Patent Publication Number: US-2023158799-A1

Title: Storage device and liquid ejection apparatus

Description:
The present application is based on, and claims priority from JP Application Serial Number 2021-190869, filed Nov. 25, 2021, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a storage device and a liquid ejection apparatus. 
     2. Related Art 
     A technique for detecting a storage amount of an object stored in a storage device has been proposed. For example, JP-A-2008-230227 describes a remaining amount detection sensor that detects a remaining amount of contents of a container. This type of remaining amount detection sensor includes a detection electrode arranged to face the container and a guard electrode arranged to face the detection electrode. The remaining amount detection sensor detects the remaining amount of the contents of the container based on a capacitance measured by the detection electrode with a potential of the guard electrode as a reference potential. 
     By the way, depending on a use of a device for detecting a storage amount of an object stored in a storage device, it is required to improve a detection accuracy of the storage amount of the object stored in the storage device. In the storage device of the related art, there is a room for further improvement from a viewpoint of improving the detection accuracy of the storage amount of the object. 
     SUMMARY 
     In order to solve the above problems, a storage device according to an aspect of the present disclosure includes a storage section including a plurality of walls and storing an object in a space surrounded by the plurality of walls; and a flexible printed substrate fixed to the storage section, in which the storage section includes a first positioning portion, and the flexible printed substrate includes a first electrode provided in a first wall among the plurality of walls, a second electrode provided in a second wall among the plurality of walls, a first wiring coupled to the first electrode, a second wiring coupled to the second electrode, and a second positioning portion that is coupled to the first positioning portion to determine a position of the flexible printed substrate. 
     Further, a liquid ejection apparatus according to another aspect of the present disclosure includes a storage device storing a liquid; a detection circuit detecting a storage amount of the liquid stored in the storage device; and an ejection section ejecting the liquid supplied from the storage device, in which the storage device includes a storage section including a plurality of walls and storing the liquid in a space surrounded by the plurality of walls, and a flexible printed substrate fixed to the storage section, the storage section includes a first positioning portion, and the flexible printed substrate includes a first electrode provided in a first wall among the plurality of walls, a second electrode provided in a second wall among the plurality of walls, a first wiring coupled to the first electrode, a second wiring coupled to the second electrode, and a second positioning portion that is coupled to the first positioning portion to determine a position of the flexible printed substrate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an explanatory diagram for explaining an example of a configuration of a liquid ejection apparatus according to an embodiment of the present disclosure. 
         FIG.  2    is a perspective view showing an example of an ink tank. 
         FIG.  3    is a schematic view of the ink tank seen from a +Y direction. 
         FIG.  4    is a perspective view showing an example of a schematic internal structure of the ink tank. 
         FIG.  5    is a schematic view of the ink tank seen from a −Z direction. 
         FIG.  6    is a schematic view of the ink tank seen from a −X direction and the ink tank seen from a +Z direction. 
         FIG.  7    is a cross-sectional view showing an example of a cross section of the ink tank and a flexible printed substrate taken along the line A 1 -A 2  shown in  FIG.  3   . 
         FIG.  8    is an explanatory diagram for explaining the outline of a method for detecting a storage amount of ink in the ink tank. 
         FIG.  9    is an explanatory diagram for explaining a relationship between a liquid level of the ink in the ink tank and a detection signal. 
         FIG.  10    is a circuit diagram of a detection circuit. 
         FIG.  11    is a plan view showing an example of the flexible printed substrate. 
         FIG.  12    is an explanatory diagram for explaining an example of a relationship between a capacitance between an input electrode and a detection electrode and a size of the detection electrode. 
         FIG.  13    is an explanatory diagram for explaining another example of the relationship between the capacitance between the input electrode and the detection electrode and the size of the detection electrode. 
         FIG.  14    is a flowchart showing an example of an operation of a control unit. 
         FIG.  15    is an explanatory diagram for explaining an example of a method for manufacturing a tank unit. 
         FIG.  16    is an explanatory diagram for explaining an example of detecting the storage amount of the ink when the ink tank is inclined. 
         FIG.  17    is an explanatory diagram for explaining the outline of an ink tank according to a first comparative example. 
         FIG.  18    is a plan view showing an example of a flexible printed substrate according to a first modification example. 
         FIG.  19    is an explanatory diagram for explaining the outline of a flexible printed substrate according to a second modification example. 
         FIG.  20    is a plan view showing an example of the flexible printed substrate shown in  FIG.  19   . 
         FIG.  21    is a cross-sectional view showing an example of a cross section of an ink tank and a flexible printed substrate according to a third modification example. 
         FIG.  22    is a cross-sectional view showing an example of a cross section of an ink tank and a flexible printed substrate according to a fourth modification example. 
         FIG.  23    is a plan view showing an example of the ink tank shown in  FIG.  22   . 
         FIG.  24    is an explanatory diagram for explaining the outline of an ink tank and a flexible printed substrate according to a fifth modification example. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, embodiments for carrying out the present disclosure will be explained with reference to the drawings. However, in each figure, the dimensions and scale of each portion are different from the actual dimension and scale as appropriate. Further, since embodiments described below are preferred specific examples of the present disclosure, various technically preferable limitations are attached, but the scope of the present disclosure is not limited to the limited forms unless stated otherwise to particularly limit the present disclosure in the following description. 
     1. Embodiment 
     First, a configuration of an ink jet printer  1  according to the present embodiment will be explained with reference to  FIG.  1   . 
       FIG.  1    is an explanatory diagram for explaining an example of the configuration of the ink jet printer  1  according to the embodiment of the present disclosure. Note that  FIG.  1    shows an example of a partial configuration of the ink jet printer  1 . The ink jet printer  1  is an example of a “liquid ejection apparatus”. 
     For example, the ink jet printer  1  ejects ink INK to form an image on a print medium P such as printing paper. Specifically, the ink jet printer  1  is supplied with print data indicating an image to be formed by the ink jet printer  1  from a host computer such as a personal computer or a digital camera. The ink jet printer  1  executes a printing process of forming an image indicated by the print data supplied from the host computer on the print medium P. The print medium P is not limited to the printing paper. For example, the print medium P may be a medium of any material such as a resin film or a cloth. In addition, the ink INK is an example of an “object” and a “liquid”. In the present embodiment, it is assumed that the ink jet printer  1  is a serial printer. The ink jet printer  1  may have any of a copy function, a scanner function, a facsimile transmission function, and a facsimile reception function in addition to a printing function. That is, the ink jet printer  1  may correspond to a so-called “multifunction device”. 
     The ink jet printer  1  includes, for example, a management unit  2 , a control unit  4 , an ejection unit  6 , and the like. The management unit  2  includes, for example, a tank unit  10  for storing the ink INK and a detection circuit  20  for detecting a storage amount of the ink INK stored in the tank unit  10 . For example, the management unit  2  is a storage amount management device that manages the storage amount of the ink INK stored in the tank unit  10 . 
     The tank unit  10  includes, for example, a plurality of ink tanks  100  having a one-to-one correspondence with a plurality of different types of the ink INK, and a plurality of flexible printed substrates  200  having a one-to-one correspondence with the plurality of ink tanks  100 . The tank unit  10  is an example of a “storage device”, and the ink tank  100  is an example of a “storage section”. 
     In the present embodiment, it is assumed that the types of the ink INK are a total of five types including cyan, magenta, yellow, and two types of black. In this case, the tank unit  10  includes five ink tanks  100  having a one-to-one correspondence with five types of the ink INK. The types of the ink INK are not limited to five types. That is, the number of the ink tanks  100  included in the tank unit  10  is not limited to five. For example, when there is only one type of the ink INK, the tank unit  10  may include one ink tank  100 . 
     Each ink tank  100  stores the corresponding ink INK among a plurality of types of the ink INK. Each flexible printed substrate  200  is fixed to the corresponding ink tank  100  among a plurality of the ink tanks  100 . Hereinafter, the flexible printed substrates are also referred to as flexible printed circuits (FPC). The details of the ink tank  100  and the FPC  200  will be described later in  FIG.  2    and the like. The details of the detection circuit  20  will be described later in  FIG.  10   . 
     The control unit  4  is, for example, a processor that controls each portion of the ink jet printer  1 . For example, the control unit  4  includes one or a plurality of central processing units (CPU) (not shown). The control unit  4  functions, for example, as a control section that controls the management unit  2 , the ejection unit  6 , and the like by operating according to a control program. All or a part of elements realized by the control unit  4  executing the control program are realized by hardware by an electronic circuit such as a field programmable gate array (FPGA) or an application specific IC (ASIC). Alternatively, all or a part of the respective functions of the control unit  4  may be realized by cooperation of software and hardware. The control program may be stored in a storage device (not shown) included in the control unit  4 , or may be transmitted from another device via a network. 
     The ejection unit  6  includes, for example, a plurality of head units  30  having a one-to-one correspondence with a plurality of the ink tanks  100 , a carriage  32 , a timing belt  40 , a carriage guide shaft  42 , a carriage transport mechanism  43 , a transport roller  44 , and a medium transport mechanism  45 , a platen  46 , and the like. Each head unit  30  includes a plurality of ejection sections  30   a  for ejecting the ink INK supplied from the tank unit  10  via a tube  14 . For example, the ejection unit  6  ejects the ink INK from the ejection section  30   a  while transporting the print medium P in a sub-scanning direction SD 2  and reciprocating a plurality of the head units  30  along a main scanning direction SD 1  intersecting the sub-scanning direction SD 2  under control of the control unit  4 . As a result, dots corresponding to the print data are formed on the print medium P. 
     The plurality of head units  30  are mounted on the carriage  32 . For example, when the printing process is executed, the ejection unit  6  reciprocates the carriage  32  along the main scanning direction SD 1  and transports the print medium P in the sub-scanning direction SD 2  so that a position of the print medium P relative to each head unit  30  is changed. As a result, the ejection unit  6  enables the ink INK to land on the entire print medium P. 
     The carriage guide shaft  42  reciprocally supports the carriage  32  along the main scanning direction SD 1 . The timing belt  40  is fixed to the carriage  32  and driven by the carriage transport mechanism  43 . As a result, the ejection unit  6  can reciprocate the plurality of head units  30  together with the carriage  32  along the carriage guide shaft  42 . The transport roller  44  rotates in response to the drive of the medium transport mechanism  45 , and transports the print medium P on the platen  46  in the sub-scanning direction SD 2 . The print medium P is located between the platen  46  and the carriage  32 . 
     The configuration of the ink jet printer  1  is not limited to the example shown in  FIG.  1   . For example, in  FIG.  1   , a case where the tank unit  10  is provided outside the carriage  32  is illustrated, but the tank unit  10  may be stored in the carriage  32  as an ink cartridge. Further, for example, the ink jet printer  1  may be a line printer. 
       FIG.  2    is a perspective view showing an example of the ink tank  100 . In the below, the configuration and the like of the tank unit  10  will be explained mainly regarding one ink tank  100  among the plurality of ink tanks  100  included in the tank unit  10  and the FPC  200  fixed to the ink tank  100 . For example,  FIG.  2    shows one ink tank  100  among the plurality of ink tanks  100  included in the tank unit  10  and the FPC  200  fixed to the ink tank  100 . 
     In the below, for convenience of explanation, a three-axis Cartesian coordinate system having an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other will be appropriately introduced. Further, in the below, a direction pointed by an arrow on the X-axis is referred to as a +X direction, and a direction opposite to the +X direction is referred to as a −X direction. A direction pointed by an arrow on the Y-axis is referred to as a +Y direction, and a direction opposite to the +Y direction is referred to as a −Y direction. A direction pointed by an arrow on the Z-axis is referred to as a +Z direction, and a direction opposite to the +Z direction is referred to as a −Z direction. Further, in the below, the +X direction and the −X direction may be referred to as an X direction without particular distinction, and the +Y direction and the −Y direction may be referred to as a Y direction without particular distinction. Further, the +Z direction and the −Z direction may be referred to as a Z direction without particular distinction. Further, in the below, the +Z direction may be referred to as an upper side, and the −Z direction may be referred to as a lower side. In the present embodiment, it is assumed that the −Z direction is a gravity direction. For example, the −Z direction corresponds to a direction in which the ink INK decreases. Further, in the below, viewing an object from a specific direction may be referred to as a plan view. 
     The ink tank  100  includes, for example, a plurality of outer walls  120 , a discharge section  150  for discharging the ink INK from the ink tank  100 , a supply port  160  for supplying the ink INK to the ink tank  100 , a coupling portion  170 , an adjustment port  180 , and an attachment portion  190 . The tube  14  is coupled to the coupling portion  170 . The adjustment port  180  is an introduction port for introducing air for adjusting a pressure inside the ink tank  100 . The attachment portion  190  is a mechanism for attaching the ink tank  100  to the ink jet printer  1 . 
     The plurality of outer walls  120  include, for example, outer walls  120   a ,  120   b ,  120   c ,  120   d  and  120   e . In  FIG.  2   , in order to make the figure easier to see, reference numerals of some outer walls  120  among the plurality of outer walls  120  are omitted. 
     A material of the plurality of outer walls  120  is not particularly limited as long as the material is a dielectric and does not allow the ink INK to pass therethrough. For example, the material of the plurality of outer walls  120  may be various resin materials such as polyolefin, polycarbonate and polyester, or various glass materials. Further, the material of the plurality of outer walls  120  may be a hard material or a soft material. Alternatively, a part of the plurality of outer walls  120  may be formed of a hard material and the other part may be formed of a soft material. 
     For example, among the plurality of outer walls  120 , the outer wall  120   a  may be formed of a soft material such as a film, and the outer wall  120  other than the outer wall  120   a  may be formed of a hard material such as a plastic. An elastic modulus of the hard material is, for example, greater than an elastic modulus of the soft material. In the present embodiment, it is assumed that the outer wall  120   a  of the plurality of outer walls  120  is formed of a nylon film, and the outer wall  120  other than the outer wall  120   a  of the plurality of outer walls  120  is formed of a plastic having a higher elastic modulus than the nylon film. In this case, for example, the outer wall  120   a  thinner than the outer wall  120   b  can be easily formed. In the present embodiment, since an elastic modulus of the outer wall  120   b  is larger than an elastic modulus of the outer wall  120   a , for example, it is possible to suppress deformation of the outer wall  120   b  due to a pressure inside the ink tank  100  or the like as compared with a case where the elastic modulus of the outer wall  120   b  is the same as the elastic modulus of the outer wall  120   a.    
     In the present embodiment, among the plurality of outer walls  120 , all the outer walls  120  other than the outer wall  120   a  are formed of a plastic, so that the ink tank  100  which is hard to be deformed can be easily manufactured. For example, in the present embodiment, the ink tank  100  can be easily manufactured by adhering the outer wall  120   a  formed of a nylon film to the outer wall  120  formed of a plastic. 
     As shown in  FIG.  2   , the outer walls  120   a  and  120   b  are arranged apart from each other in the Y direction, and form a side wall substantially parallel to an X-Z plane among the side walls of the ink tank  100 . In addition, “substantially parallel”, and “substantially orthogonal” and “substantially perpendicular”, which will be described later, are concepts including errors. For example, “substantially parallel” may be parallel in design. Further, the outer walls  120   c  and  120   d  are arranged apart from each other in the X direction, and form a side wall substantially parallel to a Y-Z plane among the side walls of the ink tank  100 . For example, the outer wall  120   c  is arranged between the outer walls  120   a  and  120   b , and is coupled to a part of the outer wall  120   a  and a part of the outer wall  120   b  at edge portions of the outer walls  120   a  and  120   b  in the +X direction. For example, the outer wall  120   d  is arranged between the outer walls  120   a  and  120   b , and is coupled to a part of the outer wall  120   a  and a part of the outer wall  120   b  at edge portions of the outer walls  120   a  and  120   b  in the −X direction. 
     The outer wall  120   e  includes a plane substantially parallel to an X-Y plane and constitutes a bottom portion of the ink tank  100 . For example, the outer wall  120   e  is arranged between the outer walls  120   a  and  120   b  and is coupled to a part of the outer wall  120   a  and a part of the outer wall  120   b  at edge portions of the outer walls  120   a  and  120   b  in the −Z direction. The outer walls  120   a ,  120   b ,  120   c ,  120   d  and  120   e  constitute a box that is open in the +Z direction. An opening of the box is closed by, for example, the outer wall  120  other than the outer walls  120   a ,  120   b ,  120   c ,  120   d  and  120   e  among the plurality of outer walls  120 . 
     The outer walls  120   a  and  120   b  may be provided to be inclined at a predetermined angle with respect to the X-Z plane. Similarly, the outer walls  120   c  and  120   d  may be provided to be inclined at a predetermined angle with respect to the Y-Z plane. 
     The outer wall  120   a  includes, for example, a first arrangement portion PP 1  provided with an input electrode  210  into which an AC signal for detecting the storage amount of the ink INK stored in the ink tank  100  is input. For example, a portion of the outer wall  120   a  including a target arrangement portion in which the input electrode  210  is to be provided and a peripheral portion of the target arrangement portion corresponds to the first arrangement portion PP 1 . The first arrangement portion PP 1  includes, for example, the peripheral portion of the target arrangement portion of the input electrode  210  so as to include the entire input electrode  210  in a plan view from the −Y direction even when an attachment position of the FPC  200  with respect to the outer wall  120   a  deviates from a predetermined position due to an attachment error or the like. 
     For example, a width WP 1   x  of the first arrangement portion PP 1  in the X direction is larger than a width W 10   x  of the input electrode  210  in the X direction, and a width WP 1   z  of the first arrangement portion PP 1  in the Z direction is larger than a width W 10   z  of the input electrode  210  in the Z direction. 
     A part of the FPC  200  is attached to an outer surface OF 1  of the outer wall  120   a . In the present embodiment, in the outer surface OF 1  of the outer wall  120   a , a lowercase alphabet “a” is added to an end of a code of the outer surface OF 1  of the first arrangement portion PP 1 . 
     The FPC  200  includes, for example, an input electrode  210  provided in the outer surface OF 1   a  of the first arrangement portion PP 1 , a wiring  212  coupled to the input electrode  210  and extending in the X direction, and two shield wirings  240  held at a constant voltage such as a ground voltage. In  FIG.  2   , in order to distinguish the two shield wirings  240  from each other, a lowercase alphabet “a” or “b” is added to an end of a code of each of the two shield wirings  240 . For example, a shield wiring  240   a  is the shield wiring  240  provided in the −Z direction with respect to the input electrode  210 , and a shield wiring  240   b  is the shield wiring  240  provided in the +Z direction with respect to the input electrode  210 . Also in the shield wiring  240  shown in  FIG.  3    and subsequent figures, a lowercase alphabet is added to the end of the code of the shield wiring  240  in order to distinguish it from the other shield wiring  240 . 
     The input electrode  210 , the wiring  212 , and the shield wirings  240   a  and  240   b  are examples of elements provided in the outer surface OF 1  of the outer wall  120   a  among a plurality of elements of the FPC  200 . As shown in  FIGS.  3 ,  6 ,  7   , and the like, the FPC  200  also includes elements other than the input electrode  210 , the wiring  212 , and the shield wirings  240   a  and  240   b.    
     The input electrode  210 , the wiring  212 , and the shield wirings  240   a  and  240   b  are formed of a conductive material. The conductive material may be, for example, a metal material such as gold, silver, copper, aluminum, iron, nickel and cobalt, or an alloy containing one or more kinds of metal materials. In the present embodiment, it is assumed that the input electrode  210  and the wiring  212  are integrally formed. In this case, the wiring  212  is directly coupled to the input electrode  210 . 
     The input electrode  210  is formed such that, for example, the width W 10   z  of the input electrode  210  in the Z direction is smaller than the width W 10   x  of the input electrode  210  in the X direction. For example, the input electrode  210  may be formed in a rectangular shape in which the X direction is a longitudinal direction. A shape of the input electrode  210  is not limited to the rectangular shape. In the present embodiment, the input electrode  210  is located between the shield wiring  240   a  extending in the X direction and the shield wiring  240   b  extending in the X direction. The input electrode  210  includes a portion that overlaps a center CXa of the outer wall  120   a  in the X direction in a plan view from the −Y direction. 
     In the present embodiment, in addition to the input electrode  210 , a part of the shield wiring  240   a  and a part of the shield wiring  240   b  are also provided in the outer surface OF 1   a  of the first arrangement portion PP 1 . Therefore, for example, the width WP 1   z  of the first arrangement portion PP 1  is larger than a width W 40   ab  of a portion of the FPC  200  in the Z direction including the input electrode  210  and the shield wirings  240   a  and  240   b.    
     Next, with reference to  FIG.  3   , an element facing the outer wall  120   b  among the plurality of elements of the FPC  200  will be explained. 
       FIG.  3    is a schematic view of the ink tank  100  seen from the +Y direction. In  FIG.  3   , an element provided in an outer surface OF 2  of the outer wall  120   b , which is grasped when the ink tank  100  is seen from the +Y direction, among the plurality of elements of the FPC  200 , will be mainly explained. 
     The outer wall  120   b  includes, for example, a second arrangement portion PP 2  provided with two detection electrodes  220  for detecting the storage amount of the ink INK stored in the ink tank  100 . In  FIG.  3   , in order to distinguish the two detection electrodes  220  from each other, a lowercase alphabet “a” or “b” is added to an end of a code of each of the two detection electrodes  220 . For example, the detection electrode  220   a  is a detection electrode  220  provided in the −Z direction with respect to the detection electrode  220   b.    
     In the present embodiment, it is assumed that the detection electrodes  220   a  and  220   b  have the same size. In the present embodiment, it is assumed that the two detection electrodes  220   a  and  220   b  are provided in the second arrangement portion PP 2  of the outer wall  120   b , but the number of the detection electrodes  220  provided in the second arrangement portion PP 2  is not limited to two. For example, the number of the detection electrodes  220  provided in the second arrangement portion PP 2  may be one or three or more. 
     The second arrangement portion PP 2  corresponds to, for example, a portion of the outer wall  120   b  including a target arrangement portion in which the detection electrode  220   a  and the detection electrode  220   b  are to be provided and a peripheral portion of the target arrangement portion. The second arrangement portion PP 2  includes, for example, the peripheral portion of the target arrangement portion of the detection electrode  220  so as to include the entire detection electrode  220  in a plan view from the +Y direction even when an attachment position of the FPC  200  with respect to the outer wall  120   b  deviates from a predetermined position due to an attachment error or the like. The entire detection electrode  220  includes the entire detection electrode  220   a  and the entire detection electrode  220   b.    
     For example, a width WP 2   x  of the second arrangement portion PP 2  in the X direction is larger than both a width W 20   ax  of the detection electrode  220   a  in the X direction and a width W 20   bx  of the detection electrode  220   b  in the X direction. A width WP 1   z  of the second arrangement portion PP 2  in the Z direction is larger than a width W 20   ab  of a portion of the FPC  200  in the Z direction including the detection electrodes  220   a  and  220   b.    
     A part of the FPC  200  is attached to the outer surface OF 2  of the outer wall  120   b . In the present embodiment, in the outer surface OF 2  of the outer wall  120   b , a lowercase alphabet “a” is added to an end of a code of the outer surface OF 2  of the second arrangement portion PP 2 . 
     The FPC  200  includes, for example, the detection electrodes  220   a  and  220   b  provided in the outer surface OF 2   a  of the second arrangement portion PP 2 , a wiring  222   a  coupled to the detection electrode  220   a  and extending in the X direction, and a wiring  222   b  coupled to the detection electrode  220   b  and extending in the X direction. Further, the FPC  200  includes a shield wiring  240   c  held at a constant voltage such as a ground voltage. The shield wiring  240   c  is a shield wiring  240  located between the detection electrode  220   a  and the detection electrode  220   b . Therefore, a part of the shield wiring  240   c  is provided in the outer surface OF 2   a  of the second arrangement portion PP 2 . In the present embodiment, a part of the shield wiring  240   a  and a part of the shield wiring  240   b  are also provided in the outer surface OF 2   a  of the second arrangement portion PP 2 . 
     For example, the detection electrode  220   a  is located between the shield wiring  240   a  extending in the X direction and the shield wiring  240   c  extending in the X direction, and the detection electrode  220   b  is located between the shield wiring  240   b  extending in the X direction and the shield wiring  240   c  extending in the X direction. The shield wiring  240   c  is located between the shield wiring  240   a  and the shield wiring  240   b.    
     The detection electrode  220   a  includes a portion that overlaps a center CXb of the outer wall  120   b  in the X direction in a plan view from the +Y direction. Similarly, the detection electrode  220   b  includes a portion that overlaps the center CXb of the outer wall  120   b  in the X direction in a plan view from the +Y direction. In the present embodiment, the center CXb of the outer wall  120   b  in the X direction substantially coincides with the center CXa of the outer wall  120   a  in the X direction. A position of the supply port  160  in the X direction and a position of the detection electrode  220   a  in the X direction are different from each other. Similarly, the position of the supply port  160  in the X direction and a position of the detection electrode  220   b  in the X direction are different from each other. 
     As described above, in the present embodiment, the detection electrodes  220   a  and  220   b , a part of the shield wiring  240   a , a part of the shield wiring  240   b , and a part of the shield wiring  240   c  are provided in the outer surface OF 2   a  of the second arrangement portion PP 2 . Therefore, for example, a width WP 2   z  of the second arrangement portion PP 2  is larger than a width W 40   cd  of a portion of the FPC  200  in the Z direction including the detection electrodes  220   a  and  220   b  and the shield wirings  240   a ,  240   b  and  240   c.    
     The overall outline of the FPC  200  will be described later in  FIG.  11   . For example, the detection electrode  220   a  is formed such that a width W 20   az  of the detection electrode  220   a  in the Z direction is smaller than the width W 20   ax  of the detection electrode  220   a  in the X direction. Similarly, the detection electrode  220   b  is formed such that a width W 20   bz  of the detection electrode  220   b  in the Z direction is smaller than the width W 20   bx  of the detection electrode  220   b  in the X direction. In the present embodiment, the detection electrodes  220   a  and  220   b  are grasped as a rectangular shape in which the X direction is a longitudinal direction in a plan view from the +Y direction. The shapes of the detection electrodes  220   a  and  220   b  are not limited to the rectangular shape. 
     Further, the detection electrodes  220   a  and  220   b , the wiring  222   a  and  222   b , and the shield wiring  240   c  are formed of the same material as that of the input electrode  210 . In the present embodiment, it is assumed that the detection electrode  220   a  and the wiring  222   a  are integrally formed, and the detection electrode  220   b  and the wiring  222   b  are integrally formed. In this case, the wiring  222   a  is directly coupled to the detection electrode  220   a , and the wiring  222   b  is directly coupled to the detection electrode  220   b.    
     Next, an internal structure of the ink tank  100  will be explained with reference to  FIG.  4   . 
       FIG.  4    is a perspective view showing an example of a schematic internal structure of the ink tank  100 . 
     For example, a plurality of partition walls  122 , a plurality of support portions  130 , and a plurality of auxiliary portions  140  are provided inside the ink tank  100 . In  FIG.  4   , in order to distinguish the plurality of support portions  130  from each other, a lowercase alphabet “a”, “b” or “c” is added to an end of a code of each of the plurality of support portions  130 . Similarly, a lowercase alphabet “a”, “b”, “c”, “d” or “e” is added to an end of a code of each of the plurality of auxiliary portions  140 . The number of the support portions  130  and the number of the auxiliary portions  140  are not limited to the example shown in  FIG.  4   . For example, the number of the support portions  130  may be one or two. Alternatively, the number of the support portions  130  may be four or more. The plurality of partition walls  122  include, for example, partition walls  122   a  and  122   b.    
     For example, a partition wall  122   a  is arranged apart from the outer wall  120   d  in the −X direction so as to face the outer wall  120   d . The partition wall  122   a  is located closer to the outer wall  120   d  than the outer wall  120   a . For example, air for adjusting the pressure inside the ink tank  100  is introduced into a space between the outer wall  120   d  and the partition wall  122   a  through the adjustment port  180 . For example, the ink INK is stored in a space SP surrounded by the partition wall  122   a  and the outer walls  120   a ,  120   b ,  120   c  and  120   e.    
     The partition wall  122   b  separates, for example, a flow path (not shown) of the ink INK supplied from the supply port  160  from the space SP. For example, the partition wall  122   b  is arranged apart from the outer wall  120   e  in the +Z direction so as to face the outer wall  120   e . In the present embodiment, the partition wall  122   b  is located in the +Z direction with respect to the second arrangement portion PP 2  of the outer wall  120   b.    
     In this way, the space SP in which the ink INK is stored is partitioned by the outer walls  120   a ,  120   b ,  120   c  and  120   e  and the partition walls  122   a  and  122   b . The outer walls  120   a ,  120   b ,  120   c  and  120   e  and the partition walls  122   a  and  122   b  are examples of “a plurality of walls”. 
     The support portion  130   a  supports, for example, the outer walls  120   a  and  120   b . For example, the support portion  130   a  includes a plurality of rod portions  132  that support the outer walls  120   a  and  120   b , a plurality of plate portions  134  that support the outer walls  120   a  and  120   b , and an auxiliary support portion  136 . In  FIG.  4   , in order to distinguish the plurality of rod portions  132  from each other, a lowercase alphabet “a”, “b” or “c” is added to an end of a code of each of the plurality of rod portions  132 . Similarly, a lowercase alphabet “a”, “b” or “b” is added to an end of a code of each of the plurality of plate portions  134 . 
     Each rod portion  132  is, for example, a columnar body extending in the Y direction. In the example shown in  FIG.  4   , each rod portion  132  is a cylinder, but each rod portion  132  may be a prism. The plurality of rod portions  132  are arranged, for example, in the Z direction. An end portion E 1  which is one end of each rod portion  132  is adhered to the outer wall  120   a , and an end portion E 2  which is the other end of each rod portion  132  is adhered to the outer wall  120   b.    
     Each plate portion  134  includes, for example, a plane substantially parallel to the Y-Z plane. That is, each plate portion  134  includes a plane substantially orthogonal to the outer wall  120   b . Two edge portions of the plate portion  134   a  along the Z direction are coupled to the outer walls  120   a  and  120   b , respectively, and two edge portions of the plate portion  134   a  along the Y direction are coupled to the rod portions  132   a  and  132   b , respectively. Further, two edge portions of the plate portion  134   b  along the Z direction are coupled to the outer walls  120   a  and  120   b , respectively, and two edge portions of the plate portion  134   b  along the Y direction are coupled to the rod portions  132   b  and  132   c , respectively. 
     The auxiliary support portion  136  is grasped, for example, as a substantially right triangular shape, in a plan view from the +Z direction. For example, among edge portions of the auxiliary support portion  136 , two edge portions corresponding to two sides other than an oblique side of a right triangle are coupled to the outer wall  120   b  and the rod portion  132   b , respectively. The rod portion  132   b  is stably fixed to the outer wall  120   b  by the auxiliary support portion  136 . 
     The configurations of the support portions  130   b  and  130   c  are the same as that of the support portion  130   a . For example, the support portions  130   b  and  130   c  also support the outer walls  120   a  and  120   b  in the same manner as the support portion  130   a . Although the reference numerals of elements such as the rod portion  132  included in the support portions  130   b  and  130   c  are omitted in  FIG.  4   , the elements included in the support portions  130   b  and  130   c  are referred to by using the same reference numerals as the elements included in the support portion  130   a.    
     In the present embodiment, it is assumed that the support portions  130   a  and  130   b  are arranged at two edge portions of the first arrangement portion PP 1  along the Z direction, respectively. For example, the support portions  130   a  and  130   b  extend along the +Y direction, which is a direction from the first arrangement portion PP 1  toward the second arrangement portion PP 2 , and support the first arrangement portion PP 1  and the second arrangement portion PP 2 . Since the illustration of the first arrangement portion PP 1  of the outer wall  120   a  is omitted in  FIG.  4   , a positional relationship between the support portions  130   a  and  130   b  and the first arrangement portion PP 1  will be described later in  FIG.  5   . 
     The plurality of auxiliary portions  140  are grasped as a substantially right triangular shape, for example, in a plan view from the +X direction. For example, among edge portions of the auxiliary portion  140   a , two edge portions corresponding to two sides other than an oblique side of a right triangle are coupled to the outer walls  120   b  and  120   e , respectively. Also in the auxiliary portions  140   b  and  140   c , similarly to the auxiliary portion  140   a , two edge portions corresponding to two sides other than an oblique side of a right triangle are coupled to the outer walls  120   b  and  120   e , respectively. The outer walls  120   b  and  120   e  are stably fixed to each other by the auxiliary portions  140   a ,  140   b  and  140   c . Further, among edge portions of the auxiliary portion  140   d , two edge portions corresponding to two sides other than an oblique side of a right triangle are coupled to the outer wall  120   c  and the partition wall  122   b , respectively. Also in the auxiliary portion  140   e , similarly to the auxiliary portion  140   d , two edge portions corresponding to two sides other than an oblique side of a right triangle are coupled to the outer wall  120   c  and the partition wall  122   b , respectively. The outer wall  120   c  and the partition wall  122   b  are stably fixed to each other by the auxiliary portions  140   d  and  140   e.    
     In the present embodiment, it is assumed that the support portion  130  and the auxiliary portion  140  are subjected to a water-repellent treatment, but a part or all of the support portion  130  and the auxiliary portion  140  need not to be subjected to the water-repellent treatment. 
     The discharge section  150  is provided with a discharge port Hd that penetrates through the discharge section  150  and the outer wall  120   e  and that discharges the ink INK from the space SP. The discharge port Hd is located, for example, near a center of the outer wall  120   e  in the X direction. A positional relationship between the discharge port Hd, and the first arrangement portion PP 1  and the second arrangement portion PP 2  will be described later in  FIG.  5   . 
     The supply port  160  is open, for example, in the +Z direction. For example, an opening Hf of the supply port  160  communicates with the space SP via a flow path (not shown). As a result, the ink INK is supplied from the supply port  160  to the space SP. 
     As explained in  FIG.  2   , the tube  14  is coupled to the coupling portion  170 . The ink INK stored in the space SP is discharged from, for example, the discharge port Hd of the discharge section  150 , and reaches the coupling portion  170  via a flow path (not shown). Then, the ink INK that has reached the coupling portion  170  is supplied to the ejection section  30   a  of the head unit  30  via the tube  14  coupled to the coupling portion  170 . 
     Next, with reference to  FIG.  5   , a positional relationship between the input electrode  210  and the detection electrode  220 , and the discharge port Hd will be explained. 
       FIG.  5    is a schematic view of the ink tank  100  seen from the −Z direction. In  FIG.  5   , the positional relationship between the input electrode  210  and the detection electrode  220  and the discharge port Hd and the like are explained. In  FIG.  5   , the shield wiring  240  and the like are omitted in order to make it easier to understand the positional relationship between the input electrode  210  and the detection electrode  220  and the discharge port Hd. In  FIG.  5   , the support portions  130   a  and  130   b  are shown by broken lines in order to explain positional relationships between the first arrangement portion PP 1  of the outer wall  120   a  and the second arrangement portion PP 2  of the outer wall  120   b , and the support portions  130   a  and  130   b.    
     In the example shown in  FIG.  5   , when the discharge port Hd is seen from the −Z direction, the entire discharge port Hd is located between the input electrode  210  and the detection electrode  220 . Thereby, in the present embodiment, the storage amount of the ink INK can be detected in the vicinity of the discharge port Hd. 
     When the discharge port Hd is seen from the −Z direction, the discharge port Hd may include a portion located between the input electrode  210  and the detection electrode  220  and a portion not located between the input electrode  210  and the detection electrode  220 . Even in this case, the storage amount of the ink INK can be detected near the discharge port Hd as compared with an aspect in which the entire discharge port Hd is not located between the input electrode  210  and the detection electrode  220  when the discharge port Hd is seen from the −Z direction. Further, when the discharge port Hd is seen from the −Z direction, at least a part of the discharge port Hd may be located between the first arrangement portion PP 1  of the outer wall  120   a  and the second arrangement portion PP 2  of the outer wall  120   b . Even in this case, the storage amount of the ink INK can be detected near the discharge port Hd as compared with an aspect in which the entire discharge port Hd is not located between the first arrangement portion PP 1  and the second arrangement portion PP 2  when the discharge port Hd is seen from the −Z direction. 
     Although the details will be described later in  FIG.  16   , in the present embodiment, by detecting the storage amount of the ink INK in the vicinity of the discharge port Hd, the storage amount of the ink INK can be detected more accurately than an aspect of a first comparative example in which the storage amount of the ink INK is detected in a place far from the discharge port Hd. 
     Further, when focusing on a position of the discharge port Hd, the discharge port Hd is formed near the center of the outer wall  120   e  in the X direction. For example, the discharge port Hd is formed such that a center CXs of the space SP of the ink tank  100  in the X direction is located inside the discharge port Hd in a plan view from the −Z direction. In the example shown in  FIG.  5   , the discharge port Hd is formed such that the center CP of the space SP of the ink tank  100  is located inside the discharge port Hd in a plan view from the −Z direction. Thereby, in the present embodiment, for example, when the ink tank  100  is used in an inclined state, an amount of the ink INK remaining in the space SP without being discharged from the discharge port Hd can be reduced. 
     Further, the width W 10   x  of the input electrode  210  in the X direction and the width W 20   ax  of the detection electrode  220   a  in the X direction are larger than a width WHx of the discharge port Hd in the X direction. Thereby, in the present embodiment, as will be described later in  FIG.  16   , even when the ink tank  100  is inclined, it is possible to accurately detect whether or not the storage amount of the ink INK in the ink tank  100  is equal to or more than a predetermined lower limit value. 
     The support portions  130   a  and  130   b  are arranged at two edge portions of the first arrangement portion PP 1  of the outer wall  120   a  along the Z direction, respectively. For example, the end portion E 1  of each rod portion  132  of the support portion  130   a  is fixed to one of the two edge portions of the first arrangement portion PP 1  along the Z direction, and the end portion E 1  of each rod portion  132  of the support portion  130   b  is fixed to the other of the two edge portions of the first arrangement portion PP 1  along the Z direction. The end portion E 2  of each rod portion  132  of the support portion  130   a  is fixed to one of the two edge portions of the second arrangement portion PP 2  along the Z direction, and the end portion E 2  of each rod portion  132  of the support portion  130   b  is fixed to the other of the two edge portions of the second arrangement portion PP 2  along the Z direction. 
     As described above, in the present embodiment, a range of the outer wall  120   a  including positions of each rod portion  132  of the support portion  130   a  and each rod portion  132  of the support portion  130   b  in the X direction can be regarded as a range of the first arrangement portion PP 1  in the X direction. Similarly, in the present embodiment, a range of the outer wall  120   b  including positions of each rod portion  132  of the support portion  130   a  and each rod portion  132  of the support portion  130   b  in the X direction can be regarded as a range of the second arrangement portion PP 2  in the X direction. 
     A thickness T 1  of the first arrangement portion PP 1  of the outer wall  120   a  is thinner than a thickness T 2  of the second arrangement portion PP 2  of the outer wall  120   b . Further, the thickness T 1  of the first arrangement portion PP 1  of the outer wall  120   a  is thinner than a thickness T 3  of the outer wall  120   d . Further, in the present embodiment, since it is assumed that the outer wall  120   a  is formed of a nylon film having a lower elastic modulus than the outer wall  120   b  or the like, the outer wall  120   a  is more easily deformed than the outer wall  120   b  or the like. Therefore, in the present embodiment, the support portions  130   a  and  130   b  for supporting the first arrangement portion PP 1  and the second arrangement portion PP 2  are provided. As a result, in the present embodiment, it is possible to suppress deformation of the first arrangement portion PP 1 . In the present embodiment, in addition to the support portions  130   a  and  130   b , the support portion  130   c  for supporting a portion of the outer wall  120   a  other than the first arrangement portion PP 1  and a portion of the outer wall  120   b  other than the second arrangement portion PP 2  is provided. Therefore, it is possible to suppress deformation of the outer wall  120   a.    
     For example, each rod portion  132  of the support portion  130   a  and each rod portion  132  of the support portion  130   b  may be arranged outside the first arrangement portion PP 1  as long as the deformation of the first arrangement portion PP 1  can be suppressed. Specifically, each rod portion  132  of the support portion  130   a  may be located in the −X direction with respect to the first arrangement portion PP 1 . Similarly, each rod portion  132  of the support portion  130   b  may be located in the +X direction with respect to the first arrangement portion PP 1 . Further, for example, the support portion  130  may be provided near a center of the first arrangement portion PP 1  in the X direction. 
     Further, for example, the plate portion  134  may be formed in a grid pattern having through holes through which the ink INK passes. Alternatively, the plate portion  134  may be omitted. The support portion  130  may include a plurality of columnar bodies extending in the Z direction instead of the plate portion  134 . In this case, the support portion  130  may be formed in a grid pattern having openings through which the ink INK passes by the plurality of columnar bodies extending in the Z direction and the plurality of rod portions  132  extending in the Y direction. Alternatively, a triangular or L-shaped support portion may be provided to support the outer walls  120   a  and  120   e . Further, for example, a plate-shaped support portion having a surface parallel to an inner surface IF 3  of the outer wall  120   e  and supporting the outer walls  120   a  and  120   b  may be provided. 
     Next, with reference to  FIG.  6   , the outline of the ink tank  100  and the like seen from the −X direction will be explained. 
       FIG.  6    is a schematic view of the ink tank  100  seen from the −X direction and the ink tank  100  seen from the +Z direction. In  FIG.  6   , a plan view shown on an upper side is a schematic view of the ink tank  100  seen from the −X direction, and a plan view shown on a lower side is a schematic view of the ink tank  100  seen from the +Z direction. In  FIG.  6   , the input electrode  210 , the detection electrode  220 , and the like are omitted in order to make the figure easier to see. 
     As shown in the schematic view of the ink tank  100  seen from the −X direction, the ink tank  100  includes, for example, positioning portions PT 10  and PT 12 . For example, the positioning portions PT 10  and PT 12  are formed of the same material as the outer wall  120   d  and are integrally formed with the outer wall  120   d . That is, in the present embodiment, the positioning portions PT 10  and PT 12  are provided in the outer wall  120   d , which is a portion formed of a material harder than that of the first arrangement portion PP 1 . The positioning portions PT 10  and PT 12  are formed, for example, in a protruding shape protruding in the −X direction from the outer wall  120   d . For example, the positioning portion PT 10  is grasped as a rectangular shape in a plan view from the −X direction. For example, the positioning portion PT 12  is grasped as a triangular shape in a plan view from the −X direction. The positioning portion PT 10  and PT 12  are provided in the outer wall  120   d , and the positioning portion PT 10  is located in the +Z direction with respect to the positioning portion PT 12 . 
     Further, the FPC  200  includes a positioning portion PT 20  that determines a position of the FPC  200  by being coupled to the positioning portion PT 10 , and a positioning portion PT 22  that determines the position of the FPC  200  by being coupled to the positioning portion PT 12 . 
     For example, as shown in the schematic view of the ink tank  100  seen from the −X direction, out of two edge portions of the FPC  200  along the Y direction, at the edge portion in the +Z direction, a cutout that is open in the +Z direction and fitted with the positioning portion PT 10  is formed as the positioning portion PT 20 . That is, a region inside the cutout formed as the positioning portion PT 20  is grasped as a rectangular shape in a plan view from the −X direction. Further, out of the two edge portions of the FPC  200  along the Y direction, at the edge portion in the −Z direction a cutout that is open in the −Z direction and fitted with the positioning portion PT 20  is formed as the positioning portion PT 22 . That is, a region inside the cutout formed as the positioning portion PT 22  is grasped as a triangular shape in a plan view from the −X direction. 
     The positioning portions PT 20  and PT 22  are not limited to the cutouts. For example, a through hole that penetrates through the FPC  200  in the X direction and is fitted with the positioning portion PT 10  may be formed as the positioning portion PT 20 . Similarly, a through hole that penetrates through the FPC  200  in the X direction and is fitted with the positioning portion PT 12  may be formed as the positioning portion PT 22 . 
     In the present embodiment, when the FPC  200  is attached to the ink tank  100 , the positioning portion PT 20  of the FPC  200  is coupled to the positioning portion PT 10  of the ink tank  100 , and the positioning portion PT 22  of the FPC  200  is coupled to the positioning portion PT 12  of the ink tank  100 . Thereby, in the present embodiment, it is possible to suppress deviation of the position of the FPC  200  with respect to the ink tank  100  from a predetermined position when the FPC  200  is attached to the ink tank  100 . 
     Further, in the present embodiment, a shape of the positioning portion PT 10  is different from a shape of the positioning portion PT 12 . Thereby, in the present embodiment, for example, it is possible to reduce that the positioning portion PT 22  is erroneously fitted with the positioning portion PT 10  or the positioning portion PT 20  is erroneously fitted with the positioning portion PT 12 . Thereby, for example, it is possible to reduce that the FPC  200  is attached to the ink tank  100  in a wrong orientation. 
     The positioning portion PT 10  and PT 12  may be formed such that one or both of a shape and a size are different between the positioning portion PT 10  and the positioning portion PT 12 . For example, when the size of the positioning portion PT 10  is different from the size of the positioning portion PT 12 , the shape of the positioning portion PT 10  and the shape of the positioning portion PT 12  may be the same as each other. Even in this case, it is possible to reduce that the FPC  200  is attached to the ink tank  100  in the wrong orientation. Hereinafter, the positioning portions PT 10 , PT 12 , PT 20  and PT 22  may be collectively referred to as positioning portions PT. 
     The FPC  200  includes a terminal TMt 1  electrically coupled to the input electrode  210 , a terminal TMr 1  electrically coupled to the detection electrode  220   a , and a terminal TMr 2  electrically coupled to the detection electrode  220   b . Further, the FPC  200  includes a plurality of terminals TMg 1  to TMg 6  held at a constant voltage such as a ground voltage. In the below, the terminals TMg 1  to TMg 6  may be collectively referred to as terminals TMg. The number of the terminals TMg is not limited to six. For example, the number of the terminals TMg may be two or more and five or less, or may be seven or more. Further, in the below, the terminals TMt 1 , TMr 1 , TMr 2  and TMg may be collectively referred to as terminals TM. The plurality of terminals TMg are formed of, for example, the same material as the input electrode  210 . 
     In the present embodiment, it is assumed that the plurality of terminals TMg are held at a ground voltage, but the plurality of terminals TMg may be held at a constant voltage other than the ground voltage. Alternatively, the plurality of terminals TMg may include the terminal TMg held at a first constant voltage such as a ground voltage and the terminal TMg held at a second constant voltage other than the first constant voltage. Each of the plurality of terminals TMg 1  to TMg 6  is electrically coupled to one or more shield wirings  240  among the plurality of shield wirings  240 . When focusing on the plurality of shield wirings  240 , each of the plurality of shield wirings  240  is electrically coupled to one or more terminals TMg among the plurality of terminals TMg 1  to TMg 6 . 
     In the present embodiment, in order to reduce an interference between two terminals TM among the terminals TMt 1 , TMr 1  and TMr 2 , one or more terminals TMg among the plurality of terminals TMg are arranged between the two terminal TM. The interference between the two terminals TM is, for example, that a signal transmitted to one of the two terminals TM is transmitted to the other terminal TM as a noise. In the present embodiment, for example, in a plan view from the −X direction, the terminal TMg that overlaps a straight line connecting any position in one terminal TM and any position in the other terminal TM of the two terminals TM corresponds to the terminal TMg located between the two terminals TM. 
     For example, among the plurality of terminals TMg, terminals TMg 1 , TMg 2 , and TMg 3  are arranged between the terminal TMt 1  and the terminal TMr 1 . Further, the terminals TMg 3  and TMg 6  are arranged between the terminal TMr 1  and the terminal TMr 2 . Further, the terminals TMg 1 , TMg 2 , TMg 4  and TMg 5  are arranged between the terminal TMr 2  and the terminal TMt 1 . 
     Further, for example, the terminal TMt 1  is in contact with a first external contact outside the FPC  200 , the terminal TMr 1  is in contact with a second external contact outside the FPC  200 , and the terminal TMr 2  is in contact with a third external contact outside the FPC  200 . For example, the first external contact is electrically coupled to an AC power supply ACP described later in  FIG.  10   . Further, for example, the second external contact is electrically coupled to an input terminal IN 1  of a selection circuit  21  described later in  FIG.  10   , and the third external contact is electrically coupled to an input terminal IN 2  of the selection circuit  21 . 
     The plurality of terminals TMg 1  to TMg 6  are in contact with, for example, a plurality of constant voltage contacts outside the FPC  200 . The plurality of constant voltage contacts are held, for example, at a constant voltage such as a ground voltage. That is, the plurality of terminals TMg 1  to TMg 6  are held at a constant voltage such as the ground voltage by being in contact with the plurality of constant voltage contacts held at a constant voltage such as the ground voltage. 
     In the present embodiment, for example, an external contact CTt 1  shown in  FIG.  8    corresponds to the first external contact, an external contact CTr 1  corresponds to the second external contact, an external contact CTr 2  corresponds to the third external contact, and external contacts CTg 1  to CTg 6  correspond to the constant voltage contacts. In the below, the external contacts CTt 1 , CTr 1 , CTr 2  and CTg 1  to CTg 6  may be collectively referred to as external contacts CT. The external contact CT is also used as a general term for the first external contact, the second external contact, the third external contact, and the plurality of constant voltage contacts. 
     The coupling between the plurality of terminals TM and the plurality of external contacts CT is realized by, for example, a spring contact. For example, the plurality of external contacts CT are provided in an external substrate that can be attached to and detached from the ink tank  100 . When the external substrate is attached to the ink tank  100 , on each of the plurality of external contacts CT provided in the external substrate, a force that pushes the external contact CT in the +X direction acts due to a repulsive force of a spring or the like. 
     Here, when focusing on a positional relationship between the plurality of terminals TM and the positioning portions PT 20  and PT 22 , in the FPC  200 , at least a part of a terminal arrangement region AR including the plurality of terminals TM is located between the positioning portion PT 20  and the positioning portion PT 22 . In a portion of the FPC  200  that is close to the positioning portions PT 20  and PT 22 , deviation of an attachment position of the FPC  200  with respect to the ink tank  100  is smaller than that in a portion of the FPC  200  that is far from the positioning portions PT 20  and PT 22 . 
     In the present embodiment, since the plurality of terminals TM are arranged near the positioning portions PT 20  and PT 22 , it is possible to reduce the deviation of the plurality of terminals TM with respect to the ink tank  100  from a predetermined position. As a result, in the present embodiment, the erroneous coupling between the plurality of terminals TM and the plurality of external contacts CT can be suppressed. Further, in the present embodiment, since it is possible to reduce the deviation of the plurality of terminals TM with respect to the ink tank  100  from the predetermined position, it is possible to improve stability of the coupling between the plurality of terminals TM and the plurality of external contacts CT. 
     Further, as shown in the schematic view of the ink tank  100  seen from the +Z direction, the FPC  200  is bent along an outer periphery of the ink tank  100  at bent portions BP 1  and BP 2 . Further, when the ink tank  100  is seen from the +Z direction, the plurality of terminals TM are provided at the edge portion EP 1  of the two edge portions EP 1  and EP 2  of the ink tank  100 , and the supply port  160  is located closer to the edge portion EP 2  than the edge portion EP 1 . The two edge portions EP 1  and EP 2  of the ink tank  100  are edge portions that are separated from each other in the X direction among edge portions that are grasped when the ink tank  100  is seen from the +Z direction. When the ink tank  100  is seen from the +Z direction, the X direction corresponds to a longitudinal direction of the ink tank  100 . In the below, an edge portion of the outer wall  120   e  in the edge portion EP 1  of the ink tank  100  may be simply referred to as the edge portion EP 1  of the outer wall  120   e . Similarly, an edge portion of the outer wall  120   e  in the edge portion EP 2  of the ink tank  100  may be simply referred to as the edge portion EP 2  of the outer wall  120   e.    
     As described above, in the present embodiment, the supply port  160  is located closer to the edge portion EP 2  than the edge portion EP 1  provided with the plurality of terminals TM. Therefore, in the present embodiment, even if the ink INK leaks from the supply port  160  when the ink INK is supplied, it is possible to prevent the leaked ink INK from contaminating the vicinity of the plurality of terminals TM. If the vicinity of the plurality of terminals TM is contaminated by ink INK or the like leaking from the supply port  160 , the plurality of terminals TM may be short-circuited. In the present embodiment, since it is possible to prevent the vicinity of the plurality of terminals TM from being contaminated by the ink INK leaking from the supply port  160 , it is possible to prevent the plurality of terminals TM from being short-circuited. 
     Next, a cross section of the ink tank  100  and the FPC  200  will be explained with reference to  FIG.  7   . 
       FIG.  7    is a cross-sectional view showing an example of a cross section of the ink tank  100  and the FPC  200  taken along the line A 1 -A 2  shown in  FIG.  3   . In  FIG.  7   , in order to make the figure easier to see, elements located in the +Z direction with respect to the partition wall  122   b , the support portion  130  and the like are not shown. 
     The FPC  200  may include, for example, a non-conductive first cover film layer  201 , a conductive first conductor layer  202 , a non-conductive base material layer  203 , a conductive second conductor layer  204 , and a non-conductive second cover film layer  205 . For example, the base material layer  203  is provided between the first cover film layer  201  and the second cover film layer  205 . Further, the first conductor layer  202  is provided between the first cover film layer  201  and the base material layer  203 , and the second conductor layer  204  is provided between the second cover film layer  205  and the base material layer  203 . 
     The first conductor layer  202  includes an input electrode  210 , detection electrodes  220   a  and  220   b , and shield wirings  240   a ,  240   b  and  240   c . Further, the first conductor layer  202  includes the wirings  212 ,  222   a  and  222   b  shown in  FIGS.  2  and  3   . Further, the second conductor layer  204  includes shield wirings  240   d  and  240   e  held at a constant voltage such as a ground voltage. Further, the second conductor layer  204  includes the terminals TMt 1 , TMr 1 , TMr 2  and TMg 1  to TMg 6  shown in  FIG.  6   . The shield wirings  240   d  and  240   e  are formed of, for example, the same material as that of the input electrode  210 . 
     The first cover film layer  201  and the second cover film layer  205  are formed of, for example, a polyimide film. The first cover film layer  201  and the second cover film layer  205  may be formed of a material other than the polyimide film. 
     Further, the tank unit  10  includes a double-sided tape  260  for adhering the FPC  200  to the ink tank  100 . For example, the first cover film layer  201  is provided between the second cover film layer  205  and the ink tank  100 , and is adhered to the ink tank  100  by the double-sided tape  260 . The double-sided tape  260  includes, for example, a base material  264 , a first adhesive layer  262  formed on a first surface SF 1  of the base material  264 , and a second adhesive layer  266  formed on a second surface SF 2  opposite to the first surface SF 1  of the base material  264 . 
     For example, the FPC  200  is adhered to a position of the ink tank  100  determined by the positioning portions PT 10 , PT 12 , PT 20  and PT 22  shown in  FIG.  6    by the double-sided tape  260 . As a result, the input electrode  210  included in the FPC  200  is provided in the outer surface OF 1   a  of the first arrangement portion PP 1  of the outer wall  120   a , and the detection electrodes  220   a  and  220   b  included in the FPC  200  are provided in the outer surface OF 2   a  of the second arrangement portion PP 2  of the outer wall  120   b . For example, the input electrode  210  is arranged at a position where the entire input electrode  210  overlaps the outer surface OF 1   a  of the first arrangement portion PP 1  in a plan view from the −Y direction. Further, the detection electrodes  220   a  and  220   b  are arranged at positions where the entire detection electrode  220   a  and the entire detection electrode  220   b  overlap the outer surface OF 2   a  of the second arrangement portion PP 2  in a plan view from the +Y direction. 
     Further, in the present embodiment, the FPC  200  is attached to the ink tank  100  such that the entire detection electrode  220   a  and the entire detection electrode  220   b  overlap the input electrode  210  in a plan view from the +Y direction. The detection electrodes  220   a  and  220   b  are arranged at different positions in the Z direction. 
     For example, in the Z direction, the detection electrode  220   a  is arranged such that a center of the detection electrode  220   a  is at a position H 1 , and the detection electrode  220   b  is arranged such that a center of the detection electrode  220   b  is at a position H 2 . The positions H 1  and H 2  are positions in the Z direction when the inner surface IF 3  of the outer wall  120   e  is a starting point, and the position H 2  is a position in the +Z direction with respect to the position H 1 . Therefore, the detection electrode  220   b  is arranged in the +Z direction with respect to the detection electrode  220   a . In the below, the position in the +Z direction with respect to a specific position is also referred to as a position higher than the specific position, and the position in the −Z direction with respect to the specific position is also referred to as a position lower than the specific position. 
     The detection electrode  220   a  may be arranged such that a side in the −Z direction of two sides of the detection electrode  220   a  along the X direction is at the position H 1 , or may be arranged such that a side in the +Z direction of the detection electrode  220   a  is at the position H 1 . Similarly, the detection electrode  220   b  may be arranged such that a side in the −Z direction of two sides of the detection electrode  220   b  along the X direction is at the position H 2 , or may be arranged such that a side in the +Z direction of the detection electrode  220   b  is at the position H 2 . 
     In the present embodiment, since the FPC  200  is provided with the shield wirings  240   d  and  240   e , it is possible to reduce the interference between the plurality of FPCs  200  having a one-to-one correspondence with the plurality of ink tanks  100  included in the tank unit  10 . The interference between the FPCs  200  is, for example, that a signal of one FPC  200  of two FPCs  200  is transmitted as a noise to one or both of the input electrode  210  and the detection electrode  220  of the other FPC  200 . 
     Further, a large amplitude signal of about 42 V is supplied to a piezoelectric element that drives the ejection section  30   a  of the head unit  30 . In the present embodiment, since the FPC  200  is provided with the shield wirings  240   d  and  240   e , it is possible to reduce transmission of the large amplitude signal supplied to the piezoelectric element to one or both of the input electrode  210  and the detection electrode  220  as a noise. 
     Further, in the present embodiment, since the FPC  200  is fixed to the ink tank  100  with the double-sided tape  260  having a substantially uniform thickness, a distance between the input electrode  210  and the outer surface OF 1   a  of the first arrangement portion PP 1  and a distance between the detection electrode  220  and the outer surface OF 2   a  of the second arrangement portion PP 2  are substantially constant. Therefore, in the present embodiment, it is possible to suppress uneven distribution of the adhesive as compared with a case where the FPC  200  is fixed to the ink tank  100  with a general curable adhesive. That is, in the present embodiment, it is possible to suppress variation of a distance between the input electrode  210  and the detection electrode  220  depending on a position in the detection electrode  220  as compared with a case where the FPC  200  is fixed to the ink tank  100  with a general curable adhesive. As a result, in the present embodiment, it is possible to improve a detection accuracy of the storage amount of the ink INK stored in the ink tank  100 . 
     Further, in the present embodiment, an inner surface IF 1  of the outer wall  120   a  on a side opposite to the outer surface OF 1  and an inner surface IF 2  of the outer wall  120   b  on a side opposite to the outer surface OF 2  are subjected to the water-repellent treatment. Specifically, the water-repellent treatment is applied to a portion of the inner surface IF 1  of the outer wall  120   a  exposed to the space SP and a portion of the inner surface IF 2  of the outer wall  120   b  exposed to the space SP. That is, in the inner surface IF 1  of the outer wall  120   a , a portion to be adhered to the outer walls  120   c ,  120   d  and  120   e  and a portion to be adhered to the partition walls  122   a  and  122   b  are not subjected to the water-repellent treatment. The water-repellent treatment is, for example, a water-repellent treatment with a silicone-based coating. The water-repellent treatment is not limited to the water-repellent treatment with the silicone-based coating. For example, the water-repellent treatment may be a water-repellent treatment with a fluorine-based coating. 
     Here, in the present embodiment, in the inner surface IF 1  of the outer wall  120   a , a lowercase alphabet “a” is added to an end of a code of the inner surface IF 1  of the first arrangement portion PP 1 . Similarly, in the inner surface IF 2  of the outer wall  120   b , a lowercase alphabet “a” is added to an end of a code of the inner surface IF 2  of the second arrangement portion PP 2 . 
     A range in which the water-repellent treatment is applied is not limited to the examples described above as long as the inner surface IF 1   a  of the first arrangement portion PP 1  of the outer wall  120   a  and the inner surface IF 2   a  of the second arrangement portion PP 2  of the outer wall  120   b  are subjected to the water-repellent treatment. For example, the inner surface IF 1   a  of the first arrangement portion PP 1  and the inner surface IF 2   a  of the second arrangement portion PP 2  may be subjected to the water-repellent treatment by the fluorine-based coating or the water-repellent treatment by the silicone-based coating. 
     In the present embodiment, since the inner surface IF 1   a  of the first arrangement portion PP 1  and the inner surface IF 2   a  of the second arrangement portion PP 2  are subjected to the water-repellent treatment, it is possible to improve water repellency of the inner surface IF 1   a  of the first arrangement portion PP 1  and the inner surface IF 2   a  of the second arrangement portion PP 2 . Thereby, in the present embodiment, it is possible to suppress adhesion of the ink INK to the inner surfaces IF 1   a  and IF 2   a  as compared with a case where the inner surfaces IF 1   a  and IF 2   a  are not subjected to the water-repellent treatment. 
     For example, in a case where the ink INK is attached to the inner surfaces IF 1   a  and IF 2   a , the detection accuracy of the storage amount of the ink INK stored in the ink tank  100  may decrease as compared with a case where the ink INK is not attached to the inner surfaces IF 1   a  and IF 2   a . In the present embodiment, since it is possible to suppress the adhesion of the ink INK to the inner surfaces IF 1   a  and IF 2   a , it is possible to improve the detection accuracy of the storage amount of the ink INK stored in the ink tank  100 . 
     Further, in the present embodiment, as described above, in the inner surface IF 1  of the outer wall  120   a , the portion that adheres to the outer walls  120   c ,  120   d  and  120   e  and the portion that adheres to the partition walls  122   a  and  122   b  are not subjected to the water-repellent treatment. Therefore, in the present embodiment, it is possible to suppress a decrease in strength of adhesion between the outer walls  120   c ,  120   d  and  120   e  and the outer wall  120   a , and a decrease in strength of adhesion between the partition walls  122   a  and  122   b  and the outer wall  120   a.    
     Here, when the ink INK is ejected from the ejection section  30   a  of the head unit  30 , the storage amount of the ink INK in the ink tank  100  is reduced, so that the liquid level L of the ink INK is lowered. In the present embodiment, the management unit  2  having the tank unit  10  and the detection circuit  20  detects the liquid level L of the ink INK by the detection circuit  20 , so that the storage amount of the ink INK in the ink tank  100 , that is, a remaining amount of the ink INK can be grasped. The management unit  2  may include a notification portion that notifies a user of the ink jet printer  1  of the remaining amount of the ink INK. For example, the notification portion may notify the user of the ink jet printer  1  of the remaining amount of the ink INK by displaying the remaining amount of the ink INK. In an aspect in which the management unit  2  includes the notification portion, by notifying the user of the ink jet printer  1  of the remaining amount of the ink INK, it is possible to prevent the ink INK from running out at an undesired timing. 
     Next, with reference to  FIG.  8   , the outline of a method for detecting the storage amount of the ink INK in the ink tank  100  will be explained. 
       FIG.  8    is an explanatory diagram for explaining the outline of a method for detecting the storage amount of the ink INK in the ink tank  100 . Note that  FIG.  8    shows a cross section of the ink tank  100  and the FPC  200  taken along the line A 1 -A 2  shown in  FIG.  3   . Also in  FIG.  8   , in order to make the figure easier to see, similarly to  FIG.  7   , the elements located in the +Z direction with respect to the partition wall  122   b , the support portion  130  and the like are not shown. 
     A capacitor CCa is composed of the input electrode  210 , the detection electrode  220   a , and a dielectric existing between the input electrode  210  and the detection electrode  220   a . For example, the double-sided tape  260 , the outer wall  120   a , one or both of the ink INK and air, and the outer wall  120   b  correspond to main dielectrics existing between the input electrode  210  and the detection electrode  220   a . A capacitance of the capacitor CCa is represented, for example, by a combined capacitance of a plurality of capacitors divided based on a plurality of dielectrics existing between the input electrode  210  and the detection electrode  220   a.    
     In  FIG.  8   , it is assumed that the capacitor CCa is divided into capacitors Ca 1  and Ca 5  having the double-sided tape  260  as a dielectric, a capacitor Ca 2  having the outer wall  120   a  as a dielectric, a capacitor Ca 3 , and a capacitor Ca 4  having the outer wall  120   b  as a dielectric. The capacitor Ca 3  is a capacitor in which one or both of the ink INK and the air among the dielectrics existing between the input electrode  210  and the detection electrode  220   a  are used as the dielectric. 
     A capacitor CCb is composed of the input electrode  210  and the detection electrode  220   b  and a dielectric existing between the input electrode  210  and the detection electrode  220   b . The dielectric existing between the input electrode  210  and the detection electrode  220   b  is the same as the dielectric existing between the input electrode  210  and the detection electrode  220   a . For example, the capacitor CCb is divided into capacitors Cb 1  and Cb 5  having the double-sided tape  260  as a dielectric, a capacitor Cb 2  having the outer wall  120   a  as a dielectric, a capacitor Cb 3 , and a capacitor Cb 4  having the outer wall  120   b  as a dielectric. 
     For example, a capacitance CC of each of the capacitors CCa and CCb is represented by an equation (1) using capacitances C 1 , C 2 , C 3 , C 4  and C 5  of a plurality of capacitors obtained by dividing each of the capacitors CCa and CCb. 
         CC= 1/(1/ C 1+1/ C 2+1/ C 3+1/ C 4+1/ C 5)  (1)
 
     In the present embodiment, it is assumed that the detection electrodes  220   a  and  220   b  have the same size, so that C 1  in the equation (1) indicates the capacitance of the capacitors Ca 1  and Cb 1 , and C 2  indicates the capacitance of the capacitors Ca 2  and Cb 2 . C 4  in the equation (1) indicates the capacitance of the capacitors Ca 4  and Cb 4 , and C 5  indicates the capacitance of the capacitors Ca 5  and Cb 5 . When the equation (1) indicates the capacitance C of the capacitor CCa, C 3  indicates the capacitance of the capacitor Ca 3 , and when the equation (1) indicates the capacitance C of the capacitor CCb, C 3  indicates the capacitance of the capacitor Cb 3 . 
     In the below, the capacitances CC, C 1 , C 2 , C 3 , C 4  and C 5  may be collectively referred to as the capacitance C. For example, the capacitance C [F] is represented by an equation (2). 
         C=ε 0*ε1* S/d   (2)
 
     Note that “*” in the equation (2) indicates multiplication. S in the equation (2) indicates an area of the detection electrode  220   a  or  220   b , and d indicates a distance between electrodes of the capacitor. In the example shown in  FIG.  8   , a length of the dielectric of the capacitor in the Y direction corresponds to a distance d. ε0 in the equation (2) indicates a dielectric constant of a vacuum, and ε1 indicates a relative permittivity of the dielectric of the capacitor. 
     As shown in the equation (2), the capacitance C increases in proportion to the relative permittivity ε1 of the dielectric of the capacitor. Among the capacitors Ca 1  to Ca 5  and Cb 1  to Cb 5 , in the capacitors other than the capacitors Ca 3  and Cb 3 , the relative permittivity E 1  does not change even if the storage amount of the ink INK in the ink tank  100  changes. On the other hand, in the capacitors Ca 3  and Cb 3  having one or both of the ink INK and the air as a dielectric, the relative permittivity E 1  differs depending on the storage amount of the ink INK in the ink tank  100 . 
     For example, in the capacitor Ca 3 , the relative permittivity ε 1  changes depending on a ratio of the ink INK and the air existing between the input electrode  210  and the detection electrode  220   a . The relative permittivity ε 1  of the ink INK is larger than the relative permittivity ε 1  of the air. For example, the relative permittivity ε 1  of the ink INK varies depending on a material of the ink INK, and is about 80 if it is considered to be close to the relative permittivity of water. Further, the relative permittivity  61  of the air is approximately 1. 
     As described above, in the capacitors Ca 3  and Cb 3 , the capacitance C 3  changes depending on the storage amount of the ink INK in the ink tank  100 . For example, an influence of a change in the capacitance C 3  of the capacitor Ca 3  on the capacitor CCa is large in a case where the capacitance C of the capacitor other than the capacitor Ca 3  is large as compared with a case where the capacitance C of the capacitor other than the capacitor Ca 3  is small. Similarly, an influence of the change in the capacitance C 3  of the capacitor Cb 3  on the capacitor CCb is large in a case where the capacitance C of the capacitor other than the capacitor Cb 3  is large as compared with a case where the capacitance C of the capacitor other than the capacitor Cb 3  is small. 
     For example, the capacitance C increases in proportion to a reciprocal of the distance d between the electrodes of the capacitor. That is, in a case where a length of the dielectric of the capacitor in the Y direction is small, the capacitance C is large as compared with a case where the length of the dielectric of the capacitor in the Y direction is large. Therefore, in the present embodiment, as explained in  FIG.  7   , the thickness T 1  of the first arrangement portion PP 1  of the outer wall  120   a  is thinner than the thickness T 2  of the second arrangement portion PP 2  of the outer wall  120   b  and the thickness T 3  of the outer wall  120   d . The thickness T 1  of the first arrangement portion PP 1  is not particularly limited as long as the thickness T 1  is thinner than one of the thicknesses T 2  and T 3 . For example, the thickness T 1  of the first arrangement portion PP 1  may be about 0.01 mm, and the thickness T 2  of the second arrangement portion PP 2  may be about 1 mm. 
     In the present embodiment, since the thickness T 1  of the first arrangement portion PP 1  is thinner than the thicknesses T 2  and T 3 , the capacitance C 1  of the capacitors Ca 1  and Cb 1  can be increased as compared with a case where the thickness T 1  of the first arrangement portion PP 1  is the same as the thickness T 2  or the thickness T 3 . Thereby, in the present embodiment, it is possible to accurately detect the change in the capacitance C 3  of each of the capacitors Ca 3  and Cb 3 . As a result, in the present embodiment, it is possible to improve the detection accuracy of the storage amount of the ink INK in the ink tank  100 . 
     Further, in the present embodiment, it is assumed that the dielectric constant of the first arrangement portion PP 1  of the outer wall  120   a  is higher than the dielectric constant of the second arrangement portion PP 2  of the outer wall  120   b  and the dielectric constant of the outer wall  120   d . In this case, for example, the capacitance C 1  of the capacitors Ca 1  and Cb 1  can be increased as compared with a case where the outer wall  120   a  is formed of a material having the same dielectric constant as the outer wall  120   b  or  120   d.    
     In the example shown in  FIG.  8   , the terminal TMg of the shield wiring  240  is grounded through any of the external contacts CTg 1  to CTg 6  in order to reduce the transmission of a noise to the input electrode  210 , the detection electrodes  220   a  and  220   b  and the like. 
     The terminal TMt 1  of the input electrode  210  is electrically coupled to the AC power supply ACP via the external contact CTt 1 . The AC power supply ACP outputs, for example, an AC signal including a pulse having an amplitude of 3.3 [V] as an input signal Vin to the input electrode  210 . For example, the input signal Vin is transmitted to the detection electrode  220   a  as a detection signal Vout 1  via the capacitor CCa, and is transmitted to the detection electrode  220   b  via the capacitor CCb as a detection signal Vout 2 . The terminal TMr 1  of the detection electrode  220   a  is electrically coupled to the input terminal IN 1  of the selection circuit  21  described later in  FIG.  10    via the external contact CTr 1 , and the terminal TMr 2  of the detection electrode  220   b  is electrically coupled to the input terminal IN 2  of the selection circuit  21  via the external contact CTr 2 . As a result, the detection signals Vout 1  and Vout 2  are input to the selection circuit  21 . The detection signals Vout 1  and Vout 2  are examples of an “electric signal”. 
     The amplitude of the detection signal Vout 1  is large in a case where the capacitance CC of the capacitor CCa is large as compared with a case where the capacitance CC of the capacitor CCa is small. For example, the amplitude of the detection signal Vout 1  is large in a case where the capacitance C 3  of the capacitor Ca 3  is large as compared with a case where the capacitance C 3  of the capacitor Ca 3  is small. That is, in a case where a space between the input electrode  210  and the detection electrode  220   a  is filled with the ink INK, the amplitude of the detection signal Vout 1  is large as compared with a case where the space between the input electrode  210  and the detection electrode  220   a  is filled with the air. Similarly, in a case where a space between the input electrode  210  and the detection electrode  220   b  is filled with the ink INK, the amplitude of the detection signal Vout 2  is large as compared with a case where the space between the input electrode  210  and the detection electrode  220   b  is filled with the air. 
     In the example shown in  FIG.  8   , since the liquid level L of the ink INK is located between a liquid level range LV 1  and a liquid level range LV 2 , the amplitude of the detection signal Vout 1  is larger than the amplitude of the detection signal Vout 2 . The liquid level range LV 1  corresponds to a position of the detection electrode  220   a  in the Z direction, and is a range from the side in the −Z direction to the side in the +Z direction of the two sides of the detection electrode  220   a  along the X direction. Further, the liquid level range LV 2  corresponds to a position of the detection electrode  220   b  in the Z direction, and is a range from the side in the −Z direction to the side in the +Z direction of the two sides of the detection electrode  220   b  along the X direction. 
     Next, with reference to  FIG.  9   , a relationship between the liquid level L of the ink INK in the ink tank  100  and the detection signals Vout 1  and Vout 2  will be explained. 
       FIG.  9    is an explanatory diagram for explaining the relationship between the liquid level L of the ink INK in the ink tank  100  and the detection signals Vout 1  and Vout 2 . Hereinafter, the detection signals Vout 1  and Vout 2  may be collectively referred to as detection signals Vout. A horizontal axis in the figure indicates a position of the liquid level L of the ink INK in the Z direction. For example, the position H 2  is a position in the +Z direction with respect to the position H 1 . The liquid level range LV 2  is located in the +Z direction with respect to the liquid level range LV 1 . That is, the liquid level range LV 2  is located above the liquid level range LV 1 . A vertical axis of the figure shows a magnitude of the detection signal Vout, which is a voltage of the detection electrode  220 . The magnitude of the detection signal Vout may be, for example, an amplitude of the detection signal Vout or an effective value of the detection signal Vout. A voltage VH is larger than a voltage Vth, and the voltage Vth is larger than a voltage VL. 
     The voltage Vth is a threshold voltage when the magnitude of the detection signal Vout is expressed by two values such as a high level and a low level. For example, the voltage Vth may be a central voltage between the voltages VL and VH, a voltage closer to the voltage VL than the voltage VH between the voltages VL and VH, or a voltage closer to the voltage VH than the voltage VL between the voltages VL and VH. 
     When the space between the input electrode  210  and the detection electrode  220   a  is filled with the air and there is no ink INK between the input electrode  210  and the detection electrode  220   a , the magnitude of the detection signals Vout 1  and Vout 2  is the voltage VL. The magnitude of the detection signal Vout 1  increases when a proportion of the ink INK existing between the input electrode  210  and the detection electrode  220   a  increases. For example, when the magnitude of the detection signal Vout 1  is the voltage Vth, it can be considered that the liquid level L of the ink INK exists in the liquid level range LV 1  including the position H 1  where the detection electrode  220   a  is arranged. When the space between the input electrode  210  and the detection electrode  220   a  is filled with the ink INK and there is no air between the input electrode  210  and the detection electrode  220   a , the magnitude of the detection signal Vout 1  is the voltage VH. 
     The magnitude of the detection signal Vout 2  increases when a proportion of the ink INK existing between the input electrode  210  and the detection electrode  220   b  increases. For example, when the magnitude of the detection signal Vout 2  is the voltage Vth, it can be considered that the liquid level L of the ink INK exists in the liquid level range LV 2  including the position H 2  where the detection electrode  220   b  is arranged. When the space between the input electrode  210  and the detection electrode  220   b  is filled with the ink INK and there is no air between the input electrode  210  and the detection electrode  220   b , the magnitude of the detection signal Vout 2  is the voltage VH. 
     Next, the detection circuit  20  will be explained with reference to  FIG.  10   . 
       FIG.  10    is a circuit diagram of the detection circuit  20 . Note that  FIG.  10    is an excerpt of a portion of the management unit  2  that manages the storage amount of the ink INK in one of the plurality of ink tanks  100  of the tank unit  10 . Further, in  FIG.  10   , for easy explanation, the tank unit  10  is illustrated by an equivalent circuit represented by the capacitors CCa and CCb. 
     The detection circuit  20  includes the selection circuit  21 , a bias circuit  22 , a buffer circuit  23 , a band pass filter (BPF)  24 , a sample and hold (SH) circuit  25 , a low pass filter (LPF)  26 , an amplifier circuit  27 , and an analog to digital converter (ADC)  28 . 
     The selection circuit  21  includes the input terminals IN 1  and IN 2  and an output terminal OT. The selection circuit  21  electrically couples one of the input terminals IN 1  and IN 2  to the output terminal OT and grounds the other of the input terminals IN 1  and IN 2  according to control by the control unit  4 . 
     For example, the input terminal IN 1  of the selection circuit  21  is electrically coupled to the external contact CTr 1  in contact with the terminal TMr 1 , and the input terminal IN 2  of the selection circuit  21  is electrically coupled to the external contact CTr 2  in contact with the terminal TMr 2 . That is, the input terminal IN 1  of the selection circuit  21  is electrically coupled to the detection electrode  220   a  via the external contact CTr 1  and the terminal TMr 1 , and the input terminal IN 2  of the selection circuit  21  is electrically coupled to the detection electrode  220   b  via the external contact CTr 2  and the terminal TMr 2 . The output terminal OT of the selection circuit  21  is electrically coupled to the buffer circuit  23  via the bias circuit  22 . 
     That is, the selection circuit  21  outputs the detection signal Vout selected according to the control by the control unit  4  out of the detection signal Vout 1  received at the input terminal IN 1  and the detection signal Vout 2  received at the input terminal IN 2  to the buffer circuit  23  from the output terminal OT. In this way, the selection circuit  21  switches the detection signal Vout output to the buffer circuit  23  between the detection signal Vout 1  and the detection signal Vout 2 . 
     The bias circuit  22  biases, for example, the output terminal OT of the selection circuit  21 , i.e., an input of the buffer circuit  23 , to a predetermined bias voltage between a power supply voltage and a ground voltage. The bias circuit  22  may bias the input of the buffer circuit  23  by a predetermined bias current. 
     The buffer circuit  23  outputs the detection signal Vout output from the selection circuit  21  to the BPF  24 . As described above, the detection signal Vout output from the selection circuit  21  is biased to the predetermined bias voltage by the bias circuit  22 . In the buffer circuit  23 , for example, an input impedance is higher than an output impedance. For example, the buffer circuit  23  is used for impedance conversion. 
     The BPF  24  selectively passes components in a predetermined frequency range and removes other components. For example, the BPF  24  outputs, to the SH circuit  25 , a signal of a component in a predetermined frequency range of the detection signal Vout output from the buffer circuit  23 . 
     The SH circuit  25  receives, for example, the input signal Vin output from the AC power supply ACP and the signal output from the BPF  24 . Then, the SH circuit  25  samples the signal output from the BPF  24  in a cycle based on a cycle of the input signal Vin, and holds a voltage value of the sampled signal until an operation of the ADC  28  is completed. Further, the SH circuit  25  outputs the sampled signal to the LPF  26 . 
     The LPF  26  removes a component having a frequency higher than a predetermined threshold value and allows a component having a frequency equal to or lower than the predetermined threshold value to pass therethrough. For example, the LPF  26  removes a component having a frequency higher than the predetermined threshold value from the signals output from the SH circuit  25 , and outputs a signal of a component having a frequency equal to or lower than the predetermined threshold value to the amplifier circuit  27 . Therefore, the signal that has passed through the LPF  26  is a signal from which a noise and the like of components having a frequency higher than the predetermined threshold value have been removed. 
     The amplifier circuit  27  amplifies the signal output from the LPF  26  at a predetermined amplification factor, and outputs the amplified signal to the ADC  28 . The signal output from the amplifier circuit  27  to the ADC  28  is an analog signal. 
     The ADC  28  converts the analog signal output from the amplifier circuit  27  into a digital signal. Then, the ADC  28  outputs the digital signal converted from the analog signal to the control unit  4  as an output signal Do. The output signal Do is a digital signal indicating a magnitude of the detection signal Vout selected by the selection circuit  21  from the detection signals Vout 1  and Vout 2 . In this way, the detection circuit  20  detects the storage amount of the ink INK in the ink tank  100  by detecting the magnitudes of the detection signals Vout 1  and Vout 2 . Although the details will be described later in  FIG.  14   , for example, the control unit  4  specifies the storage amount of the ink INK in the ink tank  100  based on the output signal Do output from the detection circuit  20 . 
     The configuration of the detection circuit  20  is not limited to the example shown in  FIG.  10   . For example, the detection circuit  20  may include, instead of the ADC  28 , a comparator for comparing whether or not an output voltage of the amplifier circuit  27  is equal to or higher than a predetermined value. Further, for example, when the number of the detection electrode  220  is one, the selection circuit  21  may be omitted. Alternatively, when the number of the detection electrodes  220  is three or more, for example, the selection circuit  21  includes three or more input terminals IN having a one-to-one correspondence with the three or more detection electrodes  220 . Then, the selection circuit  21  electrically couples one of the three or more input terminals IN to the output terminal OT, and grounds the other input terminals IN. 
     Next, an overall configuration of the FPC  200  will be explained with reference to  FIG.  11   . 
       FIG.  11    is a plan view showing an example of the FPC  200 . Note that  FIG.  11    is a plan view of the FPC  200  in a state of not being adhered to the ink tank  100 . In  FIG.  11   , in order to facilitate a correspondence with  FIG.  3   , the +X direction, the +Y direction, and the +Z direction with respect to the detection electrode  220  are the same as those in  FIG.  3   . Further, in  FIG.  11   , in order to make the figure easier to see, the FPC  200  is described by being divided into a figure of the first cover film layer  201  and the first conductor layer  202 , a figure of the base material layer  203 , and a figure of the second conductor layer  204  and the second cover film layer  205 . 
     The FPC  200  is, for example, an FPC capable of mounting components on both sides of the base material layer  203 . For example, the first conductor layer  202  is provided in one surface of the base material layer  203 , and the second conductor layer  204  is provided in the other surface of the base material layer  203 . 
     The first conductor layer  202  includes, for example, the input electrode  210 , the wiring  212  of the input electrode  210 , the detection electrode  220   a , the wiring  222   a  of the detection electrode  220   a , the detection electrode  220   b , the wiring  222   b  of the detection electrode  220   b , and the shield wirings  240   a ,  240   b  and  240   c . The input electrodes  210 , the detection electrodes  220   a  and  220   b , the wirings  212 ,  222   a  and  222   b , and the shield wirings  240   a ,  240   b  and  240   c  each extend in the X direction. 
     For example, a distance D 12  between the input electrode  210  and the detection electrode  220  is larger than the width W 10   z  of the input electrode  210  in the Z direction. Further, for example, a width W 12   z  of the wiring  212  of the input electrode  210  in the Z direction is smaller than the width W 10   z  of the input electrode  210  in the Z direction, and the width W 10   z  of the input electrode  210  in the Z direction is smaller than the width W 10   x  of the input electrode  210  in the X direction. Further, the width W 20   az  of the wiring  222   a  of the detection electrode  220   a  in the Z direction is smaller than the width W 20   az  of the detection electrode  220   a  in the Z direction, and the width W 20   az  of the detection electrode  220   a  in the Z direction is smaller than the width W 20   ax  of the detection electrode  220   a  in the X direction. Similarly, the width W 20   bz  of the wiring  222   b  of the detection electrode  220   b  in the Z direction is smaller than the width W 20   bz  of the detection electrode  220   b  in the Z direction, and the width W 20   bz  of the detection electrode  220   b  in the Z direction is smaller than the width W 20   bx  of the detection electrode  220   b  in the X direction. 
     In the present embodiment, it is assumed that the detection electrodes  220   a  and  220   b  have substantially the same shape and the detection electrodes  220   a  and  220   b  have substantially the same size. For example, the width W 20   az  of the detection electrode  220   a  in the Z direction is substantially equal to the width W 20   bz  of the detection electrode  220   b  in the Z direction, and the width W 20   ax  in the X direction of the detection electrode  220   a  is substantially equal to the width W 20   bx  of the detection electrode  220   b  in the X direction. When the detection electrodes  220   a  and  220   b  have substantially the same shape, it is considered that electrical characteristics of the capacitor CCa including the detection electrode  220   a  and the capacitor CCb including the detection electrode  220   b  are substantially the same. Therefore, in the present embodiment, the detection circuit  20  using the detection signal Vout 1  input from the detection electrode  220   a  and the detection circuit  20  using the detection signal Vout 2  input from the detection electrode  220   b  can be shared. As a result, in the present embodiment, it is possible to suppress an increase in the number or circuit scale of the detection circuits  20  corresponding to one ink tank  100 . 
     If the detection circuit  20  can be shared between the detection electrodes  220   a  and  220   b , for example, the size of the detection electrode  220   a  may be different from the size of the detection electrode  220   b . For example, a difference between the width W 20   az  of the detection electrode  220   a  in the Z direction and the width W 20   bz  of the detection electrode  220   b  in the Z direction may be equal to or less than a first value, and a difference between the width W 20   ax  of the detection electrode  220   a  in the X direction and the width W 20   bx  of the detection electrode  220   b  in the X direction may be equal to or less than a second value. The first value and the second value are, for example, allowable values for a difference in size between the detection electrodes  220   a  and  220   b  when the detection circuit  20  is shared between the detection electrodes  220   a  and  220   b . Further, when the detection circuits  20  are individually provided for the detection electrodes  220   a  and  220   b , the detection electrodes  220   a  and  220   b  may not have substantially the same shape or may not have substantially the same size. 
     In the below, the width W 20   az  of the detection electrode  220   a  in the Z direction and the width W 20   bz  of the detection electrode  220   b  in the Z direction may be collectively referred to as widths W 20   z , and the width W 20   ax  of the detection electrode  220   a  in the X direction and the width W 20   bx  of the detection electrode  220   b  in the X direction may be collectively referred to as widths W 20   x.    
     Further, the shield wiring  240   c  is arranged between the detection electrode  220   a  and the detection electrode  220   b , and between the wiring  222   a  and the wiring  222   b . In the present embodiment, it is assumed that a width W 40   cz  of the shield wiring  240   c  in the Z direction is equal to or greater than the width W 20   az  of the detection electrode  220   a  in the Z direction and equal to or greater than the width W 20   bz  of the detection electrode  220   b  in the Z direction. When the width W 40   cz  of the shield wiring  240   c  is equal to or greater than the width W 20  of the detection electrode  220 , an interference between the two detection electrodes  220   a  and  220   b  can be reduced as compared with a case where the width W 40   cz  of the shield wiring  240   c  is less than the width W 20  of the detection electrode  220 . 
     Further, the bent portion BP 1  includes a part of the wiring  212  of the input electrode  210 , a part of the shield wiring  240   a , and a part of the shield wiring  240   b , and does not include the input electrode  210 . Similarly, the bent portion BP 2  includes a part of the wiring  222   a  of the detection electrode  220   a , a part of the wiring  222   b  of the detection electrode  220   b , a part of the shield wiring  240   a , and a part of the shield wiring  240   b , and does not include the detection electrodes  220   a  and  220   b . That is, the FPC  200  is bent along the outer periphery of the ink tank  100  at a portion where the wiring  212  is arranged and a portion where the wiring  222   a  is arranged. 
     As described above, the bent portion BP 1  does not include the input electrode  210  having a width wider than that of the wiring  212 . Therefore, in the present embodiment, a rigidity of the bent portion BP 1  can be made lower than that of a portion where the input electrode  210  is arranged. Similarly, in the present embodiment, a rigidity of the bent portion BP 2  can be made lower than that of a portion where the detection electrode  220  is arranged. As a result, in the present embodiment, the FPC  200  can be easily bent along the outer periphery of the ink tank  100  at the bent portions BP 1  and BP 2 . 
     The second conductor layer  204  includes, for example, the shield wiring  240   d , a lead wiring  242   d  of the shield wiring  240   d , the shield wiring  240   e , a lead wiring  242   e  of the shield wiring  240   e , and the plurality of terminals TM. The shield wiring  240   d  is electrically coupled to one or more terminals TMg of the plurality of terminals TMg via the lead wiring  242   d , and the shield wiring  240   e  is electrically coupled to one or more terminals TMg of the plurality of terminals TMg via the lead wiring  242   e . For example, the shield wiring  240   d  is electrically coupled to the terminals TMg 4  and TMg 5  by the lead wiring  242   d . Further, for example, the shield wiring  240   e  is electrically coupled to the terminal TMg 6  by the lead wiring  242   e.    
     The lead wirings  242   d  and  242   e  are formed of the same material as the input electrode  210 . In the present embodiment, it is assumed that the shield wiring  240   d  and the lead wiring  242   d  are integrally formed, and the shield wiring  240   e  and the lead wiring  242   e  are integrally formed. In this case, the lead wiring  242   d  is directly coupled to the shield wiring  240   d , and the lead wiring  242   e  is directly coupled to the shield wiring  240   e . The shield wiring  240   d , the lead wiring  242   d , and the terminals TMg 4  and TMg 5  may be integrally formed. Similarly, the shield wiring  240   e , the lead wiring  242   e , and the terminal TMg 6  may be integrally formed. 
     The shield wiring  240   d  includes, for example, a region that overlaps the entire input electrode  210  and at least a part of the wiring  212  in a plan view from the +Y direction. For example, a width W 40   dx  of the shield wiring  240   d  in the X direction is larger than the width W 10   x  of the input electrode  210  in the X direction. Further, a width W 40   dz  of the shield wiring  240   d  in the Z direction is larger than the width W 10   z  of the input electrode  210  in the Z direction. That is, the shield wiring  240   d  extends in the X direction with a constant width W 40   dz . The shield wiring  240   d  may extend in the X direction with a substantially constant width W 40   dz  including an error. 
     In the example shown in  FIG.  11   , the bent portion BP 1  is located between two edge portions EP 3   d  and EP 4   d  of the shield wiring  240   d . The two edge portions EP 3   d  and EP 4   d  of the shield wiring  240   d  are, for example, edge portions that are separated from each other in the X direction among edge portions that are grasped in a plan view from the +Y direction. The edge portion EP 4   d  located in the +X direction with respect to the edge portion EP 3   d  may be located in the −X direction with respect to the bent portion BP 1  in a range including a region where the shield wiring  240   d  overlaps the entire input electrode  210  in a plan view from the +Y direction. 
     The shield wiring  240   e  includes, for example, a region that overlaps the entire detection electrode  220   a , the entire detection electrode  220   b , at least a part of the wiring  222   a , and at least a part of the wiring  222   b  in a plan view from the +Y direction. For example, a width W 40   ex  of the shield wiring  240   e  in the X direction is larger than both the width W 20   ax  of the detection electrode  220   a  in the X direction and the width W 20   bx  of the detection electrode  220   b  in the X direction. Further, a width W 40   ez  of the shield wiring  240   e  in the Z direction is larger than a sum of the width W 20   az  of the detection electrode  220   a  in the Z direction and the width W 20   bz  of the detection electrode  220   b  in the Z direction. That is, the shield wiring  240   e  extends in the X direction with a constant width W 40   ez . The shield wiring  240   e  may extend in the X direction with a substantially constant width W 40   ez  including an error. 
     In the example shown in  FIG.  11   , the bent portion BP 2  is located between two edge portions EP 3   e  and EP 4   e  of the shield wiring  240   e . The two edge portions EP 3   e  and EP 4   e  of the shield wiring  240   e  are, for example, edge portions that are separated from each other in the X direction among edge portions that are grasped in a plan view from the +Y direction. The edge portion EP 4   e  located in the −X direction with respect to the edge portion EP 3   e  may be located in the +X direction with respect to the bent portion BP 2  in a range including a region where the shield wiring  240   e  overlaps the entire detection electrode  220  in a plan view from the +Y direction. 
     Here, in  FIG.  11   , the +Y direction corresponds to a direction perpendicular to a surface of the input electrode  210  facing the outer wall  120   a  and a direction perpendicular to a surface of the detection electrode  220  facing the outer wall  120   b . Further, the X direction corresponds to an extending direction of the FPC  200 . 
     Further, in a terminal arrangement in which the terminals TMt 1 , TMr 1 , TMg 1 , TMg 2  and TMg 3  are arranged, the terminal TMt 1  is located at one end of the terminal arrangement and the terminal TMr 1  is located at the other end of the terminal arrangement. 
     Further, the number of terminals TMg located between the terminal TMt 1  and one of the terminals TMr 1  and TMr 2  is larger than the number of terminals TMg located between the terminals TMr 1  and TMr 2 . In the example shown in  FIG.  11   , the number of terminals TMg located between terminals TMr 1  and TMr 2  is two of the terminals TMg 3  and TMg 6 . The number of terminals TMg located between the terminal TMt 1  and the terminal TMr 1  is three of the terminals TMg 1 , TMg 2 , and TMg 3 . Further, the number of terminals TMg located between the terminals TMt 1  and the terminal TMr 2  is four of the terminals TMg 1 , TMg 2 , TMg 4  and TMg 5 . In the present embodiment, by increasing the number of terminals TMg located between the terminal TMt 1  and one of the terminals TMr 1  and TMr 2 , it is possible to reduce an interference between the terminal TMt 1  and the one of the terminals TMr 1  and TMr 2 . 
     When focusing on a distance between the terminals TM rather than the number of the terminals TMg, a distance between the terminal TMt 1  and one of the terminals TMr 1  and TMr 2  is larger than a distance between the terminals TMr 1  and TMr 2 . The distance between the terminals TM may be a distance between a center of one terminal TM and a center of the other terminal TM of two terminals TM, or may be a shortest distance between the two terminals TM. In this case, by increasing the distance between the terminal TMt 1  and the one of the terminals TMr 1  and TMr 2 , it is possible to reduce the interference between the terminal TMt 1  and the one of the terminals TMr 1  and TMr 2 . 
     Through holes TH 1 , TH 2   a , TH 2   b , TH 4   a , TH 4   b  and TH 4   c  penetrating through the base material layer  203  are formed in the base material layer  203 . In the below, the through holes TH 1 , TH 2   a , TH 2   b , TH 2   a , TH 4   a , TH 4   b  and TH 4   c  may be collectively referred to as through holes TH. In the example shown in  FIG.  11   , the number of the through holes TH is ten, but the number of the through holes TH is not limited to ten. 
     A through wiring TW 1  inserted through the through hole TH 1  is coupled to the terminal TMt 1  and the wiring  212 . The wiring  212  couples the through wiring TW 1  and the input electrode  210 . That is, the input electrode  210  is electrically coupled to the terminal TMt 1  by the through wiring TW 1 . A through wiring TW 2   a  inserted through the through hole TH 2   a  couples the terminal TMr 1  and the wiring  222   a . The wiring  222   a  couples the through wiring TW 2   a  and the detection electrode  220   a . That is, the detection electrode  220   a  is electrically coupled to the terminal TMr 1  by the through wiring TW 2   a . A through wiring TW 2   b  inserted through the through hole TH 2   b  couples the terminal TMr 2  and the wiring  222   b . The wiring  222   b  couples the through wiring TW 2   b  and the detection electrode  220   b . That is, the detection electrode  220   b  is electrically coupled to the terminal TMr 2  by the through wiring TW 2   b.    
     Further, the shield wiring  240   a  is electrically coupled to the terminals TMg 1 , TMg 2  and TMg 3  by through wiring TW 4   a  inserted through the through hole TH 4   a . The shield wiring  240   b  is electrically coupled to the terminals TMg 4 , TMg 5  and TMg 6  by the through wiring TW 4   b  inserted through the through hole TH 4   b . The shield wiring  240   c  is electrically coupled to the terminal TMg 6  by the through wiring TW 4   c  inserted through the through hole TH 4   c . In the below, the through wiring TW 1 , TW 2   a , TW 2   b , TW 4   a , TW 4   b  and TW 4   c  may be collectively referred to as through wirings TW. 
     Here, the second conductor layer  204  including the shield wirings  240   d  and  240   e , the plurality of terminals TM and the like is covered with the second cover film layer  205  except for the plurality of terminals TM. That is, the plurality of terminals TM are exposed to an outside of the FPC  200 . Thereby, in the present embodiment, it is possible to realize contacts by spring contacts or the like between the plurality of terminals TM and the plurality of external contacts CT. In the FPC  200 , at least a part of a terminal arrangement region AR including the plurality of terminals TM is located between the input electrode  210  and the detection electrode  220   a . For example, in the FPC  200 , the input electrode  210  is located in the −X direction with respect to the terminal arrangement region AR, and the detection electrode  220  is located in the +X direction with respect to the terminal arrangement region AR. In the present embodiment, since the plurality of terminals TM are integrated between the input electrode  210  and the detection electrode  220   a , it is possible to reduce a size of the external substrate or the like provided with the plurality of external contacts CT in contact with the plurality of terminals TM. 
     As described above, in the present embodiment, the input electrode  210  and the detection electrodes  220   a  and  220   b  are provided in one FPC  200 . Therefore, in the present embodiment, for example, the FPC  200  can be easily attached to the ink tank  100  as compared with an aspect in which the input electrode  210  and the detection electrode  220  are provided in two different FPCs, respectively. Further, for example, in the aspect in which the input electrode  210  and the detection electrode  220  are provided in the two different FPCs, respectively, when the two FPCs are attached to the ink tank  100 , deviation of a position of the detection electrode  220  with respect to the input electrode  210  may become large. On the other hand, in the present embodiment, since one FPC  200  needs to be attached to the ink tank  100 , it is possible to reduce that the deviation of the position of the detection electrode  220  with respect to the input electrode  210  become large when the FPC  200  is attached to the ink tank  100 . 
     The arrangement of the plurality of positioning portions PT is not limited to the example shown in  FIG.  11   . For example, the ink tank  100  may include a fifth positioning portion PT and a seventh positioning portion PT in addition to the positioning portions PT 10  and PT 12 . In this case, the FPC  200  includes a sixth positioning portion PT that is fitted with the fifth positioning portion PT and an eighth positioning portion PT that is fitted with the seventh positioning portion PT. For example, in the X direction, at least a part of the terminal arrangement region AR may be located between the sixth positioning portion PT and the eighth positioning portion PT. That is, in the FPC  200 , two positioning portions PT penetrating through the FPC  200  may be formed at positions sandwiching the terminal arrangement region AR in the X direction. In this case, since the positioning portions PT are arranged so as to surround the terminal arrangement region AR, it is possible to further reduce deviation of the plurality of terminals TM from a predetermined positions with respect to the ink tank  100  when the FPC  200  is attached to the ink tank  100 . 
     Next, a relationship between a capacitance between the input electrode  210  and the detection electrode  220  and a size of the detection electrode  220  will be explained with reference to  FIGS.  12  and  13   . 
       FIG.  12    is an explanatory diagram for explaining an example of the relationship between the capacitance between the input electrode  210  and the detection electrode  220  and the size of the detection electrode  220 . A horizontal axis of the figure shows the position of the liquid level L of the ink INK in the Z direction, and a vertical axis of the figure shows the capacitance of the capacitors CCa and CCb. A solid line in the figure shows the capacitance of the capacitor CCa, and a broken line in the figure shows the capacitance of the capacitor CCb. Note that  FIG.  12    shows results of simulation of three patterns in which the width W 20   z  of the detection electrode  220  in the Z direction is “α”, “2*α” and “3*α”. α is a positive value. The width W 20   x  of the detection electrode  220  in the X direction is the same in the simulation of the three patterns. 
     In a case where the width W 20   z  of the detection electrode  220  in the Z direction is large, the capacitance when the space between the input electrode  210  and the detection electrode  220  is filled with the ink INK is large as compared with a case where the width W 20   z  of the detection electrode  220  in the Z direction is small. Even if the width W 20   z  of the detection electrode  220  in the Z direction changes, an amount of change in capacitance with respect to a predetermined amount of change in proportion of the ink INK existing between the input electrode  210  and the detection electrode  220  is almost constant. 
       FIG.  13    is an explanatory diagram for explaining another example of the relationship between the capacitance between the input electrode  210  and the detection electrode  220  and the size of the detection electrode  220 . As in  FIG.  12   , a horizontal axis in the figure shows the position of the liquid level L of the ink INK in the Z direction, and a vertical axis in the figure shows the capacitance of the capacitors CCa and CCb. A solid line in the figure shows the capacitance of the capacitor CCa, and a broken line in the figure shows the capacitance of the capacitor CCb. Note that  FIG.  13    shows results of simulation of three patterns in which the width W 20   x  of the detection electrode  220  in the X direction is “β”, “2*β”, and “3*β”. 0 is a positive value. The width W 20   z  of the detection electrode  220  in the Z direction is the same in the simulation of the three patterns. 
     In a case where the width W 20   x  of the detection electrode  220  in the X direction is large, the capacitance when the space between the input electrode  210  and the detection electrode  220  is filled with the ink INK is large as compared with a case where the width W 20   x  in the X direction of the detection electrode  220  is small. That is, in a case where an area of the detection electrode  220  is large, the capacitance when the space between the input electrode  210  and the detection electrode  220  is filled with the ink INK is large as compared with a case the area of the detection electrode  220  is small. 
     Further, in a case where the width W 20   x  of the detection electrode  220  in the X direction is large, an amount of change in capacitance with respect to a predetermined amount of change in proportion of the ink INK existing between the input electrode  210  and the detection electrode  220  is large as compared with a case where the width W 20   x  of the detection electrode  220  in the X direction is small. That is, in a case where the width W 20   x  of the detection electrode  220  in the X direction is large, the change in capacitance with respect to the change in proportion of the ink INK existing between the input electrode  210  and the detection electrode  220  becomes sensitive as compared with a case where the width W 20   x  of the detection electrode  220  in the X direction is small. In a case where the change in capacitance with respect to the change in proportion of the ink INK existing between the input electrode  210  and the detection electrode  220  is sensitive, the storage amount of the ink INK in the ink tank  100  can be detected accurately as compared with a case where the change in capacitance is not sensitive. Therefore, in the present embodiment, as explained in  FIG.  11    and the like, the detection electrodes  220   a  and  220   b  are formed such that the width W 20   x  in the X direction is larger than the width W 20   z  in the Z direction. 
     Next, an example of an operation of the control unit  4  will be explained with reference to  FIG.  14   . 
       FIG.  14    is a flowchart showing an example of the operation of the control unit  4 . Note that  FIG.  14    shows an example of the operation of the control unit  4  when the control unit  4  specifies the storage amount of the ink INK in the ink tank  100 . 
     First, in step S 100 , the control unit  4  starts outputting the input signal Vin to the input electrode  210  and the SH circuit  25  by controlling the AC power supply ACP. For example, the control unit  4  outputs a control signal for instructing the AC power supply ACP to start outputting the input signal Vin including a pulse having an amplitude of 3.3 [V]. As a result, the AC power supply ACP outputs the input signal Vin to the input electrode  210  and the SH circuit  25 . 
     Next, in step S 200 , the control unit  4  causes the selection circuit  21  to select the detection electrode  220   a  at the position H 1  lower than the detection electrode  220   b  from the detection electrodes  220   a  and  220   b . As a result, a digital signal indicating the magnitude of the detection signal Vout 1  input to the detection circuit  20  from the detection electrode  220   a  selected by the selection circuit  21  is output from the detection circuit  20  to the control unit  4  as the output signal Do. 
     Next, in step S 300 , the control unit  4  determines whether or not a value of the output signal Do is less than a determination threshold value. The determination threshold value is, for example, a threshold value corresponding to the voltage Vth shown in  FIG.  9   . For example, the determination threshold value is a threshold value for determining whether or not the liquid level L of the ink INK in the ink tank  100  is lower than a position corresponding to the detection electrode  220 . 
     If a result of the determination in step S 300  is affirmative, the control unit  4  advances the process to step S 400 . On the other hand, if the result of the determination in step S 300  is negative, the control unit  4  advances the process to step S 420 . 
     In step S 400 , the control unit  4  specifies that the liquid level L of the ink INK in the ink tank  100  exists at the position lower than the position of the detection electrode  220  selected by the selection circuit  21 . After executing the process of step S 400 , the control unit  4  advances the process to step S 700 . 
     Further, in step S 420 , the control unit  4  specifies that the liquid level L of the ink INK in the ink tank  100  exists at a height equal to or higher than the position of the detection electrode  220  selected by the selection circuit  21 . After executing the process of step S 420 , the control unit  4  advances the process to step S 500 . 
     In step S 500 , the control unit  4  determines whether or not the detection electrode  220   b  at the position H 2  higher than the detection electrode  220   a  has been selected from the detection electrodes  220   a  and  220   b . If a result of the determination in step S 500  is affirmative, the control unit  4  advances the process to step S 700 . On the other hand, if the result of the determination in step S 500  is negative, the control unit  4  advances the process to step S 600 . 
     In step S 600 , the control unit  4  causes the selection circuit  21  to select the detection electrode  220   b  at the position H 2  higher than the detection electrode  220   a  from the detection electrodes  220   a  and  220   b . As a result, a digital signal indicating the magnitude of the detection signal Vout 2  input to the detection circuit  20  from the detection electrode  220   b  selected by the selection circuit  21  is output from the detection circuit  20  to the control unit  4  as the output signal Do. After executing the process of step S 600 , the control unit  4  returns the process to step S 300 . As a result, the determination is executed as to whether or not the liquid level L of the ink INK in the ink tank  100  is lower than the position corresponding to the detection electrode  220   b.    
     Further, in step S 700 , the control unit  4  stops outputting the input signal Vin to the input electrode  210  and the SH circuit  25  by controlling the AC power supply ACP. For example, the control unit  4  outputs a control signal for instructing the AC power supply ACP to stop outputting the input signal Vin. As a result, the AC power supply ACP stops outputting the input signal Vin. After executing the process of step S 700 , the control unit  4  ends the process of specifying the storage amount of the ink INK in the ink tank  100 . 
     The operation of the control unit  4  is not limited to the example shown in  FIG.  14   . For example, the control unit  4  may advance the process to step S 500  after executing the process of step S 400 . That is, even when the control unit  4  specifies that the liquid level L of the ink INK is at the position lower than the position corresponding to the detection electrode  220   a , the control unit  4  may select the detection electrode  220   b  at the position H 2  higher than the detection electrode  220   a  to execute the determination of step S 300 . Then, for example, when a determination result of step S 300  when the detection electrode  220   b  is selected contradicts a determination result of step S 300  when the detection electrode  220   a  is selected, the control unit  4  may determine that there is a measurement error. 
     For example, when the value of the output signal Do indicating the magnitude of the detection signal Vout 1  of the detection electrode  220   a  is less than the determination threshold value, the liquid level L of the ink INK is a position lower than the position corresponding to the detection electrode  220   a . Therefore, the liquid level L of the ink INK is a position lower than the position corresponding to the detection electrode  220   b  at the position H 2  higher than the detection electrode  220   a . Therefore, when a measurement error does not occur, the value of the output signal Do indicating the magnitude of the detection signal Vout 2  of the detection electrode  220   b  is less than the determination threshold value. Therefore, when the value of the output signal Do indicating the magnitude of the detection signal Vout 1  of the detection electrode  220   a  is less than the determination threshold value and the value of the output signal Do indicating the magnitude of the detection signal Vout 2  of the detection electrode  220   b  is equal to or greater than the determination threshold value, the control unit  4  may determine that there is a measurement error. 
     Further, the control unit  4  may select the detection electrode  220   b  in step S 200  and select the detection electrode  220   a  in step S 600 . In this case, the determination of step S 500  is omitted, and the determination as to whether or not the detection electrode  220   a  has been selected is executed after at least step S 400  out of steps S 400  and  420 . 
     Further, the control unit  4  may determine in step S 300  whether or not the value of the output signal Do is equal to or greater than the determination threshold value. 
     Next, an example of a method for manufacturing the tank unit  10  will be explained with reference to  FIG.  15   . 
       FIG.  15    is an explanatory diagram for explaining an example of a method for manufacturing the tank unit  10 . 
     First, in process P 100 , the first adhesive layer  262  of the double-sided tape  260  and the FPC  200  are adhered to each other. 
     Next, in process P 200 , the position of the FPC  200  with respect to the ink tank  100  is determined by fitting between the positioning portion PT 10  and the positioning portion PT 20  and fitting between the positioning portion PT 12  and the positioning portion PT 22 . That is, the position of the FPC  200  with respect to the ink tank  100  is determined by fitting the positioning portion PT 10  provided in the outer wall  120   d  with the positioning portion PT 20  provided in the FPC  200 . 
     Next, in an FPC adhering process of process P 300 , the second adhesive layer  266  of the double-sided tape  260  adhered to the FPC  200  is adhered to the ink tank  100 . 
     More specifically, first, in process P 320 , the FPC  200  is adhered to the second arrangement portion PP 2  of the ink tank  100 . In the present embodiment, the second arrangement portion PP 2  corresponds to a portion of the plurality of outer walls  120  having a higher elastic modulus than the first arrangement portion PP 1 . That is, in process P 320 , the portion of the plurality of outer walls  120  having a higher elastic modulus than the first arrangement portion PP 1  is adhered to the second adhesive layer  266  of the double-sided tape  260  adhered to the FPC  200 . Therefore, process P 320  includes a process of adhering the second adhesive layer  266  of the double-sided tape  260  adhered to the FPC  200  and the outer wall  120   d . Then, in process P 340 , the FPC  200  is adhered to the first arrangement portion PP 1  of the ink tank  100 . More specifically, the first arrangement portion PP 1  and the second adhesive layer  266  of the double-sided tape  260  adhered to the FPC  200  are adhered to each other. Therefore, process P 340  includes a process of adhering the second adhesive layer  266  of the double-sided tape  260  adhered to the FPC  200  to the outer wall  120   a . As described above, in the present embodiment, process P 300  includes processes P 320  and P 340 . 
     The ink tank  100  is formed by fixing the outer wall  120   a  formed of a nylon film to a portion formed of a plastic or the like having a higher elastic modulus than the nylon film, for example, the outer walls  120   c ,  120   d  and  120   e , and the like. The process of fixing the outer wall  120   a  to the outer walls  120   c ,  120   d  and  120   e  and the like may be executed before process P 100  or after process P 100  as long as it is executed before process P 200 . 
     For example, in the manufacturing method of a comparative example in which the FPC  200  is adhered to the outer wall  120   a  and then the outer wall  120   a  is adhered to the outer walls  120   c ,  120   d  and  120   e , and the like, there is a risk that the FPC  200  will be damaged by a pressing process by a roller for crimping, and the like. On the other hand, in the present embodiment, since the FPC  200  is adhered to the outer wall  120   a  after the process of adhering the outer wall  120   a  to the outer walls  120   c ,  120   d  and  120   e , and the like, it is possible to suppress the damage to the FPC  200 . 
     Further, in the manufacturing method of another comparative example in which the double-sided tape  260  is adhered to the ink tank  100  and then the double-sided tape  260  and the FPC  200  are adhered, the FPC  200  is adhered to the double-sided tape  260  adhered to the ink tank  100 . Therefore, in the manufacturing method of the other comparative example described above, it is difficult to accurately adhere the FPC  200  to the double-sided tape  260  as compared with the present embodiment, so that the attachment position of the FPC  200  may deviate from a predetermined position. If the attachment position of the FPC  200  deviates from the predetermined position, the FPC  200  may float from the ink tank  100 . 
     In the present embodiment, since process P 300  of adhering the double-sided tape  260  and the ink tank  100  is executed after process P 100  of adhering the FPC  200  and the double-sided tape  260 , the FPC  200  can be accurately adhered to the double-sided tape  260 . Therefore, in the present embodiment, by executing process P 300  after process P 100 , the tank unit  10  can be easily manufactured while suppressing the deviation of the attachment position of the FPC  200  with respect to the ink tank  100  from the predetermined position. 
     Next, with reference to  FIG.  16   , an example of detecting the storage amount of the ink INK when the ink tank  100  is inclined will be explained. 
       FIG.  16    is an explanatory diagram for explaining an example of detecting the storage amount of the ink INK when the ink tank  100  is inclined.  FIG.  16    is a schematic view of the ink tank  100  seen from the +Y direction. In  FIG.  16   , the ink tank  100  in a case where the edge portion EP 1  of the outer wall  120   e  is located in the +Z direction with respect to the edge portion EP 2  of the outer wall  120   e  is schematically shown. For example, in  FIG.  16   , in order to make the figure easier to see, the illustration of elements other than the detection electrodes  220   a  and  220   b  among a plurality of elements included in the FPC  200  is omitted. 
     In the example shown in  FIG.  16   , the liquid level L of the ink INK indicated by the two-dot chain line is located in the +Z direction with respect to the discharge port Hd. In this case, since the ink INK exists between the input electrode  210  and the detection electrode  220   a , the detection signal Vout 1  having a magnitude corresponding to a proportion of the ink INK existing between the input electrode  210  and the detection electrode  220   a  is input to the detection circuit  20 . 
     For example, when the width W 20   ax  of the detection electrode  220   a  is a width exW smaller than the width WHx of the discharge port Hd, there is no ink INK between the input electrode  210  and the detection electrode  220   a  having the width exW. In this case, even if the ink INK that can be used for the printing process remains in the ink tank  100 , it is erroneously determined that the storage amount of the ink INK is less than a predetermined lower limit value. The ink INK that can be used for the printing process is, for example, the ink INK that can be discharged from the discharge port Hd when the printing process is executed. In the present embodiment, since the width W 20   ax  of the detection electrode  220   a  is larger than the width WHx of the discharge port Hd, it is possible to suppress erroneous determination that the storage amount of the ink INK is less than the lower limit value. 
     The liquid level L of the ink INK shown by the dotted line in  FIG.  16    corresponds to the liquid level L of the ink INK remaining in the space SP without being discharged from the discharge port Hd because the ink tank  100  is inclined. In this case, since the ink INK does not exist between the input electrode  210  and the detection electrode  220   a , it is determined that the storage amount of the ink INK is less than the lower limit value. As described above, in the present embodiment, since the detection electrode  220   a  is formed near the discharge port Hd, it is possible to suppress the erroneous detection of the ink INK that remains in the space SP without being discharged from the discharge port Hd, as the ink INK that can be used for the printing process. For example, in the aspect of the first comparative example described later in  FIG.  17   , since the detection electrode  220   a  is formed at a place far from the discharge port Hd, the ink INK remaining in the space SP without being discharged from the discharge port Hd may be erroneously detected as the ink INK that can be used for the printing process. 
     Next, with reference to  FIG.  17   , the outline of the ink tank  100 Z according to the first comparative example in which the detection electrode  220   a  is formed at a place far from the discharge port Hd will be explained. 
       FIG.  17    is an explanatory diagram for explaining the outline of the ink tank  100 Z according to the first comparative example.  FIG.  17    is a schematic view of the ink tank  100 Z seen from the +Y direction. In  FIG.  17   , similarly to  FIG.  16   , the ink tank  100 Z in a case where the edge portion EP 1  of the outer wall  120   e  is located in the +Z direction with respect to the edge portion EP 2  of the outer wall  120   e  is schematically shown. In the ink tank  100 Z according to the first comparative example, the discharge port Hd is provided near the edge portion EP 1  of the outer wall  120   e , and the detection electrodes  220   a  and  220   b  and the input electrode  210  (not shown in  FIG.  17   ) are provided at a position closer to the edge portion EP 1  of the outer wall  120   e  than the discharge port Hd. Other configurations of the ink tank  100 Z are the same as the configurations of the ink tank  100  explained with reference to  FIGS.  1  to  16   . 
     The liquid level L of the ink INK shown by the dotted line in  FIG.  17    corresponds to the liquid level L of the ink INK remaining in the space SP without being discharged from the discharge port Hd because the ink tank  100 Z is inclined. In the example shown in  FIG.  17   , since the ink INK exists between the input electrode  210  and the detection electrode  220   a , the detection signal Vout 1  having a magnitude corresponding to a proportion of the ink INK existing between the input electrode  210  and the detection electrode  220   a  is input to the detection circuit  20 . Therefore, in the first comparative example, there is a possibility that the ink INK remaining in the space SP without being discharged from the discharge port Hd is erroneously detected as the ink INK that can be used for the printing process. On the other hand, in the present embodiment, as explained in  FIG.  16   , since the detection electrode  220   a  is formed near the discharge port Hd, even when the ink tank  100  is inclined, it is possible to suppress the erroneous detection of the storage amount of the ink INK. 
     Further, in the first comparative example, in a case where the ink tank  100 Z is inclined such that the edge portion EP 1  near the discharge port Hd is located in the +Z direction with respect to the edge portion EP 2  far from the discharge port Hd, the amount of the ink INK remaining in the space SP without being discharged from the discharge port Hd increases as compared with the present embodiment. That is, in the present embodiment, since the discharge port Hd is provided near the center of the outer wall  120   e , when the ink tank  100  is used in an inclined state, it is possible to reduce the amount of the ink INK remaining in the space SP without being discharged from the discharge port Hd. 
     As described above, in the present embodiment, the ink jet printer  1  includes the tank unit  10  for storing ink INK, the detection circuit  20  for detecting the storage amount of the ink INK stored in the tank unit  10 , and the ejection section  30   a  for ejecting the ink INK supplied from the tank unit  10 . 
     The tank unit  10  includes the ink tank  100  and the FPC  200  fixed to the ink tank  100 . The ink tank  100  includes the plurality of outer walls  120  and the plurality of partition walls  122 , and stores the ink INK in the space SP surrounded by the plurality of outer walls  120   a ,  120   b ,  120   c ,  120   d  and  120   e  and the plurality of partition walls  122   a  and  122   b . Further, the ink tank  100  includes the positioning portion PT 10 . 
     The FPC  200  includes the input electrode  210  provided in the outer wall  120   a , the detection electrode  220   a  provided in the outer wall  120   b , the wiring  212  coupled to the input electrode  210 , and the wiring  222   a  coupled to the detection electrode  220   a . Further, the FPC  200  includes the positioning portion PT 20  that is coupled to the positioning portion PT 10  to determine a position of the FPC  200 . 
     In the present embodiment, the outer wall  120   a  is an example of a “first wall”, the outer wall  120   b  is an example of a “second wall”, and the outer wall  120   d  is an example of a “third wall”. Further, the input electrode  210  is an example of a “first electrode”, and the detection electrode  220   a  is an example of a “second electrode”. The wiring  212  is an example of a “first wiring”, and the wiring  222   a  is an example of a “second wiring”. The positioning portion PT 10  is an example of a “first positioning portion”, and the positioning portion PT 20  is an example of a “second positioning portion”. Further, the positioning portion PT 12  is an example of a “third positioning portion”, and the positioning portion PT 22  is an example of a “fourth positioning portion”. The terminal TMt 1  is an example of a “first terminal”, the terminal TMr 1  is an example of a “second terminal”, and the terminal TMg is an example of a “constant voltage terminal”. The external contact CTt 1  is an example of a “first external contact”, and the external contact CTr 1  is an example of a “second external contact”. The Z direction is an example of a “first direction”. 
     Further, in a modification example described later, a positioning portion PT 22 A is an example of a “fourth positioning portion”, and a positioning portion PT 22 B is an example of a “sixth positioning portion”. Further, a positioning portion PT 24  is an example of a “second end positioning portion”, and a positioning portion PT 26  is an example of a “fourth end positioning portion”. Further, among a plurality of the positioning portions PT provided in the ink tank  100 , the positioning portion PT corresponding to the positioning portion PT 22 A is an example of the “third positioning portion”, and the positioning portion PT corresponding to the positioning portion PT 22 B is an example of the “fifth positioning portion”. The positioning portion PT corresponding to the positioning portion PT 24  is an example of a “first end positioning portion”, and the positioning portion PT corresponding to the positioning portion PT 26  is an example of a “third end positioning portion”. 
     As described above, in the present embodiment, when the FPC  200  is attached to the ink tank  100 , the positioning portion PT 20  of the FPC  200  is coupled to the positioning portion PT 10  of the ink tank  100 . Thereby, in the present embodiment, it is possible to suppress the deviation of the position of the FPC  200  with respect to the ink tank  100  from a predetermined position when the FPC  200  is attached to the ink tank  100 . That is, in the present embodiment, it is possible to suppress the deviation of the input electrode  210  and the detection electrode  220   a  from the predetermined position. Thereby, in the present embodiment, the change in the capacitance CC between the input electrode  210  and the detection electrode  220   a  can be detected with high accuracy. As a result, in the present embodiment, it is possible to improve the detection accuracy of the storage amount of the ink INK in the ink tank  100 . 
     Further, in the present embodiment, the positioning portion PT 20  is fitted with the positioning portion PT 10 . The positioning portion PT 20  is located between the input electrode  210  and the detection electrode  220   a  in the FPC  200 . As described above, in the present embodiment, since the positioning portion PT 20  is located between the input electrode  210  and the detection electrode  220   a  in the FPC  200 , it is possible to suppress significant deviation of one of the input electrode  210  and the detection electrode  220   a  from the predetermined position. As a result, in the present embodiment, it is possible to improve the detection accuracy of the storage amount of the ink INK in the ink tank  100 . Further, in the present embodiment, since the positioning portion PT 20  is fitted with the positioning portion PT 10 , the work of determining the position of the FPC  200  with respect to the ink tank  100  can be facilitated. 
     Further, in the present embodiment, the ink tank  100  further includes the positioning portion PT 12 , and the FPC  200  further includes the positioning portion PT 22  that is fitted with the positioning portion PT 12 . As described above, in the present embodiment, the position of the FPC  200  with respect to the ink tank  100  is determined at two locations of the positioning portions PT 10  and PT 20  that are fitted to each other and the positioning portions PT 12  and PT 22  that are fitted to each other. Thereby, in the present embodiment, for example, it is possible to suppress the rotation of the FPC  200  and the like when the FPC  200  is attached to the ink tank  100 . Therefore, in the present embodiment, the work of attaching the FPC  200  to the ink tank  100  can be facilitated. 
     Further, in the present embodiment, one or both of the shape and the size are different between the positioning portion PT 10  and the positioning portion PT 12 . Thereby, in the present embodiment, it is possible to reduce that the positioning portion PT 22  is erroneously fitted with the positioning portion PT 10  or the positioning portion PT 20  is erroneously fitted with the positioning portion PT 12 . Thereby, in the present embodiment, it is possible to reduce that the FPC  200  is attached to the ink tank  100  in the wrong orientation. 
     Further, in the present embodiment, the positioning portion PT 10  is provided in the outer wall  120   d , and the shape of the positioning portion PT 10  is a protruding shape. Further, the outer wall  120   d  and the positioning portion PT 10  are formed of a plastic. In the present embodiment, since the positioning portion PT 10  provided in the outer wall  120   d  is formed in a protruding shape, the positioning portions PT 10  and PT 20  can be easily formed as compared with a case where the positioning portion PT 20  provided in the FPC  200  is formed in a protruding shape. 
     Further, in the present embodiment, the positioning portions PT 10  and PT 12  are provided in the outer wall  120   d . The FPC  200  includes the terminal TMt 1  electrically coupled to the input electrode  210  and in contact with the external contact CTt 1  externally provided, the terminal TMr 1  electrically coupled to the detection electrode  220   a  and in contact with the external contact CTr 1  externally provided, and the terminal TMg held at a constant voltage. In the FPC  200 , at least a part of the terminal arrangement region AR including the terminals TMt 1 , TMr 1  and TMg is located between the positioning portion PT 20  and the positioning portion PT 22 . 
     As described above, in the present embodiment, since the plurality of terminals TM are arranged near the positioning portions PT 20  and PT 22 , it is possible to reduce the deviation of the plurality of terminals TM with respect to the ink tank  100  from a predetermined position. As a result, in the present embodiment, the erroneous coupling between the plurality of terminals TM and the plurality of external contacts CT can be suppressed. Further, in the present embodiment, since it is possible to reduce the deviation of the plurality of terminals TM with respect to the ink tank  100  from the predetermined position, it is possible to improve stability of the coupling between the plurality of terminals TM and the plurality of external contacts CT. 
     Further, in the present embodiment, in the FPC  200 , the distance D 12  between the input electrode  210  and the detection electrode  220   a  is larger than the width W 10   z  of the input electrode  210  in the Z direction intersecting the extending direction of the FPC  200 . In an aspect in which the distance D 12  between the input electrode  210  and the detection electrode  220   a  is small, when the position of the FPC  200  is deviated, an amount of deviation of the detection electrode  220   a  or the like with respect to a predetermined position tends to be large as compared with an aspect in which the distance D 12  between the input electrode  210  and the detection electrode  220   a  is large. Therefore, in the present embodiment, it is possible to reduce the deviation of the positions of the input electrode  210  and the detection electrode  220   a  with respect to the ink tank  100  from the predetermined position as compared with an aspect in which the distance D 12  between the input electrode  210  and the detection electrode  220   a  is small. 
     2. Modification Example 
     Each of the above examples can be modified in various ways. Specific aspects of modification are illustrated below. Two or more aspects optionally selected from the following examples can be appropriately combined as long as they do not conflict with each other. In the modification examples exemplified below, for elements whose actions and functions are equivalent to those of the embodiment, the reference numerals referred to in the above description will be used and detailed descriptions thereof will be omitted as appropriate. 
     First Modification Example 
     In the above-described embodiment, a case where the FPC  200  extends in the X direction with a substantially constant width is exemplified, but the present disclosure is not limited to such an aspect. For example, widths of the bent portions BP 1  and BP 2  of the FPC  200  in the Z direction may be smaller than a width of a portion of the FPC  200  other than the bent portions BP 1  and BP 2  in the Z direction. 
       FIG.  18    is a plan view showing an example of an FPC  200 A according to the first modification example. Note that  FIG.  18    shows a plan view of the FPC  200 A in a state of not being adhered to the ink tank  100 , as in  FIG.  11   . In  FIG.  18   , in order to make the figure easier to see, the FPC  200 A is described by being divided into a figure of the first cover film layer  201  and the first conductor layer  202 , and a figure of the base material layer  203 , the second conductor layer  204 , and the second cover film layer  205 . The same elements as those explained with reference to  FIGS.  1  to  17    are designated by the same reference numerals, and detailed explanations thereof will be omitted. 
     In the FPC  200 A, a width WB 1   z  of the bent portion BP 1  in the Z direction is smaller than a width WE 1   z  of a portion where the input electrode  210  is provided in the Z direction. Similarly, a width WB 2   z  of the bent portion BP 2  in the Z direction is smaller than a width WE 2   z  of the portion where the detection electrode  220  is provided in the Z direction. Therefore, in this modification example, the rigidity of the bent portions BP 1  and BP 2  of the FPC  200 A can be made lower than both the rigidity of the portion where the input electrode  210  is provided and the rigidity of the portion where the detection electrode  220  is provided. 
     Further, since the width WB 1   z  of the bent portion BP 1  and the width WB 2   z  of the bent portion BP 2  are different from those of the FPC  200 , shapes of the wirings  212 ,  222   a  and  222   b  and the like are different from those of the FPC  200 . For example, in the FPC  200 A, the lead wiring  242   c  that couples the shield wiring  240   c  and the through wiring TW 4   c  is formed of the same material as the input electrode  210 . In this modification example, it is assumed that the shield wiring  240   c  and the lead wiring  242   c  are integrally formed. Further, the FPC  200 A includes positioning portions PT 22 A and PT 22 B instead of the positioning portion PT 22 . Further, the FPC  200 A includes a positioning portion PT 24  and a PT 26 . Other configurations of the FPC  200 A are the same as those of the FPC  200 . 
     For example, the shield wiring  240   d  includes a region that overlaps the entire input electrode  210  and at least a part of the wiring  212  in a plan view from the +Y direction. Also in this modification example, for example, the width W 40   dx  of the shield wiring  240   d  in the X direction is larger than the width W 10   x  of the input electrode  210  in the X direction. Further, a width W 40   dz  of the shield wiring  240   d  in the Z direction is larger than the width W 10   z  of the input electrode  210  in the Z direction. In the FPC  200 A, the two edge portions EP 3   d  and EP 4   d  of the shield wiring  240   d  are located in the −X direction with respect to the bent portion BP 1 . Therefore, a width W 42   dz  of the bent portion BP 1  in the Z direction of the lead wiring  242   d  of the shield wiring  240   d  is smaller than the width W 40   dz  of the shield wiring  240   d  in the Z direction. 
     Further, for example, the shield wiring  240   e  includes a region that overlaps the entire detection electrode  220   a , the entire detection electrode  220   b , at least a part of the wiring  222   a , and at least a part of the wiring  222   b  in a plan view from the +Y direction. For example, a width W 40   ex  of the shield wiring  240   e  in the X direction is larger than both the width W 20   ax  of the detection electrode  220   a  in the X direction and the width W 20   bx  of the detection electrode  220   b  in the X direction. In the FPC  200 A, the two edge portions EP 3   e  and EP 4   e  of the shield wiring  240   e  are located in the +X direction with respect to the bent portion BP 2 . Therefore, the width W 42   ez  of the bent portion BP 2  in the Z direction of the lead wiring  242   e  of the shield wiring  240   e  is smaller than the width W 40   ez  of the shield wiring  240   e  in the Z direction. 
     Further, a width W 42   cz  of the lead wiring  242   c  in the Z direction is smaller than the width W 40   cz  of the shield wiring  240   c  in the Z direction. In this modification example, it is assumed that the width W 40   cz  of the shield wiring  240   c , the width W 20   ax  of the detection electrode  220   a , and the width W 20   bx  of the detection electrode  220   b  are substantially the same. 
     Further, the positioning portions PT 20 , PT 22 A and PT 22 B are arranged such that a line connecting the positioning portions PT 20 , PT 22 A and PT 22 B is grasped as a triangular shape in a plan view from the +Y direction. For example, the positioning portion PT 22 B has a center in the FPC  200 A at a position deviated from a line passing through a center of the positioning portion PT 20  and a center of the positioning portion PT 22 A. 
     Further, in the FPC  200 A, the positioning portion PT 24  is formed on an edge portion EP 5  on which the input electrode  210  is provided, and the positioning portion PT 26  is formed on an edge portion EP 6  on which the detection electrode  220  is provided. 
     Each of the plurality of positioning portions PT 20 , PT 22 A, PT 22 B, PT 24  and PT 26  is formed by cutting out the edge portion of the FPC  200 A, for example, similarly to the positioning portion PT 20 . The plurality of positioning portions PT 20 , PT 22 A, PT 22 B, PT 24  and PT 26  are not limited to the cutouts. For example, a part or all of the plurality of positioning portions PT 20 , PT 22 A, PT 22 B, PT 24  and PT 26  may be through holes penetrating through the FPC  200 A in the X direction. 
     The ink tank  100  to which the FPC  200 A is attached is provided with the plurality of positioning portions PT having a one-to-one correspondence with the plurality of positioning portions PT 20 , PT 22 A, PT 22 B, PT 24  and PT 26 . For example, each of the plurality of positioning portions PT provided in the ink tank  100  is formed in a protruding shape for fitting with the corresponding positioning portion PT among the plurality of positioning portions PT 20 , PT 22 A, PT 22 B, PT 24  and PT 26 . 
     The arrangement of the plurality of positioning portions PT is not limited to the example shown in  FIG.  18   . For example, in the FPC  200 A, two positioning portions PT penetrating through the FPC  200 A may be formed at positions sandwiching the terminal arrangement region AR in the X direction. 
     As described above, even in this modification example, the same effect as that of the above-described embodiment can be obtained. In this modification example, the second conductor layer  204  includes the lead wiring  242   d  coupled to the shield wiring  240   d  and the lead wiring  242   e  coupled to the shield wiring  240   e . The lead wiring  242   d  includes the bent portion BP 1  of which the width W 42   dz  in the Z direction is smaller than the width W 40   dz  of the shield wiring  240   d  in the Z direction. The lead wiring  242   e  includes the bent portion BP 2  of which the width W 42   ez  in the Z direction is smaller than the width W 40   ez  of the shield wiring  240   e  in the Z direction. The FPC  200 A is bent along the outer periphery of the ink tank  100  at the bent portions BP 1  and BP 2 . Thereby, in this modification example, the rigidity of the bent portion BP 1  can be made lower than that of a portion where the shield wiring  240   d  is arranged. Similarly, in this modification example, the rigidity of the bent portion BP 2  can be made lower than that of a portion where the shield wiring  240   e  is arranged. 
     Further, in this modification example, in the FPC  200 A, the positioning portion PT 22 B has a center at a position deviated from the line passing through the center of the positioning portion PT 20  and the center of the positioning portion PT 22 A. In this case, the positioning portions PT 20 , PT 22 A and PT 22 B are arranged such that the line connecting the positioning portions PT 20 , PT 22 A and PT 22 B is grasped as a triangular shape in a plan view from the +Y direction. Therefore, in this modification example, for example, it is possible to further reduce the deviation of the position of the FPC  200  with respect to the ink tank  100  from the predetermined position as compared with a case where the positioning portions PT are only the positioning portions PT 10  and PT 20 . 
     Further, in this modification example, the FPC  200 A includes the positioning portion PT 24 . The positioning portion PT 24  is located at the edge portion EP 5  on which the input electrode  210  is provided. The ink tank  100  includes the positioning portion PT that is fitted with the positioning portion PT 24 . In this case, it is possible to reduce the deviation of the position of the input electrode  210  with respect to the ink tank  100  from the predetermined position. 
     Further, in this modification example, the FPC  200 A includes the positioning portion PT 26 . The positioning portion PT 26  is located at the edge portion EP 6  on which the detection electrode  220  is provided. The ink tank  100  includes the positioning portion PT that is fitted with the positioning portion PT 26 . In this case, it is possible to reduce the deviation of the position of the detection electrode  220  with respect to the ink tank  100  from the predetermined position. 
     Second Modification Example 
     In the above-described embodiment and modification example, a case where the position of the wiring  222   a  overlaps the detection electrode  220   a  in the Z direction is exemplified, but the present disclosure is not limited to such an aspect. For example, a position of a part of the wiring  222   a  and the position of the detection electrode  220   a  may be different from each other in the Z direction. 
       FIG.  19    is an explanatory diagram for explaining the outline of the FPC  200 B according to the second modification example. Note that  FIG.  19    is a plan view of the ink tank  100  and the FPC  200 B as seen from the +Y direction. In  FIG.  19   , in order to make the explanation easier to understand, the illustration of the shield wiring  240   e  and the like is omitted. The same elements as those explained in  FIGS.  1  to  18    are designated by the same reference numerals, and detailed explanations thereof will be omitted. 
     The FPC  200 B is the same as the FPC  200 A shown in  FIG.  18    except that the wirings  222   a ,  222   b  and the like are formed so as to extend in the X direction through the position in the −Z direction with respect to the detection electrode  220   a . For example, the wiring  222   a  includes an extending portion ET 2   a  extending in the X direction, and the wiring  222   b  includes an extending portion ET 2   b  extending in the X direction. Further, the lead wiring  242   c  includes an extending portion ET 2   c  extending in the X direction. The shield wiring  240   a  includes an extending portion ET 2   d  extending in the X direction, and the shield wiring  240   b  includes an extending portion ET 2   e  extending in the X direction. In the below, the extending portions ET 2   a , ET 2   b , ET 2   c , ET 2   d  and ET 2   e  may be collectively referred to as extending portions ET 2 . 
     For example, all the extending portions ET 2  are located in the −Z direction with respect to the detection electrode  220   a . In the example shown in  FIG.  19   , the extending portion ET 2   a  of the wiring  222   a  is located closer to the discharge port Hd than the detection electrode  220   a  in the Z direction. Similarly, the extending portion ET 2   b  of the wiring  222   b  is located closer to the discharge port Hd than the detection electrode  220   b  in the Z direction. 
     For example, when the liquid level L of the ink INK changes from a position within a range of the wiring  222   a  in the Z direction to a position in the −Z direction with respect to the wiring  222   a  or a position in the +Z direction with respect to the wiring  222   a , the wiring  222   a  may detect a change in the remaining amount of the ink INK. 
     When the range of the wiring  222   a  in the Z direction overlaps a range of the detection electrode  220   a  in the Z direction, the timing at which the detection electrode  220   a  detects the change in the remaining amount of the ink INK may overlap a timing at which the wiring  222   a  detects the change in the remaining amount of the ink INK. In this case, an error corresponding to a detection result by the wiring  222   a  may be included in a detection result by the detection electrode  220   a . Therefore, for example, it is preferable that the wiring  222   a  is routed mainly through the position in the −Z direction with respect to the detection electrode  220   a  or the position in the +Z direction with respect to the detection electrode  220   a.    
     In this modification example, since the wirings  222   a ,  222   b  and the like are routed through the position in the −Z direction with respect to the detection electrode  220   a , the detection accuracy of the storage amount of the ink INK can be improved as compared with a case where the range of the wiring  222   a  in the Z direction overlaps the range of the detection electrode  220   a  in the Z direction. 
     Next, the overall configuration of the FPC  200 B will be explained with reference to  FIG.  20   . 
       FIG.  20    is a plan view showing an example of the FPC  200 B shown in  FIG.  19   . Note that  FIG.  20    shows a plan view of the FPC  200 B in a state of not being adhered to the ink tank  100 , as in  FIG.  18   . Further, in  FIG.  20   , the FPC  200 B is described by being divided into a figure of the first cover film layer  201  and the first conductor layer  202 , and a figure of the base material layer  203 , the second conductor layer  204 , and the second cover film layer  205 , as in  FIG.  18   . The same elements as those explained with reference to  FIGS.  1  to  19    are designated by the same reference numerals, and detailed explanations thereof will be omitted. 
     In the FPC  200 B, the wirings  212 ,  222   a  and  222   b  and the shield wirings  240   a  and  240   b  are routed through the positions in the −Z direction with respect to both the input electrode  210  and the detection electrode  220   a.    
     For example, the wiring  212  includes an extending portion ET 1   a  extending in the X direction. Further, the shield wiring  240   a  includes an extending portion ET 1   d  extending in the X direction, and the shield wiring  240   b  includes an extending portion ET 1   e  extending in the X direction. Hereinafter, the extending portions ET 1   a , ET 1   d  and ET 1   e  may be collectively referred to as extending portions ET 1 . 
     For example, the extending portion ET 1  of each of the wiring  212  and the shield wirings  240   a  and  240   b  extends in the X direction through the bent portion BP 1 . Similarly, for example, the extending portion ET 2  of each of the wirings  222   a  and  222   b  and the shield wirings  240   a ,  240   b  and  240   c  extends in the X direction through the bent portion BP 2 . 
     Further, the extending portion ET 1  of each of the wiring  212  and the shield wirings  240   a  and  240   b  are located in the −Z direction with respect to the input electrode  210 . For example, the extending portion Ella of the wiring  212  is located closer to the discharge port Hd than the input electrode  210  in the Z direction, similarly to the extending portion ET 2   a  of the wiring  222   a  explained in  FIG.  19   . 
     Further, for example, the lead wiring  242   d  of the shield wiring  240   d  is formed in a shape including a region overlapping the extending portion ET 1  of each of the wiring  212  and the shield wirings  240   a  and  240   b  in a plan view from the +Y direction. Similarly, the lead wiring  242   e  of the shield wiring  240   e  is formed in a shape including a region overlapping the extending portion ET 2  of each of the wirings  222   a  and  222   b  and the shield wirings  240   a  and  240   b  in a plan view from the +Y direction. 
     Also in the FPC  200 B, the width WB 1   z  of the bent portion BP 1  in the Z direction is smaller than the width WE 1   z  of the portion where the input electrode  210  is provided in the Z direction, and the width WB 2   z  of the bent portion BP 2  in the Z direction is smaller than the width WE 2   z  of the portion where the detection electrode  220  is provided in the Z direction. Therefore, also in this modification example, the rigidity of the bent portions BP 1  and BP 2  of the FPC  200 A can be made lower than both the rigidity of the portion where the input electrode  210  is provided and the rigidity of the portion where the detection electrode  220  is provided. 
     The configuration of the FPC  200 B according to the second modification example is not limited to the examples shown in  FIGS.  19  and  20   . For example, the extending portion ET 1  of each of the wiring  212  and the shield wirings  240   a  and  240   b  may be located in the +Z direction with respect to the input electrode  210 . Similarly, the extending portion ET 2  of each of the wirings  222   a  and  222   b  and the shield wirings  240   a  and  240   b  may be located in the +Z direction with respect to the detection electrode  220   b . Also in this case, for example, in the wiring  222   a , the portion where the position in the Z direction overlaps the detection electrode  220   a  can be reduced, so that the detection accuracy of the storage amount of the ink INK can be improved. 
     As described above, also in this modification example, the same effect as that of the above-described embodiment and modification example can be obtained. Further, in this modification example, the wiring  212  includes the extending portion Ella extending in the X direction. Further, the wiring  222   a  includes the extending portion ET 2   a  extending in the X direction, and the wiring  222   b  includes the extending portion ET 2   b  extending in the X direction. The position of the extending portion Ella of the wiring  212  in the Z direction and the position of the input electrode  210  in the Z direction are different from each other. The position of the extending portion ET 2   a  of the wiring  222   a  in the Z direction and the position of the detection electrode  220   a  in the Z direction are different from each other, and the position of the extending portion ET 2   b  of the wiring  222   b  in the Z direction and the position of the detection electrode  220   b  in the Z direction are different from each other. 
     For example, in this modification example, the extending portion Ella of the wiring  212  is located in the −Z direction with respect to the input electrode  210 , and the extending portion ET 2   a  of the wiring  222   a  is located in the −Z direction with respect to the detection electrode  220   a . Further, the extending portion ET 2   b  of the wiring  222   b  is located in the −Z direction with respect to the detection electrode  220   b.    
     Further, in this modification example, the extending portion Ella of the wiring  212  is located closer to the discharge port Hd than the input electrode  210  in the Z direction. The extending portion ET 2   a  of the wiring  222   a  is located closer to the discharge port Hd than the detection electrode  220   b  in the Z direction. 
     As described above, in this modification example, the wirings  212 ,  222   a  and  222   b  and the shield wirings  240   a  and  240   b  are routed through the positions in the −Z direction with respect to both the input electrode  210  and the detection electrode  220   a . Therefore, in this modification example, for example, the detection accuracy of the storage amount of the ink INK can be improved as compared with a case where the range of the wiring  222   a  in the Z direction overlaps the range of the detection electrode  220   a  in the Z direction. 
     Third Modification Example 
     In the above-described embodiment and modification examples, a case where the entire outer wall  120   a  is formed of a nylon film has been exemplified, but the present disclosure is not limited to such an aspect. For example, a portion of the outer wall  120   a  other than the first arrangement portion PP 1  may be formed of a plastic having a higher elastic modulus than the nylon film. 
       FIG.  21    is a cross-sectional view showing an example of a cross section of the ink tank  100 A and the FPC  200  according to the third modification example. The cross section of the ink tanks  100 A and FPC  200  shown in  FIG.  21    corresponds to the cross section taken along the line A 1 -A 2  shown in  FIG.  3   . In  FIG.  21   , elements located in the +Z direction with respect to the partition wall  122   b , the support portion  130  and the like are not shown, as in  FIG.  7   . The same elements as those explained in  FIGS.  1  to  20    are designated by the same reference numerals, and detailed explanations thereof will be omitted. 
     The ink tank  100 A is the same as the ink tank  100  shown in  FIG.  7    except that the ink tank  100 A includes an outer wall  120 Aa instead of the outer wall  120   a  shown in  FIG.  7   . The outer wall  120 Aa includes a film portion FL formed of a film such as a nylon film and a plastic portion PL formed of a plastic having an elastic modulus larger than that of the film portion FL. For example, the material of the plastic portion PL is, for example, the same as the material of the outer wall  120   b.    
     Further, the film portion FL is the same as the outer wall  120   a  shown in  FIG.  7   . However, the film portion FL is adhered to the plastic portion PL. The plastic portion PL is adhered to the outer walls  120   c ,  120   d  and  120   e  and the like in the same manner as the outer wall  120   a  shown in  FIG.  7   . That is, the plastic portion PL is located inside the film portion FL. Further, in the plastic portion PL, a through hole Hpp 1  penetrating through the plastic portion PL is formed in the first arrangement portion PP 1 . When the outer wall  120 Aa is seen from the −Y direction, a shape of a peripheral edge portion of the through hole Hpp 1  is grasped as a shape similar to that of the first arrangement portion PP 1 , for example, a rectangular shape. Therefore, a thickness T 1  of the film portion FL is the thickness of the first arrangement portion PP 1  where the input electrode  210  or the like is provided. The thickness T 1  of the film portion FL is thinner than, for example, the thickness T 2  of the outer wall  120   b  formed of a plastic or the thickness T 3  of the outer wall  120   d  shown in  FIG.  5   . 
     The configuration of the ink tank  100 A is not limited to the example shown in  FIG.  21   . For example, the film portion FL may be formed in a size including the first arrangement portion PP 1  and a peripheral portion of the first arrangement portion PP 1  as long as the strength of adhesion to the plastic portion PL can be ensured. Further, an inner peripheral surface of the through hole Hpp 1  may be subject to the water-repellent treatment. Further, in the inner peripheral surface of the through hole Hpp 1 , the inner peripheral surface close to the outer wall  120   e  may be inclined such that an opening in the +Y direction is larger than an opening in the −Y direction. In this case, it is possible to suppress that the ink INK remains in the through hole Hpp 1 . 
     Further, for example, the outer wall  120   b  may include the film portion FL and the plastic portion PL in the same manner as the outer wall  120 Aa or the outer wall  120 Ba shown in  FIG.  22    described later. In this case, in the plastic portion PL formed as a part of the outer wall  120   b , a through hole penetrating through the plastic portion PL is formed in the second arrangement portion PP 2 . In this case, the influence of the capacitance C 5  of the second arrangement portion PP 2  on the capacitance CC between the input electrode  210  and the detection electrode  220   a  can be reduced. 
     As described above, also in this modification example, the same effect as that of the above-described embodiment and modification example can be obtained. Further, in this modification example, the first arrangement portion PP 1  of the outer wall  120 Aa is thinner than a portion of the outer wall  120 Aa other than the first arrangement portion PP 1 . In other words, the portion of the outer wall  120 Aa other than the first arrangement portion PP 1  is thicker than the first arrangement portion PP 1 . Therefore, in this modification example, for example, it is possible to suppress the deformation of the outer wall  120 Aa due to the pressure inside the ink tank  100  and the like, as compared with an aspect in which the entire outer wall  120   a  is as thin as the first arrangement portion PP 1 . That is, in this modification example, it is possible to manufacture an ink tank  100  that is not easily deformed. 
     Further, in this modification example, the second arrangement portion PP 2  may be thinner than at least a part of the plurality of outer walls  120  other than the first arrangement portion PP 1 . That is, the outer wall  120   b  may include the second arrangement portion PP 2  as a third portion thinner than at least a part of the plurality of outer walls  120  other than the first arrangement portion PP 1 . The detection electrode  220   a  is provided in the second arrangement portion PP 2 . In this case, the first arrangement portion PP 1  of the outer wall  120 Aa is thinner than a portion of the plurality of outer walls  120  other than the first arrangement portion PP 1  and the second arrangement portion PP 2 . 
     When the first arrangement portion PP 1  and the second arrangement portion PP 2  are thinner than other portions among the plurality of outer walls  120 , the influence of the capacitance C 1  of the first arrangement portion PP 1  and the capacitance C 5  of the second arrangement portion PP 2  on the capacitance CC between the input electrode  210  and the detection electrode  220   a  becomes small. Therefore, among the plurality of outer walls  120 , when the first arrangement portion PP 1  and the second arrangement portion PP 2  are thinner than other portions, it is possible to improve the detection accuracy of the storage amount of the ink INK as compared with a case where the second arrangement portion PP 2  is not thinner than the other portions. 
     Fourth Modification Example 
     In the above-described third modification example, a case where the plastic portion PL is located inside among the film portion FL and the plastic portion PL included in the outer wall  120 Aa is exemplified, but the present disclosure is not limited to such an aspect. For example, the film portion FL may be located inside among the film portion FL and the plastic portion PL included in the outer wall  120 Aa. 
       FIG.  22    is a cross-sectional view showing an example of a cross section of the ink tank  100 B and the FPC  200  according to the fourth modification example. The cross section of the ink tank  100 B and FPC  200  shown in  FIG.  22    corresponds to the cross section taken along the line A 1 -A 2  shown in  FIG.  3   . Also in  FIG.  22   , elements located in the +Z direction with respect to the partition wall  122   b , the support portion  130  and the like are not shown, as in  FIG.  7   . The same elements as those explained in  FIGS.  1  to  21    are designated by the same reference numerals, and detailed explanations thereof will be omitted. 
     The ink tank  100 B is the same as the ink tank  100  shown in  FIG.  7    except that the ink tank  100 B includes an outer wall  120 Ba instead of the outer wall  120   a  shown in  FIG.  7   . The outer wall  120 Ba includes a film portion FL formed of a film such as a nylon film and a plastic portion PL formed of a plastic having an elastic modulus larger than that of the film portion FL. For example, the material of the plastic portion PL is, for example, the same as the material of the outer wall  120   b.    
     Further, the film portion FL is the same as the outer wall  120   a  shown in  FIG.  7   . For example, the film portion FL is adhered to the outer walls  120   c ,  120   d  and  120   e , and the like, similarly to the outer wall  120   a  shown in  FIG.  7   . However, a surface of the film portion FL opposite to the inner surface IF 1  is adhered to the plastic portion PL. That is, the film portion FL is located inside the plastic portion PL. Further, in the plastic portion PL, a through hole Hpp 1  penetrating through the plastic portion PL is formed in the first arrangement portion PP 1 . When the outer wall  120 Aa is seen from the −Y direction, a shape of a peripheral edge portion of the through hole Hpp 1  is grasped as a shape similar to that of the first arrangement portion PP 1 , for example, a rectangular shape. Therefore, a thickness T 1  of the film portion FL is the thickness of the first arrangement portion PP 1  where the input electrode  210  or the like is provided. The thickness T 1  of the film portion FL is thinner than, for example, the thickness T 2  of the outer wall  120   b  formed of a plastic or the thickness T 3  of the outer wall  120   d  shown in  FIG.  5   . 
     Further, as shown in  FIG.  23   , in the inner peripheral surface of the through hole Hpp 1 , an inner peripheral surface SLP to which the FPC  200  is adhered is inclined such that an opening in the −Y direction is larger than an opening in the +Y direction. 
       FIG.  23    is a plan view showing an example of the ink tank  100 B shown in  FIG.  22   . Note that  FIG.  22    is a plan view of the ink tank  100 B seen from the −Y direction. For example, in  FIG.  16   , the FPC  200  is not shown in order to make the figure easier to see. 
     In the inner peripheral surface of the through hole Hpp 1  that penetrates through the plastic portion PL included in the outer wall  120 Ba, the inner peripheral surface SLP to which the FPC  200  is adhered is inclined such that the opening in the −Y direction is larger than the opening in the +Y direction. A shaded portion in the figure shows the inner peripheral surface SLP that is inclined such that the opening in the −Y direction is larger than the opening in the +Y direction. In this modification example, the FPC  200  and the first arrangement portion PP 1  of the film portion FL can be easily adhered to each other as compared with a case where the inner peripheral surface SLP is substantially perpendicular to the first arrangement portion PP 1  of the film portion FL. 
     The configuration of the ink tank  100 B is not limited to the examples shown in  FIGS.  22  and  23   . For example, the film portion FL may be formed in a size including the first arrangement portion PP 1  and a peripheral portion of the first arrangement portion PP 1  as long as the strength of adhesion to the plastic portion PL can be ensured. 
     Further, for example, the outer wall  120   b  may include the film portion FL and the plastic portion PL in the same manner as the outer wall  120 Ba or the outer wall  120 Aa shown in  FIG.  21   . In this case, in the plastic portion PL formed as a part of the outer wall  120   b , a through hole penetrating through the plastic portion PL is formed in the second arrangement portion PP 2 . In this case, the influence of the capacitance C 5  of the second arrangement portion PP 2  on the capacitance CC between the input electrode  210  and the detection electrode  220   a  can be reduced. 
     As described above, also in this modification example, the same effect as that of the above-described embodiment and modification example can be obtained. 
     Fifth Modification Example 
     In the above-described embodiment and modification examples, a case where the number of the detection electrodes  220  is two is exemplified, but the present disclosure is not limited to such an aspect. For example, the number of the detection electrodes  220  may be one or three or more. 
       FIG.  24    is an explanatory diagram for explaining the outline of an ink tank  100 C and an FPC  200 C according to the fifth modification example. Note that  FIG.  24    is a plan view of the ink tank  100  and the FPC  200  as seen from the +Y direction. In  FIG.  24   , the shield wiring  240   e  and the like are not shown in order to make the explanation easier to understand. The same elements as those explained in  FIGS.  1  to  18    are designated by the same reference numerals, and detailed explanations thereof will be omitted. 
     The tank unit  10  is the same as the tank unit  10  shown in  FIG.  3    except that the tank unit  10  includes the ink tank  100 C and the FPC  200 C instead of the ink tank  100  and the FPC  200  shown in  FIG.  3   . The ink tank  100 C is the same as the ink tank  100  shown in  FIG.  3    except that the FPC  200 C is attached instead of the FPC  200  and that the ink tank  100 C includes a positioning portion PT 18  and a positioning portion PT 19 . 
     For example, the outer wall  120   b  of the ink tank  100 C is provided with a positioning portion PT 18  that determines the position of the lower side of the FPC  200 C and a positioning portion PT 18  that determines the position of the edge portion of the FPC  200 C. The positioning portions PT 18  and PT 19  project, for example, in the +Y direction. The positioning portion PT 18  extends in the X direction, and the positioning portion PT 19  extends in the Z direction. 
     Of two sides of the FPC  200 C along the X direction, a part of the side in the −Z direction functions as the positioning portion PT 28 . Of two sides of the FPC  200 C along the Z direction, a part of the side close to the detection electrode  220  functions as the positioning portion PT 29 . 
     The FPC  200 C is the same as the FPC  200  shown in  FIG.  3    except that the FPC  200 C includes a detection electrode  220   c  provided in the second arrangement portion PP 2 , a wiring  222   c  coupled to the detection electrode  220   c , and a shield wiring  240   f . For example, the detection electrode  220   c , the wiring  222   c , and the shield wiring  240   f  are formed of the same material as the input electrode  210  and are formed on the first conductor layer  202 . For example, the wiring  222   c  is formed integrally with the detection electrode  220   c.    
     The shield wiring  240   f  is located between the wiring  222   c  integrally formed with the detection electrode  220   c  and the wiring  222   b  integrally formed with the detection electrode  220   b . The shield wiring  240   f  can reduce the interference between the detection electrodes  220   b  and  220   c.    
     The detection electrode  220   c  is located between the shield wiring  240   f  and the shield wiring  240   b . Further, the detection electrode  220   c  is the detection electrode  220  closest to the supply port  160  among the detection electrodes  220   a ,  220   b  and  220   c . For example, the detection electrode  220   c  functions as an upper limit electrode for detecting whether or not the storage amount of the ink INK stored in the ink tank  100 C is an upper limit storage amount. In this modification example, the detection electrode  220   c  extends in the X direction. Further, the position of the discharge port Hd in the X direction and the position of the detection electrode  220   c  in the X direction are different from each other. For example, the range of the discharge port Hd in the X direction does not overlap the range of the detection electrode  220   c  in the X direction. Further, at least a part of the range of the detection electrode  220   c  in the X direction overlaps at least a part of the range of the supply port  160  in the X direction. Therefore, in this modification example, when the storage amount of the ink INK exceeds the upper limit storage amount at the time of supplying the ink INK, it is possible to reduce the delay of the detection that the storage amount of the ink INK exceeds the upper limit storage amount. 
     The configurations of the ink tank  100 C and the FPC  200 C are not limited to the example shown in  FIG.  24   . For example, the positioning portions PT 18  and PT 19  may be omitted. Further, for example, the detection electrode  220   c  may be arranged such that the position in the X direction is the same as the detection electrodes  220   a  and  220   b.    
     As described above, also in this modification example, the same effect as that of the above-described embodiment and modification example can be obtained. Further, in this modification example, the tank unit  10  includes the detection electrode  220   c  provided in the second arrangement portion PP 2 . Thereby, in this modification example, the storage amount of the ink INK can be detected in multiple stages. 
     Further, in this modification example, the ink tank  100 C includes the supply port  160  for supplying the ink INK to the space SP. The detection electrodes  220   b  and  220   c  include the upper limit electrode for detecting whether or not the storage amount of the ink INK stored in the ink tank  100 C is the upper limit storage amount. Of the detection electrodes  220   a ,  220   b  and  220   c , the detection electrode  220  that functions as the upper limit electrode is closest to the supply port  160 . In this modification example, the detection electrode  220   c  can detect whether or not the storage amount of the ink INK is the upper limit storage amount. 
     Further, in this modification example, the detection electrode  220   c  extends in the X direction. Further, the position of the discharge port Hd in the X direction and the position of the detection electrode  220   c  in the X direction are different from each other. At least a part of the range of the detection electrode  220   c  in the X direction overlaps at least a part of the range of the supply port  160  in the X direction. Therefore, in this modification example, when the storage amount of the ink INK exceeds the upper limit storage amount at the time of supplying the ink INK, it is possible to reduce the delay of the detection that the storage amount of the ink INK exceeds the upper limit storage amount. 
     Sixth Modification Example 
     In the above-described embodiment and modification examples, a film such as a nylon film may be adhered to the outer surface OF 2  of the outer wall  120   b . That is, a film may be provided between the outer wall  120   b  and the FPC  200 . Further, both the outer walls  120   a  and  120   b  may be formed of a film such as a nylon film. Alternatively, the outer wall  120   b  may be formed of a film such as a nylon film, and the outer wall  120   a  may be formed of a plastic having a higher elastic modulus than the outer wall  120   b.    
     Seventh Modification Example 
     In the above-described embodiment and modification examples, the ink jet printer  1  in which the tank unit  10  is not mounted on the carriage  32  is exemplified, but the present disclosure is not limited to such an aspect. For example, the tank unit  10  may be mounted on the carriage  32  or may be mounted on an ink server that supplies the ink INK to a printing apparatus. Further, the “liquid ejection apparatus” is not limited to the ink jet printer  1 , and may be another printing apparatus. Further, the “storage device” is not limited to the tank unit  10  that stores the ink INK. For example, the “storage device” may be a device for storing an object other than the ink INK. That is, the “object” is not limited to the ink INK. For example, the “object” may be a liquid other than the ink INK, or may be a fluid. For example, the “object” may be oil. 
     Eighth Modification Example 
     In the above-described embodiment and modification examples, the support portion  130  may be omitted. Further, a flexible flat cable may be used instead of the FPC  200 . 
     Ninth Modification Example 
     In the above-described embodiment and modification examples, a case where the discharge port Hd is located near the center of the outer wall  120   e  has been exemplified, but the present disclosure is not limited to such an aspect. For example, the discharge port Hd may be formed in the vicinity of one of the edge portions EP 1  and EP 2  of the outer wall  120   e . Further, when the discharge port Hd is seen from the −Z direction, an aspect in which the discharge port Hd is not located between the input electrode  210  and the detection electrode  220  may be adopted. Further, even when the discharge port Hd is located near the center of the outer wall  120   e , an aspect in which the discharge port Hd is not located between the input electrode  210  and the detection electrode  220  when the discharge port Hd is seen from the −Z direction may be adopted.