Liquid ejection head and liquid ejection apparatus

Abstract

The invention provides a liquid ejecting head and a liquid ejecting apparatus. The liquid ejection head includes: a pressure chamber substrate provided with a first pressure chamber and a second pressure chamber extending in a first direction; a plurality of piezoelectric elements disposed on the upper portion of the pressure chamber substrate and including a piezoelectric body; and a sealing plate provided with a first recess and a second recess, the sealing plate being disposed above the plurality of piezoelectric bodies, the first recess housing a first piezoelectric element corresponding to the first pressure chamber, the second recess housing a second piezoelectric element corresponding to the second pressure chamber, and the second pressure chamber housing a second piezoelectric element corresponding to the second pressure chamber. The piezoelectric body has a first region that overlaps the first pressure chamber, a second region that overlaps a wall of the first recess, a third region that overlaps the second pressure chamber, and a fourth region that overlaps a wall of the second recess, and the first region is provided between the second region and the third region and is separated from the second region. The third region is located between the first region and the fourth region and is separated from the fourth region.

Description

Technical Field

[0001] The present invention relates to a liquid ejecting head and a liquid ejecting device. Background Art

[0002] Liquid ejection heads for ejecting liquids such as ink are widely known. For example, Patent Document 1 discloses a liquid ejection head comprising: a piezoelectric element comprising a piezoelectric body, an upper electrode, and a lower electrode; a pressure chamber whose internal pressure increases and decreases as the piezoelectric element is driven; a sealing plate having a recess for accommodating the piezoelectric element; and a nozzle that ejects liquid within the pressure chamber as the pressure within the pressure chamber increases.

[0003] However, in conventional technology, when viewing the liquid ejection head from above, the piezoelectric element is arranged so that, in addition to the area overlapping with the pressure chamber, it also extends broadly from the area overlapping with one wall of the recess provided on the sealing plate to the area overlapping with the other wall of the recess. Therefore, according to conventional technology, vibrations generated by driving the piezoelectric element are transmitted through the piezoelectric element to both walls of the recess, potentially changing the relative position between the sealing plate and the piezoelectric element, or changing the relative position between the pressure chamber substrate on which the pressure chamber is formed and the piezoelectric element.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-020407 Summary of the Invention

[0005] In order to solve the above problems, the liquid ejection head according to the present invention is characterized by including: a pressure chamber substrate provided with a plurality of pressure chambers including a first pressure chamber and a second pressure chamber, wherein the first pressure chamber extends in a first direction, and the second pressure chamber is provided at a position different from that of the first pressure chamber in the first direction and extends in the first direction; a plurality of piezoelectric elements arranged on the upper part of the pressure chamber substrate and including a piezoelectric body, an upper electrode, and a lower electrode; a sealing plate provided with a first recess and a second recess and arranged on the upper part of the plurality of piezoelectric elements, wherein the first recess houses a first piezoelectric element corresponding to the first pressure chamber among the plurality of piezoelectric elements, the second recess houses a second piezoelectric element corresponding to the second pressure chamber among the plurality of piezoelectric elements, and when the liquid ejection head is viewed from above with respect to the vertical direction, the piezoelectric body has: a first region overlapping with the first pressure chamber; a second region overlapping with one of the two walls of the first recess in the first direction; a third region overlapping with the second pressure chamber; a fourth region overlapping with one of the two walls of the second recess in the first direction, the first region is located between the second region and the third region in the first direction and is arranged in a manner separated from the second region, and the third region is located between the first region and the fourth region in the first direction and is arranged in a manner separated from the fourth region.

[0006] In addition, the liquid ejection device according to the present invention is characterized in that it includes a liquid ejection head, and the liquid ejection head includes: a pressure chamber substrate provided with a plurality of pressure chambers including a first pressure chamber and a second pressure chamber, wherein the first pressure chamber extends in a first direction, and the second pressure chamber is provided at a position different from the first pressure chamber in the first direction and extends in the first direction; a plurality of piezoelectric elements arranged on the upper part of the pressure chamber substrate and including a piezoelectric body, an upper electrode, and a lower electrode; a sealing plate provided with a first recess and a second recess and arranged on the upper part of the plurality of piezoelectric elements, wherein the first recess houses a first piezoelectric element corresponding to the first pressure chamber among the plurality of piezoelectric elements, and the second recess houses a second piezoelectric element corresponding to the second pressure chamber among the plurality of piezoelectric elements. When the liquid ejection head is viewed from above with respect to the vertical direction, the piezoelectric body has: a first region overlapping with the first pressure chamber; a second region overlapping with one of the two walls of the first recess in the first direction; a third region overlapping with the second pressure chamber; a fourth region overlapping with one of the two walls of the second recess in the first direction. The first region is located between the second region and the third region in the first direction and is arranged so as to be separated from the second region, and the third region is located between the first region and the fourth region in the first direction and is arranged so as to be separated from the fourth region. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 FIG. is a structural diagram showing an example of a liquid ejection device 100 according to a first embodiment of the present invention.

[0008] Figure 2 FIG. is an exploded perspective view showing an example of the structure of the liquid ejection head 1.

[0009] Figure 3 FIG. is a cross-sectional view showing an example of the structure of the liquid ejection head 1.

[0010] Figure 4 FIG. is a cross-sectional view showing an example of the structure of the liquid ejection head 1.

[0011] Figure 5 FIG. is a cross-sectional view showing an example of the structure of the liquid ejection head 1.

[0012] Figure 6 FIG. is a top view showing an example of the structure of the actuator substrate AT.

[0013] Figure 7A plan view showing an example of the structure of the pressure chamber substrate 23.

[0014] Figure 8 A cross-sectional view showing an example of the structure of the liquid ejection head 1Z according to Reference Example 1.

[0015] Figure 9 A plan view showing an example of the structure of the actuator substrate AT-Z according to Reference Example 1.

[0016] Figure 10 A cross-sectional view showing an example of the structure of the liquid ejection head 1W according to Reference Example 2.

[0017] Figure 11 A plan view showing an example of the structure of the actuator substrate AT-W according to Reference Example 2.

[0018] Figure 12 A cross-sectional view showing an example of the structure of the liquid ejection head 1B according to the second embodiment of the present invention.

[0019] Figure 13 A plan view showing an example of the structure of the actuator substrate AT-B.

[0020] Figure 14 A cross-sectional view showing an example of the structure of the liquid ejection head 1C according to Modification 1 of the present invention. Detailed Description of the Invention

[0021] Hereinafter, modes for implementing the present invention will be described with reference to the drawings. However, in each of the drawings, the dimensions and scales of the respective parts are appropriately different from the actual situation. In addition, since the embodiments described below are preferred specific examples of the present invention, various technically preferred limitations are given. However, as long as there is no description specifically limiting the meaning of the present invention in the following description, the scope of the present invention is not limited to these modes.

[0022] A. First Embodiment

[0023] Hereinafter, the liquid ejection device 100 according to the first embodiment will be described.

[0024] A.1. Outline of the Liquid Ejection Device

[0025] Figure 1 An explanatory diagram showing the liquid ejection device 100 according to the first embodiment.

[0026] The liquid ejection device 100 is an inkjet printing device that ejects ink onto a medium PP. Although the medium PP is typically printing paper, any printing object such as a resin film or cloth can be used as the medium PP.

[0027] As Figure 1 shown, the liquid ejection device 100 includes a plurality of liquid ejection heads 1, a control device 8, a conveyance mechanism 91, a moving mechanism 92, and a liquid container 93.

[0028] The liquid container 93 stores the ink and supplies the stored ink to the liquid ejection heads 1. As the liquid container 93, for example, a cartridge that can be detachably attached to the liquid ejection device 100, a bag-shaped ink pack formed of a flexible film, or an ink tank that can replenish ink can be used. In the liquid container 93, a plurality of inks of different colors are stored.

[0029] In addition, the ink is an example of a "liquid".

[0030] The control device 8 includes, for example, a processing circuit such as a CPU or an FPGA, and a storage circuit such as a semiconductor memory, and controls each element of the liquid ejection device 100. Here, CPU is an abbreviation for Central Processing Unit, and FPGA is an abbreviation for Field Programmable Gate Array.

[0031] The conveyance mechanism 91 conveys the medium PP in the Y1 direction along the Y axis under the control performed by the control device 8. Hereinafter, the Y1 direction and the Y2 direction opposite to the Y1 direction are collectively referred to as the Y-axis direction. In addition, hereinafter, the X1 direction along the X axis intersecting the Y axis and the X2 direction opposite to the X1 direction are collectively referred to as the X-axis direction. In addition, hereinafter, the Z1 direction along the Z axis intersecting the X axis and the Y axis and the Z2 direction opposite to the Z1 direction (an example of the "upward direction") are collectively referred to as the Z-axis direction (an example of the "vertical direction"). In the first embodiment, as an example, a case where the X axis, the Y axis, and the Z axis are orthogonal to each other is assumed for description. However, the present invention is not limited to such a manner. The X axis, the Y axis, and the Z axis only need to intersect each other.

[0032] The moving mechanism 92 reciprocally moves the plurality of liquid ejection heads 1 in the X1 direction and the X2 direction under the control performed by the control device 8. The moving mechanism 92 includes a housing 921 that houses the plurality of liquid ejection heads 1, and an endless belt 922 to which the housing 921 is fixed. In addition, the liquid container 93 may be housed in the housing 921 together with the liquid ejection heads 1.

[0033] The control device 8 supplies a drive signal Com for driving the liquid ejection head 1 and a control signal SI for controlling the liquid ejection head 1 to the liquid ejection head 1. Further, the liquid ejection head 1 is driven by the drive signal Com under the control implemented by the control signal SI so that ink is ejected from a part or all of a plurality of nozzles N provided on the liquid ejection head 1 in the Z1 direction. That is, the liquid ejection head 1 ejects ink from a part or all of the plurality of nozzles N in a manner linked to the conveyance of the medium PP performed by the conveyance mechanism 91 and the reciprocating movement of the liquid ejection head 1 performed by the moving mechanism 92, and causes the ejected ink to be ejected onto the surface of the medium PP, thereby forming a desired image on the surface of the medium PP. In addition, regarding the nozzle N, it will be described later with reference to Figure 2 and Figure 3 and will be described later.

[0034] A.2. Outline of liquid ejection head

[0035] Hereinafter, with reference to Figure 2 and Figure 3 the outline of the liquid ejection head 1 will be described.

[0036] Figure 2 is an exploded perspective view of the liquid ejection head 1, Figure 3 is Figure 2 a cross-sectional view taken along line III-III in

[0037] As shown in Figure 2 and Figure 3 the liquid ejection head 1 includes a nozzle substrate 21, plastic sheets CS1 and CS2, a communication board 22, a pressure chamber substrate 23, a diaphragm 24, a sealing substrate 25, a flow path forming substrate 26, and a piezoelectric structure 27 including a piezoelectric element PZ. In addition, hereinafter, the structure including the diaphragm 24 and the piezoelectric structure 27 will be referred to as an actuator substrate AT. Further, hereinafter, the structure including the actuator substrate AT, the sealing substrate 25, and the pressure chamber substrate 23 will be referred to as an actuator chip AC.

[0038] As shown in Figure 2 the nozzle substrate 21 is a plate-like member that is long and narrow in the Y-axis direction and extends substantially parallel to the XY plane. Although in the first embodiment, it is assumed that the nozzle substrate 21 is manufactured by processing a single crystal substrate of silicon using semiconductor manufacturing techniques such as etching, any known material and manufacturing method can be arbitrarily adopted for manufacturing the nozzle substrate 21.

[0039] In addition, in this specification, "substantially parallel" means a concept that includes cases where, in addition to the case of being completely parallel, it is considered parallel when considering errors. Specifically, "substantially parallel" means a concept that includes cases where it is considered parallel when considering an error of about 10%. In addition, in this specification, expressions such as "substantially the same" also have the same meaning as "substantially parallel", which means that it is considered "the same" when considering errors.

[0040] A plurality of nozzles N are formed on the nozzle substrate 21. Here, the nozzle N refers to a through hole provided on the nozzle substrate 21. In the first embodiment, it is assumed that the plurality of nozzles N formed on the nozzle substrate 21 include a plurality of nozzles N1 and a plurality of nozzles N2, wherein the plurality of nozzles N1 are arranged and configured to extend in the Y-axis direction, and when observing from the plurality of nozzles N1, the plurality of nozzles N2 are arranged and configured to extend in the Y-axis direction at positions in the X2 direction. Hereinafter, the plurality of nozzles N1 extending in the Y-axis direction are referred to as a nozzle row Ln1, and the plurality of nozzles N2 extending in the Y-axis direction are referred to as a nozzle row Ln2. In addition, hereinafter, the nozzle row Ln1 and the nozzle row Ln2 may be collectively referred to as a nozzle row Ln.

[0041] In addition, in the first embodiment, it is assumed that the structural elements corresponding to the nozzle row Ln1 and the structural elements corresponding to the nozzle row Ln2 in the liquid ejection head 1 are substantially symmetrically formed with a plane having the X-axis direction as the normal direction as the symmetry plane. Therefore, hereinafter, the structural elements corresponding to the nozzle row Ln1 in the liquid ejection head 1 will be mainly described, and the description of the structural elements corresponding to the nozzle row Ln2 will be appropriately omitted.

[0042] As Figure 2 and Figure 3 shown, when observing from the nozzle substrate 21, a communication plate 22 is provided at a position (upper part) in the Z2 direction. The communication plate 22 is a plate-shaped member that is long and narrow in the Y-axis direction and extends substantially parallel to the XY plane. Although in the first embodiment, it is assumed that the communication plate 22 is manufactured by processing a single crystal substrate of silicon using semiconductor manufacturing technology, any known material and manufacturing method can be arbitrarily adopted for the manufacturing of the communication plate 22.

[0043] An ink flow path is formed on the connection plate 22. Specifically, on the connection plate 22, a supply flow path BA1 is formed corresponding to the nozzle row Ln1 and is arranged to extend in the Y-axis direction. In addition, on the connection plate 22, a plurality of connection flow paths BK1 corresponding to the plurality of nozzles N1 and a plurality of communication flow paths BR1 corresponding to the plurality of nozzles N1 are formed corresponding to the nozzle row Ln1. The connection flow path BK1 communicates with the supply flow path BA1 and is arranged to extend in the Z-axis direction at a position in the X2 direction when viewed from the supply flow path BA1. The communication flow path BR1 is arranged to extend in the Z-axis direction at a position in the X2 direction when viewed from the connection flow path BK1. The communication flow path BR1 communicates with the nozzle N1 corresponding to the communication flow path BR1.

[0044] In addition, on the connection plate 22, a supply flow path BA2, which is an element symmetric to the supply flow path BA1, a plurality of connection flow paths BK2, which are elements symmetric to the plurality of connection flow paths BK1, and a plurality of communication flow paths BR2, which are elements symmetric to the plurality of communication flow paths BR1, are formed corresponding to the nozzle row Ln2. Hereinafter, the supply flow path BA1 and the supply flow path BA2 may be collectively referred to as the supply flow path BA, the connection flow paths BK1 and BK2 may be collectively referred to as the connection flow path BK, and the communication flow paths BR1 and BR2 may be collectively referred to as the communication flow path BR.

[0045] As Figure 2 and Figure 3 shown, when viewed from the connection plate 22, a pressure chamber substrate 23 is arranged at a position in the Z2 direction. The pressure chamber substrate 23 is a plate-shaped member that is long and narrow in the Y-axis direction and extends substantially parallel to the XY plane. Although in the first embodiment it is assumed that the pressure chamber substrate 23 is manufactured by processing a single crystal substrate of silicon using semiconductor manufacturing technology, for the manufacture of the pressure chamber substrate 23, known materials and manufacturing methods can also be arbitrarily adopted.

[0046] An ink flow path is formed on the pressure chamber substrate 23. Specifically, on the pressure chamber substrate 23, a plurality of pressure chambers CV1 corresponding to the plurality of nozzles N1, a plurality of communication flow paths BC1 corresponding to the plurality of nozzles N1 (omitted in Figure 2 ), and a plurality of communication flow paths BD1 corresponding to the plurality of nozzles N1 (omitted in Figure 2 ) are formed corresponding to the nozzle row Ln1. As Figure 3As shown, the communication flow path BC1 communicates with the connection flow path BK1, and is arranged to extend in the X-axis direction at a position in the Z2 direction when observed from the connection flow path BK1. The communication flow path BD1 communicates with the communication flow path BC1, and is arranged to extend in the X-axis direction at a position in the X2 direction when observed from the communication flow path BC1. The pressure chamber CV1 connects the end portion in the X2 direction of the communication flow path BD1 and the end portion in the X1 direction of the communication flow path BR1, and is arranged to extend in the X-axis direction.

[0047] In addition, on the pressure chamber substrate 23, a plurality of pressure chambers CV2, which are elements symmetric to the plurality of pressure chambers CV1, a plurality of communication flow paths BC2, which are elements symmetric to the plurality of communication flow paths BC1, and a plurality of communication flow paths BD2, which are elements symmetric to the plurality of communication flow paths BD1, are formed corresponding to the nozzle row Ln2. Hereinafter, the pressure chambers CV1 and CV2 may be collectively referred to as the pressure chamber CV, the communication flow paths BC1 and BC2 may be collectively referred to as the communication flow path BC, and the communication flow paths BD1 and BD2 may be collectively referred to as the communication flow path BD.

[0048] As Figure 2 and Figure 3 shown, when observed from the pressure chamber substrate 23, a diaphragm 24 is provided at a position in the Z2 direction. The diaphragm 24 is a plate-like member that is long and narrow in the Y-axis direction and extends substantially parallel to the XY plane, and is a member that can vibrate elastically.

[0049] As Figure 2 and Figure 3 shown, when observed from the diaphragm 24, a plurality of piezoelectric elements PZ1 corresponding to the plurality of pressure chambers CV1 are provided at a position in the Z2 direction corresponding to the nozzle row Ln1. The piezoelectric element PZ1 is a driving element that deforms according to the potential change of the driving signal Com. In other words, the piezoelectric element PZ1 is an example of an energy conversion element that converts the electrical energy of the driving signal Com into kinetic energy. Specifically, the piezoelectric element PZ1 is driven according to the potential change of the driving signal Com, and then deforms. The diaphragm 24 vibrates in a manner linked to the deformation of the piezoelectric element PZ1, and the pressure in the pressure chamber CV1 changes due to this vibration. Moreover, due to the change in the pressure in the pressure chamber CV1, the ink filled inside the pressure chamber CV1 is ejected from the nozzle N1 via the communication flow path BR1.

[0050] Further, when viewed from the vibration plate 24, at a position in the Z2 direction, a plurality of piezoelectric elements PZ2, which are elements symmetric to the plurality of piezoelectric elements PZ1, are provided corresponding to the nozzle row Ln2. Hereinafter, the piezoelectric elements PZ1 and the piezoelectric elements PZ2 may be collectively referred to as the piezoelectric element PZ.

[0051] As Figure 2 and Figure 3 shown, when viewed from the vibration plate 24, at a position in the Z2 direction, a sealing substrate 25 for protecting the plurality of piezoelectric elements PZ is provided. The sealing substrate 25 is a plate-shaped member that is long and narrow in the Y-axis direction and extends substantially parallel to the XY plane. Although in the first embodiment it is assumed that the sealing substrate 25 is manufactured by processing a single-crystal substrate of silicon using semiconductor manufacturing technology, for the manufacture of the sealing substrate 25, known materials and manufacturing methods can be arbitrarily adopted.

[0052] As Figure 2 and Figure 3 shown, on the surface in the Z1 direction among the two surfaces of the sealing substrate 25 having the Z-axis direction as the normal direction, an OB1 that defines a sealing space SP1 for accommodating the plurality of piezoelectric elements PZ1 is provided corresponding to the nozzle row Ln1. The sealing space SP1 is a space for sealing the piezoelectric element PZ1 and preventing the piezoelectric element PZ1 from deteriorating due to the influence of moisture or the like. Hereinafter, when the sealing substrate 25 is viewed from above in the Z1 direction, the wall located in the X2 direction among the two walls of the recess OB1 in the X-axis direction is referred to as the wall WA1, and the wall located in the X1 direction is referred to as the wall WB1.

[0053] Further, on the sealing substrate 25, a recess OB2 is provided corresponding to the nozzle row Ln2. The recess OB2 has a wall WA2 that is an element symmetric to the wall WA1 and a wall WB2 that is an element symmetric to the wall WB1, and defines a sealing space SP2 that is an element symmetric to the sealing space SP1. Hereinafter, the sealing space SP1 and the sealing space SP2 may be collectively referred to as the sealing space SP, the recess OB1 and the recess OB2 may be collectively referred to as the recess OB, the wall WA1 and the wall WA2 may be collectively referred to as the wall WA, and the wall WB1 and the wall WB2 may be collectively referred to as the wall WB.

[0054] In addition, a through-hole 250 is provided on the sealing substrate 25. The through-hole 250 is a hole that is located between the sealing space SP1 and the sealing space SP2 when the sealing substrate 25 is viewed in the Z1 direction and penetrates from the surface in the Z1 direction of the sealing substrate 25 to the surface in the Z2 direction of the sealing substrate 25. A wiring substrate 4 is inserted through the through-hole 250.

[0055] AsFigure 2 and Figure 3 As shown in Figure 3 , when viewed from the connection board 22, a flow path forming substrate 26 is provided at a position in the Z2 direction. The flow path forming substrate 26 is a plate-shaped member that is long and narrow in the Y-axis direction and extends substantially parallel to the XY plane. Although it is assumed in the first embodiment that the flow path forming substrate 26 is formed by injection molding of a resin material, for the manufacture of the flow path forming substrate 26, known materials and manufacturing methods can be arbitrarily adopted.

[0056] On the flow path forming substrate 26, an ink flow path is formed. Specifically, on the flow path forming substrate 26, a supply flow path BB1 and an introduction port HL1 are provided corresponding to the nozzle row Ln1. The supply flow path BB1 communicates with the supply flow path BA1 and is provided so as to extend in the Y-axis direction at a position in the Z2 direction when viewed from the supply flow path BA1. The introduction port HL1 communicates with the supply flow path BB1. In the supply flow path BB1, ink is supplied from the liquid container 93 via the introduction port HL1. The ink supplied from the liquid container 93 via the introduction port HL1 flows into the supply flow path BA1. A part of the ink flowing into the supply flow path BA1 is filled into the pressure chamber CV1 via the connection flow path BK1. When the piezoelectric element PZ1 is driven by the drive signal Com, a part of the ink filled into the pressure chamber CV1 is ejected from the nozzle N1 via the communication flow path BR1.

[0057] In addition, on the flow path forming substrate 26, a supply flow path BB2, which is an element symmetric to the supply flow path BB1, and an introduction port HL2, which is an element symmetric to the introduction port HL1, are provided corresponding to the nozzle row Ln2. Hereinafter, the supply flow path BB1 and the supply flow path BB2 may be collectively referred to as the supply flow path BB, and the introduction port HL1 and the introduction port HL2 may be collectively referred to as the introduction port HL.

[0058] Furthermore, a through hole 260 is provided in the flow path forming substrate 26. The through hole 260 is a hole that is located between the supply flow path BB1 and the supply flow path BB2 when the flow path forming substrate 26 is viewed in the Z1 direction and penetrates from the Z1-direction surface to the Z2-direction surface of the flow path forming substrate 26. A wiring substrate 4 is inserted through the through hole 260.

[0059] As Figure 2 and Figure 3As shown, a wiring board 4 is mounted on the surface of the actuator substrate AT in the Z2 direction, which includes a vibrating plate 24 and a piezoelectric structure 27. The wiring board 4 is a component for electrically connecting the liquid ejection head 1 and the control device 8. As the wiring board 4, for example, a flexible wiring board such as an FPC or an FFC is preferably used. Here, FPC is an abbreviation for Flexible Printed Circuit, and FFC is an abbreviation for Flexible Flat Cable. An integrated circuit 40 is mounted on the wiring board 4. The integrated circuit 40 is a circuit that switches whether to supply a drive signal Com to the piezoelectric element PZ under the control implemented by the control signal SI.

[0060] As Figure 2 and Figure 3 shown, when viewed from the communication board 22, at a position in the Z1 direction, a plastic sheet CS1 is provided so as to enclose the supply flow path BA1 and the connection flow path BK1 corresponding to the nozzle row Ln1. The plastic sheet CS1 is a plate-like member that is long and narrow in the Y-axis direction and extends substantially parallel to the XY plane. The plastic sheet CS1 is formed of an elastic material and absorbs pressure fluctuations of the ink in the supply flow path BA1 and the connection flow path BK1.

[0061] In addition, on the liquid ejection head 1, a plastic sheet CS2 is provided corresponding to the nozzle row Ln2 as an element symmetric to the plastic sheet CS1. Hereinafter, the plastic sheet CS1 and the plastic sheet CS2 may be collectively referred to as the plastic sheet CS.

[0062] A.3. Structure of the liquid ejection head

[0063] Hereinafter, while referring to Figures 4 to 7 the structure of the liquid ejection head 1 will be described.

[0064] Figure 4 FIG. is a cross-sectional view of the liquid ejection head 1 when the vicinity of the piezoelectric element PZ1 in the liquid ejection head 1 is observed in a cross-section along the Y2 direction. Figure 5 FIG. is a cross-sectional view of the liquid ejection head 1 when the vicinity of the piezoelectric element PZ2 in the liquid ejection head 1 is observed in a cross-section along the Y2 direction. In addition, Figure 4 , Figure 5 for simplicity, the scale in the X-axis direction is described in a different manner, and the actual scale can be, for example, a scale corresponding to Figure 3 For example, although in Figure 4is illustrated in such a manner that the width of the pressure chamber CV1 in the X-axis direction becomes approximately the same as the total value of the widths of the communication flow paths BC1 and BD1 in the X-axis direction, but actually, as Figure 3 shown, this side of the pressure chamber CV1 is larger.

[0065] As Figure 4 and Figure 5 shown, as described above, the liquid ejection head 1 includes a communication plate 22, a pressure chamber substrate 23, a diaphragm 24, a piezoelectric structure 27, and a sealing substrate 25. As described above, the structure including the diaphragm 24 and the piezoelectric structure 27 is referred to as an actuator substrate AT, and the structure including the actuator substrate AT, the pressure chamber substrate 23, and the sealing substrate 25 is referred to as an actuator chip AC.

[0066] As Figure 4 and Figure 5 shown, the diaphragm 24 includes an elastic film layer 241 and an insulating layer 242 laminated on the elastic film layer 241. The elastic film layer 241 is, for example, an elastic film formed of a silicon oxide such as silicon dioxide (SiO2). The insulating layer 242 is, for example, an insulating layer formed of a zirconium oxide such as zirconia (ZrO2). The piezoelectric structure 27 is formed on the insulating layer 242.

[0067] As Figure 4 shown, the piezoelectric structure 27 includes a plurality of piezoelectric elements PZ1 corresponding to the nozzle row Ln1 and corresponding to the plurality of nozzles N1, a plurality of individual wirings LC1 corresponding to the plurality of nozzles N1, a plurality of individual electrodes QC1 corresponding to the plurality of nozzles N1, one piezoelectric body Qm shared by the plurality of nozzles N1, one common electrode QB1 shared by the plurality of nozzles N1, one auxiliary electrode LA1 shared by the plurality of nozzles N1, one auxiliary electrode LB1 shared by the plurality of nozzles N1, one auxiliary electrode HC1 shared by the plurality of nozzles N1, one auxiliary electrode Hx11 shared by the plurality of nozzles N1, one auxiliary electrode Hx41 shared by the plurality of nozzles N1, and one auxiliary layer Hy1 shared by the plurality of nozzles N1.

[0068] As described above, the liquid ejection head 1 includes a plurality of piezoelectric elements PZ1 corresponding to a plurality of nozzles N1. The piezoelectric element PZ1 is a laminate in which a piezoelectric body Qm is interposed between a single electrode QC1 and a common electrode QB1. Specifically, the piezoelectric element PZ1 is a portion where the single electrode QC1, the common electrode QB1, and the piezoelectric body Qm overlap when the liquid ejection head 1 is viewed from above in the Z1 direction. In the first embodiment, as an example, a method is envisioned in which, in the piezoelectric element PZ1, the piezoelectric body Qm is provided at a position in the Z2 direction when viewed from the single electrode QC1, and the common electrode QB1 is provided at a position in the Z2 direction when viewed from the piezoelectric body Qm. However, it may also be configured such that, in the piezoelectric element PZ1, the piezoelectric body Qm is provided at a position in the Z1 direction when viewed from the single electrode QC1, and the common electrode QB1 is provided at a position in the Z1 direction when viewed from the piezoelectric body Qm.

[0069] The single electrode QC1 is formed of a conductive material such as platinum (Pt) or iridium (Ir). The single electrode QC1 is laminated on the diaphragm 24.

[0070] The piezoelectric body Qm is formed of a piezoelectric material such as lead zirconate titanate (Pb(Zr,Ti)O3). Hereinafter, the portion of the piezoelectric body Qm that constitutes the plurality of piezoelectric elements PZ1 is referred to as a piezoelectric body drive region RK1, and the portion that is provided at a position in the X1 direction and separated from the piezoelectric body drive region RK1 when viewed from the piezoelectric body drive region RK1 is referred to as a piezoelectric body outer edge region RG1.

[0071] The piezoelectric body drive region RK1 is laminated on the single electrode QC1. Further, when the liquid ejection head 1 is viewed from above in the Z1 direction, the piezoelectric body drive region RK1 is provided at a position where at least a part of the piezoelectric body drive region RK1 overlaps with at least a part of the pressure chamber CV1 and at least a part of the piezoelectric body drive region RK1 overlaps with at least a part of the wall WA1.

[0072] The piezoelectric body outer edge region RG1 is laminated on the auxiliary electrode HC1. When the liquid ejection head 1 is viewed from above in the Z1 direction, the piezoelectric body outer edge region RG1 is provided at a position where at least a part of the piezoelectric body outer edge region RG1 overlaps with at least a part of the wall WB1.

[0073] In addition, in the first embodiment, as an example, a case is envisioned in which the piezoelectric body Qm is provided such that the width of the piezoelectric body drive region RK1 in the X-axis direction is longer than the width of the piezoelectric body outer edge region RG1 in the X-axis direction.

[0074] The common electrode QB1 is formed of a conductive material such as platinum (Pt) or iridium (Ir). The common electrode QB1 is laminated on the piezoelectric drive region RK1 in the piezoelectric body Qm.

[0075] The auxiliary electrode HC1 is formed of the same conductive material as the individual electrode QC1 and is laminated on the insulating layer 242. The auxiliary electrode HC1 is electrically connected to the common electrode QB1 and is configured to be insulated from the individual electrode QC1.

[0076] The individual wiring LC1 is formed of a conductive material such as gold (Au). The individual wiring LC1 is laminated on the insulating layer 242, on the individual electrode QC1, and on the piezoelectric drive region RK1. The individual wiring LC1 is electrically connected to the individual electrode QC1 and supplies the drive signal Com supplied from the control device 8 to the individual electrode QC1. In addition, although in the first embodiment it is assumed that the individual wiring LC1 is directly laminated on the individual electrode QC1 to electrically connect the individual wiring LC1 and the individual electrode QC1, the present invention is not limited to such a method. The individual wiring LC1 may also be electrically connected to the individual electrode QC1 via a conductor provided in a contact hole provided in the piezoelectric drive region RK1 of the piezoelectric body Qm.

[0077] The auxiliary electrode LA1 is formed of a conductive material such as gold (Au). The auxiliary electrode LA1 is laminated on the common electrode QB1. The auxiliary electrode LA1 is electrically connected to the common electrode QB1.

[0078] The auxiliary electrode Hx11 is formed of the same conductive material as the common electrode QB1 and is laminated on the auxiliary electrode HC1. The auxiliary electrode Hx11 is electrically connected to the common electrode QB1 and is configured to be insulated from the individual electrode QC1.

[0079] The auxiliary electrode Hx41 is formed of the same conductive material as the common electrode QB1 and is laminated on the outer edge region RG1 of the piezoelectric body. The auxiliary electrode Hx41 is electrically connected to the common electrode QB1 and is configured to be insulated from the individual electrode QC1.

[0080] The auxiliary electrode LB1 is formed of a conductive material such as gold (Au). The auxiliary electrode LB1 is laminated on the common electrode QB1, on the auxiliary electrode HC1, on the auxiliary electrode Hx11, and on the auxiliary electrode Hx41, and electrically connects the common electrode QB1, the auxiliary electrode HC1, the auxiliary electrode Hx11, and the auxiliary electrode Hx41.

[0081] The auxiliary layer Hy1 is formed using a conductive material such as nickel-chromium alloy (NiCr). However, the auxiliary layer Hy1 can also be formed using a non-conductive material. The auxiliary layer Hy1 is laminated on the outer edge region RG1 of the piezoelectric body. The auxiliary layer Hy1 is configured to be in a state of being insulated from the individual electrode QC1 and the common electrode QB1.

[0082] As Figure 4 shown, the piezoelectric structure 27 includes an adhesive layer 50. The adhesive layer 50 is composed of an adhesive. The adhesive layer 50 bonds the individual wiring LC1, the piezoelectric body drive region RK1, and the wall WA1 of the auxiliary electrode LA1 and the sealing substrate 25. In addition, the adhesive layer 50 bonds the auxiliary electrode LB1, the outer edge region RG1 of the piezoelectric body, and the wall WB1 of the auxiliary layer Hy1 and the sealing substrate 25.

[0083] As Figure 5 shown, the piezoelectric structure 27 includes, corresponding to the nozzle row Ln2, a plurality of piezoelectric elements PZ2 as elements symmetric to the plurality of piezoelectric elements PZ1, a plurality of individual wirings LC2 as elements symmetric to the plurality of individual wirings LC1, a plurality of individual electrodes QC2 as elements symmetric to the plurality of individual electrodes QC1, one piezoelectric body Qm, one common electrode QB2 as an element symmetric to the one common electrode QB1, one auxiliary electrode LA2 as an element symmetric to the one auxiliary electrode LA1, one auxiliary electrode LB2 as an element symmetric to the one auxiliary electrode LB1, one auxiliary electrode HC2 as an element symmetric to the one auxiliary electrode HC1, one auxiliary electrode Hx12 as an element symmetric to the one auxiliary electrode Hx11, one auxiliary electrode Hx42 as an element symmetric to the one auxiliary electrode Hx41, and one auxiliary layer Hy2 as an element symmetric to the one auxiliary layer Hy1. In addition, the piezoelectric body Qm includes, corresponding to the nozzle row Ln2, a piezoelectric body drive region RK2 as an element symmetric to the piezoelectric body drive region RK1, and a piezoelectric body outer edge region RG2 as an element symmetric to the piezoelectric body outer edge region RG1.

[0084] Hereinafter, the individual wirings LC1 and LC2 are sometimes collectively referred to as the individual wiring LC, the individual electrodes QC1 and QC2 are collectively referred to as the individual electrode QC, the common electrodes QB1 and QB2 are collectively referred to as the common electrode QB, the auxiliary electrodes LA1 and LA2 are collectively referred to as the auxiliary electrode LA, the auxiliary electrodes LB1 and LB2 are collectively referred to as the auxiliary electrode LB, the auxiliary electrodes HC1 and HC2 are collectively referred to as the auxiliary electrode HC, the auxiliary electrodes Hx11 and Hx12 are collectively referred to as the auxiliary electrode Hx1, the auxiliary electrodes Hx41 and Hx42 are collectively referred to as the auxiliary electrode Hx4, the auxiliary layers Hy1 and Hy2 are collectively referred to as the auxiliary layer Hy, the piezoelectric body drive regions RK1 and RK2 are collectively referred to as the piezoelectric body drive region RK, and the piezoelectric body outer edge regions RG1 and RG2 are collectively referred to as the piezoelectric body outer edge region RG.

[0085] As Figure 4 shown, as described above, on the sealing substrate 25, a recess OB1 is provided corresponding to the nozzle row Ln1, and the recess OB1 defines a sealing space SP1 for accommodating a plurality of piezoelectric elements PZ1. Further, on the sealing substrate 25, a groove portion ON1 is provided in the wall WB1 corresponding to the nozzle row Ln1, and the groove portion ON1 is for accommodating the excess adhesive among the adhesives contained in the adhesive layer 50.

[0086] As Figure 5 shown, as described above, on the sealing substrate 25, a recess OB2, which is an element symmetric to the recess OB1, and a groove portion ON2, which is an element symmetric to the groove portion ON1, are provided corresponding to the nozzle row Ln2. Hereinafter, the groove portions ON1 and ON2 are sometimes collectively referred to as the groove portion ON.

[0087] Figure 6 FIG. 14 is a plan view of the actuator substrate AT when the actuator substrate AT provided on the liquid ejector head 1 is viewed from above in the Z1 direction. In addition, in Figure 6 , in addition to the actuator substrate AT including the diaphragm 24 and the piezoelectric body Qm, the sealing substrate 25 provided at the position (upper part) in the Z2 direction when viewed from the actuator substrate AT and a plurality of pressure chambers CV provided at the position (lower part) in the Z1 direction when viewed from the actuator substrate AT are depicted by dashed lines.

[0088] As described above, the actuator substrate AT has a diaphragm 24 and a piezoelectric body Qm laminated on the diaphragm 24.

[0089] As Figure 6As shown, as described above, the piezoelectric body Qm has a piezoelectric body drive region RK1 extending in the Y-axis direction corresponding to the nozzle row Ln1. When the liquid ejection head 1 is viewed from above, the piezoelectric body drive region RK1 is disposed so as to overlap with a plurality of pressure chambers CV1 and at least a part of the wall WA1.

[0090] In addition, a plurality of openings KK1 are provided in the piezoelectric body drive region RK1. The openings KK1 are through holes that penetrate the piezoelectric body drive region RK1 in the Z-axis direction. When the liquid ejection head 1 is viewed from above, each opening KK1 is disposed between two adjacent pressure chambers CV1 among the plurality of pressure chambers CV1 in the piezoelectric body drive region RK1. Since the piezoelectric body drive region RK1 has the openings KK1, when the piezoelectric element PZ1 corresponding to one of the two adjacent pressure chambers CV1 is driven by the drive signal Com, it is possible to suppress the transmission of the vibration generated by this drive to the piezoelectric element PZ1 corresponding to the other of the two adjacent pressure chambers CV1.

[0091] Furthermore, the boundary between the piezoelectric body drive region RK1, which is known as the active part of the piezoelectric body Qm here, and the passive part of the piezoelectric body Qm adjacent to it in the X2 direction is likely to cause damage to the piezoelectric body with use. Since the moving part and the non-moving part of the piezoelectric body Qm are adjacent during driving, the strain difference of the piezoelectric body Qm becomes large, which is considered to cause damage. To suppress this, in the present embodiment, when the liquid ejection head 1 is viewed from above, the boundary is set at a position overlapping with the wall WA1, and the wall WA1 is used to press the boundary. Thus, for example, even in the piezoelectric body drive region RK1, the part overlapping with the wall WA1 becomes less likely to move, so that the above damage can be reduced. To achieve this structure, as described above, a part of the piezoelectric body drive region RK1 is arranged so as to overlap with the wall WA when viewed from above.

[0092] Further, if the piezoelectric body Qm is also provided separately from the piezoelectric body driving region RK1 at a position overlapping with the wall WA1 when viewed from above, in the same manner as the position overlapping with the wall WB1 when viewed from above described later, it is possible to obtain the effect of reducing the inclusion of foreign matter or suppressing the deterioration of the sealing performance and ejection characteristics due to the transmission of vibration. However, compared with the wall WB1 side, the wall WA1 side is more greatly affected by the damage at the boundary between the active part and the passive part generated by the above use. This is considered to be caused by the following situations, etc. Since it is in a position closer to the nozzle N1, it may be impossible to perform the ejection itself when damage occurs. Since the drive signal Com is applied to the individual electrode QC1 from the wall WA1 side, the voltage on this side of the wall WA1 is more difficult to drop compared with the wall WB1, and thus it is more likely to withstand a larger voltage. Therefore, in the present embodiment, for the wall WA1 side, more importance is attached to reducing the damage generated by use, and a part of the piezoelectric body driving region RK1 overlaps with the wall WA1 when viewed from above.

[0093] In addition, as described above, the piezoelectric body Qm includes a piezoelectric body driving region RK2 as an element symmetric to the piezoelectric body driving region RK1 corresponding to the nozzle row Ln2. In the piezoelectric body driving region RK2, a plurality of openings KK2 are provided as elements symmetric to the plurality of openings KK1.

[0094] As Figure 6 shown, the piezoelectric body Qm includes a piezoelectric outer edge region RG1 corresponding to the nozzle row Ln1. When the liquid ejection head 1 is viewed from above, the piezoelectric outer edge region RG1 overlaps at least a part of the wall WB1 and is provided separately from the piezoelectric body driving region RK1.

[0095] The outer edge region RG1 of the piezoelectric body has an extension portion RGy extending in the Y-axis direction at a position in the X1 direction when observed from the piezoelectric body drive region RK1, and two extension portions RGx extending in the X-axis direction at positions in the Y1 direction and the Y2 direction when observed from the piezoelectric body drive region RK1. The extension portion RGy has a central portion RGm overlapping with a plurality of pressure chambers CV1 when the liquid ejection head 1 is observed in the X-axis direction, and end portions RGs not overlapping with the plurality of pressure chambers CV1 when the liquid ejection head 1 is observed in the X-axis direction. In the first embodiment, as an example, it is assumed that the outer edge region RG1 of the piezoelectric body is provided such that the width of the central portion RGm in the X-axis direction is longer than the width of the end portions RGs in the X-axis direction. Further, in the first embodiment, as an example, it is assumed that the outer edge region RG1 of the piezoelectric body is provided such that the width of the central portion RGm in the X-axis direction is longer than the width of the extension portion RGx in the Y-axis direction.

[0096] In addition, as described above, the piezoelectric body Qm includes, corresponding to the nozzle row Ln2, an outer edge region RG2 of the piezoelectric body as an element symmetric to the outer edge region RG1 of the piezoelectric body. The outer edge region RG2 of the piezoelectric body includes an extension portion RGy and an extension portion RGx.

[0097] As Figure 6 shown, the piezoelectric body Qm includes, corresponding to the nozzle row Ln1, a central region RP1 of the piezoelectric body extending in the Y-axis direction. In the case of a plan view of the liquid ejection head 1, the central region RP1 of the piezoelectric body is provided so as to overlap with the wiring substrate 4. At the upper part of the central region RP1 of the piezoelectric body, a conductive wiring (not shown) for electrically connecting the wiring provided on the wiring substrate 4 and the individual wiring LC is provided.

[0098] In addition, as described above, the piezoelectric body Qm includes, corresponding to the nozzle row Ln2, a central region RP2 of the piezoelectric body as an element symmetric to the central region RP1 of the piezoelectric body. Hereinafter, the central region RP1 of the piezoelectric body and the central region RP2 of the piezoelectric body may be collectively referred to as the central region RP of the piezoelectric body.

[0099] Figure 7 FIG. 15 is a plan view of the pressure chamber substrate 23 in the vicinity of the pressure chamber CV1 among the pressure chamber substrates 23 provided on the liquid ejection head 1 when viewed from above in the Z1 direction.

[0100] As Figure 7As shown, on the pressure chamber substrate 23, a pressure chamber CV1, a communication flow path BC1, and a communication flow path BD1 are formed corresponding to the nozzle row Ln1. The pressure chamber CV1 extends in the X-axis direction and communicates with the communication flow path BR1. The communication flow path BC1 extends in the X-axis direction and communicates with the connection flow path BK1. The communication flow path BD1 extends in the X-axis direction and connects the pressure chamber CV1 and the communication flow path BC1. In the first embodiment, the cross-sectional area of the communication flow path BD1 is smaller than that of the pressure chamber CV1 and smaller than that of the communication flow path BC1. For example, when the pressure chamber substrate 23 is viewed from above in the Z-axis direction, the width dBD of the communication flow path BD1 in the Y-axis direction is shorter than the width dBC of the communication flow path BC1 in the Y-axis direction and shorter than the width dCV of the pressure chamber CV1 in the Y-axis direction. In addition, the part of the pressure chamber substrate 23 that defines the wall surface of the communication flow path BD1 is referred to as a throttling portion SB1.

[0101] In addition, as described above, on the pressure chamber substrate 23, a pressure chamber CV2, which is an element symmetric to the pressure chamber CV1, a communication flow path BC2, which is an element symmetric to the communication flow path BC1, and a communication flow path BD2, which is an element symmetric to the communication flow path BD1, are formed corresponding to the nozzle row Ln2.

[0102] A.4. Reference Example

[0103] Hereinafter, in order to clarify the characteristics of the liquid ejector head 1 according to the first embodiment, the liquid ejector head 1Z according to Reference Example 1 and the liquid ejector head 1W according to Reference Example 2 will be described.

[0104] Figure 8 FIG. is a cross-sectional view of the liquid ejector head 1Z when the liquid ejector head 1Z according to Reference Example 1 is viewed in a sectional view along the Y2 direction. Figure 9 FIG. is a top view of the actuator substrate AT-Z when the actuator substrate AT-Z provided on the liquid ejector head 1Z is viewed from above in the Z1 direction.

[0105] As Figure 8 and Figure 9 shown, the liquid ejector head 1Z is different from the liquid ejector head 1 according to the first embodiment in that a piezoelectric structure 27Z having a piezoelectric body QmZ is provided instead of the piezoelectric structure 27 having a piezoelectric body Qm. The piezoelectric body QmZ is different from the piezoelectric body Qm according to the first embodiment in that a piezoelectric body extension region RZ1 is provided corresponding to the nozzle row Ln1 instead of the piezoelectric body drive region RK1 and the piezoelectric body outer edge region RG1.

[0106] Here, as Figure 8and Figure 9 As shown in Figure 9 , when the liquid ejection head 1Z is viewed from above in the Z1 direction, the piezoelectric body extension region RZ1 is set within a range where at least a part of the piezoelectric body extension region RZ1 overlaps with the pressure chamber CV1, at least a part of the piezoelectric body extension region RZ1 overlaps with at least a part of the wall WA1, and at least a part of the piezoelectric body extension region RZ1 overlaps with at least a part of the wall WB1. That is, as in the prior art, the piezoelectric body extension region RZ1 of the piezoelectric body QmZ is a region obtained by expanding the extension ranges of the piezoelectric body drive region RK1 and the piezoelectric body outer edge region RG1 of the piezoelectric body Qm and expanding the extension range of the piezoelectric body Qm in such a way that the piezoelectric body drive region RK1 and the piezoelectric body outer edge region RG1 are connected as one.

[0107] In addition, the liquid ejection head 1Z is different from the liquid ejection head 1 according to the first embodiment in that the piezoelectric element PZ-Z1 is provided instead of the piezoelectric element PZ1. The piezoelectric element PZ-Z1 is different from the piezoelectric element PZ1 according to the first embodiment in that the piezoelectric body QmZ is provided instead of the piezoelectric body Qm. In addition, the piezoelectric structure 27Z is different from the piezoelectric structure 27 according to the first embodiment in that the auxiliary electrode LBZ1 laminated on the piezoelectric body QmZ is provided instead of the auxiliary electrode LB1. In addition, the piezoelectric structure 27Z is different from the piezoelectric structure 27 according to the first embodiment in that the auxiliary electrode Hx11 and the auxiliary electrode Hx41 are not provided.

[0108] Hereinafter, as Figure 8 shown in Figure 8 , the region of the piezoelectric body extension region RZ1 of the piezoelectric body QmZ that constitutes the piezoelectric element PZ-Z1 is referred to as the piezoelectric body drive region RZK1. In addition, hereinafter, the portion of the piezoelectric body extension region RZ1 that is located at the lower part of the wall WB1 and supports the wall WB1 is referred to as the piezoelectric body outer edge region RZG1. In addition, hereinafter, the portion between the piezoelectric body drive region RZK1 and the piezoelectric body outer edge region RZG1 in the piezoelectric body extension region RZ1 is referred to as the piezoelectric body connection region RZM1.

[0109] In addition, it is assumed that the liquid ejection head 1Z has a substantially bilaterally symmetric structure with a plane having the X-axis direction as the normal direction as a symmetry plane. Specifically, the liquid ejection head 1Z includes a piezoelectric body extension region RZ2 as an element symmetric to the piezoelectric body extension region RZ1, a piezoelectric element PZ-Z2 as an element symmetric to the piezoelectric element PZ-Z1, and an auxiliary electrode LBZ2 as an element symmetric to the auxiliary electrode LBZ1 corresponding to the nozzle row Ln2. Hereinafter, the piezoelectric body extension region RZ1 and the piezoelectric body extension region RZ2 may be collectively referred to as the piezoelectric body extension region RZ, the piezoelectric element PZ-Z1 and the piezoelectric element PZ-Z2 may be collectively referred to as the piezoelectric element PZ-Z, and the auxiliary electrode LBZ1 and the auxiliary electrode LBZ2 may be collectively referred to as the auxiliary electrode LBZ.

[0110] Thus, in the liquid ejection head 1Z according to the reference example 1, the piezoelectric body extension region RZ1 included in the piezoelectric body QmZ includes a piezoelectric body drive region RZK1 located above the pressure chamber CV1 and constituting the piezoelectric element PZ-Z1, a piezoelectric body outer edge region RZG1 located below the wall WB1, and a piezoelectric body connection region RZM1 connecting the piezoelectric body drive region RZK1 and the piezoelectric body outer edge region RZG1, and extends widely in the X-axis direction from the lower part of the wall WA1 to the lower part of the wall WB1. Moreover, in the reference example 1, since the piezoelectric body extension region RZ1 includes the piezoelectric body connection region RZM1 and has a large area, for example, compared with a case where the piezoelectric body connection region RZM1 is not included, when the actuator substrate AT-Z and the sealing substrate 25 having the piezoelectric structure 27Z including the piezoelectric body QmZ are bonded by the adhesive layer 50, the possibility of foreign matter being mixed between the actuator substrate AT-Z and the sealing substrate 25 becomes higher. Further, when foreign matter is mixed between the actuator substrate AT-Z and the sealing substrate 25, when the piezoelectric element PZ-Z1 having the piezoelectric body QmZ included in the actuator substrate AT-Z is driven by the drive signal Com, due to the influence of the foreign matter, there is a possibility that the piezoelectric element PZ-Z1 is driven in a manner different from the manner specified by the drive signal Com. That is, when foreign matter is mixed between the actuator substrate AT-Z and the sealing substrate 25, due to the influence of the foreign matter, there is a possibility that the ejection performance of the ink ejected from the liquid ejection head 1Z deteriorates.

[0111] In contrast, in the first embodiment, the piezoelectric drive region RK1 and the piezoelectric outer edge region RG1 included in the piezoelectric body Qm are provided separately from each other. That is, according to the first embodiment, the piezoelectric drive region RK1 located above the pressure chamber CV1 and constituting the piezoelectric element PZ1 and the piezoelectric outer edge region RG1 located below the wall WB1 are provided separately from each other. Therefore, according to the first embodiment, compared with Reference Example 1, the area of the piezoelectric body Qm when observed in the Z-axis direction can be reduced. Thus, according to the first embodiment, compared with Reference Example 1, the possibility of foreign matter mixing between the actuator substrate AT and the sealing substrate 25 can be reduced, and the possibility of the ejection performance of the ink ejected from the liquid ejection head 1 deteriorating due to the influence of the foreign matter mixed between the actuator substrate AT and the sealing substrate 25 can be reduced.

[0112] In addition, in the liquid ejection head 1Z according to Reference Example 1, when the piezoelectric element PZ-Z1 is driven by the drive signal Com and the piezoelectric drive region RZK1 in the piezoelectric extension region RZ1 included in the piezoelectric body QmZ vibrates, the vibration generated in the piezoelectric drive region RZK1 is transmitted to the piezoelectric outer edge region RZG1 via the piezoelectric connection region RZM1. Moreover, in Reference Example 1, due to the vibration transmitted to the piezoelectric outer edge region RZG1, the sealing substrate 25 located above the piezoelectric outer edge region RZG1 and the pressure chamber substrate 23 located below the piezoelectric outer edge region RZG1 are displaced. Moreover, when the sealing substrate 25 is displaced, the sealing performance of the piezoelectric element PZ-Z1 achieved by the sealing space SP1 deteriorates. In addition, since the volume and shape of the pressure chamber CV1 change when the pressure chamber substrate 23 is displaced, the ejection performance of the ink ejected from the liquid ejection head 1Z deteriorates. Thus, according to Reference Example 1, the possibility of a decrease in the sealing performance of the piezoelectric element PZ-Z1 and a decrease in the ejection performance of the liquid ejection head 1Z due to the vibration transmitted from the piezoelectric drive region RZK1 to the piezoelectric outer edge region RZG1 via the piezoelectric connection region RZM1 becomes high.

[0113] In contrast, in the first embodiment, as described above, since the piezoelectric drive region RK1 and the piezoelectric outer edge region RG1 are separated from each other, compared with Reference Example 1, the degree of transmission of the vibration generated in the piezoelectric drive region RK1 to the piezoelectric outer edge region RG1 when the piezoelectric element PZ1 is driven by the drive signal Com can be reduced. Therefore, according to the first embodiment, compared with Reference Example 1, the deterioration of the sealing performance of the piezoelectric element PZ1 can be reduced, and the deterioration of the ejection performance obtained by the liquid ejection head 1 can be reduced.

[0114] Figure 10 FIG. 2 is a cross-sectional view of the liquid ejection head 1W when viewed from above in the Y2 direction with respect to the liquid ejection head 1W according to Reference Example 2. Figure 11 FIG. 3 is a top view of the actuator substrate AT-W provided on the liquid ejection head 1W when viewed from above in the Z1 direction.

[0115] As Figure 10 and Figure 11 shown, the liquid ejection head 1W is different from the liquid ejection head 1 according to the first embodiment in that a piezoelectric structure 27W having a piezoelectric body QmW is provided instead of the piezoelectric structure 27 having a piezoelectric body Qm. The piezoelectric body QmW is different from the piezoelectric body Qm according to the first embodiment in that it does not have a piezoelectric outer edge region RG1 corresponding to the nozzle row Ln1. That is, the piezoelectric body QmW has a piezoelectric drive region RK1 and a piezoelectric central region RP1 corresponding to the nozzle row Ln1.

[0116] In addition, the liquid ejection head 1W is different from the liquid ejection head 1 according to the first embodiment in that a piezoelectric element PZ-W1 is provided instead of the piezoelectric element PZ1. The piezoelectric element PZ-W1 is different from the piezoelectric element PZ1 according to the first embodiment in that it has a piezoelectric body QmW instead of the piezoelectric body Qm. In addition, the piezoelectric structure 27W is different from the piezoelectric structure 27 according to the first embodiment in that an auxiliary electrode LBW1 laminated on the piezoelectric body QmZ is provided instead of the auxiliary electrode LB1. In addition, the piezoelectric structure 27W is different from the piezoelectric structure 27 according to the first embodiment in that it does not have the auxiliary electrode Hx11, the auxiliary electrode Hx41, and the auxiliary electrode HC1.

[0117] In addition, it is assumed that the liquid ejection head 1W has a substantially plane-symmetric structure with a plane having the X-axis direction as the normal direction as a symmetric plane. Specifically, the liquid ejection head 1W has a piezoelectric element PZ-W2 as an element symmetric to the piezoelectric element PZ-W1 and an auxiliary electrode LBW2 as an element symmetric to the auxiliary electrode LBW1 corresponding to the nozzle row Ln2. Hereinafter, the piezoelectric element PZ-W1 and the piezoelectric element PZ-W2 may be collectively referred to as the piezoelectric element PZ-W, and the auxiliary electrode LBW1 and the auxiliary electrode LBW2 may be collectively referred to as the auxiliary electrode LBW.

[0118] As described above, in the liquid ejection head 1W according to Reference Example 2, the piezoelectric body QmW includes a piezoelectric body driving region RK1 having an area smaller than that of the outer edge region RG1 of the piezoelectric body. Therefore, according to Reference Example 2, compared with the method of disposing the piezoelectric body QmZ having a larger outer edge region RZG1 of the piezoelectric body in the liquid ejection head 1Z as in Reference Example 1, when the actuator substrate AT-W and the sealing substrate 25 are bonded by the bonding layer 50, the possibility of foreign matter being mixed between the actuator substrate AT-W and the sealing substrate 25 can be reduced.

[0119] However, as Figure 10 shown, in the piezoelectric structure 27W according to Reference Example 2, at the lower part of the wall WA1, in addition to the bonding layer 50 and the individual electrode QC1, a piezoelectric body QmW, an individual wiring LC1, and an auxiliary electrode LA1 are provided. On the other hand, at the lower part of the wall WB1, only the bonding layer 50 and the auxiliary layer Hy1 are provided. That is, in Reference Example 2, the thickness of the bonding layer 50 at the lower part of the wall WA1 is different from the thickness of the bonding layer 50 at the lower part of the wall WB1. Therefore, compared with Reference Example 1, in Reference Example 2, the adhesiveness of the piezoelectric structure 27W to the sealing substrate 25 is reduced, and the strength of the actuator chip including the actuator substrate AT-W and the sealing substrate 25 is reduced.

[0120] In contrast, in the first embodiment, the piezoelectric body Qm includes an outer edge region RG1 of the piezoelectric body in addition to the piezoelectric body driving region RK1. Further, in the first embodiment, an individual wiring LC1 and an auxiliary electrode LA1 are provided on the piezoelectric body driving region RK1, and an auxiliary electrode LB1 is provided on the outer edge region RG1 of the piezoelectric body. Therefore, in the first embodiment, the thickness of the bonding layer 50 at the lower part of the wall WA1 can be made substantially the same as the thickness of the bonding layer 50 at the lower part of the wall WB1. Therefore, compared with Reference Example 2, in the first embodiment, the adhesiveness of the piezoelectric structure 27 to the sealing substrate 25 can be improved, and thereby, the strength of the actuator chip AC including the actuator substrate AT and the sealing substrate 25 can be improved.

[0121] As described above, according to the first embodiment, it is possible to simultaneously reduce the possibility of foreign matter being mixed between the actuator substrate AT and the sealing substrate 25, reduce the possibility of a decrease in the sealing performance of the piezoelectric element PZ1 achieved by the sealing substrate 25, and ensure the strength of the actuator chip AC.

[0122] A.5. Conclusion of the First Embodiment

[0123] As described above, the liquid ejection head 1 according to the first embodiment is characterized by including: a pressure chamber substrate 23 provided with a plurality of pressure chambers CV including a pressure chamber CV1 and a pressure chamber CV2, wherein the pressure chamber CV1 extends in the X1 direction, and the pressure chamber CV2 is provided at a position different from the pressure chamber CV1 in the X1 direction and extends in the X1 direction; a plurality of piezoelectric elements PZ, the plurality of piezoelectric elements PZ being arranged at positions in the Z2 direction when viewed from the pressure chamber substrate 23, and including a piezoelectric body Qm, a common electrode QB, and an individual electrode QC; a sealing substrate 25 provided with a recess OB1 and a recess OB2, and arranged at a position in the Z2 direction when viewed from the plurality of piezoelectric elements PZ, wherein the recess OB1 houses the piezoelectric element PZ1 corresponding to the pressure chamber CV1 among the plurality of piezoelectric elements PZ, and the recess OB2 houses the piezoelectric element PZ2 corresponding to the pressure chamber CV2 among the plurality of piezoelectric elements PZ. When the liquid ejection head 1 is viewed from above with respect to the Z1 direction, the piezoelectric body Qm has: a piezoelectric body driving region RK1 overlapping with the pressure chamber CV1; a piezoelectric body outer edge region RG1 overlapping with a wall WB1 of two walls of the recess OB1 in the X1 direction; a piezoelectric body driving region RK2 overlapping with the pressure chamber CV2; a piezoelectric body outer edge region RG2 overlapping with a wall WB2 of two walls of the recess OB2 in the X1 direction. The piezoelectric body driving region RK1 is located between the piezoelectric body outer edge region RG1 and the piezoelectric body driving region RK2 in the X1 direction and is provided so as to be separated from the piezoelectric body outer edge region RG1. The piezoelectric body driving region RK2 is located between the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG2 in the X1 direction and is provided so as to be separated from the piezoelectric body outer edge region RG2.

[0124] Thus, according to the liquid ejection head 1 according to the first embodiment, since the piezoelectric body drive region RK1 and the piezoelectric body outer edge region RG1 are provided in a separated manner, the possibility of foreign matter entering between the piezoelectric body Qm and the sealing substrate 25 can be reduced compared to the case where the piezoelectric body drive region RK1 and the piezoelectric body outer edge region RG1 are provided continuously. Moreover, even when foreign matter enters between the piezoelectric body Qm and the sealing substrate 25, the possibility of the relative positional relationship between the piezoelectric body Qm and the sealing substrate 25 being changed due to the foreign matter can be reduced. Therefore, according to the first embodiment, compared to the case where the piezoelectric body drive region RK1 and the piezoelectric body outer edge region RG1 are provided continuously, the variation in ejection characteristics caused by foreign matter entering between the piezoelectric body Qm and the sealing substrate 25 can be suppressed. In addition, according to the first embodiment, compared to the case where the piezoelectric body drive region RK1 and the piezoelectric body outer edge region RG1 are provided continuously, the variation in the relative positional relationship between the piezoelectric body Qm and the sealing substrate 25 caused by foreign matter entering between the piezoelectric body Qm and the sealing substrate 25 can be suppressed, and further, the variation in ejection characteristics caused by the variation in the relative positional relationship between the piezoelectric body Qm and the sealing substrate 25 can be suppressed.

[0125] Moreover, according to the liquid ejection head 1 according to the first embodiment, since the piezoelectric body drive region RK1 and the piezoelectric body outer edge region RG1 are provided in a separated manner, the degree of vibration generated in the piezoelectric body drive region RK1 being transmitted to the piezoelectric body outer edge region RG1 when the piezoelectric element PZ1 is driven by the drive signal Com can be reduced compared to the case where the piezoelectric body drive region RK1 and the piezoelectric body outer edge region RG1 are provided continuously. Therefore, according to the first embodiment, compared to the case where the piezoelectric body drive region RK1 and the piezoelectric body outer edge region RG1 are provided continuously, the possibility of displacement of the pressure chamber substrate 23 caused by vibration of the piezoelectric body outer edge region RG1 can be reduced, and further, the possibility of the volume and shape of the pressure chamber CV1 being changed due to the displacement of the pressure chamber substrate 23 can be reduced. Thus, according to the first embodiment, compared to the case where the piezoelectric body drive region RK1 and the piezoelectric body outer edge region RG1 are provided continuously, the variation in the ejection performance of the liquid ejection head 1 caused by the variation in the volume and shape of the pressure chamber CV1 can be suppressed.

[0126] In addition, in the first embodiment, the X1 direction is an example of the "first direction", the Z2 direction is an example of the "upper part", the pressure chamber CV1 is an example of the "first pressure chamber", the pressure chamber CV2 is an example of the "second pressure chamber", the common electrode QB is an example of the "upper electrode", the individual electrode QC is an example of the "lower electrode", the piezoelectric element PZ1 is an example of the "first piezoelectric element", the piezoelectric element PZ2 is an example of the "second piezoelectric element", the recess OB1 is an example of the "first recess", the recess OB2 is an example of the "second recess", the sealing substrate 25 is an example of the "sealing plate", the piezoelectric body driving region RK1 is an example of the "first region", the outer edge region RG1 of the piezoelectric body is an example of the "second region", the piezoelectric body driving region RK2 is an example of the "third region", the outer edge region RG2 of the piezoelectric body is an example of the "fourth region", the wall WB1 is an example of "one of the two walls of the first recess", and the wall WB2 is an example of "one of the two walls of the second recess".

[0127] In addition, although in the first embodiment, the liquid ejection head 1 having structural elements corresponding to the nozzle row Ln1 and structural elements corresponding to the nozzle row Ln2 is illustrated and described, the present invention is not limited to such a manner. The liquid ejection head 1 may also be a liquid ejection head having structural elements corresponding to one nozzle row Ln.

[0128] That is, it may also be set that the liquid ejection head 1 according to the first embodiment is characterized by including: a pressure chamber substrate provided with a first pressure chamber extending in the first direction; a first piezoelectric element disposed above the pressure chamber substrate and including a piezoelectric body, an upper electrode, and a lower electrode; and a sealing plate disposed above the first piezoelectric element and provided with a first recess for housing the first piezoelectric element. When the liquid ejection head is viewed from above with respect to the vertical direction, the piezoelectric body has a first region and a second region, where the first region overlaps with the first pressure chamber, the second region overlaps with one of the two walls of the first recess in the first direction, and the first region is provided so as to be separated from the second region.

[0129] In addition, it may also be set that the liquid ejection head 1 according to the first embodiment is characterized in that when the liquid ejection head 1 is viewed from above, the piezoelectric body driving region RK1 overlaps with the wall WA1 of the two walls of the recess OB1 in the X1 direction.

[0130] In addition, in the first embodiment, the wall WA1 is an example of "the other of the two walls of the first recess".

[0131] In addition, it can also be set that the liquid ejection head 1 according to the first embodiment is characterized in that an auxiliary electrode LA1 containing Au is formed on the upper part of at least a part of the piezoelectric drive region RK1.

[0132] Therefore, the liquid ejection head 1 according to the first embodiment can lower the resistance of the common electrode QB1 provided on the piezoelectric drive region RK1, thereby reducing the possibility that the potential of the common electrode QB1 changes from the desired potential. As a result, the liquid ejection head 1 according to the first embodiment can suppress the decrease in the ejection performance of the liquid ejection head 1 caused by the change in the potential of the common electrode QB1 from the desired potential.

[0133] In addition, in the first embodiment, the auxiliary electrode LA1 is an example of a "conductive layer".

[0134] In addition, it can also be set that the liquid ejection head 1 according to the first embodiment is characterized in that an auxiliary layer Hy1 containing NiCr is formed on the upper part of at least a part of the piezoelectric outer edge region RG1.

[0135] Therefore, the liquid ejection head 1 according to the first embodiment can easily bond the piezoelectric body Qm and the sealing substrate 25 with an adhesive as compared with a mode in which no auxiliary layer Hy1 is provided on the piezoelectric outer edge region RG1.

[0136] In addition, it can also be set that the liquid ejection head 1 according to the first embodiment is characterized in that the width of the piezoelectric drive region RK1 in the X1 direction is longer than the width of the piezoelectric outer edge region RG1 in the X1 direction.

[0137] Therefore, the liquid ejection head 1 according to the first embodiment can increase the amplitude of the piezoelectric drive region RK1 when the piezoelectric element PZ1 is driven as compared with a mode in which the width of the piezoelectric drive region RK1 in the X1 direction is shorter than the width of the piezoelectric outer edge region RG1 in the X1 direction, thereby ensuring good ejection performance of the liquid ejection head 1.

[0138] In addition, it can also be set that the liquid ejection head 1 according to the first embodiment is characterized in that the piezoelectric outer edge region RG1 has: a central portion RGm that overlaps with a plurality of pressure chambers CV when observing the piezoelectric outer edge region RG1 in the X1 direction; and both end portions RGs that do not overlap with a plurality of pressure chambers CV when observing the piezoelectric outer edge region RG1 in the X1 direction, and the width of the central portion RGm in the X1 direction is longer than the width of the both end portions RGs in the X1 direction.

[0139] Therefore, compared with the case where the width of the central portion RGm in the X1 direction of the liquid ejection head 1 according to the first embodiment is shorter than the width of the both end portions RGs in the X1 direction, it is possible to ensure the strength of the central portion RGm in the outer edge region RG1 of the piezoelectric body, which is the portion where vibrations from the piezoelectric body driving region RK1 will propagate when the piezoelectric element PZ is driven. In addition, compared with the case where the width of the both end portions RGs in the X1 direction is longer than the width of the central portion RGm in the X1 direction, the liquid ejection head 1 according to the first embodiment can reduce the possibility of foreign matter entering between the piezoelectric body Qm and the sealing substrate 25 due to the reduction in the area of the piezoelectric body Qm. That is, according to the liquid ejection head 1 according to the first embodiment, it is possible to simultaneously ensure the strength of the portion in the outer edge region RG1 of the piezoelectric body where vibrations from the piezoelectric body driving region RK1 will propagate when the piezoelectric element PZ is driven, and reduce the possibility of foreign matter entering between the piezoelectric body Qm and the sealing substrate 25 due to the reduction in the area of the piezoelectric body Qm.

[0140] In addition, in the first embodiment, the central portion RGm is an example of the "first partial region", and the both end portions RGs are an example of the "second partial region".

[0141] Furthermore, it may be configured such that the liquid ejection head 1 according to the first embodiment is characterized in that the plurality of pressure chambers CV include a plurality of pressure chambers CV1 arranged along the Y1 direction intersecting the X1 direction, the outer edge region RG1 of the piezoelectric body has an extension portion RGx extending in the X1 direction and an extension portion RGy extending in the Y1 direction, the extension portion RGx has a first extension portion region that overlaps the plurality of pressure chambers CV1 when the extension portion RGx is observed along the Y1 direction, the extension portion RGy has a central portion RGm (an example of the "second extension portion region") that overlaps the plurality of pressure chambers CV1 when the extension portion RGy is observed along the X1 direction, and the width of the second extension portion region in the X1 direction is longer than the width of the first extension portion region in the Y1 direction.

[0142] Therefore, compared with the case where the width in the X1 direction of the second extension portion region of the liquid ejection head 1 according to the first embodiment is shorter than the width in the Y1 direction of the first extension portion region, it is possible to ensure the strength of the second extension portion region, which is a part of the outer edge region RG1 of the piezoelectric body and through which vibration propagates from the piezoelectric body driving region RK1 when the piezoelectric element PZ is driven. In addition, compared with the case where the width in the Y1 direction of the first extension portion region is longer than the width in the X1 direction of the second extension portion region, the liquid ejection head 1 according to the first embodiment can reduce the possibility of foreign matter entering between the piezoelectric body Qm and the sealing substrate 25 due to the reduction in the area of the piezoelectric body Qm. That is, according to the liquid ejection head 1 according to the first embodiment, it is possible to simultaneously ensure the strength of the part of the outer edge region RG1 of the piezoelectric body through which vibration propagates from the piezoelectric body driving region RK1 when the piezoelectric element PZ is driven, and reduce the possibility of foreign matter entering between the piezoelectric body Qm and the sealing substrate 25 due to the reduction in the area of the piezoelectric body Qm.

[0143] In addition, in the first embodiment, the Y1 direction is an example of the "second direction", the extension portion RGx is an example of the "first extension region", and the extension portion RGy is an example of the "second extension region".

[0144] B. Second Embodiment

[0145] Hereinafter, the liquid ejection device according to the second embodiment will be described while referring to Figure 12 and Figure 13 In addition, in each of the embodiments illustrated below, for elements having the same functions and operations as those in the first embodiment, the symbols used in the description of the first embodiment are used, and their detailed descriptions are appropriately omitted.

[0146] B.1. Outline of the Liquid Ejection Head According to the Second Embodiment

[0147] The liquid ejection device according to the second embodiment is different from the liquid ejection device 100 according to the first embodiment in that it includes a liquid ejection head 1B instead of the liquid ejection head 1.

[0148] Figure 12 FIG. is a cross-sectional view of the liquid ejection head 1B when the liquid ejection head 1B according to the second embodiment is observed in a cross-section along the Y2 direction. Figure 13 FIG. is a top view of the actuator substrate AT-B when the actuator substrate AT-B provided on the liquid ejection head 1B is observed in a top view along the Z1 direction.

[0149] Z As Figure 12 and Figure 13As shown, the liquid ejection head 1B is different from the liquid ejection head 1 according to the first embodiment in that a piezoelectric structure 27B having a piezoelectric body QmB is provided instead of the piezoelectric structure 27 having a piezoelectric body Qm. The piezoelectric body QmB is different from the piezoelectric body Qm according to the first embodiment in that, corresponding to the nozzle row Ln1, in addition to having a piezoelectric body drive region RK1, a piezoelectric outer edge region RG1, and a piezoelectric central region RP1, it also has a piezoelectric body support region RS1.

[0150] Here, as Figure 12 and Figure 13 shown, the piezoelectric body support region RS1 is located between the piezoelectric body drive region RK1 and the piezoelectric outer edge region RG1 in the X-axis direction, and is provided so as to be separated from the piezoelectric body drive region RK1 and the piezoelectric outer edge region RG1.

[0151] In addition, when the liquid ejection head 1B is viewed from above in the Z1 direction, the piezoelectric body support region RS1 is provided at a position where at least a part of the piezoelectric body support region RS1 overlaps with at least a part of the wall WB1.

[0152] Further, hereinafter, the region including the end portion of the wall WB1 in the X-axis direction that is located in the X1 direction will be referred to as the end region Wt1, and the region including the end portion in the X2 direction will be referred to as the end region Wt2. In the second embodiment, when the liquid ejection head 1B is viewed from above in the Z1 direction, the piezoelectric body support region RS1 is provided at a position where at least a part of the piezoelectric body support region RS1 overlaps with at least a part of the end region Wt2. In addition, when the liquid ejection head 1B is viewed from above in the Z1 direction, the piezoelectric outer edge region RG1 may also be provided at a position where at least a part of the piezoelectric outer edge region RG1 overlaps with at least a part of the end region Wt1. However, the present invention is not limited to such a manner. When the liquid ejection head 1B is viewed from above in the Z1 direction, the piezoelectric body support region RS1 may also be provided at a position where the piezoelectric body support region RS1 does not overlap with the end region Wt2. In addition, when the liquid ejection head 1B is viewed from above in the Z1 direction, the piezoelectric outer edge region RG1 may also be provided at a position where the piezoelectric outer edge region RG1 does not overlap with the end region Wt1.

[0153] In addition, in the second embodiment, as an example, the following situation is envisaged. That is, when the liquid ejection head 1B is viewed from above in the Z1 direction, the piezoelectric body support region RS1 is provided at a position where at least a part of the piezoelectric body support region RS1 overlaps with at least a part of the throttle portion SB1. However, the present invention is not limited to such a manner. When the liquid ejection head 1B is viewed from above in the Z1 direction, the piezoelectric body support region RS1 may also be provided at a position where the piezoelectric body support region RS1 does not overlap with the throttle portion SB1.

[0154] In addition, in the second embodiment, as an example, the following situation is envisaged. That is, the piezoelectric body QmB is arranged such that the width of the piezoelectric body drive region RK1 in the X-axis direction is longer than the width of the piezoelectric outer edge region RG1 in the X-axis direction, and the width of the piezoelectric outer edge region RG1 in the X-axis direction is longer than the width of the piezoelectric body support region RS1 in the X-axis direction. However, the width of the piezoelectric outer edge region RG1 in the X-axis direction may also be equal to or less than the width of the piezoelectric body support region RS1 in the X-axis direction.

[0155] In addition, in the second embodiment, as Figure 13 shown, the following situation is envisaged. That is, the piezoelectric body support region RS1 has an extension portion RSy1 and an extension portion RSy2. The extension portion RSy1 extends in the X-axis direction at a position in the Y1 direction when viewed from the plurality of pressure chambers CV1 provided in the liquid ejection head 1B, and the extension portion RSy2 extends in the X-axis direction at a position in the Y2 direction when viewed from the plurality of pressure chambers CV1 provided in the liquid ejection head 1B. That is to say, in the second embodiment, the situation where the piezoelectric body support region RS1 is arranged so as to surround the plurality of pressure chambers CV1 provided in the liquid ejection head 1 is envisaged.

[0156] In addition, the liquid ejection head 1B is different from the liquid ejection head 1 according to the first embodiment in that a piezoelectric element PZ-B1 is provided instead of the piezoelectric element PZ1. The piezoelectric element PZ-B1 is different from the piezoelectric element PZ1 according to the first embodiment in that a piezoelectric body QmB is provided instead of the piezoelectric body Qm. In addition, the piezoelectric structure 27B is different from the piezoelectric structure 27 according to the first embodiment in that an auxiliary electrode Hx21 laminated on the piezoelectric body support region RS1 and an auxiliary electrode Hx31 laminated on the auxiliary electrode HC1 are provided. In addition, the piezoelectric structure 27B is different from the piezoelectric structure 27 according to the first embodiment in that an auxiliary electrode LBB1 is provided instead of the auxiliary electrode LB1. The auxiliary electrode LBB1 is laminated on the common electrode QB1, the piezoelectric body QmB, the auxiliary electrode Hx11, the auxiliary electrode Hx21 provided on the piezoelectric body support region RS1, the auxiliary electrode Hx31, the auxiliary electrode Hx41 provided on the outer edge region RG1 of the piezoelectric body, and the auxiliary electrode HC1. In addition, the auxiliary electrode LBB1 only needs to be laminated on at least a part of the common electrode QB1 provided on the piezoelectric body drive region RK1 and at least a part of the auxiliary electrode Hx21 provided on the piezoelectric body support region RS1. The auxiliary electrode LBB1 is formed of a conductive material such as gold (Au) in the same manner as the auxiliary electrode LB1.

[0157] In addition, it is assumed that the liquid ejection head 1B has a substantially bilaterally symmetric structure with a plane having the X-axis direction as the normal direction as a symmetric plane. Specifically, the liquid ejection head 1B includes a piezoelectric body support region RS2 as an element symmetric to the piezoelectric body support region RS1, a piezoelectric element PZ-B2 as an element symmetric to the piezoelectric element PZ-B1, and an auxiliary electrode LBB2 as an element symmetric to the auxiliary electrode LBB1 corresponding to the nozzle row Ln2. Hereinafter, the piezoelectric body support region RS1 and the piezoelectric body support region RS2 may be collectively referred to as the piezoelectric body support region RS, the piezoelectric element PZ-B1 and the piezoelectric element PZ-B2 may be collectively referred to as the piezoelectric element PZ-B, and the auxiliary electrode LBB1 and the auxiliary electrode LBB2 may be collectively referred to as the auxiliary electrode LBB.

[0158] B.2. Conclusion of the Second Embodiment

[0159] As described above, the liquid ejection head 1B according to the second embodiment is characterized by including: a pressure chamber substrate 23 provided with a plurality of pressure chambers CV including a pressure chamber CV1 extending in the X1 direction; a piezoelectric element PZ-B1 disposed at a position in the Z2 direction when viewed from the pressure chamber substrate 23 corresponding to the pressure chamber CV1, and including a piezoelectric body QmB, a common electrode QB, and a separate electrode QC; and a sealing substrate 25 provided with a recess OB1 for housing the piezoelectric element PZ-B1 and disposed at a position in the Z2 direction when viewed from the piezoelectric element PZ-B1. When the liquid ejection head 1B is viewed from above with respect to the Z1 direction, the piezoelectric body QmB has: a piezoelectric body driving region RK1 extending from a position overlapping the pressure chamber CV1 to a position overlapping a wall WA1 of two walls of the recess OB1 in the X1 direction; a piezoelectric body outer edge region RG1 overlapping a wall WB1 of two walls of the recess OB1 in the X1 direction; and a piezoelectric body supporting region RS1 overlapping the wall WB1 of two walls of the recess OB1 in the X1 direction. The piezoelectric body supporting region RS1 is located between the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 in the X1 direction and is provided so as to be separated from the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1.

[0160] Thus, according to the liquid ejection head 1B according to the second embodiment, since the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are provided separately, the possibility of foreign matter entering between the piezoelectric body QmB and the sealing substrate 25 can be reduced compared to the case where the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are continuously provided. Moreover, even when foreign matter enters between the piezoelectric body QmB and the sealing substrate 25, the possibility of the relative positional relationship between the piezoelectric body QmB and the sealing substrate 25 being changed due to the foreign matter can be reduced. Therefore, according to the second embodiment, as in the first embodiment, the variation in ejection characteristics caused by foreign matter entering between the piezoelectric body QmB and the sealing substrate 25 can be suppressed compared to the case where the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are continuously provided.

[0161] In addition, in the liquid ejection head 1B according to the second embodiment, since the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are provided separately, the degree of transmission of the vibration generated in the piezoelectric body driving region RK1 to the piezoelectric body outer edge region RG1 when the piezoelectric element PZ-B1 is driven by the driving signal Com can be reduced as compared with the case where the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are provided continuously. Therefore, according to the second embodiment, as in the first embodiment, the possibility of displacement of the pressure chamber substrate 23 caused by the vibration of the piezoelectric body outer edge region RG1 can be reduced, and further, the possibility of change in the volume and shape of the pressure chamber CV1 due to the displacement of the pressure chamber substrate 23 can be reduced.

[0162] In addition, in the liquid ejection head 1B according to the second embodiment, since the piezoelectric body QmB includes the piezoelectric body support region RS1, the pressure is more likely to be transmitted from the piezoelectric body QmB to the sealing substrate 25 as compared with the case where the piezoelectric body support region RS1 is not provided. Thus, reliable bonding in each bonding process can be achieved.

[0163] In addition, in the second embodiment, the X1 direction is an example of the "first direction", the pressure chamber CV1 is an example of the "first pressure chamber", the Z2 direction is an example of the "upper part", the common electrode QB is an example of the "upper electrode", the individual electrode QC is an example of the "lower electrode", the piezoelectric element PZ-B1 is an example of the "first piezoelectric element", the concave portion OB1 is an example of the "first concave portion", the sealing substrate 25 is an example of the "sealing plate", the piezoelectric body driving region RK1 is an example of the "first region", the piezoelectric body outer edge region RG1 is an example of the "second region", the piezoelectric body support region RS1 is an example of the "fifth region", the wall WA1 is an example of "one of the two walls of the first concave portion", and the wall WB1 is an example of "the other wall of the two walls of the first concave portion".

[0164] In addition, it may be configured such that the liquid ejection head 1B according to the second embodiment is characterized in that when the liquid ejection head 1 is viewed from above, the piezoelectric body support region RS1 overlaps with the end region Wt2 of the wall WB1 that is close to the end of the concave portion OB1.

[0165] Thus, in the liquid ejection head 1B according to the second embodiment, since the piezoelectric body support region RS1 and the end region Wt2 of the wall WB1 overlap, pressure is more likely to be transmitted from the piezoelectric body QmB to the sealing substrate 25 than in a manner where the piezoelectric body support region RS1 and the wall WB do not overlap, enabling reliable bonding in each bonding process.

[0166] In addition, it may be configured that the liquid ejection head 1B according to the second embodiment is characterized in that an auxiliary electrode LA1 containing Au is formed on the upper part of at least a part of the piezoelectric body drive region RK1, and an auxiliary electrode LBB1 containing Au is formed on the upper part of at least a part of the piezoelectric body support region RS1.

[0167] Therefore, the liquid ejection head 1B according to the second embodiment can lower the resistance of the common electrode QB1 provided on the piezoelectric body drive region RK1, thereby reducing the possibility of the potential of the common electrode QB1 changing from the desired potential. Thus, the liquid ejection head 1B according to the second embodiment can suppress a decrease in the ejection performance of the liquid ejection head 1B caused by the potential of the common electrode QB1 changing from the desired potential.

[0168] Further, in the second embodiment, the auxiliary electrode LA1 is an example of the "first conductive layer", and the auxiliary electrode LBB1 is an example of the "second conductive layer".

[0169] In addition, it may be configured that the liquid ejection head 1B according to the second embodiment is characterized in that an auxiliary layer Hy1 containing NiCr is formed on the upper part of at least a part of the piezoelectric outer edge region RG1.

[0170] Therefore, the liquid ejection head 1B according to the second embodiment can more easily bond the piezoelectric body QmB and the sealing substrate 25 with an adhesive than in a manner where no auxiliary layer Hy1 is provided on the piezoelectric outer edge region RG1.

[0171] In addition, it may be configured that the liquid ejection head 1B according to the second embodiment is characterized in that the width of the piezoelectric body drive region RK1 in the X1 direction is longer than the width of the piezoelectric outer edge region RG1 in the X1 direction, and the width of the piezoelectric outer edge region RG1 in the X1 direction is longer than the width of the piezoelectric body support region RS1 in the X1 direction.

[0172] Therefore, the liquid ejection head 1B according to the second embodiment can achieve a more secure bond between the piezoelectric body QmB and the sealing substrate 25 than in a manner where the width of the piezoelectric outer edge region RG1 in the X1 direction is shorter than the width of the piezoelectric body support region RS1 in the X1 direction.

[0173] In addition, it can also be set that the liquid ejection head 1B according to the second embodiment is characterized in that a plurality of pressure chambers CV include a plurality of pressure chambers CV1 arranged along the Y1 direction intersecting the X1 direction, and the piezoelectric body support region RS1 extends so as to surround the plurality of pressure chambers CV1.

[0174] Therefore, compared with the case where the liquid ejection head 1B according to the second embodiment and the piezoelectric body support region RS1 are only arranged on one side when observed from the plurality of pressure chambers CV1, in the process of bonding the actuator substrate AT-B including the piezoelectric body QmB and the sealing substrate 25, or in the process of bonding the actuator chip including the actuator substrate AT-B and the sealing substrate 25 and other components such as the communication plate 22, the pressure becomes easier to be transmitted from the piezoelectric body QmB to the sealing substrate 25, so that reliable bonding in each bonding process can be achieved.

[0175] In addition, in the second embodiment, the Y1 direction is an example of the second direction.

[0176] In addition, it can also be set that the liquid ejection head 1B according to the second embodiment is characterized in that the pressure chamber substrate 23 is provided with a throttle portion SB1 that defines the wall surface of the communication flow path BD1, where the communication flow path BD1 is a flow path that connects the communication flow path BC1 for supplying ink and the pressure chamber CV1, and has a smaller cross-sectional area than the communication flow path BC1 and the pressure chamber CV1. When the liquid ejection head 1B is observed from above, the piezoelectric body support region RS1 overlaps with the throttle portion SB1.

[0177] Therefore, compared with the case where the piezoelectric body support region RS1 and the throttle portion SB1 of the liquid ejection head 1B according to the second embodiment do not overlap, in the process of bonding the actuator substrate AT-B including the piezoelectric body QmB and the sealing substrate 25, or in the process of bonding the actuator chip including the actuator substrate AT-B and the sealing substrate 25 and other components such as the communication plate 22, the pressure becomes easier to be transmitted from the piezoelectric body QmB to the sealing substrate 25, so that reliable bonding in each bonding process can be achieved.

[0178] In addition, in the second embodiment, the ink is an example of "liquid", the communication flow path BC1 is an example of "supply chamber", and the communication flow path BD1 is an example of "communication port".

[0179] B. Modification

[0180] Each of the above-exemplified modes can be deformed in various ways. Hereinafter, specific deformation modes will be exemplified. Two or more modes arbitrarily selected from the following examples can be appropriately combined within a non-contradictory range.

[0181] Modification Example 1

[0182] The liquid ejecting device may also include a liquid ejection head 1C instead of the liquid ejection head 1 or the liquid ejection head 1B described above.

[0183] Figure 14 FIG. is a cross-sectional view of the liquid ejection head 1C when the liquid ejection head 1C according to this modification example is observed in a cross-section along the Y2 direction.

[0184] As Figure 14 shown, the liquid ejection head 1C is different from the liquid ejection head 1B according to the second embodiment in that it includes a piezoelectric structure 27C instead of the piezoelectric structure 27B. The piezoelectric structure 27C is different from the piezoelectric structure 27B according to the second embodiment in that it includes auxiliary electrodes Hx51, Hx61, HC11, HC12, and an auxiliary layer HC13, and does not include auxiliary electrodes Hx11, Hx31, Hx41, and HC1. The auxiliary electrodes HC11, HC12, and the auxiliary layer HC13 are formed of, for example, the same material as the individual electrode QC1. The auxiliary electrodes Hx51 and Hx61 are formed of, for example, the same material as the common electrode QB1. The auxiliary electrode HC11 is provided on the insulating layer 242 in a region including the piezoelectric body support region RS1. The auxiliary electrode HC12 is provided on the insulating layer 242 in the piezoelectric outer edge region RG1. The auxiliary layer HC13 is provided on the insulating layer 242 in the piezoelectric outer edge region RG1 in a state of being insulated from the auxiliary electrode HC12 at a position in the X1 direction when observed from the auxiliary electrode HC12. The auxiliary electrode Hx51 is provided on the auxiliary electrode HC11 between the piezoelectric body support region RS1 and the piezoelectric body drive region RK1. The auxiliary electrode Hx61 is provided on the auxiliary electrode HC11 between the piezoelectric body support region RS1 and the piezoelectric outer edge region RG1.

[0185] In this modification example, since the piezoelectric body drive region RK1 and the piezoelectric outer edge region RG1 are also provided separately, the degree of vibration generated in the piezoelectric body drive region RK1 when the piezoelectric element PZ - B1 is driven by the drive signal Com being transmitted to the piezoelectric outer edge region RG1 can be reduced as compared with the case where the piezoelectric body drive region RK1 and the piezoelectric outer edge region RG1 are continuously provided.

[0186] Modification Example 2

[0187] Although the serial liquid ejecting apparatus that reciprocates the housing 921 carrying the liquid ejecting head 1 or the liquid ejecting head 1B or the liquid ejecting head 1C in the X-axis direction has been exemplified in the first embodiment, the second embodiment, and the modification 1 described above, the present invention is not limited to such a mode. The liquid ejecting apparatus may also be a line-type liquid ejecting apparatus in which a plurality of nozzles N are distributed across the entire width of the medium PP.

[0188] Modification 3

[0189] The liquid ejecting apparatus exemplified in the first embodiment, the second embodiment, the modification 1, and the modification 2 described above can be used not only in equipment dedicated to printing but also in various equipment such as a facsimile apparatus and a copying machine. However, the use of the liquid ejecting apparatus of the present invention is not limited to printing. For example, a liquid ejecting apparatus that ejects a solution of a color material is used as a manufacturing apparatus for forming a color filter of a liquid crystal display device. In addition, a liquid ejecting apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus for forming wirings and electrodes of a wiring substrate.

[0190] Reference Signs

[0191] 1... liquid ejecting head; 1B... liquid ejecting head; 21... nozzle substrate; 22... communication plate; 23... pressure chamber substrate; 24... diaphragm; 25... sealing substrate; 26... flow path forming substrate; 27... piezoelectric structure; 27B... piezoelectric structure; CV1... pressure chamber; CV2... pressure chamber; OB1... recess; OB2... recess; PZ1... piezoelectric element; PZ2... piezoelectric element; PZ-B1... piezoelectric element; Qm... piezoelectric body; QmB... piezoelectric body; RG1... piezoelectric outer edge region; RG2... piezoelectric outer edge region; RK1... piezoelectric body driving region; RK2... piezoelectric body driving region; RS1... piezoelectric body supporting region; WA1... wall; WB1... wall.

Claims

1. A liquid ejection head, characterized in that, Comprising: A pressure chamber substrate provided with a plurality of pressure chambers including a first pressure chamber and a second pressure chamber, wherein the first pressure chamber extends in a first direction, and the second pressure chamber is disposed at a position different from the first pressure chamber in the first direction and extends in the first direction; A plurality of piezoelectric elements configured above the pressure chamber substrate and including a piezoelectric body, an upper electrode, and a lower electrode; A sealing plate provided with a first recess and a second recess and configured above the plurality of piezoelectric elements, wherein the first recess houses a first piezoelectric element corresponding to the first pressure chamber among the plurality of piezoelectric elements, and the second recess houses a second piezoelectric element corresponding to the second pressure chamber among the plurality of piezoelectric elements, When the liquid ejection head is viewed from above with respect to the vertical direction, the piezoelectric body has: A first region overlapping with the first pressure chamber; A second region overlapping with one of the two walls of the first recess in the first direction; A third region overlapping with the second pressure chamber; A fourth region overlapping with one of the two walls of the second recess in the first direction, The first region is located between the second region and the third region in the first direction and is disposed so as to be separated from the second region, The third region is located between the first region and the fourth region in the first direction and is disposed so as to be separated from the fourth region.

2. The liquid ejection head according to claim 1, wherein: When the liquid ejection head is viewed from above, the first region overlaps with the other of the two walls of the first recess in the first direction.

3. The liquid ejection head according to claim 2, wherein: A conductive layer containing Au is formed above at least a part of the first region.

4. The liquid ejection head according to claim 2, wherein: An auxiliary layer containing NiCr is formed above at least a part of the second region.

5. The liquid ejection head according to claim 1, wherein: The width of the first region in the first direction is longer than the width of the second region in the first direction.

6. The liquid ejection head according to claim 1, wherein: The second region has: A first partial region overlapping with the plurality of pressure chambers when the second region is observed in the first direction; A second partial region not overlapping with the plurality of pressure chambers when the second region is observed in the first direction, The width of the first partial region in the first direction is longer than the width of the second partial region in the first direction.

7. The liquid ejection head according to claim 1, wherein: The plurality of pressure chambers include a plurality of first pressure chambers arranged and configured along a second direction intersecting the first direction, The second region has a first extension region extending in the first direction and a second extension region extending in the second direction. The first extension region has a first extended partial region which overlaps with the plurality of first pressure chambers when the first extension region is observed along the second direction. The second extension region has a second extended partial region which overlaps with the plurality of first pressure chambers when the second extension region is observed along the first direction. The width of the second extended partial region in the first direction is longer than the width of the first extended partial region in the second direction.

8. A liquid ejection device, characterized in that: It includes the liquid ejection head according to any one of claims 1 to 7.

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