +X-direction end portion of a +Z-direction end portion of the side wall  48 . The second abutment portion  54  is located on the +Z-direction side relative to the vertical wall  46  and is formed in a plate shape having a predetermined thickness in the X-direction. The second abutment portion  54  is an example of the restriction portion, and when the inner door unit  60  is brought to the closed state, comes into contact with a counter-abutment portion  92  of a cover member  86  to be described later in the −X-direction, thereby restricting the inner door unit  60  from moving too far in the +X-direction. 
     The counter-engagement shaft  55  is an example of the counter-engagement portion, and is a columnar member which is long in the Y-direction which is an example of the first direction. The counter-engagement shaft  55  is provided at a part of the side wall  47 , the part being on the +Z-direction side of the Z-direction center of the side wall  47  and on the −X-direction side of the X-direction center of the side wall  47 . The counter-engagement shaft  55  extends in the −Y-direction from the side wall  47 . The height position of the counter-engagement shaft  55  in the Z-direction is lower than the height position of the second abutment portion  54  in the Z-direction. Note that the counter-engagement shaft  55  is included in the lock mechanism section  100  to be described later. 
     In the closed state of the inner door unit  60 , the counter-engagement shaft  55  is at a position overlapping with the first abutment portion  51  over the range of a length L 1  ( FIG. 7 ) in the Z-direction. 
     The damper  56  ( FIG. 7 ) is attached to the projecting portion  52  and extends in the −X-direction from the projecting portion  52 . By way of example, the damper  56  has a contact portion  56 A and a spring portion  56 B. The contact portion  56 A is made of, by way of example, a resin member formed in a columnar shape extending in the X-direction. The −X-direction end surface of the contact portion  56 A is a planar surface along the Y-Z plane. The contact portion  56 A is brought into contact with a first restriction plate portion  78  to be described later in the −X-direction. 
     The spring portion  56 B is attached to the projecting portion  52  at one end in the X-direction and is attached to the contact portion  56 A at the other end, thereby being elastically deformable in the X-direction. 
     The height position of the damper  56  in the Z-direction is lower than the height position of the counter-engagement shaft  55  in the Z-direction. 
     The third abutment portion  58  is provided at a −X-direction end portion of a part of the side wall  47  which is on the −Z-direction side of the Z-direction center of the side wall  47 . The third abutment portion  58  is formed in a columnar shape and extends in the −Y-direction from the side wall  47 . The diameter of the third abutment portion  58  is, by way of example, larger than that of the counter-engagement shaft  55 . The length of the third abutment portion  58  in the Y-direction is, by way of example, longer than the length of the counter-engagement shaft  55  in the Y-direction. The height position of the third abutment portion  58  in the Z-direction is lower than the height position of the damper  56  in the Z-direction. 
     The third abutment portion  58  is an example of the restriction portion, and when the inner door unit  60  is brought into the closed state, comes into contact with a guide portion  65  to be described later in the −X-direction, thereby restricting the inner door unit  60  from moving too far in the +X-direction. 
     As shown in  FIG. 3 , the inner door unit  60  is an example of the door, and is a unit coupled to the apparatus main body  12  in a manner rotatable about a rotation axis C 1  and is configured to be switchable between the open state and the closed state. Specifically, the inner door unit  60  is configured including a frame portion  62 , the guide portion  65  ( FIG. 6 ), a rotation shaft  61 , a support bracket  68 , the gear section  84  ( FIG. 5 ), the cover member  86  ( FIG. 7 ), the pinch rollers  94 , and press springs  96  ( FIG. 4 ). Note that in the description of the inner door unit  60 , the positions of its members are described regarding their positions when the inner door unit  60  is in the closed state. 
     The closed state of the inner door unit  60  is a state in which the inner door unit  60  housed in the apparatus main body  12  is locked against the apparatus main body  12  by the lock mechanism section  100  to be described later and is a state in which the inner door unit  60  forms the discharge path T 2  ( FIG. 1 ) together with the apparatus main body  12 . 
     The open state of the inner door unit  60  is a state in which the inner door unit  60  is unlocked from the apparatus main body  12  and a state in which the discharge path T 2  is exposed. 
     The frame portion  62 , as seen in the X-direction, is formed in a rectangular shape whose dimension in the Y-direction is longer than its dimension in the Z-direction. The frame portion  62  is configured including, by way of example, a first frame  63  and a second frame  66 . 
     The first frame  63  forms a −X-direction part of the frame portion  62 . The first frame  63  has a vertical wall  64  extending upright along the Y-Z plane. The vertical wall  64  is provided with the plurality of pinch rollers  94  and the plurality of press springs  96  to be described later. 
     The second frame  66  ( FIG. 6 ) forms a +X-direction part of the frame portion  62 . The second frame  66  has a vertical wall  67  extending upright along the Y-Z plane. The vertical wall  67  is provided with the plurality of transport rollers  24 A ( FIG. 1 ) in such a manner that they are rotatable. 
     As shown in  FIG. 6 , the guide portion  65  is provided at a +Y-direction end portion of the vertical wall  64 . 
     The guide portion  65  has a bottom wall  65 A along the X-Y plane, a side wall  65 B that stands upright in the +Z-direction at a −Y-direction end portion of the bottom wall  65 A, a front wall  65 C that stands upright in the +Z-direction at a −X-direction end portion of the bottom wall  65 A, and an upper wall  65 D that is continuous with the side wall  65 B and the front wall  65 C and is located on the +Z-direction side relative to the bottom wall  65 A. In other words, the guide portion  65  is a chamber portion that is open in both the +X-direction and the +Y-direction. The interval between the bottom wall  65 A and the upper wall  65 D in the Z-direction increases more and more in the +X-direction. 
     The guide portion  65  is sized so that the third abutment portion  58  can be inserted thereto, and guides the third abutment portion  58  in the X-direction. 
     Guided by the guide portion  65 , the third abutment portion  58  abuts against the front wall  65 C, thereby restricted from moving in the −X-direction. 
     As shown in  FIG. 3 , the rotation shaft  61  is provided at a −Y-direction end portion of the frame portion  62 . The rotation shaft  61  is formed in a columnar shape and extends in the Z-direction. The rotation shaft  61  is rotatably provided at part of the main body frame  14 . The rotation shaft  61  has the rotation axis C 1  passing through the center of the shaft. This enables the inner door unit  60  to be switched between the open state and the closed state described above by rotating about the rotation axis C 1 . 
     The support bracket  68  is attached to a +Y-direction end portion of the frame portion  62  using a screw (not shown). 
     As shown in  FIG. 7 , the support bracket  68  is configured including a vertical plate portion  69 , a lateral plate portion  71 , a support plate portion  72 , the support shaft portion  74 , the first restriction plate portion  78 , a second restriction plate portion  79 , and a hook portion  82  ( FIG. 6 ). 
     The vertical plate portion  69  is attached to a +Y-direction end portion of a −Z-direction part of the frame portion  62 . The lateral plate portion  71  extends in the +Y-direction from a +Z-direction end portion of the vertical plate portion  69 . 
     The support plate portion  72  extends upright in the +Z-direction from a +Y-direction end portion of the lateral plate portion  71 . The support plate portion  72  is provided with a plurality of shaft portions  73  that extend in the +Y-direction and are arranged side by side in the Z-direction. The plurality of shaft portions  73  support the gears (not shown) of the gear section  84  to be described later in such a manner that the gears are rotatable. The support shaft portion  74  is provided at a +Z-direction portion of the support plate portion  72 . 
     The support shaft portion  74  is formed in a tubular shape opening in the Y-direction. Part of a shaft  76  ( FIG. 8 ) is fit into the support shaft portion  74 . Thus, the support bracket  68  supports the shaft  76 . 
     The first restriction plate portion  78  extends in the −Y-direction from a −X-direction end portion of a center portion and a lower portion, in the Z-direction, of the support plate portion  72 . The contact portion  56 A described earlier comes into contact with part of the first restriction plate portion  78 . Then, when the contact portion  56 A is in contact with the first restriction plate portion  78 , the first restriction plate portion  78  restricts the contact portion  56 A from moving in the −X-direction beyond the first restriction plate portion  78 . 
     The second restriction plate portion  79  extends in the −Y-direction from a −X-direction end portion of an upper portion, in the Z-direction, of the support plate portion  72 . A front wall portion  111  and a rear wall portion  114  ( FIG. 9 ) to be described later come into contact with part of the second restriction plate portion  79 . When the front wall portion  111  is in contact with the second restriction plate portion  79 , the second restriction plate portion  79  restricts the front wall portion  111  from moving in the −X-direction beyond the second restriction plate portion  79 . Also, when the rear wall portion  114  is in contact with the second restriction plate portion  79 , the second restriction plate portion  79  restricts the rear wall portion  114  from moving in the +X-direction beyond the second restriction plate portion  79 . 
     The hook portion  82  ( FIG. 8 ) is a part projecting in the +X-direction from a −Y-direction end portion of the first restriction plate portion  78 . The hook portion  82  is formed in an inverted letter-U shape opening in the −Z-direction. Note that the hook portion  82  is located on the +Z-direction side relative to the guide portion  65 . 
     The gear section  84  has the transmission gear  44  mentioned earlier, a plurality of transmission gears  84 A ( FIG. 11 ), a drive gear  84 B, and a plurality of gears (not shown). The transmission gear  44  is disposed at a −Z-direction end portion of the gear section  84 . The drive gear  84 B is disposed at a +Z-direction end portion of the gear section  84 . The plurality of gears transmit a drive force from the transmission gear  44  to the drive gear  84 B via the plurality of transmission gears  84 A. 
     The cover member  86  has a first side wall  87 , a second side wall  88 , and a third side wall  89  ( FIG. 5 ). 
     The first side wall  87  is located on the +X-direction side relative to the gear section  84 . The second side wall  88  is located on the −X-direction side relative to the gear section  84 . The third side wall  89  is disposed at a +Y-direction side relative to the gear section  84 , and couples the first side wall  87  and the second side wall  88  to each other in the X-direction. The cover member  86  thus covers the gear section  84  from three sides. The counter-abutment portion  92  is formed at a part of the first side wall  87  which is on the +Y-direction side and the +Z-direction side of the center of the first side wall  87  when seen in the +X-direction. 
     The counter-abutment portion  92  is a part protruding from the first side wall  87  in the +X-direction. When the inner door unit  60  is in the closed state, the counter-abutment portion  92  is a part against which the second abutment portion  54  abuts in the −X-direction. 
     As shown in  FIG. 4 , the pinch rollers  94  are an example of the rotatable roller and each have a columnar shaft portion  94 A extending in the Y-direction, a wider diameter portion  94 B increased in diameter radially from the shaft portion  94 A, and a plurality of teeth  94 C formed at the outer circumferential surface of the wider diameter portion  94 B. In a state where the inner door unit  60  is receiving a pressing force from the outer door unit  30 , the pinch rollers  94 , together with the rubber rollers  36 , transport a sheet P by pinching the sheet P and rotating. 
     The press springs  96  are each attached to the first frame  63  at one end and is in contact with the shaft portion  94 A at the other end, thereby being elastically deformable in the X-direction. Then, the press spring  96  applies an elastic force to the shaft portion  94 A, thereby pressing the shaft portion  94 A toward the rubber rollers  36 . In other words, the press spring  96  is an example of the press member and presses the pinch roller  94  against the outer door unit  30 . Note that the plurality of pinch rollers  94  and the plurality of press springs  96  are disposed at the inner door unit  60 . 
     As shown in  FIG. 6 , the lock mechanism section  100  brings the inner door unit  60  into the closed state by locking the inner door unit  60  against the apparatus main body  12  and brings the inner door unit  60  into the open state by unlocking the inner door unit  60  from the apparatus main body  12 . Specifically, the lock mechanism section  100  includes the counter-engagement shaft  55  ( FIG. 9 ) described earlier, a lock lever  102 , and a tension spring  122 . 
     As shown in  FIG. 9 , the lock lever  102  is an example of the engagement portion and has an engagement surface  108  to be described later. The lock lever  102  has the shaft  76  and a lever main body  104  that rotates about the axial center of the shaft  76 . The shaft  76  is, as described earlier, supported by the support bracket  68  ( FIG. 7 ). Thus, the lock lever  102  is provided at the inner door unit  60  ( FIG. 1 ). Note that the positions of the portions of the lock lever  102  are described regarding their positions when the inner door unit  60  is in the closed state. 
     The shaft  76  is formed in a columnar shape and extends in the Y-direction. The shaft  76  has a rotation central axis C 2  passing through the center of the shaft and extending in the Y-direction. In other words, the lock lever  102  has the central axis C 2  of rotation relative to the inner door unit  60 . When the inner door unit  60  is in the closed state, the rotation central axis C 2  is orthogonal to the rotation axis C 1  ( FIG. 3 ) when seen in the +X-direction from the −X-direction side. 
     Note that when seen in the −Y-direction from the +Y-direction side, the direction in which the inner door unit  60  is moved from an open position for the open state to a closed position for the closed state is the +X-direction. 
     The lever main body  104 , as seen in +Y-direction, includes an insertion portion  106 , a bottom wall  107 , the engagement surface  108 , an anterior surface  112 , a connection surface  109 , the front wall portion  111 , the rear wall portion  114 , a partitioning portion  115 , a grip portion  116 , and a hook portion  118 . In the present embodiment, engagement is a concept including contact. 
     The insertion portion  106  is a tubular part that opens in the Y-direction. The shaft  76  is inserted into the insertion portion  106 . The insertion portion  106  is rotatable in the circumferential direction of the shaft  76 . 
     The bottom wall  107  extends in the +X-direction from the outer circumferential surface of the insertion portion  106 . The bottom wall  107  has a bottom portion  107 A along the X-Y plane. 
     The engagement surface  108  is, by way of example, a planar surface. The engagement surface  108  can change its position between a first posture and a second posture to be described later, when the lock lever  102  is rotated in the X-direction intersecting with the Y-direction, the X-direction being an example of the second direction. The engagement surface  108  is engageable with the counter-engagement shaft  55 . Further, in a closing operation of the inner door unit  60 , the engagement surface  108  changes its position from the first posture to the second posture while shifting a position of contact G with the counter-engagement shaft  55 . Also, in the closing operation and the closed state of the inner door unit  60 , the engagement surface  108  exerts, to the counter-engagement shaft  55 , a pull-in force for moving the inner door unit  60  to the closed position. 
     As shown in  FIG. 12B , the first posture of the engagement surface  108  means the posture assumed by the engagement surface  108  when the connection surface  109  to be described later reaches the +Z-direction vertex of the counter-engagement shaft  55 . In this posture, the engagement surface  108  is slanted with its +X-direction end portion being located on the −Z-direction side relative to its −X-direction end portion. In other words, the engagement surface  108  is, when seen in the +Y-direction, a slanted surface extending in an intersecting direction intersecting with the Z-direction. This intersecting direction is referred to as an A-direction. An angle θ 1  formed between the Z-direction and the A-direction is larger than 0 [°] and smaller than 45 [°]. The angle θ 1  is, by way of example, 20 [°]. 
     As shown in  FIG. 9 , the second posture of the engagement surface  108  means the posture assumed by the engagement surface  108  when the inner door unit  60  is in the closed state and when the engagement surface  108  engages with the counter-engagement shaft  55 . In this posture, the engagement surface  108  is slanted with its +X-direction end portion being located on the −Z-direction side relative to its −X-direction end portion. An acute angle formed between the engagement surface  108  in this posture and an imaginary line K extending in the Z-direction is referred to an angle θ 2 . The angle θ 2  is smaller than the angle θ 1  ( FIG. 12B ). 
     When seen in the Y-direction which is the axial direction of the rotation central axis C 2 , the engagement surface  108  in the second posture extends to both sides of the position of contact G with the counter-engagement shaft  55  in the slanting direction included in the in-plane direction of the engagement surface  108 . 
     In a transition from the first posture to the second posture, the engagement surface  108  comes into contact with an outer circumferential surface  55 A of the counter-engagement shaft  55 . The posture assumed by the engagement surface  108  when the engagement surface  108  starts contacting the outer circumferential surface  55 A is referred to as a third posture. 
     The engagement surface  108  in the third posture exerts, to the counter-engagement shaft  55 , a pull-in force for moving the inner door unit  60  from the open state to the closed state. 
     As shown in  FIG. 8 , when the inner door unit  60  is in the closed state, the position of contact G between the engagement surface  108  and the counter-engagement shaft  55  is located lower than the rotation central axis C 2  in the Z-direction. 
     When the inner door unit  60  is in the closed state, the position of contact G is located higher than a central axis C 3  of the counter-engagement shaft  55  in the Z-direction. 
     As shown in  FIG. 9 , the anterior surface  112  is formed at a +X-direction and −Z-direction end portion of the lever main body  104 . The anterior surface  112  is, when seen in the +Y-direction, slanted with its +X-direction end portion being located on the +Z-direction side relative to its −X-direction end portion. The anterior surface  112  is, by way of example, a planar surface. 
     When the state of the inner door unit  60  switches from the open state to the closed state, the anterior surface  112  comes into contact with the counter-engagement shaft  55  before the engagement surface  108  does. 
     As shown in  FIG. 12A , when the anterior surface  112  comes into contact with the counter-engagement shaft  55 , the lock lever  102  receives, from the counter-engagement shaft  55 , a reactive force in a rotational direction in which the engagement surface  108  is moved from the second posture to the first posture. 
     As shown in  FIG. 9 , the connection surface  109  is, in the closed state described above, a planar surface extending in the +X-direction from a +X-direction end portion of the engagement surface  108 , and is coupled to a −X-direction end portion of the anterior surface  112 . The length of the connection surface  109  in the X-direction is, by way of example, shorter than a length corresponding to the diameter of the counter-engagement shaft  55 . 
     In a transition from a state where the counter-engagement shaft  55  is in contact with the anterior surface  112  to a state where the counter-engagement shaft  55  is in contact with the engagement surface  108 , or vice versa, a moderate clicking sensation can be produced during the manipulation of the lock lever  102  due to the formation of the connection surface  109 . 
     The front wall portion  111  extends upright in the +Z-direction from a −X-direction end portion of the bottom wall  107 . 
     The rear wall portion  114  extends upright in the +Z-direction from a −X-direction end portion of the insertion portion  106 . A +Z-direction end portion of the rear wall portion  114  is bent in the +X-direction. The rear wall portion  114  is located on the −X-direction side relative to the front wall portion  111 . The second restriction plate portion  79  ( FIG. 7 ) described earlier is inserted between the front wall portion  111  and the rear wall portion  114 . 
     As shown in  FIG. 11 , when the inner door unit  60  is in the closed state, the bent part of the rear wall portion  114  is in contact with the second restriction plate portion  79  in the +X-direction from the −X-direction side. The lock lever  102  is thereby restricted from rotating too far in the +X-direction. Note that the second restriction plate portion  79  is disposed such that the anterior surface  112  ( FIG. 9 ) is not located on the −Z-direction side relative to the counter-engagement shaft  55  ( FIG. 9 ). 
     When the lock lever  102  is rotated in the −X-direction, the front wall portion  111  ( FIG. 9 ) comes into contact with the second restriction plate portion  79  in the −X-direction from the +X-direction side. The lock lever  102  is thereby restricted from rotating too far in the −X-direction. 
       FIG. 11  does not show the cover member  86  ( FIG. 7 ). 
     As shown in  FIG. 10 , the partitioning portion  115  extends upright in the +Z-direction from the Y-direction center of the bottom wall  107 , partitioning the lock lever  102  into a part on the +Y-direction side and a part on the −Y-direction side of the center of the lock lever  102  in the Y-direction. The part on the +Y-direction side includes the engagement surface  108  ( FIG. 9 ), the connection surface  109  ( FIG. 9 ), and the anterior surface  112 . The part on the −Y-direction side includes the grip portion  116  and the hook portion  118 . 
     As shown in  FIG. 11 , the grip portion  116  has a vertical wall portion  116 A extending upright in the +Z-direction from the outer circumferential surface of the insertion portion  106 , a slanted portion  116 B extending obliquely from a +Z-direction end portion of the vertical wall portion  116 A toward a +X-direction and +Z-direction position, and a projecting portion  116 C projecting from a +Z-direction part of the slanted portion  116 B to both sides in the Y-direction. 
     As shown in  FIG. 10 , the hook portion  118  is formed at the bottom wall  107 , on the +X-direction side relative to the grip portion  116 . The hook portion  118  is a part cut out in a letter-U shape opening in the +Z-direction when seen in the Y-direction. The upper end of the tension spring  122  to be described later is hooked to the hook portion  118 . When seen in the Y-direction, a portion of the hook portion  118  to be in contact with the tension spring  122  is disposed next to the engagement surface  108  ( FIG. 9 ) in the Z-direction. 
     The tension spring  122  is an example of the application member and applies a force to the lock lever  102  so that the engagement surface  108  can change its position from the first posture to the second posture described above. Specifically, the lower end of the tension spring  122  is hooked to the hook portion  82 , and the upper end of the tension spring  122  is hooked to the hook portion  118 . The lock lever  102  thereby receives a force in a direction such that the engagement surface  108  is pressed against the outer circumferential surface  55 A of the counter-engagement shaft  55 . 
     Next, the operation of the printer  10  is described. 
     Note that for the configurations of the components of the printer  10 ,  FIGS. 1 to 12B  are to be referred to, and the numbers of the drawings are not described below. 
     For an operation to open the inner door unit  60  in the closed state, an operator grips and tilts the grip portion  116  in the −X-direction against the pulling force exerted by the tension spring  122 , thereby rotating the lock lever  102  in the −X-direction. In this event, the engagement surface  108  moves while shifting the position of contact G with the outer circumferential surface  55 A in the +Z-direction and then moves away from the outer circumferential surface  55 A. Then, the connection surface  109  climbs over the counter-engagement shaft  55  in the −X-direction, so that the lock lever  102  and the counter-engagement shaft  55  are disengaged from each other, enabling the opening operation of the inner door unit  60 . 
     For an operation to close the inner door unit  60  in the open state, an operator pushes a +Y-direction end portion of the inner door unit  60  in the +X-direction, thereby rotating the inner door unit  60  toward the closed position. Note that for the closing operation, the lock lever  102  is not operated by the operator. 
     When the inner door unit  60  approaches the closed position, the anterior surface  112  comes into contact with the outer circumferential surface  55 A in the +X-direction. In this event, the anterior surface  112  receives a reactive force from the counter-engagement shaft  55 , so that the lock lever  102  rotates in the −X-direction. Then, the connection surface  109  climbs over the counter-engagement shaft  55  in the +X-direction, and the engagement surface  108  comes into contact with the outer circumferential surface  55 A. In this event, the engagement surface  108  moves to the position for the closed state while shifting the position of contact G by generating a pull-in force. As a result, the lock lever  102  engages with the counter-engagement shaft  55 , bringing the inner door unit  60  into the closed state. 
     In this way, in the closing operation and in the closed state, the engagement surface  108  applies, to the counter-engagement shaft  55 , a pull-in force for moving the inner door unit  60  to the closed state. 
     In the printer  10 , the pull-in force remains exerted in the closed state, which makes it unlikely for the inner door unit  60  to be opened by mistake. 
     As thus described, according to the printer  10 , when the inner door unit  60  is operated from the open position to the closed position, the engagement surface  108  comes into contact with the counter-engagement shaft  55 . As the inner door unit  60  approaches the closed position, the engagement surface  108  changes its posture from the first posture to the second posture. The engagement surface  108  changes its posture from the first posture to the second posture while shifting the position of contact G with the counter-engagement shaft  55 . In other words, the engagement surface  108  changes its posture with the engagement surface  108  and the counter-engagement shaft  55  staying in contact with each other. Thus, there is no need for the lock lever  102  to overstroke in the +X-direction. 
     The elimination of the need for the overstroke of the lock lever  102  can reduce the interference between the main body gear  42  and the transmission gear  44 . 
     According to the printer  10 , the rotation central axis C 2  of the lock lever  102  is immobile. Thus, compared to a configuration in which the whole lock lever  102  slides, the mechanism for moving the lock lever  102  can be simplified. 
     According to the printer  10 , because the anterior surface  112  comes into contact with the counter-engagement shaft  55 , the engagement surface  108  and the counter-engagement shaft  55  transition into a contacting state after the lock lever  102  is rotated in a direction in which the engagement surface  108  is moved from the second posture to the first posture. In other words, the lock lever  102  can easily rotate before the engagement surface  108  and the counter-engagement shaft  55  come into contact with each other, which makes it easy for the engagement surface  108  and the counter-engagement shaft  55  to transition into a contacting state. 
     According to the printer  10 , when the inner door unit  60  is moved from the open state to the closed state, the area of contact between the engagement surface  108  and the counter-engagement shaft  55  gradually increases, and also the friction force acting on the engagement surface  108  gradually increases in comparison to the configuration in which the lock lever  102  slides. Thus, a feel of jerkiness felt when the inner door unit  60  is brought into the closed state can be reduced. 
     According to the printer  10 , the rotation central axis C 2 , which is the center of rotation of the lock lever  102 , is located higher than the position of contact G between the engagement surface  108  and the counter-engagement shaft  55  in the Z-direction. This makes it easier for the engagement surface  108  to move away from the counter-engagement shaft  55  at the time of unlocking and thus makes unlocking easier. 
     According to the printer  10 , the first abutment portion  51 , the second abutment portion  54 , and the third abutment portion  58  restrict the movement of the inner door unit  60  in the closed state. Since the counter-engagement shaft  55  is at a position overlapping with the first abutment portion  51  in the Z-direction, the position of contact G between the engagement surface  108  and the counter-engagement shaft  55  and the position where the first abutment portion  51  restricts the inner door unit  60  are closely disposed. This helps prevent overstroke operation of the inner door unit  60  in the +X-direction when the engagement surface  108  and the counter-engagement shaft  55  come into contact with each other. 
     According to the printer  10 , even if the position of contact G between the engagement surface  108  and the counter-engagement shaft  55  is displaced, the engagement surface  108  and the counter-engagement shaft  55  can be brought into contact with each other because the engagement surface  108  extends to both sides of the position of contact G. 
     According to the printer  10 , regarding the force acting on the position of contact G between the engagement surface  108  and the counter-engagement shaft  55 , a component force in a horizontal direction orthogonal to the Z-direction is large compared to a configuration in which the angle θ 1  formed between the Z-direction and the A-direction exceeds 45°. Thus, it is easier to obtain a pull-in force exerted when the lock lever  102  comes into contact with the counter-engagement shaft  55 . 
     According to the printer  10 , the outer door unit  30  presses the inner door unit  60  in the closed state against the apparatus main body  12 , thereby restricting the inner door unit  60  from moving to the open position. Thus, the inner door unit  60  can stay in the closed state. 
     According to the printer  10 , the pinch rollers  94  are pressed against the rubber rollers  36  by receiving a pressing force from the press springs  96  while in contact with the rubber rollers  36 . Even if the outer door unit  30  is operated to overstroke relative to the inner door unit  60 , the press springs  96  elastically deform and thereby can absorb the pressing force that the rubber rollers  36  exert to the pinch rollers  94 . Thus, deformation of the pinch rollers  94  can be reduced. 
     According to the printer  10 , even if a sheet P is jammed during transport, opening the inner door unit  60  or the outer door unit  30  makes it possible to remove the recorded sheet P and therefore unlikely for the recorded sheet P to remain in the discharge path T 2  or in the feed-in path T 4  and the switch-back path T 5 . 
     According to the printer  10 , the line head  28  performs recording on a sheet P transported thereto. Even if the recorded sheet P is jammed during transport, opening the inner door unit  60  or the outer door unit  30  makes it possible to remove the recorded sheet P and therefore unlikely for the recorded sheet P to remain in the discharge path T 2  or in the feed-in path T 4  and the switch-back path T 5 . 
     Although the printer  10  according to the embodiment of the present disclosure basically has the configuration described above, it goes without saying that the configuration may be partly modified or omitted without departing from the gist of the disclosure of the present application. 
     In the printer  10 , the lock lever  102  may be without the rotation central axis C 2  and configured to slide linearly. 
     The anterior surface  112  is not limited to a planar surface and may be a curved surface. It is also possible not to form a slanted surface like the anterior surface  112 . 
     The engagement surface  108  is not limited to a planar surface and may be a curved surface. 
     The rotation central axis C 2  may intersect with the rotation axis C 1  instead of being orthogonal thereto. 
     The position of contact G between the engagement surface  108  and the counter-engagement shaft  55  in the closed state may be located at the same position as the rotation central axis C 2  or higher than the rotation central axis C 2  in the Z-direction. 
     The lock lever  102  may be provided at the apparatus main body  12 , and the counter-engagement shaft  55  may be provided at the inner door unit  60 . 
     In the printer  10 , the engagement surface  108  in the second posture may extend to one side of the position of contact G with the counter-engagement shaft  55  when seen in the axial direction of the rotation central axis C 2 . 
     The angle θ 1  formed between the Z-direction and the A-direction may be 45° or greater. 
     The outer door unit  30  may be configured not to be pressed against the inner door unit  60 . 
     The pinch rollers  94  and the press springs  96  may be provided at the outer door unit  30 , and the rubber rollers  36  may be provided at the inner door unit  60 . 
     No transport path for a sheet P has to be formed between the inner door unit  60  and the outer door unit  30 . 
     The printer  10  may be without the line head  28  so as to be configured simply as a medium transport apparatus that transports a sheet P. 
     The plurality of rotating bodies may be such that one of them is provided at the apparatus main body  12 , and one of them is of them are provided at the inner door unit  60 . 
     The inner door unit  60  is not limited to being configured such that the rotation axis C 1  extends vertically, and may be configured such that the rotation axis C 1  extends horizontally.