Patent Publication Number: US-9834004-B2

Title: Flow channel structure and liquid ejecting apparatus

Description:
BACKGROUND 
     1. Technical Field 
     The present invention relates to a structure of a flow channel where a liquid such as an ink flows. 
     2. Related Art 
     Various types of structures for supplying a liquid to a liquid ejecting head which ejects the liquid such as an ink from a plurality of nozzles have been offered. For example, in JP-A-2011-46070, a configuration of forming a flow channel where a filter or a pressure regulating damper is installed in an internal portion by welding a polypropylene (PP) film or a polyethylene terephthalate (PET) film onto both of surfaces of a main body portion has been disclosed. In the configuration of JP-A-2011-46070, a valve for controlling opening and closing of the flow channel is installed on the flow channel. 
     In the configuration of installing the valve on the flow channel as described in JP-A-2011-46070, there are problems that a pressure difference between a space of an upstream side of the valve and a space of a downstream side of the valve becomes significant, and deformation or breakage of the space is likely to occur in a high pressure side as compared with a low pressure side. 
     SUMMARY 
     An advantage of some aspects of the invention is to reduce a possibility of deformation or breakage of a space which configures a flow channel. 
     Aspect 1 
     According to a preferable example (Aspect 1) of the invention, there is provided a flow channel structure including a first flow channel chamber to which a liquid is supplied, a first sealing body that configures a wall face of the first flow channel chamber, a valve body that controls flow and blocking of the liquid in accordance with deformation of the first sealing body, a second flow channel chamber that communicates with the first flow channel chamber, and a second sealing body that configures a wall face of the second flow channel chamber, in which the rigidity of the second sealing body is greater than the rigidity of the first sealing body. In Aspect 1, since the rigidity of the second sealing body is greater than the rigidity of the first sealing body, for example, it is possible to reduce a possibility of deformation or breakage of the second flow channel chamber in comparison with a case where the rigidity of the second sealing body is equal to the rigidity of the first sealing body. 
     Aspects 2 and 3 
     According to a preferable example (Aspect 2) of Aspect 1, the second flow channel chamber may be positioned on an upstream side of the first flow channel chamber, and an internal pressure of the second flow channel chamber may be higher than that of the first flow channel chamber. According to a preferable example (Aspect 3) of Aspect 2, for example, the internal pressure of the second flow channel chamber may be from 30 kPa to 40 kPa. In Aspect 2 or 3, the internal pressure of the second flow channel chamber is higher than that of the first flow channel chamber. Therefore, some aspects of the invention which can reduce the possibility of the deformation or the breakage of the second flow channel chamber are particularly suitable. 
     Aspect 4 
     According to a preferable example (Aspect 4) of Aspect 2 or 3, a first filter that faces the second sealing body by being installed in the second flow channel chamber may be further included. Since the deformation of the second sealing body is controlled by the configuration in which the rigidity of the second sealing body is greater than the rigidity of the first sealing body as described above, it is possible to reduce the possibility of closing the first filter by that the second sealing body is in contact with the first filter due to the deformation in Aspect 4. 
     Aspect 5 
     According to a preferable example (Aspect 5) of any one of Aspects 1 to 4, a base body where the first sealing body and the second sealing body are installed may be further included. In Aspect 5, since the first sealing body and the second sealing body are installed in the common base body, for example, there is an advantage that the flow channel structure is miniaturized in comparison with a configuration of installing the first sealing body and the second sealing body in components which are different from each other. 
     Aspect 6 
     According to a preferable example (Aspect 6) of Aspect 5, a protruding portion that is installed on a surface of the base body may be further included, and a protruding engagement portion which engages with the protruding portion may be formed in the second sealing body. According to Aspect 6, it is possible to determine a position of the second sealing body by that the protruding engagement portion of the second sealing body engages with the protruding portion on the surface of the base body. 
     Aspect 7 
     According to a preferable example (Aspect 7) of Aspect 5 or 6, a sealing body engagement portion of a shape correlating with the first sealing body may be formed in the second sealing body, and the first sealing body may engage with the sealing body engagement portion. According to Aspect 7, it is possible to determine a position of the first sealing body by that the first sealing body engages with the sealing body engagement portion of the second sealing body. 
     Aspect 8 
     According to a preferable example (Aspect 8) of Aspect 6, a protruding engagement portion which engages with the protruding portion may be formed in the first sealing body. According to Aspect 8, it is possible to determine the positions of the first sealing body and the second sealing body by that the protruding engagement portions of the first sealing body and the second sealing body engage with the common protruding portion. 
     Aspect 9 
     According to a preferable example (Aspect 9) of any one of Aspects 5 to 8, the second sealing body may be fixed to a joining portion which protrudes from the surface of the base body, the joining portion may include a first portion surrounding the second flow channel chamber in a planar view, and a second portion surrounding a flow channel which communicates with the second flow channel chamber in the planar view, and the first portion and the second portion may have the same portion between the second flow channel chamber and the flow channel. In Aspect 9, since the first portion and the second portion of the joining portion for fixing the second sealing body have the same portion, there is an advantage that the area which is necessary for the formation of the joining portion is reduced (in addition to that it is possible to miniaturize the flow channel structure) in comparison with a configuration of independently forming the first portion and the second portion to be separated from each other. 
     Aspect 10 
     According to a preferable example (Aspect 10) of Aspect 1, a first filter that faces the second sealing body by being installed in the second flow channel chamber may be further included, and the second flow channel chamber may be positioned on a downstream side of the first flow channel chamber. Since the deformation of the second sealing body is controlled by the configuration in which the rigidity of the second sealing body is greater than the rigidity of the first sealing body as described above, it is possible to reduce the possibility of closing the first filter by that the second sealing body is in contact with the first filter due to the deformation in Aspect 10. 
     Aspect 11 
     According to a preferable example (Aspect 11) of Aspect 10, a base body that includes a first face and a second face which are positioned on opposite sides to each other may be further included, and the first sealing body may be installed on the first face, and the second sealing body may be installed on the second face. In Aspect 11, since the first sealing body and the second sealing body are installed on the opposite sides to each other by interposing the base body therebetween, there is an advantage that a size of the flow channel structure may be reduced in comparison with a configuration of installing the first sealing body and the second sealing body on the surface of one side of the base body so as not to overlap with each other. 
     Aspect 12 
     According to a preferable example (Aspect 12) of Aspect 10 or 11, a second filter that is arranged on an upstream side of the first flow channel chamber may be further included, and the first filter may have a fine mesh, and a large area in comparison with the second filter. According to Aspect 12, it is possible to supply the liquid to the downstream side after collecting a minute foreign material or air bubbles by the first filter of which the mesh is fine in comparison with the second filter. Meanwhile, since the first filter has the large area in comparison with the second filter, flow channel resistance of the first filter is suppressed in spite of the configuration in which the mesh of the first filter is fine. 
     Aspect 13 
     According to a preferable example (Aspect 13) of any one of Aspects 10 to 12, at least a portion the first filter, and at least a portion of the first flow channel chamber may overlap with each other when viewed from a direction which is perpendicular to the wall face of the first sealing body or the second sealing body. In Aspect 13, since the first filter and the first flow channel chamber overlap with each other, it is possible to reduce the size of the flow channel structure in comparison with a configuration in which the first filter and the second flow channel chamber do not overlap with each other. 
     Aspect 14 
     According to a preferable example (Aspect 14) of any one of Aspects 10 to 13, the area of the first filter may be 50% or more of the area of the first flow channel chamber. More preferably, the area of the first filter may be 90% or more (ideally, 100%) of the area of the first flow channel chamber. According to Aspect 14, there is an advantage that the flow channel resistance may be effectively suppressed by sufficiently securing the area of the first filter. 
     Aspect 15 
     According to a preferable example (Aspect 15) of any one of Aspects 10 to 14, the second sealing body may be transparent. In Aspect 15, since the second sealing body is transparent, there is an advantage that the air bubbles or the foreign materials which are collected by the first filter can be visually confirmed through the second sealing body (in addition to that it is possible to determine whether or not an exchange of the first filter is necessary). 
     Aspect 16 
     According to a preferable example (Aspect 16) of Aspect 3 or 10, the first filter may be fixed to an installation portion which protrudes from the surface of the base body, the second sealing body may be fixed to a joining portion which protrudes from the surface of the base body, and a groove portion for heat radiation may be formed between the installation portion and the joining portion in the base body. In Aspect 16, since the groove portion for heat radiation is formed between the installation portion and the joining portion, for example, there is an advantage of reducing the possibility that the heat radiates up to the joining portion in a process of welding the first filter to the installation portion. 
     Aspect 17 
     According to a preferable example (Aspect 17) of Aspect 5 or 11, the base body may absorb a laser beam, and the second sealing body may transmit the laser beam. In Aspect 17, it is possible to fix the second sealing body to the base body by a laser welding of irradiating and melting the base body with the laser beam which is transmitted through the second sealing body. 
     Aspect 18 
     According to a preferable example (Aspect 18) of the invention, there is provided a liquid ejecting apparatus including the flow channel structure according to any one of Aspect 1 to Aspect 17, and a liquid ejecting head that ejects a liquid which is supplied from the flow channel structure. The liquid ejecting apparatus is preferably a printing apparatus which ejects an ink, but an application of the liquid ejecting apparatus according to Aspect 18 of the invention is not limited to the printing. 
     Aspect 19 
     According to a preferable example (Aspect 19) of the invention, there is provided a liquid ejecting apparatus including a first liquid ejecting unit including the flow channel structure according to any one of Aspect 1 to Aspect 17, and a liquid ejecting head that ejects a liquid which is supplied from the flow channel structure, and a second liquid ejecting unit including the flow channel structure according to any one of Aspect 1 to Aspect 17, and a liquid ejecting head that ejects a liquid which is supplied from the flow channel structure, in which the first sealing body of the flow channel structure of the first liquid ejecting unit, and the first sealing body of the flow channel structure of the second liquid ejecting unit face each other. In Aspect 19, since the first liquid ejecting unit and the second liquid ejecting unit are installed so that the first sealing bodies of the rigidity which is low in comparison with the second sealing body face each other, for example, there is an advantage that the first sealing bodies of the respective liquid ejecting units can be protected from a collision with an external component, for example, in comparison with a configuration in which the first sealing bodies of the respective liquid ejecting units are positioned on the opposite sides to each other. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a configuration diagram of a printing apparatus according to a first embodiment of the invention. 
         FIG. 2  is a perspective view of a liquid ejecting unit. 
         FIG. 3  is a diagram for describing an internal flow channel of a flow channel structure. 
         FIG. 4  is a configuration diagram of the flow channel structure. 
         FIG. 5  is a plan view of a first face of a base body in the flow channel structure. 
         FIG. 6  is a plan view of a second face of a base body in the flow channel structure. 
         FIG. 7  is a sectional view taken along line VII-VII in  FIG. 4 . 
         FIG. 8  is a sectional view taken along line VIII-VIII in  FIG. 4 . 
         FIG. 9  is a diagram for describing a sealing body. 
         FIG. 10  is a diagram for describing support of a plurality of liquid ejecting units in a second embodiment. 
         FIG. 11  is a plan view of a flow channel structure in a third embodiment. 
         FIG. 12  is a diagram for describing an internal flow channel of the flow channel structure in the third embodiment. 
         FIG. 13  is a diagram for describing a joining portion and a sealing body in the third embodiment. 
         FIG. 14  is a diagram for describing the joining portion and the sealing body in the third embodiment. 
         FIG. 15  is a sectional view for describing the vicinity of an adjusting mechanism in the third embodiment. 
         FIG. 16  is a configuration diagram of Modification Example of the third embodiment. 
         FIG. 17  is a diagram for describing positioning of a sealing body in Modification Example. 
         FIG. 18  is a diagram for describing the positioning of the sealing body in Modification Example. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     First Embodiment 
       FIG. 1  is a partial configuration diagram of an ink jet type printing apparatus  10  according to a first embodiment of the invention. The printing apparatus  10  of the first embodiment is a liquid ejecting apparatus that ejects an ink being an example of a liquid onto a medium (ejecting target)  12  such as printing paper. As illustrated in  FIG. 1 , the printing apparatus  10  includes a control apparatus  22 , a transport mechanism  24 , a plurality of liquid ejecting units  26 , and a carriage  28 . A liquid container (cartridge)  14  which stores the ink is installed in the printing apparatus  10 . 
     The control apparatus  22  generally controls each of components of the printing apparatus  10 . The transport mechanism  24  transports the medium  12  in a Y direction on the basis of a control by the control apparatus  22 . The respective liquid ejecting units  26  eject the ink which is supplied from the liquid container  14  onto the medium  12  from each of a plurality of nozzles N on the basis of the control by the control apparatus  22 . The plurality of liquid ejecting units  26  of the first embodiment are mounted in the carriage  28 . The control apparatus  22  makes the carriage  28  reciprocate in an X direction intersecting with the Y direction. A desired image is formed on a surface of the medium  12  by that the respective liquid ejecting units  26  eject the ink onto the medium  12  in parallel with a repeat of the transport of the medium  12  and the reciprocation of the carriage  28 . 
       FIG. 2  is a perspective view of any one of the liquid ejecting units  26 . As illustrated in  FIG. 2 , the liquid ejecting unit  26  of the first embodiment includes a flow channel structure  32 , a liquid ejecting head  34 , and a wiring circuit board  36 . The flow channel structure  32  of the first embodiment is a structure of a substantially flat plate shape that includes a supply flow channel (supply port) P 1 , and a discharge flow channel (discharge port) P 2 . The flow channel structure  32  discharges the ink which is supplied to the supply flow channel P 1  from the liquid container  14 , to the discharge flow channel P 2  through an internal flow channel. The liquid ejecting head  34  is connected to the discharge flow channel P 2  of the flow channel structure  32  through a supply pipe  38 , and ejects the ink which is supplied from the discharge flow channel P 2  of the flow channel structure  32  through the supply pipe  38 , from the plurality of nozzles N. Specifically, the liquid ejecting head  34  includes a plurality of sets (not illustrated) of a pressure chamber and a piezoelectric element correlating with the nozzles N which are different from each other. As illustrated in  FIG. 2 , for example, the wiring circuit board  36  having flexibility such as a flexible printed circuit (FPC) or a flexible flat cable (FFC) is connected to the liquid ejecting head  34 . A wiring which supplies a drive signal and a power supply voltage for driving each piezoelectric element from an external apparatus such as the control apparatus  22  to the liquid ejecting head  34 , is formed in the wiring circuit board  36 . A pressure within the pressure chamber is changed by vibrating the piezoelectric element depending on the drive signal and the power supply voltage which are supplied through the wiring circuit board  36 , and thereby, the ink with which the pressure chamber is filled is ejected from each nozzle N. 
       FIG. 3  is a diagram for describing the flow channel which is formed in an internal portion of the flow channel structure  32 . As illustrated in  FIG. 3 , the flow channel structure  32  of the first embodiment includes a plurality of flow channels Q (QA, QB, QC), and a plurality of flow channel chambers R (RA, RB, RC) between the supply flow channel P 1  and the discharge flow channel P 2 . Each flow channel Q is a flow channel where the ink flows, and each flow channel chamber R is a space which communicates with each flow channel Q. 
     As illustrated in  FIG. 3 , the flow channel chamber RA is a space which communicates with each of the supply flow channel P 1  and the flow channel QA by being formed between the supply flow channel P 1  and the flow channel QA. A filter FA (example of a second filter) is installed in the flow channel chamber RA. The filter FA collects air bubbles or a foreign material from the ink which is supplied to the flow channel chamber RA from the supply flow channel P 1 . The ink where the air bubbles or the foreign materials are removed by passing through the filter FA is supplied to the flow channel QA from the flow channel chamber RA. 
     The flow channel chamber RB is a space (example of a first flow channel chamber) communicating with each of the flow channel QA and the flow channel QB by being formed therebetween. An adjusting mechanism B is installed between the flow channel QA and the flow channel chamber RB. The adjusting mechanism B of the first embodiment is a valve mechanism that controls opening and closing (opening and blocking) of the flow channel QA depending on the pressure (negative pressure) within the flow channel chamber RB. The ink flowing into the flow channel chamber RB from the flow channel QA is supplied to the flow channel QB in a state where the adjusting mechanism B opens the flow channel QA. 
     The flow channel chamber RC is a space (example of a second flow channel chamber) which communicates with each of the flow channel QB and the flow channel QC by being formed between the flow channel QB and the flow channel QC. A filter FB (example of a first filter) is installed in the flow channel chamber RC. The filter FB collects the air bubbles or the foreign material from the ink which is supplied to the flow channel chamber RC from the flow channel QB. The ink passing through the filter FB is supplied to the flow channel QC, and is supplied to the liquid ejecting head  34  from the discharge flow channel P 2  which communicates with the flow channel QC. 
     As understood from the above description, the flow channel QB (second flow channel) is positioned on a downstream side of the flow channel QA (first flow channel), and the flow channel QC (third flow channel) is positioned on the downstream side of the flow channel QB. Moreover, the filter FA is installed on an upstream side of the adjusting mechanism B, and the filter FB is installed on the downstream side of the adjusting mechanism B. 
       FIG. 4  is a configuration diagram of the flow channel structure  32 . As illustrated in  FIG. 2  and  FIG. 4 , the flow channel structure  32  of the first embodiment includes a base body  42 , a sealing body  44  (example of a first sealing body), and a sealing body  46  (example of a second sealing body). The base body  42  is a structure of a substantially flat plate shape that includes a first face  42 A, and a second face  42 B which are positioned on opposite sides to each other. For example, the base body  42  is formed by an injection molding of a resin material. The base body  42  of the first embodiment is formed of polypropylene (PP). As illustrated in  FIG. 4 , the supply flow channel P 1  having a substantially circular pipe shape is formed on an upper face of the base body  42 , and the discharge flow channel P 2  having a substantially circular pipe shape is formed on a bottom face of the base body  42 . For example, each of the sealing body  44  and the sealing body  46  are flat plate-shaped (film-shaped) members which are formed of the resin materials. The sealing body  44  is joined to the first face  42 A of the base body  42 , and the sealing body  46  is joined to the second face  42 B of the base body  42 . In  FIG. 4 , a portion of the sealing body  44  and the sealing body  46  is broken for convenience of the description. 
       FIG. 5  is a plan view of the first face  42 A of the base body  42 , and  FIG. 6  is a plan view of the second face  42 B of the base body  42 . As illustrated in  FIG. 5 , a concave portion  52 , a groove portion  54 , and a groove portion  56  are formed on the first face  42 A of the base body  42 , and are sealed by the sealing body  44  which is joined to the first face  42 A. The concave portion  52  is a hollow portion which is low in comparison with the first face  42 A, and is formed into a substantially circular shape in a planar view (that is, when viewed from a direction which is perpendicular to the first face  42 A or the second face  42 B). A space which is surrounded by an internal face of the concave portion  52  and a surface (referred to as “sealing face”, hereinafter) of the base body  42  side among the sealing body  44  functions as the flow channel chamber RB. As illustrated in  FIG. 4 , a portion (referred to as “first wall portion”, hereinafter)  442  of a circular shape which is positioned on the inside of the concave portion  52  among the sealing body  44  in the planar view, configures a wall face of the flow channel chamber RB by being installed on the first face  42 A of the base body  42 . 
     As illustrated in  FIG. 6 , a concave portion  62 , a concave portion  64 , and a groove portion  66 , a groove portion  68  are formed on the second face  42 B of the base body  42 , and are sealed by the sealing body  46  which is joined to the second face  42 B. Each of the concave portion  62  and the concave portion  64  are hollow portions which are low in comparison with the second face  42 B, and are formed into the substantially circular shapes in the planar view. As understood from  FIG. 4  and  FIG. 6 , a space which is surrounded by the internal face of the concave portion  62  and the sealing face of the base body  42  side among the sealing body  46  functions as the flow channel chamber RA, and a space which is surrounded by the internal face of the concave portion  64  and the sealing face of the sealing body  44  functions as the flow channel chamber RC. The flow channel chamber RA communicates with the supply flow channel P 1  through a communication hole H 1  of the base body  42 . As understood from the above description, the flow channel chamber RB is formed on the first face  42 A side of the base body  42 , and the flow channel chamber RA and the flow channel chamber RC are formed on the second face  42 B side of the base body  42 . 
     A space which is surrounded by the internal face of the groove portion  54  of the first face  42 A and the sealing face of the sealing body  44  correlates with a portion QA 1  of the upstream side (flow channel chamber RA side) among the flow channel QA, and a space which is surrounded by the groove portion  66  of the second face  42 B and the sealing face of the sealing body  46  correlates with a portion QA 2  of the downstream side (flow channel chamber RB side) among the flow channel QA. As illustrated in  FIG. 5 , an end portion of the upstream side of the portion QA 1  (groove portion  54 ) of the flow channel QA, communicates with the flow channel chamber RA through a communication hole H 2  penetrating the base body  42 . Moreover, as illustrated in  FIG. 5  and  FIG. 6 , among the flow channel QA, the end portion of the downstream side of the portion QA 1  (groove portion  54 ) of the first face  42 A side, and the end portion of the upstream side of the portion QA 2  (groove portion  66 ) of the second face  42 B side communicate with each other through a communication hole H 3  penetrating the base body  42 . 
     A space which is surrounded by the internal face of the groove portion  68  of the second face  42 B and the sealing face of the sealing body  46  correlates with the flow channel QB of  FIG. 3 . The end portion of the upstream side of the flow channel QB communicates with the flow channel chamber RB of the first face  42 A side through a communication hole H 4  penetrating the base body  42 . Moreover, by forming the groove portion  68  so as to be continuous to the concave portion  64  within the face of the second face  42 B, the end portion of the downstream end of the flow channel QB communicates with the flow channel chamber RC. On the other hand, a space which is surrounded by the internal face of the groove portion  56  of the first face  42 A and the sealing face of the sealing body  44  correlates with the flow channel QC of  FIG. 3 . As illustrated in  FIG. 5  and  FIG. 6 , the end portion of the upstream side of the flow channel QC communicates with the flow channel chamber RC of the second face  42 B side through a communication hole H 5  penetrating the base body  42 , and the end portion of the downstream side of the flow channel QC communicates with the discharge flow channel P 2  through a communication hole H 6 . A specific structure of the flow channel which is from the supply flow channel P 1  to the discharge flow channel P 2  is configured as described above. 
       FIG. 7  is a sectional view (sectional view of the flow channel chamber RB) taken along line VII-VII in  FIG. 4 . As illustrated in  FIG. 7 , the adjusting mechanism B of  FIG. 3  is installed so as to overlap with the flow channel chamber RB in the planar view. As illustrated in  FIG. 7 , the adjusting mechanism B of the first embodiment includes a valve body  72 , a valve seat  74 , a pressure plate  76 , a support plate  78 , a spring S 1 , and a spring S 2 . The valve seat  74  is a portion which configures the bottom face of the flow channel chamber RB (concave portion  52 ), and faces the first wall portion  442  of the sealing body  44  at intervals. A communication hole  742  penetrating the base body  42  is formed in a central portion of the valve seat  74 . The pressure plate  76  is a flat plate member of the substantially circular shape which is installed on a facing face (specifically, the central portion of the first wall portion  442 ) of the valve seat  74  among the first wall portion  442 . 
     The support plate  78  is installed on the opposite side to the sealing body  44  (first wall portion  442 ) by interposing the valve seat  74  therebetween, and faces the valve seat  74  at intervals. A space (referred to as “valve chamber”, hereinafter)  75  between the valve seat  74  and the support plate  78  communicates with the flow channel QA (portion QA 2 ) through a communication hole (slit)  782  which is formed in the support plate  78 . That is, a flow channel which reaches the flow channel chamber RB through the communication hole  782  of the support plate  78 , the valve chamber  75 , and the communication hole  742  of the valve seat  74  from the flow channel QA, is formed. 
     As illustrated in  FIG. 7 , the valve body  72  includes a base portion  722 , a valve shaft  724 , and a sealing portion (seal)  726 . The valve shaft  724  perpendicularly protrudes from the surface of the base portion  722 , and the sealing portion  726  of an annular shape which surrounds the valve shaft  724  in the planar view is installed on the surface of the base portion  722 . The valve body  72  is installed so that the base portion  722  and the sealing portion  726  are positioned within the valve chamber  75  in a state where the valve shaft  724  is inserted into the communication hole  742  of the valve seat  74 . That is, the base portion  722  and the sealing portion  726  of the valve body  72  are positioned on the opposite side to the pressure plate  76  (flow channel chamber RB) by interposing the valve seat  74  therebetween, and a tip portion of the valve shaft  724  that is inserted into the communication hole  742  of the valve seat  74  faces the pressure plate  76  within the flow channel chamber RB. The sealing portion  726  is positioned between the base portion  722  and the valve seat  74 . A diameter of the valve shaft  724  is smaller than an internal diameter of the communication hole  742  of the valve seat  74 . Therefore, a gap is formed between an inner circumferential face of the communication hole  742  of the valve seat  74  and an outer circumferential face of the valve shaft  724 . The spring S 1  of  FIG. 7  biases the valve body  72  toward the valve seat  74  side by being installed between the support plate  78  and the base portion  722  of the valve body  72 . On the other hand, the spring S 2  is installed between the valve seat  74  and the pressure plate  76 . 
     In the above configuration, since the sealing portion  726  is stuck and pressed to the surface of the valve seat  74  by that the spring S 1  biases the valve body  72 , the flow channel chamber RB and the valve chamber  75  are blocked, in the normal state where the pressure of the flow channel chamber RB is maintained within a predetermined range. That is, the flow channel QA is closed. On the other hand, for example, if the negative pressure within the flow channel chamber RB is increased due to the ejection of the ink by the liquid ejecting head  34  or the suction from the outside, the first wall portion  442  configuring the wall face of the flow channel chamber RB among the sealing body  44  is moved to the valve seat  74  side, and the pressure plate  76  which is installed in the first wall portion  442  presses the valve shaft  724  of the valve body  72  against the biasing by the spring S 2 . In other words, the first wall portion  442  functions as a diaphragm which is deformed depending on the pressure (negative pressure) within the flow channel chamber RB. If the negative pressure within the flow channel chamber RB is further increased, the sealing portion  726  is separated from the surface of the valve seat  74  by displacing the valve body  72  to the support plate  78  side against the biasing by the spring S 1 . Therefore, the valve chamber  75  communicating with the flow channel QA, communicates with the flow channel chamber RB through the communication hole  742  of the valve seat  74 . That is, the channel QA is opened. In the state where the flow channel QA is opened, the ink which is supplied through the supply flow channel P 1 , the flow channel chamber RA and the flow channel QA from the liquid container  14 , is supplied to the flow channel chamber RB through the valve chamber  75  and the communication hole  742 . If the negative pressure of the flow channel chamber RB is decreased by the ink supply from the flow channel QA, the valve body  72  is displaced to the sealing body  44  side by the biasing of the spring S 1 , and the sealing portion  726  is in contact with the surface of the valve seat  74 . In other words, the valve chamber  75  communicating with the flow channel QA, and the flow channel chamber RB are blocked. As understood from the above description, the valve body  72  of the first embodiment controls the opening and the closing (flow and blocking of the ink) between the flow channel QA and the flow channel chamber RB in accordance with the deformation of the first wall portion  442 . 
     Next,  FIG. 8  is a sectional view (sectional view of the flow channel chamber RC) taken along line VIII-VIII in  FIG. 4 . As illustrated in  FIG. 8 , the filter FB of the circular shape is installed within the flow channel chamber RC. The filter FB is installed in the internal portion of the flow channel chamber RC so as to face a portion (referred to as “second wall portion”, hereinafter)  462  which is positioned on the inside of the concave portion  64  among the sealing body  46  in the planar view at intervals, and to face the bottom face of the concave portion  64  at intervals. That is, the flow channel chamber RC is partitioned into the upstream side and the downstream side by interposing the filter FB therebetween. 
     As understood from the above description, the second wall portion  462  faces the filter FB by being installed on the second face  42 B of the base body  42 , and configures the wall face of the flow channel chamber RC. That is, in the first embodiment, the first wall portion  442  is installed on the first face  42 A of the base body  42 , and the second wall portion  462  is installed on the second face  42 B which is the opposite side to the first face  42 A. Therefore, there is an advantage that a size of the flow channel structure  32  may be reduced in comparison with a configuration of installing the first wall portion  442  and the second wall portion  462  on the surface of one side of the base body  42  so as not to overlap with each other. Furthermore,  FIG. 7  focuses on the filter FB within the flow channel chamber RC, but the filter FA is installed in the flow channel chamber RA by the configuration which is similar thereto. That is, the filter FA is installed within the flow channel chamber RA so as to face each of the sealing face of the sealing body  46  and the bottom face of the concave portion  62  at intervals. The ink passes through to the first face  42 A side from the second face  42 B side in all of the filter FA and the filter FB. 
     In the first embodiment, the sealing body  44  and the sealing body  46  are different from each other in rigidity (bending rigidity). Specifically, the rigidity of the sealing body  44  is lower than the rigidity of the sealing body  46 . That is, the sealing body  44  is likely to be deformed in comparison with the sealing body  46 . For example, in a configuration in which the sealing body  44  and the sealing body  46  are formed into the same plate thicknesses, a Young&#39;s modulus EA of the sealing body  44  is smaller than a Young&#39;s modulus EB of the sealing body  46  (EA&lt;EB). Moreover, in a configuration in which the sealing body  44  and the sealing body  46  are formed of materials of the same Young&#39;s modulus, a plate thickness TA of the sealing body  44  is smaller than a plate thickness TB of the sealing body  46  (TA&lt;TB). As understood from the above description, the rigidity of the first wall portion  442  is lower than the rigidity of the second wall portion  462 . In other words, the first wall portion  442  is set to the low rigidity so as to be deformed depending on the negative pressure of the flow channel chamber RB, and the second wall portion  462  configuring the wall face of the flow channel chamber RC is set to be the high rigidity so as not to be deformed even when the pressure of the flow channel chamber RC is changed. 
     In the configuration of JP-A-2011-46070, the filter for collecting the foreign material or the air bubbles of the liquid is installed in the space where the concave portion which is formed on the surface of the main body portion is sealed by the film. However, in the configuration in which the film faces the surface of the filter as described in JP-A-2011-46070, for example, when the film is deformed to the inside due to the occurrence of the negative pressure within the space, there is a possibility that the film is in contact with the surface of the filter. Since a flow channel area is reduced if the filter is partially closed by the contact of the film, a problem such as the increase of the pressure loss within the flow channel or the decrease of the foreign material collecting performance by the filter, occurs. On the other hand, in the first embodiment, since the rigidity of the second wall portion  462  is greater than the rigidity of the first wall portion  442 , for example, the deformation of the second wall portion  462  is suppressed, in comparison with a configuration in which the rigidity of the second wall portion  462  is the same as the rigidity of the first wall portion  442 . That is, for example, even when the negative pressure occurs in the flow channel QC due to the ejection of the ink by the liquid ejecting head  34  or the suction from the outside, the possibility of deforming the second wall portion  462  so as to be in contact with the filter FB is reduced. Therefore, the reduction of the flow channel area is suppressed by the contact with the second wall portion  462  and the filter FB, and it is possible to solve the problem such as the increase of the pressure loss or the decrease of the collecting performance of the filter FB. Moreover, there is a tendency that a time-dependent change of mechanical properties is unlikely to occur in the second wall portion  462  of the high rigidity in comparison with the member (for example, the first wall portion  442 ) of the low rigidity. Therefore, there is an advantage that the time-dependent change of flow channel properties of the flow channel structure  32  such as the pressure (holding pressure) of the flow channel chamber RB or the negative pressure (working pressure) of displacing the valve body  72  in the normal state where the flow channel QA is closed by the valve body  72  may be suppressed, in comparison with the configuration in which the rigidity of the second wall portion  462  is the same as the rigidity of the first wall portion  442 . 
     As illustrated in  FIG. 6 , the filter FB has the large area (large diameter) in comparison with the filter FA. For example, the area of the filter FB is 50% or more (more preferably, 90% or more) of the area of the flow channel chamber RB, and is ideally the same (100%) as that of the flow channel chamber RB. On the other hand, the filter FA has the small area (small diameter) in comparison with the flow channel chamber RB. Moreover, the filter FB has a fine mesh in comparison with the filter FA. Specifically, an internal diameter of a through hole (or gap of the mesh) where the ink passes through in the filter FB is smaller than that of the filter FA. Therefore, the filter FB may collect the small foreign material or the small air bubbles in comparison with the filter FA of the upstream side. The flow channel resistance is apt to be increased as much as the mesh becomes fine, but in the first embodiment, since the filter FB is formed into the large area in comparison with the filter FA, there is an advantage that the flow channel resistance of the filter FB may be suppressed in comparison with a case where the area of the filter FB is the same as the area of the filter FA. 
     As understood from  FIG. 5  and  FIG. 6 , in the first embodiment, the flow channel chamber RB and the filter FB (flow channel chamber RC) partially overlap with each other in the planar view. Therefore, for example, there is an advantage that the size of the flow channel structure  32  may be reduced as the overlapping portion of the flow channel chamber RB and the filter FB, in comparison with a configuration in which the flow channel chamber RB and the filter FB do not overlap with each other. In the first embodiment, since the filter FB of the large area is adopted in order to reduce the flow resistance as described above, an effect that the size of the flow channel structure  32  may be reduced by the overlapping of the flow channel chamber RB and the filter FB is particularly effective. 
       FIG. 9  is a sectional view of the sealing body  44 . As illustrated in  FIG. 9 , the sealing body  44  of the first embodiment is configured by stacking a first layer L 1 , an adhesive layer L 0 , and a second layer L 2 . For example, the first layer L 1  is formed of polypropylene (PP) in the same manner as the base body  42 . For example, the second layer L 2  is formed of polyethylene terephthalate (PET), and is bonded to the first layer L 1  through the adhesive layer L 0 . The sealing body  44  is arranged on the first face  42 A of the base body  42  in the state where the first layer L 1  is positioned on the base body  42  side, and is welded to the base body  42  by pressing the sealing body  44  against the first face  42 A from the second layer L 2  side by a jig in the heating state. Since the second layer L 2  is formed of polyethylene terephthalate, it is possible to easily peel off the jig from the surface of the sealing body  44  (second layer L 2 ) after the completion of the welding. On the other hand, the sealing body  46  is formed of single layer of polypropylene in the same manner as the base body  42 , and is welded to the second face  42 B of the base body  42 . The sealing body  46  (second wall portion  462 ) of the first embodiment is transparent. Specifically, transparency of the sealing body  46  is high in comparison with the sealing body  44 . Therefore, there is an advantage that the air bubbles or the foreign materials which are collected by the filter FA or the filter FB may be visually confirmed through the sealing body  46  (in addition to that it is easily possible to determine whether or not an exchange of the filter FA or the filter FB is necessary). Furthermore, a configuration of forming the sealing body  46  by stacking a plurality of layers in the same manner as the illustration of  FIG. 9  or a configuration of forming the sealing body  44  by single layer of polypropylene, for example, may be adopted. 
     Second Embodiment 
     A second embodiment of the invention will be described. In the effects and functions that are similar to the first embodiment in each embodiment which is described hereinafter, the detailed description thereof will be appropriately omitted by using the signs which are used in the description of the first embodiment. 
       FIG. 10  is a configuration diagram which is obtained by focusing on a structure of supporting a plurality of liquid ejecting units  26  among the printing apparatus  10  of the second embodiment. As illustrated in  FIG. 10 , the printing apparatus  10  of the second embodiment includes a liquid ejecting unit  26 A, a liquid ejecting unit  26 B, and a supporting body  80 . Each of the liquid ejecting unit  26 A and the liquid ejecting unit  26 B include the flow channel structure  32  ( 32 A,  32 B), the liquid ejecting head  34  ( 34 A,  34 B), and the wiring circuit board  36  ( 36 A,  36 B), in the same manner as the first embodiment. Therefore, the effects which are similar to the first embodiment are realized in the second embodiment. 
     The supporting body  80  of  FIG. 10  is a structure (frame) that supports the liquid ejecting unit  26 A, and the liquid ejecting unit  26 B, and is manufactured by a bending process with respect to, for example, a flat plate member made of metal. Specifically, the supporting body  80  of the second embodiment includes a main body portion  82 , a fixing portion  84 , and a fixing portion  86 . The main body portion  82  is a flat plate-shaped portion including a first face  82 A, and a second face  82 B which are positioned on the opposite sides to each other. The fixing portion  84 , and the fixing portion  86  are installed on the first face  82 A side of the main body portion  82 . 
     The fixing portion  84  is a flat plate-shaped portion extending over the flow channel structure  32 A of the liquid ejecting unit  26 A and the flow channel structure  32 B of the liquid ejecting unit  26 B, and supports the flow channel structure  32 A, and the flow channel structure  32 B on the first face  82 A side of the main body portion  82  in the state of being arranged at intervals to each other. As illustrated in  FIG. 10 , the flow channel structure  32 A, and the flow channel structure  32 B are supported in the state where each of the sealing bodies  44  face each other at intervals (state where the sealing body  46  is positioned on the opposite side to each other). In other words, the first wall portion  442  of the flow channel structure  32 A of the liquid ejecting unit  26 A, and the first wall portion  442  of the flow channel structure  32 B of the liquid ejecting unit  26 B face each other at intervals. As described above, in the second embodiment, since the liquid ejecting unit  26 A, and the liquid ejecting unit  26 B are installed so that the sealing bodies  44  of the rigidity which is low in comparison with the sealing body  46  face each other, for example, there is an advantage that the sealing body  44  of each flow channel structure  32  may be protected from a collision with an external component, for example, as compared with a configuration where the liquid ejecting unit  26 A, and the liquid ejecting unit  26 B are installed so that the sealing bodies  44  are positioned on the opposite sides to each other. 
     On the other hand, the fixing portion  86  of the supporting body  80  is a flat plate-shaped portion extending over the liquid ejecting head  34 A of the liquid ejecting unit  26 A and the liquid ejecting head  34 B of the liquid ejecting unit  26 B, and supports the liquid ejecting head  34 A, and the liquid ejecting head  34 B in the state of being arranged at intervals to each other. As illustrated in  FIG. 10 , both of the liquid ejecting unit  26 A and the liquid ejecting unit  26 B are supported on the first face  82 A side of the main body portion  82 . 
     The wiring circuit board  36 B of the liquid ejecting unit  26 B which is positioned on the main body portion  82  side when viewed from the liquid ejecting unit  26 A, is inserted into a through hole  83  which is formed in the main body portion  82 , and is extended upwards in a vertical direction along the second face  82 B of the main body portion  82 , and the tip portion thereof is linked to a connection terminal (connector)  88 B on the second face  82 B. On the other hand, the wiring circuit board  36 A of the liquid ejecting unit  26 A which is positioned on the opposite side to the main body portion  82  when viewed from the liquid ejecting unit  26 B, is bent on the face of the first face  82 A of the main body portion  82  by passing through between the flow channel structure  32 A and the liquid ejecting head  34 A of the liquid ejecting unit  26 A, and is extended upwards in the vertical direction along the first face  82 A, and the tip portion thereof is linked to a connection terminal  88 A on the first face  82 A. As understood from the above description, the wiring circuit board  36 A of the liquid ejecting unit  26 A, and the wiring circuit board  36 B of the liquid ejecting unit  26 B are positioned on the opposite sides to each other by interposing the main body portion  82  of the supporting body  80  therebetween. In the above configuration, since the main body portion  82  made of metal which is interposed between the wiring circuit board  36 A and the wiring circuit board  36 B functions as a shield, there is an advantage that a noise with respect to the other from one of the wiring circuit board  36 A and the wiring circuit board  36 B may be reduced. Furthermore, it is possible to use the main body portion  82  in earthing of both of the wiring circuit board  36 A and the wiring circuit board  36 B. 
     Third Embodiment 
     In a third embodiment, the flow channel structure  32  of the first embodiment is replaced with a flow channel structure  90  of  FIG. 11 . The flow channel structure  90  of the third embodiment includes a flow channel p[ 1 ], and a flow channel p[ 2 ] which are independent from each other. Each of the flow channel p[ 1 ] and the flow channel p[ 2 ] are flow channels for supplying the ink which is supplied to the supply flow channel P 1  to the discharge flow channel P 2 , and are independently formed without communicating with each other. 
       FIG. 12  is a diagram for describing each of the flow channel p[ 1 ] and the flow channel p[ 2 ]. As illustrated in  FIG. 12 , each of the flow channel p[ 1 ] and the flow channel p[ 2 ] of the third embodiment, include a flow channel WA, a flow channel WB, a flow channel chamber UA, and a flow channel chamber UB between the supply flow channel P 1  and the discharge flow channel P 2 . The flow channel chamber UA is a space (example of the second flow channel chamber) communicating with each of the supply flow channel P 1  and the flow channel WA by being formed therebetween. A filter F (example of the first filter) that collects the air bubbles or the foreign material from the ink which is supplied to the flow channel chamber UA from the supply flow channel P 1 , is installed in the flow channel chamber UA. 
     The flow channel chamber UB is a space (example of the first flow channel chamber) communicating with each of the flow channel WA and the flow channel WB by being formed therebetween. The adjusting mechanism B is installed between the flow channel chamber UB and the flow channel chamber UA (on the flow channel WA). The adjusting mechanism B of the third embodiment is a valve mechanism that controls the flow and the blocking of the ink of the flow channel WA depending on the pressure (negative pressure) within the flow channel chamber UB, in the same manner as the first embodiment. The ink flowing into the flow channel chamber UB from the flow channel WA is supplied to the flow channel WB in the state where the adjusting mechanism B opens the flow channel WA, and is supplied to the liquid ejecting head  34  from the discharge flow channel P 2  communicating with the flow channel WB. As understood from the above description, in the third embodiment, the flow channel chamber UA and the flow channel chamber UB communicate with each other, and the flow channel chamber UA (second flow channel chamber) is positioned on the upstream side of the flow channel chamber UB (first flow channel chamber). For example, the ink which is pressurized by a pressurizing mechanism (not illustrated) such as a pump, is supplied from the liquid container  14  to the flow channel chamber UA. Therefore, the internal pressure of the flow channel chamber UA is high in comparison with the flow channel chamber UB. For example, the internal pressure of the flow channel chamber UA is maintained at a predetermined value within the range of 30 kPa or more and 40 kPa or less (more preferably, 35±3 [kPa]). 
     As illustrated in  FIG. 11 , the flow channel structure  90  of the third embodiment is a structure where a sealing body  94 [ 1 ] and a sealing body  96 [ 1 ] correlating with the flow channel p[ 1 ], and a sealing body  94 [ 2 ] and a sealing body  96 [ 2 ] correlating with the flow channel p[ 2 ] are joined to a base body  92 . The base body  92  is a structure of a substantially flat plate shape that includes a first face  92 A, and a second face  92 B which are positioned on opposite sides to each other. For example, the base body  92  is formed by the injection molding of a resin material (for example, polypropylene) of light-shielding properties. As illustrated in  FIG. 11 , each supply flow channel P 1  of the channel p[ 1 ] and the channel p[ 2 ] is formed on the upper face of the base body  92 , and each discharge flow channel P 2  of the channel p[ 1 ] and the channel p[ 2 ] is formed on the bottom face of the base body  92 . Furthermore, in the following description, the sealing body  94  is written when the sealing body  94 [ 1 ] and the sealing body  94 [ 2 ] are not necessary to be particularly classified, and the sealing body  96  is written when the sealing body  96 [ 1 ] and the sealing body  96 [ 2 ] are not necessary to be particularly classified. The sealing body  94  is an example of the first sealing body, and the sealing body  96  is an example of the second sealing body. 
     For example, the sealing body  94  and the sealing body  96  are flat plate members of light-transmitting properties which are formed of the resin materials such as polypropylene in the same manner as the base body  92 . The sealing body  94  and the sealing body  96  are different from each other in rigidity (bending rigidity). Specifically, the rigidity of the sealing body  94  is low in comparison with the sealing body  96 , and the sealing body  94  is likely to be deformed. For example, the sealing body  94  is a film of flexibility, and the sealing body  96  is a hard flat plate member of which the plate thickness is greater than that of the sealing body  94 . 
     As understood from  FIG. 11 , the sealing body  96 [ 1 ] of the flow channel p[ 1 ] and the sealing body  94 [ 2 ] of the flow channel p[ 2 ] are fixed to the first face  92 A side of the base body  92 , and the sealing body  94 [ 1 ] of the flow channel p[ 1 ] and the sealing body  96 [ 2 ] of the flow channel p[ 2 ] are fixed to the second face  92 B side of the base body  92 . The sealing body  94 [ 1 ] and the sealing body  96 [ 1 ] face each other by interposing the base body  92  therebetween, and the sealing body  94 [ 2 ] and the sealing body  96 [ 2 ] face each other by interposing the base body  92  therebetween. 
     A plurality of protruding portions  927 A, and a plurality of protruding portions  927 B are formed on each of the first face  92 A and the second face  92 B of the base body  92 . On the other hand, a plurality of protruding engagement portions  947  are formed in the sealing body  94 , and a plurality of protruding engagement portions  967  are formed in the sealing body  96 . The protruding engagement portion  947  is a through hole or a bottomed hole which engages with the protruding portion  927 A, and the protruding engagement portion  967  is a through hole or a bottomed hole which engages with the protruding portion  927 B. A position of a surface direction of the sealing body  94  is determined (positioned) by that each protruding engagement portion  947  of the sealing body  94  engages with the protruding portion  927 A of the base body  92 . Similarly, the position of the surface direction of the sealing body  96  is determined by that each protruding engagement portion  967  of the sealing body  96  engages with the protruding portion  927 B of the base body  92 . 
     As illustrated in  FIG. 11 , a concave portion  921 , a groove portion  922 , and a joining portion  923  are formed in a region which is covered by the sealing body  96 [ 1 ] among the first face  92 A of the base body  92 . The concave portion  921 , and the groove portion  922  are hollow portions which are low in comparison with the first face  92 A. The concave portion  921  communicates with the supply flow channel P 1 , and the end portion of the bottom face side of the base body  92  among the groove portion  922  communicates with the discharge flow channel P 2 . 
     The joining portion  923  is a portion protruding from the first face  92 A. As illustrated in  FIG. 11 , the joining portion  923  of the third embodiment includes a first portion  923 A, and a second portion  923 B. The first portion  923 A is formed into a ring shape which surrounds the concave portion  921  in the planar view, and the second portion  923 B is formed into the ring shape which surrounds the groove portion  922  in the planar view. The first portion  923 A, and the second portion  923 B have the same portion between the concave portion  921  and the groove portion  922 . That is, a portion (partition wall) between the concave portion  921  and the groove portion  922  among the joining portion  923  is shared as the first portion  923 A and the second portion  923 B. Therefore, the area which is necessary for the formation of the joining portion  923  is reduced in comparison with a configuration in which the first portion  923 A, and the second portion  923 B are formed by being separated from each other. As a result, there is an advantage that the flow channel structure  90  may be miniaturized. 
     As illustrated in  FIG. 13 , the sealing body  96 [ 1 ] is joined to a top face of the joining portion  923 . Although a known method may be optionally adopted for joining the sealing body  96 [ 1 ] to the joining portion  923 , a laser welding of joining the sealing body  96 [ 1 ] by irradiating and melting the joining portion  923  with a laser beam L, is suitable. Specifically, as illustrated in  FIG. 13 , the sealing body  96 [ 1 ] is irradiated with the laser beam L from the opposite side to the base body  92  by interposing the sealing body  96 [ 1 ] therebetween. The laser beam L melts the top face facing the sealing body  96 [ 1 ] among the joining portion  923 , by being transmitted through the sealing body  96 [ 1 ] of the light-transmitting properties, and being absorbed with the base body  92  (joining portion  923 ) of the light-shielding properties. The sealing body  96 [ 1 ], and the joining portion  923  are joined by pressing the sealing body  96 [ 1 ] to the joining portion  923  in the above state. 
     As illustrated in  FIG. 11 , a space which is surrounded by the internal face of the concave portion  921  and the facing face (sealing face) of the base body  92  side among the sealing body  96 [ 1 ] functions as the flow channel chamber UA, and a space which is surrounded by the internal face of the groove portion  922  and the sealing face of the sealing body  96 [ 1 ] functions as the flow channel WB. As understood from the above description, the first portion  923 A of the joining portion  923  surrounds the flow channel chamber UA in the planar view, and the second portion  923 B surrounds the flow channel WB in the planar view. The filter F illustrated in  FIG. 12  is installed in the flow channel chamber UA. As understood from  FIG. 11 , the second wall portion  962  which is positioned on the inside of the concave portion  921  among the sealing body  96 [ 1 ] in the planar view, configures the wall face of the flow channel chamber UA, and faces the filter F of the flow channel chamber UA at intervals. 
     As illustrated in  FIG. 11 , the concave portion  924 , and the joining portion  925  are formed in a region which is covered by the sealing body  94 [ 1 ] correlating with the flow channel p[ 1 ] among the second face  92 B of the base body  92 . The concave portion  924  is a hollow portion of the circular shape which is low in comparison with the second face  92 B. The concave portion  924  communicates with the flow channel chamber UA of the first face  92 A side through the flow channel WA (not illustrated in  FIG. 11 ) where the adjusting mechanism B is installed, and communicates with the groove portion  922  (flow channel WB) of the first face  92 A side through a communication hole  926  communicating with the base body  92 . 
     The joining portion  925  is a portion protruding from the second face  92 B. As understood from  FIG. 11 , the joining portion  925  is formed into the ring (annular) shape which surrounds the concave portion  924  in the planar view. As illustrated in  FIG. 14 , the sealing body  94 [ 1 ] is joined to the top face of the joining portion  925 . Although the known method may be optionally adopted for joining the sealing body  94 [ 1 ] to the joining portion  925 , a hot plate welding of joining the sealing body  94 [ 1 ] by melting the joining portion  925  with the pressing of the sealing body  94 [ 1 ] due to a heating face of a jig (hot plate)  200 , is suitable. As understood from  FIG. 13  and  FIG. 14 , a width ω 1  of the joining portion  923  to which the flat plate-shaped sealing body  96 [ 1 ] is joined, is greater than a width ω 2  of the joining portion  925  to which the film-shaped sealing body  94 [ 1 ] is joined. 
     As illustrated in  FIG. 11 , a space which is surrounded by the internal face of the concave portion  924  and the sealing face of the base body  92  side among the sealing body  94 [ 1 ] functions as the flow channel chamber UB. The first wall portion  942  which is positioned on the inside of the concave portion  924  among the sealing body  94 [ 1 ] in the planar view, configures the wall face of the flow channel chamber UB. As understood from the above description, the flow channel p[ 1 ] where the ink flows through a route of the supply flow channel P 1 →the flow channel chamber UA (concave portion  921 )→the flow channel WB→the flow channel chamber UB (concave portion  924 )→the communication hole  926 →the flow channel WB (groove portion  922 )→the discharge flow channel P 2 , is formed. The flow channel chamber UA and the flow channel chamber UB of the flow channel p[ 1 ] overlap with each other in the planar view. 
     The flow channel p[ 2 ] is formed in the same manner as the flow channel p[ 1 ], except for a point of reversing the inside and the outside of the base body  92  to the flow channel p[ 1 ]. Specifically, the concave portion  924 , and the joining portion  925  are formed on the first face  92 A of the base body  92 , and the sealing body  94 [ 2 ] is joined to the joining portion  925 , and a space which is surrounded by the internal face of the concave portion  924  and the sealing face of the sealing body  94 [ 2 ] functions as the flow channel chamber UB. On the other hand, the concave portion  921 , the groove portion  922 , and the joining portion  923  are formed on the second face  92 B of the base body  92 , and the sealing body  96 [ 2 ] is joined to the joining portion  923 . A space which is surrounded by the internal face of the concave portion  921  and the sealing face of the sealing body  96 [ 2 ] functions as the flow channel chamber UA, and a space which is surrounded by the internal face of the groove portion  922  and the sealing face of the sealing body  96 [ 2 ] functions as the flow channel chamber UB. 
       FIG. 15  is a sectional view of the flow channel structure  90  which is obtained by focusing on a relationship between the flow channel chamber UA and the flow channel chamber UB in each of the flow channel p[ 1 ] and the flow channel p[ 2 ]. As illustrated in  FIG. 15 , the flow channel chamber UA, and the flow channel chamber UB communicate with each other through the flow channel WA. The adjusting mechanism B is configured in the same manner as the first embodiment, and is installed between the flow channel WA and the flow channel chamber UB. As illustrated in  FIG. 15 , the adjusting mechanism B of the third embodiment is installed so as to overlap with the flow channel chamber UA and the flow channel chamber UB in the planar view. 
     The pressure plate  76  of the adjusting mechanism B is installed in each first wall portion  942  of the sealing body  94 [ 1 ] and the sealing body  94 [ 2 ]. The valve body  72  of the adjusting mechanism B controls the flow and the blocking of the ink (opening and the closing of the flow channel WA) between the flow channel chamber UA and the flow channel chamber UB in accordance with the deformation of the first wall portion  942 . A specific behavior of the valve body  62  is similar to the first embodiment. That is, for example, if the negative pressure within the flow channel chamber UB is increased due to the ejection of the ink by the liquid ejecting head  34  or the suction from the outside, the flow channel chamber UA, and the flow channel chamber UB communicate with each other by displacing the valve body  72  on the opposite side to the first wall portion  942 . On the other hand, if the negative pressure of the flow channel chamber UB is decreased by the supply of the ink from the flow channel chamber UA, the flow through the flow channel chamber UA and the flow channel chamber UB is blocked, by displacing the valve body  72  on the first wall portion  942  side by the biasing of the spring S 1 . 
     In the state where the adjusting mechanism B blocks the flow channel chamber UA and the flow channel chamber UB, the internal pressure of the flow channel chamber UA is greater than that of the flow channel chamber UB due to the supply of the ink which is pumped from the liquid container  14 . Therefore, there is the possibility that the deformation or the breakage (for example, the peel-off of the sealing body  96 ) of the flow channel chamber UA occurs, in a configuration of forming the sealing body  96  that configures the wall face of the flow channel chamber UA into the film shape which is similar to the sealing body  94  of the flow channel chamber UB. In the third embodiment, since the rigidity of the sealing body  96  configuring the flow channel chamber UA is greater than the rigidity of the sealing body  94  of the flow channel chamber UB, there is an advantage that the possibility of the deformation or the breakage of the flow channel chamber UB may be reduced. Moreover, if the filter F is partially closed by that the sealing body  96  is in contact with the filter F due to the deformation, the problem such as the increase of the pressure loss within the flow channel or the decrease of the foreign material collecting performance by the filter F, may occur. In the third embodiment, since the deformation of the sealing body  96  is suppressed, there is an advantage that the above-described problem which is caused by the contact with the sealing body  96  and the filter F may be suppressed. 
     Various types of configurations which are described in the first embodiment may be also applied to the third embodiment in the same manner. Moreover, various types of configurations which are described in the third embodiment may be also applied to the first embodiment. It is possible to apply the configuration of the second embodiment to the third embodiment (that is, to replace the flow channel structure  32  of  FIG. 10  with the flow channel structure  90  of the third embodiment). 
     Furthermore, a structure for installing the filter F in the flow channel chamber UA is optional, and for example, it is possible to adopt the structure illustrated in  FIG. 16 . In the configuration of  FIG. 16 , the joining portion  923  protruding from the surface (first face  92 A or second face  92 B) of the base body  92 , and an installation portion  928  are formed. The installation portion  928  is formed into the ring shape correlating with an outer shape of the filter F. In the same manner as the third embodiment, for example, the sealing body  96  configuring the flow channel chamber UA is fixed to the joining portion  923  by the laser welding. On the other hand, the filter F of the flow channel chamber UA is fixed to the installation portion  928 . The known method may be optionally adopted for fixing the filter F to the installation portion  928 , but for example, a welding technology such as the hot plate welding or the laser welding is suitable. 
     As illustrated in  FIG. 16 , a groove portion  929  is formed in the region between the joining portion  923  and the installation portion  928  among the surface of the base body  92 . The groove portion  929  is a hollow portion which is low in comparison with the surface of the base body  92 , and is used for the heat radiation in the process of installing the filter F in the installation portion  928 . Specifically, the heat radiating in the vicinity at the time of heating the installation portion  928  radiates in the outside air by the groove portion  929 . Therefore, there is an advantage that the heat deformation (in addition to the decrease of flatness of an installing face of the sealing body  94 ) of the joining portion  923  is suppressed in comparison with a configuration in which the groove portion  929  is not formed. Furthermore, the configuration of  FIG. 16  may be similarly applied to the first embodiment. 
     Modification Example 
     Each embodiment described above may be variously modified. Hereinafter, a specific modified embodiment will be described. The embodiments of two or more which are optionally selected from the following description, may be appropriately combined within the range where the embodiments are not inconsistent with each other. 
     (1) In the first embodiment and the second embodiment, the filter FA of the upstream side and the filter FB of the downstream side of the flow channel chamber RB are described, but one of the filter FA and the filter FB may be omitted. A configuration of omitting the filter F of the third embodiment may be also adopted. Moreover, in each embodiment described above, the flow channel structure  32  is coupled with the liquid ejecting head  34 , but a division flow channel which divides the ink into a plurality of routes or a valve mechanism which controls the pressure of the ink may be installed between the flow channel structure  32  and the liquid ejecting head  34 . 
     (2) In the third embodiment, the position of the surface direction of the sealing body  94  is determined by that the protruding engagement portion  947  of the sealing body  94  engages with the protruding portion  927 A of the base body  92 , and the position of the surface direction of the sealing body  96  is determined by that the protruding engagement portion  967  of the sealing body  96  engages with the protruding portion  927 B of the base body  92 , but the configuration for the positioning of the sealing body  94  and the sealing body  96  is not limited to the above embodiments. 
     For example, as illustrated in  FIG. 17 , the configuration of forming a sealing body engagement portion  948  in the sealing body  94  is assumed. The sealing body engagement portion  948  is an opening of the shape (the substantially circular shape) correlating with the outer shape of the sealing body  96 . In the sealing body  94 , the position of the surface direction is determined by that the protruding engagement portion  947  engages with the protruding portion  927 A of the base body  92  (or other configurations), in the same manner as the third embodiment. On the other hand, in the sealing body  96 , the position of the surface direction is determined by engaging with the sealing body engagement portion  948  of the sealing body  94 . According to the above configuration, there is an advantage that the protruding engagement portion  967  of the sealing body  96  or the protruding portion  927 B of the base body  92  is not necessary. 
     Moreover, as illustrated in  FIG. 18 , it is possible to use the protruding portion  927  which is common in the base body  92  for the positioning of both of the sealing body  94  and the sealing body  96 . In  FIG. 18 , a portion of the sealing body  94  is illustrated by being conveniently broken. As illustrated in  FIG. 18 , the plurality of protruding engagement portions  947  are formed in the sealing body  94 , and the plurality of protruding engagement portions  967  are formed in the sealing body  96 , and both of the protruding engagement portion  947  of the sealing body  94  and the protruding engagement portion  967  of the sealing body  96  engage with each other in each of the plurality of protruding portions  927  which are formed on the surface of the base body  92 . The sealing body  94  and the sealing body  96  partially overlap with each other. According to the configuration of  FIG. 18 , since the common protruding portion  927  is used for the positioning of both of the sealing body  94  and the sealing body  96 , there is an advantage that the protruding portion  927 A for the sealing body  94 , and the protruding portion  927 B for the sealing body  96  are not necessary to be separately formed. 
     (3) In each embodiment described above, a serial head where the carriage  28  in which the plurality of liquid ejecting units  26  are mounted reciprocates in the X direction is described, but a line head where the plurality of liquid ejecting units  26  extending over the total width of the medium  12  in the X direction are arrayed may be applied to the invention. 
     (4) A drive element causing the ink to be ejected from each nozzle N of the liquid ejecting head  34  is not limited to the piezoelectric element which is described in each embodiment described above. For example, it is possible to use a heat generating element (heater) causing the ink to be ejected from the nozzle N by changing the pressure of the pressure chamber in the occurrence of the air bubbles due to the heating as a drive element. The piezoelectric element or the heat generating element is generically expressed as a drive element (specifically, a pressure granting element which changes the pressure of the pressure chamber) causing the liquid to be ejected from the nozzle, and an operating system (piezo system or thermal system) of the drive element or a specific configuration thereof is unmentioned. 
     (5) The printing apparatus  10  which is described in each embodiment described above, may be adopted in various types of devices such as a facsimile apparatus or a copying machine, in addition to a single-purpose device for the printing. However, an application of the liquid ejecting apparatus of the invention is not limited to the printing. For example, a liquid ejecting apparatus which ejects a solution of a color material is used as a manufacturing apparatus which forms a color filter of a liquid crystal display apparatus. Moreover, a liquid ejecting apparatus which ejects a solution of a conductive material is used as a manufacturing apparatus which forms a wiring or an electrode of a wiring circuit board. 
     CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Japanese Patent Application No. 2014-218731 filed on Oct. 27, 2014 and Japanese Patent Application No. 2015-136376 filed on Jul. 7, 2015. The entire disclosures of Japanese Patent Application Nos. 2014-218731 and 2015-136376 are hereby incorporated herein by reference.