Patent Publication Number: US-11040535-B2

Title: Liquid ejecting head and liquid ejecting apparatus

Description:
The present application is based on, and claims priority from JP Application Serial Number 2019-034133, filed Feb. 27, 2019, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a liquid ejecting head and a liquid ejecting apparatus. 
     2. Related Art 
     In the related art, an ink jet recording apparatus including a liquid ejecting head is known (for example, JP-A-2012-143948). In this ink jet recording apparatus, the liquid ejecting head has communication passages, a common liquid chamber as a first common liquid chamber that communicates in common with pressure generating chambers, and a circulation flow channel as a second common liquid chamber. 
     In the liquid ejecting head of the related art, when a pressure change occurs in the liquid in the pressure generating chamber, the liquid may flow into the common liquid chamber and the circulation flow channel from the pressure chamber. In such a case, with the inflow of the liquid, a pressure wave generated in the pressure generating chamber may be propagated to the common liquid chamber and the circulation flow channel, and may be further propagated to another pressure generating chamber that communicates with the common liquid chamber and the circulation flow channel. As described above, when vibration is propagated from one pressure generating chamber to the other pressure generating chamber, crosstalk may occur in which the amount of liquid droplets ejected from the liquid ejecting head becomes unstable. Therefore, in order to reduce the occurrence of crosstalk, it is necessary to improve the compliance of each of the common liquid chamber and the circulation flow channel depending on the amount of the liquid flowing in. The compliance is improved, for example, by increasing the volumes of the common liquid chamber and the circulation flow channel. However, when the volumes of the common liquid chamber and the circulation flow channel increase, the size of the liquid ejecting head may increase. 
     SUMMARY 
     According to an aspect of the present disclosure, a liquid ejecting head is provided. The liquid ejecting head includes: a flow channel forming substrate that forms an individual flow channel including a nozzle and a pressure chamber, a first common liquid chamber, and a second common liquid chamber; and a pressure generating element that causes a pressure change in a liquid in the pressure chamber, in which the first common liquid chamber is coupled to the second common liquid chamber via the individual flow channel, a compliance of the first common liquid chamber is larger than a compliance of the second common liquid chamber, and in the individual flow channel, a flow channel resistance between a first coupling portion with the first common liquid chamber and the pressure chamber is smaller than a flow channel resistance between a second coupling portion with the second common liquid chamber and the pressure chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram schematically illustrating a configuration of a liquid ejecting apparatus according to an embodiment of the present disclosure. 
         FIG. 2  is a schematic sectional view of the liquid ejecting head in an XY plane. 
         FIG. 3  is a schematic sectional view of the liquid ejecting head, which is taken along line III-III of  FIG. 2 . 
         FIG. 4  is an enlarged view of a flow channel structure in an area  4  of  FIG. 3  as indicated by a one-dot chain line. 
         FIG. 5  is a schematic sectional view of the liquid ejecting head in the XY plane. 
         FIG. 6  is a schematic sectional view of the liquid ejecting head, which is taken along line VI-VI of  FIG. 5 . 
         FIG. 7  is an example illustrating a configuration of a liquid ejecting head according to a third embodiment. 
         FIG. 8  is a diagram illustrating an example of a structure of a liquid ejecting head according to a first other embodiment. 
         FIG. 9  is a schematic diagram illustrating an example of a liquid ejecting head according to a second other embodiment. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     A. First Embodiment 
       FIG. 1  is a diagram schematically illustrating a configuration of a liquid ejecting apparatus  100  according to an embodiment of the present disclosure. The liquid ejecting apparatus  100  is an ink jet printing apparatus that ejects an ink, which is an example of a liquid, onto a medium  12 . The liquid ejecting apparatus  100  sets, as the medium  12 , a printing target made of a predetermined material such as a resin film and a cloth in addition to a printing paper sheet, and performs printing by ejecting the liquid onto these various types of media  12 . In an X direction, a Y direction, and a Z direction perpendicular to each other, in each drawing after  FIG. 1 , a main scanning direction that is a movement direction of a liquid ejecting head  26 , which will be described below, is set as the X direction, a sub scanning direction that is a medium feeding direction perpendicular to the main scanning direction is set as the Y direction, and an ink ejecting direction is set as the Z direction. Further, when a direction is specified, a positive direction is set as “+” and a negative direction is set as “−”. In this case, both positive and negative signs are used for direction indication. The liquid ejecting head  26  may not move in the X direction or the liquid ejecting head  26  may move relative to the medium  12  in the Y direction. 
     The liquid ejecting apparatus  100  includes a liquid storage container  14 , a transport mechanism  22  that sends out the medium  12 , a control unit  20 , a head movement mechanism  24 , and the liquid ejecting head  26 . The liquid storage container  14  stores the ink supplied to the liquid ejecting head  26 . A bag-like ink pack formed of a flexible film, an ink tank that can be refilled with the ink or the like can be used as the liquid storage container  14 . The control unit  20  includes a processing circuit such as a central processing unit (CPU) and a storage circuit such as a semiconductor memory, and comprehensively controls the transport mechanism  22 , the head movement mechanism  24 , the liquid ejecting head  26 , and the like. The transport mechanism  22  is operated under a control of the control unit  20 , and sends out the medium  12  in the +Y direction. 
     The head movement mechanism  24  includes a transport belt  23  bridged in the X direction over a printing range of the medium  12  and a carriage  25  in which the liquid ejecting head  26  is stored and which is fixed to the transport belt  23 . The head movement mechanism  24  is operated under the control of the control unit  20 , and causes the carriage  25  to reciprocate in the X direction that is the main scanning direction of the liquid ejecting head  26 . When the carriage  25  reciprocates, the carriage  25  is guided by a guide rail that is not illustrated. The liquid ejecting head  26  has a plurality of nozzles  362  arranged in the Y direction that is the sub scanning direction. A head configuration in which a plurality of the liquid ejecting heads  26  are mounted on the carriage  25  or a head configuration in which the liquid storage container  14  together with the liquid ejecting head  26  is mounted on the carriage  25  may be employed. 
       FIG. 2  is a schematic sectional view of the liquid ejecting head  26  in an XY plane. The liquid ejecting head  26  includes a flow channel formation substrate at which a plurality of individual flow channels  36 , one first common liquid chamber  32 , and one second common liquid chamber  34  are formed. The first common liquid chamber  32  and the second common liquid chamber  34  are coupled to communicate with each other via the plurality of individual flow channels  36 . 
     The liquid storage container  14  and the liquid ejecting head  26  are coupled to each other via a supply flow channel  142  and a recovery flow channel  144  in a state in which the liquid can circulate. The supply flow channel  142  is coupled to a supply port  322  formed in the first common liquid chamber  32  of the liquid ejecting head  26 . The recovery flow channel  144  is coupled to a discharge port  342  formed in the second common liquid chamber  34  of the liquid ejecting head  26 . The recovery flow channel  144  is provided with a pump  146 . The pump  146  sends out the liquid from the liquid ejecting head  26  side to the liquid storage container  14  side, and causes the liquid to circulate between the liquid ejecting head  26  and the liquid storage container  14 . The supply flow channel  142  may be provided with a pump. 
     The liquid in the liquid ejecting head  26  circulates through the following path. The liquid supplied from the liquid storage container  14  via the supply flow channel  142  first flows into the first common liquid chamber  32 . The liquid that has flowed into the first common liquid chamber  32  flows into each of the plurality of individual flow channels  36  coupled to the first common liquid chamber  32 . The liquid that has flowed into the plurality of individual flow channels  36  flows into the second common liquid chamber  34  that is commonly coupled to the plurality of individual flow channels  36 . The liquid in the second common liquid chamber  34  is recovered into the liquid storage container  14  via the recovery flow channel  144 . The liquid recovered in the liquid storage container  14  is supplied to the liquid ejecting head  26  via the supply flow channel  142  again. 
       FIG. 3  is a schematic sectional view of the liquid ejecting head  26 , which is taken along line III-III of  FIG. 2 . As described above, the liquid ejecting head  26  includes, as a flow channel structure, the first common liquid chamber  32 , the second common liquid chamber  34 , and the individual flow channels  36 . In  FIG. 3 , although only one individual flow channel  36  is illustrated, the plurality of individual flow channels  36  are arranged in the Y direction that is a depth direction of the figure. Further, the first common liquid chamber  32  and the second common liquid chamber  34  are commonly coupled to the plurality of individual flow channels  36 . Therefore, the depth of the first common liquid chamber  32  and the second common liquid chamber  34 , the dimension in the Y direction in  FIG. 3 , is larger than the depth of each individual flow channel  36 . Hereinafter, the plurality of individual flow channels  36  arranged in the Y direction are also referred to as an individual flow channel group  36   s.    
     The first common liquid chamber  32  has a larger volume than that of the second common liquid chamber  34 . A first dimension L 1  that is a dimension of the first common liquid chamber  32  in the Z direction is larger than a second dimension L 2  that is a dimension of the second common liquid chamber  34  in the Z direction. In the present embodiment, the first dimension L 1  is equal to or larger than three times the second dimension L 2 . Accordingly, it is easy to increase the volume of the first common liquid chamber  32 . In the present embodiment, the second dimension L 2  is 1 mm or less. 
     Each of the plurality of individual flow channels  36  has the nozzle  362  having an opening for ejecting the liquid and a pressure chamber  364 . A pressure is applied to the liquid in the individual flow channels  36  in the pressure chamber  364 . A part of the liquid to which the pressure is applied is ejected from the nozzle  362 . Further, a part of the liquid that has not been ejected from the nozzle  362  moves to the first common liquid chamber  32  and the second common liquid chamber  34  coupled to the individual flow channels  36 . At this time, vibration generated in the pressure chamber  364  when the pressure is applied propagates, as residual vibration, to the first common liquid chamber  32  and the second common liquid chamber  34  together with inflow of the liquid. Accordingly, residual vibration generated in the individual flow channel  36  by itself is reduced. When the pressure is applied in the pressure chamber  364 , a pressure generating element  70  may be driven to eject the liquid from the nozzle  362  or the pressure generating element  70  may be driven to oscillate the meniscus of the nozzle  362  to the extent that the liquid is not ejected from the nozzle  362 . 
     The individual flow channel  36  has a first coupling portion  324  that is a coupling portion between the individual flow channel  36  and the first common liquid chamber  32  and a second coupling portion  344  that is a coupling portion between the individual flow channel  36  and the second common liquid chamber  34 . The individual flow channel  36  has a first coupling flow channel  366 , the pressure chamber  364 , a second coupling flow channel  368 , and the nozzle  362 . The first coupling flow channel  366  is a flow channel coupling the first coupling portion  324  and the pressure chamber  364  and extending in the Z direction. The second coupling flow channel  368  is configured with a flow channel coupling the second coupling portion  344  and the nozzle  362  and extending in the X direction and a flow channel coupling the nozzle  362  and the pressure chamber  364  and extending in the Z direction. The pressure chamber  364  is a space located between the first coupling flow channel  366  and the second coupling flow channel  368  and is a space provided to correspond to the pressure generating element  70 . 
     The liquid ejecting head  26  includes a first communication plate  42 , a second communication plate  44 , a case  52 , and a pressure chamber forming substrate  46 , as a flow channel forming substrate of a member that forms a flow channel structure. In the liquid ejecting head  26 , the first communication plate  42 , the second communication plate  44 , and the case  52  are stacked in the order thereof from the −Z direction to the +Z direction. Further, the second communication plate  44  and the pressure chamber forming substrate  46  are stacked in the order thereof from the −Z direction to the +Z direction. The first communication plate  42  and the second communication plate  44  are plate-like members extending in the XY plane, respectively. The first communication plate  42  and the second communication plate  44  correspond to a first flow channel substrate  40  formed of the same material. The case  52  corresponds to a second flow channel substrate  50  formed of a material that is different from that of the first flow channel substrate  40 . As the second flow channel substrate  50  and the first flow channel substrate  40  are formed of different materials, for example, the first flow channel substrate  40  can be formed of a silicon single crystal plate that can be processed with high accuracy, and the second flow channel forming member can be formed of a resin molded product that can be molded at low costs. Accordingly, the degree of freedom of design in the liquid ejecting head  26  is improved. The second flow channel substrate  50  and the first flow channel substrate  40  may be formed of the same material. 
     The first communication plate  42  is formed of a silicon single crystal substrate, and has a plurality of opening portions penetrated from one surface on the −Z direction side to the other surface on the +Z direction side. A part of the first common liquid chamber  32 , the second common liquid chamber  34 , and a part of the individual flow channel  36  are formed by the opening portions of the first communication plate  42 , respectively. A first film  62  and a nozzle plate  60  are attached to the opening portion of the first communication plate  42  on the −Z direction side. The first communication plate  42  may be formed of a material other than the silicon single crystal plate, for example, any of various materials such as metal, resin, and glass. 
     The second communication plate  44  is attached to the first communication plate  42  from the −Z direction side via a second film  64 . Similar to the first communication plate  42 , the second communication plate  44  is formed of a silicon single crystal plate, and has a plurality of opening portions penetrated from one surface on the −Z direction side to the other surface on the +Z direction side. Further, the second communication plate  44  has a recess portion  446  that is open on the −Z direction side in addition to the opening portions that form parts of the first common liquid chamber  32  and the individual flow channel  36 . The opening portions formed in the second communication plate  44  are formed with a part of the first common liquid chamber  32  and a part of the individual flow channel group  36   s . The recess portion  446  is formed at a position overlapping the second common liquid chamber  34  formed by the first communication plate  42  in the Z direction. The case  52  and the pressure chamber forming substrate  46  are attached to each other on the +Z direction side of the second communication plate  44 . The second communication plate  44  may be formed of a material other than the silicon single crystal plate, for example, any of various materials such as metal, resin, and glass. 
     The first film  62  is attached to the first communication plate  42  from the −Z direction side to cover the opening portion that forms the first common liquid chamber  32  among the opening portions of the first communication plate  42 . The first film  62  is a film member formed of a flexible resin. The first film  62  may be made of a material other than resin, for example, any of various materials such as thin film metal. 
     The nozzle plate  60  is attached to the first communication plate  42  from the −Z direction side to cover the opening portion that forms the second common liquid chamber  34  and the opening portion that forms the individual flow channel group  36   s  among the opening portions of the first communication plate  42 . The nozzle plate  60  is a plate-like member formed of a silicon single crystal plate and having rigidity. The nozzle plate  60  has a nozzle opening at a position that overlaps each of the individual flow channels  36  defined by the first communication plate  42  in the Z direction. The nozzle  362  is formed in each of the plurality of individual flow channels  36  by the nozzle opening. The nozzle plate  60  may be formed of a material other than the silicon single crystal plate, for example, any of various materials such as metal, resin, and glass. 
     Similar to the first film  62 , the second film  64  is a flexible film member. The second film  64  has openings at a position overlapping the first common liquid chamber  32  and a position overlapping each of the plurality of individual flow channels  36 . Accordingly, the openings formed in the first communication plate  42  and the second communication plate  44  communicate with each other. The second film  64  may be made of a material other than resin, for example, any of various materials such as thin film metal. 
     The second film  64  does not have an opening between the second common liquid chamber  34  defined by the first communication plate  42  and the recess portion  446  formed in the second communication plate  44 . Therefore, the second film  64  partitions the second common liquid chamber  34  and the recess portion  446  in a state in which the second common liquid chamber  34  and the recess portion  446  do not communicate with each other. 
     The case  52 , which is a second flow channel forming member, is formed of a resin molded product such as plastic, which is unlike the first communication plate  42  and the second communication plate  44 . The case  52  has a recess portion at a position overlapping, in the Z direction, the opening that forms a part of the first common liquid chamber  32  among the opening portions formed in the first communication plate  42  and the second communication plate  44 . The recess portion formed in the case  52  is open on the −Z direction side to which the second communication plate  44  is coupled. Further, except for the supply port  322 , the +Z direction side is closed. The case  52  forms the first common liquid chamber  32  together with the first communication plate  42  and the second communication plate  44 . The supply port  322  is formed at a surface of the recess portion of the case  52  on the +Z direction side. The case  52  may be formed of a material other than plastic, for example, any of various materials such as a silicon single crystal plate and metal. 
     The pressure chamber forming substrate  46  is formed of a silicon single crystal plate. The pressure chamber forming substrate  46  has a plurality of recess portions at positions overlapping, in the Z direction, the openings that form some of the plurality of individual flow channels  36  among the opening portions formed in the first communication plate  42  and the second communication plate  44 . The recess portion formed in the pressure chamber forming substrate  46  is open on the −Z direction side to which the second communication plate  44  is coupled, and is closed on the +Z direction side. Each of the plurality of recess portions of the pressure chamber forming substrate  46  forms the pressure chamber  364  in the individual flow channel  36 . The pressure chamber forming substrate  46  may be formed of a material other than the silicon single crystal plate, for example, any of various materials such as metal, resin, and glass. 
     The pressure generating element  70  for causing a pressure change in the liquid in the pressure chamber  364  is disposed on the +Z direction side of the pressure chamber forming substrate  46  while being covered with a protective substrate  48 . That is, a space in which a pressure change is generated by driving the pressure generating element  70  becomes the pressure chamber  364 . In the present embodiment, a piezoelectric element is used as the pressure generating element  70 . The pressure generating element  70  is electrically coupled to an electrode  72 . The electrode  72  is electrically coupled to a flexible cable, a bump, or the like that is not illustrated. In the present embodiment, the liquid ejecting apparatus  100  is a piezo ink jet printer in which a piezoelectric actuator that is a piezoelectric element is employed as a pressure generating element. However, the present disclosure is not limited thereto. For example, the liquid ejecting apparatus  100  may be a thermal ink jet printer that includes, instead of the piezoelectric element, the pressure generating element that changes the pressure in the pressure chamber  364  by heating the liquid in the pressure chamber  364 . 
     The electrode  72  is disposed at a position overlapping the second common liquid chamber  34  in the Z direction. Accordingly, as compared with a case where the electrode  72  is arranged in a position overlapping the first common liquid chamber  32  in the Z direction, the dimension of the first common liquid chamber  32  in the Z direction easily increases. Further, as the electrode  72  is disposed on the +Z direction side of the second common liquid chamber  34  having a relatively small dimension in the Z direction, the liquid ejecting head  26  is easily downsized in the Z direction. 
     As described above, the first common liquid chamber  32  is formed with the first communication plate  42  and the second communication plate  44  that are the first flow channel substrate  40  and the case  52  that is the second flow channel substrate  50 . Further, the bottom surface of the first common liquid chamber  32  is defined by the flexible first film  62 . Accordingly, the compliance of the first common liquid chamber  32  is improved. Further, since a part of the first common liquid chamber  32  is defined by the case  52  formed of plastic, costs for increasing the volume of the first common liquid chamber  32  are reduced. Further, a portion of the first common liquid chamber  32 , which has the first coupling portion  324  with the individual flow channel  36 , is formed with the second communication plate  44  formed of a silicon single crystal plate that can be processed with high accuracy. Therefore, for example, the opening area of the first coupling portion  324  can be adjusted with high accuracy during a manufacturing process. 
     The second common liquid chamber  34  is formed with the first communication plate  42  that is the first flow channel substrate  40 . The bottom surface of the second common liquid chamber  34  is defined by the nozzle plate  60 . The top surface of the second common liquid chamber  34  is defined by the second film  64 . 
     The recess portion  446  is formed at an opposite side of the second common liquid chamber  34  with the second film  64  in between. Therefore, an area of the second film  64 , which defines the top surface of the second common liquid chamber  34 , can be deformed in the Z direction. Accordingly, the compliance of the second common liquid chamber  34  is improved. 
     The second common liquid chamber  34  is formed with the first communication plate  42  formed of a silicon single crystal plate that can be processed with high accuracy. Therefore, for example, the size of the second common liquid chamber  34  can be adjusted with high accuracy during a manufacturing process. Further, for example, the opening area of the second coupling portion  344  can be adjusted with high accuracy. 
     The individual flow channel group  36   s  is formed with the first communication plate  42  and the second communication plate  44  that are the first flow channel substrate  40  and the pressure chamber forming substrate  46 . In detail, the second coupling flow channel  368  extending from the first coupling portion  324  toward the pressure chamber  364  and the first coupling flow channel  366  extending from the second coupling portion  344  toward the pressure chamber  364  in the individual flow channel  36  are formed with the first flow channel substrate  40 . Further, the pressure chamber  364  in the individual flow channel  36  is formed with the pressure chamber forming substrate  46 . The individual flow channel  36  is formed with the first flow channel substrate  40  and the pressure chamber forming substrate  46  formed of a silicon single crystal plate that can be processed with high accuracy. Therefore, for example, the flow channel shape of the individual flow channel  36  can be adjusted with high accuracy during a manufacturing process. 
     The nozzle plate  60  defines the nozzle surface  61  of the liquid ejecting head  26 . The nozzle surface  61  is a wall surface that is opposite to the bottom surface of the second common liquid chamber  34  in the nozzle plate  60 . Further, the nozzle surface  61  is a wall surface on which the nozzle  362  is formed at the outer wall surface of the liquid ejecting head  26 . In the present embodiment, the nozzle surface  61  extends along a direction perpendicular to the Z direction, that is, the XY plane. 
     The first common liquid chamber  32  has an internal space extending both on the +Z direction side from the pressure generating element  70  and on the −Z direction side from the pressure generating element  70 . On the other hand, the second common liquid chamber  34  has an internal space extending only on the −Z direction side from the pressure generating element  70 . Therefore, it is easy to increase the volume of the first common liquid chamber  32 . 
     The first common liquid chamber  32  and the second common liquid chamber  34  communicating with the individual flow channel group  36   s  are configured to have the compliance that can reduce the occurrence of crosstalk. The crosstalk refers to a phenomenon in which vibration generated from the pressure generating element  70  attached to one individual flow channel  36  among the plurality of individual flow channels  36  affects other individual flow channels  36 . With the above configuration, even when the vibration is propagated to the first common liquid chamber  32  and the second common liquid chamber  34  together with the inflow of the liquid from the individual flow channels  36 , the first common liquid chamber  32  and the second common liquid chamber  34  can reduce residual vibration. Therefore, further propagation of the residual vibration propagated to the first common liquid chamber  32  from the first common liquid chamber  32  side to the individual flow channels  36  can be reduced. Therefore, further propagation of the residual vibration propagated to the second common liquid chamber  34  from the second common liquid chamber  34  side to the individual flow channels  36  can be reduced. 
     The compliance capabilities of the first common liquid chamber  32  and the second common liquid chamber  34  are changed depending on the volume of the liquid, the propagation speed of a sound wave in the liquid, the tensile force of the first film  62  or the second film  64 , and the area of the first film  62  or the second film  64 . For example, as the volume of the liquid becomes larger, the compliance becomes larger. Further, the compliance becomes larger as the flexible wall surface of the common liquid chamber, that is, the area of the first film  62  or the second film  64 , becomes larger. Here, the first common liquid chamber  32  has a volume that is larger than that of the second common liquid chamber  34 . Further, the first film  62  has an area that is larger than the second film  64 . Accordingly, the compliance of the first common liquid chamber  32  is larger than the compliance of the second common liquid chamber  34 . In this case, it is preferable that the compliance of the first common liquid chamber  32  is larger than 1.5 times the compliance of the second common liquid chamber  34 , and it is more preferable that the compliance of the first common liquid chamber  32  is larger than 2 times the compliance of the second common liquid chamber  34 . Therefore, even when a larger amount of the liquid flows in the first common liquid chamber  32  than in the second common liquid chamber  34 , the residual vibration can be further reduced, so that the occurrence of the crosstalk can be reduced. 
     As the compliance of the first common liquid chamber  32  is larger than the compliance of the second common liquid chamber  34  as described above, the occurrence of crosstalk can be reduced even when a large amount of the liquid flows into the first common liquid chamber  32 . Thus, in the present embodiment, the plurality of individual flow channels  36  are configured such that the flow channel resistance of the first coupling flow channel  366  between the first coupling portion  324  and the pressure chamber  364  becomes smaller than the flow channel resistance of the second coupling flow channel  368  between the second coupling portion  344  and the pressure chamber  364 . Therefore, when a pressure change in the liquid in the pressure chamber  364  occurs, a large amount of the liquid can flows into the first common liquid chamber  32  having a relatively large compliance. Further, a possibility that the amount of the liquid exceeding the compliance flows into the second common liquid chamber  34  having a relatively small compliance can be reduced. The flow channel resistance depends on a flow channel structure such as a flow channel length and a flow channel cross-section. The magnitude of the flow channel resistance can be compared using the pressure loss in the liquid. For example, in the case of a linear flow channel having the same flow channel cross-section, as the flow channel length of the first coupling flow channel  366  is made shorter than the flow channel length of the second coupling flow channel  368 , the magnitude relationship between the flow channel resistances described above is generated. 
     Further, in the plurality of individual flow channels  36 , the inertance between the first coupling portion  324  and the pressure chamber  364 , that is, of the first coupling flow channel  366 , is smaller than the inertance between the second coupling portion  344  and the pressure chamber  364 , that is, of the second coupling flow channel  368 . The inertance is a parameter that determines easiness of instantaneous flow of the liquid. That is, although the easiness of movement of the liquid in the flow channel is described and is expressed as mass in the laws of motion, the equivalent mass when the easiness of movement of the liquid in the flow channel is applied to flow in a pipeline is the inertance. When a pressure change in the liquid in the pressure chamber  364  occurs, a large amount of the liquid can flows into the first common liquid chamber  32  having a relatively large compliance. Further, a possibility that the amount of the liquid exceeding the compliance flows into the second common liquid chamber  34  having a relatively small compliance can be reduced. The inertance depends on a flow channel structure such as a flow channel length and a flow channel cross-section. 
       FIG. 4  is an enlarged view of a flow channel structure in an area  4  of  FIG. 3  as indicated by a one-dot chain line. The second coupling flow channel  368  in the individual flow channel  36  is provided with a partition wall  426  that reduces the flow channel cross-sectional area of the individual flow channel  36 . The partition wall  426  is provided on the second coupling portion  344  side from the nozzle  362  among the second coupling flow channel  368 . In more detail, the partition wall  426  is provided between a branching point  369  and the second coupling portion  344 . The branching point  369  is a position where a flow channel extending from the nozzle  362  toward the pressure chamber  364  and a flow channel extending from the nozzle  362  toward the second common liquid chamber  34  are branched in the individual flow channel  36 . That is, the individual flow channel  36  branches off to the second coupling portion  344  and the nozzle  362  at the branching point  369  between the pressure chamber  364  and the second coupling portion  344 . 
     As the partition wall  426  is provided in the individual flow channel  36 , the inertance from the branching point  369  to the second coupling portion  344  increases. Further, the inertance of the first coupling flow channel  366  is smaller than the inertance of the second coupling flow channel  368  provided with the partition wall  426  on the second coupling portion  344  side from the branching point  369 . Accordingly, the inertance of the first coupling flow channel  366  is larger than the inertance of the second coupling flow channel  368  without increasing the inertance from the pressure chamber  364  to the nozzle  362 . Therefore, the liquid can smoothly move from the pressure chamber  364  to the nozzle  362 , so that the liquid can be efficiently ejected from the nozzle  362  based on the pressure change generated by the pressure generating element  70 . That is, liquid ejection efficiency of the liquid ejecting head  26  is improved. Further, the inertance between the first coupling portion  324  and the pressure chamber  364  is smaller than the inertance between the second coupling portion  344  and the branching point  369  with the nozzle  362 . Accordingly, propagation of the residual vibration from the second common liquid chamber  34  to the nozzle  362  is reduced. Therefore, since the residual vibration propagated from the second common liquid chamber  34  to the nozzle  362  is quickly attenuated, in the liquid ejecting head  26 , the occurrence of crosstalk can be reduced even when an ejection frequency of the liquid ejecting head  26  is reduced. 
     Further, the flow channel resistance between the first coupling portion  324  and the pressure chamber  364  is smaller than the flow channel resistance between the second coupling portion  344  and the branching point  369  with the nozzle  362 . Accordingly, the flow channel resistance of the first coupling flow channel  366  can be made smaller than the flow channel resistance of the second coupling flow channel  368  without increasing the flow channel resistance between the pressure chamber  364  and the nozzle  362 . Accordingly, the liquid can smoothly move from the pressure chamber  364  to the nozzle  362 , so that the liquid ejection efficiency of the liquid ejecting head  26  is improved. 
     According to the liquid ejecting head  26  of the first embodiment as described above, the compliance of the first common liquid chamber  32  is larger than the compliance of the second common liquid chamber  34 , and the flow channel resistance between the first coupling portion  324  and the pressure chamber  364  is smaller than the flow channel resistance between the second coupling portion  344  and the pressure chamber  364 . Therefore, in the liquid ejecting head  26 , when the pressure of the liquid in the pressure chamber  364  changes, vibration by a pressure wave from the pressure chamber  364  toward the first common liquid chamber  32  can be absorbed by the compliance of the first common liquid chamber  32 . Therefore, in the liquid ejecting head  26 , the occurrence of crosstalk caused as the residual vibration remaining after being propagated to the first common liquid chamber  32  side moves toward the individual flow channel  36  can be reduced. Further, the flow channel resistance of the second coupling flow channel  368  coupled to the second common liquid chamber  34  having a relatively small compliance is relatively large, so that a possibility of inflow of the amount of the liquid exceeding the compliance can be reduced. Accordingly, the occurrence of crosstalk caused as the residual vibration remaining after being propagated to the second common liquid chamber  34  side moves toward the individual flow channel  36  is reduced without increasing the compliance of the second common liquid chamber  34 , so that an increase in the size of the second common liquid chamber  34  required when the compliance of the second common liquid chamber  34  increases can be suppressed. Therefore, the liquid ejecting head  26  can be easily downsized. 
     Further, according to the above-described first embodiment, since the inertance between the first coupling portion  324  and the pressure chamber  364  is smaller than the inertance between the second coupling portion  344  and the pressure chamber  364 , the liquid in the individual flow channel  36  flows more easily in the first common liquid chamber  32  than in the second common liquid chamber  34 . Therefore, the liquid ejecting head  26  can be more easily downsized. 
     B. Second Embodiment 
       FIG. 5  is a schematic sectional view of the liquid ejecting head  26  in the XY plane. The liquid ejecting head  226  is different from that according to the first embodiment in that the liquid ejecting head  226  includes two first common liquid chambers  32 A and  32 B and one second common liquid chamber  34 . The two first common liquid chambers  32 A and  32 B are coupled to the second common liquid chamber  34  through different individual flow channels  36 A and  36 B, respectively. Therefore, the liquid ejecting head  226  has, in the X direction that is a main scanning direction, two nozzle rows having the plurality of nozzles  362  arranged in the Y direction that is a sub scanning direction. Hereinafter, the same components as those according to the first embodiment are designated by the same reference numerals as those according to the first embodiment, and detailed description thereof will be omitted. 
     The liquid in the liquid ejecting head  226  circulates through the following path. The liquid supplied from the liquid storage container  14  flows into the one first common liquid chamber  32 A via one supply flow channel  142 A among two supply flow channels  142 A and  142 B and flows into the other first common liquid chamber  32 B via the other supply flow channel  142 B among the two supply flow channels  142 A and  142 B. The liquid that has flowed into the first common liquid chambers  32 A and  32 B flows into each of the plurality of different individual flow channels  36  coupled to the two first common liquid chambers  32 A and  32 B. The liquid that has flowed into the plurality of individual flow channels  36  flows into the second common liquid chamber  34  that is commonly coupled to the entire individual flow channels  36 . The liquid in the second common liquid chamber  34  is recovered into the liquid storage container  14  via the recovery flow channel  144 . The liquid recovered in the liquid storage container  14  is supplied to the liquid ejecting head  226  via the two supply flow channels  142 A and  142 B again. 
       FIG. 6  is a schematic sectional view of the liquid ejecting head  226 , which is taken along line VI-VI of  FIG. 5 . Even in the present embodiment, the electrode  72  electrically coupled to the pressure generating element  70  is disposed at a position overlapping the second common liquid chamber  34  in the Z direction. Hereinafter, the plurality of individual flow channels  36 A coupling the one first common liquid chamber  32 A and the second common liquid chamber  34  are referred to as an individual flow channel group  36 As, and the plurality of individual flow channels  36 B coupling the one first common liquid chamber  32 B and the second common liquid chamber  34  are referred to as an individual flow channel group  36 Bs. In the present embodiment, the numbers of the individual flow channels  36 A and  36 B respectively included in the one individual flow channel group  36 As and the other individual flow channel group  36 Bs are the same. However, the numbers of the individual flow channels  36 A and  36 B may be different from each other. 
     When the pressure of the liquid simultaneously changes in the pressure chamber  364  of each of the individual flow channel groups  36 As and  36 Bs, the vibration is propagated to the first common liquid chambers  32 A and  32 B from the individual flow channel groups  36 As and  36 Bs coupled to the first common liquid chambers  32 A and  32 B, respectively. On the other hand, the vibration is propagated from the coupled individual flow channel groups  36 As and  36 Bs to the second common liquid chamber  34 . Therefore, the number of the pressure chambers  364  that are generation sources of the vibration propagated to the second common liquid chamber  34  is twice the number of the pressure chambers  364  that are generation sources of the vibration propagated to the first common liquid chambers  32 A and  32 B. Therefore, in the liquid ejecting head  226 , it is necessary to set the compliance in consideration of a ratio of the number of the individual flow channels  36  coupled to each of the first common liquid chamber  32 A and  32 B to the number of the individual flow channels  36  coupled to the second common liquid chamber  34 . 
     The compliance of each of the first common liquid chambers  32 A and  32 B is larger than a half of the compliance of the second common liquid chamber  34 . In this case, it is preferable that the compliance of the first common liquid chamber  32  is larger than 1.5 times a half of the compliance of the second common liquid chamber  34 , and it is more preferable that the compliance of the first common liquid chamber  32  is larger than 2 times a half of the compliance of the second common liquid chamber  34 . Therefore, even when a larger amount of the liquid flows in the first common liquid chamber  32  than in the second common liquid chamber  34 , the occurrence of crosstalk can be reduced. Therefore, even when the sum of the amounts of the liquids flowing into the two first common liquid chambers  32 A and  32 B is larger than the amount of the liquid flowing into the second common liquid chamber  34 , the occurrence of crosstalk can be reduced. 
     In the individual flow channel group  36 As, the flow channel resistance of the first coupling flow channel  366  between the first coupling portion  324 A in the first common liquid chamber  32 A and the pressure chamber  364  is smaller than the flow channel resistance of the second coupling flow channel  368  between the second coupling portion  344  and the pressure chamber  364 . Similarly, in the individual flow channel group  36 Bs, the flow channel resistance of the first coupling flow channel  366  between the first coupling portion  324 B in the first common liquid chamber  32 B and the pressure chamber  364  is smaller than the flow channel resistance of the second coupling flow channel  368  between the second coupling portion  344  and the pressure chamber  364 . Further, the inertance of the first coupling flow channel  366  in the individual flow channel group  36 As is smaller than the inertance of the second coupling flow channel  368 , and the inertance of the first coupling flow channel  366  in the individual flow channel group  36 Bs is smaller than the inertance of the second coupling flow channel  368 . Further, in the individual flow channel group  36 As, the inertance between the first coupling portion  324 A and the pressure chamber  364  is smaller than the inertance between the second coupling portion  344  and the branching point  369  with the nozzle  362 . In the individual flow channel group  36 Bs, the inertance between the first coupling portion  324 B and the pressure chamber  364  is smaller than the inertance between the second coupling portion  344  and the branching point  369  with the nozzle  362 . Accordingly, the flow channel resistance of the first coupling flow channel  366  can be made larger than the flow channel resistance of the second coupling flow channel  368  without increasing the inertance between the pressure chamber  364  and the nozzle  362 . Accordingly, the liquid can smoothly move from the pressure chamber  364  to the nozzle  362 , so that liquid ejection efficiency in the liquid ejecting head  226  is improved. 
     The liquid ejecting head  226  of the second embodiment described above has the same configuration as that of the first embodiment, so that the same effect is achieved. Further, according to the liquid ejecting head  226  of the second embodiment, the compliance of each of the first common liquid chambers  32 A and  32 B is larger than a half of the compliance of the second common liquid chamber  34 . Further, in the individual flow channel groups  36 As and  36 Bs between the first common liquid chambers  32 A and  32 B and the second common liquid chamber  34 , the flow channel resistance between the first coupling portions  324 A and  324 B and the pressure chamber  364  is smaller than the flow channel resistance between the second coupling portion  344  and the pressure chamber  364 . Therefore, in the liquid ejecting head  226 , when the pressure of the liquid in the pressure chamber  364  changes, vibration by a pressure wave from the pressure chamber  364  toward the first common liquid chambers  32 A and  32 B can be absorbed by the compliance of the first common liquid chambers  32 A and  32 B. Therefore, in the liquid ejecting head  226 , the occurrence of crosstalk caused as the residual vibration remaining after being propagated to the first common liquid chambers  32 A and  32 B side moves toward the individual flow channel  36  can be reduced. Further, the flow channel resistance of the second coupling flow channel  368  coupled to the second common liquid chamber  34  having a relatively small compliance is relatively large, so that a possibility of inflow of the amount of the liquid exceeding the compliance can be reduced. Accordingly, the occurrence of crosstalk caused as the residual vibration remaining after being propagated to the second common liquid chamber  34  side moves toward the individual flow channel  36  is reduced without increasing the compliance of the second common liquid chamber  34 , so that an increase in the size of the second common liquid chamber  34  required when the compliance of the second common liquid chamber  34  increases can be suppressed. Therefore, the liquid ejecting head  26  can be easily downsized. 
     Further, according to the above-described second embodiment, the electrode  72  electrically coupled to the pressure generating element  70  is disposed at a position overlapping the second common liquid chamber  34  in the Z direction. Here, the second common liquid chamber  34  has a relatively small compliance, and has the second dimension L 2  that is smaller than the first dimension L 1 . Therefore, as compared to a case where the electrode  72  is disposed at a position overlapping the first common liquid chamber  32  in the Z direction, the dimension of the entire liquid ejecting head  226  in the Z direction is easily downsized. Further, in the liquid ejecting head  226  having a plurality of rows of the nozzles  362  in the X direction, as compared to a case where the electrode  72  is disposed at a position not overlapping the first common liquid chamber  32  and the second common liquid chamber  34  in the Z direction, the dimension of the liquid ejecting head  226  in the XY direction is easily downsized. 
     C. Third Embodiment 
       FIG. 7  is an example illustrating a configuration of a liquid ejecting head  326  according to a third embodiment. In the third embodiment, the liquid ejecting head  326  is different from that of the second embodiment in that the liquid ejecting head  326  has M (M is an integer of 1 or more) first common liquid chambers  32  and N (N is an integer of 1 or more) second common liquid chambers  34 . At least one of the plurality of individual flow channels  36  constituting the individual flow channel group  36   s  couples one of the M first common liquid chambers  32  and one of the N second common liquid chambers  34 . Hereinafter, the same configurations as those according to the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In the present embodiment, although the numbers of the individual flow channels  36  included in the plurality of individual flow channel groups  36   s  are the same, the numbers of the individual flow channels  36 A and  36 B may be different from each other. 
     When one of the M first common liquid chambers  32  is set as a representative first common liquid chamber  32 , the representative first common liquid chamber  32  is coupled to each of the n (n is an integer of 1 or more and N or less) second common liquid chambers  34  via different individual flow channels constituting the individual flow channel group  36   s . Further, when one of the n second common liquid chambers  34  coupled to the representative first common liquid chamber  32  is set as a representative second common liquid chamber  34 , the representative second common liquid chamber  34  is coupled to each of the m (m is an integer of 1 or more and M or less) first common liquid chambers  32  including the representative first common liquid chamber  32  via different individual flow channels constituting the individual flow channel group  36   s.    
     When the pressure of the liquid simultaneously changes in the pressure chamber  364  of each of the individual flow channels constituting the individual flow channel group  36   s , the vibration is propagated to each of the first common liquid chambers  32  from the individual flow channel constituting the individual flow channel group  36   s  and coupled to the first common liquid chambers  32 . On the other hand, the vibration is propagated to each of the second common liquid chambers  34  from the individual flow channel constituting the individual flow channel group  36   s  and coupled to the second common liquid chambers  34 . Therefore, the number of the pressure chambers  364  serving as generation sources of the vibration propagated to the representative second common liquid chamber  34  is m/n times the number of the pressure chambers  364  serving as generation sources of the vibration propagated to the representative first common liquid chamber  32 . Therefore, in the liquid ejecting head  226 , it is necessary to set the compliance in consideration of a ratio of the number of the individual flow channels constituting the individual flow channel group  36   s  and respectively coupled to the first common liquid chambers  32  to the number of the individual flow channels constituting the individual flow channel group  36   s  and coupled to the second common liquid chamber  34 . 
     The compliance of the representative first common liquid chamber  32  is larger than n/m times the compliance of the representative second common liquid chamber  34  that is one second common liquid chamber  34  coupled to the representative first common liquid chamber  32 . In this case, it is preferable that the compliance of the first common liquid chamber  32  is larger than 1.5 times n/m times the compliance of the second common liquid chamber  34 , and it is more preferable that the compliance of the first common liquid chamber  32  is larger than 2 times n/m times the compliance of the second common liquid chamber  34 . 
     In this case, the flow channel resistance of the first coupling flow channel  366  in the representative first common liquid chamber  32  is smaller than the flow channel resistance of the second coupling flow channel  368  in the representative second common liquid chamber  34 . Further, the inertance of the first coupling flow channel  366  in the representative first common liquid chamber  32  is smaller than the inertance of the second coupling flow channel  368  in the representative second common liquid chamber  34 . Further, in the individual flow channel group  36   s  coupling the representative first common liquid chamber  32  and the representative second common liquid chamber  34 , the inertance between the first coupling portion  324  and the pressure chamber  364  is smaller than the inertance between the second coupling portion  344  and the branching point  369  with the nozzle  362 . Accordingly, the flow channel resistance of the first coupling flow channel  366  can be made larger than the flow channel resistance of the second coupling flow channel  368  without increasing the inertance between the pressure chamber  364  and the nozzle  362 . Accordingly, the liquid can smoothly move from the pressure chamber  364  to the nozzle  362 , so that liquid ejection efficiency of the liquid ejecting head  326  is improved. 
     Hereinafter, in a state in which specific numbers are applied to M, N, m, and n in the above description, the liquid ejecting head  326  will be described. The illustration in  FIG. 7  is a schematic view of the liquid ejecting head  326  in the case of an example in which M=3 and N=4. 
     The liquid ejecting head  326  illustrated in  FIG. 7  has three first common liquid chambers  32   a  to  32   c  and four second common liquid chambers  34   a  to  34   d . For example, when the first common liquid chamber  32   a  is set as the representative first common liquid chamber, the four second common liquid chambers  34   a  to  34   d  are coupled to the representative first common liquid chamber  32   a . In this case, when the second common liquid chamber  34   a  that is one of the four second common liquid chambers  34   a  to  34   d  coupled to the representative first common liquid chamber  32   a  is set as the representative second common liquid chamber, the representative second common liquid chamber  34   a  is coupled to the three first common liquid chambers  32   a  to  32   c  including the representative first common liquid chamber  32   a.    
     The compliance of the representative first common liquid chamber  32   a  is larger than ¾ times the compliance of the representative second common liquid chamber  34   a . Further, the flow channel resistance between the first coupling portion  324  and the pressure chamber  364  in the representative first common liquid chamber  32   a  is smaller than the flow channel resistance between the second coupling portion  344  and the pressure chamber  364 . In the individual flow channel group  36   s , the inertance between the first coupling portion  324  and the pressure chamber  364  in the representative first common liquid chamber  32  is smaller than the inertance between the second coupling portion  344  and the pressure chamber  364  in the representative second common liquid chamber  34   a . Further, in the individual flow channel group  36   s , the inertance between the first coupling portion  324  and the pressure chamber  364  in the representative first common liquid chamber  32  is smaller than the inertance between the second coupling portion  344  and the branching point  369  with the nozzle  362 . 
     Further, for example, when the first common liquid chamber  32   b  is set as the representative first common liquid chamber, the one second common liquid chamber  34   a  is coupled to the representative first common liquid chamber  32   b . In this case, the only one second common liquid chamber  34   b  coupled to the representative first common liquid chamber  32   b  is the representative second common liquid chamber  34   a . The representative second common liquid chamber  34   a  is coupled to the three first common liquid chambers  32   a  to  32   c  including the representative first common liquid chamber  32   b.    
     The compliance of the representative first common liquid chamber  32   b  is larger than 3 times the compliance of the representative second common liquid chamber  34   a . Further, the flow channel resistance between the first coupling portion  324  and the pressure chamber  364  in the representative first common liquid chamber  32   b  is smaller than the flow channel resistance between the second coupling portion  344  and the pressure chamber  364 . In the individual flow channel group  36   s , the inertance between the first coupling portion  324  and the pressure chamber  364  in the representative first common liquid chamber  32   b  is smaller than the inertance between the second coupling portion  344  and the pressure chamber  364  in the representative second common liquid chamber  34   b . Further, in the individual flow channel group  36   s , the inertance between the first coupling portion  324  and the pressure chamber  364  in the representative first common liquid chamber  32   b  is smaller than the inertance between the second coupling portion  344  and the branching point  369  with the nozzle  362 . Accordingly, propagation of the residual vibration from the representative second common liquid chamber  34   a  to the nozzle  362  is reduced. 
     The above-described third embodiment has the same configuration as those of the first embodiment and the second embodiment, so that the same effect is achieved. Further, according to the third embodiment, a relationship between the compliance capabilities of the first common liquid chamber  32  and the second common liquid chamber  34  illustrated in the first embodiment and the second embodiment can be generalized. Accordingly, even when the numbers of the first common liquid chambers  32  and the second common liquid chambers  34  are respectively changed to predetermined numbers, both a reduction in the occurrence of crosstalk and a reduction in the size can be achieved. When M=1 and N=1, the configuration is the same as that of the first embodiment. Further, when M=2 and N=1, the configuration is the same as that of the second embodiment. 
     D. Other Embodiment 
     D1. First Other Embodiment 
     In the above embodiment, the shape and the structure of the first common liquid chamber  32  and the second common liquid chamber  34  can be changed appropriately. For example, although the top surface of the first common liquid chamber  32  extends along the XY plane, the shape of the top surface in the first common liquid chamber  32  is not limited thereto. For example, the shape of the top surface in the first common liquid chamber  32  may have a tapered shape extending in a direction intersecting the XY plane. In this case, the first dimension L 1  that is a dimension of the first common liquid chamber  32  in the Z direction is the maximum distance between the top surface and the bottom surface facing the top surface in the Z direction. Further, in the above embodiment, the supply port  322  is provided on the top surface of the first common liquid chamber  32 . However, the present disclosure is not limited thereto. For example, the supply port  322  may be provided on the side surface of the first common liquid chamber  32 . Further, in the above embodiment, the discharge port  342  is provided on the top surface of the second common liquid chamber  34 . However, the present disclosure is not limited thereto. For example, the first coupling portion  324  may be provided on the side surface of the second common liquid chamber  34 . 
     Further, for example, although the compliance of the first common liquid chamber  32  is secured by the first film  62  that defines the bottom surface, the present disclosure is not limited thereto. Further, for example, although the compliance of the second common liquid chamber  34  is secured by the second film  64  that defines the top surface, the present disclosure is not limited thereto. For example, the first film  62  may be provided on the top surface or the side surface of the first common liquid chamber  32 , and the second film  64  may be provided on the bottom surface or the side surface of the second common liquid chamber  34 . Further, the compliance capabilities of the first common liquid chamber  32  and the second common liquid chamber  34  may be secured using a member other than the first film  62  and the second film  64 . 
       FIG. 8  is a diagram illustrating an example of a structure of a liquid ejecting head  26 A according to a first other embodiment. As the second common liquid chamber  34  is easily downsized, the shape of the second common liquid chamber  34  is easily changed. Therefore, for example, as illustrated in  FIG. 7 , the shape of the second common liquid chamber  34 , specifically, the shape of a top surface Ts of the second common liquid chamber  34  may be an arch shape partially having a tapered shape. In this case, the wall surface defining the second common liquid chamber  34  can be thickened, so that the rigidity of the liquid ejecting head  26 A can be improved. Further, in the liquid ejecting head  26 A, a dimension L 2 A of the second common liquid chamber  34  in the Z direction is the maximum distance between the top surface Ts and a bottom surface Bs facing the top surface Ts in the Z direction. Further, as illustrated in  FIG. 8 , the compliance of the second common liquid chamber  34  may be secured by using the nozzle plate  60 . That is, as the thickness of a portion of the nozzle plate  60 , which covers an opening portion forming the second common liquid chamber  34 , in the Z direction is made thinner than the thickness of the other portion of the nozzle plate  60 , the residual vibration of the second common liquid chamber  34  may be absorbed. 
     D2. Second Other Embodiment 
     In the above embodiment, one first common liquid chamber  32  and one second common liquid chamber  34  are coupled to each other by one individual flow channel  36 . However, the numbers of the first common liquid chamber  32  and the second common liquid chamber  34  coupled to each other by the one individual flow channel  36  are not limited thereto. For example, the number of at least one of the first common liquid chamber  32  and the second common liquid chamber  34  coupled to each other by the one individual flow channel  36  may be two or more. 
       FIG. 9  is a schematic view illustrating an example of a liquid ejecting head  26 B according to a second other embodiment. In the example illustrated in  FIG. 9 , a state in which two second common liquid chambers  34  are coupled to the one individual flow channel  36  is illustrated. In this case, when the number of the first common liquid chamber  32  coupled to the one individual flow channel  36  is one, it is preferable that the compliance of the first common liquid chamber  32  is larger than two times the compliance of the two second common liquid chambers  34  coupled to the first common liquid chamber  32 . In this case, it is preferable that the compliance of the first common liquid chamber  32  is larger than 1.5 times 2 times the compliance of the second common liquid chamber  34 , and it is more preferable that the compliance of the first common liquid chamber  32  is larger than 2 times 2 times the compliance of the second common liquid chamber  34 . 
     In the example of  FIG. 9 , an area of the nozzle plate  60 , which defines the bottom surface Bs of the second common liquid chamber  34 , is thinned, so that the compliance of the second common liquid chamber  34  is improved. Further, in this case, the liquid ejecting head  26 B may not be provided with the second film  64 . Further, in this case, the first flow channel substrate  40  may include only the first communication plate  42 . 
     D3. Third Other Embodiment 
     The method of improving the compliance capabilities of the first common liquid chamber  32  and the second common liquid chamber  34  is not limited to the above embodiment. For example, the sizes of the openings, for example, the supply port  322  and the discharge port  342 , formed in the first common liquid chamber  32  and the second common liquid chamber  34  increases, so that the compliance capabilities of the first common liquid chamber  32  and the second common liquid chamber  34  may be improved. For example, the flexibility of the nozzle plate  60  is improved by thinning the area of the nozzle plate  60 , which defines the bottom surface of the second common liquid chamber  34 . Accordingly, the compliance of the second common liquid chamber  34  may be improved. Further, for example, a configuration in which the area of the nozzle plate  60 , which defines the bottom surface of the second common liquid chamber  34 , is cut out, and the cutout area is blocked with a film member is changed, so that the compliance of the second common liquid chamber  34  may be improved. 
     D4. Fourth Other Embodiment 
     A relationship between the first dimension L 1  of the first common liquid chamber  32  and the second dimension L 2  of the second common liquid chamber  34  is not limited to the above embodiment, and can be changed as long as the relationship between the compliance capabilities of the first common liquid chamber  32  and the second common liquid chamber  34  is secured. For example, the first dimension L 1  may be less than 3 times the second dimension L 2 . Further, both the first common liquid chamber  32  and the second common liquid chamber  34  may have internal spaces extending both on the nozzle plate  60  from the pressure generating element  70  and on an opposite side to the nozzle plate  60  from the pressure generating element  70 . Further, both the first common liquid chamber  32  and the second common liquid chamber  34  may have only an internal space extending from the pressure generating element  70  to the nozzle plate  60 . Further, the first dimension L 1  may be equal to or smaller than the second dimension. The second dimension L 2  may be equal to or larger than 1 mm. 
     Further, a relationship between the volume of the first common liquid chamber  32  and the volume of the second common liquid chamber  34  is not limited to the above embodiment, and can be changed while the relationship between the compliance capabilities of the first common liquid chamber  32  and the second common liquid chamber  34  is secured. For example, in the first embodiment, when the compliance of the first common liquid chamber  32  is designed to be larger than the compliance of the second common liquid chamber  34  due to a factor other than the volume, the volume of the first common liquid chamber  32  may be equal to or less than the volume of the second common liquid chamber  34 . 
     D5. Fifth Other Embodiment 
     In the above embodiment, the first flow channel substrate  40  and the case  52  that is the second flow channel substrate  50  are made of different materials. However, the first flow channel substrate  40  and the case  52  that is the second flow channel substrate  50  may be made of the same material. In detail, for example, both the first flow channel substrate  40  and the second flow channel substrate  50  may be formed of plastic. Further, for example, both the first flow channel substrate  40  and the second flow channel substrate  50  may be formed of a silicon single crystal plate. 
     D6. Sixth Other Embodiment 
     In the above embodiment, the first common liquid chamber  32  is located upstream of the second common liquid chamber  34  in a liquid circulation path. However, the first common liquid chamber  32  may be located downstream of the second common liquid chamber  34 . Further, the number of the individual flow channel  36  between the first common liquid chamber  32  and the second common liquid chamber  34  may be one. 
     D7. Seventh Other Embodiment 
     In the above embodiment, the inertance between the first coupling portion  324  and the pressure chamber  364  is smaller than the inertance between the second coupling portion  344  and the pressure chamber  364 , and the flow channel resistance between the first coupling portion  324  and the pressure chamber  364  is smaller than the flow channel resistance between the second coupling portion  344  and the pressure chamber  364 . However, the relationships of the inertance and the flow channel resistance can be changed as long as the occurrence of crosstalk can be reduced. For example, at least one of at least the inertance and the flow channel resistance may be smaller than between the first coupling portion  324  and the pressure chamber  364  than between the second coupling portion  344  and the pressure chamber  364 . 
     In the above embodiment, the inertance between the first coupling portion  324  and the pressure chamber  364  is smaller than the inertance between the second coupling portion  344  and the branching point  369 . However, the present disclosure is not limited thereto. For example, the inertance between the first coupling portion  324  and the pressure chamber  364  may be equal to or larger than the inertance between the second coupling portion  344  and the branching point  369 . In this case, the nozzle  362  may not be provided between the second coupling portion  344  and the pressure chamber  364 . In detail, for example, the nozzle  362  may be provided between the first coupling portion  324  and the pressure chamber  364 . 
     D8. Eighth Other Embodiment 
     In the above embodiment, the partition wall  426  is provided in the second coupling flow channel  368 . However, the present disclosure is not limited thereto. For example, the second coupling portion  344  may not include the partition wall  426 . In this case, the second coupling portion  344  has a structure different from that of the partition wall  426 , and thus, the inertance or the flow channel resistance may increase. 
     D9. Ninth Other Embodiment 
     In the above embodiment, the nozzle  362  is provided in the second coupling flow channel  368 . However, the present disclosure is not limited thereto. For example, the nozzle  362  may be provided in the first coupling flow channel  366 . 
     D10. Tenth Other Embodiment 
     In the above embodiment, the first communication plate  42 , the second communication plate  44 , the case  52 , and the pressure chamber forming substrate  46  are provided as a flow channel forming substrate of a member that forms a flow channel structure. However, a combination of the flow channel forming substrate in which the first common liquid chamber  32 , the second common liquid chamber  34 , and the individual flow channel  36  are formed is not limited thereto. For example, the first common liquid chamber  32 , the second common liquid chamber  34 , and the individual flow channel  36  may be formed in one or more of the first communication plate  42 , the second communication plate  44 , the case  52 , and the pressure chamber forming substrate  46 . Further, the first communication plate  42 , the second communication plate  44 , the case  52 , and the pressure chamber forming substrate  46  may be integrally formed by three-dimensional modeling. 
     D11. Eleventh Other Embodiment 
     In the second and third embodiments, each of the individual flow channel groups  36   s  includes the same number of the individual flow channels  36 . However, the present disclosure is not limited thereto. For example, the plurality of individual flow channel groups  36   s  may include different numbers of the individual flow channels  36 . 
     The first to eleventh other embodiments have the same configuration as the above embodiment, so that the same effect is achieved. 
     D12. Twelfth Other Embodiment 
     The present disclosure is not limited to an ink jet printer and an ink tank for supplying an ink to the ink jet printer, and can be applied to a predetermined liquid ejecting apparatus that ejects various liquids including the ink and a liquid tank that stores the liquids. For example, the present disclosure can be applied to the following various liquid ejecting apparatuses and the following liquid storage containers thereof.
     (1) An image recording apparatus such as a facsimile machine,   (2) A color material ejecting apparatus used for manufacturing a color filter for an image display device such as a liquid crystal display,   (3) An electrode material ejecting apparatus used for forming an electrode of an organic electro luminescence (EL) display, a surface light emission display (a field emission display, FED), and the like,   (4) A liquid ejecting apparatus that ejects a liquid containing a bio-organic material used for manufacturing a biochip,   (5) A sample ejecting apparatus as a precision pipette,   (6) A lubricating oil ejecting apparatus,   (7) A resin liquid ejecting apparatus,   (8) A liquid ejecting apparatus that ejects a lubricating oil to a precision machine such as a timepiece and a camera using a pinpoint,   (9) A liquid ejecting apparatus that ejects a transparent resin liquid such as an ultraviolet curable resin liquid onto a substrate in order to form a micro hemispherical lens (optical lens) used for an optical communication element or the like,   (10) A liquid ejecting apparatus that ejects an acidic or alkaline etching solution for etching a substrate or the like, and   (11) A liquid ejecting apparatus including a liquid ejecting head that ejects the small amount of other predetermined liquid droplets.   

     The “liquid droplets” refer to a state of the liquid ejected from the liquid ejecting apparatus, which includes a particle shape, a tear shape, and a shape obtained by pulling a tail in a thread shape. Further, the “liquid” herein may be any material that can be ejected by the liquid ejecting apparatus. For example, the “liquid” may be a material in a state in which a substance is in a liquid phase, and also includes a liquid material such as a material in a liquid state having high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, and liquid metals (metallic melts). Further, the “liquid” includes not only a liquid as one state of a substance but also a liquid in which particles of a functional material made of a solid such as a pigment or metal particles are dissolved, dispersed, or mixed in a solvent. Further, representative examples of the liquid include the ink, the liquid crystal, and the like as described in the above embodiment. Here, the ink includes various liquid compositions such as general water-based ink, oil-based ink, and gel ink. 
     The present disclosure is not limited to the above-described embodiment, and can be realized with various configurations without departing from the spirit of the present disclosure. For example, the technical features of the embodiments corresponding to the technical features in each aspect described in the summary of the present disclosure can be appropriately replaced or combined in order to solve some or the entirety of the above-described problems or achieve some or the entirety of the above-described effects. Further, when the technical features are not described as essential in the present specification, the technical features can be deleted as appropriate. 
     (1) According to an aspect of the present disclosure, a liquid ejecting head is provided. The liquid ejecting head includes: a flow channel forming substrate that forms an individual flow channel including a nozzle and a pressure chamber, a first common liquid chamber, and a second common liquid chamber; and a pressure generating element that causes a pressure change in a liquid in the pressure chamber, in which the first common liquid chamber is coupled to the second common liquid chamber via the individual flow channel, a compliance of the first common liquid chamber is larger than a compliance of the second common liquid chamber, and in the individual flow channel, a flow channel resistance between a first coupling portion with the first common liquid chamber and the pressure chamber is smaller than a flow channel resistance between a second coupling portion with the second common liquid chamber and the pressure chamber. According to the liquid ejecting head of the aspect, the compliance of the first common liquid chamber is larger than the compliance of the second common liquid chamber, and the flow channel resistance between the first coupling portion and the pressure chamber is smaller than the flow channel resistance between the second coupling portion and the pressure chamber. Therefore, in the liquid ejecting head, when the pressure of the liquid in the pressure chamber changes, vibration by a pressure wave from the pressure chamber toward the first common liquid chamber can be absorbed by the compliance of the first common liquid chamber. Therefore, in the liquid ejecting head, the occurrence of crosstalk caused as the residual vibration remaining after being propagated to the first common liquid chamber side moves toward the individual flow channel can be reduced. Further, as the flow channel resistance between the second coupling portion and the pressure chamber is large, inflow of the liquid into the second common liquid chamber can be reduced, so that the occurrence of crosstalk caused as the residual vibration remaining after being propagated to the second common liquid chamber side moves toward the individual flow channel is reduced. Therefore, the liquid ejecting head can be easily downsized. 
     (2) According to another aspect of the present disclosure, a liquid ejecting head is provided. The liquid ejecting head includes: a flow channel forming substrate that forms an individual flow channel including a nozzle and a pressure chamber, a first common liquid chamber, and a second common liquid chamber; and a pressure generating element that causes a pressure change in a liquid in the pressure chamber, in which the first common liquid chamber is coupled to the second common liquid chamber via the individual flow channel, a compliance of the first common liquid chamber is larger than a compliance of the second common liquid chamber, and in the individual flow channel, an inertance between a first coupling portion with the first common liquid chamber and the pressure chamber is smaller than an inertance between a second coupling portion with the second common liquid chamber and the pressure chamber. According to the liquid ejecting head of the aspect, the compliance of the first common liquid chamber is larger than the compliance of the second common liquid chamber, and the inertance between the first coupling portion and the pressure chamber is smaller than the inertance between the second coupling portion and the pressure chamber. Therefore, in the liquid ejecting head, when the pressure of the liquid in the pressure chamber changes, vibration by a pressure wave from the pressure chamber toward the first common liquid chamber can be absorbed by the compliance of the first common liquid chamber. Therefore, in the liquid ejecting head, the occurrence of crosstalk caused as the residual vibration remaining after being propagated to the first common liquid chamber side moves toward the individual flow channel can be reduced. Further, as the inertance between the second coupling portion and the pressure chamber is large, inflow of the liquid into the second common liquid chamber can be reduced, so that the occurrence of crosstalk caused as the residual vibration remaining after being propagated to the second common liquid chamber side moves toward the individual flow channel is reduced. Therefore, the liquid ejecting head can be easily downsized. 
     (3) In the liquid ejecting head of the aspect, in the individual flow channel, the inertance between the first coupling portion and the pressure chamber may be smaller than the inertance between the second coupling portion and the pressure chamber. According to the liquid ejecting head of the aspect, since the inertance between the first coupling portion and the pressure chamber is smaller than the inertance between the second coupling portion and the pressure chamber, the liquid in the individual flow channel is more likely to flow in the first common liquid chamber than in the second common liquid chamber. Therefore, the liquid ejecting head can be more easily downsized. 
     (4) In the liquid ejecting head of the aspect, the individual flow channel may branch off to the second coupling portion and the nozzle at a branching point between the pressure chamber and the second coupling portion, and an inertance between the first coupling portion and the pressure chamber may be smaller than an inertance between the second coupling portion and the branching point in the individual flow channel. According to the liquid ejecting head of the aspect, the inertance between the first coupling portion and the pressure chamber can smaller than the inertance between the second coupling portion and the pressure chamber without increasing an inertance between the pressure chamber and the nozzle. Accordingly, the liquid can smoothly move from the pressure chamber to the nozzle, so that liquid ejection efficiency of the liquid ejecting head is improved. 
     (5) According to yet another aspect of the present disclosure, a liquid ejecting head is provided. The liquid ejecting head includes: a flow channel forming substrate that forms a plurality of individual flow channels each including a nozzle and a pressure chamber, M (M is an integer of 1 or more) first common liquid chambers, and N (N is an integer of 1 or more) second common liquid chambers; and a pressure generating element that causes a pressure change in a liquid in the pressure chamber, in which at least one of the plurality of individual flow channels constitutes an individual flow channel group and couples corresponding one of the M first common liquid chambers and corresponding one of the N second common liquid chambers, a representative first common liquid chamber, which is one of the M first common liquid chambers, is coupled to each of n (n is an integer of 1 or more and N or less) second common liquid chambers among the N second common liquid chambers via corresponding one of the individual flow channels constituting the individual flow channel group, a representative second common liquid chamber, which is one of the n second common liquid chambers, is coupled to each of m (m is an integer of 1 or more and M or less) first common liquid chambers including the representative first common liquid chamber among the M first common liquid chambers via corresponding one of the individual flow channels constituting the individual flow channel group, a compliance of the representative first common liquid chamber is larger than n/m times a compliance of the representative second common liquid chamber, and in the individual flow channel constituting the individual flow channel group between the representative first common liquid chamber and the representative second common liquid chamber, a flow channel resistance between a first coupling portion with the representative first common liquid chamber and the pressure chamber is smaller than a flow channel resistance between a second coupling portion with the representative second common liquid chamber and the pressure chamber. According to the liquid ejecting head of the aspect, the compliance of the representative first common liquid chamber is larger than n/m times the compliance of the representative second common liquid chamber, and in the individual flow channel group between the representative first common liquid chamber and the representative second common liquid chamber, the flow channel resistance between the first coupling portion with the representative first common liquid chamber and the pressure chamber is smaller than the flow channel resistance between the second coupling portion with the representative second common liquid chamber and the pressure chamber. Therefore, in the liquid ejecting head, when the pressure of the liquid in the pressure chamber changes, vibration by a pressure wave from the pressure chamber toward the first common liquid chamber can be absorbed by the compliance of the first common liquid chamber. Therefore, in the liquid ejecting head, the occurrence of crosstalk caused as the residual vibration remaining after being propagated to the first common liquid chamber side moves toward the individual flow channel can be reduced. Further, as the flow channel resistance between the second coupling portion and the pressure chamber is large, inflow of the liquid into the second common liquid chamber can be reduced, so that the occurrence of crosstalk caused as the residual vibration remaining after being propagated to the second common liquid chamber side moves toward the individual flow channel is reduced. Therefore, the liquid ejecting head can be easily downsized. 
     (6) According to yet another aspect of the present disclosure, a liquid ejecting head is provided. The liquid ejecting head includes: a flow channel forming substrate that forms a plurality of individual flow channels each including a nozzle and a pressure chamber, M (M is an integer of 1 or more) first common liquid chambers, and N (N is an integer of 1 or more) second common liquid chambers; and a pressure generating element that causes a pressure change in a liquid in the pressure chamber, in which at least one of the plurality of individual flow channels constitutes an individual flow channel group, and couples at least corresponding one of the M first common liquid chambers and at least corresponding one of the N second common liquid chambers, a representative first common liquid chamber, which is one of the M first common liquid chambers, is coupled to each of n (n is an integer of 1 or more and N or less) second common liquid chambers among the N second common liquid chambers via corresponding one of the individual flow channels constituting the individual flow channel group, a representative second common liquid chamber, which is one of the n second common liquid chambers, is coupled to each of m (m is an integer of 1 or more and M or less) first common liquid chambers including the representative first common liquid chamber among the M first common liquid chambers via corresponding one of the individual flow channels constituting the individual flow channel group, a compliance of the representative first common liquid chamber is larger than n/m times a compliance of the representative second common liquid chamber, and in the individual flow channel constituting the individual flow channel group between the representative first common liquid chamber and the representative second common liquid chamber, an inertance between a first coupling portion with the representative first common liquid chamber and the pressure chamber is smaller than an inertance between a second coupling portion with the representative second common liquid chamber and the pressure chamber. Therefore, in the liquid ejecting head, when the pressure of the liquid in the pressure chamber changes, vibration by a pressure wave from the pressure chamber toward the first common liquid chamber can be absorbed by the compliance of the first common liquid chamber. Therefore, in the liquid ejecting head, the occurrence of crosstalk caused as the residual vibration remaining after being propagated to the first common liquid chamber side moves toward the individual flow channel can be reduced. Further, as the inertance between the second coupling portion and the pressure chamber is large, inflow of the liquid into the second common liquid chamber can be reduced, so that the occurrence of crosstalk caused as the residual vibration remaining after being propagated to the second common liquid chamber side moves toward the individual flow channel is reduced. Therefore, the liquid ejecting head can be easily downsized. 
     (7) According to the liquid ejecting head of the aspect, in the individual flow channel constituting the individual flow channel group between the representative first common liquid chamber and the representative second common liquid chamber, an inertance between the first coupling portion with the representative first common liquid chamber and the pressure chamber may be smaller than an inertance between the second coupling portion with the representative second common liquid chamber and the pressure chamber. According to the liquid ejecting head of the aspect, since the inertance between the first coupling portion and the pressure chamber is smaller than the inertance between the second coupling portion and the pressure chamber, the liquid in the individual flow channel is more likely to flow in the first common liquid chamber than in the second common liquid chamber. Therefore, the liquid ejecting head can be more easily downsized. 
     (8) In the liquid ejecting head of the aspect, the individual flow channel may branch off to the second coupling portion and the nozzle at a branching point between the pressure chamber and the second coupling portion, and in the individual flow channel constituting the individual flow channel group between the representative first common liquid chamber and the representative second common liquid chamber, an inertance between the first coupling portion and the pressure chamber may be smaller than an inertance between the second coupling portion and the branching point in the individual flow channel. According to the liquid ejecting head of the aspect, the inertance between the first coupling portion and the pressure chamber can smaller than the inertance between the second coupling portion and the pressure chamber without increasing an inertance between the pressure chamber and the nozzle. Accordingly, the liquid can smoothly move from the pressure chamber to the nozzle, so that liquid ejection efficiency of the liquid ejecting head is improved. 
     (9) In the liquid ejecting head of the aspect, M is 2, N is 1, m is 2, and n is 1, and an electrode electrically coupled to the pressure generating element may be disposed at a position overlapping the second common liquid chamber in a direction perpendicular to a nozzle surface at which the nozzle is formed. According to the liquid ejecting head of the aspect, it is easy to increase the dimension of the first common liquid chamber in a direction perpendicular to the nozzle surface. Accordingly, it is easy to increase the volume of the first common liquid chamber. However, it is easy to increase the compliance of the first common liquid chamber. 
     (10) In the liquid ejecting head of the aspect, a first dimension that is a dimension of the first common liquid chamber in a direction perpendicular to a nozzle surface at which the nozzle is formed may be larger than a second dimension that is a dimension of the second common liquid chamber in the direction. According to the liquid ejecting head of the aspect, it is easy to increase the volume of the first common liquid chamber. However, it is easy to increase the compliance of the first common liquid chamber. 
     (11) In the liquid ejecting head of the aspect, the first dimension may be equal to or larger than 3 times the second dimension. According to the liquid ejecting head of the aspect, it is easier to increase the volume of the first common liquid chamber. However, it is easy to increase the compliance of the first common liquid chamber. 
     (12) In the liquid ejecting head of the aspect, the second dimension may be 1 mm or less. According to the liquid ejecting head of the aspect, it is easy to reduce the size of the second common liquid chamber. Therefore, the liquid ejecting head can be more easily downsized. 
     (13) In the liquid ejecting head of the aspect, when, in a direction perpendicular to a nozzle surface at which the nozzle is formed, a direction from the pressure generating element to the nozzle surface may be one direction, a direction from the nozzle surface to the pressure generating element may be another direction, the first common liquid chamber may have an internal space extending both in the one direction from the pressure generating element and in the other direction from the pressure generating element, and the second common liquid chamber may have an internal space extending in the one direction from the pressure generating element. According to the liquid ejecting head of the aspect, it is easier to increase the volume of the first common liquid chamber. However, it is easy to increase the compliance of the first common liquid chamber. 
     (14) The liquid ejecting head of the aspect further includes: a first flow channel substrate in which the first common liquid chamber and the second common liquid chamber are formed; and a second flow channel substrate in which the first common liquid chamber is formed and the second common liquid chamber is not formed, in which the first flow channel substrate and the second flow channel substrate are stacked in a direction perpendicular to a nozzle surface at which the nozzle is formed. According to the liquid ejecting head of the aspect, it is easy to form the liquid ejecting head of the aspect. 
     (15) In the liquid ejecting head of the aspect, materials of the first flow channel substrate and the second flow channel substrate may be different from each other. According to the aspect, the liquid ejecting head can be provided in which the materials of the first flow channel substrate and the second flow channel substrate are different from each other. Therefore, the degree of freedom of design in the liquid ejecting head is improved. 
     The present disclosure can be realized in various forms other than the liquid ejecting head. For example, the present disclosure can be realized in the form of a liquid ejecting apparatus including the liquid ejecting head according to the above aspect and a method of manufacturing the liquid ejecting head and the liquid ejecting apparatus.