Patent Publication Number: US-9421769-B2

Title: Liquid ejecting head, liquid ejecting head unit, liquid ejecting apparatus, and method of manufacturing liquid ejecting head unit

Description:
BACKGROUND 
     1. Technical Field 
     The present invention relates to a liquid ejecting head that ejects a liquid from a nozzle, a liquid ejecting head unit that is provided with a plurality of the liquid ejecting heads, a liquid ejecting apparatus that is provided with the liquid ejecting head unit, and a method for manufacturing a liquid ejecting head unit. 
     2. Related Art 
     Liquid ejecting apparatuses are apparatuses that are provided with a liquid ejecting head that is capable of ejecting a liquid as liquid droplets from a nozzle, and that ejects various liquids from the liquid ejecting head. As a representative example of this kind of liquid ejecting apparatus, it is possible to include an image recording apparatus such as an ink jet type recording apparatus (printer) that is provided with an ink jet type recording head (hereinafter, referred to as a recording head) and performs recording by ejecting liquid ink (in the form of ink droplets) from a nozzle of the recording head. Further, in addition to the above, liquid ejecting apparatuses are used in the ejecting of various types of liquid such as color materials that are used in color filters for liquid crystal displays and the like, organic materials that are used in organic EL (Electro Luminescence) displays, and electrode materials that are used in electrode formation. Further, liquid ink is ejected in recording heads for image recording apparatuses, and solutions of the respective color materials of R (Red), G (Green) and B (Blue) are ejected from color material ejecting heads for display manufacturing apparatuses. In addition, liquid electrode material is ejected from electrode material ejecting heads for electrode formation apparatuses, and solutions of living organic matter are ejected from living organic matter ejecting heads for chip manufacturing apparatuses. 
     As a printer such as that mentioned above, there is a printer that is equipped with a recording head unit in which a plurality of recording heads are fixed to a support member (for example, refer to JP-A-2008-194972). Each recording head introduces ink from an ink supply source (such as an ink cartridge) into a pressure chamber (pressure generation chamber). Each recording head generates a pressure variation in the ink inside the pressure chamber by operating pressure generation means, such as a piezoelectric element or a heater element. Each recording head is further configured to eject the ink inside the pressure chamber (in the form of ink droplets) from a nozzle (which is open on a nozzle surface) using the pressure variation. In addition, in a state in which the nozzle surface of each recording head is exposed from an opening of the support member, each recording head is fixed to the edge of the opening by a screw or the like. 
     In the above-described configuration, it is necessary to fix each recording head to the support member in a state in which the relative position thereof is stipulated with high accuracy. This is to land the liquid droplets (that are ejected from each recording head) with higher positional accuracy on a landing target such as a recording medium. In particular, there are cases where the ink ejecting characteristics (for example, the skew of ink droplets during flight or the like) of each recording head differ respectively. Therefore, in that case, it is necessary to perform position adjustment considering the ejecting characteristics for each recording head. However, the work for respectively adjusting the installation position of each recording head when fixing each recording head to the support member is troublesome. In addition, for example, in a case where a single recording head is exchanged during repair or the like, it is necessary to perform readjustment of the installation position when fixing the recording head to the support member again. This leads to a deterioration in the rate of operation. 
     SUMMARY 
     An advantage of some aspects of the invention is that it provides a liquid ejecting head that is capable of improving the installation workability when installing liquid ejecting heads in support members, a liquid ejecting head unit, a liquid ejecting apparatus and a method of manufacturing a liquid ejecting head unit. 
     According to an aspect of the invention, there is provided a liquid ejecting head main body that has a nozzle group that is formed by arranging a plurality of nozzles, which eject a liquid, in parallel, to eject a liquid from each nozzle; and a fixation member to which the liquid ejecting head main body is fixed, in which the fixation member has a fixation part to which the liquid ejecting head main body is fixed, and a reference surface that is formed on a side opposite the fixation part, and includes a reference part serving as a reference for positioning the liquid ejecting head main body with respect to an installation target, and a position adjusting part for adjusting the relative position between the reference surface and the nozzle group is provided between the liquid ejecting head main body and the fixation part. 
     According to this configuration, it is possible to prepare a liquid ejecting head in which the relative position between the reference surface and the liquid ejecting head main body is adjusted in advance. Therefore, for example, by merely defining the relative position of the reference surface for the support member when fixing the liquid ejecting head to the support member, that is, by merely bring the reference part into contact with the support member, it is possible to accurately define the relative position of the liquid ejecting head main body. As a result, the work to correct positional deviation of a liquid ejecting head main body that is fixed to the support member is not necessary, and it is possible to improve the workability when installing the liquid ejecting head in the support member. 
     In the above-described configuration, it is desirable that the relative position of the nozzle group for the reference surface be adjusted based on a pattern that is formed on a landing target by ejecting a liquid from each nozzle of the liquid ejecting head main body. 
     According to this configuration, it is possible to perform position adjustment of the liquid ejecting head main body in consideration of the liquid-ejecting characteristics (for example, the skew of ink droplets during flight or the like) of the liquid ejecting head main body. Therefore, it is possible to more accurately define the relative position of the liquid ejecting head main body for the support member. 
     In addition, in the above-described configuration, it is desirable that the nozzle group be configured by a nozzle string in which the nozzles are lined up in a straight line, and the relative position of the nozzle string is adjusted so that a linear pattern formed on the landing target by ejecting a liquid from the nozzle string in a direction along the reference surface, and a reference line of which the relative position with respect to the reference surface is defined, are parallel. 
     According to this configuration, it becomes easier to adjust the relative position between the reference surface and the nozzle group. Additionally, the term “nozzle string” mentioned here is not limited to a nozzle string in which the nozzles are lined up in a straight line, and for example, includes a nozzle string in which the nozzles are arranged diagonally with respect to the reference surface, and a so-called two-dimensional arrangement type nozzle string in which the nozzles are arranged in a direction parallel to the reference surface and in which nozzles are alternately shifted in a direction perpendicular to the arrangement direction. In addition, the term “parallel” mentioned here includes a case of being slightly shifted from a parallel state within an allowable error margin of the specifications of the product. 
     Furthermore, according to another aspect of the invention, there is provided a liquid ejecting head unit including the liquid ejecting head of the invention, and a support member in which the liquid ejecting head is installed using the fixation member, in which the support member has an installation surface that defines an installation position of the fixation member in the support member. 
     According to this configuration, by merely defining the relative position between the installation surface and the reference surface when fixing the liquid ejecting head to the support member, it is possible to accurately define the relative position of the liquid ejecting head main body for the support member. As a result, the work to correct a positional deviation of a liquid ejecting head main body that is fixed to the support member is not necessary, and it is possible to improve the workability when installing the liquid ejecting head in the support member. 
     In addition, in the above-described configuration, it is desirable that the support member and the fixation member be positioned by bring the installation surface into contact with the reference part. 
     According to this configuration, it is possible to easily define the relative position of the liquid ejecting head main body for the support member. As a result, it is possible to improve the workability when installing the liquid ejecting head in the support member. 
     Further, according to still another aspect of the invention, there is provided a liquid ejecting apparatus including the liquid ejecting head unit. 
     In addition, according to still another aspect of the invention, there is provided a method of manufacturing a liquid ejecting head unit including a liquid ejecting head that is provided with a liquid ejecting head main body that has a nozzle group that is formed by arranging a plurality of nozzles, which eject a liquid, in parallel, to eject a liquid from each nozzle, and a fixation member that has a fixation part to which the liquid ejecting head main body is fixed, and a reference surface that is formed on a side opposite to the fixation part, and which includes a reference part serving as a reference for positioning the liquid ejecting head main body with respect to an installation target; and a support member that has an installation surface in which the liquid ejecting head is installed using the fixation member, the method including adjusting the relative position between the nozzle group of the liquid ejecting head main body and the reference surface of the fixation member; fixing the fixation member and the liquid ejecting head main body by positioning a position adjusting part between the liquid ejecting head main body and the fixation part in a state in which the nozzle group has been positioned with respect to the reference surface; and fixing the support member and the fixation member to each other in a state of being positioned with respect to the support member by bring the reference part of the fixation member into contact with the installation surface of the support member. 
     Furthermore, it is desirable that the adjusting of the relative position includes forming a pattern on a landing target by ejecting a liquid from each nozzle of the liquid ejecting head main body; and adjusting the relative position of the nozzle group with respect to the reference surface based on the pattern. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIGS. 1A and 1B  are schematic diagrams illustrating a configuration of a printer, in which  FIG. 1A  is a plan view and  FIG. 1B  is a side view. 
         FIG. 2  is a perspective view of a head unit viewed from a nozzle surface side. 
         FIGS. 3A and 3B  are schematic diagrams illustrating a configuration of a head unit, in which  FIG. 3A  is a front view and  FIG. 3B  is a bottom view. 
         FIGS. 4A and 4B  are schematic diagrams illustrating a configuration of a base plate, in which  FIG. 4A  is a front view and  FIG. 4B  is a bottom view. 
         FIGS. 5A and 5B  are perspective views schematically illustrating a configuration of a unit head, in which  FIG. 5A  is a perspective view of a state in which a fixation member is installed, and  FIG. 5B  is a perspective view of a state in which a fixation member is removed. 
         FIG. 6  is a cross-sectional view of the main parts of a unit head main body. 
         FIGS. 7A and 7B  are schematic diagrams illustrating a configuration of a fixation member, in which  FIG. 7A  is a front view and  FIG. 7B  is a bottom view. 
         FIGS. 8A to 8E  are schematic diagrams illustrating a method of manufacturing a head unit. 
         FIGS. 9A and 9B  are schematic diagrams illustrating a method of manufacturing a head unit. 
         FIG. 10  is a bottom view of a fixation member in another embodiment. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Additionally, in the embodiments that are described below, various limitations are given as preferred specific examples of the present invention. However, the scope of the invention is not limited to these aspects unless a feature that limits the present invention is particularly stated in the following description. In addition, in the following description, an ink jet type printer (hereinafter, referred to as a printer  1 ) is used as an example of a liquid ejecting apparatus of the invention. In the printer  1 , there are mounted a plurality of ink jet recording heads (hereinafter, referred to as unit heads  7 ), which are a type of liquid ejecting head. 
       FIG. 1A  is a plan view schematically illustrating a configuration of a printer  1 .  FIG. 1B  is a side view of the printer  1 . The printer  1  is provided with a head unit  2  (corresponding to the liquid ejecting head unit in the invention), an ink tank  3 , a paper supply roller  4  and a transport mechanism  5 . The head unit  2  is a device in which a plurality of unit heads  7  are arrayed, which unit heads  7  perform recording of images or the like by ejecting a liquid ink, are arranged. The head unit  2  extends in an oblong manner along a paper width direction (a direction perpendicular to a transport direction of recording paper  6 ) of recording paper  6  (a sort of recording medium or landing object). The ink tank  3  is a sort of storage member (a liquid supply source) in which ink is stored for supply to the head unit  2 . The ink that is inside the ink tank  3  is supplied to the head unit  2  through an ink supply tube  8 . Additionally, it is possible to employ a configuration in which the liquid supply source is equipped with above the head unit  2 . In addition, a specific configuration of the head unit  2  will be described later. 
     The paper supply roller  4  is arranged upstream of the transport mechanism  5 , and is configured by an upper and lower pair of rollers  4   a  and  4   b  that are synchronously rotatable in directions opposite to each other with the recording paper  6  interposed therebetween and supplied from a paper feeding section (not illustrated). The paper feeding roller  4  is driven by power from a paper feeding motor  9 , and supplies the recording paper  6  to a transport mechanism  5  side after correcting a tilt of the recording paper  6  with respect to the transport direction and a positional deviation thereof in a direction (the paper surface direction of the recording paper  6 ) perpendicular to the transport direction by causing skew correction rollers (not illustrated) to collaborately operate. 
     The transport mechanism  5  is provided with a transport belt  11 , a transport motor  12 , a drive roller  13 , a driven roller  14 , a tension roller  15  and a pressure contact roller  16 . The transport motor  12  is a drive source of the transport mechanism  5 , and conveys power to the drive roller  13 . The transport belt  11  is an endless belt, and is stretched tightly between the drive roller  13  and the driven roller  14 . The tension roller  15  is in contact with an inner peripheral surface of the transport belt  11  between the drive roller  13  and the driven roller  14 , and applies a tensile force to the transport belt  11  using a biasing force of a biasing member such as a spring. The pressure contact roller  16  is disposed directly above the driven roller  14  with the transport belt  11  interposed therebetween, and presses the recording paper  6  on the transport belt  11 . 
     A linear scale  18  is disposed over the entire circumference of the belt on an outer peripheral surface of the transport belt  11 . The linear scale  18  is configured by arranging a plurality of slit-shaped patterns for detection at regular intervals (for example, 360 per linear inch) in a transport direction of the transport belt  11 . The patterns for detection of the linear scale  18  are detected optically by a detection head  19 , and detected signals are output as encoder signals to a control unit (not illustrated) of the printer  1 . Therefore, based on the encoder signal, the control unit can ascertain the amount that the recording paper  6  has been transported using the transport mechanism  5  (the transport belt  11 ). In addition, the encoder signal defines a generation timing of the drive signal for driving a piezoelectric element  65  (to be described later) of the unit heads  7 . 
     Next, the head unit  2  will be described with reference to the drawings.  FIG. 2  is a perspective view of the head unit  2  viewed from the side of a nozzle surface  45  (a side of a nozzle plate  39 , refer to  FIG. 6 ). In addition,  FIGS. 3A and 3B  are schematic diagrams illustrating a configuration of the head unit  2 .  FIG. 3A  is a front view of the head unit  2  and  FIG. 3B  is a bottom view of the head unit  2 . Furthermore,  FIGS. 4A and 4B  are schematic diagrams illustrating a configuration of a base plate  23 .  FIG. 4A  is a front view of the base plate  23  and  FIG. 4B  is a bottom view of the base plate  23 . 
     The head unit  2  in the present embodiment is configured by installing a plurality of unit heads  7  (corresponding to liquid ejecting heads in the invention) in a base plate  23  (corresponding to a support member in the invention). In the present embodiment, four unit heads  7  respectively sandwich the base plate  23  and are installed in each side thereof. That is, a total of eight unit heads  7  are installed in the base plate  23 . The unit heads  7  are lined up at equivalent or regular intervals along a longitudinal direction of the base plate  23 . Further, a row of the unit heads  7  that is lined up on a first side of the base plate  23  and a row of the unit heads  7  that is lined up on a second side thereof are lined up so as to be shifted by a distance of half the lining-up pitch of the unit heads  7 . 
     The base plate  23  is a plate material that is elongated in a parallel arrangement (lining-up) direction (or a nozzle string direction) of the unit heads  7 , and for example, is made of a metal such as stainless steel. As illustrated in  FIGS. 4A and 4B , a storage section  24  (in which a part of the unit head  7  is stored) is provided in a position that corresponds to the unit head  7  on the surface of each side of the base plate  23 . That is, the storage section  24  is provided at each installation position of the unit head  7  of the base plate  23 , and thus a total of eight storage sections  24  are collectively formed on both sides thereof. The storage section  24  includes flat installation surfaces  25  that are depressed from one side surface of the base plate  23  toward the other side surface. The storage section  24  allows the unit head  7  (a reference part  60  of a fixation member  33 ) to be installed therein. The storage section  24  further includes a vacancy  26  that is further depressed from the installation surfaces  25  toward the other side surface. The storage section  24  also includes receiving surfaces  27  that are perpendicular to the installation surfaces  25 . In addition, the storage section  24  is provided with a ceiling  28  that is formed from a lower end of the base plate  23  to the middle in the height direction of the base plate (the height direction being a direction perpendicular to the nozzle surface  45 ). An upper end of the storage section  24  is in contact with an upper end of the unit head  7 . In the present embodiment, a depth (a dimension in the thickness direction of the base plate  23 ) of the storage section  24  is formed to be smaller than a thickness (a dimension in the same direction) of the unit head  7 , and a height of the storage section  24  is formed to be smaller than a height of the unit head  7 . For this reason, as illustrated in  FIGS. 3A and 3B , in a state in which the unit head  7  is installed in the storage section  24 , the front part (a side opposite the base plate  23 ) of the unit head  7  protrudes forward from the base plate  23 , and the lower end (the nozzle surface  45 ) of the unit head  7  is exposed from the lower end of the base plate  23 . Further, a dimension of the storage section may be formed to match a dimension of the unit head so that the unit head does not protrude from the storage section. 
     As illustrated in  FIG. 4B , the installation surfaces  25 , which define an installation position of the fixation member  33  (to be described later) for the base plate  23 , are surfaces perpendicular to the nozzle surface  45 . The installation surfaces  25  are provided on both sides with the vacancy  26  interposed therebetween in the storage section  24  in the parallel arrangement direction of the unit heads  7 . As illustrated in  FIG. 4A , screw holes  29  are respectively opened in the installation surfaces  25  on both sides, and thus the unit head  7  is installed using screws. Here, the installation surfaces  25  are in contact with the reference part  60  of the unit head  7  (fixation member  33 ) and serve as a positioning reference of the unit head  7 , that is, required to have high flatness, and thus preferably have a small area. For this reason, the installation surfaces  25  of the present embodiment are made to have as small an area as possible in the storage section  24 , thereby increasing positioning accuracy. Specifically, in a front view, an area of the installation surfaces  25  is smaller than an area of the vacancy  26 . In addition, the vacancy  26  is set to have a depth which prevents the unit head  7  from being in contact with an inner wall surface forming the vacancy  26  when the unit head  7  is installed on the installation surfaces  25 . Accordingly, the installation surfaces  25  function as surfaces defining a position of the unit head  7 . In addition, in the present embodiment, the part of the unit head  7  opposing the vacancy  26  is formed to be coplanar with a reference surface  58 . Thus, it is not necessary to considerably depress the vacancy  26  further toward the other surface side as compared to the installation surfaces  25 . For this reason, the vacancy  26  of the present embodiment is formed to be slightly depressed further toward the other surface side than the installation surfaces  25 . Accordingly, a sufficient thickness of the base plate  23  can be obtained, thus enabling increased strength of the base plate  23 . 
     The receiving surfaces  27  form inner walls of both ends of the storage section  24  in the parallel arrangement direction of the unit heads  7 , and are perpendicular to the installation surfaces  25  and the nozzle surface  45 . A gap (that is, a width of the storage section  24  in the parallel arrangement direction of the unit heads  7 ) between one receiving surface  27  and the other receiving surface  27  is aligned with the width of the unit head  7  stored in the storage section  24  and defines a position of the unit head  7  in the parallel arrangement direction of the unit heads  7 . In addition, the ceiling  28  is a surface parallel to the nozzle surface  45 , and defines a position of the unit head  7  in the height direction. 
       FIGS. 5A and 5B  are schematic diagrams illustrating a configuration of the unit head  7 .  FIG. 5A  is a perspective view illustrating a state in which the fixation member  33  is installed.  FIG. 5B  is a perspective view illustrating a state in which the fixation member  33  is not installed. In addition,  FIG. 6  is a cross-sectional view of a main part of a unit head main body  32 . Further,  FIGS. 7A and 7B  are schematic diagrams illustrating a configuration of the fixation member  33 , in which  FIG. 7A  is a front view of the fixation member  33 , and  FIG. 7B  is a bottom view of the fixation member  33 . In  FIG. 6 , a configuration of a main part corresponding to the other nozzle string  42  is horizontally symmetrical to the illustrated configuration, and thus is not illustrated. 
     The unit head  7  includes the unit head main body  32  (corresponding to a liquid ejecting head main body in the invention) which ejects ink droplets from nozzles  44 . The unit head  7  further includes the fixation member  33  that is installed on one side surface (a surface on a side opposing the installation surfaces  25  when installed in the base plate  23 ) of the unit head main body  32 . In addition, the unit head main body  32  and the fixation member  33  are fixed to each other by using an adhesive  34  (corresponding to a position adjusting part in the invention) in a state in which a relative position between the unit head main body and the fixation member  33  is adjusted. As illustrated in  FIG. 6 , the unit head main body  32  of the present embodiment includes a pressure generation unit  37  and a channel unit  38 , and is configured to be installed in a case  43  (a sort of enclosure member of the unit head main body  32 ) in a state in which these members are stacked. 
     The case  43  forms the major part of an upper surface and a side surface of the unit head main body  32 , and is a box-shaped member, made of a resin. The side surface side of the case  43  is fixed to a fixation surface  59  of the fixation member  33 . As illustrated in  FIGS. 5A and 5B , a through-hole  54  (which has a rectangular opening elongated in the nozzle string direction) is formed in a central in a plan view of the case  43  in a state in which the opening penetrates through the case  43  in the height direction. In addition, one end of a flexible cable  56  is accommodated in the through-hole  54 . Further, ink introduction paths  55  are formed in the case  43 . Upper ends of the ink introduction paths  55  protrude upward from the upper surface of the case  43  as illustrated in  FIGS. 5A and 5B . In the present embodiment, two ink introduction paths  55  protrude so as to correspond to two nozzle strings  42 , and are connected to the ink supply tube  8 . Furthermore, channels may be provided in the base plate  23 , and the ink introduction paths  55  may be connected to the channels. Thus, in the present embodiment, the ink is introduced into the ink introduction paths  55  from the ink supply tube  8  through the channels. Moreover, lower ends of the ink introduction paths  55  are connected to a liquid supply channel  49  of the channel unit  38 . 
     As illustrated in  FIG. 6 , the channel unit  38  includes the nozzle plate  39  (a sort of nozzle formation member) in which a plurality of nozzles  44  are opened in a straight line shape (a line shape). The channel unit  38  also includes a communication substrate  40  in which the liquid supply channel  49  is defined. The plurality of lined-up nozzles  44  are provided at equal intervals from the nozzle  44  on one end side to the nozzle  44  on the other end side with pitches corresponding to a dot formation density. In the present embodiment, 360 nozzles  44  are lined up with pitches corresponding to 360 dpi, thereby forming the nozzle string  42  (a sort of nozzle group). In addition, in the present embodiment, the two nozzle strings  42  are formed in the nozzle plate  39 . Further, a lower surface of the nozzle plate  39  corresponds to the nozzle surface  45 . 
     Further, the pressure generation unit  37  is formed as a unit in which is stacked a pressure chamber formation substrate  46  (a sort of pressure chamber formation member) in which a pressure chamber  48  is formed, an elastic membrane  47 , a piezoelectric element  51 , and a protective substrate  41 . The ink is introduced into the pressure chamber  48  through the liquid supply channel  49 . Further, a driving signal from the control unit is supplied to the piezoelectric element  51  via the flexible cable  56  so as to drive the piezoelectric element  51 , thereby causing pressure variation of the pressure chamber  48 . This pressure variation is used, thereby ejecting ink droplets from the nozzles  44  via a nozzle communication path  52  of the communication substrate  40 . 
     The unit head main body  32  with this configuration is fixed to the fixation member  33  and is installed in the base plate  23  via the fixation member  33 . As illustrated in  FIGS. 7A and 7B , the fixation member  33  includes the fixation surface  59  (corresponding to a fixation part in the invention) to which the unit head main body  32  is fixed. The fixation member  33  also includes the reference surface  58  that is formed on a side opposite the fixation surface  59  and includes the reference part  60  serving as a positioning reference for an installation target (base plate  23 ) of the unit head main body  32 . 
     The fixation member  33  of the present embodiment is made of a metal (such as, for example, stainless steel) that has higher rigidity than the case  43 . The fixation member includes a plate-shaped part  61  provided with the fixation surface  59  and the reference surface  58  on its front and rear surfaces, and partition walls  62  which protrude from a surface (fixation surface  59 ) on an opposite side to the reference surface  58  of the plate-shaped part  61 . In addition, a dimension (height) of the fixation member  33  in a direction perpendicular to the nozzle surface  45  is aligned so as to be substantially the same as a dimension (height) of the case  43  in the same direction. Further, the unit head main body  32  is fixed to the fixation surface  59  of the fixation member  33  in a state in which the upper surface thereof is aligned with the upper surface of the fixation member  33  and the lower surface (nozzle surface  45 ) is aligned with the lower surface of the fixation member  33 . 
     The plate-shaped part  61  aligns a dimension (width) of the unit head  7  in the parallel arrangement direction (nozzle string direction) with a width of the storage section  24 . The plate-shaped part  61  is fitted between the two receiving surfaces  27  of the storage section  24  in a state in which the fixation member  33  is installed in the storage section  24  of the base plate  23 , thereby defining a position of the fixation member  33  (unit head  7 ) in the same direction. In addition, the upper surface of the plate-shaped part  61  is in contact with the ceiling  28  of the storage section  24  in a state in which the fixation member  33  is installed in the storage section  24  of the base plate  23 , thereby defining a position of the fixation member  33  (unit head  7 ) in the height direction. Further, in the present embodiment, a surface (a surface on an opposite side to the fixation surface  59 ) on a side opposing the storage section  24  is the flat reference surface  58  serving as a reference of a relative position of the nozzle string  42 . Furthermore, in the present embodiment, portions (that are both ends of the reference surface  58  and are in contact with the installation surface  25  of the base plate  23 ) are set as the reference part  60 . Thus, the reference surface  58  becomes an existing flat surface. The reference part  60  is in contact with the installation surface  25  in a state in which the fixation member  33  is installed in the storage section  24  of the base plate  23 , thereby defining a position of the fixation member  33  (unit head  7 ) in a thickness direction (a direction perpendicular to the nozzle string  42  in a surface parallel to the nozzle surface  45 ) of the base plate  23 . Therefore, a plurality of reference parts may be formed in a protruding manner, and a virtual plane including tops thereof may be used as a reference face. The details thereof will be described later. 
     The partition walls  62 , which protrude from the fixation surface  59  (opposite the reference surface  58 ) are provided on both sides in the width direction further inward than the ends of the plate-shaped part  61  in the width direction (nozzle string direction). A gap between the mutually opposing partition wall  62  and the partition wall  62  is slightly larger than a dimension (width) of the unit head main body  32  in the nozzle string direction. In addition, a dimension of the partition wall  62  in the thickness direction of the plate-shaped part  61  (base plate  23 ) is substantially the same as a dimension (thickness) of the unit head main body  32  in the same direction. Further, a flat surface on an opposite side to the reference surface  58  of the plate-shaped part  61  interposed between the partition wall  62  and the partition wall  62  corresponds to the fixation surface  59 . The unit head main body  32  is installed on the fixation surface  59  via the adhesive  34  (refer to  FIG. 9A ) in a state of defining a relative position with the fixation member  33  (reference surface  58 ). Furthermore, through-holes  64  corresponding to the screw holes  29  of the base plate  23  are opened in both ends located further outward than the partition walls  62  of the plate-shaped part  61 . An inner diameter of the through-hole  64  is set to be slightly larger than an inner diameter of the screw hole  29  of the base plate  23  so as to finely adjust a relative position between the base plate  23  and the fixation member  33 . Further, screws are inserted into the screw holes  29  through the through-holes  64 , and thus the fixation member  33  can be fixed to the base plate  23 . 
     Here, a relative position between the fixation member  33  (reference surface  58 ) and the unit head main body (nozzle string  42 ) is adjusted on the basis of an alignment pattern (a sort of pattern) that is formed on a landing target by ejecting ink from each nozzle  44  of the unit head main body  32 . More specifically, a linear alignment pattern is formed on a landing target by ejecting ink from the nozzle string  42  in a direction along the reference surface  58 . A relative position between the fixation member  33  and the unit head main body  32  is adjusted with high accuracy so that the alignment pattern is parallel to the reference surface  58 . In addition, a method of adjusting a relative position will be described later. Further, a relative position between the fixation member  33  (reference surface  58 ) and the unit head main body  32  (nozzle string  42 ) is adjusted, and the adhesive  34  fills a gap between the fixation surface  59  and the unit head main body  32  in a state of maintaining this adjusted posture. As above, in the present embodiment, the adhesive  34  functions as a position adjusting part for adjusting a relative position between the fixation member  33  (reference surface  58 ) and the unit head main body  32  (nozzle string  42 ). In other words, the adhesive  34  allows a gap between the fixation surface  59  and the unit head main body  32  to be adjusted, thereby maintaining a relative position between the fixation member  33  (reference surface  58 ) and the unit head main body  32  (nozzle string  42 ). As the adhesive  34 , for example, a UV adhesive, an instantaneous adhesive, or the like is used. Such an adhesive of short curing time is used to improve workability. 
     Next, a manufacturing method of the head unit  2  with the above-described configuration will be described. A manufacturing method of the head unit  2  includes a position adjusting step of adjusting a relative position between the nozzle string  42  of the unit head main body  32  and the reference surface  58  of the fixation member  33 . The manufacturing method also includes a unit head creating step of injecting the adhesive  34  between the unit head main body  32  and the fixation surface  59  in a state in which the nozzle string  42  is positioned with respect to the reference surface  58 , so as to fix the fixation member  33  to the unit head main body  32 . The manufacturing method also includes a unit head installing step of causing the reference part  60  of the fixation member  33  to be in contact with the installation surface  25  of the base plate  23  and fixing the fixation member  33  to the base plate  23  in a state of being positioned with reference to the base plate  23 . In addition, the position adjusting step includes an inspection step of forming an alignment pattern on a landing target by ejecting a liquid from each nozzle  44  of the unit head main body  32 , and an adjustment step of adjusting a relative position of the nozzle string  42  for the reference surface  58  on the basis of the alignment pattern. 
       FIGS. 8A to 9B  are schematic diagrams illustrating a manufacturing method of the head unit  2 .  FIGS. 8A to 8C  and  FIG. 9A  are plan views, and  FIG. 9B  is a bottom view. In addition, in  FIGS. 8A to 9B , a jig or the like is indicated by a broken line. Further,  FIGS. 8D and 8E  are schematic diagrams illustrating examples of an alignment pattern formed on a landing target. 
     In the position adjusting step, first, the fixation member  33  is installed in a first jig  66 . As illustrated in  FIG. 8A , the first jig  66  is a jig which holds the fixation member  33 , and has temporary installation surfaces  67  where the reference surface  58  of the fixation member  33  is installed. The temporary installation surfaces  67  are formed in the same shape as the shape of the installation surface  25  of the base plate  23 . The temporary installation surfaces  67  are provided at two locations that are in contact with the reference parts  60  of the fixation member  33  with a jig vacancy  68  interposed therebetween. In addition, the fixation member  33  is fixed to the first jig  66  via screws in a state in which the reference part  60  is in contact with and positioned with respect to the temporary installation surfaces  67 . Next, as illustrated in  FIG. 8A , the unit head main body  32  becomes close to the fixation surface  59  of the fixation member  33  by using a second jig  69 . The second jig  69  is a jig that is fixed to one surface (a surface on an opposite side to the fixation surface  59  side) of the unit head main body  32  and can advance towards and retreat from the first jig  66 . A part of the second jig  69  (to which the unit head main body  32  is installed) can be manually or automatically rotated in a surface parallel to the nozzle surface  45 . The unit head main body  32  is accommodated between the partition wall  62  and the partition wall  62  of the fixation member  33  by the second jig  69 . Thus, the side surface of the unit head main body  32  (case  43 ) and the fixation surface  59  are maintained in a parallel state. Further, the ink introduction path  55  of the case  43  is connected to the supply tube (not illustrated) which supplies ink. Thus, the ink is supplied to an internal channel of the unit head main body  32 . 
     Subsequently, in this state, the ink is simultaneously ejected downwardly (a direction along the reference surface  58 ) from all the nozzles  44  forming the nozzle strings  42  of the unit head main body  32 , so as to record a linear ruled line in the nozzle string direction on a landing target on the lower side. In the present embodiment, the unit head main body  32  has two nozzle strings  42 , and thus two ruled lines are recorded on the landing target. An image of the recorded alignment patterns is captured by a camera (not illustrated), and is displayed on a screen of a monitor (not illustrated), as illustrated in  FIG. 8D or 8E . In addition, in  FIGS. 8D and 8E , the ruled lines indicated by the broken lines A are the alignment patterns recorded by the unit head main body  32 , and the ruled lines indicated by the solid lines B are reference lines. In the present embodiment, the reference lines B are displayed on the monitor in a superimposition manner on the captured image of the alignment patterns A. In addition, the reference lines B are arranged in two lines so as to the two alignment patterns A. Further, the reference lines B are adjusted (that is, a relative position for the reference surface  58  is defined) so as to be parallel to the reference surface  58  (or the temporary installation surface  67  of the first jig  66 ) of the fixation member  33  installed in the first jig  66 . Furthermore, a deviation between the reference lines B and the recorded alignment patterns A is checked (inspected) from the monitor (inspection step). 
     In this case, for example, in a case where the recorded alignment patterns A are tilted with respect to the reference lines B as illustrated in  FIG. 8D , the position of the unit head main body  32  is adjusted so that the alignment patterns A are parallel to the reference lines B by using the second jig  69  as illustrated in  FIG. 8B . Accordingly, a relative position between the reference surface  58  and the nozzle strings  42  is indirectly adjusted. For example, a tilt angle of the alignment patterns A relative to the reference lines B is measured with a scale (not illustrated) or the like, and an angle (tilt) of the unit head main body  32  in the surface parallel to the nozzle surface  45  is adjusted on the basis of the tilt angle (adjusting step). In addition, in relation to a tilt of the alignment patterns A relative to the reference lines B, an allowable error margin of the specifications of the product (for example, a distance between the end (a pattern corresponding to the nozzle located at the end of the nozzle string  42 ) of the alignment pattern A and the reference line B is 0±10 μm) may be prescribed. The adjustment may be performed so that a tilt falls within the target margin. Further, after the position of the unit head main body  32  is adjusted, the alignment patterns A may be recorded again, and a tilt thereof relative to the reference lines B may be checked, so that a position of the unit head main body  32  is adjusted using the second jig  69  until the alignment patterns A become parallel to the reference lines B as illustrated in  FIG. 8E . As described above, the alignment patterns A are made parallel to the reference lines B, and thus the reference surface  58  can be made parallel to the alignment patterns A. 
     Next, in the unit head creating step, as illustrated in  FIG. 8C , the adhesive  34  fills a gap between the unit head main body  32  having undergone the position adjustment in the adjusting step and the fixation surface  59  of the fixation member  33 . At this time, the second jig  69  holds the position of the unit head main body  32  until the adhesive  34  is cured. In addition, as illustrated in  FIG. 9A , the fixation member  33  is detached from the first jig  66  after the adhesive  34  is cured, and thus the unit head  7  is completed in which a relative position between the fixation member  33  (reference surface  58 ) and the unit head main body (nozzle string  42 ) is defined. Further, in the unit head  7  created in this way, the adhesive  34  functions as a position adjusting part which adjusts a relative position between the fixation member  33  and the unit head main body  32 . In other words, as a result of adjusting a relative position between the fixation member  33  and the unit head main body  32 , as illustrated in  FIG. 9A , a gap between the fixation surface  59  of the fixation member  33  and the unit head main body  32  may be defined, but the gap is filled with (disposed in) the adhesive  34 , and thus it is possible to maintain a relative position between the fixation member  33  and the unit head main body  32 . Furthermore, a spacer made of a resin or the like may be separately used as the position adjusting part disposed in this gap, in addition to the adhesive  34 . 
     Next, in the unit head installation step, as illustrated in  FIG. 9B , the unit heads  7  manufactured in the above-described steps are sequentially fixed to the storage sections  24  of the base plate  23 . At this time, the fixation member  33  (unit head  7 ) is fitted between the receiving surfaces  27  of both sides of the base plate  23 , thereby defining a position of the unit head  7  in the parallel arrangement direction of the unit heads  7 . In addition, the upper surface of the fixation member  33  is brought into contact with the ceiling  28 , thereby defining a position of the unit head  7  in the height direction. Further, the reference part  60  of the fixation member  33  is brought into contact with the installation surface  25 , thereby defining a position of the unit head  7  in the thickness direction of the base plate  23 . In a state in which the positions of the unit head  7  are defined as described above, screws are inserted into the screw holes  29  through the through-holes  64  so as to fix the unit head  7  to the base plate  23 . Furthermore, a necessary number of unit heads  7  are fixed to the base plate  23 , thereby completing the head unit  2 . Moreover, a pin may be provided to protrude from one of the upper surface of the fixation member and the ceiling of the storage section of the base plate toward the other thereof. A pin hole into which the pin can be inserted may be opened at the other part corresponding to the pin, so that the fixation member may be fixed to the base plate in a state in which the pin is inserted into the pin hole. 
     As described above, the fixation member  33  includes the fixation surface  59  to which the unit head main body  32  is fixed. The fixation member  33  also includes the reference surface  58  that is formed on a side opposite the fixation surface  59  and includes the reference part  60  serving as a positioning reference for an installation target of the unit head main body  32 . The fixation member  33  also includes the adhesive  34  for adjusting (controlling) a relative position between the reference surface  58  and the nozzle strings  42  and is provided between the unit head main body  32  and the fixation surface  59 . Therefore, it is possible to create the unit head  7  in which a relative position between the reference surface  58  and the unit head main body  32  is adjusted (defined) in advance. For this reason, when the unit head  7  is fixed to the base plate  23 , a relative position of the reference surface  58  for the base plate  23  is precisely defined. Thus, it is possible to define a relative position of the unit head main body  32  with high accuracy. As a result, the effort to check a positional deviation of the unit head main body  32  fixed to the base plate  23  is not necessary, and thus it is possible to improve workability when installing the unit head  7  in the base plate  23 . 
     In addition, a relative position of the nozzle strings  42  and the reference surface  58  is adjusted on the basis of the alignment patterns A formed on the landing target by ejecting the ink from each nozzle  44  of the unit head main body  32 . Therefore, it is possible to adjust a position of the unit head main body  32  in consideration of ink ejecting characteristics (for example, the skew of ink droplets during flight or the like) of the unit head main body  32 . For this reason, it is possible to define a relative position of the unit head main body  32  for the base plate  23  with higher accuracy. Further, a relative position of the nozzle strings  42  is adjusted so that the linear alignment patterns A (formed on the landing target by ejecting the ink from the nozzle strings  42  in the direction along the reference surface  58 ) is parallel to the reference surface  58 . Therefore, it becomes easier to adjust a relative position between the reference surface  58  and the nozzle strings  42 . Furthermore, the term “parallel” mentioned here includes a case of being slightly shifted from a parallel state within an allowable error margin of the specifications of the product. Moreover, the installation surface  25  is in contact with the reference part  60 , and thus positions of the base plate  23  and the fixation member  33  are determined. Accordingly, it is possible to easily define a relative position of the unit head main body  32  and the base plate  23 . As a result, it is possible to further improve accuracy when installing the unit head in the base plate  23 . 
     However, a configuration of the reference part  60  of the fixation member  33  is not limited to the above-described embodiment, and a configuration may be employed in which the reference part protrude on a side opposite the fixation surface. For example, in another embodiment illustrated in  FIG. 10 , protrusions  71  which protrude toward the base plate  23  side are provided at positions opposing the installation surface  25  of a fixation member  33 ′ in the height direction of the fixation member  33 ′. The protrusions  71  are provided at both ends of a plate-shaped part  61 ′ in the width direction, and front end surfaces of both the protrusions  71  are reference parts  60 ′ that are in contact with the installation surface  25 . In addition, in this case, a virtual plane (the dot chain line in  FIG. 10 ) including the front end surfaces of both the protrusions  71  is a reference surface  58 ′. In other words, a surface of the plate-shaped part  61 ′ opposing the vacancy  26  is in a state of being depressed further toward the fixation surface  59 ′ side than the reference surface  58 ′. In this way, the vacancy  26  of the base plate  23  is not necessary that is provided so that parts other than the fixation member  33 ′ are not brought into contact with other parts of the base plate  23  in a state in which the reference part  60 ′ of the fixation member  33 ′ is brought into contact with the installation surface  25  of the base plate  23 . Accordingly, it is possible to further increase a thickness of the base plate  23  and to thus increase the strength of the base plate  23 . In addition, if an area of the front end surfaces of the protrusions  71  is made as small as possible, plane processing of the front ends requiring high flatness becomes easier. Further, other configurations are the same as those in the above-described embodiment, and thus description thereof will not be repeated. 
     A configuration may be employed in which the reference part of the fixation member is depressed from the plate-shaped part (a surface on the base plate side) to the fixation surface side (a side opposite the installation surface). In other words, the part of the fixation member opposing the vacancy is disposed further toward the base plate side than the reference part. For example, in a thickness direction (a thickness direction of the base plate, or a direction perpendicular to the installation surface) of the unit head (fixation member), a plate-shaped (flange-shaped) fixation part may extend outwardly from the middle (for example, a central portion) of the partition wall (fixation member), and a surface on an installation surface side of the fixation part may be used as a reference part. In this case, a virtual plane including the reference part that is a reference surface is disposed in the middle of the unit head (fixation member) in the thickness direction. With this configuration, when the unit head is installed in the storage section of the base plate, a part of the unit head is disposed further inward than the reference surface. In other words, a part of the unit head is stored in the vacant part of the storage section. In this way, it is possible to reduce a gap between the unit heads disposed on both sides with the base plate interposed therebetween. In addition, it is desirable to set a depth of the vacancy in consideration of a manufacturing tolerance so that a part of the unit head stored in the vacancy of the storage section is not in contact with the inner wall surface inside the vacancy. 
     In addition, in the above-described embodiment, a total of eight unit heads  7  are installed in both sides of the base plate  23 , but the invention is not limited thereto. In other words, at least one unit head may be installed in the base plate. In addition, the two nozzle strings  42  are provided on the nozzle surface  45  of the unit head main body  32 , but the invention is not limited thereto. For example, one nozzle string or three or more nozzle strings may be provided on the nozzle surface. Further, in the above-described embodiment, the alignment patterns A are adjusted so as to be parallel to the reference lines B that are adjusted so as to be parallel to the reference surface  58 , but the invention is not limited thereto. For example, the alignment patterns are adjusted so as to be parallel to reference lines that are tilted with respect to a reference surface, and thus it is possible to adjust the nozzle string so as to be tilted with respect to the reference surface. In this way, the nozzle string is tilted with respect to a paper surface direction of recording paper, and thus it is possible to reduce a nozzle pitch in the same direction and to therefore increase a resolution. 
     In addition, in the above-described embodiment, the ink is ejected from the unit head main body  32  so as to record the alignment patterns on the landing target, and a relative position between the reference surface  58  and the nozzle string  42  is indirectly adjusted by adjusting a relative position between the alignment patterns and the reference lines. However, the invention is not limited thereto. For example, the alignment patterns may not be recorded, and a relative position between the reference surface and the nozzle strings may be adjusted using the actual nozzle strings formed on the nozzle surface. For example, a glass mask on which reference lines whose relative position with a reference surface has been adjusted (defined) are drawn may be brought into contact with the nozzle surface, and a relative position between the reference lines and the nozzle strings may be adjusted so that the reference lines and the nozzle strings are parallel to each other, while checking the relative position. Further, in the above-described embodiment, a so-called bending vibration type piezoelectric element  51  has been exemplified as pressure generation means, but the invention is not limited thereto, and, for example, a so-called longitudinal vibration type piezoelectric element or a heater element may be used. 
     In the above-described embodiment, the ink jet recording head mounted in an ink jet printer has been exemplified, but the invention is applicable to heads that eject liquids other than ink. For example, the invention is applicable to a color material ejecting head that is used to manufacture color filters for a liquid crystal display or the like, an electrode material ejecting head that is used to form electrodes of an organic electroluminescence (EL) display or a field emission display (FED), a living organic matter ejecting head that is used to manufacture a biochip (biotip), and the like. 
     The entire disclosure of Japanese Patent Application No: 2013-063724, filed Mar. 26, 2013 is expressly incorporated by reference herein in its entirety.