Patent Publication Number: US-2022219469-A1

Title: Liquid Ejecting Apparatus And Method Of Fixing Liquid Ejecting Head

Description:
The present application is based on, and claims priority from JP Application Serial Number 2021-003211, filed Jan. 13, 2021, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a liquid ejecting apparatus and a method of fixing a liquid ejecting head. 
     2. Related Art 
     There has been known a liquid ejecting apparatus as represented by an ink jet printer, which ejects a liquid such as an ink. 
     A liquid ejecting apparatus described in JP-A-2018-149684 includes head bodies that eject inks and a unit base that holds the head bodies. Each head body is fixed to the unit base through a spacer by using screw members. 
     However, the method of fixing the head body to the unit base by using the screw members has a problem that it is not easy to attach and replace the head body. To deal with this, there has been a demand for a liquid ejecting apparatus that enables easy fixation of a head body to a unit base. 
     SUMMARY 
     A liquid ejecting apparatus according to an aspect of the present disclosure includes a liquid ejecting head that ejects a liquid, a holding member that holds the liquid ejecting head, a fixing member including a head portion, an engaging portion, and a shaft portion that couples the head portion to the engaging portion, and an elastic member including a first opening into which the shaft portion is inserted. One of the liquid ejecting head and the holding member includes a second opening into which the shaft portion is inserted, and the other one of the liquid ejecting head and the holding member includes a first engaged portion to be engaged with the engaging portion. The liquid ejecting head is fixed to the holding member by the engaging portion being brought into engagement with the first engaged portion such that the first opening and the second opening are disposed between the head portion and the engaging portion. 
     A method of fixing a liquid ejecting head according to an aspect of the present disclosure provides a method of fixing a liquid ejecting head including, fixing a liquid ejecting head to a holding member by using a fixing member including a head portion, an engaging portion, and a shaft portion that couples the head portion to the engaging portion, and an elastic member including a first opening into which the shaft portion is inserted, the elastic member being brought into contact with the head portion. One of the liquid ejecting head and the holding member includes a second opening into which the shaft portion is inserted, and another one of the liquid ejecting head and the holding member includes a first engaged portion to be engaged with the engaging portion. The liquid ejecting head is fixed to the holding member by the engaging portion being brought into engagement with the first engaged portion such that the first opening and the second opening are disposed between the head portion and the engaging portion while the elastic member is pressed with the head portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram illustrating a configuration example of a liquid ejecting apparatus according to a first embodiment. 
         FIG. 2  is a plan view of a head unit in  FIG. 1 . 
         FIG. 3  is a partially enlarged view of the head unit in  FIG. 2 . 
         FIG. 4  is a view corresponding to a cross-section taken along the IV-IV line in  FIG. 3 . 
         FIG. 5  is an exploded perspective view of  FIG. 4 . 
         FIG. 6  is an exploded perspective view of a liquid ejecting head illustrated in  FIG. 4 . 
         FIG. 7  is an enlarged diagram of a fixing member, an elastic member, the liquid ejecting head, and a holding member illustrated in  FIG. 5 . 
         FIG. 8  is an exploded perspective view of the fixing member, the elastic member, the liquid ejecting head, and the holding member illustrated in  FIG. 5 . 
         FIG. 9  is a cross-sectional view of the fixing member, the elastic member, the liquid ejecting head, and the holding member illustrated in  FIG. 5 . 
         FIG. 10  is a cross-sectional view of the fixing member illustrated in  FIG. 7 . 
         FIG. 11  is a plan view of the elastic member illustrated in  FIG. 7 . 
         FIG. 12  is a plan view of a first flange portion included in a holder illustrated in  FIG. 7 . 
         FIG. 13  is a perspective view of an engaged member illustrated in  FIG. 7 . 
         FIG. 14  is a cross-sectional view of the engaged member illustrated in  FIG. 7 . 
         FIG. 15  is a plan view of the engaged member illustrated in  FIG. 7 . 
         FIG. 16  is a diagram for explaining fixation of the elastic member to the liquid ejecting head. 
         FIG. 17  is another diagram for explaining fixation of the elastic member to the liquid ejecting head. 
         FIG. 18  is a diagram for explaining fixation of the liquid ejecting head to the holding member. 
         FIG. 19  is another diagram for explaining fixation of the liquid ejecting head to the holding member. 
         FIG. 20  is still another diagram for explaining fixation of the liquid ejecting head to the holding member. 
         FIG. 21  is a perspective view illustrating a fixing member of a second embodiment. 
         FIG. 22  is a cross-sectional view illustrating a fixing member of a third embodiment. 
         FIG. 23  is a cross-sectional view illustrating the fixing member of the third embodiment in an exploded state. 
         FIG. 24  is a diagram schematically illustrating a liquid ejecting head and a holding member of a first modified example. 
         FIG. 25  is a diagram illustrating a layout of the liquid ejecting head and the holding member of the first embodiment. 
         FIG. 26  is a diagram schematically illustrating a layout of a liquid ejecting head and a holding member of a second modified example. 
         FIG. 27  is a diagram schematically illustrating a liquid ejecting head and a holding member of a third modified example. 
         FIG. 28  is a diagram schematically illustrating a liquid ejecting head and a holding member of a fourth modified example. 
         FIG. 29  is a diagram schematically illustrating a holding member of a fifth modified example. 
         FIG. 30  is a diagram schematically illustrating a fixing member and a liquid ejecting head of a sixth modified example. 
         FIG. 31  is a plan view of the fixing member and a first flange portion of the liquid ejecting head illustrated in  FIG. 30 . 
         FIG. 32  is a diagram schematically illustrating an elastic member of a seventh modified example. 
         FIG. 33  is a diagram schematically illustrating an elastic member of an eighth modified example. 
         FIG. 34  is a diagram schematically illustrating a fixing member of a ninth modified example. 
         FIG. 35  is a schematic diagram illustrating a liquid ejecting apparatus of a tenth modified example. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Modes for carrying out the present disclosure will be described below with reference to the drawings. It is to be noted, however, that dimensions and scales of constituents in the drawings may be different from reality as appropriate. Moreover, the following embodiments represent preferred specific examples of the present disclosure and are therefore provided with various restrictions which are deemed to be favorable from technical perspectives. However, the scope of the present disclosure is not limited to these embodiments unless there is a specific statement to restrict the scope of the present disclosure in the following description. 
     The following description will be given by appropriately using the x axis, the y axis, and the z axis which are orthogonal to one another. Meanwhile, one direction along the x axis will be referred to as x1 direction while a direction opposite to the x1 direction will be referred to as x2 direction. Likewise, one direction along the y axis will be referred to as y1 direction while a direction opposite to the y1 direction will be referred to as y2 direction. Moreover, one direction along the z axis will be referred to as z1 direction while a direction opposite to the z1 direction will be referred to as z2 direction. In the meantime, view in the z1 direction or the z2 direction will be referred to as “plan view”. Meanwhile, view of a section taken along a plane including the z axis in a direction orthogonal to the z axis will be referred to as “cross-sectional view”. In the meantime, the direction along the z axis corresponds to a gravitational direction. The z1 direction corresponds to “downward in the gravitational direction” while the z2 direction corresponds to “upward in the gravitational direction”. 
     1. FIRST EMBODIMENT 
     1-1. Overall Configuration of Liquid Ejecting Apparatus  100   
       FIG. 1  is a schematic diagram illustrating a configuration example of a liquid ejecting apparatus  100  according to a first embodiment. The liquid ejecting apparatus  100  illustrated in  FIG. 1  is a printing apparatus of an ink jet type which ejects an ink as an example of a “liquid” onto a medium PP in the form of droplets. The liquid ejecting apparatus  100  of this embodiment is a printing apparatus of so-called a line type which distributes multiple nozzles for ejecting the ink across an entire range in a width direction of the medium PP. Though the medium PP is typically print paper, a print target of an arbitrary material such as a resin film and a cloth is also used as the medium PP. 
     The liquid ejecting apparatus  100  illustrated in  FIG. 1  includes a circulation mechanism  92 , a control unit  93 , a medium transportation mechanism  94 , and a head unit  10 . The head unit  10  includes liquid ejecting heads  1 . Moreover, a liquid container  91  is installed in the liquid ejecting apparatus  100 . 
     The liquid container  91  is a liquid storage unit that stores the ink. For example, a cartridge that is attachable to and detachable from the liquid ejecting apparatus  100 , an ink package having a bag shape formed from a flexible film, or an ink-refillable ink tank is used for the liquid container  91 . Any type of the ink may be stored in the liquid container  91 . For example, the liquid container  91  includes multiple sub-containers for storing inks of types different from one another. 
     The circulation mechanism  92  supplies the ink stored in the liquid container  91  to the liquid ejecting head  1 . To be more precise, the circulation mechanism  92  supplies the ink stored in the liquid container  91  to the liquid ejecting head  1 , and collects the ink discharged from the liquid ejecting head  1  and returns the ink to the liquid ejecting head  1  again. For example, the circulation mechanism  92  includes a flow channel for supplying the ink to the liquid ejecting head  1 , a flow channel for collecting the ink discharged from the liquid ejecting head  1 , a sub-tank for storing the collected ink, a pump for transferring the ink, and the like. 
     The control unit  93  is a control device that controls operations of respective elements included in the liquid ejecting apparatus  100 . The control unit  93  includes a processing circuit such as a central processing unit (CPU) and a field programmable gate array (FPGA), and a storage circuit such as a semiconductor memory. Various programs and various data are stored in the storage circuit. The processing circuit achieves a variety of control by executing the programs and using the data as appropriate. 
     The medium transportation mechanism  94  transports the medium PP in a direction of transportation DM by being controlled by the control unit  93 . Here, the direction of transportation DM is the y1 direction, for example. The direction of transportation DM is not limited only to the y1 direction, but may also be other directions. The medium transportation mechanism  94  includes a transportation roller that is elongate along the x axis, and a motor that rotates the transportation roller. Note that the medium transportation mechanism  94  is not limited only to the configuration to use the transportation roller. For example, the medium transportation mechanism  94  may be configured to use a drum that transports the medium PP in a state of being stuck to an outer peripheral surface by use of static electricity or the like, or configured to use an endless belt. 
     The head unit  10  is a line head in which the liquid ejecting heads  1  are arranged along the x axis. The liquid ejecting heads  1  eject the ink from the respective nozzles to the medium PP under the control of the control unit  93 . An image is formed on a surface of the medium PP by ejecting the ink onto the medium PP from the respective liquid ejecting heads  1  in parallel with the transportation of the medium PP by the medium transportation mechanism  94 . 
     1-2. Head Unit  10   
       FIG. 2  is a plan view of the head unit  10  in  FIG. 1 .  FIG. 3  is a partially enlarged view of the head unit  10  in  FIG. 2 .  FIG. 4  corresponds to a cross-section taken along the IV-IV line in  FIG. 3 .  FIG. 5  is an exploded perspective view of  FIG. 4 . 
     In addition to the liquid ejecting heads  1 , the head unit  10  includes a holding member  2 , fixing members  3 , and elastic members  4  as illustrated in  FIGS. 2 to 5 . 
     1-2a. Holding Member  2   
     The holding member  2  illustrated in  FIG. 2  is a carriage that holds the liquid ejecting heads  1 . A body portion  21  is an elongate member that extends in the x1 direction. The material of the body portion  21  is a metal such as aluminum and stainless steel, or a resin. When the head unit  10  is formed into the line head that is elongate in the x1 direction as discussed in this embodiment, a highly rigid metal material may be used for the body portion  21  so as to avoid deformation even when holding two or more liquid ejecting heads  1 . 
     The holding member  2  includes the body portion  21  and engaged members  25 . The body portion  21  includes openings H 2 . Each opening H 2  is a wall portion that forms a hole to penetrate the holding member  2 . The openings H 2  are provided one by one to the liquid ejecting heads  1 . The liquid ejecting heads  1  are held by the holding member  2  in the state of being inserted into the respective openings H 2 . In  FIG. 2 , illustration of part of the liquid ejecting heads  1  is omitted in order to facilitate the understanding of the openings H 2 . 
     In the example illustrated in  FIG. 2 , the openings H 2  are divided into a first row L 2   a  and a second row L 2   b , and the openings H 2  in each row are arranged in the x1 direction. Here, the shape of the holding member  2  is such a shape that is symmetric with respect to the center of the holding member  2  in plan view. Meanwhile, although illustration is omitted, when a surface of a transportation drum for transporting the medium PP has a curved shape, a surface of the holding member  2  opposed to the surface of the transportation drum is slightly inclined so as to trace this surface relative to a plane that has a virtual line extending along the gravitational direction as a normal line, or in other words, a horizontal plane. Likewise, an ejecting surface S 11  of each liquid ejecting head  1  to be described later is slightly inclined relative to the plane that has the virtual line extending along the gravitational direction as the normal line, or in other words, the horizontal plane. 
     As illustrated in  FIGS. 3 and 5 , the body portion  21  is provided with positioning pins  211 . Two positioning pins  211  are provided to each liquid ejecting head  1 . As illustrated in  FIG. 5 , the positioning pins  211  project in the z2 direction from the body portion  21 . The positioning pins  211  are used for positioning the liquid ejecting heads  1  relative to the holding member  2 . As illustrated in  FIG. 2 , the positioning pins  211  are provided corresponding to the after-mentioned positioning holes  1521  included in the liquid ejecting head  1 . Here, such positioning holes may be provided to the body portion  21  of the holding member  2  and the corresponding positioning pins may be provided to the liquid ejecting heads  1  instead. 
     As illustrated in  FIG. 5 , the body portion  21  includes a recess  210 . The engaged member  25  is disposed in the recess  210 . The engaged member  25  is used for fixing the liquid ejecting head  1  to the holding member  2 . The engaged member  25  will be described later in detail. 
     1-2b. Elastic Members  4   
     As illustrated in  FIG. 2 , two elastic members  4  are provided to each of the liquid ejecting heads  1 . Each elastic member  4  is an elastic plate spring, for example. The elastic members  4  are used for fixing the liquid ejecting heads  1  to the holding member  2 . Although the material of the elastic members  4  is not limited to a particular material, the elastic members  4  are made of a metal such as stainless steel and a nickel alloy, for example. Meanwhile, as illustrated in  FIGS. 4 and 5 , the holding member  2  is not disposed sideways of the elastic members  4 , or in other words, at a position in the y1 direction relative to the elastic members  4 . The holding member  2  is located at a position in the z2 direction relative to the elastic members  4 . The elastic members  4  will be described later in detail. 
     1-2c. Fixing Members  3   
     The fixing members  3  illustrated in  FIGS. 2 to 5  are used for fixing the liquid ejecting heads  1  to the holding member  2 . The use of the fixing members  3  makes it possible to fix the liquid ejecting heads  1  to the holding member  2  easily without using any screws as in the related art. The fixing members  3  will be described later in detail. 
     1-2d. Liquid Ejecting Head  1   
     As illustrated in  FIGS. 3 to 5 , the liquid ejecting head  1  has the ejecting surface S 11  provided with the nozzles for ejecting the ink. As illustrated in  FIG. 4 , the liquid ejecting head  1  is held by the holding member  2  such that the ejecting surface S 11  is located in the front line in the z1 direction among the constituents of the head unit  10 . 
       FIG. 6  is an exploded perspective view of the liquid ejecting head  1  illustrated in  FIG. 4 . As illustrated in  FIG. 6 , the liquid ejecting head  1  includes an electric coupling portion  11 , a flow channel structure  12 , a wiring substrate  13 , head chips  50 , a fixation plate  14 , and a holder  15 . These elements are stacked on one another and fastened together with screws  19 . 
     As illustrated in  FIG. 6 , the electric coupling portion  11  includes a relay substrate  111 , two connectors  112 , and two covers  113 . The relay substrate  111  is electrically coupled to the head chips  50  through the wiring substrate  13 . The relay substrate  111  is provided with coupling terminals and various wires. The relay substrate  111  is a rigid substrate, for example. The relay substrate  111  is disposed on the wiring substrate  13  such that its plate surface extends in the z1 direction. 
     Meanwhile, the connectors  112  are coupled to the relay substrate  111 . The connectors  112  are used for establishing electric coupling to the outside of the liquid ejecting head  1 . Meanwhile, the relay substrate  111  is sandwiched between the two covers  113  and protected by the two covers  113 . One of the two covers  113  covers a surface in the y1 direction of the relay substrate  111  while the other cover  113  covers a surface in the y2 direction of the relay substrate  111 . 
     The flow channel structure  12  is disposed at a position in the z1 direction relative to the electric coupling portion  11 . The flow channel structure  12  includes flow channel substrates  121 ,  122 ,  125 ,  126 , and  127 . The flow channel substrates  121 ,  122 ,  125 ,  126 , and  127  are arranged in this order in the z2 direction. 
     The flow channel substrate  127  is provided with flow channel pipes  129  that project in the z2 direction. The flow channel pipes  129  are used for coupling with not-illustrated tubes and the like to be coupled to the circulation mechanism  92  illustrated in  FIG. 1 . Through holes and recesses are formed in the flow channel substrates  121 ,  122 ,  125 , and  126 . Flow channels S 12  in which the ink flows are formed from the through holes and the recesses. The flow channels S 12  include flow channels that supply the ink from the circulation mechanism  92  illustrated in  FIG. 1  to the head chips  50  illustrated in  FIG. 6 , and flow channels that return the ink discharged from the head chips  50  to the circulation mechanism  92 . 
     Here, the number of the flow channel substrates included in the flow channel structure  12  is not limited to 5. The number of the flow channel substrates may be in a range from 1 to 4 or equal to or above 6. Meanwhile, the material of each of the flow channel substrates  121 ,  122 ,  125 ,  126 , and  127  is one of a metal such as stainless steel (SUS) and aluminum, a ceramic, and a resin such as poly(p-phenylene benzobisoxazole) and polypropylene. 
     The wiring substrate  13  is disposed between the components of the flow channel structure  12 . In the example illustrated in  FIG. 6 , the wiring substrate  13  is disposed between the flow channel substrate  122  and the flow channel substrate  125 . The wiring substrate  13  is a mounted component for electrically coupling the relay substrate  111  to the head chips  50 . The wiring substrate  13  is a rigid substrate, for example. Meanwhile, the wiring substrate  13  is provided with connector  131  which serves as a coupling component to be coupled to the relay substrate  111 . 
     The head chips  50  are disposed at positions in the z1 direction relative to the flow channel structure  12 . Each head chip  50  includes nozzles. Moreover, each head chip  50  includes a mechanism for ejecting the ink from the nozzles. Specifically, each head chip  50  includes an actuator unit  51  and a wiring member  52 . 
     The actuator unit  51  includes a nozzle plate provided with the nozzle, a flow channel member includes a flow channel that communicates with the nozzle, a pressure chamber substrate includes a pressure chamber that communicates with the flow channel, a vibration plate for changing a pressure inside the pressure chamber, and a piezoelectric element that vibrates the vibration plate. Meanwhile, the piezoelectric element includes a piezoelectric body and an electrode. The electrode is electrically coupled to the wiring member  52 . In the meantime, the actuator unit  51  forms part of the ejecting surface S 11  provided with the nozzle. 
     The wiring member  52  includes a driving circuit for driving the piezoelectric element included in the actuator unit  51 . The wiring member  52  is a chip on film (COF), for example. The wiring member  52  electrically couples the piezoelectric element included in the actuator unit  51  to the wiring substrate  13 . The piezoelectric element included in the actuator unit  51  is driven in response to a driving signal from the control unit  93  illustrated in  FIG. 1 . 
     As illustrated in  FIG. 6 , the fixation plate  14  is a plate-like member for fixing the head chips  50  to the holder  15 . The fixation plate  14  includes openings for exposing the nozzles included in the head chips  50 . A surface in the z1 direction of the fixation plate  14  forms a bottom surface of the liquid ejecting head  1 . The bottom surface forms part of the ejecting surface S 11 . The ejecting surface S 11  is formed from the bottom surface of the fixation plate  14  and a bottom surface of the actuator unit  51 . The material of the fixation plate  14  is a metal such as stainless steel. 
     The holder  15  is disposed at a position in the z1 direction relative to the flow channel structure  12 . The holder  15  has a prescribed thickness in the z1 direction. The holder  15  holds the fixation plate  14  and the head chips  50 . The material of the holder  15  is stainless steel, for example. Instead, the material of the holder  15  may be any of a metal other than the stainless steel, a resin, and the like. 
     The holder  15  includes a base portion  151 , a first flange portion  152   a , and a second flange portion  152   b . The base portion  151  is a plate-like portion extending along x-y plane. The base portion  151  includes recesses for housing the head chips  50 . Moreover, the base portion  151  includes through holes that continue from the recesses and penetrate the base portion  151  in the z1 direction. The wiring member  52  is inserted into each through hole. 
     The first flange portion  152   a  is a portion that bulges in the y1 direction from the base portion  151 . The second flange portion  152   b  is a portion that bulges in the y2 direction from the base portion  151 . The first flange portion  152   a  and the second flange portion  152   b  have an elongate shape of which longitudinal direction is in line with the x1 direction. The first flange portion  152   a  and the second flange portion  152   b  are used for fixing the liquid ejecting head  1  to the above-mentioned holding member  2 . 
     Meanwhile, as illustrated in  FIG. 5 , the first flange portion  152   a  includes an opening  101  having a second opening  102 , and a pair of fixation holes  1522 . Details of the second opening  102  will be described later. The opening  101  is disposed between the pair of fixation holes  1522  in the x1 direction. 
     Meanwhile, as illustrated in  FIG. 6 , the second flange portion  152   b  includes an opening  101  having a second opening  102 , a pair of positioning holes  1521 , and a pair of fixation holes  1522 . Then opening  101  is disposed between the pair of fixation holes  1522  in the x1 direction. Meanwhile, the pair of fixation holes  1522  are disposed between the pair of positioning pins  211  in the x1 direction. The positioning holes  1521  are provided corresponding to the positioning pins  211  illustrated in  FIG. 3 . The positioning pins  211  are inserted into the respective positioning holes  1521 . Insertion of the positioning pins  211  into the positioning holes  1521  makes it possible to position the liquid ejecting head  1  relative to the holding member  2  before the liquid ejecting head  1  is fixed to the holding member  2 . 
     This embodiment does not adopt a fastening method by using screws provided with spiral threads for fixation of the liquid ejecting head  1  to the holding member  2 . Accordingly, the fixation holes  1522  are not used in this embodiment. However, by providing the liquid ejecting head  1  with the fixation holes  1522  that allow insertion of the screws as described above, it is possible to apply a fixation method using screw fastening to a holding member that includes threaded grooves unlike the holding member in this embodiment. 
     1.3. Configuration Concerning Fixation of Liquid Ejecting Head  1  to Holding Member  2   
       FIG. 7  is an enlarged diagram of the fixing member  3 , the elastic member  4 , the liquid ejecting head  1 , and the holding member  2  illustrated in  FIG. 5 .  FIG. 8  is an exploded perspective view of the fixing member  3 , the elastic member  4 , the liquid ejecting head  1 , and the holding member  2  illustrated in  FIG. 5 .  FIG. 9  is a cross-sectional view of the fixing member  3 , the elastic member  4 , the liquid ejecting head  1 , and the holding member  2  illustrated in  FIG. 5 . Note that illustration of the fixation holes  1522  will be omitted in  FIGS. 7 to 9  as appropriate. 
     As illustrated in  FIGS. 7 to 9 , the elastic member  4 , the liquid ejecting head  1 , and the holding member  2  are arranged in this order in the z1 direction. The liquid ejecting head  1  is fixed to the holding member  2  by using the fixing member  3 . Specifically, the first flange portion  152   a  and the second flange portion  152   b  of the holder  15  included in the liquid ejecting head  1  are fixed to the engaged member  25  included in the holding member  2 . A description will be given below of the fixing member  3  concerning the fixation of the liquid ejecting head  1  to the holding member  2 , the elastic member  4 , the liquid ejecting head  1 , and the holding member  2  by using the after-mentioned  FIGS. 10 to 20  with reference to  FIGS. 7 to 9 . Note that the first flange portion  152   a  and the second flange portion  152   b  have the same configuration. Accordingly, details concerning the first flange portion  152   a  will be representatively described below and a description of details concerning the second flange portion  152   b  will be omitted as appropriate. 
       FIG. 10  is a cross-sectional view of the fixing member  3  illustrated in  FIG. 7 . The fixing member  3  illustrated in  FIG. 10  is used for fixing the liquid ejecting head  1  to the engaged member  25  of the holding member  2 . The material of the fixing member  3  is a metal such as aluminum and stainless steel. 
     As illustrated in  FIG. 10 , the fixing member  3  includes a head portion  31 , an engaging portion  32 , and a shaft portion  33 . The shaft portion  33  couples the head portion  31  to the engaging portion  32 . 
     In the example illustrated in  FIGS. 7 and 8 , the shape of the head portion  31  is substantially a columnar shape. Instead, the head portion  31  may take on a prismatic shape, for example. The shaft portion  33  is an elongate portion. Meanwhile, the engaging portion  32  is another elongate portion. Here, a length in a longitudinal direction of the engaging portion  32  is smaller than a length in a longitudinal direction of the shaft portion  33 . Moreover, the longitudinal direction of the shaft portion  33  intersects with the longitudinal direction of the engaging portion  32 . In the example illustrated in  FIGS. 7 and 8 , the longitudinal direction of the shaft portion  33  is orthogonal to the longitudinal direction of the engaging portion  32 . 
     The head portion  31  is a portion that comes into contact with the elastic member  4 . In this embodiment, the head portion  31  functions as an operating portion for performing a rotating operation of the fixing member  3  in the x-y plane with respect to the liquid ejecting head  1  when fixing the liquid ejecting head  1 . Meanwhile, engaging portion  32  is a portion to engage with the holding member  2 . In this embodiment, the engaging portion  32  is formed to be fittable into the first flange portion  152   a  and the engaged member  25 , respectively. In a state where the first flange portion  152   a  is fixed to the engaged member  25  as illustrated in  FIG. 7 , the engaging portion  32  is fitted into the engaged member  25 . To be more precise, the fixing member  3  is fitted into the engaged member  25  in a state where the elastic member  4  and the first flange portion  152   a  are located between the head portion  31  and the engaging portion  32 . Meanwhile, the shaft portion  33  has a length that corresponds to a length in the z1 direction of the elastic member  4  and the first flange portion  152   a.    
       FIG. 11  is a plan view of the elastic member  4  illustrated in  FIG. 7 . The elastic member  4  illustrated in  FIG. 11  is a spring member having elasticity. By providing the elastic member  4 , it is possible to increase fixation stability when fixing the liquid ejecting head  1  to the holding member  2  or when using the liquid ejecting apparatus  100  as compared to a case without providing the elastic member  4 . 
     As illustrated in  FIGS. 7 to 9, and 11 , the elastic member  4  is a plate spring having an elongated flat plate shape, and the elastic member  4  is partially bent. The elastic member  4  comes into contact with the head portion  31  of the fixing member  3  in a state where the liquid ejecting head  1  is fixed to the holding member  2  by using the fixing member  3 . 
     The elastic member  4  has elasticity. The elastic member  4  includes a base portion  41  and two spring portions  42 . The base portion  41  is a portion located between the two spring portions  42 . The spring portions  42  are elastically deformable along the z axis. 
     Meanwhile, the base portion  41  includes a first opening  401  into which the shaft portion  33  is inserted. The first opening  401  is a wall portion that forms a hole to penetrate the base portion  41  of the elastic member  4 . As illustrated in  FIG. 11 , a shape in plan view of the hole defined by the first opening  401  is a shape in conformity to a longitudinal direction of the elastic member  4 . The hole defined by the first opening  401  corresponds to the shaft portion  33  and the engaging portion  32  of the fixing member  3 , and is formed such that the shaft portion  33  and the engaging portion  32  can be inserted into the hole. Meanwhile, as illustrated in  FIGS. 7 and 8 , a shape in plan view of the elastic member  4  corresponds to a shape in plan view of the first flange portion  152   a . A length in the longitudinal direction of the elastic member  4  is equal to or below a length in a longitudinal direction of the first flange portion  152   a.    
       FIG. 12  is a plan view of the first flange portion  152   a  included in the holder  15  illustrated in  FIG. 7 . The first flange portion  152   a  illustrated in  FIG. 12  is used for fixing the holder  15  of the liquid ejecting head  1  to the engaged member  25 . 
     As illustrated in  FIGS. 7 and 12 , the first flange portion  152   a  of the liquid ejecting head  1  includes the opening  101  into which the shaft portion  33  is inserted. The opening  101  includes the second opening  102  and a second engaged portion  103 . 
     The second opening  102  is a wall portion that forms a hole to penetrate the first flange portion  152   a . As illustrated in  FIG. 12 , a shape in plan view of the hole defined by the second opening  102  is a shape in conformity to a longitudinal direction of the first flange portion  152   a . The hole defined by the second opening  102  corresponds to the shaft portion  33  and the engaging portion  32  of the fixing member  3 , and is formed such that the shaft portion  33  and the engaging portion  32  can be inserted into the hole. 
     As illustrated in  FIG. 7 , the second engaged portion  103  is located at a position in the z2 direction relative to the second opening  102 . The second engaged portion  103  is a wall portion that forms a groove open to a surface in the z2 direction of the first flange portion  152   a . The groove defined by the second engaged portion  103  communicates with the hole defined by the second opening  102 . Moreover, as illustrated in  FIG. 12 , the groove defined by the second engaged portion  103  extends in the y1 direction in plan view, and intersects with the hole defined by the second opening  102 . In the example illustrated in  FIG. 12 , the groove defined by the second engaged portion  103  is orthogonal to the hole defined by the second opening  102  in plan view. 
       FIG. 13  is a perspective view of the engaged member  25  illustrated in  FIG. 7 .  FIG. 14  is a cross-sectional view of the engaged member  25  illustrated in  FIG. 7 .  FIG. 15  is a plan view of the engaged member  25  illustrated in  FIG. 7 . The engaged member  25  illustrated in  FIGS. 13 to 15  is a member to be engaged with the engaging portion  32  of the fixing member  3 . The material of the engaged member  25  is aluminum, for example. Here, the material of the engaged member  25  may be either a metal other than aluminum or a resin. 
     As illustrated in  FIGS. 7 and 9 , the engaged member  25  is disposed in the recess  210  of the body portion  21 . A surface in the z1 direction of the body portion  21  and a surface in the z1 direction of the engaged member  25  are located at the same position. Accordingly, a substantially flat surface is formed from the surface in the z1 direction of the body portion  21  and the surface in the z1 direction of the engaged member  25 . As illustrated in  FIGS. 14 and 15 , the engaged member  25  includes two screw openings  290  and an opening  201 . The opening  201  is located between the two screw openings  290  in plan view. 
     The two screw openings  290  are wall portions that form holes to penetrate the engaged member  25 . A screw member  29  is inserted into each screw opening  290 . A tip end of the screw member  29  is inserted into a screw hole formed in the body portion  21 . Accordingly, the engaged member  25  that is provided separately from the body portion  21  is fixed to the body portion  21  by using the screw members  29 . Thus, the engaged member  25  is attachable to and detachable from the body portion  21 . Since the engaged member  25  is attachable and detachable, the engaged member  25  can be replaced easily when the engaged member  25  develops scratches as a consequence of repeating replacement of the liquid ejecting heads  1  or when the engaged member  25  causes ink adhesion and the like. 
     The opening  201  is a wall portion that forms a hole to penetrate the engaged member  25  in the z1 direction. The opening  201  includes a third opening  202 , a first engaged portion  203 , a fourth opening  204 , a fifth opening  205 , and regulating portions  206 . 
     As illustrated in  FIG. 14 , the third opening  202 , the first engaged portion  203 , the fourth opening  204 , and the fifth opening  205  collectively form part of a hole to penetrate the engaged member  25  in the z1 direction. The third opening  202 , the first engaged portion  203 , the fourth opening  204 , and the fifth opening  205  are arranged in this order in the z1 direction. Respective holes formed by the third opening  202 , the first engaged portion  203 , the fourth opening  204 , and the fifth opening  205  communicate with one another. 
     As illustrated in  FIG. 15 , a shape in plan view of the hole defined by the third opening  202  is a shape in conformity to the y1 direction being a width direction of the engaged member  25 . The hole defined by the third opening  202  corresponds to the shaft portion  33  and the engaging portion  32  of the fixing member  3 , and is formed such that the shaft portion  33  and the engaging portion  32  can be inserted into the hole. Moreover, the hole of the third opening  202  is open in the z2 direction of the engaged member  25 . 
     As illustrated in  FIG. 13 , the first engaged portion  203  is also a groove formed in the engaged member  25 . To be more precise, the first engaged portion  203  is a groove formed in a surface of the third opening  202  on an opposite side from a surface of the third opening  202  opposed to the second opening  102 . The first engaged portion  203  is engaged with the engaging portion  32 . As illustrated in  FIG. 15 , a shape in plan view of the groove defined by the first engaged portion  203  is a shape in conformity to a longitudinal direction of the engaged member  25 . The groove defined by the first engaged portion  203  intersects with the hole defined by the third opening  202  in plan view. In the example illustrated in  FIG. 13 , the groove defined by the first engaged portion  203  is orthogonal to the hole defined by the third opening  202  in plan view. Moreover, the groove defined by the first engaged portion  203  corresponds to the engaging portion  32  of the fixing member  3 , and is formed such that the engaging portion  32  can be inserted to the groove. 
     As illustrated in  FIGS. 13 and 15 , the hole defined by the fourth opening  204  is open in the y1 direction and the y2 direction of the engaged member  25 . A length in the x1 direction of the hole defined by the fourth opening  204  is larger than a length in the x1 direction of the first engaged portion  203 . Meanwhile, the hole defined by the fifth opening  205  is open in the z1 direction of the engaged member  25  and open in the y1 direction and the y2 direction of the engaged member  25 . A length in the x1 direction of the hole defined by the fifth opening  205  is smaller than a length in the x1 direction of the fourth opening  204 . Here, the fourth opening  204  and the first engaged portion  203  may be collectively regarded as the “first engaged portion”, or the fifth opening  205 , the fourth opening  204 , and the first engaged portion  203  may be collectively regarded as the “first engaged portion”. 
     As illustrated in  FIGS. 13 and 15 , the two regulating portions  206  are wall portions provided to the fourth opening  204 . One of the two regulating portions  206  is located at a position in the y1 direction relative to the first engaged portion  203  in plan view while the other regulating portion  206  is located at a position in the y2 direction relative to the first engaged portion  203  in plan view. Moreover, the two regulating portions  206  are point-symmetrically disposed with respect to the center in plan view of the groove defined by the first engaged portion  203 . These regulating portions  206  regulate rotation in the x-y plane of the engaging portion  32  of the fixing member  3 . 
     As described above, the liquid ejecting apparatus  100  includes the liquid ejecting head  1 , the holding member  2 , the elastic member  4 , and the fixing member  3 . Moreover, the liquid ejecting head  1  is fixed to the holding member  2  by the engaging portion  32  being brought into engagement with the first engaged portion  203  such that the first opening  401  included in the elastic member  4  and the second opening  102  included in the liquid ejecting head  1  are disposed between the head portion  31  and the engaging portion  32  included in the fixing member  3 . In this way, it is possible to fix the liquid ejecting head  1  to the holding member  2  easily without using the screws as in the related art. Hence, it is possible to attach and replace the liquid ejecting head  1  easily. 
     When using the screws as in the related art, it is necessary to conduct three operations at the same time, namely, an operation to press the liquid ejecting head  1  against the holding member  2 , an operation to hold the screws, and an operation to fix the screws with a tool such as a screw driver. In contrast, the user of the fixing member  3  makes it possible to fix the liquid ejecting head  1  to the holding member  2  easily by conducting an operation to rotate the fixing member  3  in the x-y plane while holding the liquid ejecting head  1 . Thus, this embodiment reduces the number of operations as compared to the related art, so that the attachment and replacement of the liquid ejecting head  1  can be carried out easily. 
     In addition, the liquid ejecting apparatus  100  includes the elastic members  4 . Thus, it is possible to stably fix the liquid ejecting head  1  to the holding member  2  by using elastic force of the elastic members  4  as compared to the case of not providing the elastic members  4 . Accordingly, although the screw fastening of the related art cannot stabilize the liquid ejecting head  1  over time due to loosening of the screws, the fixation using the fixing members  3  can maintain the state of stable fixation of the liquid ejecting head  1  for a long period. Moreover, the use of the fixing members  3  and the elastic members  4  can reduce the number of locations to be fixed. Accordingly, it is possible to significantly reduce time required for the fixation work. Furthermore, it is possible to fix the liquid ejecting head  1  easily to the holding member  2  by using the fixing members  3 . Accordingly, the liquid ejecting head  1  can be fixed to the holding member  2  without dropping the liquid ejecting head  1 , the fixing members  3 , and the like even in a state where the liquid ejecting head  1  is located below the holding member  2  in the gravitational direction, or in other words, in a state where liquid ejecting head  1  cannot be placed on the holding member  2 . 
     1-4. Method of Fixing Liquid Ejecting Head  1  to Holding Member  2   
     A method of manufacturing the liquid ejecting apparatus  100  includes the steps of preparing the liquid ejecting head  1 , the holding member  2 , the elastic members  4 , and the fixing members  3 , and fixing the liquid ejecting head  1  to the holding member  2 . In the following, a method of fixing the liquid ejecting head  1  to the holding member  2  will be described. The method of fixing the liquid ejecting head  1  to the holding member  2  includes the steps of fixing the elastic member  4  to the liquid ejecting head  1 , and fixing the liquid ejecting head  1  to the holding member  2 . 
     Each of  FIGS. 16 and 17  is a diagram for explaining fixation of the elastic member  4  to the liquid ejecting head  1 . As illustrated in  FIG. 16 , the hole defined by the first opening  401  of the elastic member  4  is brought into a state of overlapping the hole defined by the second opening  102  of the liquid ejecting head  1  in plan view to begin with. Then, the engaging portion  32  and the shaft portion  33  of the fixing member  3  are inserted into the first opening  401  and the second opening  102 . 
     In the state of inserting the shaft portion  33  into the first opening  401  and the second opening  102 , the hole defined by the first opening  401 , the hole defined by the second opening  102 , and the engaging portion  32  overlap one another in plan view. From another point of view, a second position being a rotational position where the engaging portion  32  is insertable into the second opening  102  is the same as a rotational position where the engaging portion  32  is insertable into the first opening  401 . For this reason, the fixing member  3  does not have to be rotated when inserting the fixing member  3  into the first opening  401  and the second opening  102  as illustrated in  FIG. 16 . In other words, it is possible to insert the engaging portion  32  of the fixing member  3  easily into the first opening  401  and the second opening  102  without rotating the fixing member  3 . 
     Next, as illustrated in  FIG. 17 , the engaging portion  32  is brought into engagement with the second engaged portion  103  by rotating the fixing member  3  in the x-y plane. In this embodiment, the engaging portion  32  is rotated by 90° in the x-y plane by manipulating the head portion  31 . The first opening  401  and the second opening  102  are located between the head portion  31  and the engaging portion  32  in the state of bringing the engaging portion  32  into engagement with the second engaged portion  103 . 
     As described above, each of the first flange portion  152   a  and the second flange portion  152   b  of the liquid ejecting head  1  includes the second engaged portion  103  engageable with the engaging portion  32 . Therefore, the elastic member  4  can be fixed to the liquid ejecting head  1  by bringing the engaging portion  32  into engagement with the second engaged portion  103 . Accordingly, the elastic member  4  can be fixed to the liquid ejecting head  1  before fixing the liquid ejecting head  1  to the holding member  2 . In other words, it is possible to bring the second engaged portion  103  of the liquid ejecting head  1  into engagement with the engaging portion  32  before bringing the first engaged portion  203  of the holding member  2  to be described later into engagement with the engaging portion  32 . In this way, the elastic member  4  can be fixed to the liquid ejecting head  1  without dropping any of the liquid ejecting head  1  and the elastic member  4 . Moreover, since the hole of the second opening  102  intersects with the groove of the second engaged portion  103  in plan view as described in this embodiment, the engaging portion  32  can be fitted into the second engaged portion  103 . 
     Each of  FIGS. 18, 19, and 20  is a diagram for explaining fixation of the liquid ejecting head  1  to the holding member  2 . As illustrated in  FIG. 18 , the elastic member  4 , the liquid ejecting head  1 , and the holding member  2  are lapped over such that the first opening  401  is orthogonal to the third opening  202  in plan view by conducting positioning with the positioning pins  211  in a state where the elastic member  4  is fixed to the liquid ejecting head  1  by using the fixing member  3 . In this lapped state, the engaging portion  32  of the fixing member  3  is inserted into the third opening  202  of the holding member  2  as illustrated in  FIG. 18 . 
     Next, as illustrated in  FIG. 19 , the fixing member  3  is pushed straight in the z2 direction, thereby inserting the shaft portion  33  into the third opening  202  and inserting the engaging portion  32  into the fourth opening  204 . 
     When the elastic member  4 , the liquid ejecting head  1 , and the holding member  2  are lapped over such that the first opening  401  is orthogonal to the third opening  202  in plan view, the engaging portion  32 , the second engaged portion  103 , and the third opening  202  overlap in plan view. From another point of view, a rotational position where the engaging portion  32  is brought into engagement with the second engaged portion  103  is the same as a first position being a rotational position where the engaging portion  32  is insertable into the third opening  202 . For this reason, the engaging portion  32  can be inserted into the third opening  202  by pushing the fixing member  3  straight in the z2 direction in the state where the elastic member  4  is fixed to the liquid ejecting head  1  by using the fixing member  3  as illustrated in  FIG. 19 . This configuration has good workability. 
     Next, as illustrated in  FIG. 20 , the engaging portion  32  is brought into engagement with the first engaged portion  203  such that the first opening  401  and the second opening  102  are disposed between the head portion  31  and the engaging portion  32  while the elastic member  4  is pressed with the head portion  31 . Specifically, the fixing member  3  is rotated in the x-y plane about the shaft portion  33  as a rotational axis while the elastic member  4  is pressed with the head portion  31 . To be more precise, the fixing member  3  is rotated by 90°. In this way, the liquid ejecting head  1  is fixed to the holding member  2 . 
     By bringing the engaging portion  32  into engagement with the first engaged portion  203  such that the first opening  401  and the second opening  102  are disposed between the head portion  31  and the engaging portion  32  as described above, it is possible to fix the liquid ejecting head  1  to the holding member  2  easily without using the screws as in the related art. Thus, the liquid ejecting head  1  can be attached or replaced easily. Moreover, since it is only necessary to rotate the fixing member  3  by an angle below 180°, or more specifically equal to or below 90°, this operation greatly saves the labor of a worker. 
     In particular, the engaging portion  32  is engaged with the first engaged portion  203  by rotating the fixing member  3  in the x-y plane about the shaft portion  33  as the rotational axis in the state where the shaft portion  33  is inserted into the second opening  102  and the third opening  202 . As a consequence, the liquid ejecting head  1  is fixed to the holding member  2 . As described above, the liquid ejecting head  1  can be fixed to the holding member  2  easily by conducting the simple operation to rotate the fixing member  3  in the x-y plane. Thus, this operation greatly saves the labor of the worker. 
     Moreover, the engaging portion  32  is fitted into the first engaged portion  203  in this embodiment. This configuration can keep the state of engagement of the engaging portion  32  with the first engaged portion  203  from being released by vibration and other factors during printing after the liquid ejecting head  1  is fixed to the holding member  2 . Accordingly, a favorable state of fixation of the liquid ejecting head  1  to the holding member  2  stably continues for a long period. 
     Meanwhile, as illustrated in  FIG. 20 , the second opening  102  is disposed below the holding member  2  in the gravitational direction. Moreover, the direction of insertion of the fixing member  3  is a direction upward from below in the gravitational direction. According to the method of fixing the liquid ejecting head  1  by using the fixing member  3 , it is not necessary to conduct the three operations at the same time unlike the related art, namely, the operation to press the liquid ejecting head  1 , the operation to hold the screws, and the operation to fix the screws with the tool. As a consequence, the liquid ejecting head  1  can be easily fixed to the holding member  2  even in the case of fixing the liquid ejecting head  1  to the holding member  2  upward from below in the gravitational direction, or in other words, in a case of bad workability where the liquid ejecting head  1  cannot be fixed to the holding member  2  while placing the liquid ejecting head  1  on the holding member  2 . 
     Moreover, as described above, the hole of the third opening  202  included in the holding member  2  intersects with the hole of the second opening  102  included in the liquid ejecting head  1  in plan view. From another point of view, the first position being the rotational position where the engaging portion  32  is insertable into the third opening  202  is different from the second position being the rotational position where the engaging portion  32  is insertable into the second opening  102 . For this reason, by rotating the fixing member  3  to the first position different from the second position, the worker can conduct the operation stably for inserting the fixing member  3  into the third opening  202  because the fixing member  3  does not drop even when the worker does not hold the fixing member  3 . Meanwhile, the engaging portion  32  is located at the first position when the engagement of the engaging portion  32  with the first engaged portion  203  is released by rotating the fixing member  3  in the x-y plane in order to detach the liquid ejecting head  1  from the holding member  2 . Accordingly, it is possible to keep the fixing member  3  from dropping due to the engaging portion  32  passing through the second opening  102  at the time of the release. This effect is particularly prominent in the case of fixing the liquid ejecting head  1  to the holding member  2  upward from below in the gravitational direction as in this embodiment because the fixing member  3  is prone to drop in this case. 
     Meanwhile, the holding member  2  includes the regulating portions  206  to regulate the rotation of the fixing member  3 . Accordingly, when the fixing member  3  is rotated in the x-y plane, it is possible to bring the engaging portion  32  into engagement with the first engaged portion  203  easily just by releasing the push of the fixing member  3  in the z1 direction at a position where the engaging portion  32  butts one of the regulating portions  206 . 
     In the meantime, the head portion  31  includes a groove  311  to which the tool for rotating the fixing member  3  is fitted. Accordingly, the liquid ejecting head  1  can be easily fixed to the holding member  2  by manipulating the fixing member  3  while using the tool such as a screw driver and a wrench having a shape corresponding to the groove  311 . Moreover, the groove  311  is open in the z1 direction of the head portion  31 . Hence, the liquid ejecting head  1  can be attached or replaced easily by using the tool that extends in the z1 direction even when there is not an enough space in the x-y plane. 
     Meanwhile, the elastic members  4  are provided separately from the liquid ejecting head  1  and the holding member  2 . Each elastic member  4  is neither fixed to any of the liquid ejecting head  1  and the holding member  2 , nor fixed by using a component other than the fixing member  3 . Accordingly, the elastic member  4  is easily replaceable when the elastic member  4  is deteriorated by replacing the liquid ejecting heads  1  a number of times, for example. Moreover, since the elastic member  4  is not fixed to the liquid ejecting head  1  or the holding member  2 , it is easier to elastically deform the elastic member  4  and to push the fixing member  3  into the fourth opening  204 . Furthermore, by providing the elastic member  4  separately without fixation to the liquid ejecting head  1 , the elastic member  4  can also be used in another aspect in which the elastic member  4  is provided on the surface on the opposite side of the surface provided with the first flange portion  152   a  and the second flange portion  152   b . In this way, the layout of the elastic member  4  relative to the first flange portion  152   a  and the second flange portion  152   b  can be changed easily. In this embodiment, the liquid ejecting head  1  is fixed to the holding member  2  from below in the vertical direction. On the other hand, the layout of the elastic member  4  can be easily changed when the liquid ejecting head  1  is fixed to the holding member  2  from above in the vertical direction, for example. 
     In the meantime, as described above, the length of the shaft portion  33  is set such that the elastic member  4  does not cause plastic deformation. Meanwhile, in the state where the engaging portion  32  is engaged with the first engaged portion  203 , a distance from the surface of the head portion  31  in contact with the elastic member  4  to the second opening  102  is set below an amount of deformation in the z1 direction of the elastic member  4  when the elastic member  4  is deformed to an upper yield point that represents a limit of elasticity thereof. In this way, it is possible to prevent the elastic member  4  from being plastically deformed even when a load in the z1 direction is applied to the liquid ejecting head  1  in a case where an externally provided wiring member is inserted in the z1 direction and coupled to the connector  112  of the liquid ejecting head  1 , for example, and when the elastic member  4  is deformed in the z-axis direction by that load. 
     Meanwhile, the holder  15  and the holding member  2  are formed from materials having different linear expansion coefficients, respectively. To be more precise, the body portion  21  of the holding member  2  that is elongate in the x-axis direction and the second opening  102  of the holder  15  are formed from materials having different linear expansion coefficients, respectively. Even when the holder  15  or the holding member  2  becomes deformed due to the difference in linear expansion coefficient therebetween, the provision of the elastic member  4  can stably maintain the state of fixation of the liquid ejecting head  1  to the holding member  2  as compared to the case of not providing the elastic member  4 . Thus, the materials of the holder  15  and the holding member  2  can be selected from appropriate materials, respectively. In this way, the degree of design freedom can be improved. 
     In the meantime, the holding member  2  is located at the position in the z2 direction relative to the first flange portion  152   a  of the liquid ejecting head  1 . For this reason, it is possible to reduce the holding member  2  in size as compared to the case of locating the holding member  2  sideways of the first flange portion  152   a.    
     2. SECOND EMBODIMENT 
     A second embodiment will be described. Note that in the following explanations of examples, the elements having the same functions as those of the first embodiment will be denoted by the reference signs used in the description of the first embodiment and detailed explanations thereof will be omitted as appropriate. 
       FIG. 21  is a perspective view illustrating a fixing member  3 A of the second embodiment. This embodiment is the same as the first embodiment except that the fixing member  3 A is used instead of the fixing member  3 . In the following, features of the fixing member  3 A which are different from those of the fixing member  3  of the first embodiment will be described while omitting the explanations of the same features as appropriate. 
     The fixing member  3 A illustrated in  FIG. 21  includes a head portion  31 A instead of the head portion  31  of the first embodiment. The head portion  31 A is a lever for rotating the fixing member  3 A in the x-y plane. Since the head portion  31 A is the lever, it is possible to fix the liquid ejecting head  1  to the holding member  2  by the fixing member  3 A without using a tool. Accordingly, the liquid ejecting head  1  can be attached and replaced more easily as compared to the case of using the tool. 
     Specifically, the head portion  31 A of the fixing member  3 A is formed to be rotatable in a direction indicated with an arrow A11 and in a direction indicated with an arrow A12 about the shaft portion  33 . For example, the shaft portion  33  of the fixing member  3 A is inserted into the first opening  401  and the second opening  102  in the state of rotating 90° in the A11 direction from the state of the fixing member  3 A illustrated in  FIG. 21 . Next, the engaging portion  32  is brought into engagement with the second engaged portion  103  by rotating the head portion  31 A in the direction indicated with the arrow A12 from the state after rotating 90° in the A11 direction from the state of the fixing member  3 A illustrated in  FIG. 21 . Then, the engaging portion  32  is brought into engagement with the first engaged portion  203  by pushing the fixing member  3 A in the z2 direction, and restoring the state of the fixing member  3 A illustrated in  FIG. 21  from the state of the fixing member  3 A illustrated in  FIG. 21  back to the state of rotating 90° in the A11 direction by rotating the head portion  31 A in the direction indicated with the arrow A11. By carrying out the above-described operations of the head portion  31 A, it is possible to attach and replace the liquid ejecting head  1  easily. 
     Meanwhile, in the state where the liquid ejecting head  1  is fixed to the holding member  2 , the fixing member  3 A is in the state of being rotated by 90° in the A11 direction from the state of the fixing member  3 A illustrated in  FIG. 21 . This configuration makes it possible to achieve reduction in size of the head unit  10 . 
     3. THIRD EMBODIMENT 
     A third embodiment will be described. Note that in the following explanations of examples, the elements having the same functions as those of the first embodiment will be denoted by the reference signs used in the description of the first embodiment and detailed explanations thereof will be omitted as appropriate. 
       FIG. 22  is a cross-sectional view illustrating a fixing member  3 B of the third embodiment.  FIG. 23  is a cross-sectional view illustrated an exploded state of the fixing member  3 B of the third embodiment. This embodiment is the same as the first embodiment except that the fixing member  3 B is used instead of the fixing member  3 . In the following, features of the fixing member  3 B which are different from those of the fixing member  3  of the first embodiment will be described while omitting the explanations of the same features as appropriate. 
     As illustrated in  FIGS. 22 and 23 , the fixing member  3 B is formed from more than one member. Specifically, the fixing member  3 B includes a first member  301  and a second member  302 . The first member  301  and the second member  302  are separable and assemblable. The first member  301  includes the head portion  31  and a first shaft portion  33 B. The second member  302  includes the engaging portion  32  and a second shaft portion  34 . The “shaft portion” is formed from the first shaft portion  33 B and the second shaft portion  34 . That is to say, in this embodiment, the “shaft portion” is formed from both the first member  301  and the second member  302 . 
     As illustrated in  FIG. 23 , the first shaft portion  33 B includes a tip end portion  331  that is engageable with the second shaft portion  34 . The tip end portion  331  is located at an opposite end from the head portion  31  of the first shaft portion  33 B. A male screw is formed on an outer peripheral surface of the tip end portion  331 , for example. Meanwhile, the second shaft portion  34  is formed to be engageable with the tip end portion  331 . A female screw is formed on an inner peripheral surface of the second shaft portion  34 , for example. The first member  301  is fixed to the second member  302  as illustrated in  FIG. 22  by fitting the second member  302  into the first member  301 . 
     When the liquid ejecting head  1  is fixed to the holding member  2  by using the fixing member  3 B, the first member  301  is fixed to the second member  302  in the state where the “shaft portion” that is formed from the first shaft portion  33 B included in the first member  301  and the second shaft portion  34  included in the second member  302  is inserted into both the first opening  401  and the second opening  102 . Specifically, the first member  301  is fixed to the second member  302  in the state where the “shaft portion” formed from the first shaft portion  33 B and the second shaft portion  34  is inserted into both the first opening  401  and the second opening  102 . Meanwhile, the shapes of the respective holes of the first opening  401  and the second opening  102  are designed in conformity to shapes of the first shaft portion  33 B and the second shaft portion  34 , for example. Moreover, the shapes of the respective holes of the first opening  401  and the second opening  102  are formed into such shapes that block insertion of the engaging portion  32  and the head portion  31 . 
     Accordingly, unlike the first embodiment, the rotating operation of the fixing member  3 B is not required in a period until the fixing member  3 B is inserted into both the first opening  401  and the second opening  102 . Moreover, since the engaging portion  32  and the head portion  31  have the shapes that cannot be inserted into the respective holes of the first opening  401  and the second opening  102 , the fixing member  3 B and the elastic member  4  are kept from coming off the liquid ejecting head  1  after the first member  301  is fixed to the second member  302 . Accordingly, it is possible to prevent the fixing member  3 B and the elastic member  4  from dropping in the course of fixation of the liquid ejecting head  1 . Moreover, the shapes of the respective holes of the first opening  401  and the second opening  102  can be designed in conformity to the shapes of the first shaft portion  33 B and the second shaft portion  34 . To be more precise, the respective holes can be formed into circular holes in conformity to transverse sectional shapes of the first shaft portion  33 B and the second shaft portion  34 , for example. As a consequence, it is possible to process the respective members easily and to improve mechanical strengths of the respective members, or of the elastic member  4  in particular. 
     Note that the method of fixing the first member  301  to the second member  302  is not limited only to screw fastening and the fixing method may adopt adhesion or press fitting, for example. 
     Although the “shaft portion” is formed from both the first member  301  and the second member  302  in this embodiment, the “shaft portion” may be formed from only one of the first member  301  and the second member  302 . Specifically, although the “shaft portion” is formed from the first shaft portion  33 B and the second shaft portion  34  in this embodiment, the “shaft portion” may be formed from only one of the first shaft portion  33 B and the second shaft portion  34 . For example, when a male screw is formed at an end portion of the second shaft portion  34  of the second member  302  on the opposite side of the engaging portion  32 , and the fixing member  3 B is formed by bringing the male screw into engagement with a female screw formed inside the head portion  31 , the first member  301  does not include the first shaft portion  33 B to serve as part of the “shaft portion”. Accordingly, the “shaft portion” is formed only from the second shaft portion  34  of the second member  302 . In other words, the “shaft portion” is formed only from the second member  302  out of the first member  301  and the second member  302 . 
     4. MODIFIED EXAMPLES 
     The above-described embodiments may be modified in various modes. Specific aspects of modifications applicable to the above-described embodiments will be discussed below as examples. Two or more aspects selected arbitrarily from the following examples may be combined as appropriate so far as those aspects do not conflict with one another. 
     4-1. First Modified Example 
       FIG. 24  is a diagram schematically illustrating a liquid ejecting head  1 C and a holding member  2 C according to a first modified example. In the above-described embodiments, the first flange portion  152   a  included in the liquid ejecting head  1  is located at the position in the z1 direction relative to the holding member  2 . Meanwhile, in the example illustrated in  FIG. 24 , the first flange portion  152   a  is located at a position in the z2 direction relative to part of the holding member  2 . 
     In this case, the holding member  2 C includes a second opening  271  and a second engaged portion  272 . The second opening  271  has a structure, functions, and effects which are the same as those of the second opening  102  of the first embodiment. The second engaged portion  272  has a structure, functions, and effects which are the same as those of the second engaged portion  103  of the first embodiment. Meanwhile, the liquid ejecting head  1 C includes a third opening  171  and a first engaged portion  172 . The third opening  171  has a structure, functions, and effects which are the same as those of the third opening  202  of the first embodiment. The first engaged portion  172  has a structure, functions, and effects which are the same as those of the first engaged portion  203  of the first embodiment. 
     Accordingly, in the first modified example as well, the liquid ejecting head  1 C is fixed to the holding member  2 C by the engaging portion  32  being brought into engagement with the first engaged portion  172  of the liquid ejecting head  1 C such that the first opening  401  included in the elastic member  4  and the second opening  271  included in the holding member  2 C are disposed between the head portion  31  and the engaging portion  32  included in the fixing member  3  as with the first embodiment. 
     Note that both a longitudinal direction of the first engaged portion  172  and a longitudinal direction of the second engaged portion  272  are illustrated in line with the x1 direction for facilitating the understanding of the description in  FIG. 24 . Nonetheless, as with the above-described embodiments, the longitudinal direction of the first engaged portion  172  may intersect with the longitudinal direction of the second engaged portion  272  in order to prevent the fixing member  3  from dropping. 
     4-2. Second Modified Example 
       FIG. 25  is a diagram illustrating a layout of the liquid ejecting head  1  and the holding member  2  of the first embodiment.  FIG. 26  is a diagram illustrating a layout of a liquid ejecting head  1 D and a holding member  2 D of a second modified example. In the first embodiment, the holding member  2  is located at the position in the z2 direction relative to the first flange portion  152   a  as illustrated in  FIG. 25 . In this case, the fixing member  3  is attached to the liquid ejecting head  1  and the holding member  2  upward from below in the gravitational direction. On the other hand, when part of the holding member  2  is located at a position in the z1 direction relative to the first flange portion  152   a  of the liquid ejecting head  1 D as illustrated in  FIG. 26 , the fixing member  3  may be attached to the liquid ejecting head  1  and the holding member  2  from above downward in the gravitational direction. 
     Moreover, since the holding member  2  is located at the position in the z2 direction relative to the first flange portion  152   a  as illustrated in  FIG. 25 , the holding member  2  is not disposed sideways of the second opening  102 . Since the holding member  2  is located at the position in the z2 direction relative to the first flange portion  152   a , it is easier to reduce the size of the liquid ejecting head  1  as compared to the example illustrated in  FIG. 26 . Since a space inside the holding member  2  can be reduced as illustrated in  FIG. 25 , it is easier to reduce the size of the liquid ejecting head  1 . Moreover, by fixing the fixing member  3  upward from below in the gravitational direction, a distance between the ejecting surface S 11  and the fixing member  3  is reduced. Thus, it is possible to improve positional accuracy of the nozzles. 
     4-3. Third Modified Example 
       FIG. 27  is a diagram schematically illustrating a liquid ejecting head  1 E and a holding member  2 E of a third modified example. In the example illustrated in  FIG. 27 , the holding member  2 E is located above the first flange portion  152   a  and the base portion  151  in the gravitational direction. In the case of this example, the fixing member  3  can be attached to the liquid ejecting head  1 E and the holding member  2 E from above downward in the gravitational direction. 
     In this case, the holding member  2 E includes a second opening  273 . The second opening  273  has a structure, functions, and effects which are the same as those of the second opening  102  of the first embodiment. Here, the “second engaged portion” may be omitted when the liquid ejecting head  1 E is fixed to the holding member  2 E from above downward in the gravitational direction. Meanwhile, the liquid ejecting head  1 E includes a third opening  173  and a first engaged portion  174 . The third opening  173  has a structure, functions, and effects which are the same as those of the third opening  202  of the first embodiment. The first engaged portion  174  has a structure, functions, and effects which are the same as those of the first engaged portion  203  of the first embodiment. 
     4-4. Fourth Modified Example 
       FIG. 28  is a diagram schematically illustrating a liquid ejecting head  1 F and a holding member  2 F of a fourth modified example. In the example illustrated in  FIG. 28 , the holding member  2 F is located above the base portion  151  in the gravitational direction and is located below the first flange portion  152   a  in the gravitational direction. In the case of this example, the fixing member  3  can be attached to the liquid ejecting head  1 F and the holding member  2 F from above downward in the gravitational direction. 
     In this case, the liquid ejecting head  1 F includes a second opening  175 . The second opening  175  has a structure, functions, and effects which are the same as those of the second opening  102  of the first embodiment. Here, the “second engaged portion” may be omitted when the liquid ejecting head  1 F is fixed to the holding member  2 F from above downward in the gravitational direction. Meanwhile, the holding member  2 F includes a third opening  274  and a first engaged portion  275 . The third opening  274  has a structure, functions, and effects which are the same as those of the third opening  202  of the first embodiment. The first engaged portion  275  has a structure, functions, and effects which are the same as those of the first engaged portion  203  of the first embodiment. 
     4-5. Fifth Modified Example 
       FIG. 29  is a diagram schematically illustrating a holding member  2 G of a fifth modified example. As illustrated in  FIG. 29 , the holding member  2 G further includes a second engaged portion  177  in addition to the second opening  102  and the second engaged portion  103 . In other words, the holding member  2 G includes two “second engaged portions”. The second engaged portion  103  is located at a position in the z2 direction of the second opening  102  and the second engaged portion  177  is located at a position in the z1 direction of the second opening  102 . Accordingly, in the example illustrated in  FIG. 29 , the “second engaged portions” are provided in two surfaces of the second opening  102 . For this reason, it is possible to insert the fixing member  3  into the second opening  102  of the holding member  2 G upward from below in the gravitational direction as illustrated in  FIG. 29 , and also to insert the fixing member  3  into the second opening  102  of the holding member  2 G from above downward in the gravitational direction. Hence, the direction of insertion of the fixing member  3  can be changed easily depending on a layout relation between the liquid ejecting head  1  and the holding member  2 G. 
     4-6. Sixth Modified Example 
       FIG. 30  is a diagram schematically illustrating a fixing member  3 H and a liquid ejecting head  1 H of a sixth modified example.  FIG. 31  is a plan view of the fixing member  3 H and the first flange portion  152   a  of the liquid ejecting head  1 H illustrated in  FIG. 30 . In the example illustrated in  FIG. 30 , an engaging portion  32 H included in the fixing member  3 H also functions as the operating portion for performing the rotating operation of the fixing member  3 H in the x-y plane with respect to the liquid ejecting head  1 H when fixing the liquid ejecting head  1 H. Here, the head portion  31  comes into contact with the elastic member  4 . 
     Moreover, the liquid ejecting head  1 H includes a first engaged portion  178  to be engaged with the engaging portion  32 H. The first engaged portion  178  is a protrusion that protrudes in the z2 direction from the first flange portion  152   a.    
     Meanwhile, the second opening  102  of the liquid ejecting head  1 H is configured such that the engaging portion  32 H can be inserted into the opening. As illustrated in  FIG. 31 , the engaging portion  32 H is rotatable in a direction indicated with an arrow A21 and a direction indicated with an arrow A22. 
     For example, the engaging portion  32 H in a state of being located in the second opening  102  is rotated in the direction indicated with the arrow A21, thus locating the engaging portion  32 H at a position indicated in  FIG. 31 . Then, the engaging portion  32 H is brought into engagement with the first engaged portion  178  of the liquid ejecting head  1 H as illustrated in  FIGS. 30 and 31 . Accordingly, in the sixth modified example as well, the liquid ejecting head  1 H is fixed to the holding member  2  by the engaging portion  32 H being brought into engagement with the first engaged portion  178  such that the first opening  401  and the third opening  202  are disposed between the head portion  31  and the engaging portion  32 H included in the fixing member  3 H as with the first embodiment. 
     4-7. Seventh Modified Example 
       FIG. 32  is a diagram schematically illustrating an elastic member  41  of a seventh modified example. The elastic member  41  illustrated in  FIG. 32  is a spring member having a flat plate shape without any bent portion. Meanwhile, the liquid ejecting head  1 H includes protrusions  154  that protrude in the z2 direction from the first flange portion  152   a . The elastic member  41  is disposed on the protrusions  154 . The use of the elastic member  41  can improve the positional accuracy of the liquid ejecting head  1 H relative to the holding member  2  as compared to the case of using the elastic member  4  of the first embodiment. 
     4-8. Eighth Modified Example 
       FIG. 33  is a diagram schematically illustrating an elastic member  4 J of an eighth modified example. The elastic member  4 J illustrated  FIG. 33  includes a flat plate portion  44  having a flat plate shape without any bent portion, and protrusions  43  that protrude in the z1 direction from the flat plate portion  44 . The protrusions  43  come into contact with the liquid ejecting head  1 . The use of the elastic member  4 J can improve the positional accuracy of the liquid ejecting head  1  relative to the holding member  2  as compared to the case of using the elastic member  4  of the first embodiment. 
     4-9. Ninth Modified Example 
       FIG. 34  is a plan view schematically illustrating a fixing member  3 K of a ninth modified example. In the example illustrated in  FIG. 34 , an engaging portion  32 K of the fixing member  3 K includes three projections  325  that extend in the x-y plane from the shaft portion  33  in plan view. 
     A shape of this “engaging portion” may take on any shape as long as the shape is engageable with the “first engaged portion”. Nevertheless, by proving the engaging portion  32 K with the projections  325  as illustrated in  FIG. 34 , it is possible to reduce a rotation angle of the fixing member  3  in the x-y plane as compared to the engaging portion  32  of the first embodiment. In the first embodiment, the fixing member  3  is rotated by 90° when fixing the liquid ejecting head  1  to the holding member  2 . In contrast, the use of the fixing member  3 K illustrated in  FIG. 34  can reduce the rotation angle of the fixing member  3 K to 60°, for example. Thus, the liquid ejecting head  1  can be fixed to the holding member  2  more easily. 
     In the meantime, the “shaft portion” may also take on a shape in plan view other than the circular shape as long as such a shape does not affect the functions of the shaft portion. Moreover, the “head portion” may also take on a shape in plan view other than the circular shape as long as such a shape does not affect the functions of the head portion. 
     4-10. Tenth Modified Example 
       FIG. 35  is a schematic diagram illustrating a liquid ejecting apparatus  100 L of a tenth modified example. The liquid ejecting apparatus  100 L illustrated in  FIG. 35  is a printing apparatus of a serial type. The liquid ejecting apparatus  100 L includes the liquid ejecting heads  1  arranged in the direction of transportation DM of the medium PP. The liquid ejecting heads  1  are arranged in the x-axis direction. 
     The liquid ejecting apparatus  100 L includes a head transportation mechanism  95 . The head transportation mechanism  95  includes a carriage  951  and an endless belt  952 . The carriage  951  holds liquid ejecting heads  1 . The carriage  951  is coupled to the endless belt  952 . The carriage  951  is transported by the endless belt  952  so as to reciprocate in a main scanning direction. 
     When a printing operation is executed, the liquid ejecting apparatus  100 L ejects the ink from the liquid ejecting heads  1  while reciprocating the liquid ejecting heads  1  in the main scanning direction and transporting the medium PP in a vertical scanning direction being intersecting with the main scanning direction at the same time. As a consequence, dots corresponding to print data are formed on the medium PP and an image is thus printed on the medium PP. 
     The liquid ejecting heads  1  are also applied to the above-described liquid ejecting apparatus  100 L of the serial type. 
     4-11. Other Modified Examples 
     In the above-described embodiments, the groove  311  is formed at the head portion  31  of the fixing member  3 . Here, a shape of the groove  311  is not limited to a particular shape. For example, the groove  311  may take on a polygonal shape such as a rectangle and a hexagon, a cross shape, an I-shape, and the like. 
     Meanwhile, the elastic member  4  is the plate spring in the above-described embodiments. Instead, the elastic member  4  may be any of a coil spring, a disc spring, and a waved washer, for example. Nonetheless, the use of the plate spring can easily shorten the distance between the fixing member  3  and the liquid ejecting head  1  as compared to the case of using the coil spring. Here, an attempt to dispose the first flange portion  152   a  close to the ejecting surface S 11  in order to improve the positioning accuracy results in the reduced distance from the ejecting surface S 11  to the first flange portion  152   a  in a direction of ejection. In this case, it is difficult to use the coil spring that requires a certain dimension in the z1 direction which is the direction of ejection. In contrast, the plate spring bears a high load and requires a small dimension in the direction of ejection, and is therefore suitable. 
     In the above-described embodiments, the second flange portion  152   b  includes the two positioning holes  1521 . Instead, the two positioning holes  1521  may be provided to the first flange portion  152   a . In this case, the elastic member  4  is disposed between the two positioning holes  1521  in plan view. 
     In the above-described embodiments, the engaged member  25  is provided with the regulating portions  206 . However, the engaged member  25  does not always have to be provided with the regulating portions  206 . In this way, it is possible to rotate the fixing member  3  in both a clockwise direction and a counterclockwise direction in the x-y plane. 
     It is to be understood that the above-described embodiments merely illustrate representative modes of the present disclosure and that the present disclosure is not limited only to the above-described embodiments. Various alterations and additions are possible within the scope not departing from the gist of the present disclosure. 
     Besides the apparatus dedicated to printing, the liquid ejecting apparatuses shown as the examples in the above-described aspects may also be adopted as various apparatuses including a facsimile apparatus, a copier, and the like. As a matter of fact, the usage of the liquid ejecting apparatus is not limited only to printing. For example, a liquid ejecting apparatus that ejects a solution of a coloring material is used as a manufacturing apparatus for forming a color filter of a display device such as a liquid crystal display panel. Meanwhile, a liquid ejecting apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus for forming wiring and electrodes on a wiring board. In the meantime, a liquid ejecting apparatus that ejects a solution of an organic substance related to a biological object is used as a manufacturing apparatus for manufacturing a biochip, for instance.