Patent Publication Number: US-2023147417-A1

Title: Liquid discharge head, liquid discharge device, and liquid discharge apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is based on and claims priority pursuant to 35 U.S.C. § 119(a) to Japanese Patent Application No. 2021-182705, filed on Nov. 9, 2021, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein. 
     BACKGROUND 
     Technical Field 
     The present embodiment relates to a liquid discharge head, a liquid discharge device, and a liquid discharge apparatus. 
     Related Art 
     A liquid discharge head includes, for example, a nozzle plate having multiple nozzles, a chamber member provided with a liquid chamber in communication with a nozzle, an actuator including a piezoelectric element and an electrode, a support substrate bonded to the actuator, and a frame provided with a common chamber from which liquid is supplied to the liquid chamber. 
     Adhesive is used for bonding between members in such a liquid discharge head. For such bonding, types of adhesive and techniques of coating of adhesive are available. 
     For example, an electrostatic actuator and a head frame are bonded together with elastic adhesive. Such a configuration can improve reliability at the time of bonding, reduce cost, and prevent a nozzle plate or substrate from detachment in an electrostatic actuator. 
     SUMMARY 
     A liquid discharge head includes: a first member: and a second member bonded to the first member, wherein the first member has: a first protrusion protruding to the second member, a second protrusion protruding to the second member, the second protrusion having a height different from the first protrusion, the second member includes: a first portion bonded to the first protrusion with a first adhesive; and a second portion bonded to the second protrusion with a second adhesive, the second portion having a height different from the first portion, and a type of the second adhesive is different from a type of the first adhesive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete appreciation of embodiments of the present disclosure and many of the attendant advantages and features thereof can be readily obtained and understood from the following detailed description with reference to the accompanying drawings, wherein: 
         FIG.  1    is a schematic perspective view of an exemplary first member; 
         FIG.  2    is a schematic plan view of the exemplary first member: 
         FIG.  3    is a schematic side view of exemplary bonding between the first member and a second member; 
         FIG.  4    is another schematic side view of the exemplary bonding between the first member and the second member: 
         FIGS.  5 A,  5 B, and  5 C  are, respectively, a schematic plan view of other exemplary bonding between the first member and the second member, a schematic cross-sectional view taken along line A-A of  FIG.  5 A , and a schematic cross-sectional view taken along line B-B of  FIG.  5 A ; 
         FIGS.  6 A and  6 B  are, respectively, a schematic side view and a schematic cross-sectional view each illustrating an exemplary recess that the first member has and an exemplary third protrusion that the second member has; 
         FIGS.  7 A,  7 B, and  7 C  are, respectively, a schematic plan view, a schematic side view, and a schematic cross-sectional view taken along line C-C of  FIG.  7 A  in Comparative Example 1; 
         FIGS.  8 A,  8 B, and  8 C  are, respectively, a schematic plan view, a schematic cross-sectional view taken along line D-D of  FIG.  8 A , and a schematic cross-sectional view taken along line E-E of  FIG.  8 A  in Reference Example 1; 
         FIG.  9    is a schematic cross-sectional view of an example of a liquid discharge head according to the present embodiment: 
         FIG.  10    is a schematic perspective view of an example of a liquid discharge apparatus according to the present embodiment; 
         FIG.  11    is a schematic side view of the example of the liquid discharge apparatus according to the present embodiment; 
         FIG.  12    is a schematic view of another example of the liquid discharge apparatus according to the present embodiment; 
         FIG.  13    is a schematic view of the another example of the liquid discharge apparatus according to the present embodiment; 
         FIG.  14    is a schematic view of an example of a liquid discharge device: and 
         FIG.  15    is a schematic view of another example of the liquid discharge device. 
     
    
    
     The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. Also, identical or similar reference numerals designate identical or similar components throughout the several views. 
     DETAILED DESCRIPTION 
     In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that have a similar function, operate in a similar manner, and achieve a similar result. 
     Referring now to the drawings, embodiments of the present disclosure are described below. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. 
     A liquid discharge head, a liquid discharge device, and a liquid discharge apparatus according to the present embodiment will be described below with reference to the drawings. Note that the present embodiment is not limited to the following embodiments and thus other embodiments, additions, modifications, and deletions can be made within the scope conceivable by those skilled in the art. Any aspects that achieve the function and effect of the present embodiment are to be included in the scope of the present embodiment. 
     Liquid Discharge Head 
     The liquid discharge head according to the present embodiment includes: a first member; and a second member bonded to the first member with adhesive, in which the first member has multiple protrusions protruding to the second member, the multiple protrusions includes two or more types of protrusions different in height, the second member has a portion that is bonded to the multiple protrusions and varies in height depending on a height of each of the multiple protrusions, and the adhesive includes two or more types of adhesive. 
     An embodiment of the present embodiment will be described. 
     Note that a first member and a second member bonded together are also referred to as a bonded member. Mixture of adhesives is also referred to as accidental contact. 
       FIG.  1    is a schematic perspective view of a first member  11  included in the liquid discharge head according to the present embodiment.  FIG.  2    is a schematic plan view of the first member  11  included in the liquid discharge head according to the present embodiment, corresponding to a top view in the direction of a of  FIG.  1   . 
     In the present embodiment, the first member  11  has multiple protrusions, such as a first protrusion  21  and a second protrusion  22 . The multiple protrusions each has a height corresponding to the height of the bonding region of a second member to the first member. For example, the second protrusion  22  is higher than the first protrusion  21 . In the illustrated example, the first member  11  has four corners each provided with the first protrusion  21  and has longitudinal edges each along which the second protrusion  22  is provided. Places for the first protrusion  21  and the second protrusion  22  can be appropriately selected. 
     In the example illustrated in  FIGS.  1  and  2   , the first member  11  is a frame  70  in the liquid discharge head. Preferably, the first member  11  is the frame. However, the first member  11  is not limited to the frame. Note that, although reference signs  11  and  70  are given, the first member is the frame in the present example. The frame  70  has, for example, a common channel  16  for supplying liquid to a liquid chamber. 
       FIG.  3    is a schematic side view of a bonded member in the present embodiment and illustrates the first member  11  in the direction of b of  FIG.  2   .  FIG.  4    is another schematic side view of the bonded member in the present embodiment and illustrates the first member  11  in the direction of c of  FIG.  2   . Note that the first member  11  in the present embodiment is rectangular in shape in plan view, having a longitudinal direction and a lateral direction ( FIG.  2   ).  FIG.  3    corresponds to a longitudinal side view and  FIG.  4    corresponds to a lateral side view. 
     In the example illustrated in  FIGS.  3  and  4   , a second member  12  includes an actuator substrate  53  and a support substrate  55  bonded to the actuator substrate  53 . The actuator substrate  53  includes, for example, a nozzle plate having multiple nozzles, a chamber member having a liquid chamber in communication with a nozzle, and an actuator including a piezoelectric element and an electrode. 
     The actuator substrate  53  is also referred to as a “first portion” bonded to the first protrusion  21 . 
     As illustrated in  FIG.  3   , the first member  11  has multiple protrusions protruding to the second member  12 . In the example, the multiple protrusions includes the first protrusion  21  and the second protrusion  22 . In  FIG.  3   , namely, in the longitudinal side view, two first protrusions  21  are provided on the end sides, and a second protrusion  22  is provided on the center side. 
     The multiple protrusions includes two or more types of protrusions different in height. As illustrated in  FIG.  3   , the first protrusion  21  and the second protrusion  22  are different in height. In the illustrated example, the first protrusion  21  is lower than the second protrusion  22 . 
     Note that the region between the first protrusion  21  and the second protrusion  22  is also referred to as a groove  23 . The first protrusion  21  and the second protrusion  22  are not continuous in formation. That is, the first protrusion  21  and the second protrusion  22  are intermittent in formation through the groove  23 . 
     Heights can be appropriately selected for the multiple protrusions. In the illustrated example, for example, the first protrusion  21  has a height of approximately 500 μm and the second protrusion  22  has a height of approximately 1000 μm with respect to the flat portion of the first member  11  (portion different from the protrusions). The flat portion of the first member  11  corresponds, for example, to the bottom of the groove  23 . 
     In the present embodiment, the second member  12  has a portion that bonds the multiple protrusions and varies in height depending on each protrusion. For example, as illustrated in  FIG.  3   , the second member  12  has the portion bonded to the first protrusion  21  higher in height than the portion bonded to the second protrusion  22 . 
     In the present embodiment, two or more types of adhesive are provided for bonding the first member  1 I and the second member  12  together. Use of two or more types of adhesive enables, for example, an aspect in which multiple types of adhesive different in curing rate is used for prevention of misalignment in bonding. For example, use of an epoxy adhesive and a photo-curable adhesive (e.g., an ultraviolet-curable (UV-curable) adhesive) enables prompt acquisition of a function of tentative retaining due to the photo-curable adhesive. 
     In the present embodiment, for example, a first adhesive  31  as a UV-curable adhesive is used in the bonding region of the first protrusion  21 , and a second adhesive  32  as an epoxy adhesive is used in the bonding region of the second protrusion  22 . 
     In the present embodiment, the first member  11  is provided with multiple protrusions different in height, and the second member  12  has a portion that bonds the multiple protrusions and varies in height depending on each protrusion. Thus, a bonded member based on bonding with two or more types of adhesive has the coated adhesives different in level, enabling isolation between the respective coat regions of the adhesives. Thus, the different types of adhesive are inhibited from mixing together in each bonding region. In the present embodiment, even in a case where different types of adhesive are coated in adjacent regions, the different types of adhesive are inhibited from mixing together in each bonding region. According to the present embodiment, mixture of adhesives can be inhibited in each bonding region. Thus, each adhesive can be inhibited from curing trouble, leading to acquisition of a favorable bonding state. In addition, misalignment can be inhibited in bonding. 
     In the present embodiment, the groove  23  is provided between the first protrusion  21  and the second protrusion  22 . 
     In the example illustrated in  FIG.  3   , for example, in a case where a surplus amount of first adhesive  31  or second adhesive  32  is produced at the time of bonding of the members, the surplus amount of first adhesive  31  or second adhesive  32  flows in the groove  23  between the first protrusion  21  and the second protrusion  22 , resulting in no flow to the adjacent bonding region. Thus, the different types of adhesive can be further inhibited from mixing together in each bonding region. 
     The support substrate  55  in  FIG.  3    will be supplementarily described. Referring to  FIG.  3   , the reference sign of the support substrate  55  is indicated in parentheses. The reason is that the support substrate  55  is not located between the first protrusion  21  and the second protrusion  22  but located behind the groove  23  in aside view. Thus, the groove  23  due to intermittent protrusion formation can retain an outflow of adhesive between the protrusions, so that mixture of adhesives can be further inhibited in each bonding region. 
     In the present embodiment, preferably, the same type of adhesive is used to the protrusions identical in height in the multiple protrusions, and different types of adhesive are used to the protrusions different in height in the multiple protrusions. For example, as in the present embodiment, the first adhesive  31  is used to the first protrusions  21  identical in height (two first protrusions on the end sides in the longitudinal direction). The second adhesive  32  different in type from the first adhesive  31  is used to the second protrusion  22  different in height from the first protrusion  21 . 
     Thus, the different types of adhesive can be further inhibited from mixing together in each bonding regions. 
     As described above, the first member  11  in the present embodiment is rectangular in shape in plan view, having a longitudinal direction and a lateral direction (refer to  FIG.  2   ). The multiple protrusions includes at least the first protrusion  21  and the second protrusion  22  mutually different in height. The first member  11  has four corners each provided with the first protrusion  21  and has longitudinal edges each along which the second protrusion  22  is provided. Thus, different types of adhesive can be inhibited from mixing together in each bonding region. In addition, a proper bonding region is selected between the first member  11  and the second member  12 , leading to an improvement in bonding strength. Easily achieved is an aspect in which a tentative retaining adhesive is used to the first protrusion  21 . 
     In the present embodiment, the groove  23  is provided between the first protrusion  21  and the second protrusion  22 . 
     The provided groove  23  can retain an outflow of adhesive between the protrusions, so that mixture of adhesives can be further inhibited in each bonding region. 
     As illustrated in  FIG.  4   , preferably, the first member  11  has a portion that is different from the first protrusion  21  and the second protrusion  22  and is bonded with a third adhesive  33  different from the first adhesive  31  and the second adhesive  32 . In the present embodiment, at least three types of adhesive are provided. Preferably, the first protrusion  21  is bonded with the first adhesive  31  that is photo-curable. The second protrusion  22  is bonded with the second adhesive  32  that is not photo-curable. The first member  11  has a portion that is different from the first protrusion  21  and the second protrusion  22  and is bonded with the third adhesive  33  different from the first adhesive  31  and the second adhesive  32 . 
     In this case, for example, use of a UV-curable adhesive as the first adhesive  31  that is photo-curable enables prompt acquisition of a function of tentative retaining. As the second adhesive  32  or the third adhesive  33 , an adhesive having a proper reinforcement effect can be selected, so that an improvement can be made in bonding strength. 
     In this case, for example, an epoxy adhesive is preferably used as the second adhesive  32  and an epoxy adhesive different in type from the second adhesive  32  is preferably used as the third adhesive  33 , but this is not particularly limiting. 
     An appropriate selection can be made in the thickness of adhesive. The thickness of adhesive may be constant at all the protrusions, but is preferably changed depending on each protrusion. For example, in the present embodiment, preferably, the protrusions identical in height in the multiple protrusions are identical in the thickness of adhesive, and the protrusions different in height in the multiple protrusions are different in the thickness of adhesive. Such difference in the thickness of adhesive enables further inhibition of different types of adhesive from mixing together in each bonding region. 
     In the present embodiment, at the time of bonding, the first adhesive  31  has a thickness of approximately 100 μm, the second adhesive  32  has a thickness of approximately 150 μm, and the third adhesive  33  has a thickness of approximately 50 μm. 
     The thickness of each of the first adhesive  31  and the second adhesive  32  does not necessarily require adjusting as above. Since the first member  1 I is provided with the multiple protrusions different in height, the respective gaps in the bonding regions are different (distance between the first member  11  and the second member  12 ), resulting in variations in the thickness of adhesive. In this case, the thickness of each of the first adhesive  31  and the second adhesive  32  is identical to the gap in the corresponding bonding region. 
     A thickness can be appropriately selected for the third adhesive  33 . For provision between the frame  70  and the support substrate  55 , preferably, the third adhesive  33  has a thickness having no influence on discharging performance. Such a thickness of approximately 50 μm as above is preferable because of less influence on discharging performance. 
     Entry of foreign matter between the frame  70  and the support substrate  55  in bonding causes discharge trouble. Bonding with a coat of adhesive higher in height than such foreign matter causes the foreign matter to be embedded in the adhesive, resulting in prevention of discharge trouble. Such a thickness of approximately 50 μm of the third adhesive  33  as above enables prevention of such trouble as above. 
     The liquid discharge head according to the present embodiment enables inhibition of mixture of adhesives, leading to inhibition of curing trouble. Thus, an improvement can be made in quality and an improvement can be made in discharging performance. The original adhesive capacity can be achieved because of no accidental contact of different types of adhesive, leading to inhibition of ink erosion. 
     In a case where the first member  11  and the second member  12  are used in the liquid discharge head, members to be used as the first member  11  and the second member  12  can be appropriately selected from the liquid discharge head. For example, as in the above example, preferably, the first member  11  is the frame  70  having the common channel for supplying ink to a liquid chamber, and the second member  12  includes the actuator substrate  53  and the support substrate  55  bonded to the actuator substrate  53 . The actuator substrate  53  includes, for example, a nozzle plate having multiple nozzles, a chamber member having a liquid chamber in communication with a nozzle, and an actuator including a piezoelectric element and an electrode. 
     In the present embodiment, the first member  11  and the second member  12  in the liquid discharge head are not limited to the above configuration. For example, the first member  11  may be the actuator substrate  53 , and multiple protrusions may be provided on the actuator substrate  53 . In this case, the second member  12  may be the frame  70  and may have a bonding portion varying in height depending on the height of each protrusion. From the viewpoint of member production or the viewpoint of prevention of ink entry, preferably, the first member  11  is the frame  70  and the second member  12  includes the actuator substrate  53  and the support substrate  55 . 
     The support substrate  55  is bonded to the actuator substrate  53  and has, for example, a drive region for the piezoelectric element. Note that, in  FIGS.  3  and  4   , no illustrations are given for the piezoelectric element and the drive region for the piezoelectric element. 
     The schematic side view of  FIG.  3    illustrates the electrode  52   a  in the actuator, schematically. For example, the electrode  52   a  corresponds to a region that does not face the support substrate  55  but is in contact with a wiring, as illustrated in  FIGS.  5 B and  5 C  or in  FIG.  9    to be described below. In the figure, the electrode  52   a  is indicated with broken lines. 
     The electrode  52   a  is also referred to as a “second portion” bonded to the second protrusion  22 . The electrode  52   a  (second portion) has a height different from the first portion (actuator substrate  53 ). 
     Note that the electrode  52   a  is provided ranging from one end to the other end in the direction of thickness of the actuator substrate  53  in the illustration, but this is just schematic. For example, as in  FIG.  9    to be described below, the electrode  52   a  is included in the actuator. In the present example, the electrode  52   a  includes no chamber member and no nozzle substrate. 
     Next, another example of the present embodiment will be described with  FIGS.  5 A to  5 C . 
       FIG.  5 A  is a schematic plan view of a first member  11  in the present example. Similarly to the above example, the first member  11  is a frame  70 .  FIGS.  5 B and  5 C  are schematic cross-sectional views of a bonded member in the present example.  FIG.  5 B  is a cross-sectional view taken along line A-A of  FIG.  5 A .  FIG.  5 C  is a cross-sectional view taken along line B-B of  FIG.  5 A . 
       FIG.  5 A  is substantially the same as  FIG.  2   .  FIG.  5 B  illustrates a configuration similar to the configuration in the above example. That is, the first member  11  is provided with multiple protrusions different in height (a first protrusion  21  and a second protrusion  22 ), and a second member  12  has a portion that is bonded to the multiple protrusions and varies in height depending on each protrusion. 
     The second member  12  in the present example includes an actuator substrate  53  and a support substrate  55 . A liquid discharge head  1  in the present example includes a wiring  57  through which a drive signal is supplied to a piezoelectric element. 
     In the present example, the actuator substrate  53  includes an actuator including the piezoelectric element and an electrode. The electrode  52   a  in the present example corresponds to a region that does not face the support substrate  55  but is in contact with the wiring  57 . The electrode  52   a  is bonded to a protrusion of the first member  11  (e.g., the second protrusion  22 ) through the wiring  57  and adhesive. Note that, in  FIGS.  5 A to  5 C , no reference signs are given for the actuator and the piezoelectric element. 
     A thickness can be appropriately selected for the electrode  52   a . The electrode  52   a  is thinnest in the actuator. In the present example, the electrode  52   a  has, for example, a thickness of 75 μm. 
     In the present example, as illustrated in  FIG.  5 C , the gap between the wiring  57  and the second protrusion  22  is filled with a second adhesive  32 . Thus, the strength of the electrode  52   a  thinnest in the actuator can be retained. The adhesive between the electrode  52   a  and the second protrusion  22  functions as a reinforcer, enabling retainment of the strength of the electrode  52   a . Thus, the electrode  52   a  can be prevented from being damaged. For example, during assembly with any gap not filled with the adhesive between the electrode  52   a  and the protrusion, the electrode  52   a  receives the influence of external force. Thus, the electrode  52   a  is likely to be damaged. 
     Adhesive to be provided between the electrode  52   a  and the protrusion can be appropriately selected. Preferably, an epoxy adhesive is selected. Such an adhesive functions adequately as a reinforcer, facilitating prevention of the electrode  52   a  from being damaged. 
     In the present embodiment, at least either in a cross-sectional view or in a side view, preferably, the first member  11  has a recess due to two protrusions and the second member  12  has a third protrusion that fits in the recess. In this case, a further improvement can be made in the bonding state between the first member  11  and the second member  12 . 
       FIGS.  6 A and  6 B  are explanatory views each for an exemplary recess and an exemplary third protrusion. 
       FIG.  6 A  is a schematic side view of the first member  1 I and the second member  12  not bonded together and corresponds to the schematic side view of  FIG.  4   . In the present example, the first member  11  has a recess  27  (portion indicated with a broken line in  FIG.  6 A ) due to two first protrusions  21 . In the present example, the second member  12  includes the actuator substrate  53  and the support substrate  55 , and has a third protrusion  28  (portion indicated with a broken line in  FIG.  6 A ). Then, the recess  27  and the third protrusion  28  fit mutually in bonding of the first member  11  and the second member  12 . Thus, a further improvement can be made in the bonding state between the first member  11  and the second member  12 . 
       FIG.  6 B  is a schematic cross-sectional view of the first member  11  and the second member  12  not bonded together and corresponds to, for example, in a case where line B-B of  FIG.  5 A  is further extended, a schematic cross-sectional view taken along the extended line B-B. In the present example, the first member  11  has a recess  27  (portion indicated by a broken line in  FIG.  6 B ) due to two second protrusions  22 . In the present example, the second member  12  includes the actuator substrate  53  and the support substrate  55 , and has a third protrusion  28  (portion indicated with a broken line in  FIG.  6 B ). Then, the recess  27  and the third protrusion  28  fit mutually in bonding of the first member  11  and the second member  12 . Thus, a further improvement can be made in the bonding state between the first member  11  and the second member  12 . 
     Note that two protrusions for formation of the recess  27  may be mutually identical or different in height. The protrusion of the third protrusion  28  may be formed with a member different from the support substrate  55 . 
     Next, Comparative Example 1 that is not included in the present embodiment will be described with  FIGS.  7 A to  7 C . Comparative Example 1 is similar to the present embodiment except that a frame is provided with no protrusions different in height. 
       FIG.  7 A  is a schematic plan view of a frame  71  in Comparative Example 1.  FIG.  7 B  is a schematic side view of a bonded member in Comparative Example 1 and illustrates the frame  71  in the direction of d of  FIG.  7 A .  FIG.  7 C  is a schematic cross-sectional view of the bonded member in Comparative Example 1, namely, a cross-sectional view taken along line C-C of  FIG.  7 A . 
     The frame  71  in Comparative Example 1 is provided with no protrusions different in height. The frame  71  and an actuator substrate  53  are bonded together with a first adhesive  31  and a second adhesive  32 . The frame  71  and a support substrate  55  are bonded together with a third adhesive  33 . 
     In Comparative Example 1, the base of coating of adhesive is uniform all over the frame  71 . Thus, in production of the bonded member in Comparative Example 1, all adjacent adhesives mix together. More particularly, (1) the first adhesive  31  and the second adhesive  32  mix together, (2) the first adhesive  31  and the third adhesive  33  mix together, and (3) the second adhesive  32  and the third adhesive  33  mix together. Thus, curing trouble occurs in Comparative Example 1, leading to difficulty in bonding between the frame  71  and each of the actuator substrate  53  and the support substrate  55 . 
     In Comparative Example 1, in order to avoid mixture of adjacent adhesives, the amount of coating of each adhesive was reduced. However, bonding with respective reduced amounts of coating of the adhesives caused a non-adhesion region in each bonding region. Thus, no favorable bonding state was acquired. In a liquid discharge head  1  including the acquired bonded member, leak trouble occurred. Because of inadequate sealing between the frame  71  and each of the actuator substrate  53  and the support substrate  55 , ink entry occurred. Thus, the liquid discharge head  1  did not function properly. 
     As above, the present embodiment, in which multiple protrusions different in height is provided on the first member, is effective in preventing mixture of different types of adhesive in each bonding region. 
     Next, Reference Example 1 will be described with  FIGS.  8 A to  8 C . 
       FIGS.  8 A to  8 C  correspond, respectively, to  FIGS.  5 A to  5 C .  FIG.  8 A  is a schematic plan view of a first member  11  (frame  70 ) in Reference Example 1. The first member  11  in Reference Example 1 is identical to the first member  11  in  FIG.  5 A .  FIGS.  8 B and  8 C  are schematic cross-sectional views of a bonded member in Reference Example 1.  FIG.  8 B  is a cross-sectional view taken along line D-D of  FIG.  8 A .  FIG.  8 C  is a cross-sectional view taken along line E-E of  FIG.  8 A . 
     In Reference Example 1, no second adhesive  32  is used. As illustrated in  FIG.  8 B , no second adhesive  32  is used between an actuator substrate  53  and a second protrusion  22 . As illustrated in  FIG.  8 C , no second adhesive  32  is used between a wiring  57  and a second protrusion  22 . 
     In Reference Example 1, an electrode  52   a  thinnest (e.g., a thickness of 75 μm) in an actuator is out of protection, and a gap (space) of approximately 150 μm is present between the electrode  52   a  and the second protrusion  22 . Thus, the electrode  52   a  was damaged during assembly. As a result, for reinforcement of the electrode  52   a , preferably, the gap between the electrode  52   a  and the protrusion is filled with the second adhesive as a reinforcer. 
     Next, the liquid discharge head  1  according to the present embodiment will be further described with  FIG.  9   .  FIG.  9    illustrates a liquid discharge head  1  according to the present example.  FIG.  9    is a schematic cross-sectional view of a liquid discharge head  1  according to the present example, and corresponds to, for example, in a case where line B-B of  FIG.  5 A  is further extended, a schematic cross-sectional view taken along the extended line B-B. 
     The schematic cross-sectional view in the present example illustrates no common chamber. 
     The liquid discharge head  1  according to the present example includes a frame  70 , an actuator substrate  53 , and a support substrate  55 . The frame  70  has a common channel  16  through which liquid (e.g., ink) is supplied. The liquid supplied through the common channel  16  is supplied to an individual chamber  6  through a channel. 
     The actuator substrate  53  includes, for example, a nozzle plate  50 , a chamber member  51 , and an actuator  52 . The nozzle plate  50  has multiple nozzles  4  through which liquid is discharged. The chamber member  51  has a liquid chamber (individual chamber  6 ) in communication with a nozzle. The actuator  52  includes a piezoelectric element  61  and an electrode  52   a.    
     The support substrate  55  has a drive region  62  for the piezoelectric element  61 . The support substrate  55  is bonded to the frame  70  and the actuator substrate  53 . 
     In the liquid discharge head  1  according to the present example, the piezoelectric element  61  applies pressure to the liquid inside the individual chamber  6 , so that the liquid is discharged through the nozzle  4 . 
     In the present example, the frame  70  as a first member  11  has a second protrusion  22  bonded to the actuator substrate  53  with a second adhesive  32 . The frame  70  is bonded to the support substrate  55  with a third adhesive  33 . 
     The electrode  52   a  in the present example corresponds to a region that does not face the support substrate  55  but is in contact with a wiring  57 . The electrode  52   a  is bonded to the second protrusion  22  through the wiring  57  and the second adhesive  32 . The electrode  52   a  is thinnest in thickness in the actuator  52 . The gap between the electrode  52   a  and the second protrusion  22  is filled with the second adhesive  32 . That is, the liquid discharge head  1  according to the present example has a preferable configuration. 
     Liquid Discharge Apparatus and Liquid Discharge Device 
     Next, an inkjet recording apparatus  90  is described below as an example of the liquid discharge apparatus according to the present embodiment. 
       FIGS.  10  and  11    illustrate an inkjet recording apparatus  90  according to the present example. 
     The inkjet recording apparatus  90  includes, for example, a carriage  98 , a liquid discharge head  1 , and a print mechanism  91 . The carriage  98  is movable in the scanning direction inside an apparatus body. As the liquid discharge head  1 , the liquid discharge head  1  according to the present embodiment can be used. For example, the liquid discharge head  1  is mounted on the carriage  98 . The print mechanism  91  includes, for example, an ink cartridge  99  that supplies ink to the liquid discharge head  1 . 
     The apparatus body has a lower portion to which a sheet feeding cassette  93  (or a sheet feeding tray), on which multiple sheets  92  can be loaded, is detachably attached from the front side. Provided may be a manual sheet feeding tray  94  openable for manual feeding of a sheet  92 . After import of a sheet  92  fed from the sheet feeding cassette  93  or the manual sheet feeding tray  94 , the print mechanism  91  records a required image on the sheet  92 . After that, the sheet  92  is ejected to a sheet ejection tray  95  attached to the back face side. 
     The print mechanism  91  includes a primary guide rod  96  and a secondary guide rod  97  as guide members laterally bridged between a left side plate and a right side plate, and retains the carriage  98  slidably in the main scanning direction. The liquid discharge head  1  that discharges ink droplets of respective colors of yellow (Y), cyan (C), magenta (M), and black (Bk) is attached to the carriage  98  such that multiple ink discharge ports (nozzles) is arrayed in a direction intersecting the main scanning direction with a downward direction of discharging of ink droplets. Ink cartridges  99  each for supplying ink for the corresponding color to the liquid discharge head  1  are exchangeably attached to the carriage  98 . 
     The ink cartridges  99  each have an upper portion provided with an air vent in communication with the air and a lower portion provided with a supply port for supplying ink to the liquid discharge head  1 . The ink cartridges  99  each have a porous member filled with ink, inside. Due to the capillary force of the porous member, the ink to be supplied to the liquid discharge head  1  is kept at a slight negative pressure. 
     As the liquid discharge head  1 , provided are liquid discharge heads  1  for the colors. However, provided may be a single liquid discharge head  1  having nozzles for discharging ink droplets of the colors. 
     The carriage  98  has a rear portion (on the downstream side of sheet conveyance) slidably fit to the primary guide rod  96  and a front portion (on the upstream side of sheet conveyance) slidably placed on the secondary guide rod  97 . In order to move the carriage  98  for scanning in the main scanning direction, a timing belt  104  is stretched between a drive pulley  102  that a main scanning motor  101  drives to rotate and a driven pulley  103 . The timing belt  104  is secured to the carriage  98 . Thus, the carriage  98  reciprocates due to forward and reverse rotations of the main scanning motor  101 . 
     For conveyance of a sheet  92  set in the sheet feeding cassette  93  to the lower side of the liquid discharge head  1 , the apparatus according to the present example includes a sheet feeding roller  105 , a friction pad  106 , a guide member  107 , a conveying roller  108 , and a leading rolling member  110 . 
     The sheet feeding roller  105  and the friction pad  106  separates and feeds a sheet  92  from the sheet feeding cassette  93 . The guide member  107  guides the sheet  92 . The conveying roller  108  inverts and conveys the fed sheet  92 . The leading rolling member  110  regulates the angle of delivery of the sheet  92  from a conveying rolling member  109  thrust against the circumferential face of the conveying roller  108  and the conveying roller  108 . The conveying roller  108  is driven to rotate by a sub-scanning motor through a gear train. 
     The apparatus according to the present example includes a sheet guide member  111 . The sheet guide member  111  guides, on the lower side of the liquid discharge head  1 , the sheet  92  delivered from the conveying roller  108  in accordance with the range of movement of the carriage  98  in the main scanning direction. 
     On the downstream side in the direction of sheet conveyance of the sheet guide member  111 , provided are a conveying rolling member  112  and a spur gear  113  to be driven to rotate to deliver the sheet  92  in the direction of sheet ejection. Furthermore, disposed are a sheet ejection roller  114  and a spur gear  115  that deliver the sheet  92  to the sheet ejection tray  95 , and guide members  118  and  119  forming a sheet ejection path. 
     For recording, while moving the carriage  98 , the inkjet recording apparatus  90  drives the liquid discharge head  1  in accordance with an image signal. For example, ink is discharged to the sheet  92  remaining stopped to perform recording for one line. Then, after a predetermined amount of conveyance of the sheet  92 , recording is performed for the next line. In response to reception of a recording termination signal or a signal indicating that the rear end of the sheet  92  has reached the recording region, the recording operation terminates, leading to ejection of the sheet  92 . 
     A recovery device  117  that recovers the liquid discharge head  1  from discharge trouble is disposed out of the recording region on the right end side in the direction of movement of the carriage  98 . The recovery device  117  includes a cap, a sucker, and a cleaner. The carriage  98  moves to the side of location of the recovery device  117  in order to stand for printing. Then, the liquid discharge head  1  is capped with the cap to keep a discharge port portion in a moist state, leading to prevention of discharge trouble due to ink drying. 
     For example, in the middle of recording, ink discharge not relating to the recording causes the viscosity of ink at all the discharge ports to be constant, leading to maintenance of a stable discharge state. 
     For example, in a case where discharge trouble occurs, the cap seals hermetically the discharge ports (nozzles) of the liquid discharge head  1 . Then, the sucker sucks out, for example, air bubbles together with ink from the discharge ports through a tube. Thus, the cleaner removes, for example, ink or dust having adhered to a discharge port face, resulting in recovery from the discharge trouble. The sucked ink is discharged to a waste ink container provided at the lower portion of the body and then is absorbed and retained by an ink absorber inside the waste ink container. 
     The inkjet recording apparatus  90  including the liquid discharge head  1  according to the present embodiment enables a stable ink discharging characteristic, leading to an improvement in image quality. The inkjet recording apparatus  90  including the liquid discharge head  1  has been described above. However, the liquid discharge head  1  may be applied to an apparatus that discharges non-ink liquid droplets, such as liquid resist for patterning. 
     Next, another embodiment of the liquid discharge apparatus according to the present embodiment will be described. A recording apparatus will be described below as an example of the liquid discharge apparatus according to the present embodiment. 
     The liquid discharge head according to the present embodiment can be used in various types of recording apparatuses of an inkjet recording system, such as a printer, a facsimile apparatus, a copying machine, a printer/facsimile/multifunction peripheral, a solid shaping apparatus, and a bioprinter. 
     In the present embodiment, a recording apparatus corresponds to an apparatus capable of discharging ink or various types of treatment liquids to a recording medium, and a recording method corresponds to a method for recording with the apparatus. Such a recording medium denotes an object to which ink or various types of treatment liquids can adhere temporarily. 
     The recording apparatus can include not only a head that discharges ink but also a feeder, a conveyer, and an ejector for recording media, and devices, such as a preprocessing device and postprocessing device. 
     For the recording apparatus and the recording method, provided may be a heater for use in a heat process and a dryer for use in a dry process. For example, the heater heats the printed face or back face of a recording medium. The dryer dries the printed face or back face of a recording medium. Examples of the heater and the dryer that can be used include, but are not particularly limited to, a warm air heater and an infrared heater. Heating and drying can be performed, for example, before printing, during printing, or after printing. 
     The recording apparatus and the recording method are not limited to visualization of a significant image, such as a character or a figure, with ink. For example, the recording apparatus and the recording method may be intended for formation of a pattern, such as a geometric pattern, or shaping of a three-dimensional image. Examples of the recording apparatus include, but are not particularly limited to, a serial type apparatus that moves a liquid discharge head and a line type apparatus that does not move a liquid discharge head. Examples of the recording apparatus further include a desktop recording apparatus, a wide recording apparatus capable of printing to an AO-size recording medium, and a continuous stationery printer for rolled continuous paper as a recording medium. 
     Next, another example of the liquid discharge apparatus according to the present embodiment will be described with reference to  FIGS.  12  and  13   .  FIG.  12    is an explanatory plan view of a main part of the apparatus.  FIG.  13    is an explanatory side view of the main part of the apparatus. 
     The apparatus serves as a serial type apparatus. Due to a main scanning movement mechanism  493 , a carriage  403  reciprocates in the main scanning direction. The main scanning movement mechanism  493  includes a guide member  401 , a main scanning motor  405 , and a timing belt  408 . The guide member  401  is bridged between a left side plate  491 A and a right side plate  491 B and retains the carriage  403  movably. Then, due to the main scanning motor  405 , the carriage  403  reciprocates in the main scanning direction through the timing belt  408  bridged between a drive pulley  406  and a driven pulley  407 . 
     The carriage  403  is equipped with a liquid discharge device  440  including a liquid discharge head  404  according to the present embodiment and a head tank  441 , integrally. The liquid discharge head  404  of the liquid discharge device  440  discharges liquids of colors, such as yellow (Y), cyan (C), magenta (M), and black (K). The liquid discharge head  404  is attached such that a nozzle array of multiple nozzles  4  is disposed in the sub-scanning direction orthogonal to the main scanning direction with a downward direction of discharging. 
     A supply mechanism  494  that supplies the liquid discharge head  404  with liquid stored outside the liquid discharge head  404  supplies the head tank  441  with liquid stored in a liquid cartridge  450 . 
     The supply mechanism  494  includes a cartridge holder  451  as a holder to which the liquid cartridge  450  is attached, a tube  456 , and a liquid feeding unit  452  including a liquid feeding pump. The liquid cartridge  450  is detachably attached to the cartridge holder  451 . The liquid feeding unit  452  feeds the liquid from the liquid cartridge  450  to the head tank  441  through the tube  456 . 
     The apparatus includes a conveyance mechanism  495  that conveys a sheet  410 . The conveyance mechanism  495  includes a conveying belt  412  as a conveyor and a sub-scanning motor  416  that drives the conveying belt  412 . 
     The conveying belt  412  attracts and conveys the sheet  410  such that the sheet  410  faces the liquid discharge head  404 . The conveying belt  412  serves as an endless belt stretched between a conveying roller  413  and a tension roller  414 . Such attraction as above can be achieved by electrostatic attraction or air suction. 
     Then, through a timing belt  417  and a timing pulley  418 , the sub-scanning motor  416  drives the conveying roller  413  to rotate, so that the conveying belt  412  runs circumferentially in the sub-scanning direction. 
     Furthermore, on the lateral side of the conveying belt  412  on one side in the main scanning direction of the carriage  403 , disposed is a maintenance mechanism  420  that maintains the liquid discharge head  404 . 
     The maintenance mechanism  420  includes, for example, a cap member  421  that caps the nozzle face of the liquid discharge head  404  (face on which the nozzles  4  are formed) and a wiper member  422  that wipes the nozzle face. 
     The main scanning movement mechanism  493 , the supply mechanism  494 , the maintenance mechanism  420 , and the conveyance mechanism  495  are attached to a housing including the left side plate  491 A, the right side plate  491 B, and a rear plate  491 C. 
     In the apparatus having such a configuration as above, the sheet  410  is fed on and attracted to the conveying belt  412 . Then, the sheet  410  is conveyed in the sub-scanning direction due to a circumferential run of the conveying belt  412 . 
     Then, with the carriage  403  moving in the main scanning direction, the liquid discharge head  404  is driven, in accordance with an image signal, to discharge liquid to the sheet  410  remaining stopped, leading to formation of an image. 
     As above, the apparatus including the liquid discharge head according to the present embodiment enables stable formation of a high-quality image. 
     Next, another example of the liquid discharge device according to the present embodiment will be described with reference to  FIG.  14   . 
       FIG.  14    is an explanatory plan view of a main part of the liquid discharge device. 
     The liquid discharge device includes the housing including the left side plate  491 A, the right side plate  491 B, and the rear plate  491 C, the main scanning movement mechanism  493 , the carriage  403 , and the liquid discharge head  404 , from among the constituent members of the liquid discharge apparatus described above. 
     Note that, for example, the liquid discharge device may have the right side plate  491 B to which at least either the maintenance mechanism  420  or supply mechanism  494  described above is attached. 
     Next, still another example of the liquid discharge device according to the present embodiment will be described with reference to  FIG.  15   .  FIG.  15    is an explanatory front view of the liquid discharge device. 
     The liquid discharge device includes a liquid discharge head  404  to which a channel component  444  is attached, and a tube  456  connected to the channel component  444 . 
     Note that the channel component  444  is disposed inside a cover  442 . Instead of the channel component  444 , a head tank  441  can be provided. The channel component  444  has an upper portion provided with a connector  443  for electrical connection with the liquid discharge head  404 . 
     In the present specification, the “liquid discharge apparatus” includes a liquid discharge head or a liquid discharge device and drives the liquid discharge head to discharge liquid. Examples of the liquid discharge apparatus include an apparatus capable of discharging liquid to an object to which liquid can adhere and an apparatus that discharges liquid into gas or liquid. 
     The “liquid discharge apparatus” can include a feeder, a conveyer, and an ejector for an object to which liquid can adhere, a preprocessing device, and a postprocessing device. 
     Examples of the “liquid discharge apparatus” include an image forming apparatus that discharges ink to a sheet to form an image on the sheet, and a solid shaping apparatus (three-dimensionally shaping apparatus) that discharges shaping liquid to a powder-conglomeration layer as a layered conglomeration of powder in order to shape a solid shaped object (three-dimensionally shaped object). 
     The “liquid discharge apparatus” is not limited to visualization of a significant image, such as a character or a figure, with discharged liquid. For example, the liquid discharge apparatus may be intended for formation of a meaningless pattern or shaping of a three-dimensional image. 
     The “object to which liquid can adhere” denotes an object to which liquid can adhere at least temporarily, an object on which liquid fastens after adhering to, and an object into which liquid permeates after adhering to. Specific examples of the “object to which liquid can adhere” include a recording medium, such as a sheet, recording paper, a recording sheet, a film, or cloth, an electronic component, such as an electronic circuit board or a piezoelectric element, and a medium, such as a powder-conglomeration layer (powder layer), an organ model, or a testing cell. Unless otherwise particularly limited, the “object to which liquid can adhere” may be any object to which liquid adheres. 
     Examples of the material of the “object to which liquid can adhere” include paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramic, building materials, such as wallpaper and flooring, and a textile for clothing that enable temporary adhesion of liquid. 
     Examples of the “liquid” include ink, treatment liquid, a deoxyribonucleic acid (DNA) sample, resist, pattern material, a binder, shaping liquid, and a solution or dispersion liquid containing an amino acid, protein, or calcium. 
     The “liquid discharge apparatus” may be, but is not limited to, an apparatus that moves relatively a liquid discharge head and an object to which liquid can adhere. Specific examples of the “liquid discharge apparatus” include a serial type apparatus that moves a liquid discharge head and a line type apparatus that does not move a liquid discharge head. 
     Examples of the “liquid discharge apparatus” further include a treatment-liquid coating apparatus that discharges, for the purpose of reforming the surface of a sheet, treatment liquid to the sheet to coat the treatment liquid on the surface of the sheet, and a jet granulation apparatus that jets a composition liquid including row material dispersed in a solution, through a nozzle to granulate fine particles of the row material. 
     The “liquid discharge device” corresponds to an integration of a liquid discharge head and a functional component or mechanism, namely, an assembly of components relating to liquid discharge. Examples of the “liquid discharge device” include a combination of a liquid discharge head with at least one of a head tank, a carriage, a supply mechanism, a maintenance mechanism, or a main scanning movement mechanism. 
     Examples of such an integration as above include a combination of a liquid discharge head and a functional component or mechanism secured together, for example, by fastening, bonding, or engaging, and a combination of a liquid discharge head and a functional component or mechanism, in which one of the liquid discharge head and the functional component or mechanism is retained movably to the other. A liquid discharge head and a functional component or mechanism may be detachably attachable to each other. 
     Like the liquid discharge device  440  illustrated in  FIG.  13   , for example, a liquid discharge head and a head tank are integrated together as a liquid discharge device. For example, a liquid discharge head and a head tank mutually connected through a tube are integrated together as a liquid discharge device. Such a liquid discharge device can have a unit including a filter between the head tank and the liquid discharge head. 
     For example, a liquid discharge head and a carriage are integrated together as a liquid discharge device. 
     For example, a liquid discharge head and a main scanning movement mechanism are integrated together as a liquid discharge device, with the liquid discharge head retained movably by a guide member as part of the main scanning movement mechanism. For example, as such a liquid discharge device as illustrated in  FIG.  14   , a liquid discharge head, a carriage, and a main scanning movement mechanism are integrated together. 
     For example, a liquid discharge head, a carriage, and a maintenance mechanism are integrated together as a liquid discharge device, in which a cap member as part of the maintenance mechanism is secured to the carriage to which the liquid discharge head is attached. 
     For example, as such a liquid discharge device as illustrated in  FIG.  15   , a liquid discharge head and a supply mechanism are integrated together, with a tube connected to the liquid discharge head to which a head tank or a channel component is attached. 
     Such a main scanning movement mechanism as above includes a guide member as a single item. Such a supply mechanism as above includes a tube as a single item and a holder as a single item. 
     The “liquid discharge head” is not limited in terms of a pressure generator to be used. For example, instead of such a piezoelectric actuator as described in the above embodiment (or a multilayered piezoelectric element), used may be a thermal actuator employing a thermoelectric conversion element, such as a heat-generating resistor, or an electrostatic actuator including a vibration membrane and opposed electrodes. 
     According to the present embodiment, provided can be a liquid discharge head including a bonded member based on bonding with two or more types of adhesive, with inhibition of mixture of different types of adhesive in each bonding region. 
     In the present specification, the terms “image forming”, “recording”, “printing”, “image printing”. “print”, and “shaping” are synonymous. 
     [Aspect 1] 
     A liquid discharge head ( 1 ) includes: a first member ( 11 ): and a second member ( 12 ) bonded to the first member ( 11 ). The first member ( 11 ) has: a first protrusion ( 21 ) protruding to the second member ( 12 ), a second protrusion ( 22 ) protruding to the second member ( 12 ), the second protrusion having a height different from the first protrusion, the second member ( 12 ) includes: a first portion ( 53 ) bonded to the first protrusion ( 21 ) with a first adhesive ( 31 ); and a second portion ( 52   a ) bonded to the second protrusion ( 22 ) with a second adhesive ( 32 ), the second portion ( 52   a ) having a height different from the first portion ( 53 ), and, a type of the second adhesive ( 32 ) is different from a type of the first adhesive ( 31 ). 
     [Aspect 2] 
     In the liquid discharge head ( 1 ) according to Aspect 1, the first protrusion ( 21 ) has multiple first protrusions ( 21 ) having the same height, the first adhesive ( 31 ) is applied to each of the multiple first protrusions ( 21 ), the second protrusion ( 22 ) has multiple second protrusions ( 22 ) having the same height, the second adhesive ( 32 ) is applied to each of the multiple second protrusions ( 22 ) having the same height. 
     [Aspect 3] 
     In the liquid discharge head ( 1 ) according to Aspect 2, the first member ( 11 ) has a rectangular shape elongated in a longitudinal direction, the first member ( 11 ) has the multiple first protrusions ( 21 ) disposed at four corners of the first member ( 11 ), and the first member ( 11 ) has the multiple second protrusion ( 22 ) on each end of the first member ( 11 ) in a transverse direction orthogonal to the longitudinal direction. 
     [Aspect 4] 
     In the liquid discharge head ( 1 ) according to Aspect 3, further includes a third adhesive ( 33 ), a type of which is different from the type of the first adhesive ( 31 ) and the type of the second adhesive ( 32 ), the first adhesive ( 31 ) is photo-curable, the second adhesive ( 32 ) is not photo-curable, the first member ( 11 ) further includes a third portion other than the first protrusion ( 21 ) and the second protrusion ( 22 ), and the third adhesive ( 33 ) is applied to the third portion. 
     [Aspect 5] 
     In the liquid discharge head ( 1 ) according to Aspect 2, wherein the first adhesive ( 31 ) applied to each of the multiple first protrusions ( 21 ) has the same thickness, the second adhesive ( 32 ) applied to each of the multiple second protrusions ( 22 ) has the same thickness, and a thickness of the first adhesive ( 31 ) and a thickness of the second adhesive ( 32 ) are different. 
     [Aspect 6] 
     In the liquid discharge head ( 1 ) according to Aspect 1, the first member ( 11 ) includes a common channel ( 16 ) having liquid; the second member ( 12 ) includes, an actuator substrate ( 53 ); and a support substrate ( 55 ) bonded to the actuator substrate ( 53 ), and the actuator substrate ( 53 ) includes: a nozzle plate ( 50 ) having multiple nozzles ( 4 ); a chamber member ( 51 ) including multiple individual chambers ( 6 ) respectively communicating with the multiple nozzles ( 4 ), and communicating with the common channel ( 16 ) of the first member; and an actuator ( 52 ) including a piezoelectric element ( 61 ) and an electrode ( 52   a ) connected to the piezoelectric element ( 61 ), the piezoelectric element ( 61 ) is configured to discharge the liquid in the multiple individual chambers ( 6 ) from the multiple nozzles ( 4 ). 
     [Aspect 7] 
     In the liquid discharge head ( 1 ) according to Aspect 6, further includes a wiring ( 57 ) contacting the electrode ( 52   a ), The electrode ( 52   a ) is bonded to the second protrusion ( 22 ) via the wiring ( 57 ) and the second adhesive ( 32 ), the electrode ( 52   a ) has a thickness thinnest in the actuator ( 52 ), and the second adhesive ( 32 ) fills a gap between the wiring ( 57 ) and the second protrusion ( 22 ). 
     [Aspect 8] 
     In the liquid discharge head ( 1 ) according to Aspect 1, the first member ( 11 ) has a recess ( 27 ) defined by two of the multiple second protrusions ( 22 ), and the second member ( 12 ) has a third protrusion ( 28 ) fitting into the recess ( 27 ). 
     [Aspect 9] 
     In the liquid discharge head ( 1 ) according to Aspect 1, the first member ( 11 ) has a groove ( 23 ) between the first protrusion ( 21 ) and the second protrusion ( 22 ). 
     [Aspect 10] 
     In a liquid discharge device ( 440 ) comprising the liquid discharge head ( 1 ) according to claim  1 . 
     [Aspect 11] 
     In the liquid discharge device ( 440 ) according to Aspect 10, further comprising at least one of: a head tank ( 441 ) storing a liquid to be supplied to the liquid discharge head ( 1 ); a carriage ( 403 ) on which the liquid discharge head ( 1 ) is mounted; a supply mechanism ( 494 ) configured to supply the liquid to the liquid discharge head ( 1 ); a maintenance mechanism ( 420 ) configured to maintain the liquid discharge head ( 1 ); or a main scanning movement mechanism ( 493 ) configured to move the liquid discharge head ( 1 ) in a main scanning direction, combined together with the liquid discharge head ( 1 ) to form a single body. 
     [Aspect 12] 
     A liquid discharge apparatus ( 90 ) includes the liquid discharge device ( 440 ) according to claim  10 . 
     The above-described embodiments are illustrative and do not limit the present invention. Thus, numerous additional modifications and variations are possible in light of the above teachings. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of the present invention.