Patent Publication Number: US-10759178-B2

Title: Liquid supply unit

Description:
This application is a Continuation of U.S. application Ser. No. 15/360,990, filed Nov. 23, 2016; which claims priority to Japanese Patent Application No. 2015-231549, filed Nov. 27, 2015. The entire disclosures of both prior applications are expressly incorporated by reference herein. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a liquid supply unit. 
     2. Related Art 
     Cartridges for supplying ink to printing devices are widely used. JP-A-2013-141804 discloses a structure in which a cartridge is positioned in a printing device by a projection-like restriction portion of the printing device being fit between a pair of restriction walls of the cartridge when the cartridge is mounted to the printing device. 
     JP-A-2013-141804 is an example of related art. 
     SUMMARY 
     In the printing device described in JP-A-2013-141804, the restriction walls of the cartridge are located near an electrode (terminal) of the cartridge. Therefore, it is possible to improve the accuracy of the contact position of the electrode of the cartridge and an electrode of the printing device. However, the restriction walls are separated from a printing material supply port of the cartridge, and thus there is a possibility that the accuracy of the contact position of the printing material supply port and a liquid introduction unit of the printing device will be insufficient. Therefore, there is demand for a technique that can improve the accuracy of both the contact position of the supply port of the cartridge with the printing device and the contact position of the electrode of the cartridge with the printing device. Such a problem is common not only to printing devices and cartridges, but also to liquid ejection apparatuses for ejecting liquid and liquid supply units that are mounted to liquid ejection apparatuses. 
     The present invention has been made in order to solve at least a portion of the above-described problem, and can be realized as the following aspects. 
     1. According to one aspect of the present invention, a liquid supply unit configured to be mounted to a liquid ejection apparatus provided with a sealing member, a projection and an electrode part is provided. This liquid supply unit includes: a liquid supply part configured to supply liquid to the liquid ejection apparatus; an outer peripheral wall that surrounds the liquid supply part and abuts on the sealing member; a plurality of contact portions that come into contact with the electrode part; and a positioning portion that is fitted with the projection. When a plane including a portion in which an end portion of the outer peripheral wall abuts on the sealing member is referred to as a first reference plane, a direction orthogonal to the first reference plane is referred to as a Z axis direction, a direction orthogonal to the Z axis direction is referred to as an X axis direction, a direction orthogonal to the Z axis direction and the X axis direction is referred to as a Y axis direction, and a plane including the plurality of contact portions is referred to as a second reference plane, then, in planar view of the liquid supply unit in the Z axis direction, the positioning portion is positioned between the end portion of the outer peripheral wall and the plurality of contact portions in the X axis direction, while in planar view of the liquid supply unit in the X axis direction, the positioning portion is positioned between the end portion of the outer peripheral wall and the plurality of contact portions in the Z axis direction, and the second reference plane crosses the sealing member. According to the liquid supply unit in such an aspect, it is possible to improve the accuracy of both the contact position of the liquid supply port and the contact position of the contact portions with the liquid ejection apparatus. 
     2. In the liquid supply unit of the above aspect, in planar view of the liquid supply unit in the Z axis direction, the positioning portion may be closer to any one of the plurality of contact portions than to the end portion of the outer peripheral wall in the X axis direction. According to such an aspect, it is possible to improve the accuracy of both the contact position of the liquid supply port of the liquid supply unit and the contact position of the contact portions with the liquid ejection apparatus. 
     3. In the liquid supply unit of the above aspect, in planar view of the liquid supply unit in the X axis direction, the positioning portion may be closer to the end portion of the outer peripheral wall than to the plurality of contact portions in the Z axis direction. According to such an aspect, it is possible to improve the accuracy of both the contact position of the liquid supply port and the contact position of the contact portions with the liquid ejection apparatus. 
     4. The liquid supply unit of the above aspect further includes a first wall portion on which the liquid supply part is formed; a second wall portion that opposes the first wall portion; a third wall portion that intersects the first wall portion and the second wall portion; a fourth wall portion that intersects the first wall portion and the second wall portion and opposes the third wall portion; a fifth wall portion that intersects the first wall portion, the second wall portion, the third wall portion and the fourth wall portion; a sixth wall portion that intersects the first wall portion, the second wall portion, the third wall portion and the fourth wall portion, and opposes the fifth wall portion; and a seventh wall portion that intersects the fifth wall portion and the sixth wall portion, and is positioned between the first wall portion and the fourth wall portion, wherein in planar view of the liquid supply unit in the X axis direction, the positioning portion may be positioned between a face of the first wall portion that opposes the second wall portion and the end portion of the outer peripheral wall in the Z axis direction. According to such an aspect, it is possible to improve the accuracy of the contact position of the liquid supply port with the liquid ejection apparatus. 
     5. In the liquid supply unit of the above aspect, in planar view of the liquid supply unit in the Z axis direction, the positioning portion may be positioned between the seventh wall portion and the end portion of the outer peripheral wall in the X axis direction. According to such an aspect, it is possible to improve the accuracy of the contact position of the liquid supply port with the liquid ejection apparatus. 
     6. In the liquid supply unit of the above aspect, the liquid supply part includes an opening formed in the first wall portion and a filter that covers the opening, and in planar view of the liquid supply unit in the X axis direction, the positioning portion may be positioned between the opening and the end portion of the outer peripheral wall in the Z axis direction. According to such an aspect, it is possible to increase the accuracy of the contact position of the liquid supply part with the liquid ejection apparatus. 
     7. In the liquid supply unit of the above aspect, a distance between the third wall portion and the fourth wall portion may be greater than a distance between the fifth wall portion and the sixth wall portion. 
     8. According to another aspect of the present invention, a liquid ejection apparatus provided with a sealing member, a projection and an electrode part is provided. The liquid ejection apparatus includes the liquid supply unit of the above aspects and a carriage unit to which the liquid supply unit is mounted. The carriage unit may move in the X axis direction. 
     9. According to a second aspect of the present invention, a liquid supply unit configured to be mounted to a liquid ejection apparatus provided with a sealing member, a projection and an electrode part is provided. This liquid supply unit includes: a first wall portion; a second wall portion that opposes the first wall portion; a third wall portion that intersects the first wall portion and the second wall portion; a fourth wall portion that intersects the first wall portion and the second wall portion and opposes the third wall portion; a fifth wall portion that intersects the first wall portion, the second wall portion, the third wall portion and the fourth wall portion; a sixth wall portion that intersects the first wall portion, the second wall portion, the third wall portion and the fourth wall portion, and opposes the fifth wall portion; and a seventh wall portion that intersects the fifth wall portion and the sixth wall portion, and is positioned between the first wall portion and the fourth wall portion. Moreover, the first wall portion is provided with a liquid supply part configured to supply a liquid to the liquid ejection apparatus, an outer peripheral wall that surrounds the liquid supply part and abuts on the sealing member, and a positioning portion that is fitted with the projection, and the seventh wall portion is provided with a plurality of contact portions that come into contact with the electrode part. The first wall portion, the second wall portion, the third wall portion, the fourth wall portion, the fifth wall portion, the sixth wall portion and the seventh wall portion surround a liquid container that communicates with the liquid supply part, and a plane including a face on a liquid container side of the seventh wall portion crosses the liquid supply part. According to the liquid supply unit of such an aspect, it is possible to improve the accuracy of both the contact position of the liquid supply port and the contact position of the contact portions with the liquid ejection apparatus. 
     10. According to a third aspect of the present invention, a liquid supply unit configured to be mounted to a liquid ejection apparatus provided with a sealing member, a projection and an electrode part is provided. This liquid supply unit includes a first wall portion; a second wall portion that opposes the first wall portion; a third wall portion that intersects the first wall portion and the second wall portion; a fourth wall portion that intersects the first wall portion and the second wall portion and opposes the third wall portion; a fifth wall portion that intersects the first wall portion, the second wall portion, the third wall portion and the fourth wall portion; a sixth wall portion that intersects the first wall portion, the second wall portion, the third wall portion and the fourth wall portion and opposes the fifth wall portion; a seventh wall portion that intersects the fifth wall portion and the sixth wall portion and is positioned between the first wall portion and the fourth wall portion; and a substrate provided on the seventh wall portion. Moreover, the first wall portion is provided with a liquid supply part configured to supply a liquid to the liquid ejection apparatus, an outer peripheral wall that surrounds the liquid supply part and abuts on the sealing member, and a positioning portion that is fitted with the projection, and the substrate is provided with a plurality of contact portions that come into contact with the electrode part. The first wall portion, the second wall portion, the third wall portion, the fourth wall portion, the fifth wall portion, the sixth wall portion and the seventh wall portion surround a liquid container that communicates with the liquid supply part, and a plane including a face on a substrate side of the seventh wall portion crosses the sealing member. According to the liquid supply unit of such an aspect, it is possible to improve the accuracy of both the contact position of the liquid supply port and the contact position of the contact portions with the liquid ejection apparatus. 
     11. According to a fourth aspect of the present invention, a liquid supply unit configured to be mounted to a liquid ejection apparatus provided with a sealing member, a projection and an electrode part is provided. This liquid supply unit includes a first wall portion; a second wall portion that opposes the first wall portion; a third wall portion that intersects the first wall portion and the second wall portion; a fourth wall portion that intersects the first wall portion and the second wall portion and opposes the third wall portion; a fifth wall portion that intersects the first wall portion, the second wall portion, the third wall portion and the fourth wall portion; a sixth wall portion that intersects the first wall portion, the second wall portion, the third wall portion and the fourth wall portion, and opposes the fifth wall portion; a seventh wall portion that intersects the fifth wall portion and the sixth wall portion, and is positioned between the first wall portion and the fourth wall portion; and a substrate placed on the seventh wall portion. Moreover, the first wall portion is provided with a liquid supply part configured to supply a liquid to the liquid ejection apparatus, an outer peripheral wall that surrounds the liquid supply part and abuts on the sealing member, and a positioning portion that is fitted with the projection, and the substrate is provided with a plurality of contact portions that come into contact with the electrode part. The first wall portion, the second wall portion, the third wall portion, the fourth wall portion, the fifth wall portion, the sixth wall portion and the seventh wall portion surround a liquid container that communicates with the liquid supply part, and a plane including the plurality of contact portions crosses the sealing member. According to the liquid supply unit of such an aspect, it is possible to improve the accuracy of both the contact position of the liquid supply port and the contact position of the contact portions with the liquid ejection apparatus. 
     12. In the liquid supply unit of the above aspect, a distance between the third wall portion and the fourth wall portion may be greater than a distance between the fifth wall portion and the sixth wall portion. 
     13. According to yet another aspect of the present invention, a liquid ejection apparatus provided with a sealing member, a projection and an electrode part is provided. The liquid ejection apparatus includes the liquid supply unit of the above aspects and a carriage unit to which the liquid supply unit is mounted. The carriage unit may move in a direction from the third wall portion toward the fourth wall portion. 
     The present invention can be achieved in various aspects besides an aspect as the above-described liquid supply unit. For example, the present invention can be achieved in aspects as a liquid ejection apparatus, a liquid supply system, a cartridge, a printing device and the like. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a perspective view showing a schematic configuration of a liquid supply system. 
         FIG. 2  is a first perspective view of a holder. 
         FIG. 3  is a second perspective view of the holder. 
         FIG. 4  is a plan view of the holder viewed from a +Z axis direction side. 
         FIG. 5  is a first external perspective view of a cartridge. 
         FIG. 6  is a second external perspective view of the cartridge. 
         FIG. 7  is a front view of the cartridge. 
         FIG. 8  is a rear view of the cartridge. 
         FIG. 9  is a left side view of the cartridge. 
         FIG. 10  is a right side view of the cartridge. 
         FIG. 11  is a plan view of the cartridge. 
         FIG. 12  is a bottom view of the cartridge. 
         FIGS. 13A, 13B and 13C  are diagrams showing a state in which the cartridge is mounted to the holder. 
         FIG. 14  is a cross-sectional view showing a structure of a liquid supply part. 
         FIG. 15  is a schematic diagram illustrating an internal structure of the cartridge. 
         FIG. 16  is a schematic diagram illustrating an internal structure of the cartridge. 
         FIG. 17  is a schematic diagram illustrating an internal structure of the cartridge. 
         FIG. 18  is an exploded perspective view of the cartridge. 
         FIG. 19  is an XZ cross-sectional view of the cartridge and a carriage unit. 
         FIG. 20  is an explanatory view showing an effect of a positioning portion. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     A. Embodiment 
       FIG. 1  is a perspective view showing the schematic configuration of a liquid supply system  10 . In  FIG. 1 , X, Y and Z axes that are orthogonal to each other are illustrated. The X, Y and Z axes in  FIG. 1  are the same as X, Y and Z axes in other figures. The liquid supply system  10  is provided with a cartridge  20  serving as a liquid supply unit and a printer  50  serving as a liquid ejection apparatus. In the liquid supply system  10 , the cartridge  20  is removably mounted by the user to a holder  60  of the printer  50 . For example, the printer  50  is provided with a sealing member, a projection and an electrode part, as will be described later. 
     The cartridge  20  of the liquid supply system  10  contains ink as serving a printing material (liquid). The ink contained in the cartridge  20  is supplied to a head  540  via a liquid supply part and a liquid introduction unit, which will be described later. In this embodiment, a plurality of cartridges  20  are removably mounted to the holder  60  of the printer  50 . In this embodiment, six types of cartridges  20  in one-to-one correspondence with ink of six colors (black, yellow, magenta, light magenta, cyan and light cyan), that is, six cartridges  20  in total are mounted to the holder  60 . 
     In another embodiment, the number of cartridges that are mounted to the holder  60  may be six or less, or may be six or more. In another embodiment, the number of types of ink for the cartridge  20  may be six or less, or may be six or more. In another embodiment, two or more cartridges  20  for ink of one color may be mounted to the holder  60 . The detailed configurations of the cartridge  20  and the holder  60  will be described later. 
     The printer  50  is a small-sized inkjet printer for personal use. The printer  50  is provided with, in addition to the holder  60 , a control unit  510  and a carriage unit  520  having the holder  60 . The carriage unit  520  is provided with the head  540 . The printer  50  causes ink to flow from the cartridge  20  mounted in the holder  60  to the head  540  via the liquid introduction unit that will be described later, and discharges (supplies) the ink from the head  540  to a printing medium such as a sheet or a label. Accordingly, data such as characters, graphics and images are printed onto the printing medium using the head  540 . 
     The control unit  510  of the printer  50  controls each constituent element of the printer  50 . The carriage unit  520  of the printer  50  is configured to be able to move the head  540  relative to a printing medium. The head  540  of the printer  50  is provided with an ink discharge mechanism for discharging ink contained in the cartridge  20  to a printing medium. The control unit  510  and the carriage unit  520  are electrically connected via a flexible cable  517 , and the ink discharge mechanism of the head  540  is operated based on control signals from the control unit  510 . 
     In this embodiment, the holder  60  as well as the head  540  are formed on the carriage unit  520 . The type of the printer  50  in which the cartridge  20  is mounted to the holder  60  on the carriage unit  520  that moves the head  540  as described above is referred to as an “on-carriage type”. In another embodiment, a configuration may be adopted in which the holder  60  that is immovable is formed at a position that is different from the position of the carriage unit  520 , and ink from the cartridge  20  mounted in the holder  60  is supplied to the head  540  of the carriage unit  520  via a flexible tube. The type of such a printer is referred to as an “off-carriage type”. 
     In this embodiment, the printer  50  is provided with a main scanning feeding mechanism and a sub scanning feeding mechanism for realizing printing on a printing medium by relatively moving the carriage unit  520  and the printing medium. The main scanning feeding mechanism of the printer  50  is provided with a carriage motor and a driving belt, and reciprocally moves the carriage unit  520  in a main scanning direction by transmitting the motive power of the carriage motor to the carriage unit  520  via the driving belt. The sub scanning feeding mechanism of the printer  50  is provided with a conveyance motor and a platen, and conveys a printing medium in a sub-scanning direction orthogonal to the main scanning direction by transmitting the motive power of the conveyance motor to the platen. The carriage motor of the main scanning feeding mechanism and the conveyance motor of the sub scanning feeding mechanism are operated based on control signals from the control unit  510 . 
     In this embodiment, in a usage state of the liquid supply system  10  (also referred to as a “usage orientation”), an axis along the sub-scanning direction (the front-rear direction) in which a printing medium is conveyed is referred to as a Y axis, an axis along the main scanning direction (the right-left direction) in which the carriage unit  520  is reciprocally moved is referred to as an X axis, and an axis along the gravity direction (the up-down direction) is referred to as a Z axis. Note that the usage state of the liquid supply system  10  is a state in which the liquid supply system  10  is installed on the horizontal plane, and in this embodiment, the horizontal plane is a plane parallel to the X axis and the Y axis (an XY plane). 
     In this embodiment, the sub-scanning direction (the forward direction) is referred to as a +Y axis direction and the opposite direction (the backward direction) is referred to as a −Y axis direction, and a direction upward from below in the gravity direction (the upward direction) is referred to as a +Z axis direction and the opposite direction (the downward direction) is referred to as a −Z axis direction. In this embodiment, a +Y axis direction side is in front of the liquid supply system  10 . In this embodiment, a direction from the left side face toward the right side face of the liquid supply system  10  is referred to as a +X axis direction (the right direction), and the opposite direction is referred to as a −X axis direction (the left direction). In this embodiment, the alignment direction of a plurality of cartridges  20  mounted to the holder  60  is a direction along the Y axis (the front-rear direction, simply referred to as a “Y axis direction” as well). Note that a direction along the X axis (the right-left direction) is also referred to as an “X axis direction”, and a direction along the Z axis (the up-down direction) is also referred to as a “Z axis direction”. 
       FIG. 2  is a first perspective view of the holder  60 .  FIG. 3  is a second perspective view of the holder  60 .  FIG. 4  is a plan view of the holder  60  as viewed from the +Z axis direction side. 
     As shown in  FIGS. 2 to 4 , the holder  60  has five wall portions  601 ,  603 ,  604 ,  605  and  606 . A recess portion formed by these five wall portions serves as a cartridge housing chamber  602  (also referred to as a “cartridge mounting part  602 ”). Hereinafter, the wall portion  601  is also referred to as a bottom wall portion  601 . The cartridge housing chamber  602  is divided by partitions  607  into a plurality of slots (mounting spaces) that can respectively accommodate the cartridges  20 . The partitions  607  function as guides for inserting the cartridges  20  into the slots. A liquid introduction unit  640 , an electrode part  61 , a lever  80 , a projection  610 , and a restriction portion  620  of the apparatus ( FIG. 3 ) are provided for each of the slots. One face (a face in the +Z axis direction, namely, a top face) of each of the slots is open, and the cartridge  20  is mounted/removed to/from the holder  60  via this one open face (top face). The liquid introduction unit  640  is provided so as to be sandwiched between two partitions  607 . 
     The projection  610  is a substantially rectangular parallelepiped member that protrudes from the bottom wall portion  601  in the +Z axis direction. The projection  610  is inserted into a positioning portion provided on the cartridge  20 . In order to make it easy to insert the projection  610  of the cartridge  20  into the positioning portion, the faces of a tip portion of the projection  610  on a +X axis direction side and on a −X axis direction side are inclined to be closer to each other toward the tip. 
     The cartridge  20  is mounted to the holder  60  by being locked by the lever  80  and the restriction portion  620  of the apparatus and the liquid supply part to be described later being connected to the liquid introduction unit  640 . At this time, the cartridge  20  is positioned in the cartridge housing chamber  602  by the projection  610 . This state is also referred to as a “state in which the cartridge  20  is mounted to the holder  60 ” or as a “mounted state”. In the mounted state, a group of terminals provided on a circuit substrate (to be described later) of the cartridge  20  is electrically connected to the electrode part  61 , whereby various types of information is transmitted between the cartridge  20  and the printer  50 . 
     The liquid introduction unit  640  circulates ink contained in the cartridge  20  to the head  540  by being connected to the liquid supply part of the cartridge  20  in the mounted state. The liquid introduction unit  640  is substantially cylindrical, and has a top end portion  642  positioned on the +Z axis side, and a base end portion  645  positioned on the −Z axis side. The base end portion  645  is provided on the bottom wall portion  601 . The top end portion  642  is connected to the liquid supply part of the cartridge  20 . A filter  643  of the apparatus is provided on the top end portion  642 . Ink flows from the liquid supply part of the cartridge  20  into the liquid introduction unit  640  through the filter  643  of the apparatus. The filter  643  of the apparatus is formed by a porous member such as a metal mesh filter, a metal nonwoven fabric filter, or a resin filter. A central axis C of the liquid introduction unit  640  is parallel to the Z axis. A direction along the central axis C from the base end portion  645  toward the top end portion  642  is the +Z axis direction. 
     As shown in  FIGS. 3 and 4 , a sealing member  648  is provided on the periphery of the liquid introduction unit  640 . The sealing member  648  is formed by elastic rubber, for example. In the mounted state, the sealing member  648  seals the liquid supply part of the cartridge  20  at its periphery. Accordingly, the sealing member  648  prevents ink from leaking from the liquid supply part to the surroundings. In the mounted state, the sealing member  648  applies a biasing force including a +Z axis direction component to the cartridge  20 . 
       FIG. 5  is a first external perspective view of the cartridge  20 .  FIG. 6  is a second external perspective view of the cartridge  20 .  FIG. 7  is a front view of the cartridge  20 .  FIG. 8  is a rear view of the cartridge  20 .  FIG. 9  is a left side view of the cartridge  20 .  FIG. 10  is a right side view of the cartridge  20 .  FIG. 11  is a plan view of the cartridge  20 .  FIG. 12  is a bottom view of the cartridge  20 . The cartridge  20  of this embodiment is a so-called semi-sealed type cartridge that intermittently introduces external air into a liquid container  200  in accordance with the ink consumption. 
     The cartridge  20  is provided with the liquid container  200  ( FIG. 5 ) for containing ink therein, a liquid supply part  280  ( FIG. 6 ) for supplying the ink in the liquid container  200  to the printer  50 , an outer peripheral wall  288  ( FIG. 6 ) that surrounds the liquid supply part  280  and abuts on the sealing member  648  of the holder  60 , a plurality of contact portions  16  ( FIG. 6 ) that come into contact with the electrode part  61  of the holder  60 , and a positioning portion  30  ( FIG. 6 ) that fits with the projection  610  of the holder  60 . 
     As shown in  FIGS. 5 and 6 , the cartridge  20  has an outer shell  22  that is substantially rectangular parallelepiped-shaped. The outer shell  22  has seven wall portions  201  to  207 . The seven wall portions consist of the first wall portion  201  (bottom wall  201 ), the second wall portion  202  (upper wall  202 ), the third wall portion  203  (one end wall  203 ), the fourth wall portion  204  (the other end wall  204 ), the fifth wall portion  205  (one side wall  205 ), the sixth wall portion  206  (the other side wall  206 ) and the seventh wall portion  207  (inclined wall  207 ). The first wall portion  201 , the second wall portion  202 , the third wall portion  203 , the fourth wall portion  204 , the fifth wall portion  205 , the sixth wall portion  206  and the seventh wall portion  207  surround the liquid container  200  that communicates with the liquid supply part  280 . 
     In the following description, the meaning of two wall portions “crossing” or “intersecting” each other includes any of a state in which the two wall portions are connected with and cross each other, a state in which an extension plane of one of the wall portions crosses the other wall portion, and a state in which extension planes of the wall portions cross each other. Moreover, the meaning of two wall portions “opposing” each other includes both a case in which another object is not present between the two wall portions and a case in which another object is present. 
     The outer surfaces of the wall portions  201  to  207  are generally flat. The meaning of “generally flat” includes a case in which an entire surface is completely flat and a case in which a portion of a surface includes roughness. Accordingly, a case is included in which, even if a portion of a surface includes slight roughness, surfaces and walls that constitute the outer shell  22  of the cartridge  20  can be recognized. In planar view, the outer shapes of the first wall portion  201  to the seventh wall portion  207  are all rectangular. In this embodiment, the first wall portion  201  to the seventh wall portion  207  may be the outer surfaces of an assembly obtained by assembling a plurality of members. In this embodiment, the first wall portion  201  to the seventh wall portion  207  are plate-like. In another embodiment, the first wall portion  201  to the seventh wall portion  207  may be partially formed by a film-like (thin film-like) member. The first wall portion  201  to the seventh wall portion  207  are formed by synthetic resin such as polyacetal (POM). 
     As shown in  FIGS. 5 and 6 , the first wall portion  201  and the second wall portion  202  are wall portions that are parallel to the X axis and the Y axis. The second wall portion  202  opposes the first wall portion  201 . In other words, the first wall portion  201  and the second wall portion  202  oppose each other in the Z axis direction. The first wall portion  201  is positioned on the −Z axis direction side, and the second wall portion  202  is positioned on the +Z axis direction side. The first wall portion  201  and the second wall portion  202  are in a positional relationship of crossing the third wall portion  203 , the fourth wall portion  204 , the fifth wall portion  205  and the sixth wall portion  206 . In this embodiment, in the mounted state in which the cartridge  20  is mounted to the holder  60 , the first wall portion  201  constitutes the bottom face of the cartridge  20 , and the second wall portion  202  constitutes the top face of the cartridge  20 . The liquid supply part  280 , the outer peripheral wall  288  and the positioning portion  30  are provided on the first wall portion  201 . 
     The third wall portion  203  and the fourth wall portion  204  are wall portions that are parallel to the Y axis and the Z axis. The third wall portion  203  and the fourth wall portion  204  oppose each other in the X axis direction. The third wall portion  203  is positioned on the −X axis direction side, and the fourth wall portion  204  is positioned on the +X axis direction side. The third wall portion  203  intersects the first wall portion  201  and the second wall portion  202 . The fourth wall portion  204  intersects the first wall portion  201  and the second wall portion  202 , and opposes the third wall portion  203 . As described earlier, in this embodiment, the carriage unit  520  reciprocally moves in the X axis direction. Accordingly, the direction of movement of the carriage unit  520  is a direction from the third wall portion  203  toward the fourth wall portion  204 , or a direction from the fourth wall portion  204  toward the third wall portion  203 . 
     The fifth wall portion  205  and the sixth wall portion  206  are wall portions that are parallel to the X axis and the Z axis. The fifth wall portion  205  and the sixth wall portion  206  oppose each other in the Y axis direction. The fifth wall portion  205  intersects the first wall portion  201 , the second wall portion  202 , the third wall portion  203  and the fourth wall portion  204 . The sixth wall portion  206  intersects the first wall portion  201 , the second wall portion  202 , the third wall portion  203  and the fourth wall portion  204 , and opposes the fifth wall portion  205 . As shown in  FIG. 5 , a ventilation port  290  for introducing air into the cartridge  20  is formed in the sixth wall portion  206 . In this embodiment, as shown in  FIG. 12 , a distance LX between the third wall portion  203  and the fourth wall portion  204  is greater than a distance LY between the fifth wall portion  205  and the sixth wall portion  206 . 
     As shown in  FIG. 6 , the positioning portion  30  that is recessed in the +Z axis direction is provided at the end portion of the first wall portion  201  on the seventh wall portion  207  side. Specifically, the positioning portion  30  is arranged between the liquid supply part  280  arranged on the first wall portion  201  and a substrate  15  arranged on the seventh wall portion  207 . The positioning portion  30  is a recess portion provided in the first wall portion  201 . In the mounted state, the projection  610  provided on the holder  60  is inserted and fitted into the positioning portion  30 . Accordingly, the cartridge  20  is positioned in the holder  60 . 
     As shown in  FIGS. 6 and 10 , a first restriction portion  210  of the cartridge (a rib  210  on one side) is formed on the fourth wall portion  204 . The first restriction portion  210  of the cartridge is a projection provided so as to protrude from the fourth wall portion  204 . In the mounted state, the first restriction portion  210  of the cartridge is locked by the lever  80 . As shown in  FIGS. 5 and 9 , a second restriction portion  221  of the cartridge (a rib  221  on the other side) is formed on the third wall portion  203 . The second restriction portion  221  of the cartridge is a projection provided so as to protrude from the third wall portion  203 . In the mounted state, the second restriction portion  221  of the cartridge is inserted into and locked by the restriction portion  620  of the apparatus, which is a hole formed in a wall portion  604  of the holder  60  ( FIG. 3 ). Accordingly, in the mounted state, the cartridge  20  is locked by the lever  80  of the holder  60  and the restriction portion  620  of the apparatus respectively on the +X axis direction side and the −X axis direction side, whereby the cartridge  20  is fixed to the holder  60 . 
     As shown in  FIG. 6 , the seventh wall portion  207  is a wall portion that connects the first wall portion  201  and the fourth wall portion  204 . The seventh wall portion  207  intersects the fifth wall portion  205  and the sixth wall portion  206 , and is positioned between the first wall portion  201  and the fourth wall portion  204 . The substrate  15  is provided on the seventh wall portion  207 . The substrate  15  has the plurality of contact portions  16  that are to come into contact with the electrode part  61  provided on the holder  60  in the mounted state. More specifically, the contact portions  16  are areas that are in terminals for electrodes provided on the surface of the substrate  15  and come into contact with the electrode part  61 . In this embodiment, the plurality of contact portions  16  form a first row R 1  and a second row R 2  with a predetermined interval in the X axis direction, as viewed from the −Z axis direction. A storage apparatus  18  ( FIG. 18 ) that stores various types of information regarding the cartridge  20  is provided on the back face of the substrate  15 . The storage apparatus  18  stores information indicating an ink remaining state and an ink color, for example. When the electrode part  61  provided on the holder  60  is brought into contact with the contact portions  16 , the control unit  510  provided in the printer  50  can read various types of information from the storage apparatus  18  provided in the cartridge  20 , through the flexible cable  517 . 
     The electrode part  61  provided on the holder  60  has elastic force, and in the mounted state, the contact portions  16  receive a repulsive force from the electrode part  61  in the +Z direction and the −X direction. Movement of the cartridge  20  in the +Z direction and the −X direction is restricted by the positioning portion  30 , the first restriction portion  210  of the cartridge, and the second restriction portion  221  of the cartridge, while the contact portions  16  receive a repulsive force from the electrode part  61  in the +Z direction and the −X direction, and thereby the contact portions  16  and the electrode part  61  easily keep a contact state. 
       FIGS. 13A, 13B and 13C  are diagrams showing a state in which the cartridge  20  is mounted to the holder  60 . When the cartridge  20  is mounted to the holder  60 , first, as shown in  FIG. 13A , the second restriction portion  221  of the cartridge is inserted into the restriction portion  620  of the apparatus. The cartridge  20  is then inserted into the holder  60  while being rotated with respect to the vicinity in which the restriction portion  620  of the apparatus and the second restriction portion  221  of the cartridge come into contact with each other. As shown in  FIG. 13B , the cartridge  20  then stops in a state where the fourth wall portion  204  of the cartridge  20  is slightly raised. Next, when, from this state, the cartridge  20  is pressed in against the repulsion force from the electrode part  61  of the holder  60 , the projection  610  is inserted into the positioning portion  30 , and the liquid supply part  280  and the liquid introduction unit  640  come into contact with each other. Lastly, as shown in  FIG. 13C , the first restriction portion  210  of the cartridge is locked by the lever  80 , and the cartridge  20  is fixed to the holder  60 . When the cartridge  20  is removed from the holder  60 , conversely, the locking of the lever  80  by the first restriction portion  210  of the cartridge is first released. The cartridge  20  is lifted due to the repulsion force from the electrode part  61  of the holder  60  until a state shown in  FIG. 13B  is entered. After that, the cartridge  20  is lifted while being rotated with respect to the vicinity in which the restriction portion  620  of the apparatus and the second restriction portion  221  of the cartridge come into contact with each other, and furthermore, the cartridge  20  is pulled out of the holder  60 , whereby the cartridge  20  is removed from the holder  60 . 
       FIG. 14  is a cross-sectional view showing the structure of the liquid supply part  280 . In  FIG. 14 , the internal structure of the cartridge  20  except for the liquid supply part  280  is omitted. The liquid supply part  280  includes an opening  277 , a filter  36  of the cartridge that covers the opening  277  on the outside face side of the first wall portion  201 , and a liquid supply port  281 . In this embodiment, the liquid supply part  280  further includes foam  34  and a leaf spring  35 . 
     The liquid supply part  280  communicates with the liquid container  200  via the opening  277 . The opening  277  is a hole that penetrates the first wall portion  201  in the Z axis direction. The filter  36  of the cartridge is arranged on the −Z axis direction side of the opening  277 . The filter  36  of the cartridge is welded to the first wall portion  201  at the periphery of the opening  277 . The filter  36  of the cartridge is formed by woven fabric, nonwoven fabric, or foamable resin (foam), for example. The leaf spring  35  made of metal is arranged on the opening  277  side between the opening  277  and the filter  36  of the cartridge, and the foam  34  is arranged on the filter  36  side of the cartridge. 
     When mounting the cartridge  20  to the holder  60 , the leaf spring  35  indirectly presses the filter  36  of the cartridge against the filter  643  of the apparatus via the foam  34  so as to bring the filter  36  of the cartridge and the filter  643  of the apparatus into contact with each other. The leaf spring  35  is shaped so as to not prevent flow of ink from the opening  277  to the foam  34 . 
     The foam  34  is a porous member that is arranged between the leaf spring  271  and a filter  273  of the container. The foam  34  supplies ink supplied from inside the liquid container  200  through the opening  277 , to the filter  36  of the cartridge in a diffused manner. The foam  34  is formed by synthetic resin such as polyethylene terephthalate. 
     The liquid supply port  281  is an area through which ink in the liquid container  200  flows to the outside of the cartridge  20 . Specifically, in the filter  36  of the cartridge, not the entire area of the filter, but an area AR that comes into contact with the filter  643  of the apparatus provided on the liquid introduction unit  640  of the holder  60  such that ink flows out is referred to as the liquid supply port  281 , in this embodiment. 
     As shown in  FIGS. 6 and 14 , the outer peripheral wall  288  that surrounds the liquid supply part  280  is provided on the first wall portion  201 . The outer peripheral wall  288  protrudes from the first wall portion  201  in the −Z axis direction. In the mounted state, an end portion  289  of the outer peripheral wall  288  in the −Z axis direction abuts on the sealing member  648  provided on the bottom wall portion  601  of the holder  60 . The outer peripheral wall  288  and the sealing member  648  abut on each other in this manner, and thereby the space inward of the outer peripheral wall  288  becomes a substantially closed space. Hereinafter, this space is referred to as a “closed space”. 
     In the first wall portion  201 , a communication port  32  is formed between the outer peripheral wall  288  and the liquid supply part  280 . The communication port  32  is an opening for allowing the closed space inward of the outer peripheral wall  288  to communicate with the exterior. In the mounted state, the communication port  32  allows the closed space inward of the outer peripheral wall  288  to communicate with the exterior (external air), and thereby the pressure difference between the closed space and the exterior is kept substantially constant. Therefore, leakage of ink from the liquid supply part  280  accompanying pressure fluctuation in the closed space is suppressed. 
       FIGS. 15 to 17  are schematic diagrams illustrating the internal structure of the cartridge  20 . As shown in  FIG. 15 , the outer shell  22  of the cartridge  20  includes a main body member  21  and a lid member  23 . The main body member  21  is constituted by the first wall portion  201 , the second wall portion  202 , the third wall portion  203 , the fourth wall portion  204 , the fifth wall portion  205  and the seventh wall portion  207 . The lid member  23  constitutes the sixth wall portion  206 . An internal space is formed in the cartridge  20  by attaching the lid member  23  so as to block the opening of the main body member  21 . The communication port  32  is provided in the main body member  21 . Also, the ventilation port  290  is provided in the lid member  23 . Both the communication port  32  and the ventilation port  290  communicate with the atmospheric air. A sheet member  291  serving as a flexible member is positioned between the fifth wall portion  205  and the sixth wall portion  206  (the lid member  23 ). 
     The cartridge  20  is provided with the liquid container  200 . The liquid container  200  is partitioned by the main body member  21  and the sheet member  291 . Accordingly, ink is contained between the fifth wall portion  205  of the main body member  21  and the sheet member  291 . The liquid container  200  communicates with the liquid supply part  280  via the opening  277 . The cartridge  20  is also provided with an air chamber  241 . The air chamber  241  is a space formed between the lid member  23  and the sheet member  291 . The air chamber  241  communicates with the external atmospheric air through the ventilation port  290  provided in the lid member  23 . Moreover, the communication port  32  communicates with the air chamber  241 . 
     A pressure receiving plate  293  as a plate-like member is arranged in the liquid container  200 . One face of the pressure receiving plate  293  is in contact with a face on the liquid container  200  side of the sheet member  291 . Also, in the liquid container  200 , a coil spring  294  serving as a biasing member is arranged between the other face (a face on the −Y axis direction side) of the pressure receiving plate  293  and the fifth wall portion  205 . The coil spring  294  biases the pressure receiving plate  293  from the fifth wall portion  205  toward the sixth wall portion  206 . Specifically, the coil spring  294  biases the sheet member  291  via the pressure receiving plate  293  in a direction in which the volume of the liquid container  200  is increased. The pressure in the liquid container  200  is maintained at a pressure lower than the atmospheric air pressure (negative pressure) due to this biasing force of the coil spring  294 . 
     In this embodiment, in planar view in a direction from the fifth wall portion  205  toward the sixth wall portion  206 , the coil spring  294  is a spring having a cylindrical shape such that the diameter of a portion of the coil spring  294  that is close to the fifth wall portion  205  and the diameter of a portion that is close to the sixth wall portion  206  are uniform. However, the shape of the coil spring  294  is not limited to such a shape, and the diameter of the portion close to the fifth wall portion  205  and the diameter of the portion close to the sixth wall portion  206  may be different. 
     The atmospheric air is introduced into the liquid container  200  via the ventilation port  290 , the air chamber  241  and an air introduction port  47  at a predetermined timing. The air introduction port  47  is a communication hole that allows the space (the liquid container  200 ) between the fifth wall portion  205  and the sheet member  291  to communicate with the space (the air chamber  241 ) between the sixth wall portion  206  and the sheet member  291 . The cartridge  20  is provided with an atmospheric air valve  40  for opening/closing this air introduction port  47 . The atmospheric air valve  40  is provided with a valve seat  46 , a valve member  44 , and a coil spring  42 . The valve member  44  is provided with a valve portion  43  and a lever portion  49 . The valve portion  43  abuts on the valve seat  46  and is separated from the valve seat  46 , thereby opening and closing the air introduction port  47 . The valve portion  43  of the valve member  44  is pressed against the valve seat  46  by the coil spring  42 , and blocks the air introduction port  47 , which is a through hole formed in the valve seat  46 . The valve portion  43  opens/closes the air introduction port  47 . The lever portion  49  abuts on the pressure receiving plate  293 , thereby moving the valve portion  43 . The lever portion  49  moves the valve portion  43 , thereby separating the valve portion  43  from the valve seat  46 , and opening the air introduction port  47 . 
     The operations of the cartridge  20  will be described below. In an initial state (non-usage state) of the cartridge  20 , the liquid container  200  is filled with ink. At this time, the pressure receiving plate  293  is at a position closest to the lid member  23 , as shown in  FIG. 15 . 
     As shown in  FIG. 16 , when ink in the liquid container  200  is consumed and the pressure receiving plate  293  approaches the fifth wall portion  205 , the pressure receiving plate  293  presses the lever portion  49  toward the fifth wall portion  205 . This separates the valve portion  43  from the air introduction port  47 . Accordingly, the valve member  44  enters an opened-valve state. The external air then flows into the liquid container  200  through the ventilation port  290 , the air chamber  241  and the air introduction port  47 . This increases the volume of the liquid container  200  by the amount of the introduced air as shown in  FIG. 17 . At the same time, the negative pressure in the liquid container  200  decreases and approaches the atmospheric air pressure. When a certain amount of air is introduced into the liquid container  200 , the pressure receiving plate  293  is separated from the lever portion  49 . Accordingly, the valve portion  43  blocks the air introduction port  47  again. In other words, the valve member  44  enters a closed-valve state. In this manner, when the negative pressure in the liquid container  200  increases in accordance with the consumption of ink in the liquid container  200 , the valve member  44  temporally enters an opened-valve state, and thereby it becomes possible to maintain the pressure in the liquid container  200  in a range of an appropriate pressure. Therefore, for example, it becomes possible to suppress excessive increase in negative pressure in the liquid container  200  and prevention of supply of ink from the liquid supply part  280 . 
       FIG. 18  is an exploded perspective view of the cartridge  20 . The cartridge  20  is provided with the main body member  21 , the lid member  23  having a plate-like shape, and the sheet member  291  having flexibility. The main body member  21  is substantially rectangular parallelepiped-shaped. The main body member  21  has an opening  222  on the +Y axis direction side and is recess-shaped. The sheet member  291  is adhered or welded to the main body member  21 , and the sheet member  291  and the main body member  21  define and form the liquid container  200 . Accordingly, a portion of the outer peripheral wall of the liquid container  200  is formed by the sheet member  291 . A through hole  292  that allows the air chamber  241  and the air introduction port  47  to communicate with each other is formed in the sheet member  291 . 
     The lid member  23  is attached to the main body member  21  so as to cover the sheet member  291 . The main body member  21  and the lid member  23  are formed by synthetic resin such as polypropylene. The sheet member  291  is formed by synthetic resin such as a material containing nylon and polypropylene. 
     The pressure receiving plate  293  is formed by synthetic resin such as polypropylene or metal such as stainless steel. The pressure receiving plate  293  is arranged so as to be in contact with the sheet member  291 . The coil spring  294  is arranged in the liquid container  200 . The coil spring  294  abuts on the pressure receiving plate  293  and a face opposing the pressure receiving plate  293  among the faces of the main body member  21 . The pressure receiving plate  293  moves in the liquid container  200  in accordance with the consumption of ink in the liquid container  200 . The direction of movement of the pressure receiving plate  293  is (a direction along) the Y axis direction. 
     The atmospheric air valve  40  is provided with the coil spring  42 , the valve member  44  and the valve seat  46 . The valve seat  46  is housed in a corner portion  240  of the main body member  21  in which the second wall portion  202  and the fourth wall portion  204  cross each other, and is attached to the main body member  21 . The valve seat  46  is formed by synthetic resin such as polypropylene. The valve seat  46  has a recess portion, and the sheet member  291  is airtightly adhered to an end face  41  that forms the opening of the recess portion. The recess portion of the valve seat  46  communicates with the through hole  292  of the sheet member  291 . Moreover, the air introduction port  47  that penetrates to the back side of the valve seat  46  is formed in the bottom portion of the recess portion of the valve seat  46 . 
     The valve member  44  is formed by synthetic resin such as polypropylene. The valve member  44  may be formed by two-color molding using an elastic member such as elastomer and synthetic resin such as polypropylene. 
     A sticker  25  may be adhered to the outer surface of the second wall portion  202  of the main body member  21 . The manufacturer and the model number of the cartridge  20  are indicated on the sticker  25 , for example. Note that the sticker  25  may be adhered at any position. For example, the sticker  25  may be adhered to any one of the second wall portion  202 , the third wall portion  203 , the fourth wall portion  204 , the fifth wall portion  205  and the sixth wall portion  206 , or may be adhered across two or more wall portions. Also, a plurality of stickers may be adhered on a plurality of wall portions. 
       FIG. 19  is an XZ cross-sectional view of the cartridge  20  and the carriage unit  520  in the mounted state. In  FIG. 19 , four reference planes RP 1  to RP 4  that are parallel in the Y axis direction are shown. In the mounted state, the first reference plane RP 1  is a plane including a face on which the end portion  289  of the outer peripheral wall  288  and the sealing member  648  abut on each other. The second reference plane RP 2  is a plane including the plurality of contact portions  16 . To be more specific, the second reference plane RP 2  is a plane including the two rows R 1  and R 2  ( FIG. 6 ) formed by the plurality of contact portions  16 . The third reference plane RP 3  is a plane including a face on the liquid container  200  side of the seventh wall portion  207 . The fourth reference plane RP 4  is a plane including a face on the substrate  15  side of the seventh wall portion  207 . 
     In the following description, a direction orthogonal to the first reference plane RP 1  is referred to as a Z axis direction. Also, a direction orthogonal to the Z axis direction is referred to as an X axis direction or a Y axis direction. The X axis direction, the Y axis direction, and the Z axis direction are orthogonal to each other. Also, the X axis direction is set to be a direction in which the carriage unit  520  moves in a state in which the cartridge  20  is mounted in the carriage unit  520 . Moreover, in the following description, the position of the positioning portion  30  is a position in a face on the −Z axis direction side of the first wall portion  201 , and unless particularly stated otherwise, the depth of a recess formed in the Z axis direction is not taken into consideration. 
     In this embodiment, in planar view of the cartridge  20  in the Z axis direction, the positioning portion  30  is positioned between the end portion  289  of the outer peripheral wall  288  and the plurality of contact portions  16  in the X axis direction. Also, in planar view of the cartridge  20  in the X axis direction, the positioning portion  30  is positioned between the end portion  289  of the outer peripheral wall  288  and the plurality of contact portions  16  in the Z axis direction. Furthermore, the second reference plane RP 2  crosses the sealing member  648 . According to such a configuration, the position of the positioning portion  30  can be brought close to both the liquid supply part  280  and the substrate  15 . Therefore, it is possible to increase both the accuracy of the contact position of the substrate  15  and the electrode part  61  and the accuracy of the contact position of the liquid supply part  280  and the liquid introduction unit  640 . In other words, it is possible to improve the accuracy of both the contact position of the liquid supply port  281  of the cartridge  20  with the printer  50  and the contact position of the contact portions  16  with the printer  50 . 
     Moreover, in this embodiment, in planar view in the Z axis direction, the positioning portion  30  is closer to one of the plurality of contact portions  16  than to the end portion  289  of the outer peripheral wall  288  in the X axis direction. In other words, in planar view in the Z axis direction, the shortest distance between the contact portion  16  that is closest to the positioning portion  30  among the plurality of contact portions  16  and the positioning portion  30  is shorter than the shortest distance between the end portion  289  of the outer peripheral wall  288  and the positioning portion  30  in the X axis direction. Furthermore, in planar view of the cartridge  20  in the X axis direction, the positioning portion  30  is closer to the end portion  289  of the outer peripheral wall  288  than to the plurality of contact portions  16  in the Z axis direction. In other words, in planar view in the X axis direction, the shortest distance between the end portion  289  of the outer peripheral wall  288  and the positioning portion  30  is shorter than the shortest distance between the plurality of contact portions  16  and the positioning portion  30  in the Z axis direction. Therefore, it is possible to improve the accuracy of both the contact position of the liquid supply port  281  of the cartridge  20  with the printer  50  and the contact position of the contact portions  16  of the cartridge  20  with the printer  50 . 
     Moreover, in this embodiment, in planar view of the cartridge  20  in the X axis direction, the positioning portion  30  is positioned between a face  211  of the first wall portion  201  that opposes the second wall portion  202  and the end portion  289  of the outer peripheral wall  288  in the Z axis direction. Therefore, the positioning portion  30  can be brought close to the liquid supply port  281 . Therefore, it is possible to improve the accuracy of the contact position of the liquid supply port  281  of the cartridge  20  with the printer  50 . 
     Moreover, in this embodiment, in planar view of the cartridge  20  in the Z axis direction, the positioning portion  30  is positioned between the seventh wall portion  207  and the end portion  289  of the outer peripheral wall  288  in the X axis direction. Therefore, the positioning portion  30  can be brought close to the liquid supply part  280 . Therefore, it is possible to improve the accuracy of the contact position of the liquid supply port  281  of the cartridge  20  with the printer  50 . 
     Moreover, in this embodiment, in planar view of the cartridge  20  in the X axis direction, the positioning portion  30  is positioned between the opening  277  and the end portion  289  of the outer peripheral wall  288  in the Z axis direction. Therefore, the positioning portion  30  can be brought close to the liquid supply part  280 . Therefore, it is possible to improve the accuracy of the contact position of the liquid supply port  281  of the cartridge  20  with the printer  50 . 
     Moreover, in this embodiment, the outer peripheral wall  288  and the positioning portion  30  are provided on the first wall portion  201 , and the third reference plane RP 3  crosses the liquid supply part  280 . Therefore, the position of the positioning portion  30  can be brought close to both the liquid supply part  280  and the substrate  15 . Therefore, it is possible to improve the accuracy of both the contact position of the liquid supply port  281  of the cartridge  20  with the printer  50  and the contact position of the contact portions  16  of the cartridge  20  with the printer  50 . 
     Moreover, in this embodiment, the outer peripheral wall  288  and the positioning portion  30  are provided on the first wall portion  201 , and the fourth reference plane RP 4  crosses the sealing member  648 . Therefore, the position of the positioning portion  30  can be brought close to both the liquid supply part  280  and the substrate  15 . Therefore, it is possible to improve the accuracy of both the contact position of the liquid supply port  281  of the cartridge  20  with the printer  50  and the contact position of the contact portions  16  of the cartridge  20  with the printer  50 . 
     Moreover, in this embodiment, in the mounted state, all of the heights h 2  to h 4 , from the first reference plane RP 1  in the Z axis direction, of positions P 2  to P 4  at which the respective reference planes RP 2  to RP 4  intersect the outer surface of the fourth wall portion  204  are less than or equal to half the height from the first reference plane RP 1  to the outer surface of the second wall portion  202 , namely, the maximum height MH of the cartridge  20 . To be more specific, the height h 2 , from the first reference plane RP 1 , of the position P 2  at which the second reference plane RP 2  intersects the outer surface of the fourth wall portion  204  is less than or equal to half the maximum height MH of the cartridge. Also, the height h 3  from the first reference plane RP 1  of the position P 3  at which the third reference plane RP 3  intersects the outer surface of the fourth wall portion  204  is less than or equal to half the maximum height MH of the cartridge. Moreover, the height h 4  from the first reference plane RP 1  of the position P 4  at which the fourth reference plane RP 4  intersects the outer surface of the fourth wall portion  204  is less than or equal to half the maximum height MH of the cartridge. According to such a configuration, the positioning portion  30  and the substrate  15  can be provided so as to be close to each other, and thus it is possible to increase the accuracy of the contact position of the substrate  15  and the electrode part  61 . Note that the rising angle (inclination angle) of each of the reference planes RP 2  to RP 4  from the first reference plane RP 1  is preferably 15 to 45°, and is more preferably 30 to 40°. 
     In this embodiment, by adopting the above-described configuration, the positions of the positioning portion  30  and the liquid supply part  280  can be brought close, and the positions of the positioning portion  30  and the contact portions  16  can be brought close. Accordingly, the positions of the liquid supply part  280  and the contact portions  16  can be brought close to each other. Therefore, the length of the cartridge  20  in the X axis direction can be reduced. Note that if the length of the cartridge  20  in the X axis direction is simply reduced, the volume of the liquid container  200  is reduced. In view of this, in order to ensure a volume, it is preferred to increase the length (height) of the cartridge  20  in the Z axis direction, or to increase the length (width) in the Y axis direction. In this embodiment, the cartridge  20  is arranged in a direction perpendicular to a direction (the X axis direction) in which the carriage unit  520  moves (see  FIG. 1 ), and thus even if the length of the cartridge  20  in the Y axis direction is increased, it is possible to suppress an increase in the size of the casing of the printer  50  in the direction of the movement of the carriage unit  520 . Moreover, in this embodiment, the length of the cartridge  20  in the Y axis direction can be increased, and thus it is possible to suppress an increase in the size of the cartridge  20  in the Z axis direction. Therefore, it is also possible to suppress an increase in the size of the casing of the printer  50  in the height direction. Therefore, according to this embodiment, the size of the printer  50  can be reduced. 
       FIG. 20  is an explanatory view showing an effect of the positioning portion  30 . A fifth reference plane RP 5  shown in  FIG. 20  is a plane parallel to the XY plane, and is a plane that passes through the end portion in the −Z axis direction of an internal face  31  that faces the −X axis direction side of the positioning portion  30 . A sixth reference plane RP 6  is a plane parallel to the XY plane, and is a plane that passes through the outer surface between the positioning portion  30  and the outer peripheral wall  288 . A seventh reference plane RP 7  is a plane that is parallel to the YZ plane, and is a plane that passes through the internal face  31  on the +X axis direction side of the positioning portion  30  in the mounted state. In this embodiment, the fifth reference plane RP 5  and the sixth reference plane RP 6  are different planes, because the positioning portion  30  has, at the end portion thereof in the −Z axis direction, an opening portion  33  that is directed in the +X axis direction. The opening portion  33  is used for guiding the projection  610  into the positioning portion  30  when the cartridge  20  is mounted to the holder  60 . 
     When the cartridge  20  is mounted to the printer  50 , the positioning portion  30  fits with the projection  610  provided on the holder  60 . The positioning portion  30  then abuts on at least a portion of the projection  610 . 
     In this embodiment, the projection  610  provided on the holder  60  may abut on the positioning portion  30  in all or any one of the directions indicated by 1 to 3 as follows. 
     1. a direction from the third wall portion  203  toward the fourth wall portion  204  (the +X axis direction). 
     2. a direction from the fifth wall portion  205  toward the sixth wall portion  206  (the +Y axis direction). 
     3. a direction from the sixth wall portion  206  toward the fifth wall portion  205  (the −Y axis direction). 
     In the case where a direction in which the projection  610  abuts on the positioning portion  30  is the direction 1, the positioning portion  30  is an intersection P 4  portion between the fifth reference plane RP 5  and the seventh reference plane RP 7  in  FIG. 20 , in a narrow sense. In  FIG. 20 , the intersection P 4  indicates a position that is in the abutting portion and is closest to the holder  60 . In other words, in the case where a direction in which the projection  610  abuts on the positioning portion  30  is the direction 1, the positioning portion  30  is positioned in the internal face  31  that forms the recess provided in the first wall portion  201 , and is directed on the −X axis direction side. 
     If the projection  610  abuts on the positioning portion  30  in the direction 1, it is possible to increase the position accuracy of the cartridge  20  in the depth direction (the +X axis direction). Also, the cartridge  20  is biased by the electrode part  61  of the holder  60  in the −X axis direction, and thus if the projection  610  abuts on the positioning portion  30  in the direction 1, it is possible to restrict the movement of the cartridge  20  in the −X axis direction. 
     In the case where a direction in which the projection  610  abuts on the positioning portion  30  is the direction 2 or 3, the positioning portion  30  is, in  FIG. 20 , a portion P 5  in which the fifth reference plane RP 5  and the projection  610  intersect, in a narrow sense. In  FIG. 20 , the intersection portion P 5  indicates a position that is in the abutting portion, and is closest to the holder  60 . In the case where a direction in which the projection  610  abuts on the positioning portion  30  is the direction 2, the positioning portion  30  is positioned in an internal face that forms the recess provided in the first wall portion  201 , and is directed on the −Y axis direction side. In the case where a direction in which the projection  610  abuts on the positioning portion  30  is the direction 3, the positioning portion  30  is positioned in an internal face that forms the recess provided in the first wall portion  201 , and is directed on the +Y axis direction side. 
     If the projection  610  abuts on the positioning portion  30  in the direction 2 or 3, it is possible to increase the position accuracy of the cartridge  20  in the width direction (the Y axis direction). 
     B. Variations 
     Variation 1 
     In the above embodiment, as long as each of the first wall portion  201  to the seventh wall portion  207  can constitute the cartridge  20 , the shapes of portions directed outward and the shapes of portions directed inward do not need to be flat, and a structure that includes recessions and protrusions may be adopted. For example, the first restriction portion  210  of the cartridge may be provided on or included in the fourth wall portion  204 , as a portion of recessions and protrusions of the fourth wall portion  204 . The second restriction portion  221  of the cartridge may be provided on or included in the third wall portion  203 , as a portion of recessions and protrusions of the third wall portion  203 . Also, the outer peripheral wall  288  that surrounds the liquid supply part  280  may be provided on or included in the first wall portion  201 , as a portion of recessions and protrusions of the first wall portion  201 . 
     Variation 2 
     In the above embodiment, as shown in  FIG. 12 , the distance LX between the third wall portion  203  and the fourth wall portion  204  that constitute the cartridge  20  is greater than the distance LY between the fifth wall portion  205  and the sixth wall portion  206 . However, the distance LX between the third wall portion  203  and the fourth wall portion  204  may be smaller than the distance LY between the fifth wall portion  205  and the sixth wall portion  206 . Moreover, in the above embodiment, when put in ascending order, the length (length in the X axis direction), the height (length in the Z axis direction) and the width (length in the Y axis direction) of the cartridge  20  are in the following order: length, height, width. However, the size relation of the length, the width and the height of the cartridge  20  can be arbitrarily changed, and for example, when put in ascending order, the order may be: height, length, width, or the height, the length and the width may be equal. 
     Variation 3 
     In the above embodiment, as shown in  FIG. 14 , the liquid supply part  280  is provided with the foam  34  and the leaf spring  35 . However, as long as ink can be supplied from the liquid container  200  to the liquid introduction unit  640  of the printer  50 , the liquid supply part  280  may have any structure. For example, either the foam  34  or the leaf spring  35  may be omitted. Moreover, all of or some of the filter  36  of the cartridge, the foam  34  and the leaf spring  35  may be replaced by foam. 
     Variation 4 
     In the above embodiment, the cartridge  20  satisfies a first condition that the second reference plane RP 2  crosses the sealing member  648 , a second condition that the third reference plane RP 3  crosses the liquid supply part  280 , and a third condition that the fourth reference plane RP 4  crosses the sealing member  648 . However, the cartridge  20  does not need to satisfy all of these conditions. For example, it suffices for the cartridge  20  to satisfy only one condition, or to satisfy two conditions. 
     Variation 5 
     In the above embodiment, a plurality of cartridges  20  are arranged in a direction perpendicular to the direction of the movement of the carriage unit  520  and are mounted to the holder  60 . However, a plurality of cartridges  20  may be arranged in the direction of the movement of the carriage unit  520  and be mounted to the holder  60 . 
     Variation 6 
     In the above embodiment, in planar view of the cartridge  20  in the Z axis direction, the positioning portion  30  is closer to any one of the plurality of contact portions  16  than the end portion  289  of the outer peripheral wall  288  in the X axis direction. However, the positioning portion  30  may be closer to the end portion  289  of the outer peripheral wall  288  than the plurality of contact portions  16 . 
     Variation 7 
     In the above embodiment, in planar view of the cartridge  20  in the X axis direction, the positioning portion  30  is closer to the end portion  289  of the outer peripheral wall  288  than the plurality of contact portions  16  in the Z axis direction. However, the positioning portion  30  may be closer to the plurality of contact portions  16  than the end portion  289  of the outer peripheral wall  288 . 
     Variation 8 
     In the above embodiment, the cartridge  20  is constituted by seven wall portions. However, as long as a space that can contain ink is formed, the number of wall portions that constitute the cartridge  20  is not limited to seven. For example, the cartridge  20  may be constituted by six or fewer wall portions, or may be constituted by eight or more wall portions. Moreover, for example, the cartridge  20  may be constituted by one or more wall portions that are spherical or curved. Alternatively, the cartridge  20  may be constituted by a combination of curved wall portions and plate-like wall portions. 
     Variation 9 
     In the above embodiment, in planar view of the cartridge  20  in the X axis direction, the positioning portion  30  is positioned between the face  211  of the first wall portion  201  that opposes the second wall portion  202  and the end portion  289  of the outer peripheral wall  288  in the Z axis direction. However, the positioning portion  30  may be positioned on the +Z axis direction side relative to the face  211  of the first wall portion  201  that opposes the second wall portion  202 . The positioning portion  30  may also be positioned on the −Z axis direction side relative to the end portion  289  of the outer peripheral wall  288 . 
     Variation 10 
     In the above embodiment, in planar view of the cartridge  20  in the Z axis direction, the positioning portion  30  is positioned between the seventh wall portion  207  and the end portion  289  of the outer peripheral wall  288  in the X axis direction. However, the positioning portion  30  may be positioned on the seventh wall portion  207 , for example. 
     Variation 11 
     In the above embodiment, in planar view of the cartridge  20  in the X axis direction, the positioning portion  30  is positioned between the opening  277  and the end portion  289  of the outer peripheral wall  288  in the Z axis direction. However, the positioning portion  30  may be positioned on the +Z axis direction side relative to the opening  277 . The positioning portion  30  may also be positioned on the −Z axis direction side relative to the end portion  289  of the outer peripheral wall  288 . 
     Variation 12 
     The present invention is not limited to an inkjet printer and an ink cartridge thereof, and can also be applied to any liquid ejection apparatus that consumes liquid other than ink and a cartridge (liquid supply unit) used for such a liquid ejection apparatus. For example, the present invention can be applied as a cartridge used for various liquid ejection apparatuses as follows: 
     (1) an image recording apparatus such as a facsimile apparatus, 
     (2) a color material ejection apparatus used for manufacturing color filters for an image display device such as a liquid crystal display, 
     (3) an electrode material ejection apparatus used for forming electrodes for an organic EL (Electro Luminescence) display, an FED (Field Emission Display) and the like, 
     (4) a liquid ejection apparatus for ejecting a liquid containing biological organic matter used for manufacturing biochips, 
     (5) a sample ejection apparatus serving as a precision pipette, 
     (6) a lubricant ejection apparatus, 
     (7) a resin liquid ejection apparatus, 
     (8) a liquid ejection apparatus for ejecting a lubricant at pinpoint for a precision device such as a timepiece and a camera, 
     (9) a liquid ejection apparatus for ejecting a transparent resin liquid such as an ultraviolet-curing resin liquid onto a substrate in order to form, for example, a hemispherical micro lens (optical lens) used in an optical communication element or the like,
 
(10) a liquid ejection apparatus for ejecting an acid or alkali etching solution in order to etch a substrate or the like, and
 
(11) a liquid ejection apparatus provided with a liquid consumption head for discharging a minute amount of any other liquid droplets.
 
     Note that “liquid droplets” refer to a state of a liquid that is discharged from a liquid ejection apparatus, and includes a liquid that leaves a trail in the form of particles, tears, or threads. It suffices for the “liquid” as referred to herein to be such a material that can be consumed by a liquid ejection apparatus. For example, it suffices for the “liquid” to be a material in a state in which the substance is in the liquid phase, and the “liquid” includes materials in a liquid state such as high- or low-viscosity liquids, and materials in a liquid state such as sols, gel waters, other inorganic solvents, organic solvents, solutions, liquid resins, and liquid metals (molten metals). The “liquid” includes not only liquids in the form of one state of a substance, but also solvents into which particles of a functional material composed of a solid matter such as a pigment or metal particles has been dissolved, dispersed or mixed, and the like. Representative examples of liquids include not only ink, such as was described in the above embodiment, but also liquid crystal and the like. Herein, the term “ink” encompasses a variety of compositions in the form of a liquid, such as general water-soluble inks and oil-soluble inks as well as gel inks, hot melt inks, and the like. 
     The invention is not limited to the above embodiment and variations, and can be achieved as various configurations without departing from the gist of the invention. For example, the technical features in the embodiment and variations that correspond to the technical features in the aspects described in the summary of the invention may be replaced or combined as appropriate in order to solve a part of, or the entire foregoing problem, or to achieve some or all of the above-described effects. The technical features that are not described as essential in the specification may be deleted as appropriate.