Patent Publication Number: US-9834016-B2

Title: Medium holder and liquid ejecting apparatus

Description:
BACKGROUND 
     1. Technical Field 
     The present invention relates to a liquid ejecting apparatus, and technology for holding and handling a medium thereof. 
     2. Related Art 
     In a liquid ejecting apparatus such as an ink jet printer, medium may be pulled out from a medium roll that is the wound medium, and the medium then used. When utilizing a medium roll, as in JP-A-2009-23171, for example, a support member (adapter) is mounted onto an end portion of the medium roll in an axial direction. The medium roll is attached to the liquid ejecting apparatus through the support member. In such a liquid ejecting apparatus, medium is pulled out from the medium roll and transported, and a liquid such as ink is ejected from a liquid ejecting head, so that printing is performed on the medium. 
     SUMMARY 
     In recent years, the medium roll has been increasing in size and the medium roll itself has become increasingly heavy. Accordingly, the heavier the medium roll becomes, the greater the burden placed on a worker during handling or replacement operations, or the like, of the medium roll. For example, hitherto, such heavy medium rolls have been directly lifted and handled by a worker, or have been handled by moving on a cart. In a handling operation of a medium roll, greater effort is required as the medium roll becomes heavier, and the burden on the worker significantly increases as well. An advantage of some aspects of the invention is that worker effort for handling a medium roll is reduced. 
     A medium holder according to an aspect of the invention includes a medium roll being a wound medium, and a medium holder unit that is mounted onto an end portion of the medium roll in an axial direction. The medium holder unit includes a movement mechanism having a rotating body that moves the medium roll. According to the above configuration, the medium holder unit includes the movement mechanism having the rotating body that moves the medium roll, thus enabling the medium holder to stand by itself on, for example, a floor and be moved in this state across the floor, using the rotating body of the movement mechanism. A worker can therefore easily move the medium holder without using a cart, enabling worker effort for handling the medium roll to be greatly reduced. 
     It is preferable that the movement mechanism includes the rotating body provided at a position at which the rotating body moves the medium roll in at least one of a direction intersecting the axial direction of the medium roll and a direction along the axial direction. According to the above configuration, the medium roll can be moved in at least one of the direction intersecting the axial direction of the medium roll and the direction along the axial direction. 
     It is preferable that the rotating body is provided to at least one of an end face and a side face of the medium holder unit. According to the above configuration, a rotating body provided to the end face of the medium holder unit enables the medium roll to be moved in the direction intersecting the axial direction of the medium roll, and a rotating body provided to the side face of the medium holder unit enables the medium roll to be moved in the direction along the axial direction. 
     It is preferable that the movement mechanism is provided with a lock mechanism that locks the rotating body. According to the above configuration, the rotating body is locked by the lock mechanism, enabling movement of the medium holder to be restricted. 
     It is preferable that the lock mechanism locks the rotating body when the medium holder receives an impact force of a specific threshold value or greater. According to the above configuration, the rotating body is locked when the medium holder receives an impact force of the specific threshold value or greater, enabling movement to be restricted when the medium holder has fallen over, for example, and so safety can be increased. 
     It is preferable that the medium holder further includes a cover that covers the medium roll, and that the cover is housed in the medium holder unit. According to the above configuration, the cover can be taken out from the medium holder unit so as to cover the medium roll during handling or storage. The cover can also be housed in the medium holder unit when mounting the medium holder in a liquid ejecting apparatus. 
     It is preferable that the medium holder further includes a coupling member that couples together medium holder units mounted onto each of plural of medium rolls. According to the above configuration, plural medium holders can be moved at once while in a coupled state. 
     It is preferable that the rotating body is configured from a shock absorbing material. According to the above configuration, the rotating body is configured from a shock absorbing material, enabling an impact when the medium holder falls over, for example, to be softened. 
     It is preferable that the rotating body is provided through a shock absorbing mechanism. According to the above configuration, the rotating body is provided through a shock absorbing mechanism, enabling an impact when the medium holder falls over, for example, to be softened. 
     A liquid ejecting apparatus according to another aspect of the invention includes a medium mounting portion onto which the medium holder according to the above aspect is mounted, a transport mechanism that pulls the medium out from the medium holder and transports the medium, and a liquid ejecting head that ejects a liquid onto the medium transported by the transport mechanism. The liquid ejecting apparatus is, for example, a printer that ejects ink onto a medium such as printing paper; however, the liquid ejecting apparatus according to an aspect of the invention is not limited to printing applications. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a configuration diagram of a liquid ejecting apparatus according to a first embodiment. 
         FIG. 2  is an exploded perspective view of a medium holder. 
         FIG. 3  is a diagram of the medium holder of  FIG. 2 , as viewed along an axial direction. 
         FIG. 4  is a diagram explaining operation when a medium holder is handled in a vertical orientation. 
         FIG. 5  is a diagram explaining operation when a medium holder is handled in a horizontal orientation. 
         FIG. 6  is an external perspective view illustrating configuration of a medium holder according to a first modified example of the first embodiment. 
         FIG. 7  is an external perspective view illustrating configuration of a medium holder according to a second modified example of the first embodiment. 
         FIG. 8  is an external perspective view illustrating configuration of a medium holder according to a third modified example of the first embodiment. 
         FIG. 9  is an external perspective view illustrating configuration of a medium holder according to a fourth modified example of the first embodiment. 
         FIG. 10  is a diagram of the medium holder of  FIG. 9 , as viewed along an axial direction. 
         FIG. 11  is an external perspective view illustrating configuration of a medium holder according to a second embodiment. 
         FIG. 12  is an explanatory operation diagram illustrating a locked state of the medium holder of  FIG. 11 . 
         FIG. 13  is an explanatory operation diagram illustrating a lock-released state of the medium holder of  FIG. 11 . 
         FIG. 14  is a diagram illustrating a locked state of a lock release button. 
         FIG. 15  is a diagram illustrating a lock-released state of a lock release button. 
         FIG. 16  is a diagram illustrating a process of forcing a lock release button to transition from a lock-released state to a locked state. 
         FIG. 17  is an external perspective view illustrating configuration of a medium holder according to a third embodiment. 
         FIG. 18  is an explanatory operation diagram illustrating a process of storing the cover of  FIG. 17 . 
         FIG. 19  is an explanatory operation diagram illustrating a state after storing the cover of  FIG. 17 . 
         FIG. 20  is an external perspective view illustrating configuration of a medium holder according to a fourth embodiment. 
         FIG. 21  is an external perspective view illustrating configuration of a medium holder according to a fifth embodiment. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     First Embodiment 
       FIG. 1  is a diagram illustrating partial configuration of a liquid ejecting apparatus  10  according to a first embodiment of the invention. The liquid ejecting apparatus  10  of the first embodiment is an ink jet printing apparatus in which medium  22  is pulled out from a medium roll  20  that is the medium  22  having been wound into a roll shape, and ink, this being an example of a liquid, is ejected onto the medium. The liquid ejecting apparatus  10  illustrated in  FIG. 1  is equipped with a controller  12 , a transport mechanism  14 , a liquid ejecting unit  15 , and a carriage  16 . A liquid container (cartridge)  18  that stores ink is mounted on the liquid ejecting apparatus  10 . Ink is supplied from the liquid container  18  to the liquid ejecting unit  15 . 
     The controller  12  performs overall control of respective elements of the liquid ejecting apparatus  10 . Under control of the controller  12 , the transport mechanism  14  pulls the medium  22  out from the medium roll  20  and transports the medium  22  along a Y direction. The liquid ejecting unit  15  is equipped with plural liquid ejecting heads  19 . Under the control of the controller  12 , each of the liquid ejecting heads  19  ejects ink from plural respective nozzles N onto the medium  22 . Each of the liquid ejecting heads  19  includes plural groups of pressure chambers and piezoelectric elements (not illustrated in the drawings) that correspond to different nozzles N. By supplying drive signals that cause the piezoelectric elements to vibrate such that pressure inside the pressure chambers fluctuates, ink loaded inside the pressure chambers is ejected from the respective nozzles N. 
     The carriage  16  is installed with the liquid ejecting unit  15 . The controller  12  moves the carriage  16  to and fro along an X direction intersecting the Y direction. In parallel with the transportation of the medium  22  by the transport mechanism  14  and the repeated to and fro movement of the carriage  16 , the liquid ejecting heads  19  eject ink onto the medium  22  such that a desired image is formed on a surface of the medium  22 . Note that, for example, it is possible for the carriage  16  to be equipped with plural liquid ejecting units  15  that eject different types of ink. A cutter, not illustrated in the drawings, is provided to the liquid ejecting apparatus  10 . After printing, the medium  22  is cut by the cutter and discharged to a discharge tray, not illustrated in the drawings. 
     The medium roll  20  is mounted on a medium mounting portion  11  provided in the liquid ejecting apparatus  10 . Medium holder units  40  are mounted onto the medium roll  20  of the present embodiment at each of two respective end portions  21  along a G-G axial line direction, the G-G axial line direction being the axial line of the medium roll  20 . The medium holder units  40  and the medium roll  20  configure a medium holder  30 . A support shaft (spindle)  111  is provided to each medium mounting portion  11 . The medium roll  20  is rotatably mounted through the medium holder units  40  onto the support shafts  111 . 
     In recent years, the medium roll  20  has been increasing in size and the medium roll  20  itself has become increasingly heavy. Accordingly, the heavier the medium roll  20  becomes, the greater the burden placed on a worker during handling or replacement operations, or the like, of the medium roll  20 . In the present embodiment, movement mechanisms  42  are provided to the medium holder units  40  of the medium holder  30  such that the medium roll  20  can be handled without a cart. Namely, the medium holder  30  can be handled while the medium holder units  40  are mounted to the medium roll  20 . 
       FIG. 2  is an exploded perspective view illustrating configuration of the medium holder  30  according to the present embodiment.  FIG. 3  is a diagram of the medium holder  30 , as viewed along the G-G axial line direction. As illustrated in  FIG. 2  and  FIG. 3 , the medium holder  30  is configured by the medium roll  20  and two medium holder units  40 . The two medium holder units  40  are mounted onto the two respective end portions  21  of the medium roll  20 . The medium roll  20  is formed by winding the medium  22  into a roll shape about a hollow shaft (winding core)  24 . 
     As the two medium holder units  40  illustrated in  FIG. 2  have similar configuration to each other, in the following, explanation is given using the medium holder unit  40  on the minus side in the X direction as an example. The medium holder unit (adapter)  40  includes a shaft portion  43  that is inserted into the hollow shaft  24  of the medium roll  20  and a flange portion  44 . The flange portion  44  is in the shape of a bottomed cylinder, and includes an end face (first end face)  442  on the side of the medium roll  20 , an end face (second end face)  444  on the opposite side to the end face  442 , and a side face (circumferential face)  446 . The shaft portion  43  projects out from the end face  442  of the flange portion  44 . The shaft portion  43  is fitted into the hollow shaft  24  of the medium roll  20  to mount the flange portion  44  onto the end portion  21  of the medium roll  20 . The outer diameter of the flange portion  44  is larger than the outer diameter of the medium roll  20 . As illustrated in  FIG. 3 , the end face  444  of the flange portion  44  is provided with a shaft hole  445  into which the support shaft  111  of the respective medium mounting portion  11  described above is inserted. 
     As illustrated in  FIG. 2  and  FIG. 3 , a movement mechanism  42  is provided to the medium holder unit  40  of the present embodiment. The movement mechanism  42  of the present embodiment includes plural rotating bodies  422  provided at positions at which the rotating bodies  422  move the medium roll  20  in a direction intersecting the G-G axial line direction of the medium roll  20  (a movement direction in a vertical orientation), and plural rotating bodies  422  provided at positions at which the rotating bodies  422  move the medium roll  20  in a direction along the G-G axial line direction (a movement direction in a horizontal orientation). 
     In the present embodiment, four of the rotating bodies  422  are provided to the end face  444  of the flange portion  44  such that they project out from the end face  444 . The rotating bodies  422  of the end face  444  are disposed surrounding the shaft hole  445  at evenly spaced intervals. Each of the rotating bodies  422  is rotatably supported by a support body  423  provided to the end face  444 . Six of the rotating bodies  422  are provided to the side face  446  of the flange portion  44  such that they project out from the side face  446 . The rotating bodies  422  of the side face  446  are disposed at evenly spaced around the circumferential direction of the side face  446 . However, the number and arrangement of the rotating bodies  422  are not limited thereto. 
     The rotating bodies  422  of the present embodiment are spherically shaped rollers. Each of the rotating bodies  422  is rotatably supported by a respective support body  423  provided to the side face  446 . However, the rotating bodies  422  are not limited to spherically shaped rollers, and may be circular column shaped rollers. The rotating bodies  422  are not limited to rollers, and may be casters or the like. Each of the rotating bodies  422  is configured from a shock absorbing material such as a rubber or an elastomer. An impact when the medium holder  30  falls over, for example, can thereby be softened, and so the medium roll  20  itself is able to be protected, and damage imparted to an object or person struck by the medium holder  30  in a fall can be reduced. Note that a shock absorbing mechanism (a damping mechanism) such as rubber or a spring may be provided to the support bodies  423  of the rotating bodies  422 . For example, impact when the medium holder  30  falls can also be softened by mounting the rotating bodies  422  to the respective support bodies  423  through a spring. A boundary portion between the end face  444  and the side face  446  of each flange portion  44  may also be provided with a corner protector configured from a shock absorbing material such as a rubber or an elastomer. 
       FIG. 4  and  FIG. 5  are explanatory diagrams of operations during handling the medium holder  30  according to the present embodiment.  FIG. 4  is a case in which the medium holder  30  is handled in a vertically oriented state, and  FIG. 5  is a case in which the medium holder  30  is handled in a horizontally oriented state. As illustrated in  FIG. 4 , when the medium holder  30  according to the present embodiment is vertically oriented, with its G-G axial line in a direction perpendicular to a floor D, the rotating bodies  422  of the end face  444  of the flange portion  44  abut the floor D. The medium holder  30  can therefore stand by itself in a vertical orientation. In this vertically oriented state, the medium holder  30  can be easily moved across the floor D. When the medium holder  30  according to the present embodiment is horizontally oriented, with its G-G axial line in a direction along the floor D, the rotating bodies  422  of the side face  446  of the flange portions  44  abut the floor D. The medium holder  30  can therefore stand by itself in a horizontal orientation, and in this horizontally orientated state, the medium holder  30  can be easily moved across the floor D. 
     Thus, according to the present embodiment, the medium holder  30  can stand by itself whether vertically oriented or horizontally oriented, thus facilitating storage and the like of the medium holder  30 . Moreover, whether vertically oriented or horizontally oriented, the medium holder  30  can be moved across a floor D in that state. A worker can therefore easily move the medium holder  30  without using a cart, enabling worker effort for handling the medium roll  20  to be greatly reduced. Moreover, since the shaft hole  445  is formed in the medium holder unit  40 , the medium holder unit  40  can be mounted on the support shaft  111  of the respective medium mounting portion  11  in a state in which the medium holder unit  40  has been mounted onto the medium roll  20 . This enables not only burden in handling operations of the medium roll  20 , but also burden in replacement operations, to be reduced. In cases in which the medium holder  30  is vertically oriented, the placement area of the medium holder  30  is able to be reduced compared to cases in which the medium holder  30  is horizontally oriented. 
     In the first embodiment, although an example has been given of a case in which the rotating bodies  422  are provided to both the end face  444  and the side face  446  of the flange portion  44 , there is no limitation thereto, and for example, configuration may be made in which the rotating bodies  422  are provided to one out of the end face  444  and the side face  446  of the flange portion  44  as in the first modified example to the fourth modified example illustrated below. Note that in the respective modified examples, elements having similar operation or functionality as those already described use the reference numerals as those employed in the explanations of  FIG. 2  to  FIG. 5 , and respective detailed explanation thereof is omitted as appropriate. 
     For example,  FIG. 6  is an external perspective view illustrating configuration of a medium holder  30  according to a first modified example of the first embodiment. The medium holder  30  of  FIG. 6  is a member in which rotating bodies  422  are only provided to the end face  444  of the flange portion  44 . According to the first modified example, the medium holder  30  can stand by itself in a vertical orientation, and the medium holder  30  can be moved in this vertically oriented state.  FIG. 7  is an external perspective view illustrating configuration of a medium holder  30  according to a second modified example of the first embodiment. The medium holder  30  of  FIG. 7  is a member in which rotating bodies  422  are only provided to the side face  446  of the flange portion  44 . According to the second modified example, the medium holder  30  can stand by itself in a horizontal orientation, and the medium holder  30  can be moved in this horizontally orientated state. 
       FIG. 8  is an external perspective view illustrating configuration of a medium holder  30  according to a third modified example of the first embodiment. The medium holder  30  of  FIG. 8  is a member in which an inclined face  448  that intersects both the end face  444  and the side face  446  is formed to the end face  444  of the flange portion  44 , and rotating bodies  422  are provided to this inclined face  448 . According to the third modified example, the medium holder  30  can be moved whether vertically oriented or horizontally oriented since the rotating bodies  422  abut the floor D whether the medium holder  30  is vertically oriented or horizontally oriented. 
       FIG. 9  and  FIG. 10  are diagrams illustrating configuration of a medium holder  30  according to a fourth modified example of the first embodiment.  FIG. 9  is an external perspective view of the medium holder  30  according to the fourth modified example.  FIG. 10  is a diagram of the medium holder  30  of  FIG. 9 , as viewed along the G-G axial line direction. The medium holder  30  illustrated in  FIG. 9  and  FIG. 10  is a member in which a plane portion  449  that is level with respect to the floor D is formed to a portion of the side face  446  of the flange portion  44 , and rotating bodies  422  are disposed at this plane portion  449 . According to the fourth modified example, since the rotating bodies  422  of the end face  444  abut the floor D when vertically oriented, and the rotating bodies  422  of the plane portion  449  abut the floor D when horizontally oriented, the medium holder  30  can be moved whether vertically oriented or horizontally oriented. 
     Second Embodiment 
     Explanation follows regarding a second embodiment of the invention. In the following embodiments, elements having similar operation or functionality to that of the first embodiment use the reference numerals employed in the explanation of the first embodiment, and respective detailed explanation thereof is omitted as appropriate.  FIG. 11  is an external perspective view of configuration illustrating a medium holder  30  according to the second embodiment. 
     In the configuration of  FIG. 11 , lock mechanisms  50  that lock the rotating bodies  422  are provided to the movement mechanisms  42  of the medium holder  30  of the first embodiment. A lock mechanism  50  is provided inside each flange. The lock mechanism  50  includes a circular plate member  52  for locking the rotating bodies  422  of the end face  444 , and a circular tube member  54  for locking the rotating bodies  422  of the side face  446 . The circular plate member  52  is provided so as to be capable of moving along the G-G axial line direction, between a position that abuts and locks the rotation of every rotating body  422  of the end face  444  and, and a position that is away from the rotating bodies  422  of the end face  444  and that releases the locking. An outer circumferential face of the circular tube member  54  is provided so as to be capable of moving along a direction intersecting the G-G axial line direction (a peripheral direction), between a position that abuts and locks the rotation of every rotating body  422  of the side face  446 , and a position that is away from the rotating bodies  422  of the side face  446  and that releases the locking. 
     The circular plate member  52  and the circular tube member  54  are driven by a lock release button  55  provided to the side face  446  of the flange portion  44 . When the lock release button  55  is not being pushed down, the circular plate member  52  and the circular tube member  54  are in a position locking the rotating bodies  422 . When the lock release button  55  is pushed down, the circular plate member  52  and the circular tube member  54  move to a position releasing the locking of the rotating bodies  422 . 
     A movable mechanism (not illustrated in the drawings) is provided to the circular plate member  52  and the circular tube member  54 . The rotating bodies  422  adopt a locked state or a lock-released state according to the operation of the movable mechanism. To be more specific, for example, a spring, not illustrated in the drawings, is provided on the inside of the circular plate member  52  and the circular tube member  54 . In the locked state, the circular plate member  52  and the circular tube member  54  are pushed out toward the outside by the biasing force of the spring so as to cause contact with the rotating bodies  422 , thereby fixing the rotating bodies  422  with friction therefrom, and achieving the locked state. A gear is provided to the inside of the lock release button  55 . The gear rotates when the lock release button  55  is pushed in. A string is wound around the gear, and the string is connected to the circular plate member  52  and the circular tube member  54 . When the lock release button  55  is pushed in, the string is wound on the gear, and the circular plate member  52  and the circular tube member  54  are respectively pulled back to the inside and separated from the rotating bodies  422 , thereby releasing the locking. 
       FIG. 12  and  FIG. 13  are diagrams explaining operation of the medium holder  30  of  FIG. 11 , and are diagrams in which one of the flange portions  44  has been enlarged.  FIG. 12  illustrates a state in which the rotating bodies  422  are locked (the locked state), and  FIG. 13  illustrates a state in which the locking of the rotating bodies  422  has been released (the lock-released state). Note that in  FIG. 12  and  FIG. 13 , the flange portion  44  is illustrated by a dotted line to make the inside easier to see. 
     As illustrated in  FIG. 12 , when the lock release button  55  is not being pushed down, the circular plate member  52  and the circular tube member  54  abut and lock the rotating bodies  422 . Movement of the medium holder  30  is thereby restrained. In contrast thereto, as illustrated in  FIG. 13 , when the lock release button  55  is pushed down, the circular plate member  52  and the circular tube member  54  move away from the rotating bodies  422  and the locking is released. Movement of the medium holder  30  thus becomes possible. 
       FIG. 14  to  FIG. 16  are diagrams for explaining the configuration and operation of the lock release button  55 .  FIG. 14  illustrates a locked state, and  FIG. 15  illustrates a lock-released state.  FIG. 16  illustrates a process forcing transition from the lock-released state to the locked state when an impact force is received in a fall or the like. 
     As illustrated in  FIG. 14 , the lock release button  55  is configured by a movable shaft  552  and a leading end portion  553 . The lock release button  55  is housed in a case  60  provided at the inside of the side face  446  such that the leading end portion  553  is capable of projecting from and retracting into a hole  447  in the side face  446 . A base end of the lock release button  55  is coupled to a movable mechanism (not illustrated in the drawings) that moves the circular plate member  52  and the circular tube member  54  described above. A spring S 1 , which provides a bias in the direction that the leading end portion  553  projects out from the hole  447 , is provided to the base end side of the lock release button  55 . 
     An anchor member  62  that anchors the lock release button  55  is provided inside the case  60 . The anchor member  62  is formed with a first step portion  622  that anchors the lock release button  55  in the locked state, and a second step portion  624  that anchors the lock release button  55  in the lock-released state. A link  554  capable of rotating about a swing portion  555  is provided to the movable shaft  552  of the lock release button  55 . A leading end of the link  554  is provided with an anchor portion  556  that anchors to the anchor member  62 . A spring S 2 , which provides a bias in the direction that the anchor portion  556  is pushed against the anchor member  62 , is provided to the swing portion  555  of the link  554 . 
     According to the lock mechanism  50  thus configured, when the lock release button  55  is in the locked state of  FIG. 14 , the anchor portion  556  of the link  554  is anchored to the first step portion  622  of the anchor member  62  in a state in which the leading end portion  553  projects out from the hole  447 . Accordingly, the locked state of the rotating bodies  422  is maintained, and movement of the medium holder  30  is restricted. In the locked state of  FIG. 14 , when the leading end portion  553  of the lock release button  55  is pushed down, the lock release button  55  transitions to the lock-released state of  FIG. 15 . Namely, the anchor portion  556  of the link  554  moves and is anchored to the second step portion  624  of the anchor member  62  accompanying the lock release button  55  being pressed down. Accordingly, the locked state of the rotating bodies  422  is released, and movement of the medium holder  30  becomes possible. 
     In the lock-released state of  FIG. 15 , when, for example, the medium holder  30  falls over and receives an impact force greater than or equal to a specific threshold value, the anchor portion  556  of the link  554  momentarily comes off from the second step portion  624  of the anchor member  62  due to the impact force, as illustrated by solid lines in  FIG. 16 . Accordingly, the anchor portion  556  of the link  554  returns to the first step portion  622  of the anchor member  62  and is anchored thereto due to the biasing force of the spring S 1  and the spring S 2 , as illustrated by the dotted lines in  FIG. 16 . Thus, the rotating bodies  422  are forced into the locked state, and movement of the medium holder  30  is restricted. The specific threshold value to force transition to the locked state can be adjusted by the biasing force of the spring S 1  and the spring S 2 . 
     Note that the configuration of the anchor member  62  is not limited to that described above. For example, configuration may be made such that in the lock-released state of  FIG. 15 , when the lock release button  55  is further pressed in by a finger, the anchor portion  556  of the link  554  momentarily comes off from the second step portion  624  of the anchor member  62 , and the lock release button  55  returns to the first step portion  622  and is anchored thereto when the finger is removed. Thus, when in the lock-released state of  FIG. 15 , pressing the lock release button  55  in with a finger and then removing the finger enables transition back to the locked state of  FIG. 14 . 
     Thus, according to the second embodiment, the normal state is the locked state. When movement of the medium holder  30  is desired, it is possible to transition to the lock-released state and achieve safety since pressing down the lock release button  55  enables transition to the lock-released state and maintenance of the lock-released state. In the lock-released state, it is also possible to force transition to the locked state when the medium holder  30  falls over and receives an impact force. Accordingly, since movement of the medium holder  30  can be forcibly restricted when the medium holder  30  has fallen over, safety can be increased. 
     Third Embodiment 
     Explanation follows regarding a third embodiment of the invention.  FIG. 17  is an external perspective view illustrating configuration of a medium holder  30  according to the third embodiment. In the configuration of  FIG. 17 , a cover  45  that covers the medium roll  20  is provided to the medium holder  30  of the first embodiment. The cover  45  is formed from plural circular tube shaped cover members  452  that cover the medium roll  20 , and the cover  45  is capable of being housed in the medium holder units  40 . The cover  45  of  FIG. 17  is formed from six cover members  452 . Each medium holder unit  40  is provided with a circular tube shaped housing portion  46 . Three of the cover members  452  are stacked and housed in each housing portion  46 . Each of the three cover members  452  housed in the medium holder unit  40  is capable of sliding against the other overlapping cover members  452 . 
       FIG. 18  and  FIG. 19  are diagrams explaining operation of the cover  45  of  FIG. 17 .  FIG. 18  is an explanatory operation diagram illustrating a process of storing the cover  45 , and  FIG. 19  is an explanatory operation diagram illustrating a state after storing the cover  45  of  FIG. 17 . As illustrated in  FIG. 18 , the cover members  452  are respectively stacked in the direction of the arrows, and the cover members  452  are housed in the respective medium holder units  40  as illustrated in  FIG. 19 . Accordingly, as the cover members  452  can be taken out from the respective medium holder units  40  so as to cover the medium roll  20  during handling or storage, dust or the like can be suppressed from adhering to the medium roll  20 . Moreover, as the cover members  452  can be housed in the respective medium holder units  40  when mounting the medium holder  30  in a liquid ejecting apparatus, the medium  22  can be pulled out from the medium roll  20  and transported. Note that the number and shape of the cover members  452  are not limited to that illustrated in the third embodiment. 
     Fourth Embodiment 
     Explanation follows regarding a fourth embodiment of the invention.  FIG. 20  is an external perspective view illustrating configuration of medium holders  30  according to the fourth embodiment.  FIG. 20  illustrates a configuration in which plural of the medium holder  30  of the first embodiment are coupled together by a coupling member  70 . The coupling member  70  couples together plural of the medium holder units  40  mounted onto respective medium rolls  20 . The coupling member  70  of  FIG. 20  includes two insertion portions  72 , and a coupling portion  74  that couples these insertion portions  72  together. Each of the insertion portions  72  is inserted into a shaft hole  445  of the medium holder unit  40  of the respective medium holder  30 . According to the thus configured coupling member  70  of  FIG. 20 , two of the medium holders  30  can be coupled together. Note that by increasing the number of insertion portions  72 , the coupling member  70  can couple three or more medium holders  30  together. According to the fourth embodiment, plural medium holders  30  can be moved at once while in a coupled state. 
     Fifth Embodiment 
     Explanation follows regarding a fifth embodiment of the invention.  FIG. 21  is an external perspective view illustrating configuration of a medium holder  30  according to the fifth embodiment. Although, examples have been given of cases in which the support shafts  111  for mounting the medium roll  20  to the medium mounting portions  11  are provided to the medium mounting portions  11  in the first embodiment to the fourth embodiment, in the fifth embodiment, an example is given of a case in which support shafts  202  for mounting the medium roll  20  to the medium mounting portions  11  are provided to the medium roll  20 . 
     A support shaft  202  is provided to both end portions  21  of the medium roll  20  of  FIG. 21 . The end face  442  of the flange portion  44  of the medium holder units  40  of  FIG. 21  is formed with an insertion hole  443  in place of the shaft portion  43  of  FIG. 2 . The support shafts  202  are inserted into the insertion holes  443 , and the respective medium holder units  40  are mounted onto both end portions  21  of the medium roll  20  of  FIG. 21 . According to such a fifth embodiment, as the medium holder units  40  may also be mounted onto a medium roll  20  provided with the support shafts  202 , the medium roll  20  is able to be easily moved. In cases in which the medium roll  20  of the fifth embodiment is to be mounted onto the medium mounting portions  11 , the support shafts  202  of the medium roll  20  are mounted onto the medium mounting portions  11  after removing the medium holder units  40 . 
     Note that the first embodiment to the fifth embodiment may be combined as appropriate within a range in which there are no mutual inconsistencies, and each of the modified examples of the first embodiment may also be applied to the second embodiment to the fifth embodiment. 
     Other Modified Examples 
     The exemplary embodiments given above may be modified in various ways. Specific modified embodiments are given below. Two or more aspects freely chosen from the following examples may be combined within a range in which there are no mutual inconsistencies. 
     (1) In each embodiment described above, an example was given of a serial head in which a carriage, onto which plural liquid ejecting heads  19  have been installed, is repeatedly moved to and fro along the X direction. However, the invention can also be applied to a line head in which plural liquid ejecting heads  19  are arranged across the entire width of the medium  22 . Moreover, the method by which the liquid ejecting heads  19  eject ink is not limited to the method employing piezoelectric elements described above (a piezo method). For example, the invention can also be applied to a method in which liquid ejecting heads employ heating elements that generate bubbles in the pressure chambers using heat such that the pressure inside the pressure chambers varies (a thermal method). 
     (2) The printing apparatus in each of the embodiments given above can be applied not only to a machine dedicated to printing, but also to various other machines such as facsimile machines and copiers. The liquid ejecting apparatus of the invention is not limited to printing applications. For example, a liquid ejecting apparatus that ejects a colorant liquid can be employed as a manufacturing apparatus to form color filters for liquid crystal display apparatuses. Moreover, a liquid ejecting apparatus that ejects an electrode material liquid can be employed as a manufacturing apparatus to form wiring and electrodes on wiring substrates. 
     The entire disclosure of Japanese Patent Application No. 2016-045570, filed Mar. 9, 2016 is expressly incorporated by reference herein.