Patent Publication Number: US-11654681-B2

Title: Liquid ejecting head and liquid ejecting apparatus

Description:
The present application is based on, and claims priority from JP Application Serial Number 2020-013350, filed Jan. 30, 2020, 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 
     As described in JP-A-2017-013390, techniques of a liquid ejecting head that ejects liquid in a pressure chamber from a nozzle have been known in the related art. 
     According to the techniques in the related art, however, there is a possibility that air bubbles remain in a channel that extends from the pressure chamber to the nozzle and that an ejection abnormality that makes it difficult for liquid to be ejected from the nozzle occurs. 
     SUMMARY 
     To cope with the aforementioned problem, a liquid ejecting head according to a suitable aspect of the disclosure includes: a first pressure chamber that extends in a first direction and applies pressure to a liquid; a second pressure chamber that extends in the first direction and applies pressure to the liquid; a nozzle channel that extends in the first direction and communicates with a nozzle for ejecting the liquid; a first communication channel that extends in a second direction crossing the first direction and causes the first pressure chamber to communicate with the nozzle channel; and a second communication channel that extends in the second direction and causes the second pressure chamber to communicate with the nozzle channel, in which wall surfaces of the nozzle channel include a first wall surface which extends in the first direction and in which the nozzle is provided and a second wall surface which extends in the first direction and is opposite to the first wall surface, wall surfaces of the first communication channel include a third wall surface which extends in the second direction and a distance from which to the nozzle in the first direction is longest and a fourth wall surface which extends in the second direction and is opposite to the third wall surface, and a fifth wall surface which extends in a third direction set between the first direction and the second direction is provided between the second wall surface and the fourth wall surface. 
     A liquid ejecting apparatus according to a suitable aspect of the disclosure includes: a first pressure chamber that extends in a first direction and applies pressure to a liquid; a second pressure chamber that extends in the first direction and applies pressure to the liquid; a nozzle channel that extends in the first direction and communicates with a nozzle for ejecting the liquid; a first communication channel that extends in a second direction crossing the first direction and causes the first pressure chamber to communicate with the nozzle channel; and a second communication channel that extends in the second direction and causes the second pressure chamber to communicate with the nozzle channel, in which wall surfaces of the nozzle channel include a first wall surface which extends in the first direction and in which the nozzle is provided and a second wall surface which extends in the first direction and is opposite to the first wall surface, wall surfaces of the first communication channel include a third wall surface which extends in the second direction and a distance from which to the nozzle in the first direction is longest and a fourth wall surface which extends in the second direction and is opposite to the third wall surface, and a fifth wall surface which extends in a third direction set between the first direction and the second direction is provided between the second wall surface and the fourth wall surface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a configuration diagram illustrating an example of a liquid ejecting apparatus according to an embodiment of the disclosure. 
         FIG.  2    is an exploded perspective view illustrating an example of a configuration of a liquid ejecting head. 
         FIG.  3    is a sectional view illustrating an example of the configuration of the liquid ejecting head. 
         FIG.  4    is a sectional view illustrating an example of a configuration of a piezoelectric element. 
         FIG.  5    is a sectional view illustrating an example of the configuration of the liquid ejecting head. 
         FIG.  6    is a view for explaining an example of the flow rate of ink in a circulation channel. 
         FIG.  7    is a sectional view illustrating an example of a configuration of a liquid ejecting head according to a reference example. 
         FIG.  8    is a view for explaining an example of the flow rate of ink in a circulation channel according to the reference example. 
         FIG.  9    is a sectional view illustrating an example of a configuration of a liquid ejecting head according to Modification 1. 
         FIG.  10    is an exploded perspective view illustrating an example of a configuration of a liquid ejecting head according to Modification 2. 
         FIG.  11    is a plan view illustrating an example of the configuration of the liquid ejecting head according to Modification 2. 
         FIG.  12    is a sectional view illustrating an example of the configuration of the liquid ejecting head according to Modification 2. 
         FIG.  13    is a sectional view illustrating an example of the configuration of the liquid ejecting head according to Modification 2. 
         FIG.  14    is a sectional view illustrating an example of the configuration of the liquid ejecting head according to Modification 2. 
         FIG.  15    is a sectional view illustrating an example of the configuration of the liquid ejecting head according to Modification 2. 
         FIG.  16    is a configuration diagram illustrating an example of a liquid ejecting apparatus according to Modification 3. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     An embodiment of the disclosure will be described below with reference to the drawings. Note that, in the drawings, dimensions and scales of components appropriately differ from actual ones. Since the embodiment described below is a preferred specific example of the disclosure, various limitations that are desirable from a technical viewpoint are added. However, the scope of the disclosure is not limited to the embodiment as long as there is no description particularly limiting the disclosure in the following description. 
     A. Embodiment 
     A liquid ejecting apparatus  100  according to the present embodiment will be described below with reference to  FIG.  1   . 
     1. Outline of Liquid Ejecting Apparatus 
       FIG.  1    is a view for explaining an example of the liquid ejecting apparatus  100  according to the present embodiment. The liquid ejecting apparatus  100  according to the present embodiment is an ink jet printing apparatus that ejects ink onto a medium PP. Although the medium PP is typically a printing sheet, any printing object made from a resin film, fabric, or the like can be used as the medium PP. 
     As illustrated in  FIG.  1   , the liquid ejecting apparatus  100  includes a liquid container  93  that accumulates ink. As the liquid container  93 , for example, a cartridge detachably attachable to the liquid ejecting apparatus  100 , a bag-like ink pack formed from a flexible film, or an ink tank that is able to be replenished with ink is able to be adopted. The liquid container  93  accumulates a plurality of types of inks of different colors. 
     As illustrated in  FIG.  1   , the liquid ejecting apparatus  100  includes a control device  90 , a moving mechanism  91 , a transport mechanism  92 , and a circulation mechanism  94 . 
     Among these, the control device  90  includes, for example, a processing circuit such as a CPU or FPGA and a storage circuit such as semiconductor memory and controls respective elements of the liquid ejecting apparatus  100 . Here, “CPU” is an abbreviation for central processing unit and “FPGA” is an abbreviation for field programmable gate array. 
     The moving mechanism  91  transports the medium PP in the +Y direction in accordance with control of the control device  90 . Note that, in the following description, the +Y direction and the −Y direction, which is opposite to the +Y direction, are collectively referred to as the Y-axis direction. 
     The transport mechanism  92  causes a plurality of liquid ejecting heads  1  to reciprocate in the +X direction and the −X direction, which is opposite to the +X direction, in accordance with control of the control device  90 . Note that, in the following description, the +X direction and the −X direction are collectively referred to as the X-axis direction. Here, the +X direction is a direction crossing the +Y direction. The +X direction is typically a direction orthogonal to the +Y direction. The transport mechanism  92  includes a storage case  921  that stores the plurality of liquid ejecting heads  1  and an endless belt  922  to which the storage case  921  is fixed. Note that the liquid container  93  may be stored in the storage case  921  together with the liquid ejecting heads  1 . 
     The circulation mechanism  94  supplies the ink, which is accumulated in the liquid container  93 , to a supply channel RB 1  provided in a liquid ejecting head  1  in accordance with control of the control device  90 . Further, in accordance with control of the control device  90 , the circulation mechanism  94  collects ink accumulated in a discharge channel RB 2  provided in the liquid ejecting head  1  and causes the collected ink to return to the supply channel RB 1 . Note that the supply channel RB 1  and the discharge channel RB 2  will be described later with reference to  FIG.  3   . 
     As illustrated in  FIG.  1   , a driving signal Com for driving the liquid ejecting head  1  and a control signal SI for controlling the liquid ejecting head  1  are supplied from the control device  90  to the liquid ejecting head  1 . Then, in accordance with control with the control signal SI, the liquid ejecting head  1  is driven with the driving signal Com to eject the ink in the +Z direction from a portion of or all M nozzles N provided in the liquid ejecting head  1 . Here, a value of M is a natural number of 1 or more. The +Z direction is a direction crossing the +X direction and the +Y direction. The +Z direction is typically a direction orthogonal to the +X direction and the +Y direction. In the following description, the +Z direction and the −Z direction, which is opposite to the +Z direction, are collectively referred to as the Z-axis direction in some cases. Note that the nozzles N will be described later with reference to  FIGS.  2  and  3   . 
     In conjunction with transport of the medium PP by the moving mechanism  91  and reciprocation of the liquid ejecting head  1  by the transport mechanism  92 , the liquid ejecting head  1  ejects the ink from a portion of or all the M nozzles N and causes the ejected ink to be deposited on the surface of the medium PP to thereby form a desired image on the surface of the medium PP. 
     2. Outline of Liquid Ejecting Head 
     An outline of the liquid ejecting head  1  will be described below with reference to  FIGS.  2  to  4   . 
     Note that  FIG.  2    is an exploded perspective view of the liquid ejecting head  1 , and  FIG.  3    is a sectional view along line III-III in  FIG.  2   . 
     As illustrated in  FIGS.  2  and  3   , the liquid ejecting head  1  includes a nozzle substrate  60 , a compliance sheet  61 , a compliance sheet  62 , a communication plate  2 , a pressure chamber substrate  3 , a vibrating plate  4 , an accumulation chamber forming substrate  5 , and a wiring substrate  8 . 
     As illustrated in  FIG.  2   , the nozzle substrate  60  is a plate member, which is elongated in the Y-axis direction and extends substantially parallel to the XY plane, and has the M nozzles N formed therein. Here, the term “substantially parallel” includes not only a case of being exactly parallel but also a case of being regarded as parallel within a tolerance. The nozzle substrate  60  is manufactured, for example, in such a manner that a silicon monocrystalline substrate is processed by using a semiconductor manufacturing technique such as etching. Note that any known material and process can be adopted to manufacture the nozzle substrate  60 . The nozzles N are through holes provided in the nozzle substrate  60 . In the present embodiment, for example, a case where the M nozzles N are provided in the nozzle substrate  60  so as to form a nozzle row Ln that extends in the Y-axis direction is assumed. 
     As illustrated in  FIGS.  2  and  3   , the communication plate  2  is provided on the −Z side of the nozzle substrate  60 . The communication plate  2  is a plate member, which is elongated in the Y-axis direction and extends substantially parallel to the XY plane, and has an ink channel formed therein. 
     Specifically, one supply channel RA 1  and one discharge channel RA 2  are formed in the communication plate  2 . Of the supply channel RA 1  and the discharge channel RA 2 , the supply channel RA 1  communicates with the supply channel RB 1  described later and is provided so as to extend in the Y-axis direction. The discharge channel RA 2  communicates with the discharge channel RB 2  described later and is provided, in the −X direction as viewed from the supply channel RA 1 , so as to extend in the Y-axis direction. 
     In the communication plate  2 , M coupling channels RK 1  corresponding on a one-to-one basis to the M nozzles N, M coupling channels RK 2  corresponding on a one-to-one basis to the M nozzles N, M communication channels RR 1  corresponding on a one-to-one basis to the M nozzles N, M communication channels RR 2  corresponding on a one-to-one basis to the M nozzles N, and M nozzle channels RN corresponding on a one-to-one basis to the M nozzles N are formed. Among these, a coupling channel RK 1  communicates with the supply channel RA 1  and is provided, in the −X direction as viewed from the supply channel RA 1 , so as to extend in the Z-axis direction. A communication channel RR 1  is provided, in the −X direction as viewed from the coupling channel RK 1 , so as to extend in the Z-axis direction. A coupling channel RK 2  communicates with the discharge channel RA 2  and is provided, in the +X direction as viewed from the discharge channel RA 2 , so as to extend in the Z-axis direction. A communication channel RR 2  is provided, in the +X direction as viewed from the coupling channel RK 2  and in the −X direction as viewed from the communication channel RR 1 , so as to extend in the Z axis direction. A nozzle channel RN communicates with the communication channel RR 1  and the communication channel RR 2  and is provided, in the −X direction as viewed from the communication channel RR 1  and in the +X direction as viewed from the communication channel RR 2 , so as to extend in the X-axis direction. The nozzle channel RN communicates with a nozzle N corresponding to the nozzle channel RN. 
     Note that the communication plate  2  is manufactured, for example, in such a manner that a silicon monocrystalline substrate is processed by using a semiconductor manufacturing technique. Note that any known material and process can be adopted to manufacture the communication plate  2 . 
     As illustrated in  FIGS.  2  and  3   , the pressure chamber substrate  3  is provided on the −Z side of the communication plate  2 . The pressure chamber substrate  3  is a plate member, which is elongated in the Y-axis direction and extends substantially parallel to the XY plane, and has an ink channel formed therein. 
     Specifically, in the pressure chamber substrate  3 , M pressure chambers CB 1  corresponding on a one-to-one basis to the M nozzles N and M pressure chambers CB 2  corresponding on a one-to-one basis to the M nozzles N are formed. Among these, a pressure chamber CB 1  communicates with the coupling channel RK 1  and the communication channel RR 1  and is provided, as viewed in the Z-axis direction, so as to couple an end of the coupling channel RK 1  on the +X side and an end of the communication channel RR 1  on the −X side and extend in the X-axis direction. A pressure chamber CB 2  communicates with the coupling channel RK 2  and the communication channel RR 2  and is provided, as viewed in the Z-axis direction, so as to couple an end of the coupling channel RK 2  on the −X side and an end of the communication channel RR 2  on the +X side and extend in the X-axis direction. 
     Note that the pressure chamber substrate  3  is manufactured, for example, in such a manner that a silicon monocrystalline substrate is processed by using a semiconductor manufacturing technique. Note that any known material and process can be adopted to manufacture the pressure chamber substrate  3 . 
     Note that, in the following description, an ink channel that causes the supply channel RA 1  and the discharge channel RA 2  to communicate with each other is referred to as a circulation channel RJ. That is, M circulation channels RJ corresponding on a one-to-one basis to the M nozzles N cause the supply channel RA 1  and the discharge channel RA 2  to communicate with each other. Each of the circulation channels RJ includes the coupling channel RK 1  that communicates with the supply channel RA 1 , the pressure chamber CB 1  that communicates with the coupling channel RK 1 , the communication channel RR 1  that communicates with the pressure chamber CB 1 , the nozzle channel RN that communicates with the communication channel RR 1 , the communication channel RR 2  that communicates with the nozzle channel RN, the pressure chamber CB 2  that communicates with the communication channel RR 2 , and the coupling channel RK 2  that causes the pressure chamber CB 2  and the discharge channel RA 2  to communicate with each other, as described above. 
     As illustrated in  FIGS.  2  and  3   , the vibrating plate  4  is provided on the −Z side of the pressure chamber substrate  3 . The vibrating plate  4  is a plate member, which is elongated in the Y-axis direction and extends substantially parallel to the XY plane, and is a member capable of elastically vibrating. 
     As illustrated in  FIGS.  2  and  3   , M piezoelectric elements PZ 1  corresponding on a one-to-one basis to the M pressure chambers CB 1  and M piezoelectric elements PZ 2  corresponding on a one-to-one basis to the M pressure chambers CB 2  are provided on the −Z side of the vibrating plate  4 . In the following description, a piezoelectric element PZ 1  and a piezoelectric element PZ 2  are collectively referred to as a piezoelectric element PZq. The piezoelectric element PZq is a passive element that is deformed in accordance with a change in the potential of the driving signal Com. In other words, the piezoelectric element PZq is an example of an energy conversion element that converts electrical energy of the driving signal Com into kinetic energy. Note that, in the following description, components and signals of the liquid ejecting head  1 , which correspond to the piezoelectric element PZq, are sometimes suffixed with “q”. 
       FIG.  4    is an enlarged sectional view of the vicinity of the piezoelectric element PZq. 
     As illustrated in  FIG.  4   , the piezoelectric element PZq is a layered structure in which a piezoelectric material ZMq is interposed between a lower electrode ZDq to which a given reference potential VBS is supplied and an upper electrode ZUq to which the driving signal Com is supplied. The piezoelectric element PZq is, for example, a portion in which the lower electrode ZDq, the upper electrode ZUq, and the piezoelectric material ZMq overlap each other as viewed in the −Z direction. Moreover, a pressure chamber CBq is provided in the +Z direction of the piezoelectric element PZq. 
     As described above, the piezoelectric element PZq is driven and deformed in accordance with the change in the potential of the driving signal Com. The vibrating plate  4  vibrates with the deformation of the piezoelectric element PZq. When the vibrating plate  4  vibrates, the pressure in the pressure chamber CBq changes. The change in the pressure in the pressure chamber CBq causes the ink filled in the pressure chamber CBq to be ejected from the nozzle N via a communication channel RRq and the nozzle channel RN. 
     As illustrated in  FIGS.  2  and  3   , the wiring substrate  8  is mounted on the surface of the vibrating plate  4  on the −Z side. The wiring substrate  8  is a part for electrically coupling the control device  90  and the liquid ejecting head  1 . As the wiring substrate  8 , for example, a flexible wiring substrate such as an FPC or FFC is suitably adopted. Here, “FPC” is an abbreviation for flexible printed circuit, and “FFC” is an abbreviation for flexible flat cable. A drive circuit  81  is mounted on the wiring substrate  8 . The drive circuit  81  is an electrical circuit that switches between supplying and not supplying the driving signal Com to the piezoelectric element PZq in accordance with control with the control signal SI. As illustrated in  FIG.  4   , the drive circuit  81  supplies the driving signal Com to the upper electrode ZUq of the piezoelectric element PZq via a wire  810 . 
     Note that, in the following description, the driving signal Com supplied to the piezoelectric element PZ 1  is sometimes referred to as a driving signal Com 1 , and the driving signal Com supplied to the piezoelectric element PZ 2  is sometime referred to as a driving signal Com 2 . In the present embodiment, a case in which a waveform of the driving signal Com 1  supplied from the drive circuit  81  to the piezoelectric element PZ 1  corresponding to the nozzle N and a waveform of the driving signal Com 2  supplied from the drive circuit  81  to the piezoelectric element PZ 2  corresponding to the nozzle N are substantially identical when the ink is ejected from the nozzle N is assumed. Here, the term “substantially identical” includes not only a case of being exactly identical but also a case of being regarded as identical within a tolerance. 
     As illustrated in  FIGS.  2  and  3   , the accumulation chamber forming substrate  5  is provided on the −Z side of the communication plate  2 . The accumulation chamber forming substrate  5  is a member, which is elongated in the Y-axis direction, and has an ink channel formed therein. 
     Specifically, one supply channel RB 1  and one discharge channel RB 2  are formed in the accumulation chamber forming substrate  5 . Of the supply channel RB 1  and the discharge channel RB 2 , the supply channel RB 1  communicates with the supply channel RA 1  and is provided, in the −Z direction as viewed from the supply channel RA 1 , so as to extend in the Y-axis direction. The discharge channel RB 2  communicates with the discharge channel RA 2  and is provided, in the −Z direction as viewed from the discharge channel RA 2  and in the −X direction as viewed from the supply channel RB 1 , so as to extend in the Y-axis direction. 
     Further, an inlet port  51  that communicates with the supply channel RB 1  and a discharge port  52  that communicates with the discharge channel RB 2  are provided in the accumulation chamber forming substrate  5 . The ink is supplied from the liquid container  93  to the supply channel RB 1  via the inlet port  51 . The ink accumulated in the discharge channel RB 2  is collected via the discharge port  52 . 
     An opening  50  is provided in the accumulation chamber forming substrate  5 . The pressure chamber substrate  3 , the vibrating plate  4 , and the wiring substrate  8  are provided inside the opening  50 . 
     Note that the accumulation chamber forming substrate  5  is formed, for example, by injection molding of a resin material. Note that any known material and process can be adopted to manufacture the accumulation chamber forming substrate  5 . 
     In the present embodiment, the ink supplied from the liquid container  93  to the inlet port  51  flows to the supply channel RA 1  via the supply channel RB 1 . Then, a portion of the ink flowing into the supply channel RA 1  flows into the pressure chamber CB 1  via the coupling channel RK 1 . A portion of the ink flowing into the pressure chamber CB 1  flows into the pressure chamber CB 2  via the communication channel RR 1 , the nozzle channel RN, and the communication channel RR 2 . Then, a portion of the ink flowing into the pressure chamber CB 2  is discharged from the discharge port  52  via the coupling channel RK 2 , the discharge channel RA 2 , and the discharge channel RB 2 . 
     Note that, when the piezoelectric element PZ 1  is driven with the driving signal Com 1 , a portion of the ink filled in the pressure chamber CB 1  is ejected from the nozzle N via the communication channel RR 1  and the nozzle channel RN. When the piezoelectric element PZ 2  is driven with the driving signal Com 2 , a portion of the ink filled in the pressure chamber CB 2  is ejected from the nozzle N via the communication channel RR 2  and the nozzle channel RN. 
     As illustrated in  FIGS.  2  and  3   , the compliance sheet  61  is provided on the surface of the communication plate  2  on the +Z side so as to block the supply channel RA 1  and the coupling channel RK 1 . The compliance sheet  61  is formed of an elastic material and absorbs a change in the pressure of the ink in the supply channel RA 1  and the coupling channel RK 1 . Additionally, the compliance sheet  62  is provided on the surface of the communication plate  2  on the +Z side so as to block the discharge channel RA 2  and the coupling channel RK 2 . The compliance sheet  62  is formed of an elastic material and absorbs a change in the pressure of the ink in the discharge channel RA 2  and the coupling channel RK 2 . 
     As described above, the liquid ejecting head  1  according to the present embodiment causes the ink to circulate from the supply channel RA 1  to the discharge channel RA 2  via the circulation channel RJ. Therefore, in the present embodiment, even when a period during which the ink in the pressure chamber CBq is not ejected from the nozzle N exists, it is possible to prevent the ink from continuously remaining in the pressure chamber CBq, the nozzle channel RN, or the like. Thus, in the present embodiment, even when a period during which the ink in the pressure chamber CBq is not ejected from the nozzle N exists, it is possible to avoid an increase in the viscosity of the ink in the pressure chamber CBq, thus making it possible to prevent an occurrence of an ejection abnormality that makes it difficult for the ink to be ejected from the nozzle N due to an increase in the viscosity of the ink. 
     Moreover, the liquid ejecting head  1  according to the present embodiment is able to eject, from the nozzle N, the ink filled in the pressure chamber CB 1  and the ink filled in the pressure chamber CB 2 . Therefore, the liquid ejecting head  1  according to the present embodiment is able to increase the amount of the ink ejected from the nozzle N, for example, compared with an aspect in which ink filled in only one pressure chamber CBq is ejected from the nozzle N. 
     3. Shape of Circulation Channel 
     The shape of the circulation channel RJ will be described below with reference to  FIGS.  5  and  6   . 
       FIG.  5    is a sectional view of the circulation channel RJ for illustrating the pressure chamber CB 1 , the communication channel RR 1 , the nozzle channel RN, the communication channel RR 2 , and the pressure chamber CB 2 . 
     As illustrated in  FIG.  5   , the nozzle channel RN has a wall surface HNa on the +Z side and a wall surface HNb on the −Z side as viewed in the Y-axis direction. Here, the wall surface HNa is a wall surface in which the nozzle N is formed of the wall surfaces forming the nozzle channel RN and which extends in the X-axis direction as viewed in the Y-axis direction. The wall surface HNb is a wall surface which is opposite to the wall surface HNa of the two wall surfaces forming the nozzle channel RN as viewed in the Y-axis direction and which extends in the X-axis direction as viewed in the Y-axis direction. 
     The communication channel RR 1  has a wall surface HRa 1  on the +X side and a wall surface HRb 1  on the −X side as viewed in the Y-axis direction. Here, the wall surface HRa 1  is a wall surface a distance from which to the nozzle N in the X-axis direction is the longest of the wall surfaces forming the communication channel RR 1  and which extends in the Z-axis direction as viewed in the Y-axis direction. Note that, in the present embodiment, it is assumed that a distance from one object to another object is the shortest distance from the object to the other object. The wall surface HRb 1  is a wall surface which is opposite to the wall surface HRa 1  of the two wall surfaces that form the communication channel RR 1  and that extend in the Z-axis direction as viewed in the Y-axis direction. 
     The communication channel RR 2  has a wall surface HRa 2  on the −X side and a wall surface HRb 2  on the +X side as viewed in the Y-axis direction. Here, the wall surface HRa 2  is a wall surface a distance from which to the nozzle N in the X axis direction is the longest of the wall surfaces forming the communication channel RR 2  and which extends in the Z-axis direction as viewed in the Y-axis direction. The wall surface HRb 2  is a wall surface which is opposite to the wall surface HRa 2  of the two wall surfaces that form the communication channel RR 2  and that extend in the Z-axis direction as viewed in the Y-axis direction. 
     The pressure chamber CB 1  has a wall surface HC 1  as viewed in the Y-axis direction. Here, the wall surface HC 1  is a wall surface on the +Z side of the two wall surfaces that form the pressure chamber CB 1  and that extend in the X-axis direction as viewed in the Y-axis direction. 
     The pressure chamber CB 2  has a wall surface HC 2  as viewed in the Y-axis direction. Here, the wall surface HC 2  is a wall surface on the +Z side of the two wall surfaces that form the pressure chamber CB 2  and that extend in the X-axis direction as viewed in the Y-axis direction. 
     Note that, in the present embodiment, the nozzle N is provided at a substantially central position in the nozzle channel RN. For example, the distance from the nozzle N to the wall surface HRb 1  in the X-axis direction and the distance from the nozzle N to the wall surface HRb 2  in the X-axis direction may be substantially identical. Here, the term “the substantially central position” includes not only a case of being strictly the center but also a case of being regarded as the center within a tolerance. 
     As illustrated in  FIG.  5   , an inclined surface HD 1  that extends in direction W 1  as viewed in the Y-axis direction is provided between the wall surface HNb and the wall surface HRb 1 . More specifically, the inclined surface HD 1  is provided so as to couple the wall surface HNb and the wall surface HRb 1 . 
     Here, direction W 1  is set between the +X direction and the −Z direction. Note that, in the present embodiment, the inclined surface HD 1  is provided such that angle θ 11  formed between direction W 1  and the +X direction is larger than 30° and smaller than 60° and angle θ 12  formed between direction W 1  and the −Z direction is larger than 30° and smaller than 60°. In other words, in the present embodiment, angle θ 11  formed between the direction normal to the inclined surface HD 1  and the direction normal to the wall surface HNb is larger than 30° and smaller than 60° and angle θ 12  formed between the direction normal to the inclined surface HD 1  and the direction normal to the wall surface HRb 1  is larger than 30° and smaller than 60°. Note that it is sufficient that angle θ 11  be larger than 20° and smaller than 80° and angle θ 12  be larger than 10° and smaller than 70°. Further, angle θ 11  and angle θ 12  may be set to be substantially identical at, for example, 45°. 
     As illustrated in  FIG.  5   , an inclined surface HD 2  that extends in direction W 2  as viewed in the Y-axis direction is provided between the wall surface HNb and the wall surface HRb 2 . More specifically, the inclined surface HD 2  is provided so as to couple the wall surface HNb and the wall surface HRb 2 . 
     Here, direction W 2  is set between the −X direction and the −Z direction. Note that, in the present embodiment, the inclined surface HD 2  is provided such that angle θ 21  formed between direction W 2  and the −X direction is larger than 30° and smaller than 60° and angle θ 22  formed between direction W 2  and the −Z direction is larger than 30° and smaller than 60°. In other words, in the present embodiment, angle θ 21  formed between the direction normal to the inclined surface HD 2  and the direction normal to the wall surface HNb is larger than 30° and smaller than 60° and angle θ 22  formed between the direction normal to the inclined surface HD 2  and the direction normal to the wall surface HRb 2  is larger than 30° and smaller than 60°. Note that it is sufficient that angle θ 21  be larger than 20° and smaller than 80° and angle θ 22  be larger than 10° and smaller than 70°. Further, angle θ 21  and angle θ 22  may be set to be substantially identical at, for example, 45°. Angle θ 21  and angle θ 11  may be set to be substantially identical. Further, angle θ 22  and angle θ 12  may be set to be substantially identical. 
     Note that the wall surface HNa is coupled to the wall surface HRa 1  and the wall surface HRa 2 . In other words, an inclined surface is provided neither between the wall surface HNa and the wall surface HRa 1  nor between the wall surface HNa and the wall surface HRa 2 . 
     Moreover, the wall surface HRa 1  is coupled to the wall surface HC 1 , and the wall surface HRa 2  is coupled to the wall surface HC 2 . In other words, an inclined surface is provided neither between the wall surface HRa 1  and the wall surface HC 1  nor between the wall surface HRa 2  and the wall surface HC 2 . 
       FIG.  6    is a view for explaining an example of the flow rate of the ink in the circulation channel RJ when the piezoelectric element PZq is not driven with the driving signal Com and no ink is ejected from the nozzle N and when the ink flows from the communication channel RR 1  to the communication channel RR 2  via the nozzle channel RN. Note that, in  FIG.  6   , an area Ar 1  is an area in which the flow rate of the ink is velocity V 1  or more, an area Ar 2  is an area in which the flow rate of the ink is velocity V 2  or more and less than the velocity V 1 , an area Ar 3  is an area in which the flow rate of the ink is velocity V 3  or more and less than the velocity V 2 , and an area Ar 4  is an area in which the flow rate of the ink is less than the velocity V 3 . Here, it is assumed that the velocities V 1  to V 3  satisfy 0≤V 3 &lt;V 2 &lt;V 1 . 
     As illustrated in  FIG.  6   , in the present embodiment, the flow rate of the ink in the vicinity of the center of the circulation channel RJ as viewed in the Y-axis direction is higher than the flow rate of the ink in the vicinity of the wall surface of the circulation channel RJ. 
     Specifically, in the present embodiment, the area Ar 1  is in the vicinity of the center of the circulation channel RJ, the area Ar 3  is in the vicinity of the wall surface of the circulation channel RJ, and the area Ar 2  is between the area Ar 1  and the area Ar 3 . In the present embodiment, the area Ar 4  is in the vicinity of a portion in which the wall surface HNa and the wall surface HRa 1  are coupled and in the vicinity of a portion in which the wall surface HNa and the wall surface HRa 2  are coupled. 
     4. Reference Example 
     For clarifying the effect of the present embodiment, a liquid ejecting head  1 Z according to a reference example will be described below with reference to  FIGS.  7  and  8   . 
       FIG.  7    is a sectional view of a circulation channel, which is provided in the liquid ejecting head  1 Z according to the reference example, as viewed in the Y-axis direction. 
     As illustrated in  FIG.  7   , the liquid ejecting head  1 Z is similar in configuration to the liquid ejecting head  1  according to the embodiment except that the wall surface HNb and the wall surface HRb 1  are coupled and the inclined surface HD 1  is not provided between the wall surface HNb and the wall surface HRb 1  and except that the wall surface HNb and the wall surface HRb 2  are coupled and the inclined surface HD 2  is not provided between the wall surface HNb and the wall surface HRb 2 . That is, the liquid ejecting head  1 Z according to the reference example is similar in configuration to the liquid ejecting head  1  according to the embodiment except that an edge Ed 1  is formed in a portion in which the wall surface HNb and the wall surface HRb 1  are coupled and except that an edge Ed 2  is formed in a portion in which the wall surface HNb and the wall surface HRb 2  are coupled. 
       FIG.  8    is a view for explaining an example of the flow rate of the ink in the circulation channel when the piezoelectric element PZq of the liquid ejecting head  1 Z according to the reference example is not driven with the driving signal Com and no ink is ejected from the nozzle N and when the ink flows from the communication channel RR 1  to the communication channel RR 2  via the nozzle channel RN. 
     As illustrated in  FIG.  8   , in the liquid ejecting head  1 Z according to the reference example, the ink is prevented from flowing in the vicinity of the edge Ed 1  and in the vicinity of the edge Ed 2 . Therefore, in the liquid ejecting head  1 Z according to the reference example, the flow rate of the ink is reduced in the vicinity of the edge Ed 1  and in the vicinity of the edge Ed 2  compared with the flow rate in the liquid ejecting head  1  according to the embodiment. Thus, in the liquid ejecting head  1 Z according to the reference example, the area Ar 4  is in the vicinity of the edge Ed 1  and in the vicinity of the edge Ed 2 . More specifically, in the liquid ejecting head  1 Z according to the reference example, the area Ar 4  is not only in the vicinity of the portion in which the wall surface HNa and the wall surface HRa 1  are coupled and in the vicinity of the portion in which the wall surface HNa and the wall surface HRa 2  are coupled but also in the vicinity of the wall surface HRb 1 , in the vicinity of the wall surface HNb, and in the vicinity of the wall surface HRb 2 . 
     Thus, in the liquid ejecting head  1 Z according to the reference example, air bubbles readily remain in the vicinity of the wall surface HRb 1 , in the vicinity of the wall surface HNb, and in the vicinity of the wall surface HRb 2  compared with the liquid ejecting head  1  according to the embodiment. In a case in which air bubbles remain in the circulation channel such as the nozzle channel RN, even when the piezoelectric element PZq is driven with the driving signal Com, for example, due to air bubbles absorbing the pressure applied from the piezoelectric element PZq for pushing out the ink, a so-called ejection abnormality that makes it difficult for the ink to be ejected from the nozzle N occurs. When an ejection abnormality occurs, the quality of an image formed on the medium PP is deteriorated. In particular, the air bubbles remaining in the circulation channel RJ between the piezoelectric element PZq and the nozzle N make it difficult for the ink to be ejected from the nozzle N upon driving of the piezoelectric element PZq. That is, when air bubbles remain on the +X side of the nozzle N in the vicinity of the wall surface HNb or remain in the vicinity of the wall surface HRb 1 , an ejection abnormality is more likely to occur during ejection of the ink upon driving of the piezoelectric element PZ 1 . Moreover, when air bubbles remain on the −X side of the nozzle N in the vicinity of the wall surface HNb or remain in the vicinity of the wall surface HRb 2 , an ejection abnormality is more likely to occur during ejection of the ink upon driving of the piezoelectric element PZ 2 . 
     On the other hand, in the liquid ejecting head  1  according to the present embodiment, the inclined surface HD 1  is provided between the wall surface HNb and the wall surface HRb 1 , and the inclined surface HD 2  is provided between the wall surface HNb and the wall surface HRb 2 . Therefore, the liquid ejecting head  1  according to the present embodiment is able to suppress a reduction in the flow rate of the ink in the vicinity of the wall surface HRb 1 , in the vicinity of the wall surface HNb, and in the vicinity of the wall surface HRb 2 , compared with the liquid ejecting head  1 Z according to the reference example. Thus, the liquid ejecting head  1  according to the present embodiment is able to reduce the possibility of air bubbles remaining in the circulation channel RJ such as the nozzle channel RN and the possibility of an occurrence of an ejection abnormality caused by the air bubbles, compared with the liquid ejecting head  1 Z according to the reference example. As a result, the liquid ejecting head  1  according to the present embodiment enables formation of an image having higher quality on the medium PP as compared with the liquid ejecting head  1 Z according to the reference example. 
     5. Conclusion of Embodiment 
     As described above, the liquid ejecting head  1  according to the present embodiment includes: the pressure chamber CB 1  that extends in the +X direction and applies pressure to the ink; the pressure chamber CB 2  that extends in the +X direction and applies pressure to the ink; the nozzle channel RN that extends in the +X direction and communicates with the nozzle N for ejecting the ink; the communication channel RR 1  that extends in the −Z direction crossing the +X direction and causes the pressure chamber CB 1  and the nozzle channel RN to communicate with each other; and the communication channel RR 2  that extends in the −Z direction and causes the pressure chamber CB 2  and the nozzle channel RN to communicate with each other, in which wall surfaces of the nozzle channel RN include the wall surface HNa which extends in the +X direction and in which the nozzle N is provided and the wall surface HNb which extends in the +X direction and is opposite to the wall surface HNa, wall surfaces of the communication channel RR 1  include the wall surface HRa 1  which extends in the −Z direction and a distance from which to the nozzle N in the +X direction is the longest and the wall surface HRb 1  which extends in the −Z direction and is opposite to the wall surface HRa 1 , and the inclined surface HD 1  which extends in direction W 1  set between the +X direction and the −Z direction is provided between the wall surface HNb and the wall surface HRb 1 . 
     That is, in the liquid ejecting head  1  according to the present embodiment, since the inclined surface HD 1  is provided between the wall surface HNb and the wall surface HRb 1 , the ink flows more smoothly from the communication channel RR 1  to the nozzle channel RN and from the nozzle channel RN to the communication channel RR 1  compared with an aspect in which the inclined surface HD 1  is not provided between the wall surface HNb and the wall surface HRb 1 . Therefore, the liquid ejecting head  1  according to the present embodiment is able to reduce the possibility of air bubbles remaining in the communication channel RR 1  or the nozzle channel RN compared with an aspect in which the inclined surface HD 1  is not provided between the wall surface HNb and the wall surface HRb 1 . Thereby, the liquid ejecting head  1  according to the present embodiment is able to reduce the possibility of an occurrence of an ejection abnormality caused by the air bubbles compared with the aspect in which the inclined surface HD 1  is not provided between the wall surface HNb and the wall surface HRb 1 . 
     Moreover, in the liquid ejecting head  1  according to the present embodiment, since the pressure chamber CB 1  and the pressure chamber CB 2  communicate with each other via the communication channel RR 1 , the nozzle channel RN, and the communication channel RR 2 , a flow of ink is able to be produced between the pressure chamber CB 1  and the pressure chamber CB 2 . Therefore, the liquid ejecting head  1  according to the present embodiment is able to reduce the possibility of air bubbles remaining in the nozzle channel RN or the like compared with an aspect in which the pressure chamber CB 1  and the pressure chamber CB 2  do not communicate with each other. Thereby, the liquid ejecting head  1  according to the present embodiment is able to reduce the possibility of an occurrence of an ejection abnormality caused by the air bubbles compared with the aspect in which the pressure chamber CB 1  and the pressure chamber CB 2  do not communicate with each other. 
     Note that, in the present embodiment, the pressure chamber CB 1  is an example of “a first pressure chamber”, the pressure chamber CB 2  is an example of “a second pressure chamber”, the communication channel RR 1  is an example of “a first communication channel”, the communication channel RR 2  is an example of “a second communication channel”, the wall surface HNa is an example of “a first wall surface”, the wall surface HNb is an example of “a second wall surface”, the wall surface HRa 1  is an example of “a third wall surface”, the wall surface HRb 1  is an example of “a fourth wall surface”, the inclined surface HD 1  is an example of “a fifth wall surface”, ink is an example of “a liquid”, the +X direction is an example of “a first direction”, the −Z direction is an example of “a second direction”, and direction W 1  is an example of “a third direction”. 
     Moreover, the liquid ejecting head  1  according to the present embodiment includes: the pressure chamber CB 2  that extends in the −X direction and applies pressure to the ink; the pressure chamber CB 1  that extends in the −X direction and applies pressure to the ink; the nozzle channel RN that extends in the −X direction and communicates with the nozzle N for ejecting the ink; the communication channel RR 2  that extends in the −Z direction and causes the pressure chamber CB 2  and the nozzle channel RN to communicate with each other; and the communication channel RR 1  that extends in the −Z direction and causes the pressure chamber CB 1  and the nozzle channel RN to communicate with each other, in which wall surfaces of the nozzle channel RN include the wall surface HNa which extends in the −X direction and in which the nozzle N is provided and the wall surface HNb which extends in the −X direction and is opposite to the wall surface HNa, wall surfaces of the communication channel RR 2  include the wall surface HRa 2  which extends in the −Z direction and a distance from which to the nozzle N in the −X direction is the longest and the wall surface HRb 2  which extends in the −Z direction and is opposite to the wall surface HRa 2 , and the inclined surface HD 2  which extends in direction W 2  set between the −X direction and the −Z direction is provided between the wall surface HNb and the wall surface HRb 2 . 
     Thus, the liquid ejecting head  1  according to the present embodiment is able to reduce the possibility of air bubbles remaining in the communication channel RR 2  or the nozzle channel RN compared with an aspect in which the inclined surface HD 2  is not provided between the wall surface HNb and the wall surface HRb 2 . Thereby, the liquid ejecting head  1  according to the present embodiment is able to reduce the possibility of an occurrence of an ejection abnormality caused by the air bubbles compared with the aspect in which the inclined surface HD 2  is not provided between the wall surface HNb and the wall surface HRb 2 . 
     Moreover, the liquid ejecting head  1  according to the present embodiment is able to reduce the possibility of air bubbles remaining in the nozzle channel RN or the like compared with the aspect in which the pressure chamber CB 1  and the pressure chamber CB 2  do not communicate with each other. Thereby, the liquid ejecting head  1  according to the present embodiment is able to reduce the possibility of an occurrence of an ejection abnormality caused by the air bubbles compared with the aspect in which the pressure chamber CB 1  and the pressure chamber CB 2  do not communicate with each other. 
     In particular, the pressure chamber CB 2  is positioned on the downstream of the nozzle N in the direction in which the ink flows in the circulation channel RJ. Since air bubbles that have entered from the nozzle N flow partially together with the flow of the ink, the air bubbles tend to move to the downstream of the nozzle N rather than to the upstream of the nozzle N. That is, air bubbles remain on the −X side of the wall surface HNb with respect to the nozzle N and on the wall surface HRb 2  more readily than on the +X side of the wall surface HNb with respect to the nozzle N and on the wall surface HRb 1 . Here, when the piezoelectric element PZ 2  is not provided on the downstream of the nozzle N, a remarkable ejection abnormality is not caused by the air bubbles remaining on the downstream of the nozzle N. However, when the piezoelectric element PZ 2  is provided on the downstream of the nozzle N as in the present embodiment, air bubbles readily remain on the downstream of the nozzle N in the circulation channel RJ, and therefore, an ejection abnormality may remarkably occur during ejection of the ink upon driving of the piezoelectric element PZ 2 . Against this, according to the present embodiment, since the inclined surface HD 2  is provided on the downstream of the nozzle N, even when the piezoelectric element PZ 2  is provided on the downstream of the nozzle N, it is possible to suppress an occurrence of an ejection abnormality. 
     Note that, in the present embodiment, the pressure chamber CB 2  is another example of “the first pressure chamber”, the pressure chamber CB 1  is another example of “the second pressure chamber”, the communication channel RR 2  is another example of “the first communication channel”, the communication channel RR 1  is another example of “the second communication channel”, the wall surface HRa 2  is another example of “the third wall surface”, the wall surface HRb 2  is another example of “the fourth wall surface”, the inclined surface HD 2  is another example of “the fifth wall surface”, the −X direction is another example of “the first direction”, and direction W 2  is another example of “the third direction”. 
     Moreover, in the liquid ejecting head  1  according to the present embodiment, angle θ 11  formed between the direction normal to the wall surface HNb and the direction normal to the inclined surface HD 1  may be larger than 20° and smaller than 80°. 
     Therefore, the liquid ejecting head  1  according to the present embodiment is able to reduce the possibility of air bubbles remaining in the communication channel RR 1  or the nozzle channel RN compared with an aspect in which the inclined surface HD 1  is not provided between the wall surface HNb and the wall surface HRb 1  and an angle formed between the direction normal to the wall surface HNb and the direction normal to the wall surface HRb 1  is, for example, 90°. As a result, the liquid ejecting head  1  according to the present embodiment is able to reduce the possibility of an occurrence of an ejection abnormality caused by the air bubbles compared with the aspect in which the inclined surface HD 1  is not provided between the wall surface HNb and the wall surface HRb 1 . 
     Moreover, in the liquid ejecting head  1  according to the present embodiment, angle θ 12  formed between the direction normal to the wall surface HRb 1  and the direction normal to the inclined surface HD 1  may be larger than 10° and smaller than 70°. 
     Therefore, according to the present embodiment, it is possible to reduce the possibility of air bubbles remaining in the communication channel RR 1  or the nozzle channel RN compared with an aspect in which the inclined surface HD 1  is not provided between the wall surface HNb and the wall surface HRb 1  and the angle formed between the direction normal to the wall surface HNb and the direction normal to the wall surface HRb 1  is, for example, 90°. As a result, the liquid ejecting head  1  according to the present embodiment is able to reduce the possibility of an occurrence of an ejection abnormality caused by the air bubbles compared with the aspect in which the inclined surface HD 1  is not provided between the wall surface HNb and the wall surface HRb 1 . 
     Moreover, in the liquid ejecting head  1  according to the present embodiment, the wall surface HNa is coupled to the wall surface HRa 1 . 
     Therefore, according to the present embodiment, it is possible to easily manufacture the liquid ejecting head  1  compared with an aspect in which another component is provided between the wall surface HNa and the wall surface HRa 1 . 
     Moreover, in the liquid ejecting head  1  according to the present embodiment, a wall surface of the pressure chamber CB 1  may include the wall surface HC 1  that extends in the +X direction, and the wall surface HRa 1  may be coupled to the wall surface HC 1 . Therefore, according to the present embodiment, it is possible to easily manufacture the liquid ejecting head  1  compared with an aspect in which another component is provided between the wall surface HRa 1  and the wall surface HC 1 . 
     Note that, in the present embodiment, the wall surface HC 1  is an example of “a sixth wall surface”. 
     Moreover, in the liquid ejecting head  1  according to the present embodiment, wall surfaces of the communication channel RR 2  may include the wall surface HRa 2  which extends in the −Z direction and a distance from which to the nozzle N in the +X direction is the longest and the wall surface HRb 2  which extends in the −Z direction and is opposite to the wall surface HRa 2 , and the inclined surface HD 2  which extends in direction W 2  set between the −X direction and the −Z direction may be provided between the wall surface HNb and the wall surface HRb 2 . Therefore, according to the present embodiment, it is possible to reduce the possibility of air bubbles remaining in the communication channel RR 2  or the nozzle channel RN compared with the aspect in which the inclined surface HD 2  is not provided between the wall surface HNb and the wall surface HRb 2 . As a result, the liquid ejecting head  1  according to the present embodiment is able to reduce the possibility of an occurrence of an ejection abnormality caused by the air bubbles compared with the aspect in which the inclined surface HD 2  is not provided between the wall surface HNb and the wall surface HRb 2 . 
     Note that, in the present embodiment, the wall surface HRa 2  is an example of “a seventh wall surface”, the wall surface HRb 2  is an example of “an eighth wall surface”, the inclined surface HD 2  is an example of “a ninth wall surface”, and direction W 2  is an example of “a fourth direction”. 
     Moreover, in the liquid ejecting head  1  according to the present embodiment, angle θ 12  formed between direction W 1  and the −Z direction may be substantially identical to angle θ 22  formed between direction W 2  and the −Z direction. Therefore, according to the present embodiment, the shape of an ink channel that extends from the pressure chamber CB 1  to the nozzle N via the communication channel RR 1  and the nozzle channel RN is able to be substantially identical to the shape of an ink channel that extends from the pressure chamber CB 2  to the nozzle N via the communication channel RR 2  and the nozzle channel RN. Thereby, according to the present embodiment, it is possible to simplify control for ejecting the ink filled in the pressure chamber CB 1  from the nozzle N and control for ejecting the ink filled in the pressure chamber CB 2  from the nozzle N, for example, compared with an aspect in which angle θ 12  differs from angle θ 22 . 
     Moreover, the liquid ejecting head  1  according to the present embodiment may include the supply channel RA 1  which communicates with the pressure chamber CB 1  and along which the ink is supplied to the pressure chamber CB 1  and the discharge channel RA 2  which communicates with the pressure chamber CB 2  and along which the ink is discharged from the pressure chamber CB 2 . 
     Therefore, according to the present embodiment, a flow of the ink is able to be produced between the pressure chamber CB 1  and the pressure chamber CB 2 . Thus, the liquid ejecting head  1  according to the present embodiment is able to reduce the possibility of air bubbles remaining in the nozzle channel RN or the like compared with an aspect in which no flow of ink is produced between the pressure chamber CB 1  and the pressure chamber CB 2 . As a result, the liquid ejecting head  1  according to the present embodiment is able to reduce the possibility of an occurrence of an ejection abnormality caused by the air bubbles compared with the aspect in which no flow of ink is produced between the pressure chamber CB 1  and the pressure chamber CB 2 . 
     Moreover, the liquid ejecting head  1  according to the present embodiment may include the pressure chamber substrate  3  in which the pressure chamber CB 1  and the pressure chamber CB 2  are provided, the communication plate  2  in which the nozzle channel RN, the communication channel RR 1 , and the communication channel RR 2  are provided, and the nozzle substrate  60  in which the nozzle N is provided. 
     Therefore, according to the present embodiment, it is possible to manufacture the pressure chamber CB 1 , the pressure chamber CB 2 , the nozzle channel RN, the communication channel RR 1 , the communication channel RR 2 , and the nozzle N by using a semiconductor manufacturing technique. Further, according to the present embodiment, it is possible to achieve miniaturization and densification of the pressure chamber CB 1 , the pressure chamber CB 2 , the nozzle channel RN, the communication channel RR 1 , the communication channel RR 2 , and the nozzle N. 
     Moreover, in the liquid ejecting head  1  according to the present embodiment, the nozzle N may communicate with the nozzle channel RN at a substantially central position of the nozzle channel RN. 
     Therefore, according to the present embodiment, the shape of the ink channel that extends from the pressure chamber CB 1  to the nozzle N via the communication channel RR 1  and the nozzle channel RN is able to be substantially identical to the shape of the ink channel that extends from the pressure chamber CB 2  to the nozzle N via the communication channel RR 2  and the nozzle channel RN. Thereby, according to the present embodiment, it is possible to simplify control for ejecting the ink filled in the pressure chamber CB 1  from the nozzle N and control for ejecting the ink filled in the pressure chamber CB 2  from the nozzle N, for example, compared with an aspect in which the nozzle N communicates with the nozzle channel RN at a position different from the center of the nozzle channel RN. 
     Moreover, the liquid ejecting head  1  according to the present embodiment may include the piezoelectric element PZ 1  that applies pressure to the ink in the pressure chamber CB 1  in response to supply of the driving signal Com 1  and the piezoelectric element PZ 2  that applies pressure to the ink in the pressure chamber CB 2  in response to supply of the driving signal Com 2 . Therefore, according to the present embodiment, it is possible to increase the amount of the ink ejected from the nozzle N compared with an aspect in which only the piezoelectric element PZq that applies pressure to the ink in one pressure chamber CBq is provided. 
     Note that, in the present embodiment, the piezoelectric element PZ 1  is an example of “a first element”, the piezoelectric element PZ 2  is an example of “a second element”, the driving signal Com 1  is an example of “a first driving signal”, and the driving signal Com 2  is an example of “a second driving signal”. 
     Moreover, in the liquid ejecting head  1  according to the present embodiment, the waveform of the driving signal Com 1  and the waveform of the driving signal Com 2  may be substantially identical. 
     Therefore, according to the present embodiment, it is possible to simplify control for ejecting the ink filled in the pressure chamber CB 1  from the nozzle N and control for ejecting the ink filled in the pressure chamber CB 2  from the nozzle N compared with an aspect in which the waveform of the driving signal Com  1  differs from the waveform of the driving signal Com 2 . 
     B. Modification 
     Each aspect exemplified above can be variously modified. Specific modified aspects will be exemplified below. Any two or more aspects selected from the following examples can be appropriately combined as long as the aspects do not contradict each other. 
     Modification 1 
     Although an aspect in which the wall surface HNa and the wall surface HRa 1  are coupled and the wall surface HNa and the wall surface HRa 2  are coupled is exemplified in the embodiment described above, the disclosure is not limited to the aspect. For example, another wall surface may be provided between the wall surface HNa and the wall surface HRa 1  or another wall surface may be provided between the wall surface HNa and the wall surface HRa 2 . 
       FIG.  9    is a sectional view of a liquid ejecting head  1 A according to the present modification. The liquid ejecting head  1 A according to the present modification is similar in configuration to the liquid ejecting head  1  except that a communication plate  2 A is provided instead of the communication plate  2 . 
     As illustrated in  FIG.  9   , the communication plate  2 A differs from the communication plate  2  according to the embodiment in terms of including a cavity RX 1  and a cavity RX 2 . Here, the cavity RX 1  communicates with the nozzle channel RN and is provided on the +X side of the nozzle channel RN. The cavity RX 2  communicates with the nozzle channel RN and is provided on the −X side of the nozzle channel RN. Note that an inclined surface HX 1  that extends in direction W 2  as viewed in the Y-axis direction may be provided between a wall surface of the cavity RX 1  and the wall surface HRa 1 . An inclined surface HX 2  that extends in direction W 1  as viewed in the Y-axis direction may be provided between a wall surface of the cavity RX 2  and the wall surface HRa 2 . 
     Also in the present modification, since the inclined surface HD 1  is provided between the wall surface HNb and the wall surface HRb 1 , it is possible to reduce the possibility of air bubbles remaining in the communication channel RR 1  or the nozzle channel RN compared with the aspect in which the inclined surface HD 1  is not provided between the wall surface HNb and the wall surface HRb 1 . Further, also in the present modification, since the inclined surface HD 2  is provided between the wall surface HNb and the wall surface HRb 2 , it is possible to reduce the possibility of air bubbles remaining in the communication channel RR 2  or the nozzle channel RN compared with the aspect in which the inclined surface HD 2  is not provided between the wall surface HNb and the wall surface HRb 2 . 
     Modification 2 
     Although an aspect in which two piezoelectric elements PZq of the piezoelectric element PZ 1  and the piezoelectric element PZ 2  are provided so as to correspond to each of the nozzles N is exemplified in the embodiment and Modification 1 described above, the disclosure is not limited to the aspect. For example, one piezoelectric element PZ may be provided so as to correspond to each of the nozzles N. 
       FIG.  10    is an exploded perspective view of a liquid ejecting head  1 B according to the present modification. 
     As illustrated in  FIG.  10   , the liquid ejecting head  1 B according to the present modification differs from the liquid ejecting head  1  of the embodiment in terms of including a nozzle substrate  60 B instead of the nozzle substrate  60 , including the communication plate  2 B instead of the communication plate  2 , including a pressure chamber substrate  3 B instead of the pressure chamber substrate  3 , and including a vibrating plate  4 B instead of the vibrating plate  4 . 
     Among these, the nozzle substrate  60 B differs from the nozzle substrate  60  according to the embodiment in terms of including a nozzle row Ln 1  and a nozzle row Ln 2  instead of the nozzle row Ln. Here, the nozzle row Ln 1  is a set of M 1  nozzles N that are provided so as to extend in the Y-axis direction. The nozzle row Ln 2  is a set of M 2  nozzles N that are provided, on the −X side of the nozzle row Ln 1 , so as to extend in the Y axis direction. Here, values of M 1  and M 2  are natural numbers of 1 or more that satisfy M 1 +M 2 =M. Note that, in the present modification, a case where the value of M is a natural number of 2 or more is assumed. Moreover, in the following description, the nozzles N that form the nozzle row Ln 1  are sometimes referred to as nozzles N 1  and the nozzles N that form the nozzle row Ln 2  are sometimes referred to as nozzles N 2 . 
     The communication plate  2 B differs from the communication plate  2  according to the embodiment in terms of including M 1  coupling channels RK 1  corresponding on a one-to-one basis to M 1  nozzles N 1 , M 2  coupling channels RK 2  corresponding on a one-to-one basis to M 2  nozzles N 2 , M 1  communication channels RR 1  corresponding on a one-to-one basis to the M 1  nozzles N 1 , and M 2  communication channels RR 2  corresponding on a one-to-one basis to the M 2  nozzles N 2  instead of the M coupling channels RK 1 , the M coupling channels RK 2 , the M communication channels RR 1 , and the M communication channels RR 2 . Further, similarly to the communication plate  2 , the supply channel RA 1  that extends in the Y-axis direction and the discharge channel RA 2  that is provided, in the −X direction as viewed from the supply channel RA 1 , so as to extend in the Y-axis direction are formed in the communication plate  2 B. 
     Moreover, the pressure chamber substrate  3 B differs from the pressure chamber substrate  3  according to the embodiment in that M 1  pressure chambers CB 1  corresponding on a one-to-one basis to the M 1  nozzles N 1  and M 2  pressure chambers CB 2  corresponding on a one-to-one basis to the M 2  nozzles N 2  are formed instead of the M pressure chambers CB 1  and the M pressure chambers CB 2 . 
     Moreover, the vibrating plate  4 B differs from the vibrating plate  4  according to the embodiment in that M 1  piezoelectric elements PZ 1  corresponding on a one-to-one basis to the M 1  nozzles N 1  and M 2  piezoelectric elements PZ 2  corresponding on a one-to-one basis to the M 2  nozzles N 2  are formed instead of the M piezoelectric elements PZ 1  and the M piezoelectric elements PZ 2 . 
       FIG.  11    is a plan view of the liquid ejecting head  1 B as viewed in the Z-axis direction. 
     In the present modification, the liquid ejecting head  1 B includes M circulation channels RJ corresponding on a one-to-one basis to the M nozzles N provided in the nozzle substrates  60 B. In the following description, circulation channels RJ provided so as to correspond to the nozzles N 1  are sometimes referred to as circulation channels RJ 1 , and circulation channels RJ provided so as to correspond to the nozzles N 2  are sometimes referred to as circulation channels RJ 2 . That is, in the present modification, M 1  circulation channels RJ 1  and M 2  circulation channels RJ 2  cause the supply channel RA 1  and the discharge channel RA 2  to communicate with each other. In the present modification, a circulation channel RJ 1  and a circulation channel RJ 2  are alternately arranged in the Y-axis direction. Moreover, in the present modification, the M 1  circulation channels RJ 1  and the M 2  circulation channels RJ 2  are arranged such that a distance between the circulation channel RJ 1  and the circulation channel RJ 2  that are adjacent to each other in the Y-axis direction is a distance dY. 
     As described above, the circulation channel RJ 1  has the pressure chamber CB 1 , and the circulation channel RJ 2  has the pressure chamber CB 2 . In the present modification, as illustrated in  FIG.  11   , the pressure chamber CB 1  is provided on the +X side of a nozzle N 1 , the pressure chamber CB 2  is provided on the −X side of a nozzle N 2 . As described above, the nozzle row Ln 1  to which the nozzles N 1  belong is provided on the +X side of the nozzle row Ln 2  to which the nozzles N 2  belong. Therefore, in the present modification, the pressure chamber CB 1  is positioned on the +X side of the pressure chamber CB 2 . 
     In the present modification, the circulation channel RJ is provided such that the width of the pressure chamber CBq in the Y-axis direction is width dCY and a width of a portion other than the pressure chamber CBq is width dRY or less. In the present modification, a case where width dRY and width dCY satisfy dRY&lt;dCY is assumed. Further, in the present modification, as an example, a case where the M 1  circulation channels RJ 1  and the M 2  circulation channels RJ 2  are provided such that the distance dY and the width dCY satisfy dCY&gt;dY is assumed. 
     As described above, in the present modification, since the position of the pressure chamber CB 1  in the X-axis direction differs from the position of the pressure chamber CB 2  in the X-axis direction, a pitch at which circulation channels RJ are provided is able to be narrowed compared with an aspect in which the pressure chamber CB 1  and the pressure chamber CB 2  are provided at the same position in the X-axis direction. 
       FIG.  12    is a sectional view of the liquid ejecting head  1 B, which is taken parallel to the XZ plane so as to pass through the circulation channel RJ 1 .  FIG.  13    is a sectional view of the liquid ejecting head  1 B, which is taken parallel to the XZ plane so as to pass through the circulation channel RJ 2 . 
     As illustrated in  FIGS.  12  and  13   , in the present modification, the communication plate  2 B includes a substrate  21  and a substrate  22 . Here, each of the substrate  21  and the substrate  22  is manufactured, for example, in such a manner that a silicon monocrystalline substrate is processed by using a semiconductor manufacturing technique such as etching. Note that any known material and process can be adopted to manufacture each of the substrate  21  and the substrate  22 . 
     As illustrated in  FIG.  12   , in the present modification, the circulation channel RJ 1  includes the coupling channel RK 1  that communicates with the supply channel RA 1  and is formed in the substrate  21  and the substrate  22 , the pressure chamber CB 1  that communicates with the coupling channel RK 1  and is formed in the pressure chamber substrate  3 B, the communication channel RR 1  that communicates with the pressure chamber CB 1  and is formed in the substrate  21  and the substrate  22 , a nozzle channel RN 1  that communicates with the communication channel RR 1  and the nozzle N 1  and is formed in the substrate  21 , a channel R 11  that communicates with the nozzle channel RN 1  and is formed in the substrate  22 , a channel R 12  that communicates with the channel R 11  and is formed in the substrate  21 , a channel R 13  that communicates with the channel R 12  and is formed in the nozzle substrate  60 B, a channel R 14  that communicates with the channel R 13  and is formed in the substrate  21 , and a channel R 15  that causes the channel R 14  and the discharge channel RA 2  to communicate with each other and is formed in the substrate  22 . 
     As illustrated in  FIG.  13   , in the present modification, the circulation channel RJ 2  includes the coupling channel RK 2  that communicates with the discharge channel RA 2  and is formed in the substrate  21  and the substrate  22 , the pressure chamber CB 2  that communicates with the coupling channel RK 2  and is formed in the pressure chamber substrate  3 B, the communication channel RR 2  that communicates with the pressure chamber CB 2  and is formed in the substrate  21  and the substrate  22 , a nozzle channel RN 2  that communicates with the communication channel RR 2  and the nozzle N 2  and is formed in the substrate  21 , a channel R 21  that communicates with the nozzle channel RN 2  and is formed in the substrate  22 , a channel R 22  that communicates with the channel R 21  and is formed in the substrate  21 , a channel R 23  that communicates with the channel R 22  and is formed in the nozzle substrate  60 B, a channel R 24  that communicates with the channel R 23  and is formed in the substrate  21 , and a channel R 25  that causes the channel R 24  and the supply channel RA 1  to communicate with each other and is formed in the substrate  22 . 
       FIG.  14    is a sectional view of the circulation channel RJ 1  for illustrating the pressure chamber CB 1 , the communication channel RR 1 , the nozzle channel RN 1 , and the channel R 11 . 
     As illustrated in  FIG.  14   , the nozzle channel RN 1  includes a wall surface HNa 1 , a wall surface HNb 1 , and a wall surface HNc 1  as viewed in the Y-axis direction. Here, the wall surface HNa 1  is a wall surface in which the nozzle N 1  is formed among the wall surfaces forming the nozzle channel RN 1  and which extends in the X-axis direction as viewed in the Y-axis direction. The wall surface HNb 1  is a wall surface which is opposite to the wall surface HNa 1  as viewed in the Y-axis direction and which extends in the X-axis direction. The wall surface HNc 1  is a wall surface which forms an end of the nozzle channel RN 1  on the −X side and which extends in the Z-axis direction as viewed in the Y-axis direction. 
     The channel R 11  has a wall surface Hila, a wall surface H 11   b , and an inclined surface H 11  as viewed in the Y-axis direction. Here, the wall surface Hila is a wall surface which is coupled to the wall surface HNc 1  and which extends in the X-axis direction as viewed in the Y-axis direction. The wall surface H 11   b  is a wall surface which is opposite to the wall surface Hila as viewed in the Y-axis direction and which extends in the X-axis direction. The inclined surface H 11  is a wall surface which is provided between the wall surface HNb 1  and the wall surface H 11   b  and which extends in direction W 2  as viewed in the Y-axis direction. 
     Note that, in the present modification, the inclined surface HD 1  is provided between the wall surface HNb 1  and the wall surface HRb 1 . In the present modification, the wall surface HRa 1  is coupled to the wall surface HNa 1 . 
       FIG.  15    is a sectional view of the circulation channel RJ 2  for illustrating the pressure chamber CB 2 , the communication channel RR 2 , the nozzle channel RN 2 , and the channel R 21 . 
     As illustrated in  FIG.  15   , the nozzle channel RN 2  includes a wall surface HNa 2 , a wall surface HNb 2 , and a wall surface HNc 2  as viewed in the Y-axis direction. Here, the wall surface HNa 2  is a wall surface in which the nozzle N 2  is formed among the wall surfaces forming the nozzle channel RN 2  and which extends in the X-axis direction as viewed in the Y-axis direction. The wall surface HNb 2  is a wall surface which is opposite to the wall surface HNa 2  as viewed in the Y-axis direction and which extends in the X-axis direction. The wall surface HNc 2  is a wall surface which forms an end of the nozzle channel RN 2  on the +X side and which extends in the Z-axis direction as viewed in the Y-axis direction. 
     The channel R 21  has a wall surface H 21   a , a wall surface H 21   b , and an inclined surface H 21  as viewed in the Y-axis direction. Here, the wall surface H 21   a  is a wall surface which is coupled to the wall surface HNc 2  and which extends in the X-axis direction as viewed in the Y-axis direction. The wall surface H 21   b  is a wall surface which is opposite to the wall surface H 21   a  as viewed in the Y-axis direction and which extends in the X-axis direction. The inclined surface H 21  is a wall surface which is provided between the wall surface HNb 2  and the wall surface H 21   b  and which extends in direction W 1  as viewed in the Y-axis direction. 
     Note that, in the present modification, the inclined surface HD 2  is provided between the wall surface HNb 2  and the wall surface HRb 2 . In the present modification, the wall surface HRa 2  is coupled to the wall surface HNa 2 . 
     Also in the present modification, since the inclined surface HD 1  is provided between the wall surface HNb 1  and the wall surface HRb 1 , it is possible to reduce the possibility of air bubbles remaining in the communication channel RR 1  or the nozzle channel RN 1  compared with an aspect in which the inclined surface HD 1  is not provided between the wall surface HNb 1  and the wall surface HRb 1 . Further, also in the present modification, since the inclined surface HD 2  is provided between the wall surface HNb 2  and the wall surface HRb 2 , it is possible to reduce the possibility of air bubbles remaining in the communication channel RR 2  or the nozzle channel RN 2  compared with an aspect in which the inclined surface HD 2  is not provided between the wall surface HNb 2  and the wall surface HRb 2 . 
     Modification 3 
     Although the liquid ejecting apparatus  100  of a serial type in which the endless belt  922  on which the liquid ejecting head  1 , the liquid ejecting head  1 A, or the liquid ejecting head  1 B is mounted is reciprocated in the Y-axis direction is exemplified in the embodiment and Modifications 1 and 2 described above, the disclosure is not limited to such an aspect. The liquid ejecting apparatus may be a liquid ejecting apparatus of a line type in which a plurality of nozzles N are distributed over the entire width of the medium PP. 
       FIG.  16    illustrates an example of a configuration of a liquid ejecting apparatus  100 C according to the present modification. The liquid ejecting apparatus  100 C differs from the liquid ejecting apparatus  100  according to the embodiment in terms of including a control device  90 C instead of the control device  90 , including a storage case  921 C instead of the storage case  921 , and not including the endless belt  922 . The control device  90 C differs from the control device  90  in terms of outputting no signal for controlling the endless belt  922 . The storage case  921 C is provided such that the plurality of liquid ejecting heads  1  having a longitudinal direction in the Y-axis direction are distributed over the entire width of the medium PP. Note that liquid ejecting heads  1 A or liquid ejecting heads  1 B may be mounted on the storage case  921 C instead of the liquid ejecting heads  1 . 
     Modification 4 
     Although the piezoelectric element PZ that converts electrical energy into kinetic energy is exemplified as the energy conversion element that applies pressure to the inside of the pressure chamber CB in the embodiment and Modifications 1 to 3 described above, the disclosure is not limited to such an aspect. As the energy conversion element that applies pressure to the inside of the pressure chamber CB, for example, a heating element that converts electrical energy into thermal energy, performs heating to generate air bubbles in the pressure chamber CB, and changes the pressure in the pressure chamber CB. The heating element may be, for example, an element in which a heating material generates heat in accordance with supply of the driving signal Com. 
     Modification 5 
     The liquid ejecting apparatus exemplified in the embodiment and Modifications 1 to 4 described above can be adopted for various apparatuses such as a facsimile apparatus and a copying machine in addition to equipment dedicated to printing. However, 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.