Patent Publication Number: US-2022227137-A1

Title: Ink refill container

Description:
The present application is based on, and claims priority from JP Application Serial Number 2021-006223, filed Jan. 19, 2021 and JP Application Serial Number 2021-152990, filed Sep. 21, 2021, the disclosures of which are hereby incorporated by reference herein in their entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to an ink refill container. 
     2. Related Art 
     A known container with a cap has a valve member in the opening through which liquid contents are ejected. The valve member is formed of an elastic material and segmented by slits. JP-A-2016-50007 discloses a cap with a pusher that pushing opens the valve member segmented by the slits. 
     An environmental change such as an increase in temperature may increase the inner pressure of the container. In such a case, when the container is turned upside down to eject the contents, the sum of the inner pressure and the hydraulic head pressure of the contents may exceed the pressure resistance of the valve member segmented by the slits and the contents may spurt. The cap in JP-A-2016-50007 pushing opens the slit valve with the pusher, but this does not sufficiently release the pressure from the container. Furthermore, when the cap in JP-A-2016-50007 is closed, the pusher keeps the valve member segmented by the slits open. This may result in creep deformation of the valve member. To solve the problem, there is a desire to develop a technology that reduces an increase in pressure in the container and reduces creep deformation of the valve member. 
     SUMMARY 
     According to an aspect of the present disclosure, an ink refill container includes a bottle configured to store ink and a cap detachably attached to the bottle. The bottle includes: an ink outlet forming portion that has a tubular ink outlet and an outer peripheral portion having a first screw thread; and a valve that is in the ink outlet and has a valve member. The cap includes: a tubular trunk that has a first inner peripheral portion having a second screw thread configured to engage with the first screw thread; a top portion that faces the ink outlet with the cap being attached to the bottle; and a projection that extends along a center axis of the trunk. The projection is configured to move toward the valve and push the valve member to open the valve when the cap is rotated in a first direction in which engagement between the first screw thread and the second screw thread is cancelled. The projection is configured to relatively rotate in the first direction and move away from the valve member to close the valve when the cap is rotated in a second direction in which engagement between the first screw thread and the second screw thread is established. 
     According to another aspect of the present disclosure, an ink refill container is provided. The ink refill container includes a bottle configured to store ink and a cap detachably attached to the bottle. The bottle includes: an ink outlet forming portion that has a tubular ink outlet and an outer peripheral portion having a first screw thread; and a valve that includes a valve member formed of an elastic material and disposed in the ink outlet. The valve member is segmented by at least one slit. The cap includes: a tubular trunk that has a first inner peripheral portion having a second screw thread configured to engage with the first screw thread; a top portion that faces the ink outlet with the cap being attached to the bottle; and a projection that extends along a center axis of the trunk. The projection is configured to move toward the valve member until the projection pushes the valve member and enters the slit to open the valve member when the cap is rotated in a first direction in which engagement between the first screw thread and the second screw thread is cancelled. The projection is configured to relatively rotate in the first direction and move away from the valve member to close the valve member when the cap is rotated in a second direction in which engagement between the first screw thread and the second screw thread is established. 
     The valve of the ink refill container may further include a sealing member in the ink outlet and a spring configured to urge the valve member toward the sealing member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view schematically illustrating a structure of a recording apparatus. 
         FIG. 2  is a perspective view of an ink supply unit. 
         FIG. 3  is a cross-sectional view of the ink supply unit. 
         FIG. 4  is a side view of an ink refill container. 
         FIG. 5  is a perspective view of a bottle. 
         FIG. 6  is a vertical cross-sectional view of a cap and main components of the bottle. 
         FIG. 7  is a cross-sectional view of a projection and the bottle. 
         FIG. 8  is a view for explaining a change in position of the projection. 
         FIG. 9  is a view illustrating the bottle coupled to an ink refill adaptor. 
         FIG. 10  is a side view of an ink refill container according to another embodiment. 
         FIG. 11  is a perspective view of a bottle according to another embodiment. 
         FIG. 12  is a vertical cross-sectional view of a cap and main components of a bottle according to another embodiment. 
         FIG. 13  is a view for explaining a change in position of a projection according to another embodiment. 
         FIG. 14  is a view illustrating a bottle according to another embodiment coupled to an ink refill adaptor. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     A: Embodiment 
     A1: Overall Structure of Recording Apparatus 
       FIG. 1  is a perspective view schematically illustrating a structure of a recording apparatus  21  according to an embodiment. The recording apparatus  21  is an ink jet printer that ejects ink onto a medium to record, for example, an image on the medium. In  FIG. 1 , X, Y, and Z directions perpendicular to each other are indicated. The X and Y directions extend in the horizontal direction. The Z direction extends in the vertical direction. The X direction includes a +X direction and a −X direction oppositely directed. The Y direction includes a +Y direction and a −Y direction oppositely directed. The Z direction includes a +Z direction and a −Z direction oppositely directed. The +Z direction may be referred to as an upward direction. The −Z direction may be referred to as a downward direction. 
     The recording apparatus  21  includes a housing  22  having a cuboidal shape elongated in the X direction. In the housing  22 , a support board  23  elongated in the X direction is disposed at a lower side with the upper surface extending in the substantially horizontal direction. A sheet P, which is an example of the medium, is supported by the upper surface of the support board  23  and transported in the +Y direction, which is a transportation direction. In the housing  22 , a guide shaft  24  extending in the X direction is disposed above the support board  23 . The guide shaft  24  supports a carriage  26  having a recording head  25 , which ejects ink, on the lower surface. The carriage  26  is supported by the guide shaft  24  in the support hole extending through the carriage  26  in the X direction and is movable backward and forward in the X direction relative to the guide shaft  24 . 
     In the housing  22 , a driving pulley  28  and a driven pulley  29  are rotatably disposed near the ends of the guide shaft  24 . An output shaft of a carriage motor  30  is coupled to the driving pulley  28 . An endless timing belt  31  having a portion coupled to the carriage  26  is wound around the driving pulley  28  and the driven pulley  29 . When the carriage motor  30  is driven, the carriage  26  is guided by the guide shaft  24  and reciprocated in the X direction, which is a scanning direction relative to the sheet P, by the timing belt  31 . During the reciprocating, ink is ejected from the recording head  25 , which is on the lower surface of the carriage  26 , onto the sheet P that is being transported forward along the upper surface of the support board  23 . 
     The housing  22  has an outlet  32 , an outlet tray  33 , and a paper feed cassette  34  at a surface facing in the +Y direction. The sheet P recorded with ink ejected from the recording head  25  is discharged through the outlet  32 . The sheet P discharged from the housing  22  is supported by the outlet tray  33 . The paper feed cassette  34  is disposed below the outlet tray  33  and houses recording sheets P stacked in layers. 
     The housing  22  has a door  35  in the surface facing in the +Y direction at an end in the +X direction. The door  35  opens and closes about the lower end as an axis of rotation. The door  35  has a window  37  formed of a rectangular transparent member in the surface facing in +Y direction, allowing a user to visually check the inside of the housing  22 . Opening the door  35  of the housing  22  exposes an ink refill adaptor  47  of an ink supply unit  40 , which will be described later. 
     In the housing  22  of the recording apparatus  21 , the ink supply unit  40  that supplies ink to the recording head  25  is located behind the door  35 . The ink in the ink supply unit  40  is supplied through ink supply tubes  46  to the recording head  25 . The ink supply tubes  46  extending from the ink supply unit  40  are coupled to ink passages (not illustrated) in the carriage  26  and coupled to the recording head  25  through the ink passages. 
       FIG. 2  is a perspective view of the ink supply unit  40 .  FIG. 3  is a cross-sectional view of the ink supply unit  40  taken along line III-III in  FIG. 2 . As illustrated in  FIG. 2 , the ink supply unit  40  includes five ink tanks  41   a  to  41   e , five ink supply tubes  46 , and an ink refill adaptor  47 . The five ink tanks  41   a  to  41   e  store different colors of ink. Examples of the colors of ink in the ink tanks  41   a  to  41   e  include black, cyan, magenta, and yellow. In the following description, the five ink tanks  41   a  to  41   e  may be collectively referred to as the ink tank  41 . The ink tank  41  has a box-like shape elongated in the Y direction and has a cutout portion at an end in the +Z direction and +Y direction. The ink supply tubes  46  are attached to the surface of the ink tank  41  facing in the −Y direction. The cutout portions of the ink tanks  41  are called steps  48 . The ink refill adaptor  47  has a cuboidal shape and covers all the steps  48  of the five ink tanks  41   a  to  41   e  arranged in the X direction. 
     As illustrated in  FIG. 3 , the ink tank  41  includes an ink storage chamber  49  storing ink, a viewing portion  50 , and a needle  56 , in addition to the step  48 . The viewing portion  50  is a portion of the surface facing in the +Y direction of the ink storage chamber  49  of the ink tank  41  and is formed of a transparent resin. As illustrated in  FIG. 2 , the viewing portion  50  has an upper limit mark  51  and a lower limit mark  52  that respectively give indications of the upper limit and the lower limit of a liquid level in the ink storage chamber  49 . A user can fill the ink storage chamber  49  with ink without letting it overflow by using the upper limit mark  51  as a guide. A user can know the time to supply ink by using the lower limit mark  52  as a guide. The needle  56  has a substantially hollow cylindrical shape extending in the +Z direction from the surface of the step  48  extending in the XY direction. The needle  56  has a first passage  54  and a second passage  55  therein. The space in the needle  56  is separated into the first and second passages  54  and  55 . The first and second passages  54  and  55  allow communication between the ink storage chamber  49  and the outside. The upper ends of the first and second passages  54  and  55  are located below the upper surface of the ink refill adaptor  47 . In this embodiment, the upper end in the +Z direction of the first passage  54  is located below the upper end in the +Z direction of the second passage  54 . However, the first and second passages  54  and  55  may have the same height to make the upper surface of the needle  56  flat. 
     As illustrated in  FIG. 2 , the ink refill adaptor  47  includes five ink supply portions  47   a . The five ink supply portions  47   a  are disposed for the respective five ink tanks  41 . As illustrated in  FIG. 2 , the ink supply portions  47   a  each have a recess  60  and a first concave/convex portion  62 . The planar shape of the recess  60  viewed from the +Z direction is a combination of a circular shape and a rectangular shape elongated in the Y direction. The rectangular shape is symmetrical about a center line of the circular shape extending in the Y direction. As illustrated in  FIG. 3 , the recess  60  extends through the ink refill adaptor  47  in the Z direction and the end in the −Z direction of the recess  60  is closed by the surface of the step  48  extending along the XY plane. The needle  56  is disposed in the recess  60 . 
     The first concave/convex portion  62  is in the recess  60  and includes multiple bars  62   a  each having a rod-like shape extending in the +Z direction. The upper end of each bar  62   a  is located below the upper surface of the ink refill adaptor  47 . The bars  62   a  have different cross-sectional shapes and stand at different positions for the different ink tanks  41   a  to  41   e . Although the bars  62   a  of the ink supply unit  40  have different cross-sectional shapes, the same reference numeral is assigned to all the bars  62   a  for the sake of convenience in this embodiment. The same is applicable to the first concave/convex portions  62 . For example, the first concave/convex portion  62  for the ink tank  41   a  has one bar  62   a  adjacent to the needle  56  in the +Y direction and one bar  62   a  adjacent to the needle  56  in the −Y direction. The bar  62   a  adjacent to the needle  56  in the +Y direction is farther away from the needle  56  than the bar  62   a  adjacent to the needle in the −Y direction is. The first concave/convex portion  62  for the ink tank  41   b  also has two bars  62   a , but the bars  62   a  are away from the needle  56  by a substantially equal distance. The first concave/convex portions  62  for the ink tanks  41   c  to  41   e  are not described, but the first concave/convex portions  62  have the bars  62   a  having different cross-sectional shapes and located at different positions for the different ink tanks  41   c  to  41   e . During ink refill using the bottle  80 , only a bottle  80  that contains ink having a matching color for a refill target, which is any one of the ink tanks  41   a  to  41   e , fits in the ink refill portion  47   a , because the first concave/convex portions  62  have different shapes for the different ink tanks  41   a  to  41   e . The ink refill will be described later in detail. 
     A2: Structure of Ink Refill Container 
       FIG. 4  is a side view of the ink refill container  63 .  FIG. 5  is a perspective view of the bottle  80 .  FIG. 6  is a vertical cross-sectional view of the bottle  80 .  FIG. 7  is a cross-sectional view of a projection  684  and the bottle  80  and is a view taken along line VII-VII in  FIG. 4 . The ink refill container  63  is used to refill the ink supply unit  40  with ink. 
     In  FIGS. 4 to 7 , the Z direction is indicated. The Z direction includes a +Z direction and a −Z direction oppositely directed. The +Z direction may be referred to as an upward direction. The −Z direction may be referred to as a downward direction. As illustrated in  FIG. 4 , the ink refill container  63  includes the bottle  80  and a cap  68  detachably attached to the bottle  80 . The bottle  80  can store ink and has a container body  64  and an ink outlet forming portion  150  as illustrated in  FIG. 5 . 
     As illustrated in  FIG. 6 , the container body  64  has an ink housing  76 , a neck  77 , and a container screw thread  78 . As illustrated in  FIG. 4 , the container body  64  has a tubular shape with a bottom. The inner space of the container body  64  is the ink housing  76  that stores the ink. The container body  64  is formed of a transparent or semi-transparent material. Examples of the material include polypropylene. As illustrated in  FIG. 6 , the upper portion of the container body  64  has a smaller diameter. The portion having a smaller diameter is the neck  77 . The container screw thread  78  is a male thread on the outer surface of the neck  77 . 
     As illustrated in  FIG. 6 , the ink outlet forming portion  150  covers the neck  77  of the container body  64  and is detachably attached to the container body  64 . The ink outlet forming portion  150  has a substantially hollow cylindrical shape and includes an outer peripheral portion  70 , a small-diameter portion  66 , an ink outlet  65 , a spout screw thread  82 , a first screw thread  69 , a slit valve  74  as a valve, and a first protrusion  91 . The outer peripheral portion  70  is a lower portion of the ink outlet forming portion  150  and has a larger diameter than the neck  77 . The outer peripheral portion  70  has the spout screw thread  82  on the inner surface. The spout screw thread  82  is a male thread engaging with the container screw thread  78  on the container body  64 . The outer peripheral portion  70  has the first screw thread  69  on the outer surface. The small-diameter portion  66  is located above the outer peripheral portion  70 . The small-diameter portion  66  has a smaller inner diameter than the outer peripheral portion  70 . The ink outlet  65  having a tubular shape is located on the upper end of the small-diameter portion  66 . 
     In addition to the above, as illustrated in  FIG. 5 , the ink outlet forming portion  150  has two convex portions  71 , two second concave/convex portions  72 , and a positioning portion  73 . The two convex portions  71  and the two second concave/convex portions  72  are located outwardly from the small-diameter portion  66  in the radial direction. The two convex portions  71  each have a wall extending in the radial direction of the small-diameter portion  66  and a portion extending in the circumferential direction of the small-diameter portion  66  from the leading end in the radial direction of the wall. The two second concave/convex portions  72  extend from the two convex portions  71  in a direction intersecting the walls of the two convex portions  71  or in the circumferential direction of the small-diameter portion  66 . The two convex portions  71  extend from the outer peripheral portion  70  in the +Z direction. Specifically described, when viewed in the Z direction, the two convex portions  71  are point symmetrical about the center axis CX and the two second concave/convex portions  72  are point symmetrical about the center axis CX. The two convex portions  71  are configured to fit in the ink refill adaptor  47 . The two convex portions  71  each have the second concave/convex portion  72  between the outer end in the radial direction of the small-diameter portion  66  and the inner end adjacent to the small-diameter portion  66 . As illustrated in  FIG. 7 , when viewed in the Z direction, the second concave/convex portion  72  has a cutout in each surface extending in the diametrical direction to fit with the first concave/convex portion  62 . The second concave/convex portions  72  have different shapes for different colors of ink in the bottles  80 . The second concave/convex portion  72  in  FIG. 7  is shaped to fit the first concave/convex portion  62  of the ink tank  41   b . Specifically described, the second concave/convex portions  72  have predetermined shapes for different colors of ink in the bottles  80 . The shapes are designed to fit the first concave/convex portions  62  having predetermined shapes for different ink colors. As illustrated in  FIG. 5 , the positioning portion  73  is disposed on substantially the center in the Z direction of the small-diameter portion  66 . The positioning portion  73  has a ring-shaped portion and portions extending from the ends in the diametrical direction of the ring-shaped portion to the two convex portions  71 . As illustrated in  FIG. 7 , when viewed in the Z direction, the positioning portion  73  has a portion protruding outwardly from the outer edge of each of the small-diameter portion  66 , the second concave/convex portion  72 , and the convex portion  71 . When the bottle  80  is inserted into the ink refill portion  47   a  for ink refill, the positioning portion  73  comes in contact with the upper surface of the ink refill adaptor  47  at the outer edge in the short-side direction of the recess  60  or in the X direction, and thus the bottle  80  is positioned in the direction along the center axis CX. 
     As illustrated in  FIG. 6 , the slit valve  74  is disposed in the opening of the ink outlet  65  and is configured to open and close the passage in the ink outlet  65  to control the ink flow. As illustrated in  FIG. 7 , the slit valve  74  has a valve member  742  formed of an elastic material such as silicone. The valve member  742  has a circular plan shape when viewed in the Z direction and is segmented by at least one slit  75  extending outwardly from the center of the ink outlet  65  in the radial direction. In this embodiment, the valve member  742  is segmented by six slits  75 . When receiving no external force, the slits  75  are closed and thus the slit valve  74  is closed. When receiving an external force, the slits  75  of the valve member  742  are pushed and opened and thus the slit valve  74  is opened. As illustrated in  FIG. 7 , the two first protrusions  91  protrudes inwardly in the radial direction from a second inner peripheral portion  65   a  of the ink outlet  65 . The first protrusions  91  are, as illustrated in  FIG. 6 , located outwardly from the slit valve  74  in the direction along the center axis CX of the ink outlet  65 . 
     As illustrated in  FIG. 6 , the cap  68  is detachably attached to the ink outlet forming portion  150  to cover the ink outlet forming portion  150 . The cap  68  has a trunk  682 , a top portion  683 , a top protrusion  683   a , a projection  684 , a second screw thread  681 , and a third screw thread  685 . 
     The trunk  682  has a tubular shape. The inner diameter of the trunk  682  is larger than the outer diameter of the outer peripheral portion  70 . The trunk  682  has a first inner peripheral portion  682   a  facing the ink outlet forming portion  150 . The first inner peripheral portion  682   a  has the second screw thread  681  at an end in the −Z direction. The second screw thread  681  is a female thread configured to engage with the first screw thread  69 . The top portion  683  covers the end in the +Z direction of the trunk  682 . The top portion  683  faces the ink outlet  65  of the bottle  80  with the cap  68  being attached to the ink outlet forming portion  150 . The top portion  683  has the third screw thread  685 . Specifically described, the top protrusion  683   a  protrudes from a surface of the top portion  683  facing the ink outlet  65  toward the ink outlet  65 . The top protrusion  683   a  has a recess extending in the +Z direction along the center axis CX and the recess has the third screw thread  685  on the inner surface. 
     The projection  684  extends in a direction along the center axis CX of the trunk  682 . The projection  684  has a substantially hollow cylindrical shape. The projection  684  is screwed to the cap  68  with the center axis of the projection  684  being along the center axis CX of the top portion  683 . The projection  684  has a side wall  688  as an outer surface, a fourth screw thread  686 , and two second protrusions  687 . The fourth screw thread  686  is a male thread on an end in the +Z direction of the side wall  688  and is configured to engage with the third screw thread  685 . The two second protrusions  687  protrude in the radial direction from an end in the −Z direction of the side wall  688 . The engagement of the fourth screw thread  686  with the third screw thread  685  allows the projection  684  to move in the direction along the center axis CX relative to the cap  68 . 
     In this embodiment, the first screw thread  69  and the second screw thread  681  are engaged with each other by clockwise rotation of the cap  68  relative to the bottle  80 , which is called a right-hand thread. The third screw thread  685  and the fourth screw thread  686  are engaged with each other by counterclockwise rotation of the cap  68  relative to the projection  684 , which is called a left-hand thread. The pitch P 2  of the third and fourth screw threads  685  and  686  is larger than the pitch P 1  of the first and second screw threads  69  and  681 . This makes the movement distance of the projection  684  larger for the rotated amount of the cap  68  than a configuration in which the pitch P 1  and the pitch P 2  are the same. 
     As illustrated in  FIG. 7 , when viewed in the Z direction, the two first protrusions  91  are point symmetrical about the center axis CX. The first protrusions  91  each have two wall surfaces that form a substantially right angle. The two second protrusions  687  of the projection  684  are on both sides of the center axis CX and on the same line passing through the center axis CX. The second protrusions  687  each have two wall surfaces substantially parallel to each other. When the second screw thread  681  of the cap  68  engages with the first screw thread  69  of the bottle  80 , one of the two first protrusions  91  and one of the two second protrusions  687  are in contact with each other. In addition, the other of the two first protrusions  91  and the other of the two second protrusions  687  are in contact with each other. This does not allow the projection  684  to rotate relative to the bottle  80  when the cap  68  is rotated relative to the bottle  80  in any of the clockwise direction and the counterclockwise direction. 
     A3: Ink Refill Using Ink Refill Container 
     When the amount of ink in the ink tank  41  is small, the user refills the ink tank  41  with ink by using the ink refill container  63 . Specifically described, first, the user removes the cap  68  from the ink refill container  68  to expose the ink outlet forming portion  150 . The movement of the projection  684  during the removal of the cap  68  from the ink refill container  63  will be described. 
       FIG. 8  is a view for explaining how the position of the projection  684  relative to the top portion  683  changes when the cap  68  is attached or detached. In the left view in  FIG. 8 , the cap  68  is attached to the ink outlet forming portion  150 . In the right view in  FIG. 8 , the cap  68  is unscrewed from the ink outlet forming portion  150 . When the cap  68  screwed to the ink outlet forming portion  150  is rotated relative to the ink outlet forming portion  150  in the counterclockwise direction or a first direction in which the engagement between the first and second screw threads  69  and  681  is cancelled, the first and second screw threads  69  and  681  are disengaged from each other. During the rotation of the cap  68  in the counterclockwise direction, the second protrusion  687  of the projection  684  comes in contact with the first protrusion  91 , restricting the rotation of the projection  684  about the center axis CX. Then, the contact between the second protrusion  687  and the first protrusion  91  allows relative rotation of the projection  684  in the clockwise direction or the second direction opposite to the first direction. The relative rotation allows the projection  684  to move toward the valve member  742 , and the projection  684  pushes the valve member  742  and enters the slit  75 . Specifically described, the rotation of the third screw thread  685  in the counterclockwise direction guides the fourth screw thread  686  to the thread groove of the third screw thread  685 . This moves the projection  684  toward the valve member  742 . As illustrated in the right view in  FIG. 8 , the projection  684  opens the slit valve  74  and releases the pressure from the ink container  76 . 
     In contrast, when the cap  68  is rotated in the clockwise direction or the second direction in which engagement between first screw thread  69  and the second screw thread  681  is established, the first and second screw threads  69  and  681  are engaged. When the cap  68  is rotated in the clockwise direction, in which engagement between the first and second screw threads  69  and  681  is established, the second protrusion  687  comes in contact with the first protrusion  91 . The contact allows the projection  684  to relatively rotate in the first direction and move away from the valve member  742 . The valve member  742  is closed when the projection  684  is moved away from the valve member  742 . As illustrated in the left view in  FIG. 8 , with the cap  68  being attached to the ink outlet forming portion  150 , the projection  684  does not deform the valve member  742 , and thus the valve member  742  is unlikely to be subjected to creep deformation. If the valve member  742  is subjected to creep deformation, ink may drip from the valve member  742  when the bottle  80  is turned upside down. The suppression of creep deformation of the valve member  742  reduces the ink dripping from the bottle  80  turned upside down. 
     In the ink refilling using the ink refill container  63 , after removing the cap  68  from the bottle  80 , the user turns the bottle  80  upside down and puts the exposed convex portions  71  of the bottle  80  in the recess  60  of the ink supply unit  40 . At this time, if the inner pressure of the ink container  76  is high and the inner pressure of the ink container  76  is not sufficiently released, the sum of the inner pressure and the hydraulic head pressure of the ink would exceed the pressure resistance of the valve member  742  when the bottle  80  is turned upside down. In such a case, the ink may spurt. For example, the pressure in the ink refill container  63  increases if the temperature has increased since the last time the cap  68  was being attached. However, in this embodiment, as described above, the projection  684  enters the valve member  742  to release the pressure from the ink refill container  63  when the cap  68  is removed from the bottle  80 . Thus, the ink is unlikely to spurt when the ink refill container  63  is turned upside down. 
       FIG. 9  illustrates the bottle  80  turned upside down and inserted into the ink refill adaptor  47 . As described above, the second concave/convex portion  72  of the bottle  80  is shaped to fit the first concave/convex portion  62  for a corresponding ink color. When the color of the ink in the bottle  80  matches the color of ink in the ink tank  41  to be refilled, as illustrated in  FIG. 9 , the user can put the bottle  80  in the ink refill adaptor  47 . This prevents the user from supplying wrong color of ink. The user inserts the bottle  80  until the positioning portion  73  comes in contact with the upper surface of the ink refill adaptor  47 . The insertion of the bottle  80  allows the needle  56  to open the slit valve  74 . One of the first and second passages  54  and  55  becomes a flow passage of ink and the other becomes a flow passage of air. Of the first and second passages  54  and  55 , one that touched ink first at the opening end becomes the flow passage of ink, and one that did not touch the ink becomes the flow passage of air. Opening of the slit valve  74  allows ink in the bottle  80  to flow to the ink tank  41  through the first passage  54  or the second passage  55 . After completion of the refill, the user pulls the bottle  80  out of the ink refill adaptor  47  and puts the cap  68  on the bottle  80 . When the cap  68  is attached to the bottle  80  as described above, the projection  684  of the cap  68  is moved away from the valve member  742 . In  FIGS. 3 and 9 , the first and second passages  54  and  55  have different heights, but the first and second passages  54  and  55  may have the same height. 
     According to the above-described embodiment, when the cap  68  is rotated in the first direction in which the engagement between the first and second screw threads  69  and  681  is cancelled, the projection  684  moves to the valve member  742  to push the valve member  742  and enters the slit  75 . The projection  684  pushing the valve member  742  releases the pressure from the bottle  80 . In contrast, when the cap  68  is rotated in the second direction, in which engagement between the first and second screw threads  69  and  681  is established, the projection  68  is relatively rotated in the first direction to be away from the valve member  742 . This reduces creep deformation of the valve member  742 , because the projection  684  is positioned away from the valve member  742 . Furthermore, the rotation of the cap  68  in the first direction allows the second protrusion  687  to come in contact with the first protrusion  91 . This allows the projection  684  to relatively rotate in the second direction and move toward the valve member  742  until the projection  684  pushes the valve member  742  and enters the slit  75 . In contrast, the rotation of the cap  68  in the second direction allows the second protrusion  687  to come in contact with the first protrusion  91 . This allows the projection  684  to relatively rotate in the first direction to be away from the valve member  742 . In this configuration, when the cap  68  is rotated in the first direction relative to the bottle  80 , the projection  684  pushes the valve member  742 . When the cap  68  is rotated in the second direction relative to the bottle  80 , the projection  684  moves away from the valve member  742 . Furthermore, the pitch P 2  of the third and fourth screw threads  685  and  686  may be larger than the pitch P 1  of the first and second screw threads  69  and  681 . This makes the movement distance of the projection  684  larger for the rotated amount of the cap  68  than a configuration in which the pitch P 2  is equal to or smaller than the pitch P 1 . 
     B: Modifications 
     B1: First Modification 
     In the above-described embodiment, the first and second screw threads  69  and  681  are right-hand threads, and the third and fourth screw threads  685  and  686  are left-hand threads. However, the first and second screw threads  69  and  681  may be left-hand threads, and the third and fourth screw threads  685  and  686  may be right-hand threads. The first and second screw threads  69  and  681  and the third and fourth screw threads  685  and  686  have inverted screw structures. This enables the projection  684  to move backward and forward by the rotation of the cap  68  relative to the bottle  80 . 
     B2. Second Modification 
     In the above-described embodiment, the two first protrusions  91  protrude from the ink outlet  65 . The first protrusions  91  have two wall surfaces that form a substantially right angle. The shape of the first protrusion  91  may be modified. The first protrusion  91  may have any shape that protrudes from the second inner peripheral portion  65   a  of the ink outlet  65  toward the center axis CX. The projection  684  has the two second protrusions  687 . The shapes of the first and second protrusions  91  and  687  are not limited to those in the above-described embodiment. For example, the number of first protrusions  91  and the number of second protrusions  687  each may be one, or the first protrusion  91  and the second protrusion  687  may engage with each other in the vertical direction. 
     B3: Third Modification 
     In the above-described embodiment, the projection  684  is moved backward and forward by the rotation of the cap  68  relative to the bottle  80  because the projection  684  is attached to the top portion  683  by engagement between the third screw thread  685  and the fourth screw thread  686 . However, the structure for moving the projection  684  backward and forward by the rotation of the cap  68  relative to the bottle  80  is not limited to that in the above-described embodiment. For example, a structure of cam may be employed to convert rotation motion of the cap  68  to reciprocating motion in the direction along the center axis CX. 
     C: Other Forms 
     The present disclosure is not limited to the embodiment described above and may be embodied in various forms without departing from the spirit of the disclosure. For example, the present disclosure may be achieved in the forms below. To solve partially or entirely the problems described above or to achieve partially or entirely the effects described above, the technical features of the above-described embodiment may be replaced or combined as appropriate with corresponding technical features of the configurations described below. Furthermore, the technical feature(s) may be eliminated as appropriate if the technical feature(s) are not described as essential in this specification. 
     (1) According to another aspect of the present disclosure, an ink refill container is provided. The ink refill container includes a bottle configured to store ink and a cap detachably attached to the bottle. The bottle includes: an ink outlet forming portion that has a tubular ink outlet and an outer peripheral portion having a first screw thread; and a valve that includes a valve member formed of an elastic material and disposed in the ink outlet. The valve member is segmented by at least one slit. The cap includes: a tubular trunk that has a first inner peripheral portion having a second screw thread configured to engage with the first screw thread; a top portion that faces the ink outlet with the cap being attached to the bottle; and a projection that extends along a center axis of the trunk. The projection is configured to move toward the valve member until the projection pushes the valve member and enters the slit to open the valve member when the cap is rotated in a first direction in which engagement between the first screw thread and the second screw thread is cancelled. The projection is configured to relatively rotate in the first direction and move away from the valve member to close the valve member when the cap is rotated in a second direction in which engagement between the first screw thread and the second screw thread is established. In this configuration, when the cap is rotated in the first direction relative to the bottle, the projection pushes the valve member. This releases the pressure from the bottle. In contrast, when the cap is rotated in the second direction relative to the bottle, the projection moves away from the valve member. This reduces creep deformation of the valve member. 
     (2) In the ink refill container having the above-described configuration, the bottle may further have a first protrusion protruding from a second inner peripheral portion of the ink outlet, and the cap may further include a third screw thread on the top portion. The projection may include a side wall having a fourth screw thread configured to engage with the third screw thread; and a second protrusion protruding from the side wall. The projection may be configured to relatively rotate in the second direction and move toward the valve member until the projection pushes the valve member and enters the slit when the second protrusion is brought into contact with the first protrusion by rotation of the cap in the first direction. The projection may be configured to relatively rotate in the first direction to move away from the valve member when the second protrusion is brought into contact with the first protrusion by rotation of the cap in the second direction. In this configuration, when the cap is rotated in the first direction, the second protrusion comes in contact with the first protrusion. The contact allows the projection to relatively rotate in the second direction and to move toward the valve member. When the cap is rotated in the second direction, the second protrusion comes in contact with the first protrusion. The contact allows the projection to rotate in the first direction and to move away from the valve member. In this configuration, when the cap is rotated in the first direction relative to the bottle, the projection pushes the valve member. This releases the pressure from the bottle. Furthermore, when the cap is rotated in the second direction relative to the bottle, the projection is moved away from the valve member. This reduces creep deformation of the valve member. 
     (3) In the ink refill container having the above-described configuration, a pitch of the third and fourth screw threads may be larger than that of the first and second screw threads. This configuration increases the movement distance of the projection, which corresponds to the rotated amount of the cap, compared with a configuration in which the pitch of the third and fourth screw threads is equal to or smaller than the pitch of the first and second screw threads. 
     The components in the above-described embodiment, modifications, and forms of this disclosure are not all essential. To solve partially or entirely the problems described above or to achieve partially or entirely the effects described above, one or more of the components may be altered, eliminated, replaced with another component, or the features of the components may be partly eliminated, as appropriate. Furthermore, to solve partially or entirely the problems described above or to achieve partially or entirely the effects described above, a part or all of the technical features of one of the above-described embodiment, modifications, and forms of this disclosure may be combined with a part or all of the technical features of different one of the above-described embodiment, modifications, and forms of this disclosure to form another form of the present disclosure. 
     D: Another Embodiment 
     Next, an ink refill container  63 A according to another embodiment will be described. Components identical to those in the above-described embodiment are assigned the same reference numerals and are not repeatedly described. 
     As illustrated in  FIG. 10 , an ink refill container  63 A includes a bottle  80 A configured to store ink and a cap  68 A detachably attached to the bottle  80 A. As illustrated in  FIG. 11 , the bottle  80 A includes a container body  64 A and an ink outlet forming portion  150 A. 
     As illustrated in  FIG. 12 , the container body  64 A has an ink housing  76 , a neck  77 , and a container screw thread  78 . The container body  64 A is a container having a tubular shape with a bottom. The inner space of the container body  64 A is the ink housing  76  that stores ink. 
     The ink outlet forming portion  150 A covers the neck  77  of the container body  64 A and is detachably attached to the container body  64 A. The ink outlet forming portion  150 A has a substantially hollow cylindrical shape and has an outer peripheral portion  70 , a small-diameter portion  66 , an ink outlet  65 , a spout screw thread  82 , a first screw thread  69 , a valve  174 , and a first protrusion  91 . 
     The valve  174  is disposed in the opening of the ink outlet  65 . The valve  174  opens and closes the passage in the ink outlet  65  to control the ink flow. The valve  174  of this embodiment has a valve case  845  having a tubular shape. The valve case  845  is disposed in the opening of the ink outlet  65 . A sealing member  843 , the valve member  842 , and a spring  844  are housed in the valve case  845 . The sealing member  843  has a tubular shape and is attached to the inner peripheral portion of the ink outlet  65 . The sealing member  843  is formed of an elastic material such as silicone. A protuberance  843   a  protrudes from the inner surface of the sealing member  843  toward the center axis CX. The valve member  842  is located below the sealing member  843  and is configured to move in the Z direction relative to the sealing member  843 . Specifically described, the valve member  842  is configured to move to or away from the sealing member  843 . The valve member  842  is urged by the spring  844  toward the sealing member  843 . The valve case  845  has an opening  845   a  extending in the Z direction in the circumferential surface. The opening  845   a  is a through hole extending through the side wall of the valve case  845  in the radial direction through the center axis CX. 
     The valve member  842  has a planar portion  842   b  that comes in contact with the sealing member  843 . When the surface of the sealing member  843  facing in the −Z direction and the surface of the planar portion  842   b  facing in the +Z direction are in contact with each other, the passage in the ink outlet  65  is closed. When the surface of the sealing member  843  facing in the −Z direction and the surface of the planar portion  842   b  facing in the +Z direction are away from each other, the ink outlet  65  and the ink housing  76  are in communication with each other through the opening  845   a  (atmosphere communication) and the passage of the ink outlet  65  is opened. 
     The valve member  842  has a protrusion  842   a  protruding from the planar portion  842   b  in the +Z direction. The protrusion  842   a  faces the projection  684 . The spring  844  is a coil spring, for example. The end in the −Z direction of the spring  844  is supported by the valve case  845  and the end in the +Z direction of the spring  844  is in contact with the valve member  842  to support the valve member  842 . The force of the spring  844  in the +Z direction causes the valve member  842  to come in contact with the sealing member  843 , and thus the passage in the ink outlet  65  is closed. The valve member  842  receiving no external force is closed because the sealing member  843  and the valve member  842  are in contact with each other. When an external force is applied to the valve member  842  in the −Z direction, the valve member  842  is moved down in the −Z direction relative to the sealing member  843 . Thus, the sealing member  843  and the valve member  842  are away from each other, and thus the valve member  842  is opened. 
     The cap  68 A is detachably attached to the ink outlet forming portion  150 A to cover the ink outlet forming portion  150 A. The cap  68 A has a trunk portion  682 , a top portion  683 , a top protrusion  683   a , a projection  684 , a second screw thread  681 , and a third screw thread  685 . The projection  684  is movable backward and forward in the direction along the center axis CX relative to the cap  68 A. 
     When the amount of ink in the ink tank  41  is small, the user refills the ink tank  41  with ink by using the ink refill container  63 A. Specifically described, the user removes the cap  68 A from the ink refill container  63 A to expose the ink outlet forming portion  150 A. 
     The movement of the projection  684  during the removal of the cap  68 A from the ink refill container  63 A is described.  FIG. 13  is a view for explaining how the position of the projection  684  relative to the top portion  683  changes when the cap  68 A is attached or detached. In the left view in  FIG. 13 , the cap  68 A is attached to the ink outlet forming portion  150 A. In the right view in  FIG. 13 , the cap  68 A is unscrewed from the ink outlet forming portion  150 A. When the cap  68 A screwed to the ink outlet forming portion  150 A is rotated relative to the ink outlet forming portion  150 A in the counterclockwise direction or the first direction in which the engagement between the first and second screw threads  69  and  681  is cancelled, the first and second screw threads  69  and  681  are disengaged from each other. During the rotation of the cap  68 A in the counterclockwise direction, the second protrusion  687  of the projection  684  comes in contact with the first protrusion  91 , restricting the rotation of the projection  684  about the center axis CX. Then, the contact between the second protrusion  687  and the first protrusion  91  allows the projection  684  to relatively rotate in the clockwise direction or the second direction opposite to the first direction. The relative rotation moves the projection  684  toward the protrusion  842   a  of the valve member  842 , and the projection  684  comes in contact with the protrusion  842   a  to push the protrusion  842   a  (valve member  842 ) downward (−Z direction). Specifically described, the rotation of the third screw thread  685  in the counterclockwise direction guides the fourth screw thread  686  to the thread groove of the third screw thread  685 . This moves the projection  684  toward the valve member  842 . Specifically described, as illustrated in the right view in  FIG. 13 , the projection  684  resists the force of the spring  844  and moves the valve member  842  in the −Z direction. In this state, the valve member  842  and the sealing member  843  are away from each other and the valve  174  is opened through the opening  845   a . This releases the pressure from the ink container  76 . 
     In contrast, when the cap  68 A is rotated relative to the ink outlet forming portion  150 A in the clockwise direction or the second direction, in which engagement between the first screw thread  69  and the second screw thread  681  is established, the first screw thread  69  and the second screw thread  681  are engaged. The rotation in the clockwise direction, in which engagement between the first screw thread  69  and the second screw thread  681  is established, allows the second protrusion  687  to come in contact with the first protrusion  91 . Thus, the projection  684  is relatively rotated in the first direction to be away from the valve member  842 . Since the projection  684  is moved away from the valve member  842 , the sealing member  843  comes in contact with the valve member  842  and the valve  174  is closed. As illustrated in the left view in  FIG. 13 , with the cap  68 A being attached, the projection  684  is away from the valve member  842  and the projection  684  does not apply a pressure to the valve member  842 . This reduces creep deformation of the valve member  842 . If the valve member  842  is subjected to creep deformation, ink may drip from the valve member  842  when the bottle  80 A is turned upside down. In this embodiment, the suppression of creep deformation of the valve member  842  reduces the ink dripping from the bottle  80 A turned upside down. 
     In the ink refilling with the ink refill container  63 A, after removing the cap  68 A from the bottle  80 A, the user turns the bottle  80 A upside down and puts the exposed convex portions  71  of the bottle  80 A in the recess  60  of the ink supply unit  40 . At this time, if the inner pressure of the ink container  76  is high and the pressure in the ink container  76  is not sufficiently released, the sum of the inner pressure and the hydraulic head pressure of the ink would exceed the pressure resistance of the valve member  842  when the bottle  80 A is turned upside down. In such a case, the ink may spurt. For example, the pressure in the ink refill container  63 A increases if the temperature has increased since the last time the cap  68 A was being attached. However, in this embodiment, as described above, the projection  684  pushes the valve member  842  and opens the valve  174  to release the pressure from the ink housing  76  when the cap  68 A is removed from the bottle  80 A. Thus, the ink is unlikely to spurt when the ink refill container  63 A is turned upside down. 
       FIG. 14  illustrates the bottle  80 A placed upside down and inserted into the ink tank  41 . The insertion of bottle  80 A allows the needle  56  to push the valve member  842  and opens the valve  174 . One of the first and second passages  54  and  55  becomes the passage of ink, and the other becomes the passage of air. After the valve  174  is opened, the ink in the bottle  80 A is supplied to the ink tank  41  through the first passage  54  or the second passage  55 . When the bottle  80 A is inserted in the ink tank  41 , the protuberance  843   a  of the sealing member  843  comes in contact with the outer surface of the needle  56 . This keeps the ink outlet  65  closed and prevents the ink leakage. On completion of refilling, the user removes the bottle  80 A from the ink tank  41  and puts the cap  68 A on the bottle  80 A. As described above, when the cap  68 A is attached to the bottle  80 A, the projection  684  of the cap  68 A is moved away from the valve member  842 . 
     According to this embodiment, when the cap  68 A is rotated in the first direction, in which the engagement between the first and second screw threads  69  and  681  is cancelled, the projection  684  moves toward the valve member  842  to push the valve member  842  downward. This opens the valve  174  and releases the pressure from the bottle  80 A. In contrast, when the cap  68 A is rotated in the second direction, in which engagement between the first screw thread  69  and the second screw thread  681  is established, the projection  684  is relatively rotated in the first direction to be away from the valve member  842 . This reduces creep deformation of the valve member  842 . This configuration is less likely to have the problem of ink leakage through the slit  75 , which may be caused by creep deformation, than the configuration including the slit valve  74 . Furthermore, in this embodiment, the spring  844  applies a load for a temporary period unlike in the configuration in which the projection  684  of the cap  68 A opens the valve  174  all the time. When a stress generated by the load for opening the valve is continuously applied to a portion where the ink is attached, the portion may be readily subjected to chemical cracking. However, the spring load caused during valve opening is only temporary applied, and thus the chemical cracking is likely to be avoided. 
     In the above-described embodiments of the ink refill containers  63  and  63 A, the configurations of the slit valve  74  as the valve and the valve  174  having the spring  844  were described, but the present disclosure is not limited to these configurations. The valve may have any structure that opens and closes in response to the movement of the projection  684 . For example, the ink refill container may have any configuration as long as the projection  684  moves toward the valve and pushes the valve member to open the valve when the cap  68  is rotated in the first direction, in which engagement between the first and second screw threads  69  and  681  is cancelled, and the projection  684  is relatively rotated in the first direction to be away from the valve member to close the valve when the cap  68  is rotated in the second direction, in which engagement between the first and second screw threads  69  and  681  is established. With this configuration, when the cap  68  is rotated in the first direction relative to the bottle  80 , the projection  684  pushes the valve member, and thus the pressure in the bottle  80  is released. When the cap  68  is rotated in the second direction relative to the bottle  80 , the projection  684  moves away from the valve member. This reduces deformation of the valve member or a load continuously applied to a member that opens the valve. In particular, when a stress is continuously applied by a continuous load to a portion where ink is attached, the portion is likely to be subjected to chemical cracking. However, the above-described configurations reduce the possibility.