Patent Publication Number: US-2022234354-A1

Title: Liquid ejecting head and liquid ejecting apparatus

Description:
The present application is based on, and claims priority from JP Application Serial Number 2021-011737, filed Jan. 28, 2021, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a liquid ejecting head and a liquid ejecting apparatus. 
     2. Related Art 
     A liquid ejecting head provided in a liquid ejecting apparatus, such as a piezoelectric ink jet printer, typically includes a nozzle, a pressure chamber that communicates with the nozzle, and a piezoelectric element that changes pressure in the pressure chamber. 
     As described in, for example, JP-A-2018-103418, an apparatus that enables liquid in a plurality of pressure chambers to be ejected from a single nozzle to address an increase in viscosity of ink, ejection of liquid having a large particle size, or the like is known. 
     In the apparatus described in JP-A-2018-103418, two pressure chambers provided side by side in a direction intersecting an array direction of nozzles communicate with a single nozzle. On the other hand, the configuration may be such that two pressure chambers provided side by side in the array direction of nozzles communicate with a single nozzle. Such a configuration has an advantage, for example, in that the number of common liquid chambers to supply liquid to the two pressure chambers is only one. When such a configuration is simply adopted, however, the pressure in the respective pressure chambers readily escapes to the common liquid chamber, and ejection characteristics thus need to be improved. 
     SUMMARY 
     To address the aforementioned problem, an aspect of a liquid ejecting head according to the disclosure includes a pressure chamber substrate in which a first pressure chamber and a second pressure chamber adjacent to the first pressure chamber in a first direction are provided, a communication plate in which are provided a first communication channel communicating with the first pressure chamber and the second pressure chamber and a first common liquid chamber communicating with the first pressure chamber and the second pressure chamber at positions different from positions at which the first communication channel communicates with the first pressure chamber and the second pressure chamber, and a nozzle substrate in which a first nozzle communicating with the first pressure chamber and the second pressure chamber in common via the first communication channel is provided. A second communication channel communicating with the first common liquid chamber and communicating with the first pressure chamber and the second pressure chamber in common is provided in the pressure chamber substrate or the communication plate. 
     An aspect of a liquid ejecting apparatus according to the disclosure includes the liquid ejecting head according to the aspect described above, and a control section that controls a liquid ejection operation by the liquid ejecting head. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram schematically illustrating a liquid ejecting apparatus according to a first embodiment. 
         FIG. 2  is an illustration of a liquid channel in the liquid ejecting apparatus according to the first embodiment. 
         FIG. 3  is a sectional view of a liquid ejecting head according to the first embodiment. 
         FIG. 4  is a plan view schematically illustrating a channel of the liquid ejecting head illustrated in  FIG. 3 . 
         FIG. 5  is a sectional view along line V-V in  FIG. 4 . 
         FIG. 6  is a sectional view of a liquid ejecting head according to a second embodiment. 
         FIG. 7  is a sectional view of a liquid ejecting head according to a third embodiment. 
         FIG. 8  is a plan view schematically illustrating a channel of the liquid ejecting head illustrated in  FIG. 7 . 
         FIG. 9  is a sectional view of a liquid ejecting head according to a fourth embodiment. 
         FIG. 10  is a plan view schematically illustrating a channel of the liquid ejecting head illustrated in  FIG. 9 . 
         FIG. 11  is a plan view schematically illustrating a channel of a liquid ejecting head according to a fifth embodiment. 
         FIG. 12  is an illustration of a liquid channel in a liquid ejecting apparatus according to a sixth embodiment. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Embodiments according to the disclosure will be described below with reference to the accompanying drawings. Note that, dimensions or scales of sections in the drawings differ from actual ones as appropriate, and some sections may be schematically illustrated for ease of understanding. The scope of the disclosure is not limited to the embodiments as long as there is no description particularly limiting the disclosure in the following description. 
     Note that, for convenience of description, the following description will be given by appropriately using the X-axis, the Y-axis, and the Z-axis, which cross each other. In the following description, a direction extending along the X-axis is an X 1  direction, and a direction opposite to the X 1  direction is an X 2  direction. Similarly, directions opposite to each other along the Y-axis are a Y 1  direction and a Y 2  direction. Directions opposite to each other along the Z-axis are a Z 1  direction and a Z 2  direction. The Y 1  direction or the Y 2  direction is an example of a first direction. The X 1  direction or the X 2  direction is an example of a second direction. The Z 1  direction or the Z 2  direction is an example of a third direction. Viewing in the Z-axis direction is referred to as plan view in some cases. 
     Here, the Z-axis is typically an axis extending in the vertical direction, and the Z 2  direction corresponds to the downward direction in the vertical direction. However, the Z-axis is not necessarily the axis extending in the vertical direction. Moreover, the X-axis, the Y-axis, and the Z-axis are typically orthogonal to each other but are not limited thereto; they may cross each other at an angle in a range of, for example, 80° to 100°. 
     1. First Embodiment 
     1-1. Overall Configuration of Liquid Ejecting Apparatus 
       FIG. 1  is a diagram schematically illustrating a liquid ejecting apparatus  100  according to a first embodiment. The liquid ejecting apparatus  100  is an ink jet printing apparatus that ejects ink, which is an example of a liquid, in the form of liquid droplets onto a medium M. The medium M is typically a printing sheet. Note that the medium M is not limited to a printing paper sheet and may be any printing object made from resin film, fabric, or the like. 
     As illustrated in  FIG. 1 , a liquid container  10  in which ink is stored is attached to the liquid ejecting apparatus  100 . Examples of a specific aspect of the liquid container  10  include a cartridge detachably attached to the liquid ejecting apparatus  100 , a bag-like ink pack formed from a flexible film, and an ink tank that is able to be replenished with ink. Note that any type of ink may be stored in the liquid container  10 . 
     The liquid ejecting apparatus  100  includes a control unit  20 , a transporting mechanism  30 , a moving mechanism  40 , a liquid ejecting head  50 , and a circulating mechanism  60 . 
     The control unit  20  includes, for example, a processing circuit such as a central processing unit (CPU) or a field programmable gate array (FPGA) and a storage circuit such as semiconductor memory and controls operation of the respective elements of the liquid ejecting apparatus  100 . Here, the control unit  20  is an example of a control section and controls an ink ejection operation by the liquid ejecting head  50 . One or more control units  20  may be provided. 
     The transporting mechanism  30  transports the medium M in the Y 2  direction in accordance with control performed by the control unit  20 . The moving mechanism  40  causes the liquid ejecting head  50  to reciprocate in the X 1  direction and the X 2  direction in accordance with control performed by the control unit  20 . In the example illustrated in  FIG. 1 , the moving mechanism  40  includes a substantially box-shaped transporting body  41  referred to as a carriage in which the liquid ejecting head  50  is accommodated and a transporting belt  42  to which the transporting body  41  is fixed. Note that one or two or more liquid ejecting heads  50  are mounted on the transporting body  41 . In addition to the liquid ejecting head  50 , the liquid container  10  described above may be mounted on the transporting body  41 . 
     The liquid ejecting head  50  ejects the ink, which is supplied from the liquid container  10  via the circulating mechanism  60 , from a plurality of nozzles N onto the medium M in the Z 2  direction in accordance with control performed by the control unit  20 . When the ejection is performed in conjunction with transporting of the medium M by the transporting mechanism  30  and reciprocation of the liquid ejecting head  50  by the moving mechanism  40 , an image by ink is formed on a surface of the medium M. 
     The circulating mechanism  60  is a mechanism that supplies the ink to the liquid ejecting head  50  and that collects the ink, which is discharged from the liquid ejecting head  50 , to again supply the ink to the liquid ejecting head  50 . According to such operation of the circulating mechanism  60 , it is possible to suppress increase in viscosity of the ink and reduce air bubbles remaining in the ink. Note that the configuration of the circulating mechanism  60  will be described with reference to  FIG. 2  described below. 
     1-2. Channel of Liquid Ejecting Apparatus 
       FIG. 2  is an illustration of a liquid channel in the liquid ejecting apparatus  100  according to the first embodiment. As illustrated in  FIG. 2 , the liquid ejecting head  50  includes a plurality of nozzles N, a plurality of individual channels P, a first common liquid chamber R 1 , and a second common liquid chamber R 2  and is coupled to the circulating mechanism  60 . 
     The plurality of nozzles N are arranged in the Y-axis direction, and a set of the plurality of nozzles N forms a nozzle row L. Each of the individual channels P communicates with a corresponding one of the plurality of nozzles N. 
     The plurality of individual channels P are provided for the respective nozzles N. Each of the individual channels P includes four pressure chambers C, a nozzle channel Nf, a communication channel Na 1 , which is an example of a first communication channel, a communication channel Na 2 , which is an example of a fourth communication channel, a communication channel Ra 1 , which is an example of a second communication channel, and a communication channel Ra 2 , which is an example of a third communication channel. 
     The plurality of pressure chambers C of the plurality of individual channels P are divided into pressure chambers C, which are arranged in the Y-axis direction and belong to a row L 1 , and pressure chambers C, which are arranged in the Y-axis direction at positions different from those in the row L 1  in the X 1  direction or the X 2  direction and belong to a row L 2 . 
     Here, four pressure chambers C included in each of the individual channels P are two pressure chambers C adjacent to each other of the pressure chambers C belonging to the row L 1  and two pressure chambers C adjacent to each other of the pressure chambers C belonging to the row L 2 . 
     Note that, of two pressure chambers C in each individual channel P which belong to the row L 1 , one pressure chamber C corresponds to a first pressure chamber C_ 1  described later, and the other pressure chamber C corresponds to a second pressure chamber C_ 2  described later. Of two pressure chambers C in each individual channel P which belong to the row L 2 , one pressure chamber C corresponds to a third pressure chamber C_ 3  described later, and the other pressure chamber C corresponds to a fourth pressure chamber C_ 4  described later. 
     Note that, of two pressure chambers C in each individual channel P which belong to the row L 1 , one pressure chamber C adjacent to a second pressure chamber of another individual channel P can also correspond to a fifth pressure chamber C_ 5  described later, and the other pressure chamber C can also correspond to a sixth pressure chamber C_ 6  described later. Of two pressure chambers C in each individual channel P which belong to the row L 2 , one pressure chamber C adjacent to a second pressure chamber of another individual channel P can also correspond to a seventh pressure chamber C_ 7  described later, and the other pressure chamber C can also correspond to an eighth pressure chamber C_ 8  described later. 
     Two pressure chambers C in the row L 1  and two pressure chamber C in the row L 2  in an individual channel P communicate with each other via the nozzle channel Nf, the communication channel Na 1 , and the communication channel Na 2 . The communication channel Na 1  is interposed between the two pressure chambers C in the row L 1  and the nozzle channel Nf. On the other hand, the communication channel Na 2  is interposed between the two pressure chambers C in the row L 2  and the nozzle channel Nf. Each of the nozzle channels Nf includes a nozzle N. In the nozzle channel Nf, the ink is ejected from the nozzle N when the pressure in the two pressure chambers C in the row L 1  described above and the pressure in the two pressure chambers C in the row L 2  described above change. 
     The individual channels P each communicate with the first common liquid chamber R 1  and the second common liquid chamber R 2 . The first common liquid chamber R 1  is coupled to an end in the X 1  direction of each of the individual channels P and communicates with two pressure chambers C in the row L 1  via the communication channel Ra 1  in each of the individual channels P. The ink to be supplied to the individual channels P is stored in the first common liquid chamber R 1 . On the other hand, the second common liquid chamber R 2  is coupled to an end in the X 2  direction of each of the individual channels P and communicates with two pressure chambers C in the row L 2  via the communication channel Ra 2  in each of the individual channels P. The ink discharged from the individual channel P but not ejected is stored in the second common liquid chamber R 2 . 
     The circulating mechanism  60  is coupled to the first common liquid chamber R 1  and the second common liquid chamber R 2 . The circulating mechanism  60  supplies the ink to the first common liquid chamber R 1  and collects the ink, which is discharged from the second common liquid chamber R 2 , to supply the ink again to the first common liquid chamber R 1 . The circulating mechanism  60  includes a first supplying pump  61 , a second supplying pump  62 , a storage container  63 , a collecting channel  64 , and a supplying channel  65 . 
     The first supplying pump  61  is a pump for supplying the ink, which is stored in the liquid container  10 , to the storage container  63 . The storage container  63  is a temporary-storage tank in which the ink supplied from the liquid container  10  is temporarily stored. The collecting channel  64  is a channel that is interposed between the second common liquid chamber R 2  and the storage container  63  and that enables the ink in the second common liquid chamber R 2  to be collected in the storage container  63 . The ink stored in the liquid container  10  is supplied from the first supplying pump  61  to the storage container  63 , and further, the ink discharged from the individual channels P to the second common liquid chamber R 2  is supplied to the storage container  63  via the collecting channel  64 . The second supplying pump  62  is a pump for feeding the ink stored in the storage container  63 . The supplying channel  65  is a channel that is interposed between the first common liquid chamber R 1  and the storage container  63  and that enables the ink in the storage container  63  to be supplied to the first common liquid chamber R 1 . 
     1-3. Overall Configuration of Liquid Ejecting Head 
       FIG. 3  is a sectional view of the liquid ejecting head  50  according to the first embodiment.  FIG. 3  is a sectional view along line III-III in  FIG. 2 . As illustrated in  FIG. 3 , the liquid ejecting head  50  includes a nozzle substrate  51 , a communication plate  52 , a pressure chamber substrate  53 , a vibrating plate  54 , vibration absorbers  551  and  552 , a plurality of piezoelectric elements  56 , a housing  57 , a sealing body  58 , a wiring substrate  59 , and a drive circuit  70 . 
     Here, the pressure chamber substrate  53 , the vibrating plate  54 , the plurality of piezoelectric elements  56 , the housing  57 , and the sealing body  58  are disposed in a region located in the Z 1  direction relative to the communication plate  52 . On the other hand, the nozzle substrate  51 , the vibration absorber  551 , and the vibration absorber  552  are disposed in a region located in the Z 2  direction relative to the communication plate  52 . Of the components of the liquid ejecting head  50  described above, the nozzle substrate  51 , the communication plate  52 , the pressure chamber substrate  53 , and the vibrating plate  54  are stacked in this order in the Z 1  direction. Such a stacked structure includes the first common liquid chamber R 1 , the second common liquid chamber R 2 , the plurality of individual channels P, and the plurality of nozzles N described above. Moreover, the respective components are each schematically a plate member elongated in the Y direction and are bonded to each other with, for example, an adhesive. 
     The plurality of nozzles N are provided in the nozzle substrate  51 . The nozzles N are through holes passing through the nozzle substrate  51  and enable the ink to pass therethrough. The nozzle substrate  51  is manufactured, for example, in such a manner that a silicon monocrystalline substrate is processed by using a semiconductor processing technique. As the silicon monocrystalline substrate, for example, a ( 100 ) silicon monocrystalline substrate is suitably used. 
     A portion of the first common liquid chamber R 1 , a portion of the second common liquid chamber R 2 , and the plurality of individual channels P excluding portions corresponding to the pressure chambers C are provided in the communication plate  52 . That is, of the elements constituting each of the individual channels P, the nozzle channel Nf, the communication channel Na 1 , the communication channel Na 2 , the communication channel Rat, and the communication channel Ra 2  are provided in the communication plate  52 . 
     The portion of the first common liquid chamber R 1  and the portion of the second common liquid chamber R 2  are spaces passing through the communication plate  52 . The vibration absorber  551  and the vibration absorber  552  that close openings corresponding to the spaces are disposed on the surface of the communication plate  52 , which faces the Z 2  direction. 
     The vibration absorber  551  and the vibration absorber  552  are each a layered member formed of an elastic material. The vibration absorber  551  forms a portion of a wall surface of the first common liquid chamber R 1  and absorbs a pressure change in the first common liquid chamber R 1 . Similarly, the vibration absorber  552  forms a portion of a wall surface of the second common liquid chamber R 2  and absorbs a pressure change in the second common liquid chamber R 2 . 
     The nozzle channel Nf is a groove provided on the surface of the communication plate  52 , which faces in the Z 2  direction. Here, the nozzle substrate  51  forms a portion of a wall surface of the nozzle channel Nf. The communication channel Na 1 , the communication channel Na 2 , the communication channel Ra 1 , and the communication channel Ra 2  are spaces passing through the communication plate  52  and are open in the Z 1  direction and the Z 2  direction. The communication plate  52  described above is manufactured, for example, in such a manner that a silicon monocrystalline substrate is processed by using a semiconductor processing technique. As the silicon monocrystalline substrate, for example, a ( 110 ) silicon monocrystalline substrate is suitably used. Note that the nozzle channel Nf, the communication channel Na 1 , the communication channel Na 2 , the communication channel Ra 1 , and the communication channel Ra 2  will be described in detail with reference to  FIGS. 4 and 5  described later. 
     The pressure chambers C of the plurality of individual channels P are provided in the pressure chamber substrate  53 . The respective pressure chambers C pass through the pressure chamber substrate  53  and are voids between the communication plate  52  and the vibrating plate  54 . The pressure chamber substrate  53  is manufactured, for example, in such a manner that a silicon monocrystalline substrate is processed by using a semiconductor processing technique. As the silicon monocrystalline substrate, for example, a ( 110 ) silicon monocrystalline substrate is suitably used. 
     The vibrating plate  54  is a plate member capable of elastically vibrating. The vibrating plate  54  has a layered structure including, for example, a first layer made of silicon oxide (SiO 2 ) and a second layer made of zirconium oxide (ZrO 2 ). Here, another layer made of metal oxide or the like may be interposed between the first layer and the second layer. Note that a portion or the entirety of the vibrating plate  54  may be formed of the same material as the pressure chamber substrate  53  so as to be integrated with the pressure chamber substrate  53 . For example, the vibrating plate  54  and the pressure chamber substrate  53  are able to be formed integrally by a plate member of a given thickness, from which a region corresponding to the pressure chamber C in the thickness direction is selectively removed. Moreover, the vibrating plate  54  may be formed by a single material layer. 
     The plurality of piezoelectric elements  56  corresponding to the pressure chambers C are disposed on the surface of the vibrating plate  54 , which faces in the Z 1  direction. Each of the piezoelectric elements  56  is constituted, for example, by stacking a first electrode and a second electrode that face each other with a piezoelectric layer formed between both the electrodes. The piezoelectric element  56  changes the pressure of the ink in the pressure chamber C to thereby eject the ink in the pressure chamber C from the nozzle N. Upon receiving a drive signal from the drive circuit  70 , the piezoelectric element  56  causes the piezoelectric element  56  to deform and thereby causes the vibrating plate  54  to vibrate. In accordance with the vibration, the pressure chamber C expands or contracts, and the pressure of the ink in the pressure chamber C changes. Note that the piezoelectric element  56  may be provided in common to two pressure chambers C in the row L 1  or the row L 2  in each of the individual channels P. 
     The housing  57  is a casing in which the ink is stored. The housing  57  has a space demarcated by the first common liquid chamber R 1  excluding the portion provided in the communication plate  52  and by the second common liquid chamber R 2  excluding the portion provided in the communication plate  52 . A hole  571  and a hole  572  are provided in the housing  57 . The hole  571  is a pipe, which communicates with the first common liquid chamber R 1 , and is coupled to the supplying channel  65  of the circulating mechanism  60 . Thus, the ink fed from the second supplying pump  62  to the supplying channel  65  is supplied to the first common liquid chamber R 1  via the hole  571 . On the other hand, the hole  572  is a pipe, which communicates with the second common liquid chamber R 2 , and is coupled to the collecting channel  64  of the circulating mechanism  60 . Thus, the ink in the second common liquid chamber R 2  is discharged to the collecting channel  64  via the hole  572 . 
     The sealing body  58  is a structure that protects the plurality of piezoelectric elements  56  and that reinforces the mechanical strength of the pressure chamber substrate  53  and the vibrating plate  54 . The sealing body  58  is bonded to the surface of the vibrating plate  54  with, for example, an adhesive. The sealing body  58  has a recess in which each of the plurality of piezoelectric elements  56  is housed. 
     The wiring substrate  59  is bonded to the surface of the vibrating plate  54 , which faces in the Z 1  direction. The wiring substrate  59  is a mounting component in which a plurality of wires for electrically coupling the control unit  20  and the liquid ejecting head  50  are formed. The wiring substrate  59  is a flexible wiring substrate, such as a flexible printed circuit (FPC) or flexible flat cable (FFC). The drive circuit  70  for driving the piezoelectric elements  56  is mounted on the wiring substrate  59 . The drive circuit  70  supplies a drive signal to each of the piezoelectric elements  56 . 
     In the liquid ejecting head  50  configured as described above, in accordance with the operation of the circulating mechanism  60  described above, the ink flows through the first common liquid chamber R 1 , the communication channel Ra 1 , the pressure chamber C in the row L 1 , the communication channel Na 1 , the nozzle channel Nf, the communication channel Na 2 , the pressure chamber C in the row L 2 , the communication channel Ra 2 , and the second common liquid chamber R 2  in this order. Note that the circulating mechanism  60  operates in any period or at any timing, and whether the circulating mechanism  60  operates in a period or at a timing overlapping a period or timing in or at which the ink is ejected from the nozzle N is optional. 
     When piezoelectric elements  56  corresponding to the two pressure chambers C in the row L 1  and to the two pressure chambers C in the row L 2  in each of the individual channels P are driven at the same time, the pressure in the pressure chambers C changes, and the ink is ejected from the nozzle N in accordance with the change in pressure. In  FIG. 3 , the path and direction of a flow of the ink at this time are indicated by broken lines and arrows. 
     1-4. Channel of Liquid Ejecting Head 
       FIG. 4  is a plan view schematically illustrating the channel of the liquid ejecting head  50  illustrated in  FIG. 3 .  FIG. 5  is a sectional view along line V-V in  FIG. 4 .  FIG. 4  illustrates how the pressure chamber C, the nozzle channel Nf, the communication channel Na 1 , the communication channel Na 2 , the communication channel Ra 1 , the communication channel Ra 2 , the first common liquid chamber R 1 , and the second common liquid chamber R 2  are arranged when the pressure chamber substrate  53  is viewed in the Z 2  direction. Note that  FIG. 4  schematically illustrates shapes of the respective sections of the channel for convenience of description. However, for example, when the channel is formed in such a manner that a silicon monocrystalline substrate is processed by anisotropic etching, a wall surface extending along a crystal plane of the silicon monocrystalline substrate is actually provided in the channel appropriately. 
       FIG. 4  illustrates a first nozzle N_ 1  and a second nozzle N_ 2  as two nozzles N adjacent to each other in the Y 1  direction or the Y 2  direction. In addition,  FIG. 4  illustrates a first nozzle channel Nf_ 1  as a nozzle channel Nf corresponding to the first nozzle N_ 1  and illustrates the first pressure chamber C_ 1 , the second pressure chamber C_ 2 , the third pressure chamber C_ 3 , and the fourth pressure chamber C_ 4  as four pressure chambers C corresponding to the first nozzle N_ 1 .  FIG. 4  illustrates a second nozzle channel Nf_ 2  as a nozzle channel Nf corresponding to the second nozzle N_ 2  and illustrates the fifth pressure chamber C_ 5 , the sixth pressure chamber C_ 6 , the seventh pressure chamber C_ 7 , and the eighth pressure chamber C_ 8  as four pressure chambers C corresponding to the second nozzle N_ 2 . 
     As illustrated in  FIG. 4 , the first pressure chamber C_ 1 , the second pressure chamber C_ 2 , the fifth pressure chamber C_ 5 , and the sixth pressure chamber C_ 6  are arranged in this order in the Y 2  direction. Here, the first pressure chamber C_ 1  and the second pressure chamber C_ 2  are adjacent to each other in the Y 1  direction or the Y 2  direction. The second pressure chamber C_ 2  and the fifth pressure chamber C_ 5  are adjacent to each other in the Y 1  direction or the Y 2  direction. The fifth pressure chamber C_ 5  and the sixth pressure chamber C_ 6  are adjacent to each other in the Y 1  direction or the Y 2  direction. 
     Similarly, the third pressure chamber C_ 3 , the fourth pressure chamber C_ 4 , the seventh pressure chamber C_ 7 , and the eighth pressure chamber C_ 8  are arranged in this order in the Y 2  direction. Note that the third pressure chamber C_ 3  is located in the X 2  direction with respect to the first pressure chamber C_ 1 , and the first pressure chamber C_ 1  and the third pressure chamber C_ 3  are provided side by side in the X 1  direction or the X 2  direction. Similarly, the second pressure chamber C_ 2  and the fourth pressure chamber C_ 4  are provided side by side in the X 1  direction or the X 2  direction. The fifth pressure chamber C_ 5  and the seventh pressure chamber C_ 7  are provided side by side in the X 1  direction or the X 2  direction. The sixth pressure chamber C_ 6  and the eighth pressure chamber C_ 8  are provided side by side in the X 1  direction or the X 2  direction. 
     The communication channel Na 1  includes a first portion Na 11  and a second portion Na 12 . The respective portions are constituted by holes individually passing through the communication plate  52 . In this manner, the communication channel Na 1  is constituted by two channels per nozzle N. 
     Here, in the communication channel Na 1  corresponding to the first nozzle N_ 1 , the first portion Na 11  is interposed between the first pressure chamber C_ 1  and the first nozzle channel Nf_ 1 , and the second portion Na 12  is interposed between the second pressure chamber C_ 2  and the first nozzle channel Nf_ 1 . Similarly, in the communication channel Na 1  corresponding to the second nozzle N_ 2 , the first portion Na 11  is interposed between the fifth pressure chamber C_ 5  and the second nozzle channel Nf_ 2 , and the second portion Na 12  is interposed between the sixth pressure chamber C_ 6  and the second nozzle channel Nf_ 2 . 
     On the other hand, the communication channel Na 2  includes a first portion Na 21  and a second portion Na 22 . The respective portions are constituted by holes individually passing through the communication plate  52 . In this manner, the communication channel Na 2  is constituted by two holes passing through the communication plate  52  per nozzle N. 
     Here, in the communication channel Na 2  corresponding to the first nozzle N_ 1 , the first portion Na 21  is interposed between the third pressure chamber C_ 3  and the first nozzle channel Nf_ 1 , and the second portion Na 22  is interposed between the fourth pressure chamber C_ 4  and the first nozzle channel Nf_ 1 . Similarly, in the communication channel Na 2  corresponding to the second nozzle N_ 2 , the first portion Na 21  is interposed between the seventh pressure chamber C_ 7  and the second nozzle channel Nf_ 2 , and the second portion Na 22  is interposed between the eighth pressure chamber C_ 8  and the second nozzle channel Nf_ 2 . 
     On the other hand, differently from the communication channel Na 1  and the communication channel Na 2 , the communication channel Ra 1  and the communication channel Ra 2  are each constituted by a single hole passing through the communication plate  52  per nozzle N. 
     Here, the communication channel Ra 1  corresponding to the first nozzle N_ 1  is provided in common to the first pressure chamber C_ 1  and the second pressure chamber C_ 2  and interposed between the first and second pressure chambers C_ 1  and C_ 2  and the first common liquid chamber R 1 . Thus, the communication channel Ra 1  corresponding to the first nozzle N_ 1  is open toward the first pressure chamber C_ 1  and the second pressure chamber C_ 2  and toward the first common liquid chamber R 1 . 
     Similarly, the communication channel Ra 1  corresponding to the second nozzle N_ 2  is provided in common to the fifth pressure chamber C_ 5  and the sixth pressure chamber C_ 6  and interposed between the fifth and sixth pressure chambers C_ 5  and C_ 6  and the first common liquid chamber R 1 . Thus, the communication channel Ra 1  corresponding to the second nozzle N_ 2  is open toward the fifth pressure chamber C_ 5  and the sixth pressure chamber C_ 6  and toward the first common liquid chamber R 1 . 
     To transfer the pressure from the pressure chamber C in the row L 1  to the nozzle N efficiently, the communication channel Ra 1  described above is configured such that the pressure is less likely to escape compared with the communication channel Na 1 . Specifically, for example, the channel resistance of the communication channel Ra 1  is higher than the channel resistance of the communication channel Na 1 . Accordingly, a relation of A&lt;B+C is desirably satisfied, where A is a sum of sectional areas of openings of the communication channel Ra 1  opening toward the first pressure chamber C_ 1  and the second pressure chamber C_ 2 , B is a sectional area of an opening of the first portion Na 11  opening toward the first pressure chamber C_ 1 , and C is a sectional area of an opening of the second portion Na 12  opening toward the second pressure chamber C_ 2 . Note that, in the example illustrated in  FIG. 4 , A is represented by W 2 X×W 2 Y×2, and B and C are each represented by W 1 X×W 1 Y. 
     Note that not only a comparison between the openings of the communication channel Ra 1  and the openings of the communication channel Na 1  but also a comparison between the entire region of the communication channel Ra 1  extending in the Z direction and the entire region of the communication channel Na 1  extending in the Z direction are desirably considered for efficiency of the pressure from the pressure chamber C. Here, typically, when a channel is longer or has a smaller sectional area, the channel resistance thereof increases. On the other hand, both the communication channel Ra 1  and the communication channel Na 1  are provided so as to pass through the communication plate  52 , and it is thus difficult for the communication channel Ra 1  and the communication channel Na 1  to differ largely from each other in the lengths thereof. Accordingly, a relation of D&lt;E+F is more desirably satisfied, where D is an average sectional area of the communication channel Ra 1 , E is an average sectional area of the first portion Na 11  of the communication channel Na 1 , and F is an average sectional area of the second portion Na 12  of the communication channel Na 1 . 
     On the other hand, the communication channel Ra 2  corresponding to the first nozzle N_ 1  is provided in common to the third pressure chamber C_ 3  and the fourth pressure chamber C_ 4  and interposed between the third and fourth pressure chambers C_ 3  and C_ 4  and the second common liquid chamber R 2 . Thus, the communication channel Ra 2  corresponding to the first nozzle N_ 1  is open toward the third pressure chamber C_ 3  and the fourth pressure chamber C_ 4  and toward the second common liquid chamber R 2 . 
     Similarly, the communication channel Ra 2  corresponding to the second nozzle N_ 2  is provided in common to the seventh pressure chamber C_ 7  and the eighth pressure chamber C_ 8  and interposed between the seventh and eighth pressure chambers C_ 7  and C_ 8  and the second common liquid chamber R 2 . Thus, the communication channel Ra 2  corresponding to the second nozzle N_ 2  is open toward the seventh pressure chamber C_ 7  and the eighth pressure chamber C_ 8  and toward the second common liquid chamber R 2 . 
     To transfer the pressure from the pressure chamber C in the row L 2  to the nozzle N efficiently, similarly to the communication channel Ra 1  described above, the communication channel Ra 2  described above is configured such that the pressure is less likely to escape compared with the communication channel Na 2 . 
     As described above, the liquid ejecting head  50  includes the pressure chamber substrate  53 , the communication plate  52 , and the nozzle substrate  51 . As described above, the first pressure chamber C_ 1  and the second pressure chamber C_ 2  adjacent to the first pressure chamber C_ 1  in the Y 2  direction, which is an example of the first direction, are provided in the pressure chamber substrate  53 . The communication channel Na 1 , which is an example of the first communication channel, communicating with the first pressure chamber C_ 1  and the second pressure chamber C_ 2  and the first common liquid chamber R 1  communicating with the first pressure chamber C_ 1  and the second pressure chamber C_ 2  at positions different from positions at which the communication channel Na 1  communicates with the first pressure chamber C_ 1  and the second pressure chamber C_ 2  are provided in the communication plate  52 . The first nozzle N_ 1  communicating with the first pressure chamber C_ 1  and the second pressure chamber C_ 2  in common via the communication channel Na 1  is provided in the nozzle substrate  51 . 
     Additionally, the communication channel Ra 1 , which is an example of the second communication channel, communicating with the first common liquid chamber R 1  and communicating with the first pressure chamber C_ 1  and the second pressure chamber C_ 2  in common is provided in the communication plate  52 . 
     According to the liquid ejecting head  50  described above, since the first pressure chamber C_ 1  and the second pressure chamber C_ 2  communicate with the first common liquid chamber R 1  via the common communication channel Ra 1 , the channel resistance of the communication channel Ra 1  readily increases than the channel resistance of the communication channel Na 1  compared with a configuration in which the first pressure chamber C_ 1  and the second pressure chamber C_ 2  each communicate with the first common liquid chamber R 1  via an individual communication channel. Accordingly, it is possible to reduce a degradation in ejection characteristics due to the pressure in each of the first pressure chamber C_ 1  and the second pressure chamber C_ 2  escaping to the first common liquid chamber R 1 . That is, the pressure in each of the first pressure chamber C_ 1  and the second pressure chamber C_ 2  is able to be used efficiently for ejection of the ink from the first nozzle N_ 1 , resulting in improvement of ejection characteristics compared with the related art. 
     On the other hand, in the configuration in which the first pressure chamber C_ 1  and the second pressure chamber C_ 2  each communicate with the first common liquid chamber R 1  via an individual communication channel, a communication plate needs to be formed by highly accurate processing to increase the channel resistance of the individual communication channel. In particular, since pitches of nozzles have become narrower recently, the individual communication channel is further miniaturized, and it is thus difficult to form the individual communication channel. 
     In the present embodiment, as described above, the communication channel Ra 1  is not provided in the pressure chamber substrate  53  but is provided in the communication plate  52 . Thus, the configuration of the pressure chamber substrate  53  is able to be simplified compared with a configuration in which at least a portion of the communication channel Ra 1  is provided in the pressure chamber substrate  53 . As a result, it is possible to enhance flexibility in designing the pressure chamber substrate  53 . 
     As described above, the first pressure chamber C_ 1  and the second pressure chamber C_ 2  each extend in the X 1  direction or the X 2  direction, which is an example of the second direction intersecting the first direction. The communication channel Na 1  extends in the Z 1  direction or the Z 2  direction, which is an example of the third direction intersecting the first direction and the second direction. Thus, it is possible to transfer the pressure from each of the first pressure chamber C_ 1  and the second pressure chamber C_ 2  to the first nozzle N_ 1  via the communication channel Na 1  efficiently compared with a configuration in which the communication channel Na 1  extends in the same plane as the first pressure chamber C_ 1  and the second pressure chamber C_ 2 . 
     Further, as described above, the communication channel Na 1  includes the first portion Na 11  and the second portion Na 12 . The first portion Na 11  is interposed between the first pressure chamber C_ 1  and the first nozzle N_ 1 . The second portion Na 12  is interposed between the second pressure chamber C_ 2  and the first nozzle N_ 1  at a position away from the first portion Na 11 . Such a communication channel Na 1  enables the pressure in each of the first pressure chamber C_ 1  and the second pressure chamber C_ 2  to be transferred to the first nozzle N_ 1  via the communication channel Na 1  efficiently compared with a single channel common to the first pressure chamber C_ 1  and the second pressure chamber C_ 2 . 
     As described above, the first nozzle channel Nf_ 1  having a portion interposed between the first portion Na 11  and the first nozzle N_ 1  and a portion interposed between the second portion Na 12  and the first nozzle N_ 1  is further provided in the communication plate  52 . Thus, it is possible to increase a sectional area of the first nozzle channel Nf_ 1  while achieving a reduction in size of the liquid ejecting head  50  compared with a configuration in which the first nozzle channel Nf_ 1  is provided only in the nozzle substrate  51 . 
     Further, as described above, the first nozzle channel Nf_ 1  extends in a direction intersecting the Y 2  direction. Thus, the first nozzle channel Nf_ 1  is able to be provided along the nozzle substrate  51 . 
     As described above, the relation of A&lt;B+C is desirably satisfied, where A is a sum of sectional areas of the openings of the communication channel Ra 1  opening toward the first pressure chamber C_ 1  and the second pressure chamber C_ 2 , B is a sectional area of the opening of the first portion Na 11  opening toward the first pressure chamber C_ 1 , and C is a sectional area of the opening of the second portion Na 12  opening toward the second pressure chamber C_ 2 . When the relation is satisfied, even when the communication channel Ra 1  and the communication channel Na 1  are equal to each other in the lengths thereof, the channel resistance of the communication channel Ra 1  is able to be made to be higher than the channel resistance of the communication channel Na 1 . Note that the relation of D&lt;E+F is more desirably satisfied. 
     Here, when relations of A&gt;B and A&gt;C are satisfied, high processing accuracy is not required to form the communication channel Ra 1  compared with an instance in which relations of A&lt;B and A&lt;C are satisfied, and the communication channel Ra 1  is thus easily formed. Note that relations of D&gt;E and D&gt;F are more desirably satisfied to easily form the communication channel Ra 1 . 
     On the other hand, when the relations of A&lt;B and A&lt;C are satisfied, it is possible to increase the channel resistance of the communication channel Ra 1  compared with an instance in which the relations of A&gt;B and A&gt;C are satisfied. Note that relations of D&lt;E and D&lt;F are more desirably satisfied to increase the channel resistance of the communication channel Ra 1 . 
     As described above, the fifth pressure chamber C_ 5  adjacent to the second pressure chamber C_ 2  in the Y 2  direction is further provided in the pressure chamber substrate  53 . The second nozzle N_ 2  adjacent to the first nozzle N_ 1  in the Y 2  direction and communicating with the fifth pressure chamber C_ 5  is further provided in the nozzle substrate  51 . Thus, the ink in the fifth pressure chamber C_ 5  is able to be ejected from the second nozzle N_ 2  independently from the ink ejected from the first nozzle N_ 1 . 
     Here, the sixth pressure chamber C_ 6  adjacent to the fifth pressure chamber C_ 5  in the Y 2  direction is further provided in the pressure chamber substrate  53 . The second nozzle N_ 2  communicates with the fifth pressure chamber C_ 5  and the sixth pressure chamber C_ 6  in common. Thus, it is possible to eject the ink from the second nozzle N_ 2  efficiently by using the pressure in each of the fifth pressure chamber C_ 5  and the sixth pressure chamber C_ 6 . 
     As described above, the third pressure chamber C_ 3  and the fourth pressure chamber C_ 4  are further provided in the pressure chamber substrate  53 . The third pressure chamber C_ 3  is disposed at a position different from that of the first pressure chamber C_ 1  in the X 1  direction or the X 2  direction. The fourth pressure chamber C_ 4  is disposed at a position different from that of the second pressure chamber C_ 2  in the X 1  direction or the X 2  direction and is adjacent to the third pressure chamber C_ 3  in the Y 2  direction. Additionally, the second common liquid chamber R 2  disposed at a position different from that of the first common liquid chamber R 1  in the X 1  direction or the X 2  direction and communicating with the third pressure chamber C_ 3  and the fourth pressure chamber C_ 4  is further provided in the communication plate  52 . The first nozzle N_ 1  communicates with not only the first pressure chamber C_ 1  and the second pressure chamber C_ 2  but also the third pressure chamber C_ 3  and the fourth pressure chamber C_ 4  in common. Thus, it is possible to eject the ink from the first nozzle N_ 1  efficiently by using not only the pressure in each of the first pressure chamber C_ 1  and the second pressure chamber C_ 2  but also the pressure in each of the third pressure chamber C_ 3  and the fourth pressure chamber C_ 4 . 
     Here, as described above, the communication channel Ra 2 , which is an example of the third communication channel, communicating with the second common liquid chamber R 2  and communicating with the third pressure chamber C_ 3  and the fourth pressure chamber C_ 4  in common is further provided in the communication plate  52 . Thus, the channel resistance of the communication channel Ra 2  readily increases compared with a configuration in which the third pressure chamber C_ 3  and the fourth pressure chamber C_ 4  each communicate with the second common liquid chamber R 2  via an individual communication channel. As a result, it is possible to reduce a degradation in ejection characteristics due to the pressure in each of the third pressure chamber C_ 3  and the fourth pressure chamber C_ 4  escaping to the second common liquid chamber R 2 . 
     In the present embodiment, as described above, the first common liquid chamber R 1  is a liquid chamber in which the ink to be supplied to the first pressure chamber C_ 1  and the second pressure chamber C_ 2  is stored. Thus, the first common liquid chamber R 1  includes the hole  571  as a supplying port for supplying liquid. On the other hand, the second common liquid chamber R 2  is a liquid chamber in which the ink to be supplied to the third pressure chamber C_ 3  and the fourth pressure chamber C_ 4  is stored. Thus, the second common liquid chamber R 2  includes the hole  572  as a supplying port for supplying the ink. As described above, the circulating mechanism  60  is coupled to the hole  571  and the hole  572  described above. Accordingly, it is possible to suppress viscosity of the ink in the liquid ejecting head  50  from increasing and suppress air bubbles from remaining in the ink channel of the liquid ejecting head  50 . 
     2. Second Embodiment 
     A second embodiment of the disclosure will be described below. In an example of the embodiment below, elements having similar operations and functions to those of the first embodiment will be given the reference numerals used in the description for the first embodiment, and the detailed description thereof will be omitted appropriately. 
       FIG. 6  is a sectional view of a liquid ejecting head  50 A according to the second embodiment. The liquid ejecting head  50 A is similar to the liquid ejecting head  50  of the first embodiment described above except that a shape of the communication channel Ra 1  is different. Note that, although not illustrated, the communication channel Ra 2  has a configuration similar to that of the communication channel Ra 1 . 
     In the present embodiment, as illustrated in  FIG. 6 , the communication channel Ra 1  has a shape that decreases in width in a stepwise manner in the Z 2  direction when viewed in a cross section perpendicular to the X-axis direction. That is, the communication channel Ra 1  includes a portion Ra 11  communicating with the first pressure chamber C_ 1  and the second pressure chamber C_ 2  and a portion Ra 12  interposed between the portion Ra 11  and the first common liquid chamber R 1 . The portion Ra 12  has a width in the Y-axis direction smaller than a width of the portion Ra 11  in the Y-axis direction. In  FIG. 6 , the width of the portion Ra 12  in the Y-axis direction is represented by w 2   y.    
     Note that the shape of the communication channel Ra 1  is not limited to the example illustrated in  FIG. 6 , the communication channel Ra 1  may have three or more portions that differ from each other in width in the Y-axis direction, and the width of the communication channel Ra 1  in the Y-axis direction may be continuously reduced in the Z 2  direction. 
     Similarly to the first embodiment described above, the second embodiment is also able to achieve improvement of ejection characteristics compared with the related art. In the present embodiment, since the width of the communication channel Ra 1  in the Y-axis direction is reduced toward the first common liquid chamber R 1 , there is an advantage in that the channel resistance of the communication channel Ra 1  readily increases compared with a configuration in which the width is not reduced. 
     3. Third Embodiment 
     A third embodiment of the disclosure will be described below. In an example of the embodiment below, elements having similar operations and functions to those of the first embodiment will be given the reference numerals used in the description for the first embodiment, and the detailed description thereof will be omitted appropriately. 
       FIG. 7  is a sectional view of a liquid ejecting head  50 B according to the third embodiment.  FIG. 8  is a plan view schematically illustrating a channel of the liquid ejecting head  50 B illustrated in  FIG. 7 . The liquid ejecting head  50 B is similar to the liquid ejecting head  50  of the first embodiment described above except that a communication plate  52 B is provided instead of the communication plate  52 . The communication plate  52 B is similar to the communication plate  52  except that a shape of the communication channel Ra 1  is different. 
     As illustrated in  FIG. 7 , the communication channel Ra 1  of the present embodiment includes a portion Ra 13  extending in the X-axis direction and a portion Ra 14  extending in the Z-axis direction when viewed in a cross section perpendicular to the Y-axis direction. Here, the portion Ra 14  is interposed between the portion Ra 13  and the first common liquid chamber R 1 . Similarly, the communication channel Ra 2  of the present embodiment includes a portion Ra 23  extending in the X-axis direction and a portion Ra 24  extending in the Z-axis direction when viewed in a cross section perpendicular to the Y-axis direction. Here, the portion Ra 24  is interposed between the portion Ra 23  and the second common liquid chamber R 2 . 
     As illustrated in  FIG. 8 , in the communication channel Ra 1  of the present embodiment, the portion Ra 13  communicates with the first pressure chamber C_ 1  and the second pressure chamber C_ 2 , and the width of the portion Ra 14  in the Y-axis direction is smaller than the width of the portion Ra 13  in the Y-axis direction. Thus, the portion Ra 13  enables the communication channel Ra 1  to communicate with the first pressure chamber C_ 1  and the second pressure chamber C_ 2 , and the portion Ra 14  enables the channel resistance of the communication channel Ra 1  to be higher. Note that, in  FIG. 8 , the width of the portion Ra 14  in the Y-axis direction is represented by w 2   y , and the width of the portion Ra 14  in the X-axis direction is represented by w 2   x.    
     Similarly, in the communication channel Ra 2  of the present embodiment, the portion Ra 23  communicates with the third pressure chamber C_ 3  and the fourth pressure chamber C_ 4 , and the width of the portion Ra 24  in the Y-axis direction is smaller than the width of the portion Ra 23  in the Y-axis direction. Thus, the portion Ra 23  enables the communication channel Ra 2  to communicate with the third pressure chamber C_ 3  and the fourth pressure chamber C_ 4 , and the portion Ra 24  enables the channel resistance of the communication channel Ra 2  to be higher. 
     Similarly to the first embodiment described above, the third embodiment is also able to achieve improvement of ejection characteristics compared with the related art. 
     4. Fourth Embodiment 
     A fourth embodiment of the disclosure will be described below. In an example of the embodiment below, elements having similar operations and functions to those of the first embodiment will be given the reference numerals used in the description for the first embodiment, and the detailed description thereof will be omitted appropriately. 
       FIG. 9  is a sectional view of a liquid ejecting head  50 C according to the fourth embodiment.  FIG. 10  is a plan view schematically illustrating a channel of the liquid ejecting head  50 C illustrated in  FIG. 9 . The liquid ejecting head  50 C is similar to the liquid ejecting head  50  of the first embodiment described above except that a pressure chamber substrate  53 C is provided instead of the pressure chamber substrate  53 . The pressure chamber substrate  53 C is similar to the pressure chamber substrate  53  except that the pressure chamber substrate  53 C has a portion of the communication channel Ra 1  and a portion of the communication channel Ra 2 . 
     As illustrated in  FIG. 9 , the communication channel Ra 1  of the present embodiment includes a portion Ra 15  provided in the pressure chamber substrate  53 C and a portion Ra 16  provided in the communication plate  52 . Similarly, the communication channel Ra 2  of the present embodiment includes a portion Ra 25  provided in the pressure chamber substrate  53 C and a portion Ra 26  provided in the communication plate  52 . 
     As illustrated in  FIG. 10 , in the communication channel Ra 1  of the present embodiment, the minimum width of the portion Ra 15  in the Y-axis direction is smaller than the minimum width of the portion Ra 16  in the Y-axis direction. Thus, the portion Ra 15  enables the channel resistance of the communication channel Ra 1  to be higher. Here, since the portion Ra 15  is provided in the pressure chamber substrate  53 C, the portion Ra 15  and the pressure chamber C are able to be formed collectively in the same processing step. Thus, it is possible to easily position the portion Ra 15  and the pressure chamber C appropriately. Note that, in the present embodiment, the sum A of sectional areas described above is twice a product of W 2 X indicated in  FIG. 10  and W 2 Z indicated in  FIG. 9 . 
     Similarly, in the communication channel Ra 2  of the present embodiment, the minimum width of the portion Ra 25  in the Y-axis direction is smaller than the minimum width of the portion Ra 26  in the Y-axis direction. Thus, the portion Ra 25  enables the channel resistance of the communication channel Ra 2  to be higher. Here, since the portion Ra 25  is provided in the pressure chamber substrate  53 C, the portion Ra 25  and the pressure chamber C are able to be formed collectively in the same processing step. Thus, it is possible to easily position the portion Ra 25  and the pressure chamber C appropriately. 
     Similarly to the first embodiment described above, the fourth embodiment is also able to achieve improvement of ejection characteristics compared with the related art. In the present embodiment, the communication channel Ra 1  and the communication channel Ra 2  are provided in the pressure chamber substrate  53 C. Thus, it is possible to simplify positioning of the communication channel Ra 1 , the communication channel Ra 2 , and the pressure chamber C during manufacturing compared with a configuration in which neither the communication channel Ra 1  nor the communication channel Ra 2  is provided in the pressure chamber substrate  53 C. Note that, although the portion Ra 16  is provided in common to the first pressure chamber C_ 1  and the second pressure chamber C_ 2  in the example illustrated in  FIG. 10 , the portion Ra 16  is not necessarily provided in common to the first pressure chamber C_ 1  and the second pressure chamber C_ 2  and may be provided individually per pressure chamber C. 
     5. Fifth Embodiment 
     A fifth embodiment of the disclosure will be described below. In an example of the embodiment below, elements having similar operations and functions to those of the first embodiment will be given the reference numerals used in the description for the first embodiment, and the detailed description thereof will be omitted appropriately. 
       FIG. 11  is a plan view schematically illustrating a channel of a liquid ejecting head  50 D according to the fifth embodiment. The liquid ejecting head  50 D is similar to the liquid ejecting head  50  of the first embodiment described above except that a communication plate  52 D is provided instead of the communication plate  52 . The communication plate  52 D is similar to the communication plate  52  but differs from the communication plate  52  in shapes of the communication channel Ra 1  and the nozzle channel Nf. 
     The communication channel Ra 1  of the present embodiment is provided in common to three pressure chambers C. In  FIG. 11 , the first pressure chamber C_ 1 , the second pressure chamber C_ 2 , and the fifth pressure chamber C_ 5  are indicated as the three pressure chambers C. Similarly, the communication channel Ra 2  of the present embodiment is provided in common to three pressure chambers C. In  FIG. 11 , the third pressure chamber C_ 3 , the fourth pressure chamber C_ 4 , and the seventh pressure chamber C_ 7  are indicated as the three pressure chambers C. 
     The communication channel Ra 1  of the present embodiment includes a portion Ra 17  communicating with the first pressure chamber C_ 1 , the second pressure chamber C_ 2 , and the fifth pressure chamber C_ 5  and a portion Ra 18  interposed between the portion Ra 17  and the first common liquid chamber R 1 . The portion Ra 17  has a shape extending in the Y-axis direction so as to be provided across the first pressure chamber C_ 1 , the second pressure chamber C_ 2 , and the fifth pressure chamber C_ 5 . Here, the length of the portion Ra 18  in the Y-axis direction is less than the length of the portion Ra 17  in the Y-axis direction. Thus, the portion Ra 17  enables the communication channel Ra 1  to communicate with the first pressure chamber C_ 1 , the second pressure chamber C_ 2 , and the fifth pressure chamber C_ 5 , and the portion Ra 18  enables the channel resistance of the communication channel Ra 1  to be higher. 
     Similarly, the communication channel Ra 2  of the present embodiment includes a portion Ra 27  communicating with the third pressure chamber C_ 3 , the fourth pressure chamber C_ 4 , and the seventh pressure chamber C_ 7  and a portion Ra 28  interposed between the portion Ra 27  and the second common liquid chamber R 2 . The portion Ra 27  has a shape extending in the Y-axis direction so as to be provided across the third pressure chamber C_ 3 , the fourth pressure chamber C_ 4 , and the seventh pressure chamber C_ 7 . Here, the length of the portion Ra 28  in the Y-axis direction is less than the length of the portion Ra 27  in the Y-axis. Thus, the portion Ra 27  enables the communication channel Ra 2  to communicate with the third pressure chamber C_ 3 , the fourth pressure chamber C_ 4 , and the seventh pressure chamber C_ 7 , and the portion Ra 28  enables the channel resistance of the communication channel Ra 2  to be higher. 
     The first nozzle channel Nf_ 1 , which is the nozzle channel Nf of the present embodiment, communicates with the first pressure chamber C_ 1 , the second pressure chamber C_ 2 , and the fifth pressure chamber C_ 5  via the communication channel Na 1 . The communication channel Na 1  of the present embodiment includes the first portion Na 11 , the second portion Na 12 , and a third portion Na 13 . Those portions are constituted by holes individually passing through the communication plate  52 D. In this manner, the communication channel Na 1  is constituted by three channels per nozzle N. Here, the third portion Na 13  is interposed between the fifth pressure chamber C_ 5  and the first nozzle channel Nf_ 1 . 
     Similarly to the first embodiment described above, the fifth embodiment is also able to achieve improvement of ejection characteristics compared with the related art. In the present embodiment, the fifth pressure chamber C_ 5  adjacent to the second pressure chamber C_ 2  in the Y 2  direction is further provided in the pressure chamber substrate  53 . The first nozzle N_ 1  communicates with not only the first pressure chamber C_ 1  and the second pressure chamber C_ 2  but also the fifth pressure chamber C_ 5  in common. Thus, it is possible to eject the ink from the first nozzle N_ 1  efficiently by using not only the pressure in each of the first pressure chamber C_ 1  and the second pressure chamber C_ 2  but also the pressure in the fifth pressure chamber C_ 5 . 
     6. Sixth Embodiment 
     A sixth embodiment of the disclosure will be described below. In an example of the embodiment below, elements having similar operations and functions to those of the first embodiment will be given the reference numerals used in the description for the first embodiment, and the detailed description thereof will be omitted appropriately. 
       FIG. 12  is an illustration of a liquid channel of a liquid ejecting apparatus  100 E according to the sixth embodiment. The liquid ejecting apparatus  100 E is similar to the liquid ejecting apparatus  100  of the first embodiment described above except that the circulating mechanism  60  is omitted. 
     In the present embodiment, as illustrated in  FIG. 12 , the ink in the liquid container  10  is supplied to each of the first common liquid chamber R 1  and the second common liquid chamber R 2 . Note that, although not illustrated, a pump for pressure-feeding the ink to the liquid ejecting head  50  may be provided between the liquid container  10  and the liquid ejecting head  50 . 
     Similarly to the first embodiment described above, the sixth embodiment is also able to achieve improvement of ejection characteristics compared with the related art. Note that, in the present embodiment, the first common liquid chamber R 1  is a liquid chamber in which the ink to be supplied to the first pressure chamber C_ 1  and the second pressure chamber C_ 2  is stored. The second common liquid chamber R 2  is a liquid chamber in which the ink discharged from the third pressure chamber C_ 3  and the fourth pressure chamber C_ 4  is stored. 
     7. Modified Examples 
     The examples of the above embodiments can be variously modified. Specific modified aspects applicable to the embodiments described above will be exemplified below. Note that any two or more aspects selected from the following exemplification can be appropriately combined within a range in which they do not contradict each other. 
     7-1. Modified Example 1 
     The components in each of the individual channels P are formed symmetrically in the Y 1  direction or the Y 2  direction in each of the embodiments described above, but the disclosure is not limited thereto, and the components in each of the individual channels P may be formed asymmetrically in the Y 1  direction or the Y 2  direction. 
     7-2. Modified Example 2 
     The configuration including the pressure chambers in the row L 1  and the pressure chambers C in the row L 2  is exemplified in each of the embodiments described above, but the disclosure is not limited thereto, and either the pressure chambers C in the row L 1  or the pressure chambers C in the row L 2  and components related thereto may be omitted. 
     7-3. Modified Example 3 
     The configuration in which the number of pressure chambers C included in each of the individual channels P is four or six is exemplified in each of the embodiments described above, but the disclosure is not limited thereto, and the number may be any number as long as the first pressure chamber C_ 1  and the second pressure chamber C_ 2  are included. 
     7-4. Modified Example 4 
     The liquid ejecting apparatus  100  of a serial type in which the transporting body  41  on which the liquid ejecting head  50  is mounted is reciprocated is exemplified in each of the embodiments described above, but the disclosure is applicable to a liquid ejecting apparatus of a line type in which a plurality of nozzles N are distributed over the entire width of the medium M. 
     7-5. Modified Example 5 
     The liquid ejecting apparatus  100  exemplified in each of the embodiments described above can be adopted for various kinds of equipment, such as a facsimile apparatus and a copying machine, in addition to equipment dedicated to printing. The liquid ejecting apparatus of the disclosure is not limited to being used for printing. For example, a liquid ejecting apparatus that ejects a solution of a color material is used as a manufacturing apparatus that forms a color filter of a liquid crystal display device. Further, a liquid ejecting apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus that forms a wire and an electrode of a wiring substrate.