Patent Publication Number: US-9889657-B2

Title: Liquid ejecting head and liquid ejecting apparatus

Description:
BACKGROUND 
     1. Technical Field 
     The present invention relates to a technique for ejecting liquid such as ink. 
     2. Related Art 
     In the related art, a liquid ejecting head which ejects liquid such as ink which is filled in a pressure chamber from nozzles has been proposed. For example, in JP-A-2013-129191, a structure in which liquid is supplied to a pressure chamber from a common liquid chamber in which a liquid chamber hollow portion which is formed on the communicating substrate, and a liquid chamber forming hollow portion of a unit case which is fixed to the communicating substrate are caused to communicate with each other is disclosed. 
     In order to achieve miniaturization of a liquid ejecting head, it is necessary to reduce the wall thickness of the unit case. However, there is a problem in that it is difficult to secure mechanical strength of the liquid ejecting head due to the reduction of the wall thickness. 
     SUMMARY 
     An advantage of some aspects of the invention is to improve mechanical strength of constituents forming a space storing liquid 
     An advantage of some aspects of the invention is to provide a liquid ejecting head which includes a head main body in which a plurality of nozzles ejecting liquid are arranged along a first direction; a housing fixed to the head main body; a liquid storage chamber that includes a space formed in the housing, and stores the liquid supplied to the nozzles; an introducing port of the liquid communicating with the liquid storage chamber; and a plurality of beam-shaped units that are stretched over an inner wall face of the space in the housing, in which the plurality of beam-shaped units are provided with intervals such that a plurality of flow paths are arranged in the first direction from the introducing port, and in which among the plurality of flow paths, a first flow path far away from the introducing port in the first direction has a flow path width in the first direction smaller than that of a second flow path close to the introducing port. In the above described configuration, since the beam-shaped unit is provided in the housing, it is possible to improve mechanical strength of the housing compared to a configuration in which the beam-shaped unit is not provided. In addition, since among the plurality of flow paths, the first flow path far away from the introducing port has the flow path width in the first direction smaller than that of the second flow path, the flow rate in the first flow path is increased, and the gap between the inner wall face of the first flow path and the bubble is reduced. Accordingly, it is possible to easily discharge the bubble through the first flow path. Meanwhile, since the second flow path close to the introducing port has the flow path width in the first direction larger than that of the first flow path, it is possible to secure the flow rate of the liquid. 
     In a preferable aspect of the invention, the liquid storage chamber includes a first space on an upstream side of the plurality of beam-shaped units, and a second space on a downstream side of the plurality of beam-shaped units, and the flow path width of the first flow path in a second direction intersecting the first direction is smaller than a height of the first space in a third direction orthogonal to both the first direction and the second direction. In the above described aspect, since the flow path area of the first flow path is reduced compared to the configuration in which the flow path width of the first flow path in the second direction is larger than the height of the first space, it is possible to increase the flow rate of the liquid passing through the first flow path. Accordingly, it is possible to promote the discharge of the bubble through the first flow path. Since the height greater than the first flow path width is secured in the first space, there is an advantage in that the flow rate of the liquid flowing in a space on the upstream side of the beam-shaped unit is easily secured. 
     In a preferable aspect of the invention, the flow path width of the first flow path in the first direction is smaller than the height of the first space in the third direction. In the above described aspect, since both the flow path width in the first direction and the flow path width in the second direction of the first flow path far away from the introducing port are reduced, the flow path area of the first flow path is reduced. Accordingly, the effect in which it is possible to promote the discharge of the bubble by the suppression of the gap between the bubble and the inner wall face of the first flow path, and by the increase of the flow rate of the liquid is particularly remarkable. 
     In a preferable aspect of the invention, the liquid storage chamber includes, from the introducing port, a portion parallel to a plane including the first direction and the second direction, and a portion orthogonal to the plane, and the beam-shaped unit is formed in the orthogonal portion in the liquid storage chamber. In the above described aspect, when the liquid flows from the parallel portion to the orthogonal portion in the liquid storage chamber, since the liquid passes through the flow path formed by the beam-shaped unit, at this time, it is possible to easily discharge the bubble in the first flow path far away from the introducing port while the flow rate of the liquid is secured. 
     In a preferable aspect of the invention, there is provided a liquid ejecting apparatus that includes the liquid ejecting head according to each of the above exemplified aspects. A preferable example of the liquid ejecting apparatus is a printing apparatus which ejects ink; however, a use of the liquid ejecting apparatus according to the invention is not limited to printing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a configuration diagram of a printing apparatus according to an embodiment of the invention. 
         FIG. 2  is an exploded perspective view of a liquid ejecting head. 
         FIG. 3  is a sectional view (sectional view which is taken along line III-III in  FIG. 2 ) of the liquid ejecting head. 
         FIG. 4  is a plan view of a housing. 
         FIG. 5  is a perspective view enlargedly illustrating a beam-shaped unit. 
         FIG. 6  is an explanatory diagram illustrating operations of the liquid ejecting head according to the embodiment. 
         FIG. 7  is an explanatory diagram illustrating operations of a liquid ejecting head according to a comparative example. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       FIG. 1  is a partial configuration diagram of an ink jet printing apparatus  10  according to an embodiment of the invention. The printing apparatus  10  according to the embodiment is a preferable example of a liquid ejecting apparatus which ejects ink as an example of liquid onto a medium (ejecting target)  12  such as a printing sheet, and as exemplified in  FIG. 1 , the printing apparatus includes a control device  22 , a transport mechanism  24 , a carriage  26 , and a plurality of liquid ejecting heads  100 . A liquid container (cartridge)  14  which stores ink is mounted on the printing apparatus  10 . 
     The control device  22  integrally controls each element of the printing apparatus  10 . The transport mechanism  24  transports the medium  12  in the Y direction (an example of a first direction) under control of the control device  22 . Each liquid ejecting head  100  ejects ink onto the medium  12  from a plurality of nozzles under control of the control device  22 . The plurality of liquid ejecting heads  100  are mounted on the carriage  26 . The control device  22  causes the carriage  26  to reciprocate in the X direction (an example of a second direction) which intersects the Y direction. A desired image is formed on the surface of the medium  12  when each liquid ejecting head  100  ejects ink onto the medium  12  in parallel with transporting of the medium  12  using the transport mechanism  24  and repeated reciprocating of the carriage  26 . In addition, hereinafter, a direction which is perpendicular to an X-Y plane (for example, plane parallel to surface of medium  12 ) will be denoted by a Z direction. An ink ejecting direction (typically, vertical direction) using each liquid ejecting head  100  corresponds to the Z direction (an example of a third direction). 
       FIG. 2  is an exploded perspective view of one arbitrary liquid ejecting head  100 , and  FIG. 3  is a sectional view which is taken along line III-III in  FIG. 2 . As exemplified in  FIG. 2 , the liquid ejecting head  100  of the embodiment includes a head main body  30  in which nozzles N ejecting ink are formed, and a housing  40  fixed to the head main body  30 . 
     As illustrated in  FIG. 2 , the head main body  30  includes a nozzle plate  52  on which the plurality of nozzles N are formed. The plurality of nozzles N are divided into a first column L 1  and a second column L 2  arranged along the Y direction. The first column L 1  and the second column L 2  are separated from each other in the X direction, and positions of the nozzles N in the Y direction are different from each other between the first column L 1  and the second column L 2 . That is, the plurality of nozzles N are subjected to a staggered arrangement. As is understood from  FIG. 2 , the liquid ejecting head  100  according to the embodiment has a structure in which elements related to the plurality of nozzles N of the first column L 1 , and elements related to the plurality of nozzles N of the second column L 2  are arranged approximately in line symmetry. Therefore, in the following descriptions, the elements related to each nozzle N of the first column L 1  will be paid attention to, for convenience, and descriptions of the elements related to each nozzle N of the second column L 2  will be appropriately omitted. 
     As exemplified in  FIGS. 2 and 3 , the liquid ejecting head  100  according to the first embodiment includes a flow path substrate  32 . The flow path substrate  32  is a plate-shaped member which includes a first face F 1  and a second face F 2 . The first face F 1  is a surface on the negative side in the Z direction, and the second face F 2  is a surface on a side opposite to the first face F 1  (positive side in Z direction). A pressure chamber substrate  34 , a vibrating unit  36 , a plurality of piezoelectric elements  37 , a protecting member  38 , and a housing  40  are provided on the first face F 1  of the flow path substrate  32 , and the nozzle plate  52 , and a compliance unit  54  are provided on the second face F 2 . Each of the elements of the liquid ejecting head  100  is schematically a plate-shaped member which is long in the Y direction similarly to the flow path substrate  32 , and the elements are bonded to each other using an adhesive, for example. 
     The nozzle plate  52  is a plate-shaped member on which the plurality of nozzles N are formed, and is provided on the second face F 2  of the flow path substrate  32  using an adhesive, for example. Each nozzle N is a through hole through which ink passes. The nozzle plate  52  is manufactured by processing a single crystal substrate of silicon (Si) using a semiconductor manufacturing technology (for example, etching). However, when manufacturing the nozzle plate  52 , it is possible to arbitrarily adopt a well-known material or manufacturing method. 
     The flow path substrate  32  is a plate-shaped member for forming a flow path of ink. A space R 1 , a plurality of supply holes  322  and a plurality of communicating holes  324  are formed in the flow path substrate  32 . The space R 1  is an opening which is formed in a long shape along the Y direction in a planar view (that is, when viewed in Z direction), and the supply holes  322  and the communicating holes  324  are through holes (opening which is formed over the first face F 1  and second face F 2 ) which are formed in each nozzle N. The plurality of supply holes  322  are arranged in the Y direction, and the plurality of communicating holes  324  are also formed in the Y direction, similarly. Arrangements of the plurality of supply holes  322  are located between arrangements of the plurality of communicating holes  324  and the space R 1 . In addition, as illustrated in  FIGS. 3 and 4 , a plurality of branching paths  326  which correspond to supply holes  322  which are different from each other are formed on the second face F 2  of the flow path substrate  32 . Each branching path  326  is a groove-shaped flow path which extends along the X direction so as to connect the space R 1  to the supply hole  322 . Meanwhile, one arbitrary communicating hole  324  overlaps one nozzle N in a planar view. That is, a nozzle N communicates with a communicating hole  324 . 
     As exemplified in  FIGS. 2 and 3 , the pressure chamber substrate  34  is a plate-shaped member on which a plurality of pressure chamber spaces  342  are arranged along the Y direction, and is provided on the first face F 1  of the flow path substrate  32  using an adhesive, for example. The pressure chamber space  342  is a long through hole which goes along the X direction in a planar view which is formed in each nozzle N. As illustrated in  FIG. 3 , an end portion on a positive side of one arbitrary pressure chamber space  342  in the X direction overlaps one communicating hole  324  of the flow path substrate  32  in a planar view. Accordingly, a pressure chamber space  342  and a nozzle N communicate with each other through the communicating hole  324 . 
     On the other hand, an end portion on the positive side of the pressure chamber space  342  in the X direction overlaps one supply hole  322  of the flow path substrate  32  in a planar view. As is understood from the above descriptions, since the supply hole  322  functions as a diaphragm flow path which causes the space R 1  and the pressure chamber space  342  to communicate at a predetermined flow path resistance, it is not necessary to form a diaphragm flow path in the pressure chamber substrate  34 . Therefore, a simple rectangular pressure chamber space  342  of which a width is maintained at a predetermined flow path width is formed in the pressure chamber substrate  34  according to the embodiment over the entire length in the X direction. That is, the diaphragm flow path in which a flow path area is partially constricted is not formed in the pressure chamber substrate  34 . Accordingly, it is possible to reduce a size of the pressure chamber substrate  34  compared to a configuration in which the diaphragm flow path is formed in the pressure chamber substrate  34 , and to realize miniaturization of the liquid ejecting head  100 . 
     The flow path substrate  32  and the pressure chamber substrate  34  are manufactured by processing a single crystal substrate of silicon (Si) using a semiconductor manufacturing technology, for example, similarly to the above described nozzle plate  52 . However, when manufacturing the flow path substrate  32  and the pressure chamber substrate  34 , it is possible to arbitrarily adopt a well-known material or manufacturing method. 
     As exemplified in  FIGS. 2 and 3 , the vibrating unit  36  is provided on the surface of the pressure chamber substrate  34  on a side opposite to the flow path substrate  32 . The vibrating unit  36  is a plate-shaped member (vibrating plate) which can be elastically vibrated. In addition, in  FIGS. 2 and 3 , a configuration in which the vibrating unit  36  which is separately formed from the pressure chamber substrate  34  is fixed to the pressure chamber substrate  34  is illustrated; however, it is also possible to integrally form the pressure chamber substrate  34  and the vibrating unit  36  by selectively removing a part of a region corresponding to the pressure chamber space  342  in the plate thickness direction, in a plate-shaped member with a predetermined plate thickness. 
     As is understood from  FIG. 3 , the first face F 1  of the flow path substrate  32  and the vibrating unit  36  face each other with an interval in the inside of each pressure chamber space  342  of the pressure chamber substrate  34 . A space between the first face F 1  of the flow path substrate  32  and the vibrating unit  36  in the inside of each pressure chamber space  342  functions as a pressure chamber SC for applying pressure to ink which is filled in the space. The pressure chamber SC is individually formed in each nozzle N. As is understood from the above descriptions, the pressure chamber space  342  formed in the pressure chamber substrate  34  is a space which is formed so as to be the pressure chamber SC. 
     As exemplified in  FIGS. 2 and 3 , the plurality of piezoelectric elements  37  which correspond to nozzles N which are different from each other are provided on a plane of the vibrating unit  36  on a side opposite to the pressure chamber SC. The piezoelectric element  37  is a passive element which is vibrated when a driving signal is supplied. The plurality of piezoelectric elements  37  are arranged in the Y direction so as to correspond to each pressure chamber SC. The piezoelectric element  37  is configured of a pair of electrodes which face each other, and a piezoelectric layer which is stacked between the electrodes. The protecting member  38  in  FIGS. 2 and 3  is a structure body for protecting the plurality of piezoelectric elements  37 , and is fixed to the surface of the vibrating unit  36  using an adhesive, for example. The plurality of piezoelectric elements  37  are accommodated in the inside of a space (recessed portion) which is formed on a face of the protecting member  38  which faces the vibrating unit  36 . 
     The housing  40  is a case for storing ink which is supplied to the plurality of pressure chambers SC. The surface of the housing  40  on the positive side in the Z direction (hereinafter, also referred to as “bonding face”) is fixed to the first face F 1  of the flow path substrate  32  using an adhesive, for example. The housing  40  is formed of a material which is different from that of the flow path substrate  32  or the pressure chamber substrate  34 . For example, it is possible to manufacture the housing  40  using injection molding, using a resin material, for example. However, when manufacturing the housing  40 , it is possible to arbitrarily adopt a well-known material or manufacturing method. 
       FIG. 5  is a plan view of the housing  40  which is viewed from the flow path substrate  32  side (positive side in Z direction). As exemplified in  FIGS. 3 and 5 , the housing  40  is a structure body in which a space R 2  is formed. The space R 2  is a recessed portion to which the flow path substrate  32  side is open, and is formed in a long shape in the Y direction. As illustrated in  FIG. 3 , for example, the space R 2  includes a first portion r 1  and a second portion r 2 . The first portion r 1  and the second portion r 2  intersect each other in a different direction. Specifically, the first portion r 1  extends in a direction parallel to the X-Y plane, and the second portion r 2  extends in a direction orthogonal to the X-Y plane. Since ink flows from the first portion r 1  toward the second portion r 2 , the second portion r 2  is a space on the downstream side in flowing of ink (the flow path substrate  32  side) when viewed from the first portion r 1 . In addition, an accommodating space  45  which accommodates the protecting member  38  and the pressure chamber substrate  34  is formed between a space R 2  corresponding to the first column L 1  and a space R 2  corresponding to the second column L 2 . 
     As exemplified in  FIGS. 2 and 3 , the housing  40  includes a top face portion  42  and a side face portion  44 . The side face portion  44  is a portion which is fixed to the first face F 1  so as to protrude from the first face F 1  on the negative side in the Z direction along the peripheral edge of the flow path substrate  32 . The base of the side face portion  44  is bonded to the first face F 1  of the flow path substrate  32  as a bonding face. As is understood from  FIG. 3 , an outer wall face of the side face portion  44  (surface on a side opposite to inner wall face on space R 2  side), and a side end face of the flow path substrate  32  are located on approximately the same plane (so-called flush surface). That is, an external shape of the flow path substrate  32  and an external shape of the housing  40  which are viewed in the Z direction practically match each other, and the external shape of the housing  40  does not protrude on the outer side of the outer peripheral edge of the flow path substrate  32 . Accordingly, there is an advantage that it is possible to miniaturize the liquid ejecting head  100  compared to a configuration in which the housing  40  is larger than the flow path substrate  32 . 
     The top face portion  42  of the housing  40  is a portion which is located on a side opposite to the flow path substrate  32  by interposing the space R 2  therebetween. A space which is surrounded with the side face portion  44  and the top face portion  42  corresponds to the space R 2 . As exemplified in  FIGS. 2 and 3 , an introducing port  43  is formed on the top face portion  42 . The introducing port  43  is a tubular portion which causes the space R 2  of the housing  40  and the outside of the housing  40  to communicate. As is understood from  FIG. 3 , the introducing port  43  is located on a side opposite to the side face portion  44  (negative side in X direction) by interposing the second portion r 2  of the space R 2  therebetween in a planar view, and communicates with the first portion r 1  in the space R 2 . 
     As exemplified in  FIG. 3 , the space R 1  of the flow path substrate  32  and the space R 2  of the housing  40  communicate with each other. A space which is formed by the space R 1  and the space R 2  functions as a liquid storage chamber (reservoir) SR. The liquid storage chamber SR is a common liquid chamber which extends over the plurality of nozzles N, and stores ink which is supplied to the introducing port  43  from the liquid container  14 . As described above, the introducing port  43  is located on the negative side of the second portion r 2  in the X direction. Accordingly, as illustrated in  FIG. 3  using a dashed arrow, ink which is supplied to the introducing port  43  from the liquid container  14  flows to the side face portion  44  side (positive side in X direction) in the first portion r 1  of the space R 2 , reaches the second portion r 2 , and flows to the positive side in the Z direction in the second portion r 2 . That is, a flow path which goes from the introducing port  43  toward the side face portion  44  side is formed in the housing  40 . In addition, ink which is stored in the liquid storage chamber SR is supplied to each pressure chamber SC in parallel, is filled in the pressure chamber by passing through the supply hole  322  after being branched off into the plurality of branching paths  326 , and is ejected to the outside from the pressure chamber SC by passing through the communicating hole  324  and the nozzle N due to a pressure change which corresponds to a vibration of the vibrating unit  36 . That is, the pressure chamber SC functions as a space in which a pressure for ejecting ink from the nozzle N is generated, and the liquid storage chamber SR functions as a space in which ink to be supplied to the plurality of pressure chambers SC is stored (common liquid chamber). 
     As exemplified in  FIGS. 2 and 3 , the compliance unit  54  is provided on the second face F 2  of the flow path substrate  32 . The compliance unit  54  is a flexible film, and functions as a vibration absorbing body which absorbs a pressure change of ink in the liquid storage chamber SR (space R 1 ). As illustrated in  FIG. 3 , the compliance unit  54  configures a base of the liquid storage chamber SR by being provided on the second face F 2  of the flow path substrate  32  so as to seal the space R 1  of the flow path substrate  32 , the plurality of branching paths  326 , and the plurality of communicating holes  324 . That is, the pressure chamber SC faces the compliance unit  54  through the communicating hole  324 . In addition, in the illustration in  FIG. 2 , a space R 1  corresponding to the first column L 1  and a space R 1  corresponding to the second column L 2  are sealed with a separate compliance unit  54 ; however, it is also possible to cause one compliance unit  54  to be continuous over both of the spaces R 1 . 
     Meanwhile, as exemplified in  FIGS. 2 and 3 , an opening portion  422  is formed on the top face portion  42  of the housing  40 . Specifically, the opening portions  422  are formed on the positive side and the negative side in the Y direction by interposing the introducing port  43  therebetween. The opening portion  422  is an opening which causes the space R 2  of the housing  40  and an external space of the housing  40  to communicate. As illustrated in  FIG. 2 , a compliance unit  46  is provided on the surface of the top face portion  42 . The compliance unit  46  is a flexible film which functions as a vibration absorbing body which absorbs a pressure change of ink in the liquid storage chamber SR (space R 2 ), and configures a wall face (specifically, ceiling) of the liquid storage chamber SR by being provided on the outer wall face of the top face portion  42  so as to seal the opening portion  422 . The compliance unit  46  is located on the upstream side of the compliance unit  54  in the liquid storage chamber SR, and is arranged in parallel to the first face F 1  of the flow path substrate  32  or the compliance unit  54 . In addition, in the illustration in  FIG. 2 , an individual compliance unit  46  is provided in each opening portion  422 ; however, it is also possible to adopt a configuration in which one compliance unit  46  is continuous over the plurality of opening portions  422 . As is understood from the above descriptions, according to the first embodiment, the compliance units  54  and  46  are provided in order to suppress a pressure change in the liquid storage chamber SR. 
     As illustrated in  FIG. 3 , a plurality of beam-shaped units  48  are formed in the second portion r 2  of the space R 2  of the housing  40 .  FIGS. 4 and 5  are explanatory diagrams of the beam-shape unit  48 . The upper part of  FIG. 4  is a sectional view taken along line IV-IV of  FIG. 2  when the housing  40  is viewed in the Z direction, and the lower part of  FIG. 4  is a sectional view taken along line V-V of the upper part of  FIG. 4  when the housing  40  is viewed from the positive side in the X direction.  FIG. 5  is a perspective view enlargedly illustrating the beam-shaped unit  48 , and enlargedly illustrates one corner portion Q of the housing  40  illustrated in  FIG. 4 . As illustrated in  FIGS. 4 and 5 , the beam-shaped units  48  are a plurality of beam-shaped portions of the second portion r 2  of the space R 2  which are stretched over a pair of inner wall faces  472  facing each other. That is, the beam-shaped unit  48  is formed in a shape which reaches the other side from one side of the pair of inner wall faces  472  which are parallel to an Y-Z plane in the second portion r 2 , among the inner wall faces  47  of the space R 2 , by protruding in the X direction. The plurality of beam-shaped units  48  are provided with intervals in the Y direction, in the second portion r 2  of the space R 2 . The beam-shaped unit  48  can be integrally formed with the housing  40  using injection molding, using a resin material, for example. However, the beam-shaped unit  48  may be configured to be a separate member from the housing  40  and be fixed to the housing  40 . 
     The surface of the beam-shaped unit  48  on the flow path substrate  32  side is an inclined face which is inclined to the first face F 1  (X-Y plane) of the flow path substrate  32 . Specifically, the surface of the beam-shaped unit  48  on the flow path substrate  32  side includes a pair of inclined faces (planar face or curved face)  482  which are located on the positive side and the negative side in the Y direction by having a ridgeline  481  along the X direction as a boundary. That is, a horizontal width (dimension in Y direction) of the beam-shaped unit  48  gradually decreases from the negative side to the positive side in the Z direction. 
     The plurality of beam-shaped units  48  are provided at a position which is separated from the first face F 1  of the flow path substrate  32  on the negative side in the Z direction (side opposite to flow path substrate  32 ), and the surfaces (upper faces) of the plurality of beam-shaped units  48  on the negative side in the Z direction are located on approximately the same plane (so-called flush surface) as the inner wall face (the surface on a side opposite to the compliance unit  46 ) of the first portion r 1  of the space R 2 . The space R 2  of the housing  40  is divided into a space (first portion r 1 ) on the upstream side of the plurality of beam-shaped units  48  and a space (space on the downstream side of the beam-shaped unit  48  in the second portion r 2 ) on the downstream side of the plurality of beam-shaped units  48 , by the plurality of beam-shaped units  48 . In addition, the plurality of beam-shaped units  48  are disposed with intervals such that a plurality of flow paths P having the Z direction as the flow path direction are arranged on the negative side and the positive side in the Y direction from the introducing port  43 . Accordingly, as indicated by arrows in  FIG. 4 , the ink introduced through the introducing port  43  flows from the first portion r 1  to the second portion r 2  by passing through the flow path P between the beam-shaped units  48 . The number of beam-shaped units  48  and the number of a plurality of flow paths P are not limited to the example in the drawing. 
     As described above, in the embodiment, since the beam-shaped unit  48  is disposed in the space R 2  of the housing  40 , it is possible to improve the mechanical strength of the housing  40 . Meanwhile, if the flow paths P are divided by the beam-shaped units  48 , performances of discharging bubbles may be decreased. Thus, in the embodiment, the dimensions of respective flow paths P formed by the beam-shaped units  48  are set as follows. That is, if among the plurality of flow paths P formed by the beam-shaped units  48 , the flow paths P far away from the introducing port  43  in the Y direction (first direction) are set as first flow paths, and the flow paths P close to the introducing port  43  are set as second flow paths, a flow path width W of each flow path P is set such that the first flow path has a flow path width W in the Y direction smaller than that of the second flow path. The flow path width W corresponds to an interval between two beam-shaped units  48  that are adjacent in the Y direction. 
     Specifically, as illustrated in  FIG. 4 , in the embodiment, the flow path widths are set as W 1  to W 5  from the flow paths P close to the introducing port  43  to the flow paths P far away from the introducing port  43 , the flow path widths W 5  of the flow paths P farthest from the introducing port  43  (that is, the flow paths P located on end portions in the Y direction) are smaller than the flow path widths W 1  to W 4  of the flow paths P that are closer to the introducing port  43  than the farthest flow paths P. In  FIG. 4 , the flow path widths W 1  to W 4  are the same as each other. However, the flow path widths W 1  to W 4  may be set such that the flow paths P far away from the introducing port  43  have flow path widths in the Y direction smaller than those of the flow paths P close to the introducing port  43 . 
     In the embodiment, both the flow path width W in the X direction and a flow path width D in the Y direction of each flow path P are smaller than a height H in the Z direction (third direction) of the first portion r 1  on the upstream side of the beam-shaped unit  48 . The flow path width D corresponds to an interval between the pair of inner wall faces  472  facing each other in the space R 2 , and can be called a length of the beam-shaped unit  48  in the X direction. 
       FIG. 6  is an explanatory diagram illustrating operations of the liquid ejecting head  100  according to the embodiment, and is a part of the cross-sectional view of the lower part of  FIG. 4 .  FIG. 7  is an explanatory diagram illustrating operations of a liquid ejecting head  100 ′ according to a comparative example. In the comparative example of  FIG. 7 , all the flow path widths of the flow paths P of  FIG. 6  are the same dimension W′. Accordingly, in the comparative example, the flow path width W′ of the flow path P farthest from the introducing port  43  is larger than the flow path width W 5  of the embodiment. Even in the comparative example of  FIG. 7 , similar to the embodiment of  FIG. 6 , the ink introduced through the introducing port  43  flows in the first portion r 1  of the space R 2  toward the positive side and the negative side in the Y direction, passes through the flow paths P formed by the beam-shaped units  48 , and flows to the second portion r 2  of the space R 2 . As illustrated in  FIGS. 6 and 7 , the bubble B mixed in the ink moves to reach the corner portion Q of the space R 2  in accordance with the flow of the ink. 
     In the configuration in which the flow path width W′ in the Y direction of the flow path P is large as in the comparative example of  FIG. 7 , a gap is generated between the bubble B moved to the corner portion Q and the surface of the beam-shaped unit  48  (the inner wall face of the flow path P), and ink passes (leaks) through this gap. Accordingly, as understood from  FIG. 7 , the bubble B is pressed against the corner portion Q to stay due to the ink passing through the gap, and the bubble B becomes difficult to be discharged from the space R 2 . As the flow path P is farther from the introducing port  43 , the flow rate of the ink becomes reduced, and therefore, the tendency that the bubble B is difficult to be discharged becomes remarkable. 
     Meanwhile, in the embodiment of  FIG. 6 , since the flow path width W 5  is smaller than the flow path width W′ of the comparative example of  FIG. 7 , a gap is unlikely to be generated between the bubble B and the surface of the beam-shaped unit  48  (the inner wall face of the flow path P). That is, as understood from  FIG. 6 , the flow path P is temporarily blocked by the bubble B having reached the vicinity of the corner portion Q. Accordingly, a pressure difference is generated between the upstream side (the first portion r 1 ) and the downstream side (the second portion r 2 ) of the corresponding flow path P, and as a result, the bubble B is easily discharged through the flow path P. Furthermore, the flow rate of the ink is increased by setting the flow path width W 5  of flow path P, which is a position where the speed of the ink from the introducing port  43  is easily decreased, to be small, and thus the bubble B is easily discharged. 
     In consideration of the view point of promoting the discharge of the bubble B by suppressing the formation of the gap, a configuration in which all the plurality of flow paths P have small flow path widths W can be assumed. However, in such a configuration in which the flow path widths W are small, the flow rate of the ink from the space R 1  to the space R 2  is limited, and as a result, the supply of the ink to each pressure chamber SC may be insufficient. In consideration of such a circumstance, in the embodiment, the configuration is adopted in which the flow path P close to the introducing port  43  has the flow path width W larger than that of the flow path P far away from the introducing port  43 . That is, the flow path width W of the flow path P close to the introducing port  43  (that is, at a position where the bubble B is unlikely to stay) is sufficiently secured while the flow path width W of the flow path P on the downstream side (end portion side in the Y direction) where the bubble B easily stays is reduced. Accordingly, it is possible to easily discharge the bubble in the flow path P far from the introducing port  43  while securing the flow rate of the ink in the flow path P close to the introducing port  43 . 
     In the embodiment, the flow path width D in the Y direction of the flow path P is smaller than the height H in the Z direction (third direction) of the first portion r 1  on the upstream side of the beam-shaped unit  48 . According to such a configuration, since the flow path area of the flow paths P is reduced compared to the configuration in which the flow path width D is larger than the height H, it is possible to increase the flow rate of the ink passing through the flow path P. In addition, it is possible to promote the discharge of the bubble B through the flow path P. Since the height H greater than the flow path width D is secured in the first portion r 1 , there is an advantage in that the flow rate of the ink flowing in a space (the first portion r 1 ) on the upstream side of the beam-shaped unit  48  is easily secured. 
     In the embodiment, the flow path width W 5  of the flow path P in the X direction as well as the flow path width D of the flow path P in the Y direction is smaller than the height H of the first portion r 1  in the Z direction. That is, both the flow path width D in the Y direction and the flow path width W 5  in the X direction of the flow path P far away from the introducing port  43  are reduced, and thus the flow path area of the flow path P can be reduced. Accordingly, the effect in which it is possible to promote the discharge of the bubble B by the suppression of the gap between the bubble B and the inner wall face of the flow path P, and by the increase of the flow rate of the ink is particularly remarkable. 
     The flow path width W 5  of the flow path P in the X direction is smaller than the height H of the first portion r 1  and the flow path width D in the Y direction may be greater than the height H. Even in such a configuration, it is possible to promote the discharge of the bubble B by increasing the flow rate of the ink flowing through the flow path P while the flow rate of the ink flowing through the first portion r 1  is secured. In the embodiment, the case in which all the flow paths P have the same height H in the Z direction (third direction) of the first portion r 1  on the upstream side of the beam-shaped unit  48  is described, but the heights H of the first portion r 1  may be different from each other depending on the position of the flow path P. For example, the height H of the first portion r 1  corresponding to the flow path P farthest from the introducing port  43  may be smaller than the heights H of other flow paths P. Specifically, a configuration in which the flow path width D of the flow path P in the Y direction and the flow path width W 5  of the flow path P in the X direction are smaller than the height H of the flow path P farthest from the introducing port  43  is preferable. 
     In the embodiment, the space R 2  of the liquid storage chamber SR includes the first portion r 1  parallel to the X-Y plane and the second portion r 2  orthogonal to the plane from the introducing port  43 , and the beam-shaped unit  48  is formed in the second portion r 2  orthogonal to the plane. According to such a configuration, when the ink flows from the first portion r 1  to the second portion r 2  in the space R 2  of the liquid storage chamber SR, since the ink passes through the flow path P formed by the beam-shaped unit  48 , at this time, it is possible to easily discharge the bubble B in the flow path P far away from the introducing port  43  while the flow rate of the liquid is secured. 
     In the embodiment, since the liquid storage chamber SR and the pressure chamber SC communicate through the supply hole  322  (diaphragm flow path) which is formed in the flow path substrate  32 , it is possible to reduce a size of the pressure chamber substrate  34  compared to a configuration in which the diaphragm flow path is formed in the pressure chamber space  342 . Accordingly, it is possible to realize miniaturization of the liquid ejecting head  100 . In addition, since the compliance unit  54  is provided in the vicinity of the pressure chamber SC so as to face the pressure chamber SC by interposing the communicating hole  324 , there is an advantage that it is possible to efficiently absorb a pressure change which is propagated to the liquid storage chamber SR from each pressure chamber SC through the communicating hole  324  using the compliance unit  54 . Meanwhile, in a configuration in which the flow path substrate  32  is reduced in size in order to miniaturize the liquid ejecting head  100 , it is difficult to sufficiently secure an area of the compliance unit  54 , and a possibility that a pressure change in the liquid storage chamber SR may not be sufficiently suppressed using only the compliance unit  54  is also assumed. According to the embodiment, since the compliance unit  46  is provided in the housing  40 , in addition to the compliance unit  54  of the flow path substrate  32 , there is an advantage that it is possible to effectively suppress a pressure change in the liquid storage chamber SR even when the flow path substrate  32  is miniaturized compared to a configuration in which the compliance unit  46  is not provided. 
     Meanwhile, it is necessary to miniaturize the housing  40 , as well, in order to miniaturize the liquid ejecting head  100 ; however, when the plate thickness of the side face portion  44  or the top face portion  42  is reduced in order to miniaturize the housing  40 , there is a possibility that a mechanical strength of the housing  40  may be insufficient. According to the embodiment, since the beam-shaped unit  48  is provided in the housing  40 , there is an advantage that it is possible to maintain the mechanical strength of the housing  40  even in a configuration in which the plate thickness of each unit is reduced in order to miniaturize the housing  40 . 
     Modification Example 
     Each embodiment which is exemplified above can be variously modified. Specific modification example will be described below. Two or more examples which are arbitrarily selected from the following examples can be appropriately combined in a range of not conflicting each other. 
     (1) In each embodiment described above, a case where the space R 2  of the liquid storage chamber SR where the beam-shaped unit  48  is provided is configured to be divided into the first portion r 1  and the second portion r 2  intersecting in different directions is described. However, the first portion r 1  and the second portion r 2  may be integrally configured so as to communicate with each other in the same direction without intersecting each other. 
     (2) In each embodiment described above, one housing  40  is provided with respect to one flow path substrate  32 ; however, it is also possible to provide one housing with respect to a plurality of the flow path substrates  32 . 
     (3) In each embodiment described above, the compliance unit  46  is provided on the top face portion  42  of the housing  40 ; however, it is possible to provide the compliance unit on the side face portion  44  of the housing  40 . In this case, it is possible to provide the compliance unit  46  on both the top face portion  42  and the side face portion  44  of the housing  40 . 
     (4) The element (driving element) which applies a pressure into the pressure chamber SC is not limited to the piezoelectric element  37  which is exemplified in each embodiment which is described above. For example, it is also possible to use a heating element which causes a pressure change by generating bubbles in the inside of the pressure chamber SC using heating, as a driving element. As is understood from the above examples, the driving element is comprehensively expressed as an element for ejecting liquid (typically, element which applies pressure into pressure chamber SC), and an operation method (piezoelectric method or heating method) or specific configuration thereof does not matter. 
     (5) In each embodiment which is described above, a serial head in which the carriage  26  on which the plurality of liquid ejecting heads  100  are mounted moves in the X direction is exemplified; however, it is also possible to apply the invention to a line head in which a plurality of liquid ejecting heads  100  are arranged in the X direction. 
     (6) The printing apparatus  10  which is exemplified in each embodiment which is described above can be adopted to various devices such as a fax machine or a copy machine, in addition to a device which is exclusive to printing. Originally, a use of the liquid ejecting apparatus in the invention is not limited to printing. For example, a liquid ejecting apparatus which ejects a solution of a coloring material is used as a manufacturing device which forms a color filter of a liquid crystal display device. In addition, a liquid ejecting apparatus which ejects a solution of a conductive material is used as a manufacturing device which forms wiring or an electrode of a wiring substrate. 
     The entire disclosure of Japanese Patent Application No. 2015-188416, filed Sep. 25, 2015 is expressly incorporated by reference herein in its entirety.