Patent Publication Number: US-9849685-B2

Title: Liquid supply device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority from Japanese patent application 2014-051911 filed on Mar. 14, 2014, the content of which is hereby incorporated by reference into this application. 
     TECHNICAL FIELD 
     The present disclosure relates to technology with regard to a liquid supply device configured to supply a liquid to a liquid consuming apparatus. 
     BACKGROUND ART 
     An external ink supply device configured to supply ink from outside of a printer has been known as a technique of supplying ink to the printer as a liquid consuming apparatus (for example, Patent Literature 1). 
     CITATION LIST 
     Patent Literature 
     PTL 1: JP 2009-202346A 
     SUMMARY 
     Technical Problem 
     According to the technique described in above Patent Literature 1, the external ink supply device includes an ink bag configured to contain ink, a connection structure (liquid lead-out portion) configured to flow out ink from the ink bag, and an ink supply tube (liquid introduction portion) configured to supply the ink flowed out through the connection structure to the printer. In this external ink supply device, the connection structure is located below the ink bag in the vertical direction. This configuration may provide a difficulty in observing the connection structure for the ink bag, for example, at the time of replacement of the ink bag. There is accordingly a problem of difficulty in attaching and detaching the liquid introduction portion to and from the liquid lead-out portion. 
     This problem is not characteristic of the ink supply device configured to supply ink to the printer but is commonly found in any liquid supply device configured to supply a liquid to a liquid consuming apparatus. 
     A first object of the disclosure is accordingly to provide a technique of readily connecting the liquid lead-out portion with the liquid introduction portion. A second object of the disclosure is to provide a technique of ensuring favorable connection between the liquid lead-out portion and the liquid introduction portion. Other needs include, for example, cost reduction, resource saving, easy manufacture and improvement of usability over the prior art. 
     Solution to Problem 
     In order to solve at least one of the problems described above, the disclosure may be implemented by aspects described below. 
     (1) According to one aspect of the disclosure, there is provided a liquid supply device configured to supply a liquid to a liquid consuming apparatus. This liquid supply device comprises a liquid container configured to include a liquid supply portion and to contain the liquid therein; and a liquid supply connection structure supported on an outer wall of the liquid consuming apparatus and connected with the liquid supply portion. 
     In the liquid supply device of this aspect, the liquid supply connection structure is supported on the outer wall. This configuration facilitates connection of the liquid container with the liquid supply connection structure. This configuration also provides a larger space for the liquid container placed therein, compared with the configuration that the liquid supply connection structure is placed inside of the liquid consuming apparatus. This accordingly allows a large amount of liquid to be contained in the liquid container. This configuration also shortens the flow path of the liquid from the liquid container to the liquid consuming apparatus (liquid supply passage), compared with the external configuration that the liquid container is placed at a location away from the liquid consuming apparatus. This accordingly shortens a time period required for the liquid contained in the liquid container to reach the liquid consuming apparatus through the liquid supply passage after formation of the liquid supply passage by connection of the liquid supply portion of the liquid container with the liquid supply connection structure. This also suppresses a component of the liquid from being vaporized through the liquid supply passage to change the properties of the liquid. 
     (2) The liquid supply device of the above aspect may further comprise a protective member arranged to cover at least an upper portion of the liquid supply connection structure. 
     In the liquid supply device of this aspect, the presence of the protective member reduces the possibility that any extraneous substance such as dust adheres to the liquid supply connection structure. This configuration accordingly reduces the possibility that any extraneous substance is included in the liquid supplied from the liquid container to the liquid consuming apparatus. 
     (3) In the liquid supply device of the above aspect, the liquid container may have a container-side electrical connection structure. The liquid supply device may further comprise an apparatus-side electrical connection structure supported on the outer wall and connected with the container-side electrical connection structure. 
     In the liquid supply device of this aspect, the apparatus-side electrical connection structure is supported on the outer wall of the liquid consuming apparatus. This configuration facilitates connection of the container-side electrical connection structure with the apparatus-side electrical connection structure. 
     (4) In the liquid supply device of the above aspect, the protective member may be arranged to cover at least an upper portion of the apparatus-side electrical connection structure. 
     In the liquid supply device of this aspect, the presence of the protective member reduces the possibility that any extraneous substance such as dust adheres to the apparatus-side electrical connection structure. The presence of the protective member also reduces the likelihood that the user directly touches the liquid supply connection structure. Accordingly this configuration reduces a failure in connection between the container-side electrical connection structure and the apparatus-side electrical connection structure. 
     (5) In the liquid supply device of the above aspect, the liquid supply connection structure and the apparatus-side electrical connection structure may be arranged adjacent to each other. 
     The liquid supply device of this aspect enables the user to observe the liquid supply connection structure and the apparatus-side electrical connection structure and connect the corresponding portions of the liquid container. 
     (6) In the liquid supply device of the above aspect, the outer wall may comprise at least one of a first side wall that forms a first side face relative to a front face of the liquid consuming apparatus and a second side wall that forms a second side face relative to the front face. The liquid supply connection structure and the apparatus-side electrical connection structure may be arranged at positions respectively visible from the front face. 
     In the liquid supply device of this aspect, the liquid supply connection structure and the apparatus-side electrical connection structure are visible when the liquid consuming apparatus is viewed from the front face. This enables the position of connection of the liquid container to be readily recognized. 
     (7) In the liquid supply device of the above aspect, the liquid supply connection structure and the apparatus-side electrical connection structure may be arranged side by side in a predetermined direction. The outer wall may comprise at least one of a first side wall that forms a first side face relative to a front face of the liquid consuming apparatus and a second side wall that forms a second side face relative to the front face. The first side wall is a right side wall and the second side wall is a left side wall. When the liquid supply connection structure and the apparatus-side electrical connection structure are supported on the right side wall, an angle a1 between the right side wall and the predetermined direction may be greater than 0 degree and smaller than 90 degrees in a clockwise direction from the right side wall in a vertically downward view of the liquid consuming apparatus. When the liquid supply connection structure and the apparatus-side electrical connection structure are supported on the left side wall, an angle a2 between the left side wall and the predetermined direction may be greater than 0 degree and smaller than 90 degrees in a counterclockwise direction from the left side wall in the vertically downward view of the liquid consuming apparatus. 
     In the liquid supply device of this aspect, the angle a1 or the angle a2 is greater than 0 degree and is smaller than 90 degrees. This configuration suppresses expansion of the width in the left-side direction that is the direction in which the first side wall and the second side wall are opposed to each other. 
     (8) In the liquid supply device of the above aspect, in the vertically downward view of the liquid consuming apparatus, multiple sets of the liquid supply connection structures and the apparatus-side electrical connection structures may be arranged on one wall out of the right side wall and the left side wall at the angle a1 or at the angle a2 in a direction in which the front face and a rear face of the liquid consuming apparatus are opposed to each other. The liquid supply connection structure and the apparatus-side electrical connection structure may be provided on the other wall out of the right side wall and the left side wall to be arranged side by side along a direction parallel to the other wall. The liquid container connected with the liquid supply connection structure and the apparatus-side electrical connection structure supported on the other wall may have a larger capacity than capacities of the liquid containers connected with the multiple sets of the liquid supply connection structures and the apparatus-side electrical connection structures supported on the one wall. 
     In the liquid supply device of this aspect, the liquid container having the larger capacity is arranged parallel to the side wall. This configuration provides substantially equal spaces for mounting the liquid containers formed on the first side wall-side and on the second side-wall side across the liquid consuming apparatus. 
     (9) The liquid supply device of the above aspect may further comprise a liquid container holder attached to the outer wall and configured to place the liquid container therein. The liquid container holder may have a bottom face and an openable and closable top. 
     The liquid supply device of this aspect includes the liquid container holder having the bottom face. Even if the liquid is leaked out from the liquid supply connection structure during attachment or detaching of the liquid supply portion to the liquid supply connection structure, this configuration reduces the possibility that the outside of the liquid supply device is stained with the liquid. The top of the liquid container holder is configured to be openable and closable and may thus be opened and closed only when needed. This reduces the possibility that the liquid container is damaged. 
     All the plurality of components included in each of the aspects of the disclosure described above are not essential, but some components among the plurality of components may be appropriately changed, omitted or replaced with other additional components or part of the limitations may be deleted, in order to solve part or all of the problems described above or in order to achieve part or all of the advantageous effects described herein. In order to solve part or all of the problems described above or in order to achieve part or all of the advantageous effects described herein, part or all of the technical features included in one aspect of the disclosure described above may be combined with part or all of the technical features included in another aspect of the disclosure described above to provide one independent aspect of the disclosure. 
     For example, one aspect of the disclosure may be implemented as an apparatus comprising one or more elements out of a plurality of elements, i.e., a liquid container and a liquid supply connection structure. Accordingly this apparatus may include a liquid container or may not include the liquid container. This apparatus may include a liquid supply connection structure or may not include the liquid supply connection structure. This aspect solves at least one of various problems, such as downsizing of the apparatus, cost reduction, resource saving, easy manufacture and improvement of usability. Part or all of the technical features in each of the aspects of the liquid container described above may be applied to this apparatus. 
     The disclosure may be implemented by any of various aspects other than the liquid container, for example, a method of manufacturing the liquid container and a liquid consumption system including the liquid container and a liquid consuming apparatus. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a first perspective view illustrating the schematic configuration of a liquid consumption system; 
         FIG. 2  is a second perspective view illustrating the schematic configuration of the liquid consumption system; 
         FIG. 3  is a first diagram illustrating a liquid supply device; 
         FIG. 4  is a second diagram illustrating the liquid supply device; 
         FIG. 5A  is a third diagram illustrating the liquid supply device; 
         FIG. 5B  is a front view illustrating a mounting/demounting unit; 
         FIG. 5C  is a diagram illustrating a first state in which a movable member is protruded outward relative to a stationary member; 
         FIG. 6A  is a diagram illustrating a second state in which the movable member is placed in the stationary member; 
         FIG. 6B  is a first perspective view illustrating the movable member; 
         FIG. 6C  is a second perspective view illustrating the movable member; 
         FIG. 6D  is a third perspective view illustrating the movable member; 
         FIG. 6E  is a perspective view illustrating the mounting/demounting unit; 
         FIG. 6F  is an exploded perspective view illustrating the mounting/demounting unit; 
         FIG. 6G  is an F 5 Ba-F 5 Ba sectional view of  FIG. 5B ; 
         FIG. 6H  is a perspective view illustrating part of the mounting/demounting unit; 
         FIG. 6I  is a top view illustrating the mounting/demounting unit; 
         FIG. 6J  is an F 6 I-F 6 I sectional view of  FIG. 6I ; 
         FIG. 6K  is a partial enlarged view of an area R 6 J in  FIG. 6J ; 
         FIG. 6L  is a perspective view illustrating the state that a contact mechanism is mounted to the stationary member; 
         FIG. 6M  is a perspective view illustrating the stationary member; 
         FIG. 6N  is a front view illustrating the mounting/demounting unit; 
         FIG. 6O  is an F 6 N-F 6 N sectional view of  FIG. 6N ; 
         FIG. 6P  is a perspective view illustrating the contact mechanism; 
         FIG. 6Q  is a perspective view illustrating the contact mechanism; 
         FIG. 6R  is a rear view of  FIG. 6E ; 
         FIG. 6S  is a perspective view of  FIG. 6R ; 
         FIG. 6T  is a perspective view illustrating the contact mechanism; 
         FIG. 6U  is an enlarged view illustrating an apparatus-side board positioning structure of the contact mechanism; 
         FIG. 6V  is a perspective view illustrating an electrical connection structure; 
         FIG. 7  is a first perspective view illustrating a liquid container; 
         FIG. 8  is a second perspective view illustrating the liquid container; 
         FIG. 9  is a first perspective view illustrating part of the liquid container; 
         FIG. 10  is a second perspective view illustrating part of the liquid container; 
         FIG. 11  is a third perspective view illustrating part of the liquid container; 
         FIG. 12  is a fourth perspective view illustrating part of the liquid container; 
         FIG. 13  is a front view illustrating part of the liquid container; 
         FIG. 14  is a rear view illustrating part of the liquid container: 
         FIG. 15  is a top view illustrating part of the liquid container; 
         FIG. 16  is a right side view illustrating part of the liquid container; 
         FIG. 17A  is an F 13 -F 13  sectional view of  FIG. 13 ; 
         FIG. 17B  is a front view illustrating a circuit board; 
         FIG. 17C  is a view from an arrow F 17 B in  FIG. 17B ; 
         FIG. 17D  is an F 13   a -F 13   a  partial sectional view of  FIG. 13 ; 
         FIG. 17E  is a perspective view illustrating a groove; 
         FIG. 17F  is a perspective view illustrating a groove; 
         FIG. 18  is a diagram illustrating the state that the liquid container is set in the mounting/demounting unit; 
         FIG. 19  is an F 18 -F 18  partial sectional view of  FIG. 18 ; 
         FIG. 20  is a diagram illustrating the state that the liquid container is mounted to the mounting/demounting unit; 
         FIG. 21  is an F 20 -F 20  partial sectional view of  FIG. 20 ; 
         FIG. 22  is a first diagram illustrating connection timing; 
         FIG. 23  is an F 22 A-F 22 A partial sectional view of  FIG. 22 ; 
         FIG. 24  is an F 22 B-F 22 B partial sectional view of  FIG. 22 ; 
         FIG. 25  is a second diagram illustrating connection timing; 
         FIG. 26  is an F 25 A-F 25 A partial sectional view of  FIG. 25 ; 
         FIG. 27  is an F 25 B-F 25 B partial sectional view of  FIG. 25 ; 
         FIG. 28  is a side view illustrating the state that the liquid container is set in the movable member; 
         FIG. 29  is a front view illustrating the state that the liquid container is set in the movable member; 
         FIG. 30  is an F 28 -F 28  sectional view of  FIG. 28 ; 
         FIG. 31  is an F 29 -F 29  sectional view of  FIG. 29 ; 
         FIG. 32  is a side view illustrating the state that mounting of the liquid container to the mounting/demounting unit is completed; 
         FIG. 33  is an F 32 -F 32  sectional view of  FIG. 32 ; 
         FIG. 34  is an F 25 A-F 25 A partial enlarged view of  FIG. 25 ; 
         FIG. 35  is a diagram illustrating positioning; 
         FIG. 36  is an F 5 B-F 5 B partial sectional view of  FIG. 5B ; 
         FIG. 37  is a diagram illustrating a liquid introduction portion viewed from a −K2-axis direction side; 
         FIG. 38  is a top view illustrating the mounting/demounting unit; 
         FIG. 39  is an F 38 -F 38  sectional view; 
         FIG. 40  is a diagram illustrating a displacement mechanism; 
         FIG. 41  is a top view illustrating the mounting/demounting unit and the liquid container; 
         FIG. 42  is a first diagram corresponding to an F 41 -F 41  partial sectional view; 
         FIG. 43  is a second diagram corresponding to the F 41 -F 41  partial sectional view; 
         FIG. 44  is a third view corresponding to the F 41 -F 41  partial sectional view; 
         FIG. 45  is a diagram illustrating a preferable embodiment; 
         FIG. 46  is a diagram illustrating an example of preferable arrangement according to the embodiment; and 
         FIG. 47  is a diagram illustrating an electrical connector. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     A. Embodiment 
     A-1. Configuration of Liquid Consumption System: 
       FIG. 1  is a first perspective view illustrating the schematic configuration of a liquid consumption system  1000 .  FIG. 2  is a second perspective view illustrating the schematic configuration of the liquid consumption system  1000 .  FIG. 3  is a first diagram illustrating a liquid supply device  20 .  FIG. 4  is a second diagram illustrating the liquid supply device  20 .  FIG. 5A  is a third diagram illustrating the liquid supply device  20 .  FIG. 3  and  FIG. 4  illustrate the state that liquid containers  50  described later are demounted.  FIG. 5A  illustrates the state that one liquid container  50  is mounted. XYZ axes that are orthogonal to one another are illustrated in  FIGS. 1 to 5A . 
     As shown in  FIG. 1 , the liquid consumption system  1000  includes a printer  10  as a liquid consuming apparatus and two liquid supply devices  20 . In the use state of the liquid consumption system  1000 , the printer  10  is placed on a horizontal plane defined by an X-axis direction and a Y-axis direction. Accordingly a Z-axis direction is defined as vertical direction (direction of gravity, top-bottom direction); −Z-axis direction is defined as vertically downward and +Z-axis direction is defined as vertically upward. The liquid supply device  20  is configured to supply ink as a liquid to the printer  10 . A liquid container  50  (liquid container unit  50 ) included in the liquid supply device  20  is detachably connected with (mounted to) the printer  10 . 
     The printer  10  is an inkjet printer. The printer  10  includes a recording mechanism  11 , paper feed trays  16  and a paper eject tray  17 . A plurality of the paper feed trays  16  are provided at positions of different heights in the vertical direction. The paper feed trays  16  are provided on an apparatus first surface (apparatus front face, front face)  102  as the front face of the printer  10 . Recording media (for example, sheets of paper) on which images such as letters and characters are printed (recorded) by the printer  10  are placed in the paper feed trays  16 . 
     The recording mechanism  11  includes a record head (not shown) configured to eject ink. The record head is connected with the liquid supply devices  20  through flow pipes such as tubes. The record head uses and ejects ink supplied from the liquid supply device  20  on the recording medium to perform recording (printing). The recording medium after recording is discharged to the paper eject tray  17 . 
     Each of the two liquid supply devices  20  supplies ink to the printer  10  via a liquid introduction portion  362 . The two liquid supply devices  20  are respectively provided on an apparatus second surface (also called apparatus first side face or apparatus first side wall)  104  and an apparatus third surface (also called apparatus second side face or apparatus second side wall)  106  that are arranged to intersect with the apparatus first surface (also called apparatus front face or apparatus front wall)  102  of the printer  10 . The apparatus first surface  102  to the apparatus third surface  106  are respectively surfaces approximately perpendicular to the installation plane of the printer  10  in the use state of the printer  10 . The apparatus second surface  104  and the apparatus third surface  106  are opposed to each other. The liquid supply device  20  provided on the apparatus second surface  104  is also called first liquid supply device  20 A, and the liquid supply device  20  provided on the apparatus third surface  106  is also called second liquid supply device  20 B. When there is no need to distinguish between the first and the second liquid supply devices  20 A and  20 B, these are simply called liquid supply devices  20 . 
     As shown in  FIG. 1 , the first liquid supply device  20 A includes one cover member  22  as a liquid container holder, one liquid container  50  and one mounting/demounting unit  30  (shown in  FIG. 3 ). As shown in  FIG. 2 , the second liquid supply device  20 B includes one cover member  22 B as a liquid container holder, three liquid containers  50  and three mounting/demounting units  30  (shown in  FIG. 4 ) provided corresponding to the respective liquid containers  50 . In the description below, when there is a need to distinguish between the two cover members  22 , these are expressed by reference signs “ 22 A” and “ 22 B”. When there is a need to distinguish among the four liquid containers  50 , these are expressed by reference signs “ 50 K”, “ 50 C”, “ 50 M” and “ 50 Y”. When there is a need to distinguish among the four mounting/demounting units  30 , these are expressed by reference signs “ 30 K”, “ 30 C”, “ 30 M” and “ 30 Y”. The numbers of the cover members  22 , the liquid containers  50  and the mounting/demounting units  30  are not limited to those described above. For example, the number of the liquid containers  50  may be three or less or may be five or more. The number of the mounting/demounting units  30  may be determined corresponding to the number of the liquid containers  50 . The number of the cover members  22  may be one or may be three or more. The mounting/demounting unit  30  may be regarded as a component of the liquid supply device  20  or may be regarded as a component of the printer  10 . 
     The four liquid containers  50  respectively contain (are filled with) different types of inks. According to this embodiment, yellow (Y), magenta (M), cyan (C) and black (K) inks are respectively contained in the different liquid containers  50 . The liquid container  50 K includes a liquid container body configured to contain black ink. The liquid container  50 C includes a liquid container body configured to contain cyan ink. The liquid container  50 M includes a liquid container body configured to contain magenta ink. The liquid container  50 Y includes a liquid container body configured to contain yellow ink. As shown in  FIGS. 3 and 4 , the liquid containers  50  are placed in housing spaces  26  defined by the cover members  22  to place the liquid containers  50  therein. More specifically, the liquid container  50 K is placed in a housing space  26 A (shown in  FIG. 3 ), and the liquid containers  50 C,  50 M and  50 Y are placed in a housing space  26 B (shown in  FIG. 4 ). The mounting/demounting units  30  are also placed in the housing spaces  26 . 
     The liquid container  50  is detachably mounted to the mounting/demounting unit  30  shown in  FIGS. 3 and 4 . The mounting/demounting unit  30 K is placed inside of the cover member  22 A. The mounting/demounting units  30 C,  30 M and  30 Y are placed inside of the cover member  22 B. As shown in  FIG. 3 , the mounting/demounting unit  30 K is provided on the apparatus second surface  104  of the printer  10 . As shown in  FIG. 4 , the mounting/demounting units  30 C,  30 M and  30 Y are provided on the apparatus third surface  106  of the printer  10 . When the liquid container  50  is mounted to the mounting/demounting unit  30 , the ink contained in the liquid container  50  is supplied to the record head of the printer  10  by means of a supply mechanism (not shown) with pump function of the printer  10 . 
     As shown in  FIG. 3 , the cover member  22 A is attached to the apparatus second surface  104  as the outer wall of the printer  10 . As shown in  FIG. 4 , the cover member  22 B is attached to the apparatus third surface  105  as the outer wall of the printer  10 . As shown in  FIGS. 3 and 4 , the cover member  22  is configured to be openable and closable by rotating the other end portion (top)  24  on the vertically upper side about one end portion (bottom)  23  on the vertically lower side as the support point. After consumption of ink contained in the liquid container  50 , the user opens the cover member  22  and demounts the used liquid container  50  from the mounting/demounting unit  30 . The user then mounts a new liquid container  50  to the mounting/demounting unit  30  and subsequently closes the cover member  22 . 
     As shown in  FIG. 5A , the cover member  22  has a bottom face  27  that forms the bottom of the housing space  26 . The bottom face  27  is located below the mounting/demounting unit  30  in the direction of gravity. The bottom face  27  is a portion which the bottom of the liquid container  50  (or more specifically the bottom of a liquid container body  52 ) comes into contact with. A projection may be provided on the bottom face  27 , such that the bottom of the liquid container  50  comes into contact with the projection. 
     As illustrated with regard to the mounting/demounting unit  30 Y, the mounting/demounting unit  30  includes a liquid introduction portion  362  as a liquid supply connection structure and an electrical connection structure (supply-side electrical connection structure or an apparatus-side electrical connection structure)  382 . A liquid supply portion  57  (shown in  FIG. 9 ) of the liquid container  50  is connected with the liquid introduction portion  362 . Ink contained in the liquid container  50  flows through the liquid supply portion  57  to the liquid introduction portion  362 . The ink flowing to the liquid introduction portion  362  then flows to the record head of the recording mechanism  11  (shown in  FIG. 1 ). A circuit board  582  (shown in  FIG. 9 ) as a container-side electrical connection structure comes into contact with and is thereby electrically connected with the electrical connection structure  382 . The liquid introduction portion  362  and the electrical connection structure  382  are arranged side by side along a K2-axis direction. The K2-axis direction is a direction that is orthogonal to the Z-axis direction and is parallel to a plane (horizontal plane) defined by the X-axis direction and the Y-axis direction. A substrate unit  58  described later may be regarded as the container-side electrical connection structure. 
     As shown in  FIG. 5A , the liquid introduction portion  362  and the electrical connection structure  382  are respectively arranged at positions visible from the apparatus first surface  102 . More specifically, the K2-axis direction in which the liquid introduction portion  362  and the electrical connection structure  382  are arranged side by side intersects with the direction perpendicular to the apparatus first surface  102  (X-axis direction) at an angle a that is larger than zero degree and is not greater than 90 degrees. This angle a is an angle formed counterclockwise from the K2 axis to the X axis when the liquid supply device  20  is placed on the apparatus third surface  106  (shown in  FIG. 2 ) that is located on the right side of the apparatus first surface  102 . This angle a is also an angle formed clockwise from the K2 axis to the X axis when the liquid supply device  20  is placed on the apparatus second surface  104  (shown in  FIG. 1 ) that is located on the left side of the apparatus first surface  102 . In other words, one of the liquid introduction portion  362  and the electrical connection structure  382  placed on a side nearer to the apparatus first surface  102  (for example, the liquid introduction portion  362 ) is located on the outer side (for example, +Y-axis direction side) of the outer wall (for example, the apparatus third surface  106 ) where the respective components  362  and  382  are supported, compared with the other placed on a side farther from the apparatus first surface  102  (for example, the electrical connection structure  382 ). 
     When the printer  10  is viewed from the apparatus first surface  102 , this configuration enables the user to observe the liquid introduction portion  362  and the electrical connection structure  382 . The user can thus readily recognize the position of connection where the liquid container  50  is connected with the mounting/demounting unit  30 . This angle a is preferably between 15 degrees and 60 degrees inclusive and is more preferably between 20 degrees and 50 degrees inclusive. This configuration enables the position of connection to be readily recognized and suppresses expansion of the housing space  26  in the Y-axis direction. This accordingly allows the capacity of the housing space  26  to be efficiently utilized for placing the mounting/demounting unit  30  therein. 
     The first liquid supply device  20 A (shown in  FIG. 3 ) which the liquid container  50 K containing black ink is mounted in may have the angle a equal to zero degree. The second liquid supply device  20 B (shown in  FIG. 4 ) which the liquid containers  50 C,  50 M and  50 Y containing yellow and other color inks are mounted in may have the angle a satisfying the above range (greater than zero degree and not greater than 90 degrees). In other words, the direction in which the liquid introduction portion  362  and the electrical connection structure  382  of the first liquid supply device  20 A are arranged side by side may be parallel to the outer wall (for example, the apparatus second surface  104  shown in  FIG. 1 ). The liquid container  50 K containing black ink is generally filled with a greater amount of ink, compared with the other liquid containers  50 C,  50 M and  50 Y containing color inks. Accordingly the liquid container  50 K has the larger outer shape than the other liquid containers  50 C,  50 M and  50 Y. The respective components of the liquid container  50 K provided corresponding to the liquid introduction portion  362  and the electrical connection structure  382  of the first liquid supply device  20 A are, however, also arranged parallel to the apparatus second surface  104 . This configuration suppresses the outer shape of the first liquid supply device  20 A from being significantly different from the second outer shape of the second liquid supply device  20 B. 
     A-2. General Configuration of Mounting/Demounting Unit  30 : 
       FIG. 5B  is a front view illustrating the mounting/demounting unit  30 .  FIG. 5C  is a first perspective view illustrating the mounting/demounting unit  30 .  FIG. 6A  is a second perspective view illustrating the mounting/demounting unit  30 .  FIG. 5C  illustrates a first state (set state) in which a movable member  40  is protruded outward relative to a stationary member  35 .  FIG. 6A  illustrates a second state (mounted state) in which the movable member  40  is placed in the stationary member  35 .  FIG. 6B  is a first perspective view illustrating the movable member  40 .  FIG. 6C  is a second perspective view illustrating the movable member  40 .  FIG. 6D  is a third perspective view illustrating the movable member  40 . The configuration is described with regard to the mounting/demounting unit  30 C as an example with reference to  FIGS. 5B to 6D . The other mounting/demounting units  30 K  30 M and  30 Y have similar configurations to that of the mounting/demounting unit  30 C. As shown in  FIG. 5C , the mounting/demounting unit  30  includes the stationary member  35  and the movable member (first support assembly)  40 . The movable member  40  is movable in a +K1-axis direction and in a −K1-axis direction (first direction, connection direction). 
     The liquid container  50  is mounted to the mounting/demounting unit  30  by the following two operations. The state that the liquid container  50  is mounted to the mounting/demounting unit  30  is also called “mounted state (connected state)”. The mounted state (connected state) denotes the state that the liquid supply portion  57  (flow portion  57 ) of the liquid container  50  described later is connected with the liquid introduction portion (liquid introduction needle)  362  of the mounting/demounting unit  30  and that the circuit board  582  of the liquid container  50  is electrically connected with the electrical connection structure  382  of the mounting/demounting unit  30 . In the mounted state, the ink contained in the liquid container  50  is allowed to flow toward the printer  10 . 
     First Operation: 
     The user makes the mounting/demounting unit  30  in the first state and subsequently sets the liquid container  50  on the movable member  40 . 
     Second Operation: 
     After the first operation, the user presses the movable member  40  toward the stationary member  35  via the liquid container  50  and thereby makes the mounting/demounting unit  30  in the second state. 
     In the second state of the mounting/demounting unit  30 , a lock mechanism restricts the motion of the movable member  40  in the +K1-axis direction relative to the stationary member  35 . Pressing the movable member  40  inward (in the −K1-axis direction or first direction) relative to the stationary member  35  in the second state releases the lock by the lock mechanism. This enables the movable member  40  to be moved relative to the stationary member  35  such as to be protruded outward (in the +Z-axis direction) and changes over the state of the mounting/demounting unit  30  from the second state to the first state. 
     As shown in  FIG. 5B , the stationary member  35  includes a first mounting wall  307 A protruded upward in the direction of gravity and a second mounting wall  307 B protruded downward in the direction of gravity. Two through holes  302 H are formed in the first mounting wall  307 A, and two through holes  302 H are formed in the second mounting wall  307 B. Screws  302  (shown in  FIG. 5C ) as fixing members are inserted into the respective through holes  302 H. The mounting/demounting unit  30  (or more specifically the stationary member  35 ) is fixed to the surfaces  104  and  106  of the printer  10  (shown in  FIGS. 3 and 4 ) by the four screws  302 . More specifically, the mounting/demounting unit  30 K (shown in  FIG. 3 ) is fixed to the second surface  104  by a plurality of screws  302 . The mounting/demounting units  30 C,  30 M and  30 Y (shown in  FIG. 4 ) are fixed to the third surface  106  by a plurality of screws  302 . 
     As shown in  FIG. 5B , the stationary member  35  includes a liquid introduction mechanism  36  and a contact mechanism (electrical connection unit)  38 . The liquid introduction mechanism  36  and the contact mechanism  38  are respectively fixed to the stationary member  35 , so as to be supported on the outer wall (for example, apparatus third surface  106 ) via the stationary member  35 . 
     The liquid introduction mechanism  36  and the contact mechanism  38  are arranged side by side along the K2-axis direction. The liquid introduction portion (liquid supply connection structure)  362  of the liquid introduction mechanism  36  and the electrical connection structure (apparatus-side electrical connection structure)  382  of the contact mechanism  38  are arranged adjacent to each other in the K2-axis direction. With regard to the K2-axis direction, a direction from the liquid introduction mechanism  36  toward the contact mechanism  38  is +K2-axis direction, and a direction from the contact mechanism  38  toward the liquid introduction mechanism  36  is −K2-axis direction. In the mounting/demounting unit  30 , the Z-axis direction is also called “height direction”, the K1-axis direction is also called “width direction”, and the K2-axis direction is also called “depth direction”. 
     The liquid introduction mechanism  36  includes a liquid introduction main body  368 , the liquid introduction portion  362  and supply portion positioning structures  364 . The liquid supply portion of the liquid container  50  described later is connected with the liquid introduction portion  362 , so as to allow the ink contained in the liquid container  50  to flow. The liquid introduction portion  362  communicates with a record head of the printer  10  through a liquid flow tube  320 . The liquid flow tube  320  is a flexible hose. The liquid supply portion (liquid lead-out portion)  57  (shown in  FIG. 9 ) of the liquid container  50  is moved in the −K1-axis direction (first direction) accompanied with the motion of the movable member  40 , so as to be connected with the liquid introduction portion  362 . 
     As shown in  FIG. 5C , the liquid introduction portion  362  is formed in a needle-like shape in which ink is allowed to flow. The liquid introduction portion  362  is extended along a center axis CL. The direction along this center axis CL (in which the liquid introduction portion  362  is extended) is defined as K1-axis direction. The K1-axis direction is orthogonal to the Z-axis direction and the K2-axis direction. A plane defined by the K1-axis direction and the K2-axis direction is parallel to a plane defined by the X-axis direction and the Y-axis direction shown in  FIG. 1 . With regard to the K1-axis direction, an outward direction of the printer  10  is +K1-axis direction, and an inward direction of the printer  10  is −K1-axis direction. The liquid introduction portion  362  and the supply portion positioning structures  364  are provided on the liquid introduction main body  368  such as to be protruded in the +K1-axis direction from the liquid introduction main body  368 . 
     As shown in  FIG. 5B , the supply portion positioning structures  364  are arranged to surround the liquid introduction portion  362  about the center axis CL (shown in  FIG. 5C ). The supply portion positioning structures  364  serve to position the liquid supply portion  57  in a direction intersecting with the K1-axis direction (direction along a plane parallel to the Z-axis direction and the K2-axis direction according to this embodiment) in the process of connecting the liquid supply portion (liquid lead-out portion)  57  with the liquid introduction portion  362 . 
     The supply portion positioning structures  364  include a first supply portion positioning structure  364   a , a second supply portion positioning structure  364   b , a third supply portion positioning structure  364   c  and a fourth supply portion positioning structure  364   d . The first to the fourth supply portion positioning structures  364   a  to  364   d  are members respectively protruded from the liquid introduction main body  368 . The first supply portion positioning structure  364   a  is projected on the +K1-axis direction side of the other supply portion positioning structures  364   b  to  364   d . The first supply portion positioning structure  364   a  is located immediately above the liquid introduction portion  362  and is projected on the +K1-axis direction side of the liquid introduction portion  362 . In other words, the first supply portion positioning structure  364   a  is arranged to overlay the liquid introduction portion  362 . 
     The first supply portion positioning structure  364   a  is located above the liquid introduction portion  362  in the direction of gravity (on the +Z-axis direction side of the liquid introduction portion  362 ). The second supply portion positioning structure  364   b  is located on the −K2-axis direction side of the liquid introduction portion  362 . The third supply portion positioning structure  364   c  is located on the +K2-axis direction side of the liquid introduction portion  362 . The fourth supply portion positioning structure  364   d  is located below the liquid introduction portion  362  in the direction of gravity (on the −Z-axis direction side of the liquid introduction portion  362 ). The first and the fourth supply portion positioning structures  364   a  and  364   d  are opposed to each other across the liquid introduction portion  362  in the direction of gravity. The second and the third supply portion positioning structures  364   b  and  364   c  are opposed to each other across the liquid introduction portion  362  in the K2-axis direction. 
     The first to the fourth supply portion positioning structures  364   a  to  364   d  respectively have planes that are arranged to face the liquid introduction portion  362 . The liquid supply portion  57  of the liquid container  50  abuts on these planes, so that the liquid supply portion  57  is positioned relative to the liquid introduction portion  362  in a plane direction perpendicular to the K1-axis direction. 
     As shown in  FIG. 5B  and  FIG. 6A , the liquid introduction main body  368  further has a guide structure  365  located below the liquid introduction portion  362  in the direction of gravity. The guide structure  365  is a plate-like member extended in the +K1-axis direction from a lower end of the liquid introduction main body  368 . The guide structure  365  is placed in a guiding portion  465  that is included in the movable member  40  and is provided as a through hole as described later. The guide structure  365  is placed in the guiding portion  465  with some backlash in the Z-axis direction. This configuration allows the position of the movable member  40  to be finely adjusted relative to the liquid introduction portion  362  in the Z-axis direction when the movable member  40  is moved in the K1-axis direction. 
     As shown in  FIGS. 5B to 6A , the contact mechanism  38  includes the electrical connection structure (apparatus-side electrical connection structure)  382  with a plurality of (nine in this embodiment) apparatus-side terminals  381  and a plurality of (two in this embodiment) apparatus-side board positioning structures  384  and  385 . In the mounted state of the liquid container  50 , the apparatus-side terminals  381  of the electrical connection structure  382  come into contact with and are thereby electrically connected with a circuit board of the liquid container  50 . This allows for communication of various pieces of information (for example, the color of ink and the date of manufacture of the liquid container  50 ) between the circuit board of the liquid container  50  and the printer  10 . The apparatus-side terminal  381  is formed from an elastically deformable metal leaf spring. The apparatus-side board positioning structures  384  and  385  are arranged with the apparatus-side terminals  381  of the electrical connection structure  382  placed therebetween in the K2-axis direction (in the direction in which the liquid introduction mechanism  36  and the contact mechanism  38  are arranged side by side). The apparatus-side board positioning structures  384  and  385  serve to determine the final position of the circuit board of the liquid container  50  relative to the electrical connection structure  382  in the process of mounting the liquid container  50  to the mounting/demounting unit  30 . The apparatus-side board positioning structures  384  and  385  are members extended along the K1-axis direction. The details of the apparatus-side board positioning structures  384  and  385  will be described later. 
     The stationary member  35  includes a protective member  354  serving as a cover portion. The protective member  354  is arranged to cover at least the upper portion of the liquid introduction mechanism  36 . The protective member  354  is also arranged to cover at least the upper portion of the contact mechanism  38 . In other words, the protective member  354  is located above the liquid introduction portion  362  of the liquid introduction mechanism  36  and the electrical connection structure  382  of the contact mechanism  38  and is arranged to be protruded in the +K1-axis direction (direction opposite to the first direction) from the wall surface of the printer  10  (for example, the apparatus third surface  106  shown in  FIG. 2 ). This configuration reduces the possibility that any extraneous substance such as dust entering the housing space  26  from above the mounting/demounting unit  30  in the course of opening and closing the cover member  22  adheres to the liquid introduction portion  362  and the electrical connection structure  382 . This accordingly reduces the possibility that any extraneous substance is included in the ink supplied from the liquid container  50  to the printer  10 . This also reduces the likelihood that any extraneous substance adheres to the electrical connection structure  382 . This reduces failure in connection between the electrical connection structure  382  and the circuit board of the liquid container  50  described later. The presence of the protective member  354  also reduces the likelihood that the user directly touches the liquid introduction portion  362  and the electrical connection structure  382 . This reduces the possibility that the liquid introduction portion  362  and the electrical connection structure  382  are damaged. 
     As shown in  FIG. 5C , the movable member  40  is configured to be movable along the K1-axis direction relative to the stationary member  35 . The movable member  40  includes a base portion  41 , a supply portion support structure  42  and a board support structure  48 . The base portion  41  forms a front face (front wall) of the movable member  40  located on the +K1-axis direction side. The base portion  41  is arranged approximately parallel to the Z-axis direction and the K2-axis direction. The supply portion support structure  42  and the board support structure  48  are respectively connected with the base portion  41 . The supply portion support structure  42  and the board support structure  48  are members respectively extended in the +Z-axis direction (upward) from the base portion  41 . The guiding portion  465  that is a hole passing through in the K1-axis direction is formed in the base portion  41 . The guiding portion  465  is formed immediately below the supply portion support structure  42 . 
     The supply portion support structure  42  is a member configured to determine the position of the liquid container  50  (more specifically, its liquid supply portion) relative to the liquid introduction portion  362 . The supply portion support structure  42  comes into contact with a container body support assembly  51  of the liquid container  50  described later and thereby supports the container body support assembly  51  such that a liquid container body  52  is located below the container body support assembly  51  in the direction of gravity. When the mounting/demounting unit  30  is viewed along the K1-axis direction, the supply portion support structure  42  is provided at a position overlapping the liquid introduction portion  362 . The supply portion support structure  42  is provided to form a recessed shape toward the −Z-axis direction. The supply portion support structure  42  has grooves  407  formed on respective sides in the K2-axis direction. Insertion of positioning structures of the liquid container  50  described later into the grooves  407  restricts the motion of the liquid supply portion of the liquid container  50  and roughly positions the liquid container  50  relative to the mounting/demounting unit  30 . More specifically, the motion of the liquid supply portion of the liquid container  50  is restricted by a plurality of surfaces defining and forming the supply portion support structure  42  (for example, a first support surface  402 , a second support surface  403  and a third support surface  404 ). A cutout portion  406  is formed in the first support surface  402  of the supply portion support structure  42  located on the liquid introduction portion  362 -side. The cutout portion  406  is formed in a concave shape that is open on the +Z-axis direction side. When the mounting/demounting unit  30  is viewed along the K1-axis direction, the cutout portion  406  is provided at a position overlapping the liquid introduction portion  362 . In the first state where the movable member  40  is moved to the most +K1-axis direction side relative to the stationary member  35 , the cutout portion  406  is located on the +K1-axis direction side of the liquid introduction portion  362 . As shown in  FIG. 6A , a leading end of the liquid introduction portion  362  is located inside of the cutout portion  406  in the second state. 
     The board support structure  48  is a member configured to determine the position of the liquid container  50  (more specifically, its circuit board) relative to the contact mechanism  38 . When the mounting/demounting unit  30  is viewed along the K1-axis direction, the board support structure  48  is provided at a position overlapping the contact mechanism  38 . The board support structure  48  is provided to form a recessed shape toward the −Z-axis direction. The motion of the circuit board of the liquid container  50  is restricted by a plurality of surfaces defining and forming the board support structure  48  (for example, a first board support surface  482 ). 
     As shown in  FIG. 6D , part of a bottom  41   u  of the board support structure  48  (top of the base portion  41 ) forms an apparatus-side rotation restriction element  487 . The apparatus-side rotation restriction element  487  is a member projected on the +Z-axis direction side of the remaining part of the bottom  41   u . The apparatus-side rotation restriction element  487  abuts on the liquid container  50  to restrict rotation of the liquid container  50 . The board support structure  48  also has an apparatus-side restriction element  489  provided on a rear face of the base portion  41 . The apparatus-side restriction element  489  is a rib formed from the bottom to the top of the rear face of the base portion  41 . The apparatus-side restriction element  489  abuts on the liquid container  50  to restrict the motion of the liquid container  50  in the +K1-axis direction (direction opposite to the first direction). 
     As shown in  FIGS. 6B to 6D , the movable member  40  further includes a first side face (first side wall)  46 , a second side face (second side wall)  47  and a bottom  49  (bottom wall  49 ). The base portion  41 , the first side face  46  and the second side face  47  are members respectively extended in the +Z-axis direction from the bottom  49 . The first side face  46  and the second side face  47  are opposed to each other. The first side face  46  and the second side face  47  are approximately parallel to the Z-axis direction and the K1-axis direction. The bottom  49  is approximately parallel to the K1-axis direction and the K2-axis direction. 
     As shown in  FIG. 6D , a locking pawl  462  is provided on the first side face  46 . A locking pawl  472  (shown in  FIG. 6G ) is provided on the second side face  47 , like the first side face  46 . The locking pawls  462  and  472  are locked to the stationary member  35 , so as to prevent an excessive motion of the movable member  40  in the +K1-axis direction. This configuration prevents the movable member  40  from being dropped off from the stationary member  35 . 
     A-3. General Configuration of Liquid Introduction Mechanism  36   
       FIG. 6E  is a perspective view illustrating the mounting/demounting unit  30 .  FIG. 6F  is an exploded perspective view illustrating the mounting/demounting unit  30 .  FIG. 6G  is an F 5 Ba-F 5 Ba sectional view of  FIG. 5B . For the purpose of better understanding, a container body support assembly  51  of the liquid container  50  set to the mounting/demounting unit  30  is also illustrated in  FIG. 6E . For the purpose of better understanding, a −K1-axis direction end face of the movable member  40  is shown by single hatching in  FIG. 6F . For the purpose of better understanding, the liquid container  50  is also illustrated in  FIG. 6G . 
     As shown in  FIGS. 6E and 6F , the liquid introduction mechanism  36  is attached to the stationary member  35  (more specifically its second stationary member  33 ) by means of a screw  301 . The liquid introduction mechanism  36  includes a fixation structure  366  as a second support structure directly attached to the stationary member  35  and a coil spring  367  as a pressing member. 
     The coil spring  367  is inserted through the fixation structure  366 . The coil spring  367  has one end projected on the −K1-axis direction side of the fixation structure  366  and the other end projected on the +K1-axis direction side of the fixation structure  366 . The liquid introduction portion  362  is pressed in the +K1-axis direction by the coil spring  367 . The fixation structure  366  supports the liquid introduction mechanism  36  including the liquid introduction portion  362  to be displaceable in a direction intersecting with the first direction (−K1-axis direction). According to this embodiment, the direction intersecting with the first direction is a direction along a plane parallel to the K2-axis direction and the Z-axis direction. The details of this configuration will be described later. 
     As shown in  FIG. 6F , the stationary member  35  includes a first stationary member  32 , a second stationary member  33  and a sheet metal  323 . A second mounting wall  307 B is provided on the first stationary member  32 , and a first mounting wall  307 A is provided on the second stationary member  33 . The first stationary member  32  serves as an auxiliary member to support the second stationary member  33 . Two coil springs  39 A and  39 B are placed as pressing members between the first stationary member  32  and the movable member  40 . The coil springs  39 A and  39 B are arranged with the contact mechanism  38  and the liquid introduction mechanism  36  placed therebetween in the K2-axis direction. When there is no need to distinguish between the two coil springs  39 A and  39 B, these are expressed by a reference sign “ 39 ”. 
     The coil spring  39  has one end arranged to abut on the first stationary member  32  and the other end arranged to abut on the movable member  40 . A spring receiver  49 A of the movable member  40  is inserted in the other end of the coil spring  39 A, and a spring receiver  49 B of the movable member  40  is inserted in the other end of the coil spring  39 B. When there is no need to distinguish between the two spring receivers  49 A and  49 B, these are expressed by a reference sign “ 49 ”. 
     When the mounting/demounting unit  30  is in the second state shown in  FIG. 6A , the coil spring  39  presses the movable member  40  in the +K1-axis direction. In the second state, a non-illustrated lock mechanism restricts the motion of the movable member  40  in the +K1-axis direction. When the lock mechanism is unlocked, the movable member  40  is pressed toward the +K1-axis direction by the pressing force of the coil spring  39 , so that the mounting/demounting unit  30  shifts to the first state shown in  FIG. 5C . As shown in  FIG. 6G , the locking pawls  462  and  472  are locked to the stationary member  35 , in order to prevent the movable member  40  from being excessively moved in the +K1-axis direction relative to the stationary member  35 . This configuration prevents the movable member  40  from being dropped off from the stationary member  35 . 
     As shown in  FIGS. 6E and 6F , the sheet metal  323  is attached to the second stationary member  33  by means of a screw  325 . 
     A-4. Detailed Configuration of Contact Mechanism  38  and Mounting/Demounting Unit  30   
     The detailed configuration of the contact mechanism  38  and the mounting/demounting unit  30  is described with reference to  FIGS. 6H to 6V , in addition to  FIG. 6E ,  FIG. 6F  and  FIG. 6G .  FIG. 6H  is a perspective view illustrating part of the mounting/demounting unit  30 .  FIG. 6I  is a top view illustrating the mounting/demounting unit  30 .  FIG. 6J  is an F 6 I-F 6 I sectional view of  FIG. 6I .  FIG. 6K  is a partial enlarged view of an area R 6 J in  FIG. 6J .  FIG. 6L  is a perspective view illustrating the state that the contact mechanism  38  is mounted to the stationary member  35 .  FIG. 6M  is a perspective view illustrating the stationary member  35 .  FIG. 6N  is a front view illustrating the mounting/demounting unit  30 C.  FIG. 6O  is an F 6 N-F 6 N sectional view of  FIG. 6N .  FIG. 6P  is a perspective view illustrating the contact mechanism  38 .  FIG. 6Q  is a perspective view illustrating the contact mechanism  38 .  FIG. 6R  is a rear view of  FIG. 6E .  FIG. 6S  is a perspective view of  FIG. 6R .  FIG. 6T  is a perspective view illustrating the contact mechanism  38 .  FIG. 6U  is an enlarged view illustrating the apparatus-side board positioning structure  384  of the contact mechanism  38 .  FIG. 6V  is a perspective view illustrating the electrical connection structure  382 . The liquid container  50  is also illustrated in  FIG. 6I . Part of the liquid container  50  is also illustrated in  FIGS. 6N, 6P and 6Q . The sheet metal  323  and the coil spring  325  shown in  FIG. 6E  are omitted from the illustration of  FIG. 6R . 
     As shown in  FIGS. 6L and 6M , the second stationary member  33  has a fixation structure  37  which the contact mechanism  38  is mounted to. The contact mechanism  38  is mounted to the fixation structure  37  with some backlash. This configuration causes the electrical connection structure  382  of the contact mechanism  38  to be displaceable in a direction intersecting with the first direction (−K1-axis direction) (in the embodiment, a direction along a plane parallel to the Z-axis direction and the K2-axis direction). The details of this configuration will be described later. 
     As shown in  FIG. 6M , the fixation structure  37  has a receiving space  37 S configured to receive the contact mechanism  38  therein. The fixation structure  37  has a first partition wall  37 A and a second partition wall  37 B arranged to define the receiving space  37 S. The first partition wall  37 A forms a side face on the −K2-axis direction side of the receiving space  37 S. The second partition wall  37 B forms a side face on the +K2-axis direction side of the receiving space  37 S. 
     The first partition wall  37 A includes a first mounting portion  377  (right-side first mounting portion  377 ), a second mounting portion  371  (right-side second mounting portion  371 ) and an apparatus-side upper restriction portion  377   a . The first and second mounting portions  377  and  371  are portions to which the contact mechanism  38  is mounted. The first mounting portion  377  is a groove arranged to face the receiving space  37 S. The second mounting portion  371  is a through hole arranged to receive part of the contact mechanism  38  therein. The second mounting portion  371  may, however, be formed in any other shape to receive part of the contact mechanism  38  therein and may be formed as a groove. The apparatus-side upper restriction portion  377   a  is a surface facing down in the direction of gravity. The apparatus-side upper restriction portion  377   a  abuts on the substrate unit  58  when the substrate unit  58  of the liquid container  50  (shown in  FIG. 7 ) is connected with the electrical connection structure  382  of the contact mechanism  38 , so as to restrict the upward motion of the substrate unit  58  in the direction of gravity (Z-axis direction). 
     The second partition wall  37 B has a similar configuration to that of the first partition wall  37 A with difference only in their positions. More specifically, the second partition wall  37 B includes a first mounting portion  378  (left-side first mounting portion  378 ) shown in  FIG. 6R , a second mounting portion  372  (left-side second mounting portion  372 ) shown in  FIG. 6M  and an apparatus-side upper restriction portion  377   b  (shown in  FIG. 6M ). The first mounting portion  378  has the same configuration as that of the first mounting portion  377  of the first partition wall  37 A, and the second mounting portion  372  has the same configuration as that of the second mounting portion  371  of the first partition wall  37 A. The apparatus-side upper restriction portion  377   b  has the same configuration as that of the apparatus-side upper restriction portion  377   a  of the first partition wall  37 A. When there is no need to distinguish between the two apparatus-side upper restriction portions  377   a  and  77   b , these are expressed by a reference sign “ 377 M”. 
     As shown in  FIG. 6O , the apparatus-side upper restriction portion  377 M is located above the apparatus-side terminals  381  in the direction of gravity. The apparatus-side upper restriction portion  377 M has a tapered +K1-axis direction end. The apparatus-side upper restriction portion  377 M has a −K1-axis direction end that forms a horizontal plane. The +K1-axis direction end of the apparatus-side upper restriction portion  377 M is located on the +K1-axis direction side of the apparatus-side terminals  381 . 
     As shown in  FIG. 6P , the contact mechanism  38  includes a coil spring  387  as a pressing member, the electrical connection structure  382  (shown in  FIG. 5B ), and a holding member  388  configured to hold the electrical connection structure  382 . 
     As shown in  FIG. 6J , a convex (spring receiver) of the sheet metal  323  is inserted in one end  387 A of the coil spring  387 . The one end  387 A of the coil spring  387  is accordingly supported by the sheet metal  323 . The other end  387 B of the coil spring  387  is placed inside of the holding member  388 . As shown in  FIG. 6J  and  FIG. 6R , a rib  393  as a spring receiver is provided inside of the holding member  388 . The other end  387 B of the coil spring  387  is placed inside of the holding member  388  via an opening formed in a rear wall (wall on the −K1-axis direction side) of the holding member  388 . The rib  393  is inserted in the other end  387 B. This configuration causes the other end  387 B of the coil spring  387  to be supported by the holding member  388 . The coil spring  387  presses the holding member  388  in the +K1-axis direction. 
     As shown in  FIGS. 6P, 6Q and 6T , the holding member  388  includes a first side wall  394  and a second side wall  396 . The first side wall  394  and the second side wall  396  are opposed to each other. The first side wall  394  is located on the −K2-axis direction side, and the second side wall  396  is located on the +K2-axis direction side. The first side wall  394  and the second side wall  396  are surfaces approximately along the direction of gravity (Z-axis direction). 
     As shown in  FIG. 6P  and  FIG. 6Q , the contact mechanism  38  includes a first contact-side positioning structure (apparatus-side board positioning structure)  384  and a second contact-side positioning structure (apparatus-side board positioning structure)  385  serving as the positioning structures (apparatus-side board positioning structures). The first and the second contact-side positioning structures  384  and  385  serve to position the circuit board  582  of the liquid container  50  (more specifically its liquid container side terminals  581  shown in  FIG. 13A ) and the apparatus-side terminals  381  of the electrical connection structure  382  relative to each other. More specifically, the liquid container-side terminals  581  and the apparatus-side terminals  381  are positioned relative to each other in the −K1-axis direction (first direction) and in a direction intersecting with the −K1-axis direction (direction along a plane parallel to the Z-axis direction and the K1-axis direction). 
     The first and the second contact-side positioning structures  384  and  385  are arranged with the electrical connection structure  382  placed therebetween in the K2-axis direction. The first and the second contact-side positioning structures  384  and  385  have similar configurations with difference only in their positions. 
     The first and the second contact-side positioning structures  384  and  385  are members respectively extended along the K1-axis direction (connecting direction). As shown in  FIG. 6P , the first contact-side positioning structure  384  is protruded outward from the first side wall  394 . As shown in  FIG. 6Q , the second contact-side positioning structure  385  is protruded outward from the second side wall  396 . 
     As shown in  FIG. 6P , the first contact-side positioning structure  384  has a locking element  384   e  on its −K1-axis direction end. As shown in  FIG. 6Q , the second contact-side positioning structure  385  has a locking element  385   e  on its −K1-axis direction end. The locking element  384   e  is locked to the wall surface of the second mounting portion  372  as shown in  FIGS. 6L and 6M , and the locking element  385   e  is locked to the wall surface of the second mounting portion  371  (not shown). This configuration restricts the motion in the +K1-axis direction of the holding member  388  that is pressed in the +K1-axis direction by the coil spring  387  (shown in  FIG. 6J ). 
     As shown in  FIG. 6U , the first contact-side positioning structure  384  has first to fourth restriction elements  384   a  to  384   d  on its +K1-axis direction end. The first to the fourth restriction elements  384   a  to  384   d  serve to position the substrate unit  58  (shown in  FIG. 9 ) of the liquid container  50  relative to the electrical connection structure  382 . More specifically, the first contact-side positioning structure  384  achieves positioning in the first direction (−K1-axis direction) and in a direction intersecting with the first direction (direction parallel to a plane defined by the Z-axis direction and the K2-axis direction). 
     As shown in  FIG. 6U , the first restriction element  384   a  forms a top face of the first contact-side positioning structure  384 . The second restriction element  384   b  forms a side face of the first contact-side positioning structure  384 . As shown in  FIGS. 6T and 6U , the third restriction element  384   c  forms a leading edge face of the first contact-side positioning structure  384 . The fourth restriction element  384   d  forms a bottom face of the first contact-side positioning structure  384 . The first restriction element  384   a  is located on the +Z-axis direction side. The second restriction element  384   b  is located on the −K2-axis direction side. The third restriction element  384   c  is located on the +K1-axis direction side. The fourth restriction element  384   d  is located on the −Z-axis direction side. The respective restriction elements  384   a  to  384   d  are approximately planar surfaces. 
     As shown in  FIG. 6T , the second contact-side positioning structure  385  has a similar configuration to that of the first contact-side positioning structure  384 . More specifically, the second contact-side positioning structure  385  has a first restriction element  385   a , a second restriction element  385   b , a third restriction element  385   c  and a fourth restriction element  385   d . The first to the fourth restriction elements  385   a  to  385   d  serve to position the substrate unit  58  (shown in  FIG. 9 ) of the liquid container  50  relative to the electrical connection structure  382 . More specifically, like the first contact-side positioning structure  384 , the second contact-side positioning structure  385  achieves positioning in the first direction (−K1-axis direction) and in the direction intersecting with the first direction (direction parallel to the plane defined by the Z-axis direction and the K2-axis direction). The first restriction element  385   a  forms a top face of the second contact-side positioning structure  385 . The second restriction element  385   b  forms a side face of the second contact-side positioning structure  385 . The third restriction element  385   c  forms a leading edge face of the second contact-side positioning structure  385 . The fourth restriction element  385   d  forms a bottom face of the second contact-side positioning structure  385 . The first restriction element  385   a  is located on the +Z-axis direction side. The second restriction element  385   b  is located on the +K2-axis direction side. The third restriction element  385   c  is located on the +K1-axis direction side. The fourth restriction element  385   d  is located on the −Z-axis direction side. The respective restriction elements  385   a  to  385   d  are approximately planar surfaces. 
     As shown in  FIG. 6T , the electrical connection structure  382  is held on the +K1-axis direction side of the holding member  388 . As shown in  FIG. 6V , the electrical connection structure  382  includes a terminal holder  62  held on the holding member  388 , nine apparatus-side terminals  381 A to  381 I held on the terminal holder  62  and a connector  602  held on the terminal holder  62 . When there is no need to distinguish among the nine apparatus-side terminals  381 A to  381 I, these are expressed by a reference sign “ 381 ”. 
     As shown in  FIG. 6T , a surface  62   fa  of the terminal holder  62  is inclined such that a lower end  62   b  is located on the −K1-axis direction side of an upper end  62   u . Respective one ends of the apparatus-side terminals  381  are exposed on the surface  62   fa . Respective other ends of the apparatus-side terminals  381  are electrically connected with the connector  602  (shown in  FIG. 6V ). The connector  602  is electrically connected with a controller of the printer  10  via wiring. 
     As shown in  FIG. 6V , the plurality of apparatus-side terminals  381 A to  381 I that constitute an apparatus-side terminal group are arranged in two lines LN 1  and LN 2  formed at different locations in the Z-axis direction. The lines LN 1  and LN 2  are parallel to the K2-axis direction. 
     As shown in  FIG. 6P  and  FIG. 6Q , the first side wall  394  has a support wall portion  392  protruded in the −K2-axis direction (outward). The support wall portion  392  is provided on the top of the first side wall  394 . The support wall portion  392  is a member extended along the K1-axis direction. The second side wall  396  has a support wall portion  395  protruded in the +K2-axis direction (outward). The support wall portion  395  is formed in a similar configuration to that of the support wall portion  392  of the first side wall  394 . 
     The first contact-side positioning structure  384 , the second contact-side positioning structure  385 , the support wall portion  392  and the support wall portion  395  provided in the holding member  388  as described above are members configured to support the holding member  388  to the second stationary member  33  to be displaceable in an in-plane direction perpendicular to the K1-axis direction. The mechanism for such displacement is described in detail below. 
     As shown in  FIG. 6R , the support wall portion  392  is inserted into the first mounting portion  377  of the fixation structure  37 , while the support wall portion  395  is inserted into the first mounting portion  378  of the fixation structure  37 . The locking element  385   e  is inserted into the second mounting portion  371 , while the locking element  384   e  is inserted into the second mounting portion  372 . The support wall portions  392  and  395  are inserted into the first mounting portions  377  and  378  with some clearance (backlash) in at least the direction of gravity (Z-axis direction). The locking elements  385   e  and  384   e  are inserted into the second mounting portions  371  and  372  with some clearance (backlash) in at least the K2-axis direction. This configuration causes the holding member  388  provided to hold the electrical connection structure  382  to be mounted to the stationary member  35  such as to be displaceable in an in-plane direction (the Z-axis direction and the K2-axis direction) perpendicular to the K1-axis direction. 
     As shown in  FIG. 6K , a restriction element  597  provided as a projection on a circuit board holding structure  59  of the liquid container  50  described later abuts on the apparatus-side restriction element  489  provided in the movable member  40 . This restricts the motion of the liquid container  50  in the +K1-axis direction (direction opposite to the first direction). 
     A-5. Configuration of Liquid Container  50 : 
       FIG. 7  is a first perspective view illustrating the liquid container  50 .  FIG. 8  is a second perspective view illustrating the liquid container  50 . The Z axis, the K1 axis and the K2 axis in the state that the liquid container  50  is mounted to the mounting/demounting unit  30  (in the mounted state) are shown in  FIGS. 7 and 8 .  FIGS. 7 and 8  illustrate the liquid container  50  in the state that the liquid container  50  is filled with ink as the liquid but is not yet mounted to the mounting/demounting unit  30  (prior to consumption of ink by the printer  10 ) (unused state or initial state). The Z axis, the K1 axis and the K2 axis that are orthogonal to one another are also shown as appropriate in subsequent drawings. The configuration is described with regard to the liquid container  50 C as an example with reference to  FIG. 7  and subsequent drawings. The other liquid containers  50 K,  50 M and  50 Y have similar configurations to that of the liquid container  50 C. 
     The Z axis, the K1 axis and the K2 axis that are orthogonal to one another may be defined as follows. In the state that the liquid container  50  is connected with the printer  10 , the Z axis direction is the direction of gravity (vertical direction). The +Z-axis direction is upward in the direction of gravity (upward in the vertical direction), and the −Z-axis direction is downward in the direction of gravity (downward in the vertical direction). The K1-axis direction that is the direction along the K1 axis is the horizontal direction. The −K1-axis direction is the connecting direction (moving direction or first direction) of the liquid container  50  in the process of connecting the liquid container  50  with the printer  10 . As described later, in the process of connecting the liquid container  50  to the printer  10 , moving a liquid supply unit  55  described later (shown in  FIG. 7 ) in the connecting direction (−K1-axis direction) causes the liquid supply unit  55  (more specifically, its liquid supply portion  57 ) to be connected with the liquid introduction portion (liquid receiving portion)  362  provided in the printer  10  and causes the substrate unit  58  (more specifically, its electrical connection structure  582 ) to be connected with the electrical connection structure  382  (shown in  FIG. 5C ) provided in the printer  10 . The +K1-axis direction is the demounting direction in the process of demounting the liquid container  50  from the printer  10 . The connecting direction is the −K1-axis direction that is the horizontal direction according to this embodiment, but this is not restrictive. The connecting direction may be any direction including a horizontal direction component. The K2-axis direction is a direction that is orthogonal to the direction of gravity (Z-axis direction) and the K1-axis direction. 
     As shown in  FIG. 7 , the liquid container  50  includes a liquid container body (liquid containing bag)  52  and a container body support assembly  51  attached to the liquid container body  52 . The liquid container body  52  is configured to contain ink as the liquid. The liquid container body  52  is attached to the container body support assembly  51  in the state that the outer surface is exposed. In other words, the liquid container body  52  is not placed in a case or the like but is configured to be visible from outside. The volume of the liquid container body  52  decreases with reduction of ink contained therein. 
     The liquid container body  52  includes a first sheet  521 , a second sheet  522  and a third sheet  523 . The first to the third sheets  521  to  523  are configured to define a space for containing ink inside thereof. One end of the liquid container body  52  to which the container body support assembly  51  is attached is defined as one end  501  (one end portion or upper end), and an opposite end opposed to the one end  501  is defined as the other end  502  (other end portion or bottom end). One edge (+K2-axis direction edge) of the liquid container body  52  is defined as first side edge  503  (first side edge portion), and the other edge (−K2-axis direction edge) is defined as second side edge  504  (second side edge portion). 
     As shown in  FIG. 7  and  FIG. 8 , in the mounted state of the liquid container  50 , the first sheet  521  and the second sheet  522  form side faces of the liquid container body  52 . In the mounted state of the liquid container  50 , the third sheet  523  forms a bottom face of the liquid container body  52 . The first sheet  521  and the second sheet  522  are arranged to face each other. Respective peripheral areas  51 W of the first sheet  521  and the second sheet  522  are partly welded to each other. More specifically, one end  501 -portions, first side edge  503 -portions and second side edge  504 -portions of the respective peripheral areas  51 W are welded. For the purpose of better understanding, the welded portions of the first and the second sheets  521  and  522  are shown by cross-hatching in  FIGS. 7 and 8 . The container body support assembly  51  is welded to the one end  501  of the liquid container body  52  (more specifically, the respective one ends of the first and the second sheets  521  and  522 ). In other words, the container body support assembly  51  is a member attachable to the one end  501  of the liquid container body  52 . For the purpose of better understanding, the welded portions of the container body support assembly  51  to the first and the second sheets  521  and  522  are shown by solid-line single hatching in  FIGS. 7 and 8 . 
     As shown in  FIG. 7 , a peripheral area  51 Y of the third sheet  523  is welded to portions of the peripheral areas  51 W of the first and the second sheets  521  and  522 . The welded portions of the third sheet  523  to the first and the second sheets  521  and  522  are shown by one-dot chain line single hatching. As described above, the liquid container body  52  of the embodiment is in such a form that the three sheets  521 ,  522  and  523  are bonded by welding or the like (pouch-like form having a bottom face). 
     The first to the third sheets  521  to  523  are respectively flexible members. The material employed for the first to the third sheets  521  to  523  may be, for example, polyethylene terephthalate (PET), nylon or polyethylene. A laminated structure by stacking a plurality of films may be employed to form the first to the third sheets  521  to  523 . In this laminated structure, for example, an outer layer may be formed from PET or nylon having excellent impact resistance and an inner layer may be formed from polyethylene having excellent ink resistance. Additionally, a film including a deposition layer of aluminum or the like may be used as one component of the laminated structure. This enhances the gas barrier property and thereby suppresses, for example, a change in concentration of ink contained in the liquid container body  52 . The material of the liquid container body  52  may be determined arbitrarily as described above. 
     The shapes and the sizes of the respective liquid container bodies  52  may be set arbitrarily. For example, the liquid container body  52  containing black ink may have a larger capacity (larger size) than that of the liquid container body  52  containing another color (for example, cyan) ink. In another example, the liquid container body  52  is in the form that the first to the third sheets  521  to  523  are bonded by welding or the like according to the embodiment, but may be in such a form that the first and the second sheets  521  and  522  are bonded by welding or the like with omission of the third sheet  523  (pillow-like form). As described above, the liquid container body  52  and the operation member  53  are provided as separate members. This configuration allows the type (shape, size and material) of the liquid container body  52  to be readily changed, while using the same operation member  53 . The shape, the size and the material of the liquid container body  52  may thus be set according to, for example, the properties and the amount of the liquid contained in the liquid container body  52 . This enhances the flexibility of design. 
     The container body support assembly  51  includes an operation member (handle portion)  53 , a liquid supply unit  55  and a substrate unit  58 . The operation member  53  is a frame-like member that is open in the K1-axis direction. The operation member  53  includes a grip portion  54  located on a +Z-axis direction end and a pressed portion  545  located on a −Z-axis direction end (shown in  FIG. 8 ). The grip portion  54  is a portion gripped by the user to support (hold) the liquid container  50 . The grip portion  54  is extended along the K2-axis direction. The grip portion  54  of the operation member  53  is formed in a rectangular frame-like shape according to this embodiment but may be formed in a C shape or in a T shape. 
     The pressed portion  545  is a portion pressed by the user in the process of connecting the liquid container  50  with the printer  10 . In other words, the pressed portion  545  is a manually pressed portion. The user presses the pressed portion  545  in the −K1-axis direction (connecting direction), so as to move the movable member  40  (shown in  FIG. 6I ) with the liquid container  50  set thereon in the −K1-axis direction. The pressed portion  545  is provided on the opposite side of the operation member  53  opposite to the side where the liquid supply unit  55  and the substrate unit  58  are provided. The pressed portion  545  is provided on a −Z-axis direction end of the operation member  53 . The pressed portion  545  is provided to be protruded outward (in the +K1-axis direction) from the operation member  53 . This configuration facilitates discrimination of the pressed portion  545  from the remaining part. 
     As shown in  FIG. 7 , the liquid supply unit  55  and the substrate unit  58  are provided on a −Z-axis direction end of the operation member  53 . The liquid supply unit  55  and the substrate unit  58  are arranged side by side in the K2-axis direction. The liquid supply unit  55  serves to supply ink contained in the liquid container body  52  to outside (for example, the liquid introduction portion  362  shown in  FIG. 5B ). The substrate unit  58  serves to be electrically connected with the apparatus-side terminals  381  of the contact mechanism  38 . The liquid supply unit  55  and the substrate unit  58  are provided to be protruded outward (in the −K1-axis direction) from the operation member  53 . The liquid supply unit  55  and the substrate unit  58  are protruded in the same direction. The protruding direction of the substrate unit  58  and the protruding direction of the liquid supply portion  57  may not be necessarily identical with each other but may be arranged approximately parallel to each other. The substrate unit  58  and the liquid supply unit  55  are protruded from the operation member  53  toward the same direction (−K1-axis direction) relative to the operation member  53 . 
       FIG. 9  is a first perspective view illustrating part of the liquid container  50 .  FIG. 10  is a second perspective view illustrating part of the liquid container  50 .  FIG. 11  is a third perspective view illustrating part of the liquid container  50 .  FIG. 12  is a fourth perspective view illustrating part of the liquid container  50 .  FIG. 13  is a front view illustrating part of the liquid container  50 .  FIG. 14  is a rear view illustrating part of the liquid container  50 .  FIG. 15  is a top view illustrating part of the liquid container  50 .  FIG. 16  is a right side view illustrating part of the liquid container  50 .  FIG. 17A  is an F 13 -F 13  sectional view of  FIG. 13 .  FIG. 17B  is a front view illustrating the circuit board  582 .  FIG. 17C  is a view from an arrow F 17 B in  FIG. 17B .  FIG. 17D  is an F 13   a -F 13   a  partial sectional view of  FIG. 13 .  FIG. 17E  is a perspective view illustrating a groove  593   t .  FIG. 17F  is a perspective view illustrating a groove  592   t . The liquid container body  52  of the liquid container  50  is omitted from the illustration in  FIGS. 9 to 17A . 
     With regard to the operation member  53 , the Z-axis direction is also called “height direction”, the K1-axis direction is also called “thickness direction”, and the K2-axis direction is also called “width direction”. According to this embodiment, the “height direction”, “thickness direction” and “width direction” of the operation member  53  correspond to the “height direction”, “thickness direction” and “width direction” of the liquid container  50 . According to this embodiment, the dimensions of the liquid container  50  decrease in the sequence of the height, the width and the thickness. 
     As shown in  FIGS. 9 and 10 , the operation member  53  includes a first connecting portion  546 , a second connecting portion  547 , a base portion  548  and a mounting portion  549  to which the liquid container body  52  is mounted by welding or the like, in addition to the grip portion  54 . 
     The grip portion  54 , the first connecting portion  546 , the second connecting portion  547  and the base portion  548  are respectively in rod-like shapes. The grip portion  54 , the first connecting portion  546 , the second connecting portion  547  and the base portion  548  form a frame-like member. Accordingly a receiving space  542  in an approximately rectangular shape is defined and formed in the operation member  53  to receive the user&#39;s hand. As shown in  FIG. 11 , the grip portion  54  has a grip surface (support surface)  541  that is exposed to the receiving space  542 . The grip surface  541  is a plane approximately perpendicular to the Z-axis direction in the mounted state. 
     As shown in  FIG. 9 , the base portion  548  is extended along the K2-axis direction. The liquid supply unit  55  and the substrate unit  58  are attached to the base portion  548 . The liquid supply unit  55  and the substrate unit  58  are accordingly linked with each other via the base portion  548 . The liquid supply unit  55  and the substrate unit  58  accordingly move in conjunction with the motion of the base portion  548 . This configuration allows the user to operate the motions of the liquid supply unit  55  and the substrate unit  58  used for connecting the liquid container  50  with the printer  10  by simply operating the motion of one member (base portion  548  according to this embodiment). The term “linked” herein means that members linked with each other are connected to be movable in conjunction with each other. 
     The mounting portion  549  is located on the opposite side that is opposite to the side where the grip portion  54  is located across the base portion  548 . The mounting portion  549  is arranged adjacent to the base portion  548 . The mounting portion  549  is extended along the K2-axis direction. The mounting portion  549  is a portion which one end  501  of the liquid container body  52  (shown in  FIG. 7 ) is mounted to (or joined with) by welding or the like. As shown in  FIG. 13  and  FIG. 17A , the mounting portion  549  has a lead-out portion  550  configured to cause ink contained in the liquid container body  52  to be flowed to the liquid supply portion  57 . Connecting a flow path member  70  with the lead-out portion  550  causes ink flowing in the flow path member  70  to be flowed to the liquid supply portion  57  described later via the lead-out portion  550 . For the purpose of better understanding, part of the mounting portion  549  to which the liquid container body  52  is mounted is shown by single hatching in  FIGS. 13 and 14 . 
     As shown in  FIGS. 9 and 10 , the liquid supply unit  55  includes the liquid supply portion (liquid lead-out portion)  57  and a container body-side support structure  56 . The container body-side support structure  56  is provided separately from the liquid supply portion  57 , a small clearance is formed between the container body-side support structure  56  and the liquid supply portion  57 . 
     The liquid supply portion  57  is configured to cause the ink contained in the liquid container body  52  to be flowed to the printer  10 . The liquid supply portion  57  includes a liquid supply port  572  on one end and a supply connecting portion  573  on the other end. The liquid supply port  572  is arranged to communicate with inside of the liquid container body  52  and causes the ink contained in the liquid container body  52  to be flowed out to the outside (printer  10 ). The liquid supply portion  57  is extended from the operation member  53  to face in a first direction (−K1-axis direction) that is a direction intersecting with the direction of gravity (Z-axis direction) in the process of supplying ink to the printer  10 . The liquid introduction portion  362  (shown in  FIG. 5B ) is inserted into the liquid supply port  572  in the mounted state of the liquid container  50 . The liquid supply port  572  defines a plane (surface defined by the Z-axis direction and the K2-axis direction). The liquid supply port  572  is open toward the first direction (−K1-axis direction, connecting direction). The opening direction herein is a direction that is perpendicular to the plane defined by the liquid supply port  572  and is a direction toward outside. The liquid supply port  572  is, however, not necessarily limited to the configuration that the liquid supply port  572  is open toward the first direction but may be open toward a direction including a first direction component. 
     The supply connecting portion  573  is connected with the operation member  53 . The liquid supply portion  57  is a tubular member (ring-shaped member) extended along the K1-axis direction (center axis CT direction). 
     The liquid supply portion  57  has a center axis CT. The center axis CT is parallel to the K1-axis direction. With regard to the K1-axis direction, a direction from the liquid supply port  572  toward the supply connecting portion  573  is +K1-axis direction, and a direction from the supply connecting portion  573  toward the liquid supply port  572  is −K1-axis direction. 
     As shown in  FIG. 15 , the liquid supply port  572  is arranged at a position that does not overlap with the operation member  53  when the liquid container  50  is viewed from the +Z-axis direction (i.e., from the side where the grip portion  54  is located). 
     As shown in  FIG. 9 , in the unused state of the liquid container  50 , the liquid supply port  572  is closed by a film  99 . This configuration suppresses leakage of ink from the liquid supply port  572  to outside before the liquid container  50  is mounted to the mounting/demounting unit  30  (shown in  FIG. 5 ). The film  99  is broken by the liquid introduction portion  362  (shown in  FIG. 5B ) in the process of mounting the liquid container  50  to the mounting/demounting unit  30 . 
     As shown in  FIGS. 9 to 11 , positioning structures  577  are provided to surround the outer circumference of the liquid supply portion  57  about the center axis CT. The positioning structures  577  abut on the supply portion positioning structures  364  of the liquid introduction portion  362  (shown in  FIG. 5B ) so as to position the liquid supply portion  57  relative to the liquid introduction portion  362  in the process of connecting the liquid container  50  with the printer  10 . The positioning structures  577  may be regarded as part of the liquid supply portion  57 . 
     The positioning structures  577  include a first container-side positioning structure  577   a , a second container-side positioning structure  577   b , a third container-side positioning structure  577   c  and a fourth container-side positioning structure  577   d . The first to the fourth container-side positioning structures  577   a  to  577   d  are members protruded from the liquid supply portion  57  (protruded members). The first to the fourth container-side positioning structures  577   a  to  577   d  are members extended along the K1-axis direction. Respective −K1-axis direction ends of the first to the fourth container-side positioning structures  577   a  to  577   d  are arranged near to the liquid supply port  572 . 
     The first container-side positioning structure  577   a  is located on the upper side of the liquid supply portion  57  in the direction of gravity (on the +Z-axis direction side). The second container-side positioning structure  577   b  is located on the −K2-axis direction side of the liquid supply portion  57 . The third container-side positioning structure  577   c  is located on the +K2-axis direction side of the liquid supply portion  57 . The fourth container side positioning structure  577   d  is located on the lower side of the liquid supply portion  57  in the direction of gravity (on the −Z-axis direction side). The first and the fourth container-side positioning structures  577   a  and  577   d  are opposed to each other in the Z-axis direction. The second and the third container-side positioning structures  577   b  and  577   c  are opposed to each other in the K2-axis direction. 
     As shown in  FIG. 17A , a valve mechanism  551  is placed inside of the liquid supply portion  57  to open and close a liquid flow path formed by the liquid supply portion  57 . The valve mechanism  551  includes a valve seat  552 , a valve element  554  and a spring  556 . The valve seat  552 , the valve element  554  and the spring  556  are placed in the liquid supply portion  57  to be arranged in this sequence from the liquid supply port  572  toward the supply connecting portion  573  of the liquid supply portion  57 . 
     The valve seat  552  is an approximately annula 53  r member. The valve seat  552  is formed from an elastic body, for example, a rubber or an elastomer. The valve seat  552  is pressed into the liquid supply portion  57 . The valve element  554  is an approximately cylindrical member. The valve element  554  is arranged to close a hole formed in the valve seat  552  (valve hole) in the state before mounting of the liquid container  50  to the mounting/demounting unit  30 . The spring  556  is a compression coil spring. The spring  556  presses the valve element  554  in a direction toward the valve seat  552 . In the mounted state of the liquid container  50 , the liquid introduction portion  362  (shown in  FIG. 5B ) presses the vale element  554  toward the supply connecting portion  573 , so as to move the valve element  554  toward the supply connecting portion  573 . The valve element  554  is accordingly separated from the valve seat  552  to set the valve mechanism  551  in the open position. In the open position of the valve mechanism  551 , the ink contained in the liquid container body  52  (shown in  FIG. 7 ) is allowed to flow through the flow path member  70 , an inner flow path  558  of the operation member  53  and the liquid supply portion  57  to outside. 
     As shown in  FIG. 9 , the container body-side support structure  56  is configured to roughly position the liquid container body  52  including the liquid supply port  572  relative to the printer  10  in the process of connecting the liquid container  50  with the printer  10 . The container body-side support structure  56  is in a recessed shape that is open on the +Z-axis direction side. The container body side support structure  56  is arranged to surround the circumference of the liquid supply portion  57  about the center axis CT except the Z-axis direction side (upper side in the direction of gravity). The container body-side support structure  56  is arranged at a position adjacent to the liquid supply port  572  of the liquid supply portion  57 . When the operation member  53  is formed from a material that is not readily deformable, the container body-side support structure  56  may be provided in the operation member  53  at a position some distance away from the liquid supply port  572 . The container body-side support structure  56  is protruded in the −K1-axis direction from the operation member  53 . 
     The container body-side support structure  56  is placed inside of the supply portion support structure  42  of the mounting/demounting unit  30  (shown in  FIG. 5C ) in the process of connecting the liquid container  50  with the printer  10 . This configuration causes a plurality of surfaces defining and forming the supply portion support structure  42  (for example, the first support surface  402 , the second support surface  403  and the third support surface  404  shown in  FIG. 5C ) to abut on the container body-side support structure  56 . This restricts the motion of the liquid supply portion  57  and roughly positions the liquid container  50 . The container body-side support structure  56  abuts on the third support surface  404  when the liquid container  50  is set in the movable member  40  of the mounting/demounting unit  30 , so that the liquid container body  52  is supported by the movable member  40  to be suspended below the grip portion  54  in the direction of gravity by the dead weight. 
     The liquid supply unit  55  serves to supply the ink contained in the liquid container body  52  (shown in  FIG. 7 ) to the printer  10 . The liquid supply unit  55  may thus be regarded as “liquid supply assembly”. The liquid supply unit  55  provided as the liquid supply assembly includes the liquid supply portion (liquid flow portion)  57  with the liquid supply port  572  and the container body-side support structure  56  on one end. 
     As shown in  FIGS. 9 and 10 , the substrate unit  58  includes a circuit board  582  as a container-side electrical connection structure and a circuit board holding structure  59  as a holder structure (placement structure). As shown in  FIG. 9 , the circuit board holding structure  59  is configured to position the circuit board  582  relative to the printer  10  in the process of connecting the liquid container  50  with the printer  10 . The circuit board holding structure  59  is provided integrally with the operation member  53 . According to this embodiment, the circuit board holding structure  59  is integrally molded with the operation member  53 , so as to be provided integrally with the operation member  53 . The term “provided integrally” means that the circuit board holding structure  59  is provided in the operation member  53  to be in conjunction with the motion of the operation member  53 . According to another embodiment, the circuit board holding structure  59  may be attached to the operation member  53  by welding or the like, so as to be provided integrally with the operation member  53 . 
     The circuit board holding structure  59  and the liquid supply portion  57  are arranged side by side in a direction (K2-axis direction) that intersects with the first direction (−K1-axis direction). The circuit board holding structure  59  is configured to hold (support or place) the circuit board  582 . In other words, the circuit board holding structure  59  is configured to place contacts cp of the circuit board  582 . The circuit board holding structure  59  is configured to hold (place) the circuit board  582  (its contacts cp) to be located above the liquid container body  52  in the process of connecting the liquid container  50  with the printer  10 . The circuit board holding structure  59  is a member having rigidity. More specifically, the circuit board holding structure  59  has such a level of rigidity that does not allow for displacement of the circuit board  582  when the liquid container  50  is set in the movable member  40  of the mounting/demounting unit  30 . The circuit board holding structure  59  may be formed from, for example, a material such as ABS resin or polystyrene (PS). The circuit board holding structure  59  is supported by the supply portion support structure  42  of the movable member  40  (shown in  FIG. 5C ) when the circuit board holding structure  59  is set in the movable member  40 . 
     As shown in  FIG. 9 , the circuit board holding structure  59  is in a recessed shape that is open on the +Z-axis direction side (side where the grip portion  54  is located). A −K1-axis direction side of the circuit board holding structure  59  is open to receive the contact mechanism  38 . The circuit board holding structure  59  includes a bottom (bottom face)  595  (shown in  FIG. 11 ), a first side wall portion  592  and a second side wall portion  593 . The bottom  595 , the first side wall portion  592  and the second side wall portion  593  define the recessed shape of the circuit board holding structure  59 . The first side wall portion  592  is a wall portion extended upward in the direction of gravity from a −K2-axis direction side portion of the bottom  595 . The second side wall portion  593  is a wall portion extended upward in the direction of gravity from a +K2-axis direction side portion of the bottom  595 . The first and the second side wall portions  592  and  593  connected with the bottom  595  are opposed to each other. 
     As shown in  FIG. 9 , the circuit board holding structure  59  includes a placement portion (placement surface)  594 . The circuit board  582  is mounted on the placement portion  594 . The placement portion  594  is located between the first and the second side wall portions  592  and  593 . The placement portion  594  is inclined such that its lower end is located on the −K1-axis direction side of its upper end. The placement portion  594  is inclined to face in a direction including a +Z-axis direction component and a −K1-axis direction component. The placement portion  594  is located on the +Z-axis direction side of the bottom  595 . 
     The circuit board holding structure  59  includes the first side wall portion  592  and the second side wall portion  593  that are respectively extended in the +Z-axis direction from the respective sides in the K2-axis direction of the bottom  595 . As shown in  FIG. 10  and  FIG. 15 , the first side wall portion  592  includes a groove  592   t  serving as a holding structure-side positioning element and a holding structure-side upper restriction portion  599   b . As shown in  FIG. 9  and  FIG. 15 , the second side wall portion  593  includes a groove  593   t  serving as a holding structure-side positioning element and a holding structure-side upper restriction portion  599   a.    
     As shown in  FIG. 15 , the holding structure-side upper restriction portion  599   a  (or  599   b ) is an end face on the upper side of the second side wall portion  593  (or the first side wall portion  592 ) in the direction of gravity. When the electrical connection structure  582  is connected with the apparatus-side terminals  381  of the electrical connection unit  38  (shown in  FIG. 5C ), the holding structure-side upper restriction portion  599   a  abuts on the apparatus-side upper restriction portion  377   a  (shown in  FIG. 6M ), while the holding structure-side upper restriction portion  599   b  abuts on the apparatus-side upper restriction portion  377   b  (shown in  FIG. 6M ). This configuration restricts the upward motion of the circuit board holding structure  59  in the direction of gravity. 
     As shown in  FIG. 13 , the two grooves  592   t  and  593   t  are provided on the respective sides in the K2-axis direction with the circuit board  582  placed therebetween. The two grooves  592   t  and  593   t  are respectively formed in an approximately rectangular parallelepiped shape. In the process of connecting the liquid container  50  with the printer  10 , the circuit board holding structure  59  is first supported by the board support structure  48  (shown in  FIG. 5C ). This configuration roughly positions the circuit board holding structure  59  and the circuit board  582  relative to the apparatus-side terminals  381  (shown in  FIG. 5C ). When the movable member  40  of the mounting/demounting unit  30  shown in  FIG. 5C  is moved in the −K1-axis direction, the apparatus-side board positioning structure  385  shown in  FIG. 5B  enters the groove  593   t  of the circuit board holding structure  59  (shown in  FIG. 13 ), while the apparatus-side board positioning structure  384  shown in  FIG. 5B  enters the groove  592   t  of the circuit board holding structure  59  (shown in  FIG. 13 ). This configuration determines the final positions of the circuit board holding structure  59  and the circuit board  582  relative to the apparatus-side terminals  381 . 
     As shown in  FIG. 17E , in the mounted state of the liquid container  50 , the second contact-side positioning structure  385  of the contact mechanism  38  (shown in  FIG. 5B ) is inserted into the groove  593   t  (second groove  5930 . The groove  593   t  includes a top face  593   ta , a side face  593   tb , a base end face  593   tc  and a bottom face  593   td . The top face  593   ta  and the bottom face  593   td  are opposed to each other in the Z-axis direction. The top face  593   ta  is located on the +Z-axis direction side, and the bottom face  593   td  is located on the −Z-axis direction side. The side face  593   td  forms a +K2-axis direction side face of the groove  593   t . The base end face  593   tc  forms a +K1-axis direction side face of the groove  593   t.    
     As shown in  FIG. 17F , in the mounted state of the liquid container  50 , the first contact side positioning structure  384  of the contact mechanism  38  (shown in  FIG. 5B ) is inserted into the groove  592   t  (first groove  5920 . The groove  592   t  has the same configuration as that of the groove  593   t . The groove  592   t  includes a top face  592   ta , a side face  592   tb , a base end face  592   tc  and a bottom face  592   td . The top face  592   ta  and the bottom face  592   td  are opposed to each other in the Z-axis direction. The top face  592   ta  is located on the +Z-axis direction side, and the bottom face  592   td  is located on the −Z-axis direction side. The side face  592   td  forms a −K2-axis direction side face of the groove  592   t . The base end face  592   tc  forms a +K1-axis direction side face of the groove  592   t.    
     When the circuit board  582  comes into contact with the electrical connection structure  382  (shown in  FIG. 5B ) to be electrically connected with the electrical connection structure  382 , the circuit board  582  is positioned relative to the electrical connection structure  382  in the first direction (K1 axis direction) and in directions (Z-axis direction and K2-axis direction) intersecting with the first direction as described below. 
     When the liquid container  50  is set in the movable member  40  and is pressed in the connecting direction (in the −K1-axis direction), the apparatus-side board positioning structures  384  and  385  (shown in  FIG. 6P  and  FIG. 6Q ) start insertion into the grooves  592   t  and  593   t . This causes the first restriction element  385   a  (shown in  FIG. 6T ) to abut on the top face  593   ta  (shown in  FIG. 17E ), while causing the first restriction element  384   a  (shown in  FIG. 6U ) to abut on the top face  592   ta  (shown in  FIG. 17F ). This restricts the motion of the circuit board holding structure  59  in the +Z-axis direction and thereby achieves positioning in the +Z-axis direction. This also causes the fourth restriction element  385   d  (shown in  FIG. 6T ) to abut on the bottom face  593   td  (shown in  FIG. 17E ), while causing the fourth restriction element  384   d  (shown in  FIG. 6U ) to abut on the bottom face  592   td  (shown in  FIG. 17F ). This restricts the motion of the circuit board holding structure  59  in the −Z-axis direction and thereby achieves positioning in the −Z-axis direction. Additionally, this causes the second restriction element  385   b  (shown in  FIG. 6T ) to abut on the side face  593   tb  (shown in  FIG. 17E ), while causing the second restriction element  384   b  (shown in  FIG. 6U ) to abut on the side face  592   tb  (shown in  FIG. 17F ). This restricts the motion of the circuit board holding structure  59  in the K2-axis direction and thereby achieves positioning in the K2-axis direction. 
     Further pressing the liquid container  50  in the connecting direction (−K1-axis direction) causes the third restriction element  385   c  (shown in  FIG. 6T ) to abut on the base end face  593   tc  (shown in  FIG. 17E ), while causing the third restriction element  384   c  (shown in  FIG. 6U ) to abut on the base end face  592   tc  (shown in  FIG. 17F ). This restricts the motion of the circuit board holding structure  59  in the first direction (in the −K1-axis direction) and thereby achieves positioning in the first direction. This configuration enables the circuit board  582  and the electrical connection structure  382  to come into contact with each other with high accuracy at predetermined positions. 
     As shown in  FIG. 11 , the restriction element  597  is provided on the bottom  595 . The restriction element  597  is a projection protruded outward (in the −Z-axis direction) from the bottom  595 . The restriction element  597  abuts on the apparatus-side restriction element  489  of the movable member  40  (shown in  FIG. 6K ), so as to restrict the motion of the circuit board holding structure  59  in the opposite direction (+K1 axis direction) opposite to the first direction (−K1-axis direction). 
     As shown in  FIG. 17B , a boss groove  584  is formed on a +Z-axis direction side upper end  586  of the circuit board  582 , and a boss hole  585  is formed on a −Z-axis direction side lower end  587  of the circuit board  582 . The circuit board  582  is fixed to the placement portion  594  using the boss groove  584  and the boss hole  585 . 
     As shown in  FIGS. 17B and 17C , the circuit board  582  includes a liquid container-side terminal group  580  provided on a surface  582   fa  and a storage device  583  provided on a rear face  582   fb . The surface  582   fa  and the rear face  582   fb  are planes. 
     The liquid container side terminal group  580  consists of nine terminals  581 A to  581 I. The storage device  583  stores, for example, information regarding the liquid container  50  (for example, the remaining amount of ink and the color of ink). 
     As shown in  FIG. 17B , the nine liquid container-side terminals  581 A to  581 I are respectively formed in an approximately rectangular shape and are arranged in two lines Ln 1  and Ln 2  at different positions in the Z-axis direction. The lines Ln 1  and Ln 2  are parallel to the K2-axis direction. 
     The liquid container-side terminals  581 A to  581 I respectively have contacts cp arranged in their centers to come into contact with the corresponding apparatus-side terminals  381 A to  381 I (shown in  FIG. 6V ). The above lines Ln 1  and Ln 2  may be regarded as lines formed by a plurality of the contacts cp. When there is no need to distinguish among the nine liquid container-side terminals  581 A to  581 I, these are expressed by a reference sign “ 581 ”. 
     As shown in  FIG. 17D , in the mounted state of the liquid container  50 , the surface  582   fa  with the plurality of contacts cp placed thereon is inclined such that the lower end  587  is located on the first direction side (on the −K1-axis direction side or connecting direction side) of the upper end  586 . A plane (contact plane) TP defined by the plurality of contacts cp is inclined such that the lower side is located on the first direction side of the upper side. The surface  582   fa  and the plane TP are inclined to face in a direction including a +Z-axis direction component (upward component in the direction of gravity) and a −K1-axis direction component (first direction component). 
     A-6. Method of Mounting Liquid Container  50  to Mounting/Demounting Unit  30   
       FIG. 18  is a diagram illustrating the state that the liquid container  50  is set in the mounting/demounting unit  30 .  FIG. 19  is an F 18 -F 18  partial sectional view of  FIG. 18 .  FIG. 20  is a diagram illustrating the state that the liquid container  50  is mounted to the mounting/demounting unit  30 .  FIG. 21  is an F 20 -F 20  partial sectional view of  FIG. 20 . The state of the mounting/demounting unit  30  shown in  FIG. 18  and  FIG. 19  is the first state like the state of  FIG. 5 . The state of the mounting/demounting unit  30  shown in  FIG. 20  and  FIG. 21  is the second state like the state of  FIG. 6 . 
     As shown in  FIG. 19 , the liquid container  50  is mounted to the mounting/demounting unit  30  by two operations, i.e., operation of moving the liquid container  50  in a setting direction (setting operation or first operation) and operation of moving the liquid container  50  in a connecting direction (connecting operation or second operation). The setting direction is a direction including a downward component in the direction of gravity (−Z-axis direction component). According to this embodiment, the setting direction is downward in the direction of gravity. The connecting direction is a direction including a horizontal direction component (K1-axis direction component). According to this embodiment, the connecting direction is the −K1-axis direction (first direction) that is the horizontal direction. 
     When the mounting/demounting unit  30  is in the first state, the user sets the liquid container  50  in the movable member  40  of the mounting/demounting unit  30 . More specifically, the user holds the grip portion  54  in such an orientation that the operation member  53  is located above the liquid container body  52  in the direction of gravity. As shown in  FIGS. 18 and 19 , the user places the container body-side support structure  56  of the liquid container  50  in the supply portion support structure  42 , while placing the circuit board holding structure  59  in the board support structure  48 . 
     After setting the liquid container  50  in the movable member  40 , as shown by an arrow F in  FIG. 19 , the user presses the pressed portion  545  in the −K1-axis direction. This moves the liquid container  50  and the movable member  40  in the connecting direction (−K1-axis direction). 
     As shown in  FIG. 21 , when the mounting/demounting unit  30  is in the second state, the liquid introduction portion  362  (shown in  FIG. 19 ) is inserted into (connected with inside of) the liquid supply portion  57 . In the second state, the terminal  581  of the circuit board  582  (shown in  FIG. 13 ) come into contact with the apparatus-side terminals  381  of the electrical connection structure  382  (shown in  FIG. 5B ), so that the circuit board  582  and the electrical connection structure  382  are electrically connected. In the mounted state shown in  FIG. 21 , the protective member  354  is located above the electrical connection structure  582  of the liquid container  50  to cover the upper portion of (above) the electrical connection structure  582 . In the state of  FIG. 21 , the electrical connection structure  582  is located on the +K2-axis direction side of the liquid supply portion  57 . 
     The above expression of “in the process of connecting the liquid container  50  with the mounting/demounting unit  30  (printer  10 )” denotes at least part of a time period from the time when the user holds the operation member  53  and starts the setting operation to the time when connection of the liquid container  50  with the printer  10  is completed by the connecting operation. According to this embodiment, part of the time period is a time period from the time when the liquid container  50  is set in the movable member  40  and is slightly moved in the connecting direction to the time when the connection is completed. As shown in  FIGS. 18 to 21 , the movable member  40  supports the liquid container  50  such that the liquid supply portion  57  of the liquid container  50  is located above the liquid container body  52  in the direction of gravity (on the +Z-axis direction side). 
     A-7 Connecting Timings of Respective Components 
       FIG. 22  is a first diagram illustrating connection timing.  FIG. 23  is an F 22 A-F 22 A partial sectional view of  FIG. 22 .  FIG. 24  is an F 22 B-F 22 B partial sectional view of  FIG. 22 .  FIG. 25  is a second diagram illustrating connection timing.  FIG. 26  is an F 25 A-F 25 A partial sectional view of  FIG. 25 .  FIG. 27  is an F 25 B-F 25 B partial sectional view of  FIG. 25 .  FIG. 22  is a first diagram prior to completion of mounting the liquid container  50 .  FIG. 25  is a second diagram prior to completion of mounting the liquid container  50 . 
     As shown in  FIGS. 23 and 24 , pressing the liquid container  50  in the connecting direction (−K1-axis direction or first direction) causes the liquid supply portion  57  to start connecting with the liquid introduction portion  362 , before causing the circuit board  582  (more specifically, the terminals  581  of the circuit board  582 ) to start connecting (coming into contact) with the apparatus-side terminals  381 . For the purpose of better understanding, an area where the liquid supply portion  57  starts connecting with the liquid introduction portion  362  is shown by a reference sign “R 23 ” in  FIG. 23 . 
     As shown in  FIGS. 26 and 27 , further pressing the liquid container  50  in the connecting direction causes the terminals  581  of the circuit board  582  to start coming into contact with the apparatus-side terminals  381 . 
     A-8. Relationship of Respective Components of Printer  10  and Liquid Container  50   
     A-8-1. Supporting in Connecting 
       FIG. 28  is a side view illustrating the state that the liquid container  50  is set in the movable member  40  included in the mounting/demounting unit  30 .  FIG. 29  is a front view illustrating the state that the liquid container  50  is set in the movable member  40  included in the mounting/demounting unit  30 .  FIG. 30  is an F 28 -F 28  sectional view of  FIG. 28 .  FIG. 31  is an F 29 -F 29  sectional view of  FIG. 29 .  FIG. 32  is a side view illustrating the state that mounting (connection) of the liquid container  50  to (with) the mounting/demounting unit  30  is completed.  FIG. 33  is an F 32 -F 32  sectional view of  FIG. 32 . The state of the mounting/demounting unit  30  shown in  FIG. 28  is the first state like the state of  FIG. 5 . The state of the mounting/demounting unit  30  shown in  FIG. 32  is the second state like the state of  FIG. 6 . 
     As shown in  FIG. 30 , in the state that the liquid container  50  is set in the movable member  40 , the liquid supply unit  55  and the substrate unit  58  support the liquid container body  52  such that the liquid supply unit  55  and the substrate unit  58  are located above the liquid container body  52  in the direction of gravity (on the +Z-axis direction side). As shown in  FIG. 30 , a bottom  569  of the container body-side support structure  56  abuts on the third support surface  404  of the supply portion support structure  42 . This restricts the downward motion of the liquid container  50  in the direction of gravity (in the −Z-axis direction). This configuration supports the −K2-axis direction side of the liquid container body  52 . 
     As shown in  FIG. 33 , as in the state that the liquid container  50  is set in the movable member  40 , in the state that the liquid container  50  is connected with the mounting/demounting unit  30  (in the mounted state), the liquid supply unit  55  and the substrate unit  58  support the liquid container body  52  such that the liquid supply unit  55  and the substrate unit  58  are located above the liquid container body  52  in the direction of gravity (on the +Z-axis direction side). More specifically, the bottom  595  of the circuit board holding structure  59  abuts on a bottom  357  of the stationary member  35 . This restricts the downward motion of the liquid container  50  in the direction of gravity (in the −Z-axis direction). The bottom  569  of the container body-side support structure  56  abuts on the third support surface  404  of the supply portion support structure  42 . This restricts the downward motion of the liquid container  50  in the direction of gravity (in the −Z-axis direction). The liquid supply unit  55  and the substrate unit  58  restrict the downward motion of the liquid container  50  in the direction of gravity in this manner and support the liquid container  50 . The circuit board holding structure  59  starts abutting on the bottom  357  of the stationary member  35  during a time period from the time when the liquid container  50  is set in the movable member  40  and is moved in the connecting direction to the time when connection is completed. 
     As shown in  FIGS. 30 and 33 , duration rotation in the direction of an arrow R 30 , the bottom  595  of the circuit board holding structure  59  abuts on an apparatus-side rotation restriction element  487  of the movable member  40 . This restricts rotation of the circuit board holding structure  59  about the liquid supply portion  57  in the direction of the arrow R 30 . The bottom  595  is thus also called rotation restriction element  595 . 
     A-8-2. Positioning of Liquid Supply Portion  57  and Liquid Introduction Portion  362   
       FIG. 34  is an F 25 A-F 25 A partial enlarged view of  FIG. 25 .  FIG. 35  is a diagram illustrating positioning. 
     As shown in  FIG. 34 , for example, when the liquid supply portion  57  is located above the designed position of the liquid introduction portion  362  in the direction of gravity, the first supply portion positioning structure  364   a  abuts on the first container-side positioning structure  577   a , so as to position the liquid supply portion  57  in the +Z-axis direction. 
     As shown in  FIG. 35 , in the process of connecting the liquid container  50  with the mounting/demounting unit  30 , the positioning structures  577  provided around the liquid supply portion  57  enter inside of the positioning structures  364  provided around the liquid introduction portion  362 . When the liquid supply portion  57  is misaligned relative to the liquid introduction portion  362 , the positioning structure  577  abuts on the supply portion positioning structure  364 , so as to finely adjust the position of the liquid supply portion  57  relative to the liquid introduction portion  362 . Accordingly the positioning structures  577  and the supply portion positioning structures  364  are members serving to position the liquid supply portion  57  relative to the liquid introduction portion  362  in a direction intersecting with the connecting direction (−K1-axis direction). 
     A-9. Details of Liquid Introduction Mechanism  36  and Displacement Mechanism (Aligning) of Liquid Introduction Portion  362   
       FIG. 36  is an F 5 B-F 5 B partial sectional view of  FIG. 5B .  FIG. 37  is a diagram illustrating the liquid introduction portion  362  viewed from the −K2-axis direction side.  FIG. 38  is a top view illustrating the mounting/demounting unit  30 .  FIG. 39  is an F 38 -F 38  sectional view.  FIG. 40  is a diagram illustrating a displacement mechanism. The liquid container  50  is also illustrated in  FIG. 36  and  FIG. 37  for the purpose of better understanding. 
     As shown in  FIG. 36  and  FIG. 37 , the liquid introduction mechanism  36  includes a liquid flow portion  369  configured to form a flow path through which ink contained in the liquid container  50  is flowed to the printer  10 . The liquid flow portion  369  includes the liquid introduction portion  362 , the liquid introduction main body  368  and a connecting flow path portion  374  arranged in this sequence from the upstream side in the flow direction of ink from outside toward the printer  10 . In the description below, the “upstream side” and the “downstream side” are defined on the basis of the flow direction of ink from outside (liquid container  50 ) toward the printer  10 . The liquid flow portion  369  forms a flow path parallel to the center axis CT on the upstream side and forms a downward flow path in the direction of gravity on the downstream side. The liquid flow portion  369  may be regarded as the “liquid introduction portion  362 ”. 
     A liquid introducing hole  362 H is formed on an upstream side end of the liquid introduction portion  362  and causes ink from outside to be flowed into a flow path in the liquid introduction portion  362 . A downstream side end of the liquid introduction portion  362  is connected with the liquid introduction main body  368 . The liquid introduction portion  362  and the liquid introduction main body  368  form a flow path parallel to a center axis CL. The liquid introduction main body  368  may be regarded as part of the liquid introduction portion  362 . In this sense, the liquid introduction main body  368  forms a downstream side end of the liquid introduction portion  362 . 
     An upstream side end of the connecting flow path portion  374  is connected with the liquid introduction main body  368 , and a downstream side end is connected with the liquid flow tube  320 . The connecting flow path portion  374  forms a bent flow path. More specifically, the connecting flow path portion  374  forms a flow path parallel to the center axis CL and a downward flow path in the direction of gravity. The connecting flow path portion  374  includes a flow path forming portion  374 A configured to form a flow path and a connection structure  374 B configured to join the liquid flow tube  320  with the flow path forming portion  374 A in the airtight manner. The flow path forming portion  374 A and the connection structure  374 B are formed by two-color molding. This configuration enables the flow path forming portion  374 A and the connection structure  374 B to be readily formed by using different materials. 
     The liquid flow portion  369  (liquid introduction portion  362 ) is insert molded in the state that one end of the liquid flow tube  320  is inserted into the connection structure  374 B of the liquid flow portion  362 . More specifically, the connection structure  374 B and the flow path forming portion  374 A are molded components, and the liquid flow tube  320  is an insert component. More specifically, after the flow path forming portion  374 A and the liquid flow tube  320  are connected, the connection structure  374 B is injection molded to cover the periphery of the connecting region. Insert molding of the liquid flow tube  320  in the liquid flow portion  369  enables the connecting region to be made airtight by the connection structure  374 B. This configuration reduces the possibility that ink is leaked outside from the connecting region between the liquid flow tube  320  and the liquid flow portion  369 . In the configuration that the liquid flow tube  320  is connected with the connection structure  374 B and is fixed by means of a spring, there is a possibility that a portion fixed by the spring creeps to be cracked and cause leakage of the liquid. The liquid supply device  20  of this configuration, however, reduces the possibility of such leakage of the liquid. The other end (not shown) of the liquid flow tube  320  that is located on the printer  10 -side is also insert molded in the state that the other end is inserted into a connection structure. 
     As described above, the liquid flow portion  369  has an upstream-side introduction portion that includes a leading edge (upstream side end)  362   a  that is to be connected with the liquid lead-out portion  57  and forms a flow path parallel to the first direction (−K1-axis direction). The liquid flow portion  369  also has a downstream-side introduction portion that includes a downstream side end that is to be connected with the liquid flow tube  320  and is extended from the upstream-side introduction portion downward in the direction of gravity (in the −Z-axis direction). The liquid flow portion  369  includes the downstream-side introduction portion that is extended in the direction intersecting with the first direction (downward in the direction of gravity). This configuration suppresses size expansion of the liquid supply device  20  in the first direction. 
     As shown in  FIG. 36 , a recess  374   r  serving as a spring receiver to receive the other end of the coil spring  367  is formed on the opposite side of the connecting flow path portion  374  (connection structure base end  374   e ) that is opposite to the side where the liquid introduction main body  368  is located in the direction parallel to the center axis CL (center axis CL direction). One end of the coil spring  367  abuts on the wall surface of the printer  10  (for example, the apparatus third surface  106  shown in  FIG. 2 ). The coil spring  367  presses the liquid flow portion  369  toward the leading edge  362   a  of the liquid introduction portion  362  (in the +K1-axis direction or in the direction toward the liquid supply portion  57 ). With regard to the liquid introduction portion  362 , a direction from the leading edge  362   a  toward a base end  362   b  (or to the connection structure base end  374   e ) is the −K1-axis direction (connecting direction). 
     As shown in  FIG. 36  and  FIG. 40 , the connection structure base end  374   e  includes restriction elements  376  that are protruded outward in a plane direction perpendicular to the center axis CL direction. As shown in  FIG. 36 , the restriction elements  376  are placed in an inner housing space  366 H of the fixation structure  366 . The restriction elements  376  abut on a wall portion  366 B configured to define and form the inner housing space  366 H. This configuration restricts the motion of the liquid flow portion  369  toward the leading edge  362   a  by the coil spring  367 . 
     As shown in  FIG. 40 , three restriction elements  376  are provided at approximately fixed intervals in the circumferential direction of the connection structure base end  374   e  having an approximately circular section. More specifically, the restriction elements  376  include a first restriction element  376 A, a second restriction element  376 B and a third restriction element  376 C as shown in  FIGS. 39 and 40 . The restriction elements  376  are arranged with some backlash (clearance) relative to the wall portion configured to define and form the inner housing space  366 H in a direction perpendicular to the center axis CL direction (K1-axis direction) (direction parallel to the plane defined by the Z-axis direction and the K2-axis direction). The liquid flow portion  369  is accordingly configured to be displaceable by the coil spring  367  and the fixation structure  366  fixed to the stationary member  35  in the direction intersecting with the first direction (−K1-axis direction) (direction parallel to the plane defined by the Z-axis direction and the K2-axis direction). 
     A-10. Displacement Mechanism of Movable Member  40   
       FIG. 41  is a top view illustrating the mounting/demounting unit  30  and the liquid container  50 .  FIG. 42  is a first diagram corresponding to an F 41 -F 41  partial sectional view.  FIG. 43  is a second diagram corresponding to the F 41 -F 41  partial sectional view.  FIG. 44  is a third view corresponding to the F 41 -F 41  partial sectional view. In  FIGS. 42 to 44 , the positions of the movable member  40  and the liquid container  50  are changed relative to the stationary member  35 .  FIG. 42  is a diagram illustrating the state that the liquid container  50  is set in the movable member  40  in the first state that the movable member  40  is protruded outward relative to the stationary member  35 .  FIG. 43  is a diagram illustrating the state that the movable member  40  is pressed in the connecting direction (−K1-axis direction) and causes the liquid supply portion  57  to start connecting with the liquid introduction portion  362 .  FIG. 44  is a diagram illustrating the mounted state of the liquid container  50 . 
     As shown in  FIG. 42 , the movable member  40  includes the guiding portion  465  in which the guide structure  365  of the liquid introduction main body  368  is inserted. The guiding portion  465  includes a first guiding portion  465 A and a second guiding portion  465 B. The first guiding portion  465 A is located on the first direction (−K1-axis direction) side of the second guiding portion  465 B. The second guiding portion  465 B is connected with the first guiding portion  465 A. The second guiding portion  465 B has a greater length in the direction of gravity (Z-axis direction) than the first guiding portion  465 A. Accordingly, as shown in  FIG. 42  and  FIG. 44 , a clearance between the second guiding portion  465 B and the guide structure  365  in the direction of gravity is larger than a clearance between the first guiding portion  465 A and the guide structure  365  in the direction of gravity. 
     As shown in  FIG. 42 , in the state that the movable member  40  is protruded most outward (+K1-axis direction) relative to the stationary member  35 , part of the guide structure  365  is placed in the first guiding portion  465 A. When the movable member  40  is pressed inward (in the first direction or −K1-axis direction) from the state shown in  FIG. 42 , the liquid supply portion  57  starts connecting with the liquid introduction portion  362  as shown in  FIG. 43 . At the start of connection, the guide structure  365  reaches the boundary between the first guiding portion  465 A and the second guiding portion  465 B. Further pressing the movable member  40  inward completes the connection of the liquid supply portion  57  with the liquid introduction portion  362  as shown in  FIG. 44 . 
     As described above, the guide structure  365  is located in the first guiding portion  465 A for a time period from the time when the liquid container  50  is set in the movable member  40  to the time when the liquid supply portion  57  starts connecting with the liquid introduction portion  362  (as shown in  FIGS. 42 and 43 ). The guide structure  365  is located in the second guiding portion  465 B for a time period from the time when the liquid supply portion  57  starts connecting with the liquid introduction portion  362  to the time when the connection is completed (as shown in  FIG. 43  and  FIG. 44 ). The guiding portion  465  of the movable member (first support assembly)  40  accordingly supports the liquid supply portion (liquid lead-out portion)  57  such that a side of the liquid supply portion  57  far from the liquid introduction portion  362  (first side) is displaceable by a greater degree in the direction intersecting with the first direction (in the Z-axis direction) than a side near to the liquid introduction portion  362  (second side). The “far side” is the supply connecting portion  573  (shown in  FIG. 9 ) that is the other end of the liquid supply portion  57 , and the “near side” is the liquid supply port  572  (shown in  FIG. 9 ) that is one end of the liquid supply portion  57 . 
     The configuration of the guide structure  365  and the guiding portion  465  serving as the displacement mechanism facilitates positioning of the liquid supply portion  57  relative to the liquid introduction portion  362  at the start of connection of the liquid supply portion  57  with the liquid introduction portion  362 , and reduces restriction of the motion of the liquid supply portion  57  immediately before completion of the connection compared with that at the start of connection. This ensures smooth connection of the liquid supply portion  57  with the liquid introduction portion  362 . Prior to a start of connection, setting a small backlash enables the liquid supply portion  57  to be positioned with high accuracy relative to the liquid introduction portion  362 . After a start of connection, on the other hand, setting a large backlash enables the liquid introduction portion  362  to readily follow the motion of the liquid supply portion  57 . 
     In addition to the above configuration, the guiding portion  465  of the movable member (first support assembly)  40  may be configured to support the liquid supply portion (liquid lead-out portion)  57  such that the side of the liquid supply portion  57  far from the liquid introduction portion  362  is displaceable by a greater degree in the K2-axis direction than the side near to the liquid introduction portion  362 . This additional configuration may be implemented by, for example, making a clearance between the second guiding portion  465 B and the guide structure  365  in the K2-axis direction larger than a clearance between the first guiding portion  465 A and the guide structure  365  in the K2-axis direction. 
     A-11. Advantageous Effects 
     According to the embodiment described above, as shown in  FIG. 19 , the first support assembly  40  supports the liquid lead-out portion  57  such as to locate the liquid lead-out portion  57  above the liquid container body  52  in the direction of gravity and such as to move the liquid lead-out portion  57  along the first direction (−K1-axis direction) intersecting with the direction of gravity (Z-axis direction). This configuration reduces the possibility of failed connection of the liquid lead-out portion  57  with the liquid introduction portion  362  by the interference of the liquid container body  52 . According to the embodiment described above, as shown in  FIG. 35 , the positioning structures  364  are arranged around the liquid introduction portion  362 . This configuration enables the liquid lead-out portion  57  to be positioned relative to the liquid introduction portion  362  in the direction intersecting with the first direction (−K1-axis direction) (direction parallel to the plane defined by the Z-axis direction and the K2-axis direction). This ensures smooth connection of the liquid lead-out portion  57  with the liquid introduction portion  362 . 
     According to the above embodiment, as shown in  FIGS. 36, 39 and 40 , the second support structure  366  supports the liquid introduction portion  362  such that the liquid introduction portion  362  is displaceable in the direction intersecting with the first direction. This configuration enables the liquid introduction portion  362  to be displaced following the motion of the liquid lead-out portion  57  in the process of connecting the liquid introduction portion  362  with the liquid lead-out portion  57 . This ensures smoother connection of the liquid lead-out portion  57  with the liquid introduction portion  362 . 
     According to the above embodiment, as shown in  FIG. 36 , the liquid introduction portion  362  is pressed by the coil spring  367  in the direction toward the liquid lead-out portion  57 . This configuration reduces the possibility that the liquid lead-out portion  57  is dropped off from the liquid introduction portion  362  in the mounted state of the liquid container  50 . In other words, this configuration reduces the possibility of failed connection of the liquid introduction portion  362  with the liquid lead-out portion  57 . 
     According to the above embodiment, as shown in  FIG. 36 , the liquid introduction mechanism  36  including the liquid supply connection structure  362  (liquid introduction portion  362 ) is supported by the outer wall (for example, the apparatus third surface  106  shown in  FIG. 4 ) via the fixation structure  366  and the stationary member  35 . This configuration facilitates connection of the liquid container  50  with the liquid supply connection structure  362 , compared with the configuration that the liquid supply connection structure  362  is placed inside of the printer  10 . This configuration also suppresses size expansion of the printer  10  and provides a large space for the liquid container  50  placed therein, compared with the configuration that the liquid supply connection structure  362  is placed inside of the printer  10 . This provides the large capacity of the liquid container body  52  of the liquid container  50  and accordingly enables a large amount of liquid to be contained in the liquid container  50 . This configuration shortens the flow path of ink from the liquid container  50  to the printer  10  (liquid supply passage), compared with the external configuration that the liquid container  50  is placed at a location away from the printer  10 . This accordingly shortens a time period required for the ink contained in the liquid container  50  to reach the printer  10 . This also suppresses the ink component from being vaporized through the liquid supply passage to change the properties of ink. This additionally reduces the flow resistance in the liquid supply passage and thereby reduces the power required for supplying ink from the liquid container  50  to the printer  10  (for example, the power of a pump used to suck ink). 
     According to the above embodiment, as shown in  FIG. 6A  and  FIG. 6J , the contact mechanism  38  including the apparatus-side electrical connection structure  382  is supported by the outer wall (for example, the apparatus third surface  106  shown in  FIG. 4 ) via the sheet metal  323  and the stationary member  35 . This configuration facilitates connection of the apparatus-side electrical connection structure  382  with the container-side electrical connection structure  582  (circuit board  582 ), compared with the configuration that the apparatus-side electrical connection structure  382  is placed inside of the printer  10 . 
     According to the above embodiment, as shown in  FIG. 5B , the liquid supply connection structure  362  and the apparatus-side electrical connection structure  382  are arranged side by side in the K2-axis direction. More specifically, the liquid supply connection structure  362  and the apparatus-side electrical connection structure  382  are arranged adjacent to each other in the K2-axis direction. In other words, the liquid supply connection structure  362  and the apparatus-side electrical connection structure  382  are arranged next to each other such as to be visible simultaneously for the user. The user can thus simultaneously observe the liquid supply connection structure  362  and the apparatus-side electrical connection structure  382  and connect the corresponding portions (the liquid lead-out portion  57  and the circuit board  582 ) of the liquid container  50 . This improves the operability in mounting the liquid container  50  to the printer  10 . The term “adjacent” in the description hereof means that two members are arranged next to each other but do not necessarily adjoin to each other. Accordingly the two members may not be in contact with each other. 
     According to the above embodiment, as shown in  FIG. 5A , the liquid supply device  20  includes the liquid container holder  22  that has the bottom face  27  and the openable and closable top. Even if ink is leaked out from the liquid supply connection structure  362  during attachment or detachment of the liquid supply portion  57  to or from the liquid supply connection structure  362 , the leaked ink is accumulated on the bottom face  27 . This reduces the possibility that the outside of the liquid supply device  20  is stained with ink. The top of the liquid container holder  22  is opened and closed only when needed, for example, for mounting and demounting the liquid container  50  to and from the printer  10 . The liquid container  50  is accordingly protected by the liquid container holder  22  in the ordinary state, for example, during use of the printer  10 . This reduces the possibility that the liquid container  50  is damaged. The liquid supply connection structure  362  is placed inside of the liquid container holder  22 . This reduces the possibility that the liquid supply connection structure  362  is damaged. 
     According to the above embodiment, as shown in  FIG. 10  and  FIG. 18 , the holding structure  59  supports the container-side electrical connection structure  582  to be located above the liquid container body  52  (on the upper side in the direction of gravity) when the liquid container  50  is connected with the printer  10 . Even in the state that the liquid container body  52  hangs down in the direction of gravity by the dead weight (in the free state), the holding structure  59  supports the container-side electrical connection structure  582 , such as to locate the container-side electrical connection structure  582  in the designed range. This configuration ensures favorable electrical connection between the container-side electrical connection structure  582  and the apparatus-side electrical connection structure  382 . 
     According to the above embodiment, as shown in  FIG. 17D , the contact plane TP is inclined such that the lower side is located on the first direction side (−K1-axis direction side) of the upper side. The surface  62   fa  of the terminal holder  62  is accordingly inclined such that the upper side is protruded more than the lower side in the opposite direction (+K1-axis direction) to the first direction as shown in  FIG. 24 . In other words, the surface  62   fa  of the terminal holder  62  is arranged to cover over the contacts cp of the circuit board  582 . This configuration reduces the possibility that impurity such as dust adheres to the electrical connection structure  382  (for example, the surface  62   fa  or the apparatus-side terminals  381 ). This accordingly ensures more favorable electrical connection between the container-side electrical connection structure  582  and the apparatus-side electrical connection structure  382 . 
     According to the above embodiment, as shown in  FIG. 6K  and  FIG. 11 , the holding structure  59  includes the restriction element  597  that abuts on the first support assembly  40  so as to restrict the motion of the holding structure  59  in the opposite direction (+K1-axis direction) to the first direction. In the mounted state, an external force in the +K1-axis direction may be applied to the holding structure  59  of the liquid container  50 . This external force may be, for example, the pressing force of the coil spring  387  shown in  FIG. 6J  or the elastic force of the apparatus-side terminals  381  shown in  FIG. 6V . Applying such an external force in the +K1-axis direction to the holding structure  59  is likely to move the holding structure  59  in the +K1-axis direction and cut off the electrical connection between the container-side electrical connection structure  582  and the apparatus-side electrical connection structure  382 . The restriction element  597 , however, serves to restrict the motion of the holding structure  59  in the +K1-axis direction and thereby stably maintains the electrical connection between the container-side electrical connection structure  582  and the apparatus-side electrical connection structure  382 . 
     According to the above embodiment, as shown in  FIG. 30  and  FIG. 33 , the holding structure  59  includes the rotation restriction element  595  that abuts on the first support assembly  40  so as to restrict rotation of the holding structure  59  in the direction of the arrow R 30 . This configuration restricts rotation of the holding structure  59  and thereby further stably maintains the electrical connection between the container-side electrical connection structure  582  and the apparatus-side electrical connection structure  382 . 
     According to the above embodiment, as shown in  FIG. 6A , the printer  10  includes the first support assembly  40  and the stationary member  35  to which the electrical connection unit  38  including the liquid introduction portion  362  and the apparatus-side electrical connection structure  382  is attached. As shown in  FIG. 6R , the apparatus-side electrical connection structure  382  is attached such as to be displaceable in the direction intersecting with the first direction (−K1-axis direction) (direction parallel to the plane defined by the Z-axis direction and the K2-axis direction). As shown in  FIG. 17E  and  FIG. 17F , the holding structure  59  is configured to be connectable with the apparatus-side electrical connection structure  382  to which the container-side electrical connection structure  582  is attached in a displaceable manner. The holding structure  59  has the grooves  593   t  and  592   t  configured to receive the apparatus-side board positioning structures  384  and  385  (shown in  FIG. 6T ) of the electrical connection unit  38  as shown in  FIG. 17E  and  FIG. 17F . This configuration allows the apparatus-side electrical connection structure  382  to be displaced following the motion of the holding structure  59  in the process of connecting the container-side electrical connection structure  582  with the apparatus-side electrical connection structure. This ensures favorable electrical connection between the container-side electrical connection structure  582  and the apparatus-side electrical connection structure  382 . 
     According to the above embodiment, as shown in  FIG. 17E  and  FIG. 17F , the holding structure  59  of the liquid container  50  abuts on the apparatus-side board positioning structures  384  and  385  (shown in  FIG. 6T ) in the process of connecting the container-side electrical connection structure  582  with the apparatus-side electrical connection structure  382 . This configuration positions the container-side electrical connection structure  582  relative to the apparatus-side electrical connection structure  382  and thereby ensures favorable electrical connection between the apparatus-side electrical connection structure  382  and the container-side electrical connection structure  582 . This configuration, for example, makes the apparatus-side electrical connection structure  382  and the container-side electrical connection structure  582  unlikely to be affected by the load of a downward component in the direction of gravity generated by the dead weight of the liquid container body  52 . This reduces the possibility of failed electrical connection between these connection structures  382  and  582 . 
     According to the above embodiment, as shown in  FIG. 13 , the holding structure-side positioning elements  592   t  and  593   t  are provided on the respective sides with the container-side electrical connection structure  582  placed therebetween. As shown in  FIG. 6T , the apparatus-side board positioning structures  384  and  385  are provided on the respective sides with the apparatus-side terminals  381  of the apparatus-side electrical connection structure  382  placed therebetween. This configuration reduces the possibility that the container-side electrical connection structure  582  (or the apparatus-side electrical connection structure  382 ) is inclined, compared with the configuration that has only the holding structure-side positioning elements  592   t  and  593   t  (or has only the apparatus-side board positioning structures  384  and  385 ) provided only one of the container-side or the apparatus-side. 
     According to the above embodiment, as shown in  FIG. 15 , the holding structure  59  includes the holding structure-side upper restriction portions  599   a  and  599   b . As shown in  FIG. 6M , the fixation structure  37  includes the apparatus-side upper restriction portions  377   a  and  377   b . When the container-side electrical connection structure  582  is connected with the apparatus-side electrical connection structure  382 , the holding structure-side upper restriction portions  599   a  and  599   b  of the holding structure  59  abut on the apparatus-side upper restriction portions  377   a  and  377   b  of the fixation structure  37 . This restricts the upward motion of the holding structure  59  in the direction of gravity. This accordingly ensures more favorable electrical connection between the container-side electrical connection structure  582  and the apparatus-side electrical connection structure  382 . According to the above embodiment, such restriction starts prior to start of positioning by the apparatus-side board positioning structures  384  and  385  (shown in  FIG. 6T ) and the holding structure-side positioning elements  593   t  and  592   t  (shown in  FIGS. 17E and 17F ) of the holding structure  59 . This roughly positions the apparatus-side board positioning structures  384  and  385  provided as the projections relative to the holding structure-side positioning elements  593   t  and  592   t  provided as the grooves. This accordingly enables the apparatus-side board positioning structures  384  and  385  to be securely inserted into the holding structure-side positioning elements  593   t  and  592   t.    
     According to the above embodiment, the protective member (cover portion)  354  is used to cover over the apparatus-side electrical connection structure  382  as shown in  FIG. 5C . This cover portion  354  is arranged to cover over the holding structure  59  and the circuit board  582  of the liquid container  50  when the container-side electrical connection structure  582  is connected with the apparatus-side electrical connection structure  382  (for example, in the mounted state). This reduces the possibility that impurity such as dust falls down from above the apparatus-side electrical connection structure  382  and adheres to the apparatus-side electrical connection structure  382 . This accordingly ensures more favorable electrical connection between the container-side electrical connection structure  582  and the apparatus-side electrical connection structure  382 . 
     A-12. Another Preferable Embodiment 
       FIG. 45  is a diagram illustrating a preferable embodiment. The liquid supply device  20  may further include a liquid flow tube  320  and a holding member  329 . The holding member  329  is configured to hold the liquid flow tube  320 . According to this embodiment, the holding member  329  includes a pair of ribs  329 A and  329 B provided on the outer wall of the printer  10  (for example, the apparatus third surface  106  shown in  FIG. 2 ). The liquid flow tube  320  is placed and is thereby held between the pair of ribs  329 A and  329 B. More specifically, the holding member  329  holds the liquid flow tube  320  such that an upstream end portion of the liquid flow tube  320  from an upstream end  320   u  to a position  320   p  where the holding member  329  is located is extended along the direction of gravity (Z-axis direction) in the flow direction of ink from the liquid introduction portion  362  to the printer  10 . Accordingly the holding member  329  is located immediately below the connecting flow path portion  374 . 
     Even in an arrangement that a downstream side of the liquid flow tube  320  is bent from its upstream end portion, this configuration enables the upstream end portion to be maintained in the shape along the direction of gravity. Even when a reaction force is produced by bending the downstream side of the liquid flow tube  320 , the holding member  329  serves to receive the reaction force. For example, this reduces the possibility that another member of the liquid supply device (for example, second support structure  366 ) is affected by the downstream side of the liquid flow tube. In a configuration of the liquid supply device  20  without the holding member  329 , bending the upstream side of the liquid flow tube  320  is likely to cause a failure in placing the restriction elements  376  at the designed positions in the second support structure  366  by the effect of the reaction force of the liquid flow tube  320 . The reaction force of the liquid flow tube  320  applied to the second support structure  366  is also likely to cause deformation of the second support structure  366 . 
     The holding member  329 , however, maintains the upstream end portion of the liquid flow tube  320  in the shape along the direction of gravity. More specifically, even when the reaction force is produced in the upstream end portion by bending the downstream side of the liquid flow tube  320  from the upstream end portion, the holding member  329  receives the produced reaction force. This configuration enables the restriction elements  376  to be placed at the designed positions in the second support structure  366  with high accuracy. This enables the displacement mechanism using the second support structure  366  of the liquid flow portion  369  to work in the designed range. The holding member  329  is not limited to the ribs but may be any shape that can hold the liquid flow tube  320 . For example, the holding member  329  may be a ring-shaped member. In this configuration, the liquid flow tube  320  is inserted through the ring shape. 
     In the embodiment, the substrate unit  58  is also called “container-side electrical connection structure  58 ”. The circuit board holding structure  59  is also called “placement structure  59 ”. The holding structure-side positioning elements  592   t  and  593   t  are also called “container side electrical connection structure positioning elements  592   t  and  593   t ”. The holding structure-side upper restriction portions  599   a  and  599   b  are also called “container-side electrical connection structure upper restriction portions  599   a  and  599   b”.    
     B. Modifications 
     The disclosure is not limited to any of the embodiments and the examples described above but may be implemented by a diversity of other aspects without departing from the scope of the disclosure. Some of possible modifications are given below. 
     B-1. First Modification 
     In the above embodiment, the liquid container body  52  is formed from the flexible material. This is, however, not restrictive but any material may be employed to provide a liquid container body configured to contain a liquid inside thereof. For example, the liquid container body  52  may be formed partly from a flexible material or may be formed from a hard material that does not change the volume irrespective of consumption of the liquid. Forming at least part of the liquid container body  52  from the flexible material causes the volume of the liquid container body  52  to be changed with a change in amount of ink contained in the liquid container body  52 . 
     B-2. Second Modification 
     In the above embodiment, as shown in  FIG. 19 , the connecting direction of the liquid container  50  to the mounting/demounting unit  30  is the horizontal direction (K1-axis direction). This is, however, not restrictive, but the connecting direction may be any direction including a first direction component (−K1-axis direction component). For example, the connecting direction may be a direction including a −Z-axis direction component and a −K1-axis direction component. In this modification, the movable member  40  is also moved in a direction corresponding to the connecting direction of the liquid container  50 . 
     B-3. Third Modification 
     The disclosure is not limited to the inkjet printer or its liquid container  50  but is also applicable to any printing apparatus (liquid consuming apparatus) configured to eject any liquid other than ink and a liquid container configured to contain the liquid. For example, the disclosure may be applied to any of various liquid consuming apparatuses and their liquid containers given below: 
     (1) image recording apparatus such as a facsimile machine; 
     (2) color material ejection apparatus configured to eject a color material used for manufacturing color filters for an image display apparatus such as a liquid crystal display; 
     (3) electrode material ejection apparatus configured to eject an electrode material used for forming electrodes of, for example, an organic EL (electroluminescence) display and a field emission display (FED); 
     (4) liquid consuming apparatus configured to eject a bioorganic material-containing liquid used for manufacturing biochips; 
     (5) sample ejection apparatus used as a precision pipette; 
     (6) ejection apparatus of lubricating oil; 
     (7) ejection apparatus of a resin solution; 
     (8) liquid consuming apparatus for pinpoint ejection of lubricating oil on precision machines such as watches and cameras; 
     (9) liquid consuming apparatus configured to eject a transparent resin solution, such as an ultraviolet curable resin solution, onto a substrate in order to manufacture a hemispherical microlens (optical lens) used for, for example, optical communication elements; 
     (10) liquid consuming apparatus configured to eject an acidic or alkaline etching solution in order to etch a substrate or the like; and 
     (11) liquid consuming apparatus equipped with a liquid ejection head configured to eject a very small volume of droplets of any other liquid. 
     The “droplet” herein means the state of liquid ejected from the liquid consuming apparatus and may be in a granular shape, a teardrop shape or a tapered threadlike shape. The “liquid” herein may be any material ejectable from the liquid consuming apparatus. The “liquid” may be any material in the liquid phase. For example, liquid-state materials of high viscosity or low viscosity, sols, aqueous gels and other liquid-state materials including inorganic solvents, organic solvents, solutions, liquid resins and liquid metals (metal melts) are included in the “liquid”. The “liquid” is not limited to the liquid state as one of the three states of matter but includes solutions, dispersions and mixtures of the functional solid material particles, such as pigment particles or metal particles, solved in, dispersed in or mixed with a solvent. Typical examples of the liquid include ink described in the above embodiment and liquid crystal. The ink herein includes general water-based inks and oil-based inks, as well as various liquid compositions, such as gel inks and hot-melt inks. In an application that UV ink curable by UV radiation is contained in a liquid container body and is connected with the printer, the liquid container body is away from the placement surface. This reduces the likelihood that the UV ink is cured by transmission of heat from the placement surface to the liquid container body. 
     B-4. Fourth Modification 
       FIG. 46  is a diagram illustrating an example of preferable arrangement according to the embodiment.  FIG. 46  is a diagram of  FIG. 1  viewed from the +Z-axis direction (vertically downward). For the purpose of better understanding, the liquid containers  50 C,  50 M,  50 Y and  50 K placed inside of the cover members  22  are also illustrated. The printer  10  further includes a top face (upper wall)  101  on the +Z-axis direction side and an apparatus fourth surface (rear face, rear wall)  107  that is opposed to the apparatus first surface  102 . 
     The liquid containers  50 C,  50 M and  50 Y are connected with the second liquid supply device  20 B on the apparatus third surface (right side wall, first side wall)  106 -side. The liquid supply connection structure  362  and the apparatus-side electrical connection structure  382  of each of the mounting/demounting units  30 C,  30 M and  30 Y are arranged side by side in a predetermined direction Y 46   a . The liquid supply connection structure  362  and the apparatus-side electrical connection structure  382  of the mounting/demounting unit  30 K are arranged side by side in a predetermined direction Y 46   b . Multiple sets of the liquid supply connection structures  362  and the apparatus-side electrical connection structures  382  are accordingly arranged on the apparatus third surface  106 . The multiple sets are arranged in a direction in which the front face  102  and the rear face  107  are opposed to each other (i.e., in the X-axis direction). 
     The liquid container  50 K is connected with the first liquid supply device  20 A on the apparatus second surface (left side wall, apparatus second side wall)  104 -side. The liquid container  50 K has a larger capacity than those of the liquid containers  50 C,  50 M and  50 Y and is capable of containing a larger amount of ink. The magnitude relationship of ink capacity is provided by the following configuration according to the embodiment. The length of the liquid container  50 K in the predetermined direction Y 46   b  (width direction, K2-axis direction in  FIG. 7 ) is longer than the lengths of the liquid containers  50 C,  50 M and  50 Y in the predetermined direction Y 46   a  (width direction, K2-axis direction in  FIG. 7 ). According to this embodiment, the length of the liquid container  50 K in a direction (thickness direction, K1-axis direction in  FIG. 7 ) orthogonal to the predetermined direction Y 46   b  is longer than the lengths of the liquid containers  50 C,  50 M and  50 Y in a direction (thickness direction, K1-axis direction in  FIG. 7 ) orthogonal to the predetermined direction Y 46   a.    
     With regard to the clockwise direction from the apparatus third surface  106 , an angle between the apparatus third surface  106  and the predetermined direction Y 46   a  is defined as angle a1. The angle a1 is greater than 0 degree and smaller than 90 degrees. The predetermined direction Y 46   b  is parallel to the apparatus second surface  104 . Accordingly the liquid supply connection structure  362  and the apparatus-side electrical connection structure  382  supported on the apparatus second surface  104  are arranged side by side along a direction parallel to the apparatus second surface  104 . When the mounting/demounting units  30 C,  30 M and  30 Y are arranged on the apparatus second surface  104 -side, with regard to the counterclockwise direction from the apparatus second surface  104 , an angle a2 between the apparatus second surface  106  and the predetermined direction Y 46   a  is preferably greater than 0 degree and smaller than 90 degrees. 
     The angle a1 or the angle a2 is greater than 0 degree and smaller than 90 degrees as described above. This configuration suppresses expansion of the width in the left-right direction (Y-axis direction) in which the apparatus second surface  104  and the apparatus third surface  106  are opposed to each other. The liquid container  50 K having the larger capacity is arranged parallel to the apparatus second surface  104 . This configuration provides substantially equal spaces for mounting the liquid containers  50  on the apparatus second surface  104 -side and the apparatus third surface  106 -side across the printer  10 . 
     B-5. Fifth Modification 
       FIG. 47  is a diagram illustrating an electrical connector  50   a . In the above embodiment, the liquid container  50  includes the liquid containing bag  52  and the liquid supply portion  57  (shown in  FIG. 7  and  FIG. 9 ). The electrical connector  50   a  may be provided with omission of the liquid containing bag  52  and the liquid supply portion  57 . In other words, the electrical connector  50   a  is configured to exclude the liquid containing bag  52  and the liquid supply portion  57  from the configuration of the liquid container  50  and otherwise has the same configuration as that of the liquid container  50 . In an application using this electrical connector  50   a , ink is supplied from a tank (liquid reservoir)  902  that is placed outside to contain ink, to the printer  10  via a liquid flow tube (hose)  900  arranged to connect the tank  902  with the liquid introduction portion  362 . The liquid supply tube (hose)  900  may be connected halfway in the liquid flow tube from the liquid introduction portion  362  to the liquid ejection assembly of the printer  10 . The configuration of  FIG. 47  provides the similar advantageous effects to those of the above embodiment. For example, the contact plane TP is inclined such that the lower side is located on the first direction side (−K1-axis direction side) of the upper side as shown in  FIG. 17D . The surface  62   fa  of the terminal holder  62  is accordingly inclined such that the upper side is protruded more than the lower side in the opposite direction (+K1-axis direction) to the first direction as shown in  FIG. 24 . In other words, the surface  62   fa  of the terminal holder  62  is arranged to cover over the contacts cp of the circuit board  582 . This configuration reduces the possibility that impurity such as dust adheres to the electrical connection structure  382  (for example, the surface  62   fa  or the apparatus-side terminals  381 ). This accordingly ensures more favorable electrical connection between the container-side electrical connection structure  582  and the apparatus-side electrical connection structure  382 . 
     B-6. Sixth Modification 
     In the above embodiment, the container-side electrical connection structure includes the circuit board  582 . This configuration is, however, not restrictive, but the container-side electrical connection structure may have any configuration that includes the contacts cp configured to come into contact with the apparatus-side electrical connection structure  382 . For example, the circuit board  582  may not be provided with the storage device  583 . For example, the container-side electrical connection structure  582  may include a contact of a terminal used for detection of mounting or demounting of the liquid container  50 . The container-side electrical connection structure  582  may include an overall circuit board including a flexible cable, such as flexible printed circuit board (FPC). A contact configured to come into contact with the apparatus-side electrical connection structure  382  is provided on one end of this circuit board, and the other end may be connected with, for example, are reset device. This modified configuration may be employed in place of the circuit board  582  or may be employed in addition to the circuit board  582 . 
     The disclosure is not limited to any of the embodiments, the examples and the modifications described above but may be implemented by a diversity of other configurations without departing from the scope of the disclosure. For example, the technical features of any of the embodiments, the examples and the modifications corresponding to the technical features of each of the aspects described in Summary may be replaced or combined appropriately, in order to solve part or all of the problems described above or in order to achieve part or all of the advantageous effects described above. Any of the technical features may be omitted appropriately unless the technical feature is described as essential herein. 
     REFERENCE SIGNS LIST 
       10  printer (liquid consuming apparatus),  11  recording mechanism,  16  paper feed tray,  17  paper eject tray,  20  liquid supply device,  20 A first liquid supply device,  20 B second liquid supply device,  22 ,  22 A,  22 B cover member (liquid container holder),  26 ,  26 A,  26 B housing space,  27  bottom face,  30 ,  30 C,  30 M,  30 Y,  30 K mounting/demounting unit,  32  first stationary member,  33  second stationary member,  35  stationary member,  36  liquid introduction mechanism,  37  fixation structure,  37 A first partition wall,  37 B second partition wall,  37 S receiving space,  38  electrical connection unit (contact mechanism),  39 ,  39 A,  39 B coil spring,  40  first support assembly (movable member),  41  base portion,  41   u  bottom,  42  supply portion support structure,  46  first side face,  47  second side face,  48  board support structure,  49  bottom (bottom wall),  50 ,  50 C,  50 M,  50 Y,  50 K liquid container (liquid container unit),  51  container body support assembly,  51 W peripheral area,  51 Y peripheral area,  52 ,  52 C,  52 K liquid container body,  53  operation member,  54  grip portion,  55  liquid supply unit,  56  container body-side support structure,  57  liquid lead-out portion (liquid supply portion, flow portion),  58  substrate unit,  59  holding structure (circuit board holding structure),  62  terminal holder,  62   b  lower end,  62   u  upper end,  62   fa  surface,  70  flow path member,  99  film,  101  top face,  102  apparatus first surface (front face),  104  apparatus second surface,  106  apparatus third surface,  107  rear face,  301  screw,  302 , screw,  302 H through hole,  307 A first mounting wall,  307 B second mounting wall,  320  liquid flow tube,  323  sheet metal,  325  coil spring,  354  cover portion (protective member),  357  bottom,  362  liquid supply connection structure (liquid introduction portion),  362 H liquid introducing hole,  362   a  leading edge,  362   b  base end,  364  supply portion positioning structure,  364   a  first supply portion positioning structure,  364   b  second supply portion positioning structure,  364   c  third supply portion positioning structure,  364   d  fourth supply portion positioning structure,  365  guide structure,  366  second support structure (fixation structure),  366 B wall portion,  366 H inner housing space,  367  coil spring,  368  liquid introduction main body,  369  liquid flow portion,  371  second mounting portion,  372  second mounting portion,  374  connecting flow path portion  374 A flow path forming portion,  374 B connection structure,  374   e  connection structure base end,  374   r  recess,  376  restriction element,  376 A first restriction element,  376 B second restriction element,  376 C third restriction element,  377  first mounting portion,  377 M,  377   a ,  377   b  apparatus-side upper restriction portion,  378  first mounting portion,  381  ( 381 A- 381 I) apparatus-side terminal,  382  electrical connection structure (supply-side electrical connection structure, apparatus-side electrical connection structure),  384  apparatus-side board positioning structure (first contact-side positioning structure),  384   a  first restriction element,  384   b  second restriction element,  384   c  third restriction element,  384   d  fourth restriction element,  384   e  locking element,  385  second contact-side positioning structure,  385   a  first restriction element,  385   b  second restriction element,  385   c  third restriction element,  385   d  fourth restriction element,  385   e  locking element,  387  coil spring,  387 A one end,  387 B other end,  388  holding member,  392  support wall portion,  392   ta  top face,  393  rib,  393   ta  top face,  394  first side wall,  395  support wall portion,  396  second side wall,  402  first support surface,  403  second support surface,  404  third support surface,  406  cutout portion,  407  groove,  462  locking pawl,  465  guiding portion,  465 A first guiding portion,  465 B second guiding portion,  472  locking pawl,  482  first board support surface,  487  bottom support surface (apparatus-side rotation restriction element),  489  apparatus-side restriction element,  501  one end,  521  first sheet,  522  second sheet,  523  third sheet,  541  grip surface,  542  receiving space,  545  pressed portion,  546  first connecting portion,  547  second connecting portion,  548  base portion,  549  mounting portion,  550  lead-out portion,  551  valve mechanism,  552  valve seat,  554  valve element,  556  spring,  558  inner flow path,  569  bottom,  572  liquid supply port,  573  supply connecting portion,  577  positioning structure,  577   a  first container-side positioning structure,  577   b  second container-side positioning structure,  577   c  third container-side positioning structure,  577   d  fourth container-side positioning structure,  580  liquid container-side terminal group,  581  ( 581 A- 581 I) liquid container-side terminal,  582  electrical connection structure (circuit board, container-side electrical connection structure),  582   fa  surface,  582   fb  rear face,  583  storage device,  584  boss groove,  585  boss hole,  586  upper end,  587  lower end,  592  first side wall portion,  592   t  holding structure-side positioning element (groove),  592   ta  top face,  592   tb  side face,  592   tc  base end face,  592   td  bottom face,  593  second side wall portion,  593   t  holding structure-side positioning element (groove),  593   ta  top face,  593   tb  side face,  593   tc  base end face,  593   td  bottom face,  594  placement portion,  595  bottom (rotation restriction element),  597  restriction element,  599   a  holding structure-side upper restriction portion,  599   b  holding structure-side upper restriction portion,  602  connector,  1000  liquid consumption system, CL center axis, TP contact plane, CT center axis, cp contact.