Patent Publication Number: US-11660866-B2

Title: Liquid ejecting head and liquid ejecting apparatus

Description:
The present application is a Continuation of U.S. patent application Ser. No. 17/167,386, filed Feb. 4, 2021, which is now U.S. Pat. No. 11,400,711, which is based on, and claims priority from, JP Application Serial Number 2020-019425, filed Feb. 7, 2020, the disclosures of which are hereby incorporated by reference herein in their entirety. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to liquid ejecting heads and liquid ejecting apparatuses. 
     2. Related Art 
     Liquid ejecting heads that eject liquid, such as ink, from multiple nozzles have been proposed. For example, JP-A-2013-184372 discloses a liquid ejecting head that ejects liquid from nozzles by changing the pressure of the liquid in pressure chambers with piezoelectric elements. This liquid ejecting head includes multiple nozzle channels each having a nozzle. The multiple nozzle channels are arrayed in a predetermined direction. 
     In known liquid ejecting heads, vibration in one of two adjacent nozzle channels propagates to the other nozzle channel to decrease the ejection characteristics of the ink through the nozzle of the other nozzle channel, possibly causing so-called structural crosstalk. 
     If the resistance of the nozzle channels increases, it takes much time to supply the liquid, possibly causing ejection failure and increasing the recording time. 
     SUMMARY 
     Accordingly, it is an object of the present disclosure to reduce the occurrence of structural crosstalk while preventing an increase in the resistance of the nozzle channels. 
     A liquid ejecting head according to an aspect of the present disclosure includes a first pressure chamber that extends in a first direction and that applies pressure to liquid, a second pressure chamber that extends in the first direction and that applies pressure to the liquid, a first nozzle channel that extends in the first direction and that includes a first nozzle that ejects the liquid. a first communication channel that extends in a second direction intersecting the first direction and that communicates between the first pressure chamber and the first nozzle channel, and a second communication channel that extends in the second direction and that communicates between the second pressure chamber and the first nozzle channel, wherein the first nozzle channel includes a first portion including an end of the first nozzle channel and a second portion including another end of the first nozzle channel, and a width of the second portion in the second direction is larger than a width of the first portion in the second direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram illustrating a partial configuration example of a liquid ejecting apparatus according to a first embodiment. 
         FIG.  2    is a schematic diagram illustrating a channel structure in a liquid ejecting head. 
         FIG.  3    is a cross-sectional view taken along line III-III in  FIG.  2   . 
         FIG.  4    is a cross-sectional view taken along line IV-IV in  FIG.  2   . 
         FIG.  5    is a side view of an individual channel illustrating a configuration example. 
         FIG.  6    is a side view of an individual channel illustrating a configuration example. 
         FIG.  7    is a cross-sectional view taken along line VII-VII in  FIGS.  5  and  6   . 
         FIG.  8    is a cross-sectional view taken along line VIII-VIII in  FIGS.  5  and  6   . 
         FIG.  9    is a cross-sectional view taken along line IX-IX in  FIGS.  5  and  6    according to a comparative example of the present disclosure. 
         FIG.  10    is a cross-sectional view taken along line X-X in  FIGS.  5  and  6    according to the comparative example. 
         FIG.  11    is a cross-sectional view taken along line XI-XI in  FIGS.  5  and  6    according to another comparative example of the present disclosure. 
         FIG.  12    is a cross-sectional view taken along line XII-XII in  FIGS.  5  and  6    according to the comparative example. 
         FIG.  13    is a schematic diagram illustrating a channel structure in a liquid ejecting head according to a second embodiment. 
         FIG.  14    is a schematic diagram illustrating a channel structure in a liquid ejecting head according to a third embodiment. 
         FIG.  15    is a cross-sectional view taken along line XV-XV in  FIG.  14    according to the third embodiment. 
         FIG.  16    is a cross-sectional view taken along line XVI-XVI in  FIG.  14    according to the third embodiment. 
         FIG.  17    is a cross-sectional view taken along line XVII-XVII in  FIG.  14    according to a fourth embodiment. 
         FIG.  18    is a cross-sectional view taken along line XVIII-XVIII in  FIG.  14    according to the fourth embodiment. 
         FIG.  19    is a cross-sectional view taken along line XIX-XIX in  FIG.  14    according to a fifth embodiment. 
         FIG.  20    is a cross-sectional view taken along line XX-XX in  FIG.  14    according to the fifth embodiment. 
         FIG.  21    is a schematic diagram illustrating a channel structure in a liquid ejecting head according to a sixth embodiment. 
         FIG.  22    is a cross section taken along line XXII-XXII in  FIG.  21   . 
         FIG.  23    is a cross-sectional view taken along line XXIII-XXIII in  FIG.  21   . 
         FIG.  24    is a schematic diagram illustrating a channel structure in a liquid ejecting head according to a seventh embodiment. 
         FIG.  25    is a cross-sectional view taken along line XXV-XXV in  FIG.  24   . 
         FIG.  26    is a cross-sectional view taken along line XXVI-XXVI in  FIG.  24   . 
         FIG.  27    is an enlarged cross-sectional view of any one nozzle. 
         FIG.  28    is a schematic diagram illustrating a channel structure in a liquid ejecting head according to a modification. 
         FIG.  29    is a cross-sectional view taken along line XXIX-XXIX in  FIG.  28   . 
         FIG.  30    is a cross-sectional view taken along line XXX-XXX in  FIG.  28   . 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     First Embodiment 
     In the following description, assume X-axis, Y-axis, and Z-axis that intersect one another. The X-axis, the Y-axis, and the Z-axis are common in all the drawings illustrated in the description. As shown in  FIG.  1   , a direction along the X-axis as viewed from any point is expressed as X1-direction, and a direction opposite to the X1-direction is expressed as X2-direction. The X1-direction corresponds to “first direction”. Likewise, directions opposite to each other from any point along the Y-axis are expressed as Y1-direction and Y2-direction. The Y2-direction corresponds to “third direction”. Directions opposite to each other from any point along the Z-axis are expressed as Z1-direction and Z2-direction. The Z1-direction corresponds to “second direction”. An X-Y plane including the X-axis and the Y-axis corresponds to a horizontal plane. The Z-axis is an axis along the vertical direction, and the Z2-direction corresponds to a downward direction in the vertical direction. 
       FIG.  1    is a schematic diagram illustrating a partial configuration example of a liquid ejecting apparatus  100  according to this embodiment. The liquid ejecting apparatus  100  is an ink jet printer that ejects droplets of liquid, such as ink, onto a medium  11 . An example of the medium  11  is printing paper. The medium  11  may be a print target of any material, such as resin film or cloth. 
     The liquid ejecting apparatus  100  includes a liquid container  12 . The liquid container  12  stores ink. The liquid container  12  may be a cartridge that can be detached from the liquid ejecting apparatus  100 , a bag-like ink pack made of flexible film, or an ink tank that can be refilled with ink. Any kind of ink can be stored in the liquid container  12 . 
     As shown in  FIG.  1   , the liquid ejecting apparatus  100  includes a control unit  21 , a transporting mechanism  22 , a moving mechanism  23 , and a liquid ejecting head  24 . The control unit  21  includes a processing circuit, such as a central processing unit (CPU) or a field programmable gate array (FPGA), and a storage circuit, such as a semiconductor memory, and controls the elements of the liquid ejecting apparatus  100 , such as the ejecting operation of the liquid ejecting head  24 . The control unit  21  is an example of “control section”. 
     The transporting mechanism  22  transports the medium  11  along the Y-axis based on the control of the control unit  21 . The moving mechanism  23  moves the liquid ejecting head  24  back and forth along the X-axis based on the control of the control unit  21 . The moving mechanism  23  includes a substantially box-shaped transporter  231  housing the liquid ejecting head  24  and an endless transport belt  232  to which the transporter  231  is fixed. This embodiment may employ a configuration in which multiple liquid ejecting heads  24  are mounted in the transporter  231  and a configuration in which the liquid container  12  is mounted in the transporter  231  together with the liquid ejecting head  24 . 
     The liquid ejecting head  24  ejects the ink supplied from the liquid container  12  onto the medium  11  through each of the multiple nozzles based on the control of the control unit  21 . The liquid ejecting head  24  ejects the ink onto the medium  11  in parallel with the transportation of the medium  11  by the transporting mechanism  22  and repeated reciprocal motion of the transporter  231  to form an image on the surface of the medium  11 . 
       FIG.  2    is a schematic diagram illustrating a channel structure in the liquid ejecting head  24  as viewed in the Z-axis. Multiple nozzles Na and multiple nozzles Nb are provided on the surface of the liquid ejecting head  24  facing the medium  11 , as shown in  FIG.  2   . The nozzles Na and the nozzles Nb are arrayed along the Y-axis. Each of the nozzles Na and the nozzles Nb ejects ink in the Z-axis direction. Accordingly, the Z-axis direction corresponds to a direction in which ink is ejected through each of the nozzles Na and the nozzles Nb. The nozzle Na is an example of “first nozzle”, and the nozzle Nb is an example of “second nozzle”. 
     As shown in  FIG.  2   , the nozzles Na constitute a first nozzle array La, and the nozzles Nb constitute a second nozzle array Lb. The first nozzle array La is an aggregation of the multiple nozzles Na arrayed linearly along the Y-axis. Likewise, the second nozzle array Lb is an aggregation of the multiple nozzles Nb arrayed linearly along the Y-axis. The first nozzle array La and the second nozzle array Lb are disposed in parallel in the X-axis, with a space therebetween, as shown in  FIG.  2   . The position of each nozzle Na in the Y-axis direction and the position of each nozzle Nb in the Y-axis direction differ. As shown in  FIG.  2   , the nozzles N including the nozzles Na and the nozzles Nb are arrayed at a pitch (cycle) of θ. The pitch θ is the distance between the center of the nozzle Na and the center of the nozzle Nb in the Y-axis direction. In the following description, the signs of elements related to the nozzles Na of the first nozzle array La are given subscript a, and the signs of elements related to the nozzles Nb of the second nozzle array Lb are given subscript b. If there is no particular need to distinguish the nozzles Na of the first nozzle array La and the nozzles Nb of the second nozzle array Lb from each other, the nozzles Na and the nozzles Nb are each simply expressed as “nozzle N”. 
     The liquid ejecting head  24  includes an individual channel array  25 , as shown in  FIG.  2   . The individual channel array  25  is an aggregation of multiple individual channels Pa and multiple individual channels Pb. Each of the individual channels Pa extends in the X1-direction and corresponds to one of the different nozzles Na. The individual channels Pa communicate individually with the nozzles Na. Likewise, each of the individual channels Pb extends in the X1-direction and corresponds to one of the different nozzles Nb. The individual channels Pb communicate individually with the nozzles Nb. The details of the configuration of the individual channels Pa and the individual channels Pb will be described later. In the following description, if there is no particular need to distinguish the individual channels Pa and the individual channels Pb from each other, the individual channels Pa and the individual channels Pb are each simply referred to as “individual channel P”. 
     The individual channels Pa and the individual channels Pb facing in the Y-axis direction has an inverted relationship about the Z-axis. Specifically, rotating the individual channels Pa 180° about the Z-axis brings the individual channels Pa to the same disposition as that of the individual channels Pb, and rotating the individual channels Pb 180° about the Z-axis brings the individual channels Pb to the same disposition as that of the individual channels Pa. 
     As shown in  FIG.  2   , the individual channels Pa each include a pressure chamber Ca 1  and a pressure chamber Ca 2 . The pressure chamber Ca 1  and the pressure chamber Ca 2  in the individual channel Pa extend in the X1-direction. The pressure chamber Ca 1  and the pressure chamber Ca 2  store the ink to be ejected from the nozzle Na communicating with the individual channel Pa. When the pressure in the pressure chamber Ca 1  and the pressure chamber Ca 2  changes, the ink is ejected from the nozzle Na. The pressure chamber Ca 1  is an example of “first pressure chamber”, and the pressure chamber Ca 2  is an example of “second pressure chamber”. Likewise, the individual channels Pb each include a pressure chamber Cb 1  and a pressure chamber Cb 2 . The pressure chamber Cb 1  and the pressure chamber Cb 2  in the individual channel Pb extend in the X1-direction. The pressure chamber Cb 1  and the pressure chamber Cb 2  store the ink to be ejected from the nozzle Nb communicating with the individual channel Pb. When the pressure in the pressure chamber Cb 1  and the pressure chamber Cb 2  changes, the ink is ejected from the nozzle Nb. The pressure chamber Cb 1  is an example of “third pressure chamber”, and the pressure chamber Cb 2  is an example of “fourth pressure chamber”. In the following description, if there is no particular need to distinguish the pressure chambers Ca 1  and Ca 2  corresponding to the first nozzle array La and the pressure chambers Cb 1  and Cb 2  corresponding to the second nozzle array Lb, the pressure chambers Ca 1 , Ca 2 , Cb 1 , and Cb 2  are each simply referred to as “pressure chamber C”. 
     The liquid ejecting head  24  includes a first common liquid chamber R 1  and a second common liquid chamber R 2 , as shown in  FIG.  2   . The first common liquid chamber R 1  and the second common liquid chamber R 2  extend in the Y-axis direction across the entire area in which the multiple nozzles N are distributed. The individual channel array  25  and the multiple nozzles N are located between the first common liquid chamber R 1  and the second common liquid chamber R 2  in plan view in the Z-axis direction. In the following description, the plan view in the Z-axis direction is simply referred to as “plan view”. 
     The multiple individual channels P communicate, in common, with the first common liquid chamber R 1 . Specifically, an end E 1  of each individual channel P in the X2-direction is coupled to the first common liquid chamber R 1 . Likewise, the multiple individual channels P communicate, in common, with the second common liquid chamber R 2 . Specifically, an end E 2  of each individual channel P in the X1-direction is coupled to the second common liquid chamber R 2 . In the liquid ejecting head  24 , the individual channels P communicate between the first common liquid chamber R 1  and the second common liquid chamber R 2 . This allows the ink supplied from the first common liquid chamber R 1  to the individual channels P to be ejected through the nozzles N. The ink that was not ejected is discharged into the second common liquid chamber R 2 . 
     The liquid ejecting head  24  includes a circulating mechanism  26 , as shown in  FIG.  2   . The circulating mechanism  26  is a mechanism for circulating the ink discharged from the individual channels P into the second common liquid chamber R 2  back to the first common liquid chamber R 1 . The circulating mechanism  26  includes a first supply pump  261 , a second supply pump  262 , a reserve container  263 , a circulation channel  264 , and a supply channel  265 . 
     The first supply pump  261  is a pump that supplies the ink stored in the liquid container  12  to the reserve container  263 . The reserve container  263  is a subtank that temporarily stores the ink supplied from the liquid container  12 . 
     The circulation channel  264  is a channel that communicates between the second common liquid chamber R 2  and the reserve container  263 . The ink is discharged through a discharge channel Ra 2  and a discharge channel Rb 2  (described later) via the second common liquid chamber R 2 . The circulation channel  264  and the second common liquid chamber R 2  are examples of “common discharge channel”. 
     The reserve container  263  is supplied with the ink stored in the liquid container  12  by the first supply pump  261  and is also supplied with the ink discharged from the individual channels P into the second common liquid chamber R 2 , through the circulation channel  264 . 
     The second supply pump  262  is a pump that pumps out the ink stored in the reserve container  263 . The ink pumped out by the second supply pump  262  is supplied to the first common liquid chamber R 1  through the supply channel  265 . The supply channel  265  supplies the liquid to a supply channel Ra 1  and a supply channel Rb 1  (described later), in common. The supply channel  265  and the first common liquid chamber R 1  are examples of “common supply channel”. 
     The individual channels P of the individual channel array  25  include the individual channels Pa and the individual channels Pb. Each of the individual channels Pa is an individual channel P communicating with corresponding one of the nozzles Na in the first nozzle array La. Each of the individual channels Pb is an individual channel P communicating with corresponding one of the nozzles Nb in the second nozzle array Lb. The individual channels Pa and the individual channels Pb are alternately arrayed along the Y-axis. Thus, the individual channels Pa and the individual channels Pb face each other in the Y-axis direction. 
     The individual channels Pa each include a nozzle channel Nfa, as shown in  FIG.  2   . The nozzle channel Nfa extends in the X1-direction and is positioned between the pressure chamber Ca 1  and the pressure chamber Ca 2  as viewed in the Z2 direction, as shown in  FIG.  2   . The nozzle channel Nfa communicates between the pressure chamber Ca 1  and the pressure chamber Ca 2  and includes the nozzle Na that ejects the ink supplied from the pressure chamber Ca 1 . The nozzle channel Nfa is an example of “first nozzle channel”. 
     The individual channels Pb each include a nozzle channel Nfb, as shown in  FIG.  2   . The nozzle channel Nfb extends in the X1-direction and is positioned between the pressure chamber Cb 1  and the pressure chamber Cb 2  as viewed in the Y-axis direction, as shown in  FIG.  2   . The nozzle channel Nfb communicates between the pressure chamber Cb 1  and the pressure chamber Cb 2  and includes the nozzle Nb that ejects the ink supplied from the pressure chamber Cb 1 . The nozzle channel Nfb is an example of “second nozzle channel”. 
     The nozzle channels Nfa are arrayed in the Y-axis direction. The nozzle channels Nfb are arrayed in the Y-axis direction. The nozzle channel Nfa and the nozzle channel Nfb are disposed in parallel in the Y-axis direction, with a predetermined space therebetween. The nozzle channel Nfa and the nozzle channel Nfb adjacent in the Y-axis direction have an inverted relationship about the Z-axis. In the present application, “element A and element B are adjacent to each other” refers to “at least part of element A and at least part of element B face each other as viewed in a specific direction”. Not the whole of element A and the whole of element B need to face each other. If at least part of element A and at least part of element B face, then it is determined that “element A and element B are adjacent to each other”. 
     In the liquid ejecting head  24  of this embodiment, as shown in  FIG.  2   , the pressure chambers Ca 1  for the different nozzles Na of the first nozzle array La and the pressure chambers Cb 1  for the different nozzles Nb of the second nozzle array Lb are arrayed in parallel in the Y-axis direction. Likewise, the pressure chambers Ca 2  for the different nozzles Na of the first nozzle array La and the pressure chambers Cb 2  for the different nozzles Nb of the second nozzle array Lb are arrayed in parallel in the Y-axis direction. The array of the pressure chambers Ca 1  and the pressure chambers Cb 1  and the array of the pressure chambers Ca 2  and the pressure chambers Cb 2  are disposed in parallel in the X-axis direction, with a predetermined space therebetween. Although the positions of the pressure chambers Ca 1  in the Y-axis direction and the positions of the pressure chambers Ca 2  in the Y-axis direction are the same, the positions may differ. Although the positions of the pressure chambers Cb 1  in the Y-axis direction and the positions of the pressure chambers Cb 2  in the Y-axis direction are the same, the positions may differ. 
     Next, the details of the configuration of the liquid ejecting head  24  will be described.  FIG.  3    is a cross-sectional view taken along line III-III in  FIG.  2   .  FIG.  4    is a cross-sectional view taken along line IV-IV in  FIG.  2   .  FIG.  3    illustrates a cross section passing through the individual channel Pa.  FIG.  4    illustrates a cross section passing through the individual channel Pb. 
     As shown in  FIGS.  3  and  4   , the liquid ejecting head  24  includes a channel structure  30 , multiple piezoelectric elements  41 , a casing  42 , a protective substrate  43 , and a wiring substrate  44 . The channel structure  30  is a structure in which a channel including the first common liquid chamber R 1 , the second common liquid chamber R 2 , the individual channels P, and the nozzles N are formed. 
     The channel structure  30  is a structure in which a nozzle plate  31 , a communication plate  33 , a pressure chamber substrate  34 , and a vibration plate  35  are layered in order in the Z1-direction. These elements constituting the channel structure  30  are produced by processing a silicon monocrystal substrate by, for example, a general processing method for producing a semiconductor. 
     The nozzle plate  31  has the multiple nozzles N formed therein. Each of the nozzles N is a cylindrical through-hole through which the ink is to be passed. As shown in  FIGS.  3  and  4   , the nozzle plate  31  is a plate-like member having a surface Fa 1  facing in the Z2-direction and a surface Fa 2  facing in the Z1-direction. The communication plate  33  is a plate-like member having a surface Fc 1  facing in the Z2-direction and a surface Fc 2  facing in the Z1-direction. 
     The elements constituting the channel structure  30  are each formed in a rectangular shape that is long in the Y-axis direction and are bonded to each other with, for example, an adhesive. For example, the surface Fa 2  of the nozzle plate  31  is bonded to the surface Fc 1  of the communication plate  33 , and the surface Fc 2  of the communication plate  33  is bonded to a surface Fd 1  of the pressure chamber substrate  34 . A surface Fd 2  of the pressure chamber substrate  34  is bonded to a surface Fc 1  of the vibration plate  35 . 
     The communication plate  33  has a space O 12  and a space O 22 . Each of the space O 12  and the space O 22  is an opening that is long in the Y-axis direction. On the surface Fc 1  of the communication plate  33 , a vibration absorber  361  that closes the space O 12  and a vibration absorber  362  that closes the space O 22  are disposed. The vibration absorber  361  and the vibration absorber  362  are layered members made of an elastic material. 
     The casing  42  is a case for storing ink. The casing  42  is joined to the surface Fc 2  of the communication plate  33 . The casing  42  has a space O 13  communicating with the space O 12  and a space O 23  communicating with the space O 22 . Each of the space O 13  and the space O 23  is a space that is long in the Y-axis direction. The space O 12  and the space O 13  communicate with each other to form the first common liquid chamber R 1 . Likewise, the space O 22  and the space O 23  communicate with each other to form the second common liquid chamber R 2 . The vibration absorber  361  constitutes a wall surface of the first common liquid chamber R 1  and absorbs a pressure change of the ink in the first common liquid chamber R 1 . The vibration absorber  362  constitutes a wall surface of the second common liquid chamber R 2  and absorbs a pressure change of the ink in the second common liquid chamber R 2 . 
     The casing  42  has a supply port  421  and a discharge port  422 . The supply port  421  is a conduit communicating with the first common liquid chamber R 1  and is coupled to the supply channel  265  of the circulating mechanism  26 . The ink pumped out by the second supply pump  262  into the supply channel  265  is supplied to the first common liquid chamber R 1  through the supply port  421 . The discharge port  422  is a conduit communicating with the second common liquid chamber R 2  and is coupled to the circulation channel  264  of the circulating mechanism  26 . The ink in the second common liquid chamber R 2  is supplied to the circulation channel  264  through the discharge port  422 . 
     The pressure chamber substrate  34  is provided with the pressure chambers Ca 1  and Ca 2  and the pressure chambers Cb 1  and Cb 2 . The pressure chambers C are spaces between the surface Fc 2  of the communication plate  33  and the vibration plate  35 . The pressure chambers C are long along the X-axis and extends in the X1-direction in plan view. 
     The vibration plate  35  is an elastically vibratile plate-like member. The vibration plate  35  is a lamination of, for example, a first layer made of silicon oxide (SiO2) and a second layer made of zirconium oxide (ZrO2). The vibration plate  35  and the pressure chamber substrate  34  may be integrally formed by selectively removing, in the thickness direction, a part of the plate-like member with a predetermined thickness corresponding to the pressure chamber C. The vibration plate may be of a single layer. 
     On the surface Fe 2  of the vibration plate  35 , the piezoelectric elements  41  for the different pressure chambers C are disposed. The piezoelectric elements  41  for the individual pressure chambers C overlap with the pressure chambers C in plan view. Specifically, each piezoelectric element  41  is a lamination of a first electrode and a second electrode facing each other and a piezoelectric layer formed between the electrodes. The piezoelectric element  41  is an energy generating element that ejects the ink in the pressure chamber C through the nozzle N by generating energy to change the pressure of the ink in the pressure chamber C. The piezoelectric element  41  vibrates the vibration plate  35  by deforming the piezoelectric element  41  itself by receiving a driving signal. When the vibration plate  35  vibrates, the pressure chamber C expands and contracts. The expansion and contraction of the pressure chamber C cause pressure to be exerted to the ink from the pressure chamber C. This causes the ink to be ejected through the nozzle N. 
     The protective substrate  43  is a plate-like member disposed on the surface Fe 2  of the vibration plate  35 . The protective substrate  43  protects the piezoelectric elements  41  and also reinforces the mechanical strength of the vibration plate  35 . The piezoelectric elements  41  are housed between the protective substrate  43  and the vibration plate  35 . The wiring substrate  44  is disposed on the surface Fe 2  of the vibration plate. The wiring substrate  44  is a surface-mounted component for electrically coupling the control unit  21  and the liquid ejecting head  24  together. Preferable examples of the wiring substrate  44  include a flexible printed circuit (FPC) and a flexible flat cable (FFC). On the wiring substrate  44 , a driving circuit  45  for supplying a driving signal to each piezoelectric element  41  is mounted. 
     Next, the details of the configuration of the individual channels P will be described.  FIG.  5    is a side view of the individual channel Pa illustrating a configuration example in which the individual channel Pa and the individual channel Pb face each other. As shown in  FIG.  5    and  FIG.  6    (described later), the shape of the individual channel Pa and the shape of the individual channel Pb have a rotationally symmetrical relationship about the axis of symmetry parallel to the Z-axis in plan view. 
     As shown in  FIG.  5   , the individual channel Pa includes the supply channel Ra 1 , the pressure chamber Ca 1 , a first communication channel Na 1 , the nozzle channel Nfa, a second communication channel Na 2 , the pressure chamber Ca 2 , and the discharge channel Ra 2 . The individual channel Pa is a channel in which these elements are integrated and coupled in the above order. As shown in  FIG.  5   , a first portion Pa 1  of the nozzle channel Nfa and a third portion Pb 1  of the nozzle channel Nfb overlap at least partially in the X1-direction. The whole of the third portion Pb 1  overlap with the first portion Pa 1  in the X1-direction, as shown in  FIG.  5   . 
     The supply channel Ra 1  is a space formed in the communication plate  33 . Specifically, as shown in  FIG.  3   , the supply channel Ra 1  extends from the space O 12  constituting the first common liquid chamber R 1  to the surface Fc 2  of the communication plate  33  along the Z-axis. An end of the supply channel Ra 1  coupled to the space O 12  is the end E 1  of the individual channel Pa. The supply channel Ra 1  is a channel communicating with the pressure chamber Ca 1  to introduce the ink supplied from the first common liquid chamber R 1  into the pressure chamber Ca 1 . The supply channel Ra 1  is an example of “first individual supply channel”. 
     As shown in  FIG.  3   , the first communication channel Na 1  is a space passing through the communication plate  33 . The first communication channel Na 1  is a long channel extending along the Z-axis. The first communication channel Na 1  extends in the Z1-direction to communicate between the pressure chamber Ca 1  and the nozzle channel Nfa. The first communication channel Na 1  is a channel that introduces the ink expelled from the pressure chamber Ca 1  into the nozzle channel Nfa. 
     The nozzle channel Nfa is a channel provided in the communication plate  33  and extending in the X-axis direction. As shown in  FIG.  3   , the nozzle channel Nfa is segmented into the first portion Pa 1  and a second portion Pa 2 . In this embodiment, the side at which the pressure chamber Ca 1  and the pressure chamber Ca 2  are positioned in the Z1-direction as viewed from the nozzle channel Nfa is referred to as “first side”, and the side at which the nozzle Na is positioned in the Z2-direction is referred to as “second side”. A channel wall surface Sa 1  of the first portion Pa 1  on the first side and a channel wall surface Sa 2  of the second portion Pa 2  on the first side are at different positions in the Z1-direction. A channel wall surface Sa 3  of the first portion Pa 1  on the second side and a channel wall surface Sa 4  of the second portion Pa 2  on the second side are at the same position in the Z2-direction. In other words, the first portion Pa 1  has the channel wall surface Sa 1  and the channel wall surface Sa 3 . The channel wall surface Sa 3  is positioned between the ink ejecting plane of the nozzle Na and the channel wall surface Sa 1  in the Z1-direction. Likewise, the second portion Pa 2  has the channel wall surface Sa 2  and the channel wall surface Sa 4 . The channel wall surface Sa 4  is positioned between the ink ejecting plane of the nozzle Na and the channel wall surface Sa 2  in the Z1-direction. 
     The first portion Pa 1  is a channel positioned between the first communication channel Na 1  and the second portion Pa 2  in the X-axis direction and extending in the X-axis direction. The first portion Pa 1  communicates between the first communication channel Na 1  and the second portion Pa 2  and includes the nozzle Na. The first portion Pa 1  has an end E 3  positioned in the X2-direction and an end E 4  positioned in the X1-direction. An end of the nozzle channel Nfa coupled to the first communication channel Na 1  is the end E 3  of the first portion Pa 1 . In other words, the first portion Pa 1  includes an end of the nozzle channel Nfa positioned in the X2-direction. The first portion Pa 1  is a channel that guides the ink supplied through the first communication channel Na 1  but not ejected from the nozzle Na to the second portion Pa 2 . The width W 1  of the first portion Pa 1  in the X1-direction is larger than the width W 3  of the second portion Pa 2  in the X1-direction, as shown in  FIG.  3   . 
     The second portion Pa 2  is a channel positioned between the first portion Pa 1  and the second communication channel Na 2  in the X-axis direction and extending by a predetermined amount in the X-axis direction and the Z-axis direction. The second portion Pa 2  communicates between the first portion Pa 1  and the second communication channel Na 2  and has an end E 5  positioned in the X2-direction and an end E 6  positioned in the X1-direction. An end of the nozzle channel Nfa coupled to the second communication channel Na 2  is the end E 6  of the second portion Pa 2 , and an end E 4  of the first portion Pa 1  coupled to the second portion Pa 2  is the end E 5  of the second portion Pa 2 . In other words, the second portion Pa 2  includes an end of the nozzle channel Nfa positioned in the X1-direction. The second portion Pa 2  is a channel that introduces the ink supplied from the first portion Pa 1  into the second communication channel Na 2 . 
     As shown in  FIG.  3   , the width W 3  of the second portion Pa 2  in the X1-direction is smaller than the width W 1  of the first portion Pa 1  in the X1-direction. The width W 10  of the second portion Pa 2  in the Z1-direction is larger than the width W 9  of the first portion Pa 1  in the Z1-direction, as shown in  FIG.  3   . This allows reducing structural crosstalk. The details will be described later. The “structural crosstalk” is a phenomenon in which a vibration caused by a change in the inner pressure of one individual channel propagates to the other individual channel to decrease the ejection characteristics of the nozzle communicating with the individual channel. The definition of the structural crosstalk applies also to the following description. 
     The second communication channel Na 2  is a space passing through the communication plate  33 . The second communication channel Na 2  is a long channel extending along the Z-axis. The second communication channel Na 2  extends in the Z1-direction to communicate between the pressure chamber Ca 2  and the nozzle channel Nfa. The second communication channel Na 2  is a channel that introduces the ink supplied from the second portion Pa 2  into the pressure chamber Ca 2 . 
     The discharge channel Ra 2  is a space formed in the communication plate  33 . Specifically, the discharge channel Ra 2  extends from the space O 22  constituting the second common liquid chamber R 2  to the surface Fc 2  of the communication plate  33  along the Z-axis. An end of the discharge channel Ra 2  coupled to the space O 22  is the end E 2  of the individual channels Pa. The discharge channel Ra 2  is a channel communicating with the pressure chamber Ca 2  to introduce the ink expelled from the pressure chamber Ca 2  into the second common liquid chamber R 2 . The discharge channel Ra 2  is an example of “first individual discharge channel”. 
     With the above configuration, the liquid ejecting head  24  ejects ink while circulating the ink during the operation of the liquid ejecting apparatus  100 . Specifically, the ink from the liquid container  12  is supplied to the first common liquid chamber R 1  through the supply channel  265 . Then, a driving unit including the driving circuit  45  outputs a driving signal for driving the piezoelectric element  41  to the piezoelectric element  41  for the pressure chamber Ca 1  and the piezoelectric element  41  for the pressure chamber Ca 2  to drive the piezoelectric element  41  for the pressure chamber Ca 1  and the piezoelectric element  41  for the pressure chamber Ca 2  at the same time. This causes the ink supplied to the first common liquid chamber R 1  to be ejected from the nozzle Na. Of the ink supplied to the first portion Pa 1 , the ink not ejected from the nozzle Na is supplied to the second common liquid chamber R 2  through the discharge channel Ra 2 . As will be understood from the above description, the first portion Pa 1  is a channel upstream of the nozzle channel Nfa, and the second portion Pa 2  is a channel downstream of the nozzle channel Nfa. The piezoelectric element  41  for the pressure chamber Ca 1  is an example of “first energy generating element”, and the piezoelectric element  41  for the pressure chamber Ca 2  is an example of “second energy generating element”. 
       FIG.  6    is a side view of the individual channel Pb illustrating a configuration example in which the individual channel Pa and the individual channel Pb face each other. The individual channel Pb has a configuration in which the individual channel Pa is inverted 180°. As shown in  FIG.  4   , the width W 9  of the fourth portion Pb 2  in the Z1-direction is smaller than the width W 10  of the third portion Pb 1  in the Z1-direction. The width W 7  of the fourth portion Pb 2  in the X1-direction is larger than the width W 5  of the third portion Pb 1  in the X1-direction. The width W 9  of the fourth portion Pb 2  in the Z1-direction is equal to the width W 9  of the first portion Pa 1  in the Z1-direction. The width W 10  of the third portion Pb 1  in the Z1-direction is equal to the width W 10  of the second portion Pa 2  in the Z1-direction. The width W 5  of the third portion Pb 1  in the X1-direction is equal to the width W 3  of the second portion Pa 2  in the X1-direction. The width W 7  of the fourth portion Pb 2  in the X1-direction is equal to the width W 1  of the first portion Pa 1  in the X1-direction. Specifically, as shown in  FIG.  6   , the individual channel Pb includes the supply channel Rb 1 , the pressure chamber Cb 1 , a third communication channel Nb 1 , a nozzle channel Nfb, a fourth communication channel Nb 2 , the pressure chamber Cb 2 , and the discharge channel Rb 2 . The nozzle channel Nfb has the third portion Pb 1  and the fourth portion Pb 2 . The individual channel Pb is a channel in which these elements are integrated and coupled in the above order. As shown in  FIG.  6   , the second portion Pa 2  and the fourth portion Pb 2  overlap at least partially in the X1-direction. The whole of the second portion Pa 2  overlap with the fourth portion Pb 2  in the X1-direction, as shown in  FIG.  6   . 
     The description of the structure of the individual channels Pa can be used as the description of the components of the individual channels Pb by replacing the subscript a of the signs of the elements of the individual channels Pa with subscript b. The supply channel Rb 1  is an example of “second individual supply channel”. The discharge channel Rb 2  is an example of “second individual discharge channel”. 
     With the above configuration, the liquid ejecting head  24  supplies the ink form the liquid container  12  to the first common liquid chamber R 1  through the supply channel  265 . Then, the driving unit including the driving circuit  45  outputs a driving signal for driving the piezoelectric element  41  to the piezoelectric element  41  for the pressure chamber Cb 1  and the piezoelectric element  41  for the pressure chamber Cb 2  to drive the piezoelectric element  41  for the pressure chamber Cb 1  and the piezoelectric element  41  for the pressure chamber Cb 2  at the same time. This causes the ink supplied to the first common liquid chamber R 1  to be ejected from the nozzle Nb. Of the ink supplied to the third portion Pb 1 , the ink not ejected from the nozzle Nb is supplied to the second common liquid chamber R 2  through the discharge channel Rb 2 . As will be understood from the above description, the third portion Pb 1  is a channel upstream of the nozzle channel Nfb, and the fourth portion Pb 2  is a channel downstream of the nozzle channel Nfb. 
     The liquid ejecting head  24  of this embodiment prevents the ink ejection characteristics from becoming worse by circulating the ink during ejection to prevent the ink in the vicinity of the nozzles Na and Nb from becoming thick and the component from being precipitated. This allows the ink ejection characteristics to be made approximately even to prevent variations in ejection characteristics, improving the ink ejection quality. Examples of the “ejection characteristics” include an ink ejection rate and an ink ejection speed. 
       FIG.  7    is a cross-sectional view taken along line VII-VII in  FIGS.  5  and  6   .  FIG.  8    is a cross-sectional view taken along line VIII-VIII in  FIGS.  5  and  6   . As shown in  FIGS.  5  to  7   , the first portion Pa 1  and the third portion Pb 1  are alternately arranged along the Y-axis direction in the cross-sectional view taken along line VII-VII. As shown in  FIGS.  5 ,  6  and  8   , the second portion Pa 2  and the fourth portion Pb 2  are alternately arranged in the Y-axis direction in the cross-sectional view taken along line VIII-VIII. 
     As shown in  FIGS.  7  and  8   , the first portion Pa 1  and the fourth portion Pb 2  have a width of W 2  in the Y-axis direction and a width of W 9  in the Z-axis direction. The second portion Pa 2  and the third portion Pb 1  have a width of W 4  in the Y-axis direction and a width of W 10  in the Z-axis direction. The width W 4  is equal to the width W 2 , and the width W 10  is larger than the width W 9 . 
     The cross-sectional area of the nozzle channel Nfa viewed from the X-axis direction is as small as W 2 ×W 9  in the first portion Pa 1  but is as large as W 4 ×W 10  in the second portion Pa 2 , so that the channel resistance of the entire nozzle channel Nfa is relatively small. Likewise, the channel cross-sectional area of the nozzle channel Nfb viewed from the X-axis direction is as small as W 2 ×W 9  in the fourth portion Pb 2  but is as large as W 4 ×W 10  in the third portion Pb 1 , so that the channel resistance of the entire nozzle channel Nfb is relatively small. 
     In the VII-VII cross-section of  FIG.  7   , the first portion Pa 1  with a width of W 9  in the Z-axis direction and the third portion Pb 1  with a width of W 10  in the Z-axis direction, which is larger than W 9 , are disposed so as to be adjacent to each other in the Y-axis direction. Accordingly, in a range Eb 1 , the third portion Pb 1  is present, but the first portion Pa 1  is not present, as shown in  FIG.  7   . In other words, the channel is present at adjacent positions in the Y-axis direction in a range Eb 2  but is not present at adjacent positions in the Y-axis direction in the range Eb 1  which is the difference between W 10  and W 9  in the Z-axis direction. For that reason, even if a vibration due to ink flow is generated in the third portion Pb 1  in the range Eb 1 , the vibration is less likely to be transmitted to the first portion Pa 1  because the first portion Pa 1  is not present at the overlapping position in the Z-axis direction, reducing the influence on the ejection from the nozzle Na. In other words, structural crosstalk is unlikely to occur. Also for the VIII-VIII cross section of  FIG.  8   , since the fourth portion Pb 2  is not present at the position overlapping with the second portion Pa 2  in range Ea 1  in the Z-axis direction, a vibration from the second portion Pa 2  in range Ea 1  is less likely to be transmitted to the fourth portion Pb 2 , reducing the possibility of structural crosstalk. 
     Thus, this embodiment allows for reducing structural crosstalk while preventing an increase in the channel resistance of the nozzle channel Nfa and the nozzle channel Nfb. 
     Comparative Example 1 
       FIG.  9    is a cross-sectional view taken along line IX-IX in  FIGS.  5  and  6    according to a comparative example of the present disclosure.  FIG.  10    is a cross-sectional view taken along line X-X in  FIGS.  5  and  6    according to the comparative example. In comparative example 1, the first portion Pa 1  and the fourth portion Pb 2  have a width of W 11  in the Z-axis direction. Other than that, the comparative example 1 is similar to the first embodiment. The width W 11  is equal to the width W 10 , as shown in  FIGS.  9  and  10   , and is larger than the width W 9 , shown in  FIGS.  7  and  8   . 
     In comparative example 1, the first portion Pa 1  and the third portion Pb 1  with a width of W 11  in the Z-axis direction are adjacent to each other in the Y-axis direction, as shown in the IX-IX cross section of  FIG.  9   . In other words, the range Eb 1  in which no channel is present in adjacent positions in the Y-axis direction is not present, unlike the first embodiment. In the first embodiment, the width of the range Eb 2  in the Z-axis direction in which the channel is present at adjacent positions in the Y-axis direction is the width W 9 , while, in the comparative example 1, the width is as large as W 10 . Accordingly, when vibration occurs in the third portion Pb 1 , it exerts large influence on the ejection from the nozzle Na in the first portion Pa 1 . In other words, structural crosstalk is likely to occur. The principle in which the structural crosstalk is likely to occur applies also to the X-X cross section of  FIG.  10   . 
     Thus, the configuration of the liquid ejecting head  24  according to comparative example 1 can cause significant structural crosstalk. 
     Comparative Example 2 
       FIG.  11    is a cross-sectional view taken along line XI-XI in  FIGS.  5  and  6    according to another comparative example of the present disclosure.  FIG.  12    is a cross-sectional view taken along line XII-XII in  FIGS.  5  and  6    according to the comparative example. In comparative example 2, the second portion Pa 2  and the third portion Pb 1  have a width of W 12  in the Z-axis direction. Other than that, the comparative example 2 has a similar configuration to the configuration of the first embodiment. The width W 12  is equal to the width W 9 , as shown in  FIG.  11   , and is smaller than the width W 10 , shown in  FIGS.  7  and  8   . 
     In comparative example 2, as shown in  FIGS.  11  and  12   , the channel cross-sectional area of the nozzle channel Nfa viewed from the X-axis direction is W 2 ×W 9  in the first portion Pa 1  and W 4 ×W 12  in the second portion Pa 2 . Thus, the channel cross-sectional areas in the first portion Pa 1  and the second portion Pa 2  are small, increasing the channel resistance of the entire nozzle channel Nfa. The channel resistance increases because of the above principle applies also to the nozzle channel Nfb. 
     Thus, the channel resistance increases in comparative example 2. 
     Second Embodiment 
       FIG.  13    is a schematic diagram illustrating a channel structure in a liquid ejecting head  24  according to a second embodiment as viewed in the Z-axis direction. Components similar to those of the first embodiment are given the same reference signs, and detailed descriptions thereof will be omitted or simplified. 
     The second embodiment has the same configuration as that of the first embodiment except that the widths of the first portion Pa 1  and the fourth portion Pb 2  in the Y-axis direction are W 13 , and the widths of the second portion Pa 2  and the third portion Pb 1  in the Y-axis direction are W 14 . The width W 13  is larger than the width W 2  in  FIG.  2   , and the width W 14  is smaller than the width W 4  in  FIG.  2   . 
     In the first embodiment, an increase in the channel resistance of the entire nozzle channel Nfa can be prevented by increasing the channel cross-sectional area of the second portion Pa 2  to some extent, but the nozzle channel Nfa locally has high channel resistance. In other words, the channel cross-sectional area of the first portion Pa 1  is as small as W 2 ×W 9 , as shown in  FIG.  7   , which increases the local channel resistance in the first portion Pa 1  to some extent, causing the rate to be limited, possibly exerting an influence on the channel resistance of the entire nozzle channel Nfa. 
     For that reason, in the second embodiment, the width W 13  of the first portion Pa 1  and the fourth portion Pb 2  in the Y-axis direction is increased from that of the first embodiment. This can decrease the channel resistance of the first portion Pa 1  and the fourth portion Pb 2 . 
     However, merely increasing the widths of the first portion Pa 1  and the fourth portion Pb 2  in the Y-axis direction decreases the communication plate  33  between the first portion Pa 1  and the third portion Pb 1 . This is likely to cause structural crosstalk. For that reason, in the second embodiment, the width W 14  of the second portion Pa 2  and the third portion Pb 1  in the Y-axis direction is decreased from the first embodiment so that the thickness of the communication plate  33  between the first portion Pa 1  and the third portion Pb 1  is the same as that of the first embodiment, preventing the occurrence of structural crosstalk. Furthermore, the second portion Pa 2  and the third portion Pb 1  have a large width of W 10  in the Z-axis direction. This configuration does not increase the local channel resistance so much even if the width in the Y-axis direction is as small as W 14 . Thus, the second embodiment can prevent an increase in local channel resistance as compared with the first embodiment. 
     Third Embodiment 
       FIG.  14    is a schematic diagram illustrating a channel structure in a liquid ejecting head  24  according to a third embodiment as viewed in the Z-axis direction.  FIG.  15    is a cross-sectional view taken along line XV-XV in  FIG.  14   .  FIG.  16    is a cross-sectional view taken along line XVI-XVI in  FIG.  14   . Components similar to those of the first and second embodiments are given the same reference signs, and detailed descriptions thereof will be omitted or simplified. 
     The liquid ejecting head  24  of the third embodiment differs from the first embodiment in that the nozzle Na is disposed in the second portion Pa 2  of the individual channel Pa, and the nozzle Nb is disposed in the third portion Pb 1  of the individual channel Pb. 
     In the third embodiment, the individual channels Pa and the individual channels Pb are 180° inverted about the Z-axis, and the nozzle channel Nfa and the nozzle channel Nfb overlap in side view in the Y-axis direction. Thus, the second portion Pa 2  of the individual channel Pa has a portion completely overlapping with the fourth portion Pb 2  and a portion not overlapping therewith in side view, as in the first embodiment. The third portion Pb 1  of the individual channel Pb also has a portion completely overlapping with the first portion Pa 1  and a portion not overlapping in side view. The liquid ejecting head  24  of the third embodiment therefore provides the same operational advantage as in the first embodiment. 
     Fourth Embodiment 
       FIG.  17    is a cross-sectional view taken along line XVII-XVII in  FIG.  14   .  FIG.  18    is a cross-sectional view taken along line XVIII-XVIII in  FIG.  14   . Components similar to those of the first to third embodiments are given the same reference signs, and detailed descriptions thereof will be omitted or simplified. 
     The liquid ejecting head  24  of the fourth embodiment differs from the first embodiment in the configuration of the second portion Pa 2  and the third portion Pb 1 . Specifically, the second portion Pa 2  of the fourth embodiment includes a channel Pa 21  provided in the communication plate  33  and extending in the X-axis direction by a predetermined amount and a channel Pa 22  provided in the nozzle plate  31  and extending in the X-axis direction by a predetermined amount. The channel Pa 22  is provided between the channel Pa 21  and the nozzle Na in the nozzle plate  31  and communicates between the channel Pa 21  and the nozzle Na. Likewise, the third portion Pb 1  of the fourth embodiment includes a channel Pb 11  provided in the communication plate  33  and extending in the X-axis direction by a predetermined amount and a channel Pb 12  provided in the nozzle plate  31  and extending in the X-axis direction by a predetermined amount. The channel Pb 12  is provided between the channel Pall and the nozzle Nb in the nozzle plate  31  and communicates between the channel Pall and the nozzle Nb. 
     The liquid ejecting head  24  of the fourth embodiment has the channel Pa 22  in the nozzle plate  31 , as shown in  FIG.  17   . Assuming that the side on which the pressure chamber Ca 1  and the pressure chamber Ca 2  are positioned in the Z1-direction as viewed from the nozzle channel Nfa is the first side, and the side on which the nozzle Na is positioned in the Z2-direction is the second side, a channel wall surface Sa 7  of the first portion Pa 1  on the second side and a channel wall surface Sa 8  of the second portion Pa 2  on the second side are at different positions in the Z2-direction, and a channel wall surface Sa 5  of the first portion Pa 1  on the first side and a channel wall surface Sa 6  of the second portion Pa 2  on the first side are at the same position in the Z1-direction. In other words, the first portion Pa 1  has the channel wall surface Sa 5  and the channel wall surface Sa. The channel wall surface Sa 7  is positioned between the ink ejection surface of the nozzle Na and the channel wall surface Sa 5  in the Z2-direction. Likewise, the second portion Pa 2  has the channel wall surface Sa 6  and the channel wall surface Sa 8 . The channel wall surface Sa 8  is positioned between the ink ejection surface of the nozzle Na and the channel wall surface Sa 6  in the Z2-direction. 
     Assuming that the side on which the pressure chamber Cb 1  and the pressure chamber Cb 2  are positioned in the Z1-direction as viewed from the nozzle channel Nfb is the first side, and the side on which the nozzle Nb is positioned in the Z2-direction is the second side, a channel wall surface Sb 7  of the third portion Pb 1  on the second side and a channel wall surface Sb 8  of the fourth portion Pb 2  on the second side are at different positions in the Z2-direction, and a channel wall surface Sb 5  of the third portion Pb 1  on the first side and a channel wall surface Sb 6  of the fourth portion Pb 2  on the first side are at the same position in the Z1-direction. In other words, the third portion Pb 1  has the channel wall surface Sb 5  and the channel wall surface Sb 7 . The channel wall surface Sb 7  is positioned between the ink ejection surface of the nozzle Nb and the channel wall surface Sb 5  in the Z2-direction. Likewise, the fourth portion Pb 2  has the channel wall surface Sb 6  and the channel wall surface Sb 8 . The channel wall surface Sb 8  is positioned between the ink ejection surface of the nozzle Nb and the channel wall surface Sb 6  in the Z2-direction. 
     In the fourth embodiment, the individual channels Pa and the individual channels Pb are 180° inverted about the Z-axis, and the nozzle channel Nfa and the nozzle channel Nfb overlap in side view. With this configuration, the channel Pa 21  in the second portion Pa 2  of the individual channel Pa overlaps completely with the fourth portion Pb 2  in side view, and the channel Pa 22  does not overlap with the fourth portion Pb 2  and overlaps entirely with the nozzle plate  31  in side view. Likewise, the channel Pb 11  in the third portion Pb 1  of the individual channel Pb overlaps completely with the first portion Pa 1  in side view, and the channel Pb 12  does not overlap with the first portion Pa 1  but overlaps entirely with the nozzle plate  31  in side view. In other words, the channel Pa 22  is covered with the nozzle plate  31  from three directions, the Z1-direction, the Y1-direction, and the Y2-direction, and the channel Pb 12  is also covered with the nozzle plate  31  from three directions, the Z1-direction, the Y1-direction, and the Y2-direction. The liquid ejecting head  24  of the fourth embodiment therefore provides the same operational advantage as in the first embodiment. 
     Fifth Embodiment 
       FIG.  19    is a cross-sectional view taken along line XIX-XIX in  FIG.  14    according to a fifth embodiment.  FIG.  20    is a cross-sectional view taken along line XX-XX in  FIG.  14    according to the fifth embodiment. The same components as those of the first to fourth embodiments are given the same reference signs, and descriptions thereof will be omitted or simplified. 
     The liquid ejecting head  24  of the fifth embodiment differs from the first embodiment in the configuration of the second portion Pa 2  and the third portion Pb 1 . Specifically, the second portion Pa 2  of the fifth embodiment includes a channel Pa 23  and a channel Pa 24 . The channel Pa 23  is a channel positioned between the first portion Pa 1  and the second communication channel Na 2  in the X-axis direction and extending in the X-axis direction and the Z-axis direction by a predetermined amount. The channel Pa 23  is a channel communicating between the first portion Pa 1  and the second communication channel Na 2 . The channel Pa 24  is provided in the nozzle plate  31  and extends in the X-axis direction by a predetermined amount. The channel Pa 24  is provided between the channel Pa 23  and the nozzle Na in the nozzle plate  31  and communicates between the channel Pa 23  and the nozzle Na. Likewise, the third portion Pb 1  of the fifth embodiment includes a channel Pb 13  and a channel Pb 14 . The channel Pb 13  is a channel positioned between the fourth portion Pb 2  and the third communication channel Nb 1  in the X-axis direction and extending in the X-axis direction and the Z-axis direction by a predetermined amount. The channel Pb 13  is a channel communicating between the fourth portion Pb 2  and the third communication channel Nb 1 . The channel Pb 14  is provided in the nozzle plate  31  and extends in the X-axis direction by a predetermined amount. The channel Pb 14  is provided between the channel Pb 13  and the nozzle Nb in the nozzle plate  31  and communicates between the channel Pb 13  and the nozzle Nb. 
     The width W 10  of the second portion Pa 2  of the fifth embodiment in the Z1-direction is larger than three times the width W 9  of the first portion Pa 1  in the Z1-direction. Likewise, the width W 10  of the third portion Pb 1  of the fifth embodiment is larger than three times the width W 9  of the fourth portion Pb 2 . 
     In the fifth embodiment, the individual channels Pa and the individual channels Pb are 180° inverted about the Z-axis, and the nozzle channel Nfa and the nozzle channel Nfb overlap in side view. Thus, the channel Pa 23  in the second portion Pa 2  of the individual channel Pa has a portion that overlaps completely with the fourth portion Pb 2  in side view and a portion not overlapping therewith, and the channel Pa 24  does not overlap with the fourth portion Pb 2  in side view but overlaps entirely with the nozzle plate  31 . Likewise, the channel Pb 13  in the third portion Pb 1  of the individual channel Pb has a portion that overlaps completely with the first portion Pa 1  in side view and a portion not overlapping therewith, and the channel Pb 14  does not overlap with the first portion Pa 1  in side view but overlaps entirely with the nozzle plate  31 . The liquid ejecting head  24  of the fifth embodiment therefore provides the same operational advantage as in the first embodiment. 
     Sixth Embodiment 
       FIG.  21    is a schematic diagram illustrating a channel structure in a liquid ejecting head  24  according to a sixth embodiment as viewed in the Z-axis direction.  FIG.  22    is a cross section taken along line XXII-XXII in  FIG.  21   .  FIG.  23    is a cross-sectional view taken along line XXIII-XXIII in  FIG.  21   . The same components as those of the first to fifth embodiments are given the same reference signs, and descriptions thereof will be omitted or simplified. 
     The liquid ejecting head  24  of the sixth embodiment differs from the first embodiment in the positions of the nozzle Na and the nozzle Nb. Specifically, the nozzle Na of the sixth embodiment is disposed at the center of the nozzle plate  31  in the X-axis direction, as shown in  FIG.  22   . The nozzle Na is disposed in the vicinity of an end of the first portion Pa 1  in the X1-direction, as shown in  FIG.  22   . Likewise, the nozzle Nb of the sixth embodiment is disposed at the center of the nozzle plate  31  in the X-axis direction, as shown in  FIG.  23   . The nozzle Nb is disposed in the vicinity of an end of the fourth portion Pb 2  in the X2-direction. 
     As shown in  FIG.  21   , the multiple nozzles Na and the multiple nozzles Nb of the sixth embodiment are positioned on the same straight line to constitute a nozzle array L. The nozzle array L is an aggregate of the multiple nozzles Na and the multiple nozzles Nb arrayed on the straight line along the Y-axis. The nozzles Na and the nozzles Nb are positioned at the same position in the X1-direction, as shown in  FIG.  21   . As shown in  FIG.  21   , the nozzles N including the nozzles Na and the nozzles Nb are arrayed at a pitch of θ. The pitch θ is the distance between the center of the nozzle Na and the center of the nozzle Nb in the Y-axis direction. 
     In the sixth embodiment, the individual channels Pa and the individual channels Pb are 180° inverted about the Z-axis, and the nozzle channel Nfa and the nozzle channel Nfb overlap in side view. Thus, the second portion Pa 2  of the individual channel Pa has a portion that overlaps completely with the fourth portion Pb 2  in side view and a portion not overlapping therewith. The third portion Pb 1  of the individual channel Pb has a portion that overlaps completely with the first portion Pa 1  in side view and a portion not overlapping therewith. The liquid ejecting head  24  of the sixth embodiment therefore provides the same operational advantage as in the first embodiment. 
     Seventh Embodiment 
       FIG.  24    is a schematic diagram illustrating a channel structure in a liquid ejecting head  24  according to a seventh embodiment when viewed in the Z-axis direction. As shown in  FIG.  24   , multiple nozzles N (Na and Nb) are formed on a surface of the liquid ejecting head  24  facing the medium  11 . The multiple nozzles N are arrayed along the Y-axis. Ink is ejected from each of the nozzles N in the Z-axis direction. In other words, the Z-axis corresponds to a direction in which ink is ejected from the nozzles N. 
     The nozzles N in the seventh embodiment are divided into a first nozzle array La and a second nozzle array Lb. The first nozzle array La is an aggregate of the multiple nozzles Na arrayed linearly along the Y-axis. Likewise, the second nozzle array Lb is an aggregate of the multiple nozzles Nb arrayed linearly along the Y-axis. The first nozzle array La and the second nozzle array Lb are disposed in parallel in the X-axis, with a space therebetween. The position of each nozzle Na in the Y-axis direction and the position of each nozzle Nb in the Y-axis direction differ. As shown in  FIG.  24   , the nozzles N including the nozzles Na and the nozzles Nb are arrayed at a pitch (cycle) of θ. The pitch θ is the distance between the center of the nozzle Na and the center of the nozzle Nb in the Y-axis direction. 
     As illustrated in  FIG.  24   , the liquid ejecting head  24  includes an individual channel array  25 . The individual channel array  25  is an aggregation of multiple individual channels P (Pa and Pb) corresponding to different nozzles N. Each of the multiple individual channels P is a channel communicating with a nozzle N corresponding to the individual channel P. The individual channels P extend along the X-axis. The individual channel array  25  is constituted by the multiple individual channels P arranged in parallel along the Y-axis. Although, in  FIG.  24   , each individual channels P is a simple straight line, the actual shape of the individual channel P will be described later. 
     Each individual channel P includes a pressure chamber C (Ca or Cb). The pressure chamber C in each individual channel P is a space that stores the ink ejected from the nozzle N communicating with the individual channel P. In other words, the ink is ejected from the nozzle N as the pressure of the ink in the pressure chamber C changes. 
     As illustrated in  FIG.  24   , the liquid ejecting head  24  includes a first common liquid chamber R 1  and a second common liquid chamber R 2 . The first common liquid chamber R 1  and the second common liquid chamber R 2  extend in the Y-axis direction across the entire area in which the multiple nozzles N are distributed. The individual channel array  25  and the nozzles N are located between the first common liquid chamber R 1  and the second common liquid chamber R 2  in plan view. 
     The multiple individual channels P communicate, in common, with the first common liquid chamber R 1 . Specifically, an end E 1  of each individual channel P in the X2-direction is coupled to the first common liquid chamber R 1 . Likewise, the multiple individual channels P communicate, in common, with the second common liquid chamber R 2 . Specifically, an end E 2  of each individual channel P in the X1-direction is coupled to the second common liquid chamber R 2 . As will be understood from the above description, the individual channels P communicate between the first common liquid chamber R 1  and the second common liquid chamber R 2 . This allows the ink supplied from the first common liquid chamber R 1  to the individual channels P to be ejected through the nozzles N corresponding to the individual channels P. Of the ink supplied from the first common liquid chamber R 1  to the individual channels P, the ink that was not ejected from the nozzles N is discharged into the second common liquid chamber R 2 . 
     The liquid ejecting apparatus  100  according to the seventh embodiment includes a circulating mechanism  26 , as shown in  FIG.  24   . The circulating mechanism  26  is a mechanism for circulating the ink discharged from the individual channels P into the second common liquid chamber R 2  back to the first common liquid chamber R 1 . Specifically, the circulating mechanism  26  includes a first supply pump  261 , a second supply pump  262 , a reserve container  263 , a circulation channel  264 , and a supply channel  265 . 
     The first supply pump  261  is a pump that supplies the ink stored in the liquid container  12  to the reserve container  263 . The reserve container  263  is a subtank that temporarily stores the ink supplied from the liquid container  12 . The circulation channel  264  is a channel that communicates between the second common liquid chamber R 2  and the reserve container  263 . The reserve container  263  is supplied with the ink stored in the liquid container  12  by the first supply pump  261  and is also supplied with the ink discharged from the individual channels P into the second common liquid chamber R 2 , through the circulation channel  264 . The second supply pump  262  is a pump that pumps out the ink stored in the reserve container  263 . The ink pumped out by the second supply pump  262  is supplied to the first common liquid chamber R 1  through the supply channel  265 . 
     The individual channels P of the individual channel array  25  include the individual channels Pa and the individual channels Pb. Each of the individual channels Pa is an individual channel P communicating with corresponding one of the nozzles Na in the first nozzle array La. Each of the individual channels Pb is an individual channel P communicating with corresponding one of the nozzles Nb in the second nozzle array Lb. The individual channels Pa and the individual channels Pb are alternately arrayed along the Y-axis. Thus, the individual channels Pa and the individual channels Pb are adjacent to each other in the Y-axis direction. 
     As will be understood from the above description, the multiple pressure chambers Ca for the different nozzles Na of the first nozzle array La are arrayed linearly along the Y-axis. Likewise, the multiple pressure chambers Cb for the different nozzles Nb of the second nozzle array Lb are arrayed linearly along the Y-axis. The array of multiple pressure chambers Ca and the array of multiple pressure chambers Cb are arranged in parallel in the X-axis direction, with a predetermined space therebetween. The positions of the pressure chambers Ca in the Y-axis direction and the positions of the pressure chambers Cb in the Y-axis direction differ. 
     The specific configuration of the liquid ejecting head  24  according to the seventh embodiment will be described in detail hereinbelow.  FIG.  25    is a cross-sectional view taken along line XXV-XXV in  FIG.  24   .  FIG.  26    is a cross-sectional view taken along line XXVI-XXVI in  FIG.  24   .  FIG.  25    illustrates a cross section passing through the individual channel Pa.  FIG.  26    illustrates a cross section passing through the individual channel Pb. 
     As illustrated in  FIGS.  25  and  26   , the liquid ejecting head  24  includes a channel structure  30 , a piezoelectric element  41 , a casing  42 , a protective substrate  43 , and a wiring substrate  44 . The channel structure  30  is a structure in which the first common liquid chamber R 1 , the second common liquid chamber R 2 , the individual channels P, and channels including the nozzles N are formed. 
     The channel structure  30  is a structure in which a nozzle plate  31 , a communication plate  33 , a pressure chamber substrate  34 , and a vibration plate  35  are layered in this order in the Z1-direction. These components constituting the channel structure  30  are produced by processing a silicon monocrystal substrate by, for example, a general processing method for producing a semiconductor. 
     The nozzle plate  31  has the multiple nozzles N formed therein. Each of the nozzles N is a cylindrical through-hole through which the ink is to be passed. The nozzle plate  31  of the seventh embodiment is a plate-like member having a surface Fa 1  positioned in the Z2-direction and a surface Fa 2  positioned in the Z1-direction. 
       FIG.  27    is an enlarged cross-sectional view of any one nozzle N. As illustrated in  FIG.  27   , one nozzle N includes a first section n 1  and a second section n 2 . The first section n 1  is a section of the nozzle N including an opening through which ink is ejected. In other words, the first section n 1  is a section contiguous to the surface Fa 1  of the nozzle plate  31 . The second section n 2  is a section between the first section n 1  and the individual channel P. In other words, the second section n 2  is a section contiguous to the surface Fa 2  of the nozzle plate  31 . The second section n 2  has a larger diameter than that of the first section n 1 . 
     The communication plate  33  shown in  FIGS.  25  and  26    is a plate-like member including a surface Fc 1  positioned in the Z2-direction and a surface Fc 2  positioned in the Z1-direction. 
     The pressure chamber substrate  34  is a plate-like member including a surface Fd 1  positioned in the Z2-direction and a surface Fd 2  positioned in the Z1-direction. The vibration plate  35  is a plate-like member including a surface Fe 1  positioned in the Z2-direction and a surface Fe 2  positioned in the Z1-direction. 
     The components constituting the channel structure  30  are each formed in a rectangular shape that is long in the Y-axis direction and are bonded to each other with, for example, an adhesive. For example, the surface Fa 2  of the nozzle plate  31  is bonded to the surface Fc 1  of the communication plate  33 , and the surface Fc 2  of the communication plate  33  is bonded to the surface Fd 1  of the pressure chamber substrate  34 . The surface Fd 2  of the pressure chamber substrate  34  is bonded to the surface Fe 1  of the vibration plate  35 . 
     The communication plate  33  has a space O 12  and a space O 22 . Each of the space O 12  and the space O 22  is an opening that is long in the Y-axis direction. On the surface Fc 1  of the communication plate  33 , a vibration absorber  361  that closes the space O 12  and a vibration absorber  362  that closes the space O 22  are disposed. The vibration absorber  361  and the vibration absorber  362  are layered members made of an elastic material. 
     The casing  42  is a case for storing ink. The casing  42  is joined to the surface Fc 2  of the communication plate  33 . The casing  42  has a space O 13  communicating with the space O 12  and a space O 23  communicating with the space O 22 . Each of the space O 13  and the space O 23  is a space that is long in the Y-axis direction. The space O 12  and the space O 13  communicate with each other to form the first common liquid chamber R 1 . Likewise, the space O 22  and the space O 23  communicate with each other to form the second common liquid chamber R 2 . The vibration absorber  361  constitutes a wall surface of the first common liquid chamber R 1  and absorbs a pressure change of the ink in the first common liquid chamber R 1 . The vibration absorber  362  constitutes a wall surface of the second common liquid chamber R 2  and absorbs a pressure change of the ink in the second common liquid chamber R 2 . 
     The casing  42  has a supply port  421  and a discharge port  422 . The supply port  421  is a conduit communicating with the first common liquid chamber R 1  and is coupled to the supply channel  265  of the circulating mechanism  26 . The ink pumped out by the second supply pump  262  into the supply channel  265  is supplied to the first common liquid chamber R 1  through the supply port  421 . The discharge port  422  is a conduit communicating with the second common liquid chamber R 2  and is coupled to the circulation channel  264  of the circulating mechanism  26 . The ink in the second common liquid chamber R 2  is supplied to the circulation channel  264  through the discharge port  422 . 
     The pressure chamber substrate  34  has multiple pressure chambers C (Ca and Cb). Each pressure chamber C is a space between the surface Fc 2  of the communication plate  33  and the surface Fe 1  of the vibration plate  35 . The pressure chamber C is long along the X-axis in plan view. 
     The vibration plate  35  is an elastically vibratile plate-like member. The vibration plate  35  is a lamination of, for example, a first layer made of silicon oxide (SiO2) and a second layer made of zirconium oxide (ZrO2). The vibration plate  35  and the pressure chamber substrate  34  may be integrally formed by selectively removing, in the thickness direction, a part of the plate-like member with a predetermined thickness corresponding to the pressure chamber C. The vibration plate may be of a single layer. 
     On the surface Fe 2  of the vibration plate  35 , the piezoelectric elements  41  for the different pressure chambers C are disposed. The piezoelectric elements  41  for the individual pressure chambers C overlap with the pressure chambers C in plan view. Specifically, each piezoelectric element  41  is a lamination of a first electrode and a second electrode facing each other and a piezoelectric layer formed between the electrodes. The piezoelectric element  41  is an energy generating element that ejects the ink in the pressure chamber C through the nozzle N by changing the pressure of the ink in the pressure chamber C. In other words, the piezoelectric element  41  is deformed by receiving a driving signal to vibrate the vibration plate  35 , and the pressure chamber C is expanded and contracted by the vibration of the vibration plate  35 , and the ink is ejected from the nozzles N. The pressure chambers C (Ca and Cb) are each defined as a range of the individual channel P in which the vibration plate  35  is vibrated as the piezoelectric element  41  is deformed. 
     The protective substrate  43  is a plate-like member disposed on the surface Fe 2  of the vibration plate  35 . The protective substrate  43  protects the piezoelectric elements  41  and also reinforces the mechanical strength of the vibration plate  35 . The piezoelectric elements  41  are housed between the protective substrate  43  and the vibration plate  35 . The wiring substrate  44  is disposed on the surface Fe 2  of the vibration plate. The wiring substrate  44  is a surface-mounted component for electrically coupling the control unit  21  and the liquid ejecting head  24  together. Preferable examples of the wiring substrate  44  include a flexible printed circuit (FPC) and a flexible flat cable (FFC). On the wiring substrate  44 , a driving circuit  45  for supplying a driving signal to each piezoelectric element  41  is mounted. 
     Next, the details of the configuration of the individual channels P will be described. The shape of the individual channel Pa and the shape of the individual channel Pb have a rotationally symmetrical relationship about the axis of symmetry parallel to the Z-axis in plan view. 
     As shown in  FIG.  25   , the individual channel Pa includes a supply channel Ra 1 , a pressure chamber Ca 1 , a first communication channel Na 1 , a nozzle channel Nfa, a second communication channel Na 2 , a lateral communication channel Cq 1 , and a discharge channel Ra 2 . The individual channel Pa is a channel in which these elements are integrated and coupled in the above order. 
     The supply channel Ra 1  is a space formed in the communication plate  33 . Specifically, as shown in  FIG.  25   , the supply channel Ra 1  extends from the space O 12  constituting the first common liquid chamber R 1  to the surface Fc 2  of the communication plate  33  along the Z-axis. An end of the supply channel Ra 1  coupled to the space O 12  is the end E 1  of the individual channel Pa. The supply channel Ra 1  is a channel communicating with the pressure chamber Ca 1  to introduce the ink supplied from the first common liquid chamber R 1  into the pressure chamber Ca 1 . The supply channel Ra 1  is an example of “first individual supply channel”. 
     As shown in  FIG.  25   , the first communication channel Na 1  is a space passing through the communication plate  33 . The first communication channel Na 1  is a channel extending along the Z-axis. The first communication channel Na 1  extends in the Z1-direction to communicate between the pressure chamber Ca 1  and the nozzle channel Nfa. The first communication channel Na 1  is a channel that introduces the ink expelled from the pressure chamber Ca 1  into the nozzle channel Nfa. 
     The nozzle channel Nfa is a channel provided in the communication plate  33  and extending in the X-axis direction. As shown in  FIG.  25   , the nozzle channel Nfa is segmented into a first portion Pa 1  and a second portion Pa 2 . The first portion Pa 1  is a channel positioned between the first communication channel Na 1  and the second portion Pa 2  in the X-axis direction and extending in the X-axis direction. The second portion Pa 2  is a channel positioned between the first portion Pa 1  and the second communication channel Na 2  in the X-axis direction and extending in the X-axis direction. The nozzle Na is disposed in the first portion Pa 1 . 
     The width h 1  of the first portion Pa 1  in the Z-axis direction is smaller than the width h 2  of the second portion Pa 2  in the Z-axis direction. The width W 1  of the first portion Pa 1  in the X1-direction is larger than the width W 3  of the second portion Pa 2  in the X1-direction, as shown in  FIG.  25   . 
     The second communication channel Na 2  is a space provided in the communication plate  33 . The second communication channel Na 2  is a channel extending along the Z-axis. The second communication channel Na 2  extends in the Z1-direction to communicate between the lateral communication channel Cq 1  and the nozzle channel Nfa. The second communication channel Na 2  is a channel that introduces the ink supplied from the second portion Pa 2  into the lateral communication channel Cq 1 . 
     The lateral communication channel Cq 1  is a space provided in the communication plate  33 . The lateral communication channel Cq 1  is a long channel extending in the X-axis. The lateral communication channel Cq 1  extends in the X1-direction to communicate between the second communication channel Na 2  and the discharge channel Ra 2 . The lateral communication channel Cq 1  is a channel that introduces the ink introduced from the second communication channel Na 2  into the discharge channel Ra 2 . 
     The discharge channel Ra 2  is a space formed in the communication plate  33 . An end of the discharge channel Ra 2  coupled to the space O 22  is an end E 2  of the individual channel Pa. The discharge channel Ra 2  is a channel communicating with the lateral communication channel Cq 1  to introduce the ink introduced from the lateral communication channel Cq 1  into the second common liquid chamber R 2 . The discharge channel Ra 2  is an example of “first individual discharge channel”. 
     As shown in  FIG.  26   , the individual channels Pb includes a supply channel Rb 1 , a lateral communication channel Cq 2 , a third communication channel Nb 1 , a nozzle channel Nfb, a fourth communication channel Nb 2 , a pressure chamber Cb 1 , and a discharge channel Rb 2 . The individual channel Pb is a channel in which these elements are integrated and coupled in the above order. 
     The supply channel Rb 1  is a space formed in the communication plate  33 . An end of the supply channel Rb 1  coupled to the space O 12  is the end E 1  of the individual channel Pb. The supply channel Rb 1  is a channel communicating with the lateral communication channel Cq 2  to introduce the ink supplied from the first common liquid chamber R 1  into the lateral communication channel Cq 2 . The supply channel Rb 1  is an example of “second individual supply channel”. 
     The lateral communication channel Cq 2  is a space provided in the communication plate  33 . The lateral communication channel Cq 2  is a long channel extending along the X-axis. The lateral communication channel Cq 2  extends in the X1-direction to communicate between the supply channel Rb 1  and the third communication channel Nb 1 . The lateral communication channel Cq 1  is a channel that introduces the ink introduced from the supply channel Rb 1  into the third communication channel Nb 1 . 
     The third communication channel Nb 1  is a space provided in the communication plate  33 , as shown in  FIG.  26   . The third communication channel Nb 1  is a channel extending along the Z-axis. The third communication channel Nb 1  extends in the Z1-direction to communicate between the lateral communication channel Cq 2  and the nozzle channel Nfb. The third communication channel Nb 1  is a channel that introduces the ink introduced from the lateral communication channel Cq 2  into the nozzle channel Nfb. 
     The nozzle channel Nfb is a channel provided in the communication plate  33  and extending in the X-axis direction. As shown in  FIG.  26   , the nozzle channel Nfb is segmented into a third portion Pb 1  and a fourth portion Pb 2 . The third portion Pb 1  is a channel positioned between the third communication channel Nb 1  and the fourth portion Pb 2  in the X-axis direction and extending in the X-axis direction. The fourth portion Pb 2  is a channel positioned between the third portion Pb 1  and the fourth communication channel Nb 2  in the X-axis direction and extending in the X-axis direction. The nozzle Nb is disposed in the fourth portion Pb 2 . 
     The width h 2  of the third portion Pb 1  in the Z-axis direction is larger than the width h 1  of the fourth portion Pb 2  in the Z-axis direction. The width W 5  of the third portion Pb 1  in the X1-direction is smaller than the width W 7  of the fourth portion Pb 2  in the X1-direction, as shown in  FIG.  26   . 
     The fourth communication channel Nb 2  is a space passing through the communication plate  33 . The fourth communication channel Nb 2  is a channel extending along the Z-axis. The fourth communication channel Nb 2  extends in the Z1-direction to communicate between the pressure chamber Cb 1  and the nozzle channel Nfb. The fourth communication channel Nb 2  is a channel that introduces the ink supplied from the nozzle channel Nfb into the pressure chamber Cb 1 . 
     The discharge channel Rb 2  is a space formed in the communication plate  33 . Specifically, as shown in  FIG.  26   , the discharge channel Rb 2  extends from the space O 22  constituting the second common liquid chamber R 2  to the surface Fc 2  of the communication plate  33  along the Z-axis. An end of the discharge channel Rb 2  coupled to the space O 22  is the end E 2  of the individual channel Pb. The discharge channel Rb 2  is a channel communicating with the pressure chamber Cb 1  to introduce the ink expelled from the pressure chamber Cb 1  into the second common liquid chamber R 2 . The discharge channel Rb 2  is an example of “second individual discharge channel”. 
     In  FIGS.  25  and  26   , for the individual channel Pa and the individual channel Pb adjacent to each other, the pressure chamber Ca 1  and the lateral communication channel Cq 1  of the individual channel Pa have no channel at adjacent positions in the Y-axis direction, and the pressure chamber Cb 1  and the lateral communication channel Cq 2  of the individual channel Pb also have no channel at adjacent positions in the Y-axis direction. This configuration reduces the tendency to cause structural crosstalk even if the pitch θ is decreased, as compared with the sixth embodiment. This allows for decreasing the pitch θ to increase the nozzle resolution in the Z-axis direction, allowing recording a high-quality image. Although, in this embodiment, the first communication channel Na 1  and the third communication channel Nb 1  are at the same position in the X-axis direction, the first communication channel Na 1  and the third communication channel Nb 1  may be disposed at different positions. This also applies to the second communication channel Na 2  and the fourth communication channel Nb 2 . Disposing these channels at different positions reduces or eliminates the structural crosstalk between the first communication channel Na 1  and the third communication channel Nb 1  and between the second communication channel Na 2  and the fourth communication channel Nb 2 , allowing the pitch θ to be decreased more. 
     In this embodiment, the nozzle channel Nfa has the first portion Pa 1  with a width that is small in the Z-axis direction and the second portion Pa 2  with a width that is large in the Z-axis direction, as described above. The nozzle channel Nfb also has the third portion Pb 1  with a width that is large in the Z-axis direction and the fourth portion Pb 2  with a width that is small in the Z-axis direction. The nozzle channel Nfa and the nozzle channel Nfb are disposed so that at least part of the first portion Pa 1  and the third portion Pb 1  do not overlap in the X-axis direction. This prevents the occurrence of structural crosstalk while preventing an increase in channel resistance as in the above embodiments. 
     Other Embodiments 
     The configuration of the liquid ejecting head  24  is not limited to the configurations illustrated in the first to seventh embodiments. The liquid ejecting head  24  may have a configuration in which any two or more configurations selected from the configurations illustrated in the first to seventh embodiments are combined such that they do not contradict each other. 
     Modifications 
     Having described the embodiments of the present disclosure, it is to be understood that the present disclosure is not limited to the embodiments and various changes may be made. Specific modifications that can be given to the embodiments will be illustrated hereinbelow. Any modification selected from the following examples may be combined as appropriate such that they do not contradict each other. 
     (1)  FIG.  28    is a schematic diagram illustrating a channel structure in a liquid ejecting head  24  according to a modification as viewed in the Z-axis direction.  FIG.  29    is a cross-sectional view taken along line XXIX-XXIX in  FIG.  28   .  FIG.  30    is a cross-sectional view taken along line XXX-XXX in  FIG.  28   . 
     The configuration of the liquid ejecting head  24  is not limited to the configurations of the above embodiments. For example, the first portion Pa 1  of the nozzle channel Nfa may communicate with the second communication channel Na 2 , and the second portion Pa 2  may communicate with the first communication channel Na 1 . Likewise, the third portion Pb 1  of the nozzle channel Nfb may communicate with the second communication channel Na 2 , and the fourth portion Pb 2  may communicate with the first communication channel Na 1 . 
     (2) The energy generating element that changes the pressure of the ink in the pressure chamber C is not limited to the piezoelectric element  41  illustrated in the above embodiments. For example, the energy generating element may be a heater element that changes the pressure of the ink by generating bubbles in the pressure chamber C by heating. In the configuration in which the heater element is used as the energy generating element, the range of the individual channel P in which bubbles are generated by heating with the heater element is defined as the pressure chamber C. 
     (3) Although the above embodiments illustrate the serial liquid ejecting apparatus  100  in which the transporter  231  fitted with the liquid ejecting head  24  is moved back and forth, the present disclosure is also applicable to a line liquid ejecting apparatus in which multiple nozzles N are distributed across the entire width of the medium  11 . 
     (4) Although the above embodiments illustrate a case in which the width W 1  of the first portion Pa 1  in the X1-direction is larger than the width W 3  of the second portion Pa 2  in the X1-direction, the present disclosure is not limited to the above configuration. In a modification, the width W 1  of the first portion Pa 1  in the X1-direction may be smaller than the width W 3  of the second portion Pa 2  in the X1-direction. The width W 7  of the fourth portion Pb 2  in the X1-direction may be smaller than the width W 5  of the third portion Pb 1  in the X1-direction. In this case, W 1 =W 7  and W 3 =W 5  may hold. If W 1 &gt;W 3  and W 7 &gt;W 5 , as in the above embodiments, the first portion Pa 1  and the fourth portion Pb 2  do not absolutely overlay in the X-axis direction, reducing the influence of structural crosstalk significantly. In contrast, if W 1 &lt;W 3  and W 7 &lt;W 5 , as in this modification, the first portion Pa 1  and the fourth portion Pb 2  overlap partly in the X-axis direction in the center of the nozzle channel Nfa and the center of the nozzle channel Nfb in the X-axis direction, which is more likely to cause the influence of structural crosstalk than the above embodiments. However, the presence of the second portion Pa 2  and the third portion Pb 1  reduces the influence of structural crosstalk as compared with the configuration described with reference to  FIGS.  9  and  10   . Furthermore, in the modification, the distances of the first portion Pa 1  and the fourth portion Pb 2  in the X-axis direction are longer than those in the above embodiments. This configuration reduces the channel resistance as compared with the above embodiments. 
     Supplements 
     The configuration of the liquid ejecting apparatus  100  is not limited to the configurations of the above embodiments. For example, the liquid ejecting apparatus  100  may be a general liquid ejecting apparatus that circulates ink with a configuration other than the configurations of the above embodiments. The liquid ejecting apparatus  100  illustrated in the above embodiments may be employed in apparatuses only for printing and other various apparatuses, such as facsimile machines and copying machines, and the uses of the present disclosure are not particularly limited. The uses of the liquid ejecting apparatus are not limited to printing. For example, liquid ejecting apparatuses that eject solutions of color materials are used as manufacturing apparatuses for forming color filters of display devices, such as liquid-crystal display panels. Liquid ejecting apparatuses that eject a solution of a conductive material are used as manufacturing apparatuses for forming wires and electrodes of wiring substrates. Liquid ejecting apparatuses that eject a solution of an organic substance related to living organisms are used as apparatuses for producing, for example, biochips. 
     The advantageous effects described in this specification are illustrative only and not restrictive. In other words, the present disclosure can provide the above advantageous effects and/or other advantageous effects which are well known to those skilled in the art from the description of the specification. 
     Having described preferred embodiments of the present disclosure in detail with reference to the attached drawings, the present disclosure is not limited to the embodiments. It will be obvious to those skilled in the art that various changes and modifications may be made without departing from the technical spirit and scope of the present disclosure and they therefore belong to the technical scope of the present disclosure. 
     Supplementary Note 
     The following configuration examples are given from the above illustrated embodiments. 
     In the present application, “element A and element B overlap in a specific direction” refers to “at least part of element A and at least part of element B overlap with each other as viewed in the specific direction”. Not the whole of element A and the whole of element B need to overlap with each other. If at least part of element A and at least part of element B overlap, then it is determined that “element A and element B overlap”. 
     A liquid ejecting head according to an aspect (a first aspect) of the present disclosure includes a first pressure chamber that extends in a first direction and that applies pressure to liquid, a second pressure chamber that extends in the first direction and that applies pressure to the liquid, a first nozzle channel that extends in the first direction and that includes a first nozzle that ejects the liquid. a first communication channel that extends in a second direction intersecting the first direction and that communicates between the first pressure chamber and the first nozzle channel, and a second communication channel that extends in the second direction and that communicates between the second pressure chamber and the first nozzle channel, wherein the first nozzle channel includes a first portion including an end of the first nozzle channel and a second portion including another end of the first nozzle channel, and a width of the second portion in the second direction is larger than a width of the first portion in the second direction. According to this aspect, the structural crosstalk can be reduced while an increase in the channel resistance of the first nozzle channel is prevented. 
     A liquid ejecting head according to a specific example of the first aspect (a second aspect) further includes a third pressure chamber that extends in the first direction and that applies pressure to the liquid, a fourth pressure chamber that extends in the first direction and that applies pressure to the liquid, a second nozzle channel that extends in the first direction and that includes a second nozzle that ejects the liquid, a third communication channel that extends in the second direction and that communicates between the third pressure chamber and the second nozzle channel, and a fourth communication channel that extends in the second direction and that communicates between the fourth pressure chamber and the second nozzle channel, wherein the second nozzle channel includes a third portion including an end of the second nozzle channel and a fourth portion including another end of the second nozzle channel, and a width of the fourth portion in the second direction is smaller than a width of the third portion in the second direction. According to this aspect, the structural crosstalk can be reduced while an increase in the channel resistance of the first nozzle channel and the second nozzle channel is prevented. 
     According to a specific example of the second aspect (a third aspect), the first nozzle and the second nozzle are at a same position in the first direction. 
     According to a specific example of the third aspect (a fourth aspect), the first nozzle channel and the second nozzle channel are adjacent to each other in a third direction intersecting the first direction and the second direction. 
     According to a specific example of one of the second to fourth aspects (a fifth aspect), the first portion and the third portion overlap at least partly in the first direction, and the second portion and the fourth portion overlap at least partly in the first direction. According to this aspect, even if a vibration due to ink flow is generated in the third portion, the vibration is less likely to be transmitted to the first portion because the first portion is not present at the position overlapping with the third portion in the third direction, reducing the influence on the ejection from the first nozzle. In other words, structural crosstalk is unlikely to occur. Likewise, since the fourth portion is not present at the position overlapping with the second portion in the third direction, a vibration from the second portion is less likely to be transmitted to the fourth portion, reducing the possibility of structural crosstalk. 
     According to a specific example of the fifth aspect (a sixth aspect), the third portion overlaps entirely with the first portion in the first direction, and the second portion overlaps entirely with the fourth portion in the first direction. 
     According to a specific example of one of the second to sixth aspects (a seventh aspect), the width of the fourth portion in the second direction is equal to the width of the first portion in the second direction. 
     According to a specific example of one of the second to seventh aspects (an eighth aspect), the width of the third portion in the second direction is equal to the width of the second portion in the second direction. 
     According to a specific example of one of the second to eighth aspects (a ninth aspect), a width of the third portion in the first direction is equal to a width of the second portion in the first direction, and a width of the fourth portion in the first direction is equal to a width of the first portion in the first direction. 
     The liquid ejecting head according to a specific example of one of the second to ninth aspects (a tenth aspect) further includes a first individual supply channel that communicates with the first pressure chamber and that supplies the liquid to the first pressure chamber, a second individual supply channel that communicates with the third pressure chamber and that supplies the liquid to the third pressure chamber, a common supply channel that supplies the liquid, in common, to the first individual supply channel and the second individual supply channel, a first individual discharge channel that communicates with the second pressure chamber and that receives the liquid discharged from the second pressure chamber, a second individual discharge channel that communicates with the fourth pressure chamber and that receives the liquid discharged from the fourth pressure chamber, and a common discharge channel that receives the liquid, in common, discharged from the first individual discharge channel and the second individual discharge channel. 
     According to a specific example of the tenth aspect (an eleventh aspect), the first portion communicates with the first communication channel, and the second portion communicates with the second communication channel. 
     According to a specific example of the tenth aspect (a twelfth aspect), the first portion communicates with the second communication channel, and the second portion communicates with the first communication channel. 
     According to a specific example of one of the first to twelfth aspects (a thirteenth aspect), the width of the second portion in the second direction is larger three times the width of the first portion in the second direction. 
     According to a specific example of one of the first to thirteenth aspects (a fourteenth aspect), a width of the second portion in a third direction intersecting the first direction and the second direction is smaller than a width of the first portion in the third direction. 
     According to a specific example of one of the first to fourteenth aspects (a fifteenth aspect), assuming that a side on which the first pressure chamber and the second pressure chamber are positioned in the second direction as viewed from the first nozzle channel is a first side and that a side on which the first nozzle is positioned in the second direction is a second side, a channel wall surface of the first portion on the second side and a channel wall surface of the second portion on the second side are at a same position in the second direction, and a channel wall surface of the first portion on the first side and a channel wall surface of the second portion on the first side are at different positions in the second direction. 
     According to a specific example of one of the first to fourteenth aspects (a sixteenth aspect), assuming that a side on which the first pressure chamber and the second pressure chamber are positioned in the second direction as viewed from the first nozzle channel is a first side and that a side on which the first nozzle is positioned in the second direction is a second side, a channel wall surface of the first portion on the second side and a channel wall surface of the second portion on the second side are at different positions in the second direction, and a channel wall surface of the first portion on the first side and a channel wall surface of the second portion on the first side are at a same position in the second direction. 
     According to a specific example of one of the first to sixteenth aspects (a seventeenth aspect), the width of the second portion in the first direction is smaller than the width of the first portion in the first direction. 
     According to a specific example of one of the first to sixteenth aspects (an eighteenth aspect), the width of the second portion in the first direction is larger than the width of the first portion in the first direction. 
     According to a specific example of one of the first to eighteenth aspects (a nineteenth aspect), the first nozzle is disposed in the first portion. 
     According to a specific example of one of the first to eighteenth aspects (a twentieth aspect), the first nozzle is disposed in the second portion. 
     The liquid ejecting head according to a specific example of one of the first to twentieth aspects (a twenty-first aspect) further includes a first energy generating element that generates energy for applying pressure to the liquid in the first pressure chamber by receiving a drive voltage and a second energy generating element that generates energy for applying pressure to the liquid in the second pressure chamber by receiving a drive voltage. 
     A liquid ejecting apparatus according to an aspect (a twenty-second aspect) of the present disclosure includes the liquid ejecting head according to any one of the first to twenty-first aspects and a control section that controls an ejecting operation of the liquid ejecting head.