Patent Publication Number: US-9895900-B2

Title: Liquid cartridge having structure for opening and closing liquid channel and air channel

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority from Japanese Patent Application Nos. 2015-143965 filed Jul. 21, 2015, 2015-143966 filed Jul. 21, 2015 and 2015-143968 filed Jul. 21, 2015. The entire contents of these priority applications are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a liquid cartridge configured to store liquid therein that can be flow out therefrom. 
     BACKGROUND 
     An inkjet-recording device well known in the art has a recording head and is configured to record images on sheets by ejecting ink stored in an ink cartridge onto the sheets through nozzles formed in the recording head. When ink in the ink cartridge is consumed through image-recording operations performed by the inkjet-recording device, the empty ink cartridge is removed and replaced with a new ink cartridge filled with ink. 
     One ink cartridge known in the art has an ink supply chamber that can provide communication between an ink chamber storing ink and the exterior of the ink cartridge. One end of the ink supply chamber is in communication with the ink chamber, while the other end is in communication with the exterior of the ink cartridge through an ink outlet. Within the ink supply chamber, a valve member is disposed. The valve member can move to open and close the ink outlet, controlling whether ink stored in the ink chamber can be supplied out of the ink cartridge. The ink cartridge having this construction is described in Japanese Patent Application Publication No. 2006-62377. 
     Another conventional ink cartridge includes an ink supply part for supplying ink through an ink channel, and an air communication part that can provide communication between a layer of air in an ink chamber that stores ink and the exterior of the ink cartridge through an air channel. The air communication part is closed when the ink cartridge is stored so that the ink chamber is kept enclosed. When the ink cartridge is mounted in an inkjet-recording device, the air communication part is opened so that the ink chamber can communicate with external air. 
     Japanese Patent No. 4506301 discloses an ink cartridge that employs a single valve mechanism for opening and closing both the ink channel and the air channel. 
     Japanese Patent Application Publication No. 2003-300330 describes an ink cartridge having a structure that opens the air communication part to external air before the ink supply part can communicate with the recording head. The air communication part is preferably opened to the external air before the ink supply unit is in communication with the recording head. This is because, if the air communication part were to be opened to the external air after the ink supply part becomes in communication with the recording head when the ink cartridge is in a high-altitude region in which the atmospheric pressure is lower than the internal pressure of the ink chamber, an excessive amount of ink may be supplied from the ink chamber to the recording head, causing ink meniscus in individual nozzles of the recording head to break. 
     SUMMARY 
     In some cases, the valve member provided within the ink supply chamber may have a lengthy moving range. For example, the valve member may need to move over a longer range when functioning, not only to open and close the ink outlet, but also to open and close the air channel providing communication between the layer of air in the ink chamber and the exterior of the ink cartridge. The moving range of the valve member may also be made longer in an ink cartridge that can prevent outflow of ink when the ink outlet is opened due to unintentional movement of the valve member. This ink cartridge may be configured to prevent the ink outlet from being opened when the valve member moves only a short distance and to allow the ink outlet to open only when the valve member has moved a prescribed distance. 
     In order to ensure that the valve member can be moved reliably over a longer range, it is preferable that the valve member be surrounded by a frame that defines the ink supply chamber. Accordingly, when manufacturing the ink cartridge through resin-molding, a hollow region should be formed in a molded product (i.e., the frame) with a length adequate for the moving range of the valve member. 
     When molding the ink cartridge with resin, a pin is disposed in a die in an area that will become the hollow region for the valve member. If the hollow region must be long as in the cases described above, there is a higher probability that the pin will become tilted during a molding step in a cartridge manufacturing process due to pressure applied by resin when the resin is poured into the die. If the pin becomes tilted, the area defining the ink supply chamber in the ink cartridge cannot be molded precisely. 
     In view of the foregoing, it is an object of the present disclosure to provide a liquid cartridge whose parts that define the space for accommodating the valve member can be precisely molded, even when the valve member has a considerably long moving range. 
     Further, in the conventional ink cartridge using a single valve mechanism to open and close both the ink channel and air channel, there is a need to more reliably supply ink out of the ink cartridge from the ink chamber through the ink channel opened by the valve mechanism. 
     In view of the foregoing, it is another object of the present disclosure to provide a liquid cartridge capable of more reliably supplying liquid stored in a liquid chamber out of the liquid cartridge. 
     Further, in the conventional ink cartridge described in Japanese unexamined patent application publication No. 2003-300330, a problem may arise if the ink cartridge is mounted in the inkjet-recording head at a high speed. That is, even when the air communication part is opened to the external air before the ink supply part communicates with the recording head, there is a chance that the ink supply part will be able to communicate with the recording head before the internal pressure of the ink chamber becomes equalized with the atmospheric pressure. If the ink supply part communicates with the recording head before the pressure in the ink chamber becomes equal to the atmospheric pressure, an excessive amount of ink may be supplied from the ink chamber to the recording head, breaking the ink meniscus in individual nozzles of the recording head. 
     In view of the foregoing, it is still another object of the present disclosure to provide a liquid cartridge capable of preventing liquid stored in a liquid chamber from flowing out of the chamber due to its internal pressure. 
     In order to attain the above and other objects, the present disclosure provides a liquid cartridge including a resin frame, a valve and a wall member. The frame defines: a portion of a liquid chamber configured to store liquid; and a portion of a valve chamber in communication with the liquid chamber, the valve chamber extending in a first direction away from the liquid chamber and having one end in the first direction at which a liquid outlet is provided to provide communication between the valve chamber and an outside of the liquid cartridge, the frame having a wall portion defining a portion of the valve chamber. The valve is disposed within the valve chamber and is movable in a second direction opposite the first direction, the valve having a closing part configured to open and close the liquid outlet in accordance with movement of the valve. The wall member defines the valve chamber together with the wall portion of the frame. 
     According to another aspect, the present disclosure provides a liquid cartridge including: a liquid chamber configured to store liquid therein; a valve chamber in communication with the liquid chamber; a liquid outlet; a first air channel; a second air channel; a valve; a first sealing part; a second sealing part; a third sealing part; and a liquid channel. The valve chamber is defined at least by a base wall surface and a peripheral wall surface, the peripheral wall surface extending in a first direction away from the liquid chamber and having an annular-shaped cross-section taken along a plane orthogonal to the first direction, the peripheral wall surface being formed with a first opening and a second opening, the second opening being positioned further in a second direction opposite the first direction relative to the first opening. The liquid outlet is provided at one end of the valve chamber in the first direction to provide communication between the valve chamber and outside of the liquid chamber. The first air channel connects the first opening and an outside of the liquid cartridge to provide communication between the valve chamber and ambient air. The second air channel connects the second opening and the liquid chamber to provide communication between the liquid chamber and the valve chamber. The valve is movably disposed within the valve chamber, the valve having a closing part configured to open and close the liquid outlet in accordance with movement of the valve, the valve being formed with a through-hole extending in the first direction. The first sealing part is provided on an outer surface of the valve and has an annular shape when viewed in the first direction, the first sealing part being configured to be in close contact with the peripheral wall surface and slide relative thereto in accordance with movement of the valve. The second sealing part is provided on the outer surface of the valve and has an annular shape when viewed in the first direction, the second sealing part being positioned further in the first direction relative to the first sealing part, the second sealing part being configured to be in close contact with the peripheral wall surface and slide relative thereto in accordance with the movement of the valve. The third sealing part is provided on the outer surface of the valve, the third sealing part being positioned further in the second direction relative to the first sealing part, the third sealing part being configured to be in close contact with the peripheral wall surface and slide relative thereto in accordance with the movement of the valve. The liquid channel connects between the liquid chamber and the liquid outlet via the through-hole formed in the valve. The valve is movable, in the first direction and in the second direction, between a first state and a second state. In the first state, the closing part closes the liquid outlet; the first sealing part is positioned between the first opening and the second opening to interrupt air flow between the first opening and the second opening; the second sealing part is positioned further in the first direction relative to the first opening; the third sealing part interrupts liquid flow between the second opening and the liquid channel. In the second state, the closing part opens the liquid outlet; and the first opening and the second opening are positioned between the first sealing part and the second sealing part to provide air flow between the first opening and the second opening. The valve at the second state is positioned further in the second direction relative to the valve at the first state. 
     According to still another aspect, the present disclosure provides a liquid cartridge including: a liquid chamber configured to store liquid therein; a liquid outlet configured to allow liquid flow therethrough; a liquid channel; a first closing part; an air channel; a second closing part; and a third closing part. The liquid channel connects between the liquid chamber and the liquid outlet to allow the liquid to flow in a flowing direction from the liquid chamber toward the liquid outlet. The first closing part is configured to open and close the liquid outlet. The air channel extends from the liquid chamber to an outside of the liquid cartridge to provide communication between the liquid chamber and ambient air. The second closing part is configured to open and close the air channel. The third closing part is provided in the liquid channel and is configured to open and close the liquid channel, the third closing part having a first surface facing upstream in the flowing direction and a second surface opposite the first surface and facing downstream in the flowing direction, the third closing part being configured to deflect between a closed state and an open state based on a first pressure applied to the first surface and a second pressure applied to the second surface, a difference between the first pressure and the second pressure being defined by subtracting a value of the second pressure from a value of the first pressure, the third closing part deflecting into the closed state when the difference is equal to or greater than a predetermined threshold value, the third closing part deflecting into the open state when the difference is smaller than the predetermined threshold value. 
     According to still another aspect, there is also provided a liquid ejecting device including: a liquid cartridge; a cartridge receiving section configured to receive the liquid cartridge; a liquid ejecting head; a connecting member; and a purging mechanism. The liquid cartridge includes: a liquid chamber configured to store liquid therein; a liquid outlet configured to allow liquid flow therethrough; a liquid channel connecting between the liquid chamber and the liquid outlet to allow the liquid to flow in a flowing direction from the liquid chamber toward the liquid outlet; a first closing part configured to open and close the liquid outlet; an air channel extending from the liquid chamber to an outside of the liquid cartridge to provide communication between the liquid chamber and ambient air; a second closing part configured to open and close the air channel; and a third closing part provided in the liquid channel and configured to open and close the liquid channel, the third closing part having a first surface facing upstream in the flowing direction and a second surface opposite the first surface and facing downstream in the flowing direction, the third closing part being configured to deflect between a closed state and an open state based on a first pressure applied to the first surface and a second pressure applied to the second surface, a difference between the first pressure and the second pressure being defined by subtracting a value of the second pressure from a value of the first pressure, the third closing part deflecting into the closed state when the difference is equal to or greater than a predetermined threshold value, the third closing part deflecting into the open state when the difference is smaller than the predetermined threshold value. The connecting member connects the liquid ejecting head and the liquid outlet of the liquid cartridge received in the cartridge receiving section to provide communication between the liquid ejecting head and the liquid outlet. The purging mechanism is configured to draw liquid from the liquid ejecting head. The predetermined threshold value is larger than a value obtained by subtracting a value of the second pressure applied to the second surface when the purging mechanism draws the liquid from the liquid ejecting head from a value of the first pressure applied to the first surface when the air channel is opened. 
     According to still another aspect, there is also provided a method of manufacturing a liquid cartridge. The liquid cartridge includes: a liquid chamber configured to store liquid therein; a liquid outlet configured to allow liquid flow therethrough; a liquid channel connecting between the liquid chamber and the liquid outlet to allow the liquid to flow in a flowing direction from the liquid chamber toward the liquid outlet; a first closing part configured to open and close the liquid outlet; an air channel extending from the liquid chamber to an outside of the liquid cartridge to provide communication between the liquid chamber and ambient air; a second closing part configured to open and close the air channel; and a third closing part provided in the liquid channel and configured to open and close the liquid channel, the third closing part having a first surface facing upstream in the flowing direction and a second surface opposite the first surface and facing downstream in the flowing direction, the third closing part being configured to deflect between a closed state and an open state based on a first pressure applied to the first surface and a second pressure applied the second surface, a difference between the first pressure and the second pressure being defined by subtracting a value of the second pressure from a value of the first pressure, the third closing part deflecting into the closed state when the difference is equal to or greater than a predetermined threshold value, the third closing part deflecting into the open state when the difference is smaller than the predetermined threshold value. The method includes: decompressing the liquid chamber through the air channel; introducing liquid into the liquid chamber through the liquid channel after decompressing the liquid chamber; adjusting pressure within the liquid chamber to be greater than atmospheric pressure by at least the threshold value after introducing the liquid into the liquid chamber; and sealing the liquid chamber off from ambient air after adjusting the pressure within the liquid chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is a conceptual cross-sectional view showing an internal construction of a printer provided with a cartridge-receiving section  110  that can detachably receive an ink cartridge  30  according to a first embodiment of the present disclosure; 
         FIG. 2  is a diagram conceptually showing structures of a purging mechanism  120 , a recording head  21  and a carriage  22  according to the first embodiment; 
         FIG. 3  is a right side view showing an external appearance of the ink cartridge  30  according to the first embodiment; 
         FIG. 4  is an exploded perspective view showing a structure of the ink cartridge  30  according to the first embodiment without a cartridge cover  131 ; 
         FIG. 5A  is a perspective view showing a structure of a frame  31  of the ink cartridge  30  according to the first embodiment as viewed from its rear and right side; 
         FIG. 5B  is a perspective view showing the structure of the frame  31  of the ink cartridge  30  according to the first embodiment as viewed from its front and right side; 
         FIG. 6A  is a right side view of the frame  31  of the ink cartridge  30  according to the first embodiment; 
         FIG. 6B  is a left side view of the frame  31  of the ink cartridge  30  according to the first embodiment; 
         FIG. 7A  is an exploded perspective view of components required for opening and closing a valve chamber  47  of the ink cartridge  30  according to the first embodiment as viewed from diagonally rearward thereof; 
         FIG. 7B  is an exploded perspective view of the components required for opening and closing the valve chamber  47  of the ink cartridge  30  according to the first embodiment as viewed from diagonally frontward thereof; 
         FIG. 8A  is a perspective view showing an external appearance of a valve  77  the ink cartridge  30  according to the first embodiment as viewed from diagonally frontward thereof; 
         FIG. 8B  is a perspective view showing the external appearance of the valve  77  the ink cartridge  30  according to the first embodiment as viewed from diagonally rearward thereof; 
         FIG. 9A  is a right side view of the ink cartridge  30  according to the first embodiment received in the cartridge-receiving section  110 , wherein the cartridge cover  131  and films  37  and  38  are omitted; 
         FIG. 9B  is a cross-sectional view of the ink cartridge  30  according to the first embodiment received in the cartridge-receiving section  110  taken along a plane B-B shown in  FIG. 9A ; 
         FIG. 10  is a cross-sectional view of the ink cartridge  30  according to the first embodiment taken along a plane corresponding to the plane B-B shown in  FIG. 9A , wherein the valve  77  is in its first state; 
         FIG. 11  is a cross-sectional view of the ink cartridge  30  according to the first embodiment taken along a plane corresponding to the plane B-B shown in  FIG. 9A , wherein the valve  77  is in its intermediate state; 
         FIG. 12  is a cross-sectional view of the ink cartridge  30  according to the first embodiment taken along a plane corresponding to the plane B-B shown in  FIG. 9A  at a moment when the valve  77  has just arrived at its second state; 
         FIG. 13  is a cross-sectional view of the ink cartridge  30  according to the first embodiment taken along a plane corresponding to the plane B-B shown in  FIG. 9A  when a prescribed period of time has elapsed since the valve  77  reached the second state; 
         FIG. 14  is a flow chart illustrating a process for manufacturing the ink cartridge  30  according to the first embodiment; 
         FIG. 15  is a vertical cross-sectional view showing structures of a valve  277  and in the vicinity thereof in a configuration according to a second embodiment of the present disclosure; 
         FIG. 16  is a vertical cross-sectional view of an ink cartridge  330  according to a third embodiment of the present disclosure as viewed from its right side, wherein a valve body  397  is in a first state; and 
         FIG. 17  is a vertical cross-sectional view of the ink cartridge  330  according to the third embodiment of the present disclosure as viewed from its right side, wherein the valve body  397  is in a second state. 
     
    
    
     DETAILED DESCRIPTION 
     First, a first embodiment of the present disclosure will be described while referring to  FIGS. 1 through 13 . 
     In the following description, a mounting direction  51  is defined as a direction that an ink cartridge  30  is inserted into a cartridge-receiving section  110 , and a removing direction  52  is defined as a direction opposite the mounting direction  51 , that is, a direction in which the ink cartridge  30  is extracted from the cartridge-receiving section  110 . While the mounting and removing directions  51  and  52  are horizontal directions in the present disclosure, the mounting and removing directions  51  and  52  need not be horizontal directions. Further, a downward direction  53  is defined as the direction of gravitational force acting on the ink cartridge  30  and an upward direction  54  is defined as a direction opposite the gravitational direction when the ink cartridge  30  has been inserted into the cartridge-receiving section  110 , i.e., when the ink cartridge  30  is in an operational state. Further, a rightward direction  55  and a leftward direction  56  are defined based on a perspective of a user viewing the side of the ink cartridge  30  facing in the mounting direction  51 . The rightward and leftward directions  55  and  56  are opposite to each other and orthogonal to the mounting and removing directions  51  and  52  and the downward and upward directions  53  and  54 . 
     Unless otherwise stated, the following description will assume that the ink cartridge  30  is in its operational state. Here, the operational state of the ink cartridge  30  denotes an orientation of the ink cartridge  30  when mounted in the cartridge-receiving section  110  of a printer  10  and capable of being used thereby, for example. In other words, the mounting and removing directions  51  and  52  are horizontal when ink cartridge  30  is in the operational state. 
     1. First Embodiment 
     &lt;Overview of the Printer  10 &gt; 
       FIG. 1  shows the printer  10  (an example of a liquid ejecting device) configured to record images on recording sheets by selectively ejecting ink droplets onto the sheets based on an inkjet-recording method. The printer  10  includes the cartridge-receiving section  110  for receiving the ink cartridge  30  therein as an example of a cartridge receiving section. 
     The cartridge-receiving section  110  has one surface formed with an opening  112 . The ink cartridge  30  (as an example of a liquid cartridge) is inserted into the cartridge-receiving section  110  in the mounting direction  51  and extracted from the cartridge-receiving section  110  in the removing direction  52  through the opening  112 . The mounting direction  51  is an example of a first direction, and the removing direction  52  is an example of a second direction. 
     The ink cartridge  30  is configured to store ink (as an example of liquid) that the printer  10  can use for printing. It should be noted here that, in the printer  10  of the present embodiment, four kinds of ink cartridges  30  corresponding to four colors of cyan, magenta, yellow and black can be mounted in the cartridge-receiving section  110 . However, for an explanatory purpose, in the following description and accompanying drawings, only one ink cartridge  30  is assumed to be accommodated in the cartridge accommodating section  110 . 
     The printer  10  also includes a recording head  21  (as an example of a recording head), an ink tube  20  (as an example of a connecting member) connecting the recording head  21  to the cartridge-receiving section  110 , and a purging mechanism  120  as an example of a purging mechanism (see  FIG. 2 ). 
     The ink tube  20  provides communication between the recording head  21  and a through-hole  71  described later formed in the ink cartridge  30  when the ink cartridge  30  is in the operational state. 
     The recording head  21  is provided with a sub-tank  28 , and nozzles  29 . The sub-tank  28  temporarily holds ink to be supplied through the ink tube  20 . The recording head  21  selectively ejects ink supplied from the sub-tank  28  through the nozzles  29  according to the inkjet-recording method. More specifically, the recording head  21  is provided with a head control board  21 A, and piezoelectric elements  29 A corresponding one-on-one to the nozzles  29 . The head control board  21 A is configured to selectively apply drive voltages to the piezoelectric elements  29 A in order to eject ink selectively from the nozzles  29 . 
     The printer  10  also includes a sheet tray  15 , a feeding roller  23 , a conveying path  24 , a pair of conveying rollers  25 , a platen  26 , a pair of discharge rollers  27 , and a discharge tray  16 . In the printer  10 , the feeding roller  23  is configured to feed sheets of paper from the sheet tray  15  onto the conveying path  24 , and the conveying rollers  25  convey the sheets over the platen  26 . The recording head  21  is configured to selectively eject ink onto each sheet as the sheet passes over the platen  26 , whereby an image is recorded on each sheet. The discharge rollers  27  are configured to receive the sheet that has passed over the platen  26  and discharge the sheet onto the discharge tray  16  provided on a downstream end of the conveying path  24 . 
     In the first embodiment, the recording head  21  is mounted in a movable carriage  22  (see  FIG. 2 ). Through movements of the carriage  22 , the recording head  21  can be made movable between a printing position directly above the conveying path  24 , and a retracted position not directly above the conveying path  24 . The recording head  21  is moved to the printing position when ejecting ink onto the sheets and is moved to the retracted position in order for the purging mechanism  120  to draw ink out of the recording head  21 . 
     The purging mechanism  120  shown in  FIG. 2  is configured to use suction to extract ink from the nozzles  29  formed in the recording head  21 . The purging mechanism  120  is disposed directly beneath the recording head  21  when the recording head  21  is at the retracted position. 
     The purging mechanism  120  includes a cap  121  capable of covering the nozzles  29 , a cam mechanism  122  for moving the cap  121  up and down, a tube  123  through which ink can flow, a pump  124  for drawing ink, and a waste ink tank  125  for collecting the extracted ink. 
     Note that  FIG. 2  schematically depicts the purging mechanism  120  in order to illustrate how the tube  123  connects the cap  121  to the waste ink tank  125 . Hence, the positional relationships of components in  FIG. 2  do not necessarily represent the positional relationships of components in the first embodiment accurately. 
     The cap  121  is configured of a rubber material. The cap  121  can confront the recording head  21  from below when the recording head  21  is in its retracted position. The cam mechanism  122  is driven by a motor (not shown). When driven, the cam mechanism  122  moves the cap  121  up and down. When the cam mechanism  122  moves the cap  121  in the upward direction  54 , the cap  121  contacts a bottom surface of the recording head  21  and covers the nozzles  29 . When the cam mechanism  122  moves the cap  121  in the downward direction  53 , the cap  121  separates from the recording head  21 . 
     The cap  121  is connected to one end of the tube  123 . The tube  123  is a flexible tube formed of a resin material. The other end of the tube  123  is connected to the waste ink tank  125 . Thus, through the tube  123 , the cap  121  is in communication with the waste ink tank  125 . 
     In the first embodiment, the pump  124  is a rotary tube pump. The pump  124  has a pump casing provided with an inner wall surface, and revolving rollers that can move along the inner wall surface. The tube  123  is arranged between the inner wall surface and the rollers. The rollers are configured to be driven to revolve by a motor (not shown). When driven to revolve, the rollers squeeze the tube  123 , causing ink in the nozzles  29  to be drawn out into the tube  123 . The ink in the tube  123  is then forced to move from an upstream side (the cap  121  end) toward a downstream side (the waste ink tank  125  end). 
     [Cartridge-Receiving Section  110 ] 
     As shown in  FIG. 1 , the ink cartridge  30  can be mounted in the cartridge-receiving section  110 . When the ink cartridge  30  is in its operational state, ink stored in the ink cartridge  30  is transported to the ink tube  20  through the cartridge-receiving section  110  and through the ink tube  20  to the recording head  21 . 
     The cartridge-receiving section  110  also includes a case  101 , and an ink needle  102 . Note that  FIG. 1  shows a state where the ink cartridge  30  has been completely mounted in the cartridge-receiving section  110 , i.e., the ink cartridge  30  is in its operational state. As mentioned earlier, although not shown in the drawings, the cartridge-receiving section  110  can accommodate four of the ink cartridges  30  corresponding to the ink colors cyan, magenta, yellow, and black. 
     [Ink Needle  102 ] 
     As shown in  FIG. 1 , the opening  112  is formed in one end of the case  101  positioned furthest downstream in the removing direction  52 . The case  101  has an inner surface  111  positioned furthest downstream in the mounting direction  51 . This inner surface  111  facing the opening  112  in the mounting and removing directions  51  and  52  will be called an inner back surface  111  of the case  101 . The ink needle  102  protrudes in the removing direction  52  from the inner back surface  111  of the case  101 . The ink needle  102  is arranged at such a position on the inner back surface  111  that the ink needle  102  can confront a cylindrical wall  46  of the ink cartridge  30  described later. 
     As shown in  FIG. 11 , the ink needle  102  is a tube-like needle formed of a resin material. A liquid channel is formed longitudinally through a center portion of the ink needle  102 . The ink needle  102  has a distal end (downstream end in the removing direction  52 ) that has a circumferential wall in which a pair of communication holes  104  is formed. The ink needle  102  has a base end  103  (downstream end in the mounting direction  51 ) that is connected to the ink tube  20 , but the ink tube  20  has been omitted from  FIGS. 9B and 11-13 . The pair of the communication holes  104  is formed at opposing positions with respect to an axis of the ink needle  102 . The communication holes  104  provide fluid communication between the interior and exterior of the ink needle  102  so that ink can flow therethrough. 
     As shown in  FIG. 13 , when the ink needle  102  is inserted into the cylindrical wall  46  far enough for the communication holes  104  to be positioned inside the cylindrical wall  46 , ink in an ink chamber  36  (described later) can flow through a valve chamber  47  (described later) formed inside the cylindrical wall  46  and into the ink tube  20  connected to the ink needle  102 . Note that the definition of “needle” in this specification is a generic term that should include the meaning of a narrow tube-like member and need not be a member with a pointed tip at the downstream end in the removing direction  52 . 
     It should be noted there that the distal end of the ink needle  102  (downstream end in the removing direction  52 ) and the communication holes  104  should define a distance therebetween in the mounting and removing directions  51  and  52  that is shorter than a distance in the mounting and removing directions  51  and  52  between a sealing part  84  and an opening  64  described later when a valve  77  described later is in a first state (the state shown in  FIG. 10 ). Also, this distance between the distal end of the ink needle  102  (downstream end in the removing direction  52 ) and the communication holes  104  in the mounting and removing directions  51  and  52  is shorter than a distance in the mounting and removing directions  51  and  52  between a sealing part  85  and an opening  61  described later when the valve  77  is in the first state. In the first embodiment, this distance between the distal end of the ink needle  102  (downstream end in the removing direction  52 ) and the communication holes  104  in the mounting and removing directions  51  and  52  is substantially zero, since the communication holes  104  are formed in the very distal end of the ink needle  102 . 
     [Ink Cartridge  30 ] 
     As shown in  FIGS. 3 and 4 , the ink cartridge  30  includes a frame  31 , and a cartridge cover  131  that covers the frame  31 . Inside the frame  31  formed are the ink chamber  36  (an example of a liquid chamber), the valve chamber  47  (an example of a valve chamber), and a communication path  130  (an example of a communication path). The cartridge cover  131  shown in  FIG. 3  is configured of two members that can be fitted together. The two members constituting the cartridge cover  131  cover the frame  31  with the frame  31  sandwiched therebetween. Note that the cartridge cover  131  has been omitted from  FIGS. 1, 4-6, and 9A . As shown  FIG. 3 , the cartridge cover  131  has a front wall  132  in which an opening  133  is formed. A cap  72 , which is mounted on a tip end of the cylindrical wall  46  (see  FIG. 5 ) constituting part of the frame  31 , protrudes out through the opening  133 . 
     When the ink cartridge  30  has been mounted in the cartridge-receiving section  110 , ink stored in the ink chamber  36  can be supplied to the exterior of the ink cartridge  30  through the opening  133  and valve chamber  47 . The ink cartridge  30  is inserted into and extracted from the cartridge-receiving section  110  in an upright state shown in  FIG. 3 . 
     [Frame  31 ] 
     As shown in  FIG. 4 , the frame  31  has an external shape similar to a rectangular parallelepiped that appears flattened in the rightward and leftward directions  55  and  56 . Thus, the frame  31  has dimensions in the upward and downward directions  54  and  53  and the mounting and removing directions  51  and  52  that are greater than dimension of the frame  31  in the rightward and leftward directions  55  and  56 . The frame  31  is formed of a resin material and has been integrally molded. In other words, the frame  31  is a resin-molded product. 
     The frame  31  is configured of a front wall  40 , a rear wall  41 , a top wall  39  and a bottom wall  42 . The front wall  40  and rear wall  41  at least partially overlap each other when viewing the ink cartridge  30  in the mounting direction  51  or removing direction  52 . The top wall  39  and bottom wall  42  at least partially overlap each other when viewing the ink cartridge  30  in the upward direction  54  or downward direction  53 . 
     When the ink cartridge  30  is mounted in the cartridge-receiving section  110 , the front wall  40  is oriented frontward (downstream in the mounting direction  51 ) and the rear wall  41  is oriented rearward (upstream in the mounting direction  51 ). The top wall  39  connects top edges of the front wall  40  and rear wall  41 . The bottom wall  42  connects bottom edges of the front wall  40  and rear wall  41 . 
     The frame  31  is open on its right and left sides (the sides facing in the rightward and leftward directions  55  and  56 ). Films  37  and  38  provide a liquid-tight seal on the respective right and left sides of the frame  31 . The films  37  and  38  have been omitted from  FIGS. 5, 6, and 9 . The film  37  has an outer shape that substantially conforms to an outer shape of the frame  31  as viewed from the right. The film  37  is heat-sealed to right edges of the top wall  39 , front wall  40 , rear wall  41 , and bottom wall  42 . In this way, the film  37  constitutes a right wall of the ink chamber  36 . The film  37  is an example of a wall member. Similarly, an outer shape of the film  38  substantially conforms to the outer shape of the frame  31  when viewed from the left. The film  38  is heat-sealed to left edges of the top wall  39 , front wall  40 , rear wall  41 , and bottom wall  42 . In this way, the film  38  constitutes a left wall of the ink chamber  36 . Note that the films  37  and  38  may be affixed to the respective sides of the frame  31  through a method other than heat-sealing, such as high-frequency welding or bonding with adhesive. 
     The frame  31  also includes a plurality of inner walls including a top inner wall  114 , a front inner wall  115 , a rear inner wall  116 , and a bottom inner wall  117 . The top inner wall  114 , front inner wall  115 , rear inner wall  116 , and bottom inner wall  117  are formed at positions respectively inside of the top wall  39 , front wall  40 , rear wall  41 , and bottom wall  42  when the ink cartridge  30  is viewed in the rightward direction  55  or leftward direction  56 . 
     Right edges of the top inner wall  114 , front inner wall  115 , rear inner wall  116 , and bottom inner wall  117  are at the same position as the right edges of the top wall  39 , front wall  40 , rear wall  41 , and bottom wall  42  in the rightward and leftward directions  55  and  56 . Hence, the film  37  is heat-sealed to the right edges of the top inner wall  114 , front inner wall  115 , rear inner wall  116 , and bottom inner wall  117  when being heat-sealed to the right edges of the top wall  39 , front wall  40 , rear wall  41 , and bottom wall  42 . Similarly, left edges of the bottom portion of the rear inner wall  116  and the bottom inner wall  117  are at the same position as the left edges of the top wall  39 , front wall  40 , rear wall  41 , and bottom wall  42  in the rightward and leftward directions  55  and  56 . Hence, the film  38  is heat-sealed to the left edges of the bottom portion of the rear inner wall  116  and the bottom inner wall  117  when being heat-sealed to the left edges of the top wall  39 , front wall  40 , rear wall  41 , and bottom wall  42 . However, the film  38  is not affixed to left edges of the top inner wall  114 , front inner wall  115 , and upper portion of the rear inner wall  116 . 
     With this configuration, the ink chamber  36  in a right portion of the ink cartridge  30  is primarily formed by the top inner wall  114 , front inner wall  115 , rear inner wall  116 , bottom inner wall  117 , and film  37 , as shown in  FIG. 6A . However, the ink chamber  36  in a left portion of the ink cartridge  30  is primarily formed by the top wall  39 , front wall  40 , upper portion of the rear wall  41 , lower portion of the rear inner wall  116 , bottom inner wall  117 , and film  38 , as shown in  FIG. 6B . 
     Further, as shown in  FIGS. 5 and 6 , the frame  31  includes a plurality of additional inner walls including a first inner wall  141 , a second inner wall  142 , a third inner wall  143 , a fourth inner wall  144 , a fifth inner wall  145 , a sixth inner wall  146 , and a seventh inner wall  147 . 
     The first inner wall  141  extends in the mounting and removing directions  51  and  52  and the downward and upward directions  53  and  54 , and is connected to the left edges of the front inner wall  115  and rear inner wall  116 . The first inner wall  141  is connected to the front inner wall  115  and rear inner wall  116  in an area below the center of the ink chamber  36  in the upward and downward directions  54  and  53 . The first inner wall  141  is separated from the bottom inner wall  117 . That is, a gap is formed between the first inner wall  141  and bottom inner wall  117 . 
     The second inner wall  142  extends in the downward and upward directions  53  and  54  and the rightward and leftward directions  55  and  56 . The second inner wall  142  is positioned in an approximate center region of the ink chamber  36  in the mounting and removing directions  51  and  52 , and protrudes in the rightward direction  55  from the first inner wall  141 . 
     The third inner wall  143  extends in the downward and upward directions  53  and  54  and the rightward and leftward directions  55  and  56 . The third inner wall  143  is positioned between the second inner wall  142  and the front inner wall  115 , and protrudes in the rightward direction  55  from the first inner wall  141 . The third inner wall  143  at least partially overlaps the second inner wall  142  when viewed in the mounting and removing directions  51  and  52 . An opening  134  is formed in the third inner wall  143 . 
     The fourth inner wall  144  and fifth inner wall  145  extend in the mounting and removing directions  51  and  52  and the rightward and leftward directions  55  and  56 . The fourth inner wall  144  is connected to top edges of the second inner wall  142  and third inner wall  143 . The fifth inner wall  145  is connected to bottom edges of the second inner wall  142  and third inner wall  143 . Left edges of the fourth inner wall  144  and fifth inner wall  145  are connected to the first inner wall  141 . 
     The sixth inner wall  146  extends from the top edge of the second inner wall  142  to an approximate center region of the fifth inner wall  145  in the mounting and removing directions  51  and  52 . More specifically, the sixth inner wall  146  extends diagonally in the removing direction  52  and downward direction  53  from the top edge of the second inner wall  142 , bends and extends in the mounting direction  51 , bends and extends in the upward direction  54 , and is connected to the bottom of the fifth inner wall  145  in the approximate center region thereof. Note that a portion of the sixth inner wall  146  extends farther leftward than the first inner wall  141  and forms an annular shape in a left side view (see  FIG. 6B ). Further, a portion of the sixth inner wall  146  extends lower than the bottom inner wall  117 , dividing the bottom inner wall  117  in the mounting and removing directions  51  and  52 . 
     As shown in  FIG. 6 , the seventh inner wall  147  extends in the mounting and removing directions  51  and  52  and the downward and upward directions  53  and  54 . The seventh inner wall  147  has peripheral edges connected to the portion of the sixth inner wall  146  forming the annular shape. An opening  135  is formed in the seventh inner wall  147 . 
     As shown in  FIG. 5 , the right edges of the second inner wall  142  and sixth inner wall  146  are at the same position as the right edges of the top wall  39 , front wall  40 , rear wall  41 , and bottom wall  42  in the rightward and leftward directions  55  and  56 . Therefore, the film  37  is also heat-sealed to the right edges of the second inner wall  142  and sixth inner wall  146  when being heat-sealed to the right edges of the top wall  39 , front wall  40 , rear wall  41 , and bottom wall  42 . 
     The heat-sealing described above forms a second valve chamber  47 B, as a portion of the valve chamber  47 . The second valve chamber  47 B is defined by the first inner wall  141 , second inner wall  142 , third inner wall  143 , fourth inner wall  144 , fifth inner wall  145  (portions of the frame  31 ), and film  37  (a separate member from the frame  31 ). Specifically, the second valve chamber  47 B is defined by wall surfaces of the first through fifth inner walls  141 - 145 , and film  37 . The second inner wall  142  has a surface  142 A facing the second valve chamber  47 B (see  FIG. 5B ). This surface  142 A is an example of a base wall surface. 
     In other words, the frame  31  includes the wall surfaces of the first through fifth inner walls  141 - 145  defining the second valve chamber  47 B so as to form an aperture  66  in the second valve chamber  47 B that faces in the rightward direction  55  orthogonal to the mounting and removing directions  51  and  52 . That is the aperture  66  is open rightward. The rightward direction  55  is an example of a third direction. The aperture  66  is closed when the film  37  is heat-sealed to the right edges of the second through fifth inner walls  142 - 145 . Hence, the film  37  defines the second valve chamber  47 B with the aperture  66  in a closed state. 
     The wall surfaces of the first through fifth inner walls  141 - 145  and film  37  that face the second valve chamber  47 B are examples of wall surfaces. Of these wall surfaces defining the second valve chamber  47 , the wall surfaces of the first inner wall  141 , fourth inner wall  144 , fifth inner wall  145 , and film  37  that face the second valve chamber  47 B are examples of a peripheral wall surface and extend in the mounting direction  51  from the surface  142 A. Further, the wall surfaces of the first inner wall  141 , fourth inner wall  144 , fifth inner wall  145 , and film  37  that face the second valve chamber  47 B define a rectangular-shaped cross section taken along a plane orthogonal to the mounting direction  51 . Note that this rectangular shape is merely an example of an annular shape. That is, the annular shape of the disclosure is not limited to a rectangular shape, but may be circular or elliptical, for example. 
     Also through the heat-sealing described above, the communication path  130  is formed by the first inner wall  141 , second inner wall  142 , fifth inner wall  145 , sixth inner wall  146 , seventh inner wall  147 , film  37 , and film  38 , as illustrated in  FIGS. 5 and 6 . In other words, the communication path  130  is defined by wall surfaces of the first inner wall  141 , second inner wall  142 , fifth inner wall  145 , sixth inner wall  146 , seventh inner wall  147 , the film  37 , and the film  38 . 
     The ink chamber  36  is in communication with the second valve chamber  47 B through the communication path  130 . That is, the communication path  130  extends from the ink chamber  36  to the second valve chamber  47 B. 
     The communication path  130  communicates with the second valve chamber  47 B through an opening  136  (an example of a fourth opening, see  FIG. 5B ). The opening  136  is a notched part formed in the second inner wall  142  defining the second valve chamber  47 B, and is defined by the second inner wall  142 , fourth inner wall  144 , and film  37 . 
     Further, the communication path  130  is in communication with the lower portion of the ink chamber  36  through the opening  135  (see  FIG. 6 ) and an opening  137  (an example of a third opening, see  FIG. 6B ). The opening  135  is formed in the seventh inner wall  147 , as described earlier. The opening  137  is formed as a notch in the annular shaped portion of the sixth inner wall  146 , as illustrated in  FIG. 6B , and is defined by the sixth inner wall  146  and the film  38 . More specifically, the opening  137  is in communication with the lower portion of the ink chamber  36  defined by the bottom inner wall  117 . In other words, the opening  137  is formed in a portion of the sixth inner wall  146  defining the bottom region of the ink chamber  36 . 
     Note that the bottom portion of the ink chamber  36  is positioned lower than the valve chamber  47  when the ink cartridge  30  is in the operational state. Further, the communication path  130  may be in communication with a first valve chamber  47 A (described later) constituting part of the valve chamber  47 , rather than the second valve chamber  47 B. 
     As shown in  FIGS. 5 and 6 , the frame  31  includes the cylindrical wall  46 . The cylindrical wall  46  extends in the mounting direction  51  from the third inner wall  143  to a position outside of the ink cartridge  30 . The cylindrical wall  46  has a downstream end in the mounting direction  51  (tip end) that protrudes out of the front wall  40 , while a downstream end of the cylindrical wall  46  in the removing direction  52  (base end) is positioned between the front wall  40  and rear wall  41 . The downstream end of the cylindrical wall  46  in the mounting direction  51  is open. The downstream end of the cylindrical wall  46  in the removing direction  52  is also open, and this opening constitutes the opening  134  formed in the third inner wall  143 . 
     The cylindrical wall  46  has an inner circumferential surface that extends continuously in a cross section taken along a plane orthogonal to the mounting direction  51 . In other words, the inner circumferential surface of the cylindrical wall  46  has an annular-shaped cross section. Thus, the inner circumferential surface of the cylindrical wall  46  appears annular when viewed in the mounting direction  51 . The inner circumferential surface of the cylindrical wall  46  is an example of a peripheral wall surface. Note that this annular shape is not limited to a circular shape, but may be elliptical or rectangular, for example. In other words, while the inner circumferential surface of the cylindrical wall  46  has a circular annular shape when viewed in the mounting direction  51  in the first embodiment, the inner circumferential surface of the cylindrical wall  46  may have an annular shape that is not circular. 
     While the inner circumferential surface of the cylindrical wall  46  in the first embodiment is annular shaped when viewed in the mounting direction  51  at any cross section along its entire length from the downstream end in the mounting direction  51  to the downstream end in the removing direction  52 , the cylindrical wall  46  may be formed such that only a portion of its inner circumferential surface is annular shaped when viewed in the mounting direction  51 . However, the inner circumferential surface of the cylindrical wall  46  must be annular shaped when viewed in the mounting direction  51  at least in areas that contact sealing parts  84 ,  85 , and  87  described later. 
     As shown in  FIG. 9B , the cylindrical wall  46  has an internal space that serving as the first valve chamber  47 A. Hence, the first valve chamber  47 A is defined by the inner circumferential surface of the cylindrical wall  46 . As shown in  FIG. 10 , the first valve chamber  47 A has a downstream end in the mounting direction  51  that is in communication with the exterior of the ink cartridge  30  via through-holes  71  and  76  described later. The first valve chamber  47 A also has a downstream end in the removing direction  52  that is in communication with the second valve chamber  47 B through the opening  134  formed in the third inner wall  143 . Hence, the second valve chamber  47 B is positioned on the downstream side of the first valve chamber  47 A in the removing direction  52  and is in communication with the first valve chamber  47 A. 
     Together, the first valve chamber  47 A and second valve chamber  47 B constitute the valve chamber  47 . Thus, the wall surfaces defining the valve chamber  47  include at least the surface  142 A of the second inner wall  142  and the inner circumferential surface of the cylindrical wall  46 . 
     The second valve chamber  47 B has a dimension in a direction orthogonal to the mounting and removing directions  51  and  52  that is greater than an inner diameter of the cylindrical wall  46  (dimension of the first valve chamber  47 A in a direction orthogonal to the mounting and removing directions  51  and  52 ). This is due to the structure of the downstream end of the second valve chamber  47 B in the mounting direction  51 . 
     Specifically, the walls and the film  37  that define downstream end of the second valve chamber  47 B in the mounting direction  51  are configured as described below. 
     As illustrated in  FIG. 5A , a recessed part  67  is formed in a portion of the first inner wall  141  defining the downstream end of the second valve chamber  47 B in the mounting direction  51 . The recessed part  67  is recessed in the leftward direction  56 . The recessed part  67  extends from the top edge to the bottom edge of the second valve chamber  47 B. Additionally, a recessed part  68  is formed in a portion of the fifth inner wall  145  defining the downstream end of the second valve chamber  47 B in the mounting direction  51 . The recessed part  68  is recessed in the downward direction  53 . The recessed part  68  extends from the left edge to the right edge of the second valve chamber  47 B. The recessed part  68  has a left edge that is formed continuously with the bottom edge of the recessed part  67 . The surface of the fourth inner wall  144  facing the second valve chamber  47 B is positioned higher than the upper portion of the inner circumferential surface of the cylindrical wall  46 . The film  37  is positioned rightward of the right end of the inner circumferential surface of the cylindrical wall  46 . 
     A liquid channel and an air channel are formed in the frame  31 . 
     As shown in  FIG. 9 , the liquid channel extends from the ink chamber  36  to the through-hole  71  (described later). Ink primarily flows through the liquid channel. The liquid channel passes through the communication path  130  and valve chamber  47 . The liquid channel has one end in communication with the ink chamber  36  via the opening  137  (see  FIG. 6B ), and another end in communication with the exterior of the ink cartridge  30  through the through-hole  71 . 
     As shown in  FIG. 6 , the air channel extends from the ink chamber  36  to the exterior of the ink cartridge  30 . Air primarily flows through the air channel. The air channel passes through a first air channel  60  described later, the valve chamber  47  (the first valve chamber  47 A shown in  FIG. 9B  in the first embodiment), and a second air channel  63  described later. In other words, the air channel includes the first air channel  60  and second air channel  63 . One end of the air channel is in communication with the ink chamber  36  via an opening  65  described later, while the other end is in communication with the exterior of the ink cartridge  30  via an opening  62  described later (see  FIG. 5B ). 
     [Valve Chamber  47 ] 
     As described above, the valve chamber  47  is a space defined by wall surfaces of a plurality of inner walls in the frame  31  and the film  37 . As shown in  FIG. 1 , the valve chamber  47  is disposed in a lower-front portion of the ink cartridge  30 . 
     As shown in  FIG. 9 , the first air channel  60 , the second air channel  63 , and the communication path  130  are connected to the valve chamber  47 . A sealing member  70  and the cap  72  are mounted on the tip end of the cylindrical wall  46  (the downstream end of the cylindrical wall  46  in the mounting direction  51 ). The valve  77  and a coil spring  86  are accommodated inside the cylindrical wall  46 . 
     [First Air Channel  60 ] 
     As shown in  FIG. 6A , the first air channel  60  allows air to flow between the valve chamber  47  (the first valve chamber  47 A in the first embodiment) and the exterior of the ink cartridge  30 . Thus, the first air channel  60  allows the valve chamber  47  to communicate with the atmosphere. 
     As shown in  FIG. 6 , the first air channel  60  is configured of a groove  60 A, a buffer chamber  60 B, a groove  60 C, a groove  60 D, a groove  60 E, and a groove  60 F. As shown in  FIG. 6A , the groove  60 A, buffer chamber  60 B, groove  60 C, groove  60 E, and groove  60 F are all open on the side facing in the rightward direction  55 , but are sealed liquid-tight by the film  37 . The groove  60 D is open on the side facing in the leftward direction  56 , as shown in  FIG. 6B , but is sealed liquid tight by the film  38 . 
     As shown in  FIG. 6A , the groove  60 A extends in the removing direction  52  along the top surface of the bottom wall  42 . One end of the groove  60 A is in communication with the first valve chamber  47 A via the opening  61  formed in the inner circumferential surface of the cylindrical wall  46 , while the other end of the groove  60 A is in communication with the buffer chamber  60 B. The opening  61  is an example of a first opening. 
     The buffer chamber  60 B is a space that is wider than the grooves constituting the first air channel  60 . The buffer chamber  60 B stores ink flowing through the groove  60 A from the valve chamber  47 , thereby reducing the amount of ink that flows through the buffer chamber  60 B into the groove  60 C. One end of the buffer chamber  60 B is in communication with the groove  60 A, while the other end is in communication with the groove  60 C. 
     The grooves  60 C,  60 E, and  60 F extend in the mounting and removing directions  51  and  52  and are arranged adjacent to each other between the top inner wall  114  and the top wall  39 . 
     One end of the groove  60 C is in communication with the buffer chamber  60 B, while the other end is in communication with the groove  60 D (see  FIG. 6B ) through an opening  139 . As shown in  FIG. 6B , one end of the groove  60 D is in communication with the groove  60 C via the opening  139 , while the other end of the groove  60 D is in communication with the groove  60 E via an opening  138 . As shown in  FIG. 6A , one end of the groove  60 E is in communication with the groove  60 D via the opening  138 , while the other end is in communication with the groove  60 F. One end of the groove  60 F is in communication with the groove  60 E, while the other end is in communication with the exterior of the ink cartridge  30  via the opening  62  formed in the front wall  40  (see  FIG. 5B ). 
     The opening  138  is surrounded by an annular rib  200  protruding in the rightward direction  55 , as shown in  FIG. 6A . A semipermeable membrane (not shown) is affixed to a peripheral edge (right edge) of the annular rib  200 . The semipermeable membrane is a porous membrane having micropores that allow passage of air while preventing passage of ink. For example, the semipermeable membrane may be formed of a fluoropolymer, such as polytetrafluoroethylene, polychlorotrifluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, or tetrafluoroethylene-ethylene copolymer. 
     As shown in  FIG. 6A , a labyrinthine structure  69  is provided at a bordering region between the groove  60 E and groove  60 F. 
     [Second Air Channel  63 ] 
     As shown in  FIG. 6A , the second air channel  63  allows air to flow between the valve chamber  47  (the first valve chamber  47 A in the first embodiment) and the ink chamber  36 . The second air channel  63  extends in the upward direction  54  from the first valve chamber  47 A adjacent to the groove  60 E and then extends in the removing direction  52  adjacent to the groove  60 C. One end of the second air channel  63  is in communication with the first valve chamber  47 A (see  FIG. 9 ) through an opening  64  formed in the inner circumferential surface of the cylindrical wall  46 . The other end of the second air channel  63  is in communication with an upper portion of the ink chamber  36  through the opening  65 . The opening  64  is an example of a second opening. 
     The opening  64  is formed at a position offset from the opening  61  in the removing direction  52 . The opening  65  is formed at a position higher than a level of ink accommodated in the ink chamber  36  when the ink cartridge  30  in an unused state (the state of a new ink cartridge before any ink has been expended) is in its operational state. 
     [Sealing Member  70 ] 
     As shown in  FIG. 7 , the sealing member  70  mounted in the cylindrical wall  46  has a general disc shape. As shown in  FIG. 10 , the sealing member  70  has an outer diameter that is substantially equivalent to the inner diameter of the cylindrical wall  46 . The sealing member  70  is tightly fitted into the tip end of the cylindrical wall  46 , forming a liquid-tight seal. The sealing member  70  is formed of a rubber or other elastic material, for example. 
     As shown in  FIGS. 7 and 10 , the through-hole  71  is formed in the sealing member  70  and penetrates a center region of the sealing member  70  in its thickness dimension (in the mounting and removing directions  51  and  52 ). The through-hole  71  provides communication between the first valve chamber  47 A and the exterior of the ink cartridge  30  and allows ink stored in the ink chamber  36  to flow. 
     The sealing member  70  has an inner circumferential surface  70 A (see  FIG. 10 , as an example of a peripheral surface) that defines the through-hole  71 . An annular rib  70 B is formed on the inner circumferential surface  70 A. The outer diameter of the ink needle  102  is slightly larger than an inner diameter of the annular rib  70 B and slightly smaller than an inner diameter of the through-hole  71 . Accordingly, when the ink needle  102  is inserted into the through-hole  71  as will be described later, the outer circumferential surface of the ink needle  102  forms a liquid-tight seal with the annular rib  70 B. 
     [Cap  72 ] 
     As shown in  FIG. 7 , the cap  72  mounted on the cylindrical wall  46  is configured of a disc-shaped cover part  73 , a cylindrical part  74 , and engaging parts  75 . The cylindrical part  74  protrudes from a side surface of the cover part  73  facing in the removing direction  52 . The engaging parts  75  protrude in the removing direction  52  from a protruding end of the cylindrical part  74 . As shown in  FIG. 7B , a through-hole  76  is formed in the cover part  73  and penetrates a center region of the cover part  73  in its thickness dimension (in the mounting and removing directions  51  and  52 ). The through-hole  76  has a diameter larger than that of the through-hole  71 . The cylindrical part  74  is provided to surround the through-hole  76 . The cap  72  is formed of a resin material, for example. 
     The cover part  73  contacts the sealing member  70  on the side of the sealing member  70  opposite the cylindrical wall  46 . Hence, the sealing member  70  is interposed between the cover part  73  and the tip end of the cylindrical wall  46  in the mounting and removing directions  51  and  52 . As shown in  FIG. 10 , the cylindrical part  74  covers the outer circumferential surface of the sealing member  70  and a portion on the outer circumferential surface of the cylindrical wall  46 . The engaging parts  75  engage with engagement parts  40 A provided on the front wall  40  (see  FIG. 9A ). The cap  72  holds the sealing member  70  on the tip end of the cylindrical wall  46 . 
     [Valve  77 ] 
     As shown in  FIGS. 9 and 10 , the valve  77  is disposed in the valve chamber  47 . In the first embodiment, a majority of the valve  77  is disposed in the first valve chamber  47 A, while only a portion of the valve  77  (downstream end thereof in the removing direction  52 ) is disposed in the second valve chamber  47 B. The valve  77  is capable of moving in the valve chamber  47  in the mounting and removing directions  51  and  52 . 
     As shown in  FIGS. 7 and 8 , the valve  77  includes a retaining part  79 , and a cylindrical elastic member  82 . A through-hole  81  is formed in the elastic member  82  and penetrates the elastic member  82  in the mounting and removing directions  51  and  52 . Part of the retaining part  79  (a body portion  150  described later) is inserted into the through-hole  81 . The retaining part  79  is formed of a resin material, for example. The elastic member  82  is formed of an elastic material such as rubber that has a lower rigidity than the retaining part  79 . 
     The retaining part  79  includes the body portion  150 , a columnar portion  151  (an example of a closing part; and a first closing part), and anchoring parts  153 . The body portion  150  has a general rod-like shape that extends in the mounting and removing directions  51  and  52 . The columnar portion  151  is provided on an end  150 A of the body portion  150  positioned downstream in the mounting direction  51  (see  FIG. 10 ). The anchoring parts  153  are provided on a downstream end of the body portion  150  in the removing direction  52 . 
     As shown in  FIGS. 7 and 8 , the elastic member  82  is configured of an end wall  154  (an example of a third closing part, and an example of an end wall), a cylindrical wall  155  that extends in the removing direction  52  from the end wall  154 , an air channel closing part  157  (as an example of a second closing part) having two sealing parts  84  and  85 , and a sealing part  87 . The end wall  154 , cylindrical wall  155 , air channel closing part  157 , and sealing part  87  are configured as a single integral unit. 
     As shown in  FIG. 10 , the end wall  154  constitutes a downstream end of the elastic member  82  in the mounting direction  51 . The end wall  154  is formed with an opening  81 A to penetrate a center portion of the end wall  154  in the mounting direction  51 . The cylindrical wall  155  defines the through-hole  81  therein. That is, the opening  81 A constitutes a downstream end of the through-hole  81  in the mounting direction  51 . The cylindrical wall  155  has a downstream end in the removing direction  52  in which an opening  81 B is formed. That is, the opening  81 B constitutes a downstream end of the through-hole  81  in the removing direction  52 . 
     As shown in  FIGS. 7 and 8 , the sealing parts  84 ,  85 , and  87  are flanges that protrude radially outward from an outer circumferential surface of the cylindrical wall  155 . The sealing parts  84 ,  85 , and  87  are examples of a first sealing part, a second sealing part and a third sealing part, respectively. Details of the sealing parts  84 ,  85  and  87  will be described later. 
     Now, the retaining part  79  and the elastic member  82  will be described more in detail. 
     As shown in  FIG. 10 , the body portion  150  of the retaining part  79  is inserted into the through-hole  81  of the elastic member  82 . The body portion  150  has a diameter smaller than an inner diameter of the through-hole  81 . Consequently, gaps are formed between the body portion  150  and an inner circumferential surface defining the through-hole  81  formed in the cylindrical wall  155  of the elastic member  82 . These gaps allow the flow of ink stored in the ink chamber  36 . That is, when passing through the valve chamber  47 , the liquid channel passes the gaps formed between the elastic member  82  and retaining part  79  within the through-hole  81 . In other words, the liquid channel extends from the ink chamber  36  to the through-hole  71  via the through-hole  81 . 
     The end  150 A of the body portion  150  has a smaller diameter than a diameter of a remaining portion of the body portion  150 . The end  150 A of the body portion  150  is inserted into the opening  81 A formed in the end wall  154  of the elastic member  82 . Note that the diameter of the end  150 A of the body portion  150  is smaller than an inner diameter of the opening  81 A. 
     As shown in  FIGS. 8A and 10 , when the body portion  150  has been inserted into the through-hole  81  of the elastic member  82 , the columnar portion  151  is positioned downstream of the elastic member  82  in the mounting direction  51 . Or, the columnar portion  151  protrudes out from the elastic member  82  in the mounting direction  51 . Specifically, the columnar portion  151  includes a disc part  151 A, contact parts  151 B (see  FIG. 10 ), and a protruding part  151 C (an example of a liquid-outlet sealing part). 
     As shown in  FIG. 10 , the disc part  151 A is disk-like shaped and has a surface  151 D facing the body portion  150 . This surface  151 D is an example of a third surface. The contact parts  151 B are formed on the surface  151 D of the disc part  151 A. More specifically, a plurality of the contact parts  151 B (four in the first embodiment) is provided on the surface  151 D of the disc part  151 A at intervals in a circumferential direction of the disc part  151 A. The contact parts  151 B are connected to the end  150 A of the body portion  150 , as shown in  FIG. 7A . As shown in  FIG. 10 , the contact parts  151 B contact a peripheral region defining the opening  81 A on the end wall  154  of the elastic member  82 . 
     As shown in  FIGS. 8A and 10 , the protruding part  151 C protrudes in the mounting direction  51  from another surface of the disc part  151 A opposite the surface  151 D in the mounting direction  51 . The protruding part  151 C is columnar-shaped and can be inserted into the through-hole  71  formed in the sealing member  70 . The protruding part  151 C has a diameter greater than the inner diameter of the through-hole  71 . Accordingly, as the protruding part  151 C is inserted into the through-hole  71 , the protruding part  151 C contacts the inner circumferential surface  70 A of the sealing member  70  defining the through-hole  71  and causes the inner circumferential surface  70 A to elastically deform. As a result, the protruding part  151 C can provide a liquid-tight seal in the through-hole  71 . As the valve  77  moves, the protruding part  151 C slides while being in close contact with the inner circumferential surface  70 A of the sealing member  70 . When the valve  77  is moved in the removing direction  52  from its position shown in  FIG. 10 , the protruding part  151 C separates from the sealing member  70  (see  FIG. 13 ), thereby opening the through-hole  71 . In this way, the protruding part  151 C can open and close the through-hole  71 . 
     As shown in  FIGS. 8B and 10 , the anchoring parts  153  are positioned downstream of the elastic member  82  in the removing direction  52  when the body portion  150  has been inserted into the elastic member  82 . As shown in  FIGS. 7 and 8B , a plurality of anchoring parts  153  (three in the first embodiment) is arranged at intervals in the circumferential direction of the body portion  150 . The anchoring parts  153  protrude from the body portion  150  in directions orthogonal to the removing direction  52 . As shown in  FIG. 10 , the anchoring parts  153  contact a peripheral region defining the opening  81 B constituting the downstream end of the through-hole  81  in the removing direction  52  formed in the elastic member  82 . 
     As described above, when the body portion  150  has been inserted into the elastic member  82 , the contact parts  151 B are in contact with the elastic member  82  around the periphery of the opening  81 A, and the anchoring parts  153  are in contact with the elastic member  82  around the periphery of the opening  81 B. Accordingly, the elastic member  82  can move within the valve chamber  47  in the mounting and removing directions  51  and  52  together with the retaining part  79 . 
     Referring to the elastic member  82 , as shown in  FIGS. 7 and 8 , the sealing parts  84 ,  85  and  87  are flanges provided on the cylindrical wall  155  of the elastic member  82 . The sealing parts  84 ,  85  and  87  are annular shaped when viewed in the mounting direction  51 . In the first embodiment, the sealing parts  84 ,  85  and  87  have a circular annular shape corresponding to the inner circumferential surface of the cylindrical wall  46 , but these components may have a non-circular annular shape corresponding to the inner circumferential surface of the cylindrical wall  46  when the inner circumferential surface of the cylindrical wall  46  has an annular cross-section that is not circular. 
     The sealing parts  84 ,  85 , and  87  are separated from each other in the mounting and removing directions  51  and  52 . The sealing part  85  is disposed offset from the sealing part  84  in the mounting direction  51 , and the sealing part  87  is provided offset in the removing direction  52  from the sealing part  84 . 
     As shown in  FIG. 10 , the sealing parts  84 ,  85 , and  87  form a liquid-tight and airtight seal with the inner circumferential surface of the cylindrical wall  46 . Outer diameters of the sealing parts  84 ,  85 , and  87  are greater than the inner diameter of the cylindrical wall  46  when the valve  77  is not inserted into the first valve chamber  47 A (in the state shown in  FIGS. 7 and 8 ). Accordingly, when the valve  77  is inserted into the first valve chamber  47 A (the state shown in  FIG. 10 ), the sealing parts  84 ,  85 , and  87  elastically deform in such a direction that their outer diameters are reduced while remaining in close contact with the inner circumferential surface of the cylindrical wall  46 . 
     As shown in  FIG. 10 , the close contact formed by the sealing parts  84 ,  85 , and  87  with the inner circumferential surface of the cylindrical wall  46  isolates a first space  148  that includes the downstream end of the first valve chamber  47 A in the removing direction  52  from a second space  149  that includes the downstream end of the first valve chamber  47 A in the mounting direction  51  in an area formed between the outer circumferential surface of the elastic member  82  and the inner circumferential surface of the cylindrical wall  46 . 
     On the other hand, the first space  148  and second space  149  are sections of the liquid channel, and ink can flow between the first and second spaces  148  and  149  via the through-hole  81 . More specifically, when supplying ink from the ink chamber  36  to the outside of the ink cartridge  30 , the ink can flow in a direction from the first space  148  to the second space  149 , as shown in  FIG. 13 . This direction (an example of a flowing direction) is defined as an ink-supplying direction in which the ink can flow sequentially through: the spaces between the neighboring anchoring parts  153  juxtaposed in the circumferential direction of the body portion  150 ; the opening  81 B formed in the cylindrical wall  155 ; the space formed in the through-hole  81  between the outer circumferential surface of the body portion  150  and the inner circumferential surface of the cylindrical wall  155 ; the opening  81 A formed in the cylindrical wall  155 ; the spaces between the neighboring two contact parts  151 B juxtaposed in the circumferential direction of the body portion  150 ; and the space between the end wall  154  and columnar portion  151 . The ink-supplying direction at the opening  81 A formed in the end wall  154  is coincident with the mounting direction  51 . 
     As will be described later in greater detail, due to the close contact by the sealing parts  84 ,  85 , and  87  with the inner circumferential surface of the cylindrical wall  46 , the space between the sealing parts  84  and  85  can be a closed space so that air can flow therethrough. 
     When the valve  77  is in the position shown in  FIG. 10 , the sealing part  84  is positioned between the openings  61  and  64 . Thus, the sealing part  84  blocks the space between the first air channel  60  and second air channel  63 . The sealing parts  84 ,  85 , and  87  can slide while remaining in contact with the inner circumferential surface of the cylindrical wall  46  as the valve  77  moves. When the valve  77  is moved in the removing direction  52  from its position shown in  FIG. 10 , the openings  61  and  64  become positioned between the sealing parts  84  and  85 , as shown in  FIG. 13 . Consequently, the first and second air channels  60  and  63  can communicate with each other through the space between the sealing parts  84  and  85 . Thus, the ink chamber  36  can communicate with the exterior of the ink cartridge  30 , opening up the ink chamber  36  to the atmosphere. In other words, the air channel closing part  157  opens the air channel when the valve  77  is moved. With this configuration, the air channel closing part  157  can open and close the air channel. 
     The end wall  154  shown in  FIGS. 7B and 8A  is a flexible membranous member. As shown in  FIG. 10 , the end wall  154  has a first surface  158  facing in the removing direction  52 , a second surface  159  facing in the mounting direction  51  on the opposite side from the first surface  158 , and an annular rib  156  (see  FIG. 7B ) formed on the second surface  159 . The first surface  158  and second surface  159  are examples of a first surface and a second surface, respectively. 
     The first surface  158  partially defines the space in the through-hole  81  between the body portion  150  and the inner circumferential surface of the cylindrical wall  155 . The second surface  159  partially defines the space between the end wall  154  and the columnar portion  151 . Here, the space in the through-hole  81  between the body portion  150  and the inner circumferential surface of the cylindrical wall  155  is positioned upstream of the space between the end wall  154  and columnar portion  151  in the ink-supplying direction. 
     As described above, the end wall  154  is provided in the liquid channel. Further, the first surface  158  of the end wall  154  faces upstream in the ink-supplying direction, which is the direction from the ink chamber  36  toward the through-hole  71 . Further, the second surface  159  faces downstream in the ink-supplying direction. 
     The second surface  159  confronts the surface  151 D of the columnar portion  151  constituting the retaining part  79 . 
     As shown in  FIG. 7B , the annular rib  156  protrudes in the mounting direction  51  from the second surface  159  around the circumference of the opening  81 A. Further, the annular rib  156  is positioned outward of the contact parts  151 B in a radial direction of the disc part  151 A. As shown in  FIGS. 10 and 13 , the annular rib  156  can be made to contact and separate from the surface  151 D of the disc part  151 A through deflection (or deformation) of the end wall  154 . As shown in  FIG. 10 , when the annular rib  156  contacts the surface  151 D of the disc part  151 A through deflection of the end wall  154 , the annular rib  156  blocks the space between the end wall  154  and columnar portion  151 , thereby closing the liquid channel. At this time, the end wall  154  is in the closed state. On the other hand, when deflection of the end wall  154  is relaxed, separating the annular rib  156  from the surface  151 D of the disc part  151 A, the space between the end wall  154  and columnar portion  151  is open, thereby opening the liquid channel. At this time, the end wall  154  is in its open state. In this way, the end wall  154  can open and close the liquid channel. 
     Note that the annular rib  156  need not be formed on the second surface  159 . In this case, the second surface  159  may contact and separate from the surface  151 D of the disc part  151 A through deflection of the end wall  154 . 
     The end wall  154  can be switched between its closed state shown in  FIG. 10  and its open state shown in  FIG. 13  by applying pressures to the first surface  158  and second surface  159 , respectively. The pressure applied to the first surface  158  is pressure applied in the mounting direction  51  from the space constituting the through-hole  81  toward the first surface  158 . The pressure applied to the second surface  159  is pressure applied in the removing direction  52  from the space between the end wall  154  and columnar portion  151  toward the second surface  159 . 
     In order for the end wall  154  to deflect into the closed state shown in  FIG. 10  so that the annular rib  156  contacts the surface  151 D of the disc part  151 A, a difference found by subtracting a value of the pressure applied to the second surface  159  from a value of the pressure applied to the first surface  158  must be equal to or larger than a threshold value, as will be described below. In order for the end wall  154  to return to the open state shown in  FIG. 13  so that the annular rib  156  separates from the surface  151 D of the disc part  151 A, the difference found by subtracting the value of the pressure applied to the second surface  159  from the value of the pressure applied to the first surface  158  must be smaller than the threshold value. 
     The threshold value is determined based on a thickness of the end wall  154 , surface areas of the first surface  158  and second surface  159 , and properties and the like of the material forming the end wall  154 . In the first embodiment, the threshold value is set larger than a difference found by subtracting a value of the pressure applied to the second surface  159  when the purging mechanism  120  draws ink from the nozzles  29  of the recording head  21  from a value of the pressure applied to the first surface  158  when the ink cartridge  30  is mounted in the cartridge-receiving section  110  and the air channel is open. 
     Here, the pressure applied to the first surface  158  when the air channel is in its open state is the pressure applied toward the first surface  158  in the mounting direction  51 , and has a magnitude equivalent to normal atmospheric pressure. The pressure applied to the second surface  159  is pressure applied in the removing direction  52  toward the second surface  159  when the revolving rollers of the pump  124  are driven while the ink cartridge  30  is mounted in the cartridge-receiving section  110  and the cap  121  covers the nozzles  29 . For example, if atmospheric pressure is X kilopascals (kPa) and the pressure applied to the second surface  159  during a purging operation is (X-Y) kPa, the threshold value is set to a value greater than Y kPa. For example, if atmospheric pressure is 100 kPa and the pressure applied to the second surface  159  during a purging operation is (100−2) kPa, i.e., 98 kPa, the threshold value is set to a value greater than 2 kPa, such as 10 kPa. 
     [Coil Spring  86 ] 
     As shown in  FIGS. 9 and 10 , the coil spring  86  (an example of a biasing member) is disposed between the surface  142 A of the second inner wall  142  (see  FIG. 5B ) and the valve  77 . Specifically, the coil spring  86  has one end that contacts the surface  142 A, and another end that contacts the anchoring parts  153  of the retaining part  79  constituting the valve  77 . The coil spring  86  urges the valve  77  in the mounting direction  51 , thereby maintaining the valve  77  in its first state in the valve chamber  47  (see  FIG. 10 ) for contacting the sealing member  70 . Note that a plate spring or other urging member may be used in place of the coil spring  86 . 
     &lt;Operations for Mounting the Ink Cartridge  30  in the Cartridge-Receiving Section  110 &gt; 
     Next, the movement of the valve  77  during a process of mounting the ink cartridge  30  in the cartridge-receiving section  110  will be described with reference to  FIGS. 10 through 13 . 
     Prior to the ink cartridge  30  being mounted in the cartridge-receiving section  110 , the valve  77  is in the first state shown in  FIG. 10 . In the first state, the valve  77  is made to contact the sealing member  70  by the urging force of the coil spring  86 . More specifically, when the valve  77  is in the first state, the protruding part  151 C of the retaining part  79  has advanced into the through-hole  71  formed in the sealing member  70  and forms a liquid-tight seal with the inner circumferential surface  70 A of the sealing member  70 , thereby closing the through-hole  71 . Thus, the liquid channel is sealed off from the outside of the ink cartridge  30  at the through-hole  71 . 
     At this time, the sealing part  84  is positioned between the openings  61  and  64  and is in close contact with the inner circumferential surface of the cylindrical wall  46 . Accordingly, the sealing part  84  interrupts the communication of air between the openings  61  and  64 , thereby interrupting the communication of air between the first air channel  60  and second air channel  63 . Consequently, the ink chamber  36  is not in communication with the atmosphere. Note that the sealing part  84  may be arranged to partially overlap the openings  61  and  64 , provided that communication of air is interrupted between the first and second air channels  60  and  63 . 
     At the same time, the sealing part  85  is positioned downstream of the opening  61  in the mounting direction  51  and is in close contact with the inner circumferential surface of the cylindrical wall  46 , thereby interrupting the communication of air and ink between the first air channel  60  and through-hole  71 . Note that the sealing part  85  may also partially overlap the opening  61 , provided that communication of air and ink is interrupted between the first air channel  60  and through-hole  71 . 
     At the same time, the sealing part  87  is positioned downstream of the opening  64  in the removing direction  52  and contacts and forms a liquid-tight seal with the inner circumferential surface of the cylindrical wall  46 , thereby interrupting the communication of air and ink between the second air channel  63  and second valve chamber  47 B. Note that the sealing part  87  may also partially overlap the opening  64 , provided that communication of air and ink is interrupted between the second air channel  63  and second valve chamber  47 B. 
     When the valve  77  is in the first state, as described above, the ink chamber  36  is not in communication with the atmosphere. Therefore, the internal pressure of the ink chamber  36  is not necessarily at atmospheric pressure. In the first embodiment, when the valve  77  is in the first state, the internal pressure of the ink chamber  36  is higher than atmospheric pressure. Specifically, the internal pressure of the ink chamber  36  is greater than atmospheric pressure by at least the threshold value described above. 
     Since the internal pressure of the ink chamber  36  is greater than atmospheric pressure by at least the threshold value, the value obtained by subtracting the value of the pressure applied to the second surface  159  of the end wall  154  constituting the elastic member  82  from the value of the pressure applied to the first surface  158  of the end wall  154  is equal to or greater than the threshold value. Accordingly, the end wall  154  is in its closed state, i.e., is deflected such that the annular rib  156  contacts the surface  151 D of the disc part  151 A to close the liquid channel. Thus, the liquid channel is sealed off from the outside of the ink cartridge  30  at a position between the end wall  154  and columnar portion  151  in addition to the position of the through-hole  71  (due to contact between the protruding part  151 C and the inner circumferential surface  70 A constituting the through-hole  71 ). 
       FIG. 11  shows the internal state of the valve chamber  47  as the ink cartridge  30  is being mounted in the cartridge-receiving section  110  (when the ink needle  102  has been partially inserted into the through-hole  71  of the sealing member  70 ). As the ink cartridge  30  is being mounted in the cartridge-receiving section  110 , the valve  77  is in an intermediate state at which the valve  77  has moved in the removing direction  52  from the first state against the urging force of the coil spring  86  due to pressure from the ink needle  102  inserted into the valve chamber  47  through the through-holes  76  and  71 . 
     When the valve  77  is in this intermediate state, a portion of the protruding part  151 C remains inserted in the through-hole  71  of the sealing member  70 . That is, the protruding part  151 C still forms a liquid-tight seal with the inner circumferential surface  70 A of the sealing member  70 . Accordingly, the protruding part  151 C interrupts communication between the first valve chamber  47 A and the through-holes  104  formed in the downstream end of the ink needle  102  in the removing direction  52 . Thus, the liquid channel remains sealed off from the outside of the ink cartridge  30  at the through-hole  71 . 
     In this state, the sealing part  84  is positioned between an edge of the opening  64  positioned downstream in the mounting direction  51  and another edge of the opening  64  positioned downstream in the removing direction  52 . Accordingly, air can flow between the openings  61  and  64 , and thus the first air channel  60  is in communication with the second air channel  63 . Consequently, the ink chamber  36  is in communication with the atmosphere through the first air channel  60 , the space between the sealing parts  84  and  85  (the first valve chamber  47 A), and the second air channel  63 . Thus, the air channel is open. 
     The sealing part  85  contacts the inner circumferential surface of the cylindrical wall  46  at a position downstream of the opening  61  in the mounting direction  51 . Accordingly, the sealing part  85  interrupts communication of air and ink between the first and second air channels  60  and  63  and the through-hole  71 . 
     The sealing part  87  contacts and forms a liquid-tight seal with the inner circumferential surface of the cylindrical wall  46  at a position downstream of the opening  64  in the removing direction  52 . Accordingly, the sealing part  87  interrupts the communication of air and ink between the second air channel  63  and second valve chamber  47 B. 
     When the valve  77  is in the intermediate state described above, the ink chamber  36  is in communication with the atmosphere. Accordingly, the internal pressure of the ink chamber  36  becomes atmospheric pressure after the valve  77  has been in the intermediate state for a prescribed time. 
     However, in the first embodiment it is assumed that the valve  77  moves from the first state to a second state described later after quickly passing through the intermediate state. Therefore, the valve  77  moves in the removing direction  52  from the intermediate state before the prescribed time elapses after arriving at the intermediate state. Accordingly, the internal pressure in the ink chamber  36  remains higher than atmospheric pressure while the valve  77  is in the intermediate state, just as when the valve  77  was in the first state. Accordingly, the end wall  154  is maintained in its closed state when the valve  77  is in the intermediate state. Hence, the liquid channel is sealed off from the outside of the ink cartridge  30  at the position between the end wall  154  and columnar portion  151  in addition to the position of the through-hole  71 . 
       FIG. 12  shows the internal state of the valve chamber  47  at the instant the ink cartridge  30  becomes completely mounted in the cartridge-receiving section  110  (the state in which ink can flow out of the ink cartridge  30 ). When the ink cartridge  30  is completely mounted in the cartridge-receiving section  110 , the valve  77  is in the second state in which the valve  77  has been moved in the removing direction  52  from the intermediate state against the urging force of the coil spring  86  due to the pressure applied by the ink needle  102  being further advanced into the valve chamber  47 . 
     When the valve  77  is in the second state, the protruding part  151 C has separated from the inner circumferential surface  70 A defining the through-hole  71  in the sealing member  70 . In other words, the retaining part  79  has been completely extracted from the through-hole  71  formed in the sealing member  70 . 
     In this state, the ink needle  102  has been further inserted into the through-hole  71  of the sealing member  70  so that the communication holes  104  formed in the ink needle  102  have advanced past the through-hole  71  into the first valve chamber  47 A. Consequently, the second space  149  of the first valve chamber  47 A is in communication with the outside of the ink cartridge  30  through the communication holes  104  and the liquid channel formed inside the ink needle  102 . However, since the end wall  154  is maintained in the closed state at the moment shown in  FIG. 12 , as will be described later, ink in the ink chamber  36  cannot flow outside the ink cartridge  30  through the communication holes  104  and the liquid channel formed inside the ink needle  102 . 
     At this time, the sealing part  84  is in contact with the inner circumferential surface of the cylindrical wall  46  at a position downstream of the opening  64  in the removing direction  52 . Accordingly, the sealing part  84  allows communication between the first and second air channels  60  and  63 , as when the valve  77  is in the intermediate state, and thus the air channel is open. 
     At the same time, the sealing part  85  contacts the inner circumferential surface of the cylindrical wall  46  at a position downstream of the opening  61  in the mounting direction  51 . Accordingly, the sealing part  85  interrupts communication of air and ink between the first and second air channels  60  and  63  and the through-hole  71 . 
     In addition, the sealing part  87  has advanced through the first valve chamber  47 A into the second valve chamber  47 B. In other words, the sealing part  87  is positioned downstream of the cylindrical wall  46  in the removing direction  52  and, hence, is separated from the cylindrical wall  46 . At this time, the sealing part  87  is at the same position in the mounting and removing directions  51  and  52  as the recessed parts  67  and  68  (see  FIG. 5 ), and is therefore separated from the first inner wall  141  and fifth inner wall  145 . Further, the sealing part  87  is positioned lower than the fourth inner wall  144  and separated from the same. The sealing part  87  is also positioned leftward from the film  37  and is separated from the same. With this arrangement, the sealing part  87  is not in contact with any wall surface as the valve  77  moves from the intermediate state toward the second state. In other words, by disposing the sealing part  87  at the same position as the recessed parts  67  and  68  in the mounting and removing directions  51  and  52  while the valve  77  is moved in the removing direction  52  from the first state, the sealing part  87  is separated from the wall surfaces defining the valve chamber  47 . Thus, the number of sealing parts contacting the wall surfaces defining the valve chamber  47  is reduced from three (the sealing parts  84 ,  85 , and  87 ) to two (the sealing parts  84  and  85 ), thereby reducing frictional resistance generated between the valve  77  and the wall surfaces. 
     In the first embodiment described above, the valve  77  is assumed to move quickly from the first state to the second state via the intermediate state. Therefore, at the instant the valve  77  arrives in the second state (the state shown in  FIG. 12 ), the internal pressure of the ink chamber  36  remains higher than atmospheric pressure, as when the valve  77  was in the first state and the intermediate state. Therefore, the end wall  154  remains in its closed state at the moment the valve  77  reaches the second state. Accordingly, while the liquid channel is open at the through-hole  71 , the liquid channel is sealed off from the outside of the ink cartridge  30  at the position between the end wall  154  and columnar portion  151 . 
       FIG. 13  shows the internal state of the valve chamber  47  once the prescribed time has elapsed after the ink cartridge  30  has been completely mounted in the cartridge-receiving section  110 . That is,  FIG. 13  shows the internal state of the valve chamber  47  after the prescribed time has elapsed since the valve  77  arrived in the second state. Once the prescribed time has elapsed, the internal pressure of the ink chamber  36  has reached atmospheric pressure. Thus, the difference between the internal pressure of the ink chamber  36  and atmospheric pressure is less than the threshold value. In other words, the value obtained by subtracting the value of the pressure applied to the second surface  159  of the end wall  154  from the value of the pressure applied to the first surface  158  of the end wall  154  is less than the threshold value. Accordingly, the end wall  154 , which was deflected due to the internal pressure of the ink chamber  36  being applied to the first surface  158 , is now relaxed. Accordingly, the end wall  154  has moved to its open state, separating the annular rib  156  from the surface  151 D of the disc part  151 A. Thus, the liquid channel is open at the position between the end wall  154  and columnar portion  151 . 
     Consequently, ink in the ink chamber  36  can flow out of the ink cartridge  30  through the communication path  130 , second valve chamber  47 B, first space  148 , gaps between the neighboring two anchoring parts  153  juxtaposed in the circumferential direction of the body portion  150 , the opening  81 B formed in the cylindrical wall  155 , the space formed in the through-hole  81  between the outer circumferential surface of the body portion  150  and the inner circumferential surface of the cylindrical wall  155 , the opening  81 A formed in the cylindrical wall  155 , gaps between the neighboring two contact parts  151 B juxtaposed in the circumferential direction of the body portion  150 , the space between the end wall  154  and columnar portion  151 , the second space  149 , the communication holes  104 , and the liquid channel formed inside the ink needle  102 . 
     &lt;Method of Manufacturing the Ink Cartridge  30 &gt; 
     Next, the method (process) of manufacturing the ink cartridge  30  according to the first embodiment will be described with reference to  FIG. 14 . 
     In order to manufacture the ink cartridge  30 , first in S 1 , a molding step is performed to mold the frame  31 . The frame  31  is typically formed through injection molding in which resin is poured into a die. Here, a retractable pin is arranged in the die in a region that will become the hollow space in the cylindrical wall  46  so that resin does not flow into the hollow space. When the frame  31  is molded in this way, the first valve chamber  47 A is formed in the location of the pin. 
     Next, an assembling step is performed in S 2 . In this assembling step, the valve  77  and other components are arranged inside the frame  31  or attached to the frame  31 . 
     Specifically, in the assembling step, the coil spring  86  is first inserted into the second valve chamber  47 B through the aperture  66  (see  FIG. 5 ). Next, the valve  77  is inserted into the first valve chamber  47 A through the opening formed in the downstream end of the cylindrical wall  46  in the mounting direction  51  and is arranged in the first valve chamber  47 A. At this time, one end of the coil spring  86  is in contact with the second inner wall  142 , while the other end is in contact with the anchoring parts  153  of the valve  77 . 
     Next in the assembling step, the sealing member  70  is fitted into the cap  72 . Once the sealing member  70  has been fitted into the cap  72 , the downstream end of the cylindrical wall  46  in the mounting direction  51  is fitted into the cap  72 . In this state, the sealing member  70  is interposed between the cap  72  and cylindrical wall  46 . Alternatively, the sealing member  70  may be fitted into the downstream end of the cylindrical wall  46  in the mounting direction  51 , and subsequently the downstream end of the cylindrical wall  46  in the mounting direction  51  may be fitted into the cap  72  so that the cap  72  covers the sealing member  70 . 
     Next, in S 3 , an attaching step is performed to attach the films  37  and  38 . The films  37  and  38  are attached to the corresponding sides of the frame  31  through heat-sealing or high-frequency welding. Attaching the film  37  closes the right edges of the ink chamber  36 , second valve chamber  47 B, and communication path  130 . The film  37  also closes the right edges of the first air channel  60  excluding the groove  60 D, and the second air channel  63 . Attaching the film  38  closes the left edges of the ink chamber  36  and communication path  130 , as well as the left edge of the groove  60 D constituting the first air channel  60 . 
     Next, a decompressing step is performed in S 4  to reduce pressure in the ink chamber  36  through the air channel. Decompression is performed by connecting a pressure reducing valve to the opening  62  in order to lower the pressure in the ink chamber  36  below atmospheric pressure. After the ink chamber  36  has been decompressed, the pressure reducing valve is closed to seal the opening  62 . Note that the valve  77  is positioned in the first state due to the urging force of the coil spring  86  during the decompressing step. 
     Next, after the internal pressure in the ink chamber  36  has been reduced below atmospheric pressure in the decompressing step of S 4 , an ink filling step is performed in S 5 . In the ink filling step, the ink chamber  36  is filled with ink through the liquid channel. Ink is introduced into the ink chamber  36  by connecting an ink tank (not shown) containing ink to the cylindrical wall  46  through a tube (not shown), for example. 
     Specifically, one end of the tube is connected to the ink tank. The other end of the tube has a similar configuration to the ink needle  102  of the cartridge-receiving section  110 . Thus, when the other end of the tube is connected to the cylindrical wall  46 , this end pushes the valve  77  in the removing direction  52 , thereby moving the valve  77  from the first state to the second state. When the valve  77  moves to the second state, the interior of the ink chamber  36  is in communication with the tube and the ink chamber  36  can be filled with ink introduced from the ink tank. Note that the air channel does not open when the valve  77  moves from the first state to the second state since the opening  62  was sealed in the decompressing step. 
     Since the pressure within the ink chamber  36  was reduced below atmospheric pressure in the decompressing step, the ink contained in the ink tank can flow into the ink chamber  36  through the tube, valve chamber  47 , and communication path  130 . Since the pressure in the ink chamber  36  is lower than atmospheric pressure, the value obtained by subtracting the value of the pressure applied to the second surface  159  of the end wall  154  from the value of the pressure applied to the first surface  158  of the end wall  154  is less than the threshold value, and hence the end wall  154  is in its open state. Accordingly, the end wall  154  does not interrupt the flow of ink from the ink tank to the ink chamber  36 . 
     Once the ink filling step is completed, a pressure adjusting step is performed in S 6  to adjust the pressure within the ink chamber  36  from its reduced pressure during the filling step. As described above, the pressure within the ink chamber  36  (internal pressure of the ink chamber  36 ) needs to be higher than atmospheric pressure in the first embodiment. Hence, in the pressure adjusting step of S 6 , the pressure in the ink chamber  36  is adjusted to become higher than atmospheric pressure. For example, the pressure within the ink chamber  36  is adjusted to be greater than atmospheric pressure by removing the pressure reducing valve from the opening  62 , or by connecting a pressure increasing valve to the opening  62 . 
     Alternatively, the pressure in the ink chamber  36  may be adjusted to be equivalent to atmospheric pressure in the pressure adjusting step of S 6 . If this is the case, by relocating the ink cartridge  30  to a higher altitude after the ink cartridge  30  has been manufactured so that the atmospheric pressure outside the ink cartridge  30  is lower, the pressure within the ink chamber  36  can be higher than atmospheric pressure. Note that, if the ink chamber  36  is filled with ink until the internal pressure of the ink chamber  36  reaches the atmospheric pressure in the ink filling step, the pressure adjusting step can be automatically performed during the ink filling step. 
     Finally, a sealing step is performed in S 7  to seal the ink chamber  36  from the outside of the ink cartridge  30 . Specifically, the end of the tube inserted into the cylindrical wall  46  is extracted therefrom, allowing the valve  77  to move from the second state back to the first state due to the urging force of the coil spring  86 . When in the first state, the valve  77  (and specifically the protruding part  151 C of the valve  77 ) closes the through-hole  71 , while the air channel is closed by the sealing part  84  positioned between the openings  61  and  64 . In this way, the ink chamber  36  is sealed off from the outside of the ink cartridge  30 . Manufacturing of the ink cartridge  30  is thus completed. 
     &lt;Operations and Technical Advantages of the First Embodiment&gt; 
     When molding the frame  31  according to the first embodiment described above, the pin is disposed in the region of the valve chamber  47  corresponding to the first valve chamber  47 A, but not in a region corresponding to the second valve chamber  47 B, since the area of the valve chamber  47  corresponding to the second valve chamber  47 B is open on the side facing in the rightward direction  55 . Hence, this configuration reduces the required length of the pin disposed in the region corresponding to the valve chamber  47  as a whole when molding the frame  31 . This can reduce a probability that the pin will tilt during the molding step due to pressure applied by resin when the resin is poured into the die. Therefore, the cylindrical wall  46  and the first through fifth inner walls  141 - 145  defining the valve chamber  47  of the ink cartridge  30  can be precisely molded. 
     Further, the valve chamber  47  is made longer in the mounting direction  51  than otherwise, since the coil spring  86  is disposed in the valve chamber  47  in the first embodiment. However, the structure of the first embodiment enables the cylindrical wall  46  and the first through fifth inner walls  141 - 145  defining the valve chamber  47  to be molded precisely. 
     In the first embodiment, the coil spring  86  can be inserted into the second valve chamber  47 B through the aperture  66 , and the aperture  66  can subsequently be closed with the film  37 . 
     In the first embodiment described above, the valve  77  is configured to move so as to allow or interrupt communication between the first air channel  60  and second air channel  63 . Hence, the valve  77  moves over a considerably long range in the mounting and removing directions  51  and  52 , necessitating an increase in the length of the valve chamber  47  in the mounting direction  51 . However, by configuring the second valve chamber  47 B to be open on the side facing in the rightward direction  55 , the cylindrical wall  46  and the first through fifth inner walls  141 - 145  defining the valve chamber  47  can be precisely molded. 
     Further, in the depicted embodiment, the valve  77  passes through the intermediate state while moving from the first state to the second state. Hence, the valve  77  travels a greater distance in the mounting and removing directions  51  and  52 , necessitating an increase in the length of the valve chamber  47  in the mounting direction  51 . However, by configuring the second valve chamber  47 B to be open on the side facing in the rightward direction  55 , the cylindrical wall  46  and the first through fifth inner walls  141 - 145  defining the valve chamber  47  can be precisely molded. 
     Further, since the valve  77  can move between the first state and second state, the structure for opening the through-hole  71  and the air channel can be achieved with the single valve  77 . 
     Further, when the valve  77  is in the first state, ink does not flow out of the ink cartridge  30  because the columnar portion  151  closes the through-hole  71 . Further, the ink chamber  36  is in a closed state, since the sealing part  84  (air channel closing part  157 ) closes the communication between the first air channel  60  and second air channel  63 , thereby closing the air channel. When the valve  77  is in the intermediate state, the ink chamber  36  is made in communication with the atmosphere via the first air channel  60 , the space between the sealing parts  84  and  85 , and the second air channel  63 . On the other hand, ink does not flow out of the ink cartridge  30  because the columnar portion  151  closes the through-hole  71 . When the valve  77  is in the second state, since the columnar portion  151  opens the through-hole  71 , the ink chamber  36  can communicate with the outside of the ink cartridge  30 , enabling ink to flow out of the ink cartridge  30 . Thus, the structure of the first embodiment described above enables the ink chamber  36  to communicate with the atmosphere before ink is able to flow out of the ink cartridge  30 . That is, this arrangement can prevent ink in the ink chamber  36  from flowing out of the ink cartridge  30  due to the internal pressure of the ink chamber  36  when the columnar portion  151  opens the through-hole  71 . 
     If the ink chamber  36  communicates with the outside of the ink cartridge  30  when the pressure in the ink chamber  36  is greater than atmospheric pressure, ink in the ink chamber  36  will flow out of the ink cartridge  30 . However, since the end wall  154  closes the liquid channel even in such cases, the structure of the depict embodiment can prevent ink in the ink chamber  36  from flowing out of the ink cartridge  30 . 
     In the first embodiment described above, the valve  77  can move from the first state to the second state via the intermediate state. The internal pressure of the ink chamber  36  remains higher than atmospheric pressure when the valve  77  is in the intermediate state while moving quickly from the first state to the second state via the intermediate state, just as when the valve  77  is in the first state. However, the pressure in the ink chamber  36  could equalize to atmospheric pressure while the valve  77  is in the intermediate state if the movement of the valve  77  is slow. 
     If the valve  77  is rapidly moved from the first state to the second state via the intermediate state, there is concern that the columnar portion  151  could open the through-hole  71  when the valve  77  arrives in the second state before the internal pressure of the ink chamber  36  can equalize to atmospheric pressure after air is allowed to communicate between the openings  61  and  64  in the intermediate state. In such a case, ink could flow out of the ink cartridge  30  due to the internal pressure of the ink chamber  36 . However, according to the structure of the first embodiment, since the end wall  154  keeps the liquid channel closed even in this case, ink in the ink chamber  36  can be prevented from flowing out of the ink cartridge  30 . Naturally, the pressure in the ink chamber  36  could equalize to atmospheric pressure when the valve  77  is in the intermediate state if the movement of the valve  77  is slow. In this case, the end wall  154  opens the liquid channel while the valve  77  is still in the intermediate state. 
     The end wall  154  can close the liquid channel as long as the value obtained by subtracting the value of the pressure applied to the second surface  159  from the value of the pressure applied to the first surface  158  is equal to or greater than the threshold value, even if the columnar portion  151  has opened the through-hole  71  while the air channel is closed by the air channel closing part  157  (sealing parts  84  and  85 ). This arrangement can prevent ink in the ink chamber  36  from flowing out of the ink cartridge  30  via the liquid channel and the through-hole  71 . 
     When the air channel closing part  157  subsequently opens the air channel (the space between the sealing parts  84  and  85  is in communication with the openings  61  and  64 ), the internal pressure of the ink chamber  36  becomes equal to atmospheric pressure. As a result, the value obtained by subtracting the pressure applied to the second surface  159  of the end wall  154  from the pressure applied to the first surface  158  becomes less than the threshold value, causing the end wall  154  to open the liquid channel. Thus, ink in the ink chamber  36  can now flow out of the ink cartridge  30  through the through-hole  71 . 
     The threshold value is set larger than a value obtained by subtracting the value of the pressure applied to the second surface  159  of the end wall  154  when the purging mechanism  120  draws ink from the nozzles  29  of the recording head  21  from the value of the pressure applied to the first surface  158  while the air channel is in an open state. Accordingly, the end wall  154  does not close the liquid channel even when the purging mechanism  120  is drawing ink. In other words, the end wall  154  does not prevent the purging mechanism  120  from conducting its suction operation. 
     Note that the pressure applied to the second surface  159  while the recording head  21  ejects ink is greater than the pressure applied to the second surface  159  when the purging mechanism  120  draws ink from the nozzles  29  of the recording head  21 . Hence, the end wall  154  does not prevent the recording head  21  from performing ink ejection operations. 
     Further, if the ink cartridge  30  were not provided with the sealing part  87 , the ink chamber  36  would be in communication with the valve chamber  47  via the opening  64  when the valve  77  was in the first state. As a consequence, air in the ink chamber  36  could enter the valve chamber  47  via the second air channel  63 , depending on the orientation of the ink cartridge  30 . When the valve  77  was then moved into the second state in order to supply ink outside the ink cartridge  30 , the air that entered the valve chamber  47  could exit the ink cartridge  30  through the through-hole  71 , instead of the ink. However, in the first embodiment, the sealing part  87  interrupts the flow of ink between the opening  64  and valve chamber  47  when the valve  77  is in the first state. Accordingly, air is suppressed from exiting the ink cartridge  30  through the through-hole  71  when the valve  77  is in the second state. 
     Further, when the valve  77  is moved in the removing direction  52  from the first state toward the second state, the sealing part  87  is moved to the same position as the recessed parts  67  and  68  in the mounting and removing directions  51  and  52  and is separated from the wall surfaces configuring the valve chamber  47 . In this way, frictional resistance generated between the valve  77  and the wall surfaces can be reduced when the valve  77  moves in the removing direction  52 , thereby enabling the valve  77  to move smoothly in the removing direction  52 . 
     Since the air channel closing part  157  (the sealing parts  84  and  85 ) and end wall  154  are integrally configured, the number of parts required in the ink cartridge  30  can be reduced 
     Further, by providing the valve  77  with the columnar portion  151  and air channel closing part  157  (sealing parts  84  and  85 ), the single valve  77  can open the through-hole  71  and the air channel. Accordingly, this configuration can further reduce the number of required parts in the ink cartridge  30 . 
     The sealing part  87  has an annular shape in the first embodiment when viewed in the mounting direction  51 . The sealing part  87  with such a simple structure can interrupt the flow of ink between the opening  64  and valve chamber  47 . 
     Further, since the sealing parts  84 ,  85 , and  87  and the inner circumferential surface of the cylindrical wall  46  are annular shaped with a circular cross section, the sealing parts  84 ,  85 , and  87  can uniformly contact the inner circumferential surface of the cylindrical wall  46 . 
     Still further, the coil spring  86  is provided for urging the valve  77  in the mounting direction  51  toward the first state. Therefore, the valve  77  can close the through-hole  71  when no force other than the coil spring  86  is applied to the valve  77 . This arrangement reduces the probability that ink in the ink chamber  36  will flow out of the ink cartridge  30 . 
     When the ink cartridge  30  is in its operational state, ink stored in the ink chamber  36  flows out of the ink cartridge  30  through the valve chamber  47  provided in the bottom of the ink chamber  36 . Accordingly, the ink cartridge  30  can be used until the ink stored in the ink chamber  36  has run out. 
     Further, in the process of manufacturing the ink cartridge  30  according to the first embodiment, the internal pressure of the ink chamber  36  is reduced during the decompressing step, facilitating the operation to fill the ink chamber  36  with ink in the ink filling step. Further, the pressure in the ink chamber  36  is set greater than atmospheric pressure in the pressure adjusting step to allow the end wall  154  to deflect into the closed state to close the liquid channel. Hence, this process can reduce the potential for ink flowing out of the ink cartridge  30  attributed to the internal pressure of the ink chamber  36 . 
     2. Second Embodiment 
     Next, a structure according to a second embodiment will be described with reference to  FIG. 15 . 
     In the second embodiment, structures corresponding to the second valve chamber  47 B and in the vicinity thereof differ from those in the first embodiment. The remaining structure of the ink cartridge of the second embodiment is generally the same as that in the first embodiment. Hence, the following description focuses on structural parts that differ from the first embodiment, while like parts and components are designated by the same reference numerals as those of the first embodiment to avoid duplicating description. It should be also noted that in  FIG. 15 , the first opening  61  and the second opening  64  are omitted. 
     Specifically, a valve chamber  247  according to the second embodiment includes the first valve chamber  47 A and a second valve chamber  247 B. 
     A coil spring  286  is disposed in the second valve chamber  247 B. The coil spring  286  has a dimension greater than the dimension of the first valve chamber  47 A in a direction orthogonal to the mounting and removing directions  51  and  52  (i.e., in the downward and upward directions  53  and  54 , as well as in the rightward and leftward directions  55  and  56  in the second embodiment, and hereinafter, simply referred to as “orthogonal direction”). That is, the coil spring  286  has an outer diameter larger than the inner diameter of the first valve chamber  47 A. The second valve chamber  247 B is configured large enough to allow insertion and deployment of the coil spring  286  therein. In other words, the second valve chamber  247 B has a greater dimension than the coil spring  286  in the orthogonal direction. 
     In the first embodiment, as illustrated in  FIG. 5A , the recessed part  68  is formed in the fifth inner wall  145  and the recessed part  67  is formed in the first inner wall  141 . However, in the second embodiment, these recessed parts  67  and  68  are not formed. Instead, in the second embodiment, as shown in  FIG. 15 , a fifth inner wall  245  has a surface  245 A facing the second valve chamber  247 B that is positioned lower than the bottom edge of the inner circumferential surface of the cylindrical wall  46 . Further, although not discernible in  FIG. 15 , a first inner wall  241  has a surface  241 A facing the second valve chamber  247 B that is positioned farther leftward than the left edge of the inner circumferential surface of the cylindrical wall  46 . Further, a fourth inner wall  244  has a surface  244 A facing the second valve chamber  247 B that is positioned higher than the top edge of the inner circumferential surface of the cylindrical wall  46 , and the film  37  (see  FIG. 4 ) is positioned farther rightward than the right edge of the inner circumferential surface of the cylindrical wall  46 . 
     With this construction, the surfaces extending in the mounting direction  51  that defining the second valve chamber  247 B (i.e., the surfaces  241 A,  244 A, and  245 A, and the surface of the film  37  facing the second valve chamber  247 B) are positioned radially outward of the inner circumferential surface of the cylindrical wall. In this way, the coil spring  286  having a larger outer diameter than the inner diameter of the first valve chamber  47 A is disposed in the second valve chamber  247 B. 
     Note that a valve  277  (retaining part  279 ) of the second embodiment has a downstream end in the removing direction  52  (anchoring parts  253 ) that protrudes from the first valve chamber  47 A into the second valve chamber  247 B. Additionally, an end  286 A of the coil spring  286  positioned downstream in the mounting direction  51  extends from a peripheral portion toward a center region of the coil spring  286  in a radial direction of the same. With this configuration, the end  286 A of the coil spring  286  having a larger outer diameter than the inner diameter of the cylindrical wall  46  can be placed in contact with the anchoring parts  253  of the valve  277  having a smaller diameter than the inner diameter of the cylindrical wall  46 . 
     This structure of the second embodiment can allow use of the coil spring  286  having a larger diameter than the coil spring  86  that can be disposed in the first valve chamber  47 A. The coil spring  286  with a larger diameter can urge the valve  77  with greater force than the coil spring  86  does. 
     3. Third Embodiment 
     Next, a structure according to a third embodiment will be described with reference to  FIGS. 16 and 17 . 
     In the first embodiment described above, the end wall  154  is provided on the valve  77  as a member for opening and closing the liquid channel. However, the member for opening and closing the liquid channel may be provided on a member other than the valve  77 . 
     In an ink cartridge  330  according to the third embodiment, the member for opening and closing the liquid channel is mounted on a frame, unlike in the ink cartridge  30  of the first embodiment. The remaining structure of the ink cartridge  330  according to the third embodiment is generally the same as that in the first embodiment. Accordingly, the following description focuses on structural parts that differ from the first embodiment, while like parts and components are designated with the same reference numerals as those of the first embodiment to avoid duplicating description. 
     Specifically, referring to  FIGS. 16 and 17 , the ink cartridge  330  of the third embodiment includes a frame  331  in which an air channel  390  is formed. The air channel  390  extends from the ink chamber  36  to the outside of the ink cartridge  330  and serves primarily to provide air flow. Specifically, the air channel  390  has one end in communication with the ink chamber  36  via an opening  391  formed in a top inner wall  314 , while another end of the air channel  390  is in communication with the exterior of the ink cartridge  330  through an opening  392  formed in an upper portion of the rear wall  41 . The air channel  390  meanders while extending from the opening  391  to the opening  392 , forming a labyrinthine structure. 
     In other words, the air channel  390  of the third embodiment does not pass through a valve chamber  393  (described later) formed in the frame  331 , unlike the air channel of the first embodiment. 
     As in the first embodiment, the sealing member  70  and cap  72  are mounted in the tip end of the cylindrical wall  46  (the downstream end of the cylindrical wall  46  in the mounting direction  51 ). The base end of the cylindrical wall  46  (the downstream end of the cylindrical wall  46  in the removing direction  52 ) communicates with the ink chamber  36  via a through-hole  395 . 
     The valve chamber  393  is a space defined by the inner circumferential surface of the cylindrical wall  46 . A partitioning wall  394  partitions the valve chamber  393  into a first valve chamber  393 A and a second valve chamber  393 B. The first valve chamber  393 A is formed so as to be offset in the mounting direction  51  from the second valve chamber  393 B. 
     A through-hole  396  is formed in the partitioning wall  394 , penetrating the partitioning wall  394  in the mounting and removing directions  51  and  52 . The first valve chamber  393 A and second valve chamber  393 B are in communication with each other through the through-hole  396 . 
     A liquid channel extends from the ink chamber  36  to the outside of the ink cartridge  330  for primarily providing ink flow. In the third embodiment, the valve chamber  393  serves as the liquid channel. One end of the liquid channel is in communication with the ink chamber  36  via the through-hole  395 , while the other end is in communication with the outside of the ink cartridge  330  via the through-holes  71  and  76 . 
     Within the first valve chamber  393 A, a valve member  397  and a coil spring  398  are disposed. The valve member  397  is positioned offset in the mounting direction  51  from the coil spring  398  (i.e., downstream of the coil spring  398  in the mounting direction  51 ). The valve member  397  is a general columnar-shaped member. One end of the coil spring  398  is in contact with the valve member  397 , while the other end is in contact with the partitioning wall  394 . With this structure, the coil spring  398  can urge the valve member  397  in the mounting direction  51 , thereby maintaining the valve member  397  in a first state in the valve chamber  393 , such that the valve member  397  contacts the sealing member  70 . Note that a plate spring or other urging member may be used in place of the coil spring  398 . The valve member  397  is an example of the first closing part. 
     Within the second valve chamber  393 B, a closing member  399  is disposed as an example of the third closing part. The closing member  399  is configured of a plate-like cover part  399 A, a flexible membrane part  399 B, and a cylindrical part  399 C. The membrane part  399 B surrounds the cover part  399 A and is integrally formed with the cover part  399 A. The cylindrical part  399 C is provided on and along an outer edge of the membrane part  399 B. 
     The cover part  399 A has a surface  388  that confronts the partitioning wall  394  in the mounting and removing directions  51  and  52 , and a surface  389  on the opposite side from the surface  388 . The surface  389  is an example of the first surface and surface  388  is an example of the second surface. 
     The closing member  399  is mounted within the cylindrical wall  46  by inserting the cylindrical part  399 C therein. The cylindrical part  399 C has an outer diameter corresponding to the inner diameter of the cylindrical wall  46 . Therefore, the cylindrical part  399 C can be inserted into the cylindrical wall  46  without play. 
     The surface  388  of the cover part  399 A can contact and separate from the partitioning wall  394  through deflection of the membrane part  399 B. When the surface  388  is in contact with the partitioning wall  394  as shown in  FIG. 16 , the cover part  399 A blocks the through-hole  396 , i.e., closes the liquid channel. However, when the surface  388  is separated from the partitioning wall  394  as shown in  FIG. 17 , the through-hole  396  is opened and, thus, the liquid channel is open. In this way, the closing member  399  can open and close the liquid channel. 
     According to the pressure applied by ink on the surfaces  388  and  389  of the cover part  399 A, the closing member  399  can change between a closed state shown in  FIG. 16  in which the surface  388  contacts the partitioning wall  394  and blocks the liquid channel, and an open state shown in  FIG. 17  in which the surface  388  separates from the partitioning wall  394  and opens the liquid channel. Pressure applied to the surface  389  of the cover part  399 A is ink pressure applied from the second valve chamber  393 B in the mounting direction  51  toward the surface  389 . Pressure applied to the surface  388  is pressure applied by ink in the removing direction  52  from the first valve chamber  93 A toward the surface  388  via the through-hole  396 . 
     The membrane part  399 B deflects so that the closing member  399  shifts to the closed state shown in  FIG. 16  when a value obtained by subtracting the pressure applied to the surface  388  from the pressure applied to the surface  389  is equal to or larger than a threshold value. On the other hand, deflection in the membrane part  399 B is relaxed, allowing the closing member  399  to change to its open state shown in  FIG. 17 , when the value obtained by subtracting the pressure applied to the surface  388  from the pressure applied to the surface  389  is smaller than the threshold value. 
     The threshold value is set based on the thickness and properties of the material composing the membrane part  399 B and cover part  399 A, areas of the surfaces  388  and  389  of the cover part  399 A, and the like. As in the first embodiment, the threshold value in the third embodiment is set larger than a value obtained by subtracting a value of the pressure applied to the surface  388  when the purging mechanism  120  draws ink from the nozzles  29  of the recording head  21  from a value of the pressure applied to the surface  389  when the air channel  390  is open. 
     Prior to the ink cartridge  330  being mounted in the cartridge-receiving section  110 , the valve member  397  is in its first state shown in  FIG. 16  in which the valve member  397  is made to contact the sealing member  70  by the urging force of the coil spring  398 . Thus, in the first state, the valve member  397  seals the through-hole  71 . Consequently, the liquid channel is sealed off from the exterior of the ink cartridge  330  at the position of the through-hole  71 . 
     Further, a seal  100  (an example of a second closing part) is affixed to the rear wall  41  and top wall  39  of the frame  331 . The seal  100  covers the opening  392 , interrupting communication between the interior of the ink chamber  36  and the exterior of the ink cartridge  330 . In other words, the seal  100  prevents the ink chamber  36  from communicating with the atmosphere. Hence, the internal pressure of the ink chamber  36  is not necessarily atmospheric pressure. As in the first embodiment, the internal pressure of the ink chamber  36  when the valve member  397  is in the first state is greater than atmospheric pressure by at least the threshold value in the third embodiment. Note that, in the third embodiment, the rear wall  41  and top wall  39  constitutes outermost walls of the ink cartridge  330 . Accordingly, the user can peel the seal  100  off the rear wall  41  and top wall  39 . 
     Since the internal pressure of the ink chamber  36  is greater than atmospheric pressure by at least the threshold value, the value obtained by subtracting the value of the pressure applied to surface  388  from the value of the pressure applied to the surface  389  of the cover part  399 A is equal to or larger than the threshold value. Therefore, the closing member  399  is set in its closed state, blocking the liquid channel. In other words, the liquid channel is sealed off from the exterior of the ink cartridge  330  at the position of the through-hole  396  in addition to the position of the through-hole  71 . 
     After the ink cartridge  330  is completely mounted in the cartridge-receiving section  110 , the valve member  397  is in the second state shown in  FIG. 17  having been moved in the removing direction  52  from the first state against the urging force of the coil spring  398  by being pushed by the ink needle  102  inserted into the first valve chamber  393 A. At this time, the valve member  397  is separated from the sealing member  70 , thereby opening the through-hole  71 . 
     Normally, the seal  100  is peeled off the ink cartridge  330  prior to the ink cartridge  330  being mounted in the cartridge-receiving section  110 . In this way, the ink chamber  36  is opened to the atmosphere, enabling the internal pressure of the ink chamber  36  to equalize to atmospheric pressure. As a result, the value obtained by subtracting the value of the pressure applied to the surface  388  from the value of the pressure applied to the surface  389  in the closing member  399  is less than the threshold value. Consequently, the closing member  399  changes to its open state, opening the through-hole  396 . 
     Since the through-hole  71  and through-hole  396  are both open when the ink cartridge  330  has been completely mounted in the cartridge-receiving section  110  as described above, the ink stored in the ink chamber  36  can flow out of the ink cartridge  330  through the liquid channel. 
     If the seal  100  were not peeled off the ink cartridge  330  before the ink cartridge  330  was mounted in the cartridge-receiving section  110 , the pressure in the ink chamber  36  would be maintained higher than atmospheric pressure by at least the threshold value. Accordingly, this pressure would attempt to force the ink stored in the ink chamber  36  out of the ink cartridge  330  through the liquid channel. However, since the internal pressure of the ink chamber  36  is greater than atmospheric pressure by at least the threshold value in this case, the closing member  399  is in its closed state and thus prevents the ink flow from the ink chamber  36  to the through-hole  396 . Accordingly, ink cannot flow out of the ink cartridge  330 . 
     4. Modifications and Variations 
     In the first embodiment, portions of the air channel and liquid channel pass through the valve chamber  47 . In the third embodiment, the entire liquid channel passes through the valve chamber  393 . However, the air channel and liquid channel of the present disclosure are not limited to the paths described in the first and third embodiments. For example, the entire air channel may also pass through the valve chamber. 
     In the first embodiment, the columnar portion  151  of the valve  77  is provided with the protruding part  151 C. However, the ink needle  102  may be provided with the protruding part  151 C instead. In this case, the protruding part  151 C constitutes the protruding distal end of the ink needle  102  that protrudes farther in the removing direction  52  than a portion of the ink needle  102  in which the communication holes  104  are formed. Further, when the valve  77  is in the first state, the disc part  151 A of the columnar portion  151  is pressed against the sealing member  70  by the urging force of the coil spring  86 , blocking the through-hole  71 . In other words, the disc part  151 A serves as the first closing part in this case. 
     Alternatively, a member configured to slide while being in close contact with the inner circumferential surface  70 A of the sealing member  70  as the valve  77  moves (the protruding part  151 C in the first embodiment) may be provided on both of the valve  77  and the ink needle  102 . In this case, total lengths in the mounting and removing directions  51  and  52  of the respective members provided on the valve  77  and ink needle  102  is set greater than the length in the mounting and removing directions  51  and  52  between the sealing part  84  and opening  64  when the valve  77  is in the first state and shorter than the length in the mounting and removing directions  51  and  52  between the sealing part  85  and opening  61  when the valve  77  is in the first state. 
     Further, the semipermeable membrane may be attached at any position along the path of the first air channel  60  and is not limited to the position of the annular rib  200  as in the first embodiment. In this case, preferably, the semipermeable member be disposed between the labyrinthine structure  69  and opening  62 , in order to suppress deposits of ink on the semipermeable membrane from inhibiting the circulation of air. 
     In the first embodiment, the sealing part  87  has an annular shape when viewed in the mounting direction  51 . However, the sealing part  87  need not be annular in shape, provided that the sealing part  87  can interrupt the flow of ink between the opening  64  and the liquid channel when the valve  77  is in the first state. 
     For example, the sealing part  87  may be a columnar-shaped protrusion that protrudes radially outward from the outer surface of the cylindrical wall  155 . In this case, the columnar protrusion should have a protruding endface (circular when viewed in the radial direction) that is large enough to entirely cover the opening  64 . With this structure, when the valve  77  is in the first state, this columnar protrusion serving as the sealing part  87  forms a liquid-tight and airtight seal with a portion of the inner circumferential surface of the cylindrical wall  46  that includes the opening  64 . In this way, the columnar-shaped sealing part  87  covers the opening  64 , thereby interrupting the ink flow between the opening  64  and valve chamber  47 . When the valve  77  is moved in the removing direction  52  from the first state, the sealing part  87  moves to a position offset in the removing direction  52  from the opening  64 , whereby ink can flow between the opening  64  and valve chamber  47 . 
     Further, in the first embodiment, the inner circumferential surface of the cylindrical wall  46  and outer circumferential surface of the sealing parts  84 ,  85 , and  87  are circular in shape in a cross section taken orthogonal to the mounting and removing directions  51  and  52 . However, the cross-sectional shapes of these members are not limited to a circular shape and may be elliptical or rectangular, for example. Similarly, the cross-sectional shape of the outer circumferential surface of the cylindrical wall  46  and other components is not limited to be circular. 
     The sealing parts  84 ,  85 , and  87  may be configured of O-rings or the like that fit into circumferential grooves formed in the elastic member  82 , for example. 
     Further, the openings  61  and  64  are formed in the same position in the circumferential direction of the cylindrical wall  46  while being separated from each other in the mounting and removing directions  51  and  52  in the first embodiment, but the positional relationship of these openings  61  and  64  is not limited to the example of the first embodiment. For example, the openings  61  and  64  may be provided at the same position in the mounting and removing directions  51  and  52  while being separated in the circumferential direction of the cylindrical wall  46 , or may be provided at positions separated in both the mounting and removing directions  51  and  52  and the circumferential direction of the cylindrical wall  46 . In such cases, the sealing part  84  may be formed in any shape on the valve  77  as long as the sealing part  84  can interrupt communication between the openings  61  and  64  (i.e., provided that the sealing part  84  is annular and makes a loop around the entire circumference of the elastic member  82 ) when the valve  77  is in the first state. 
     For example, the sealing part  84  may circumscribe the outer circumferential surface of the elastic member  82  along a plane that intersects the mounting and removing directions  51  and  52  (an orthogonal plane in the first embodiment). The sealing part  84  also need not be provided within a single plane, but may curve or meander around the elastic member  82 . In such a case, a portion of the sealing part  84  may extend in the mounting and removing directions  51  and  52 . The same structural modifications may also be applied to the sealing parts  85  and  87 . Further, one of the openings  61  and  64  may be formed in another wall defining the valve chamber  47 , such as the second inner wall  142  or fourth inner wall  144 , rather than the cylindrical wall  46 . 
     Further, while the through-hole  71  formed in the sealing member  70  has a slightly smaller diameter than the outer diameter of the ink needle  102  or the protruding part  151 C of the valve  77  in the above-described embodiments, the present disclosure is not limited to this arrangement. That is, at least part of the through-hole  71  may be closed by the elasticity of the sealing member  70  itself when the ink needle  102  is not inserted in the through-hole  71 . With this configuration, the coil spring  86  ( 286 ,  398 ) need not be provided in the valve chamber  47  ( 247 ,  393 ). If the coil spring  86  ( 286 ,  398 ) is omitted from the valve chamber  47  ( 247 ,  393 ), then once the ink needle  102  has moved the valve  77  ( 277 ,  397 ) to the second state, the valve  77  ( 277 ,  397 ) will remain in the second state even after the ink needle  102  is extracted from the valve chamber  47  ( 247 ,  393 ). Therefore, the valve  77  ( 277 ,  397 ) does not contact the sealing member  70 , but the elasticity of the sealing member  70  can at least partially close the through-hole  71 , thereby suppressing the outflow of ink from the valve chamber  47  ( 247 ,  393 ) through the through-hole  71 . 
     In the first through third embodiments, the ink cartridge  30  ( 330 ) is mounted in the cartridge-receiving section  110  in a horizontal direction, but the direction in which the ink cartridge  30  ( 330 ) moves when being mounted in the cartridge-receiving section  110  is not limited to the horizontal direction, but may be a vertical direction instead. 
     Although ink serves as an example of liquid in the depicted embodiments, the liquid of the present disclosure may be a pretreatment liquid that is ejected onto the recording sheets prior to the ink during a printing operation, for example, instead of ink. 
     While the disclosure has been described in detail with reference to the specific embodiments thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the disclosure.