Liquid ejecting head and liquid ejecting apparatus

Abstract

To inhibit foreign objects from entering a space between a piezoelectric body and a sealing plate.SOLUTION: A liquid ejection head includes: a pressure chamber substrate in which a plurality of pressure chambers including first pressure chambers extending in a first direction are provided; first piezoelectric elements disposed on an upper part of the pressure chamber substrate in such a way as to correspond to the first pressure chambers and each including a piezoelectric body, an upper electrode, and a lower electrode; and a sealing plate provided with a first recessed part for housing the first piezoelectric elements, the sealing plate disposed above the first piezoelectric elements. When the liquid ejecting head is planarly viewed with respect to a vertical direction, the piezoelectric body has: a first area extending from a position overlapping with the first pressure chamber to a position overlapping with one of two walls included in the first recessed part in the first direction; a second area overlapping with the other of the two walls included in the first recessed part in the first direction; and a fifth area overlapping with the other wall. In the first direction, the fifth area is located between the first area and the second area and is provided spaced apart from the first area and the second area.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head and a liquid ejection apparatus. [Background technology]

[0002] Liquid ejection heads that eject liquid such as ink are widely known. For example, Patent Document 1 discloses a liquid ejection head that includes a piezoelectric element including a piezoelectric body, an upper electrode, and a lower electrode, a pressure chamber that increases or decreases the internal pressure as the piezoelectric element is driven, a sealing plate that has a recess that accommodates the piezoelectric element, and a nozzle that ejects the liquid in the pressure chamber as the pressure in the pressure chamber increases. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-020407 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional technology, when the liquid ejection head is viewed in plan, the piezoelectric element is provided so as to extend widely over a range from an area overlapping with one wall of a recess provided in the sealing plate to an area overlapping with the other wall of the recess, in addition to an area overlapping with the pressure chamber. Therefore, with the conventional technology, vibrations caused by driving the piezoelectric element are transmitted to both walls of the recess via the piezoelectric element, which can change the relative positional relationship between the sealing plate and the piezoelectric element, or change the relative positional relationship between the pressure chamber substrate in which the pressure chamber is formed and the piezoelectric element. [Means for solving the problem]

[0005] In order to solve the above problems, the liquid ejection head of the present invention is a liquid ejection head comprising: a pressure chamber substrate provided with a plurality of pressure chambers including a first pressure chamber extending in a first direction; a first piezoelectric element arranged on the upper part of the pressure chamber substrate to correspond to the first pressure chamber, the first piezoelectric element including a piezoelectric body, an upper electrode, and a lower electrode; and a sealing plate arranged on the first piezoelectric element, the sealing plate having a first recess for accommodating the first piezoelectric element, wherein, when the liquid ejection head is viewed in a plan view in the vertical direction, the piezoelectric body has a first region extending from a position overlapping with the first pressure chamber to a position overlapping with one of two walls of the first recess in the first direction, a second region overlapping with the other of the two walls of the first recess in the first direction, and a fifth region overlapping with the other wall, the fifth region being located between the first region and the second region in the first direction and being spaced apart from the first region and the second region.

[0006] Furthermore, a liquid ejection device according to the present invention is a liquid ejection head comprising: a pressure chamber substrate provided with a plurality of pressure chambers including a first pressure chamber extending in a first direction; a first piezoelectric element arranged on the upper part of the pressure chamber substrate to correspond to the first pressure chamber, the first piezoelectric element including a piezoelectric body, an upper electrode, and a lower electrode; and a sealing plate arranged on the first piezoelectric element, the sealing plate having a first recess for accommodating the first piezoelectric element, wherein, when the liquid ejection head is viewed in a plan view in the vertical direction, the piezoelectric body has a first region extending from a position overlapping with the first pressure chamber to a position overlapping with one of two walls of the first recess in the first direction, a second region overlapping with the other of the two walls of the first recess in the first direction, and a fifth region overlapping with the other wall, the fifth region being located between the first region and the second region in the first direction and spaced apart from the first region and the second region. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a configuration diagram showing an example of a liquid ejection apparatus 100 according to a first embodiment of the present invention. [Figure 2] FIG. 1 is an exploded perspective view showing an example of the configuration of a liquid ejection head 1. [Figure 3] FIG. 1 is a cross-sectional view showing an example of the configuration of a liquid ejection head 1. [Figure 4] FIG. 1 is a cross-sectional view showing an example of the configuration of a liquid ejection head 1. [Figure 5] FIG. 1 is a cross-sectional view showing an example of the configuration of a liquid ejection head 1. [Figure 6] FIG. 2 is a plan view showing an example of the configuration of an actuator substrate AT. [Figure 7] 2 is a plan view showing an example of the configuration of a pressure chamber substrate 23. FIG. [Figure 8] 1 is a cross-sectional view showing an example of the configuration of a liquid ejection head 1Z according to Reference Example 1. FIG. [Figure 9] FIG. 10 is a plan view showing an example of the configuration of an actuator substrate AT-Z according to Reference Example 1. [Figure 10] 10 is a cross-sectional view showing an example of the configuration of a liquid ejection head 1W according to Reference Example 2. FIG. [Figure 11] FIG. 10 is a plan view showing an example of the configuration of an actuator substrate AT-W according to Reference Example 2. [Figure 12] FIG. 10 is a cross-sectional view showing an example of the configuration of a liquid ejection head 1B according to a second embodiment of the present invention. [Figure 13] FIG. 10 is a plan view showing an example of the configuration of an actuator substrate AT-B. [Figure 14] FIG. 10 is a cross-sectional view showing an example of the configuration of a liquid ejection head 1C according to a first modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, in each drawing, the dimensions and scale of each part are appropriately different from those of the actual parts. Furthermore, since the embodiments described below are preferred examples of the present invention, various technically preferable limitations are applied, but the scope of the present invention is not limited to these embodiments unless otherwise specified in the following description to the effect that the present invention is limited.

[0009] <<A. First Embodiment>> Hereinafter, the liquid discharge device 100 according to the first embodiment will be described.

[0010] <<A.1. Overview of the Liquid Discharge Device>> FIG. 1 is an explanatory diagram showing the liquid discharge device 100 according to the first embodiment.

[0011] The liquid discharge device 100 is an inkjet printing device that discharges ink onto the medium PP. The medium PP is typically printing paper, but any printing target such as a resin film or fabric can be used as the medium PP.

[0012] As shown in FIG. 1, the liquid discharge device 100 includes a plurality of liquid discharge heads 1, a control device 8, a transport mechanism 91, a moving mechanism 92, and a liquid container 93.

[0013] The liquid container 93 stores ink and supplies the stored ink to the liquid discharge head 1. As the liquid container 93, for example, a cartridge detachable from the liquid discharge device 100, a bag-shaped ink pack formed of a flexible film, or an ink tank capable of refilling ink can be adopted. A plurality of types of inks with different colors are stored in the liquid container 93. Note that ink is an example of "liquid".

[0014] The control device 8 includes, for example, a processing circuit such as a CPU or FPGA and a storage circuit such as a semiconductor memory, and controls each element of the liquid discharge device 100. Here, CPU is an abbreviation for Central Processing Unit, and FPGA is an abbreviation for Field Programmable Gate Array.

[0015] The conveying mechanism 91 conveys the medium PP in the Y1 direction along the Y-axis under the control of 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. Also, 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. Further, 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, the case where the X-axis, the Y-axis, and the Z-axis are orthogonal to each other will be assumed and described. However, the present invention is not limited to such a mode. The X-axis, the Y-axis, and the Z-axis only need to intersect each other.

[0016] The moving mechanism 92 reciprocates the plurality of liquid ejection heads 1 in the X1 direction and the X2 direction under the control of the control device 8. The moving mechanism 92 includes a storage case 921 that houses the plurality of liquid ejection heads 1 and an endless belt 922 to which the storage case 921 is fixed. Note that the liquid container 93 may be housed in the storage case 921 together with the liquid ejection head 1.

[0017] 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. Then, the liquid ejection head 1 is driven by the drive signal Com under the control of the control signal SI, and ejects ink in the Z1 direction from some or all of the plurality of nozzles N provided in the liquid ejection head 1. That is, the liquid ejection head 1 ejects ink from some or all of the plurality of nozzles N in conjunction with the conveyance of the medium PP by the conveyance mechanism 91 and the reciprocation of the liquid ejection head 1 by the moving mechanism 92, and lands the ejected ink on the surface of the medium PP, thereby forming a desired image on the surface of the medium PP. Note that the nozzles N will be described later in FIGS. 2 and 3.

[0018] <<A.2. Outline of Liquid Ejection Head>> Hereinafter, the outline of the liquid ejection head 1 will be described while referring to FIGS. 2 and 3.

[0019] FIG. 2 is an exploded perspective view of the liquid ejection head 1, and FIG. 3 is a cross-sectional view taken along line III-III in FIG.

[0020] 2 and 3, the liquid ejection head 1 includes a nozzle substrate 21, compliance sheets CS1 and CS2, a communication plate 22, a pressure chamber substrate 23, a vibration plate 24, a sealing substrate 25, a flow path forming substrate 26, and a piezoelectric structure 27 including a piezoelectric element PZ. Note that, hereinafter, the configuration including the vibration plate 24 and the piezoelectric structure 27 will be referred to as an actuator substrate AT. Also, hereinafter, the configuration including the actuator substrate AT, the sealing substrate 25, and the pressure chamber substrate 23 will be referred to as an actuator chip AC.

[0021] 2, the nozzle substrate 21 is a plate-like member that is long in the Y-axis direction and extends approximately parallel to the XY plane. In the first embodiment, it is assumed that the nozzle substrate 21 is manufactured by processing a silicon single crystal substrate using semiconductor manufacturing techniques such as etching, but any known material and manufacturing method may be used to manufacture the nozzle substrate 21.

[0022] In this specification, the term "substantially parallel" is a concept that includes not only cases where the two are completely parallel, but also cases where the two can be considered to be parallel when an error is taken into consideration. Specifically, the term "substantially parallel" is a concept that includes cases where the two can be considered to be parallel when an error of about 10% is taken into consideration. Furthermore, in this specification, expressions such as "substantially the same" are also terms that mean that the two can be considered to be "identical" when an error is taken into consideration, similar to "substantially parallel."

[0023] A plurality of nozzles N are formed on the nozzle substrate 21. Here, the nozzles N are through-holes provided in 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 arranged to extend in the Y-axis direction and a plurality of nozzles N2 arranged to extend in the Y-axis direction at positions in the X2 direction as viewed from the plurality of nozzles N1. Hereinafter, the plurality of nozzles N1 extending in the Y-axis direction will be referred to as a nozzle row Ln1, and the plurality of nozzles N2 extending in the Y-axis direction will be referred to as a nozzle row Ln2. Furthermore, hereinafter, the nozzle row Ln1 and the nozzle row Ln2 may be collectively referred to as a nozzle row Ln.

[0024] In the first embodiment, it is assumed that the components of the liquid ejection head 1 corresponding to the nozzle row Ln1 and the components of the nozzle row Ln2 are configured to be substantially symmetrical with respect to a plane having the X-axis direction as the normal direction. Therefore, the following description will focus on the components of the liquid ejection head 1 corresponding to the nozzle row Ln1, and will omit a description of the components of the liquid ejection head 1 corresponding to the nozzle row Ln2 as appropriate.

[0025] 2 and 3, a communicating plate 22 is provided at a position in the Z2 direction (above) as viewed from the nozzle substrate 21. The communicating plate 22 is a plate-shaped member that is long in the Y-axis direction and extends approximately parallel to the XY plane. In the first embodiment, it is assumed that the communicating plate 22 is manufactured by processing a silicon single crystal substrate using semiconductor manufacturing technology, but known materials and manufacturing methods may be arbitrarily adopted to manufacture the communicating plate 22.

[0026] Ink flow paths are formed in the communication plate 22. Specifically, a single supply flow path BA1 is formed in the communication plate 22, corresponding to the nozzle row Ln1, extending in the Y-axis direction. Furthermore, 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 in the communication plate 22, corresponding to the nozzle row Ln1. The connection flow path BK1 communicates with the supply flow path BA1 and is provided so as to extend in the Z-axis direction at a position in the X2 direction as viewed from the supply flow path BA1. The communication flow path BR1 is provided so as to extend in the Z-axis direction at a position in the X2 direction as viewed from the connection flow path BK1. The communication flow path BR1 communicates with the nozzle N1 corresponding to the communication flow path BR1.

[0027] In addition, in the communicating plate 22, one supply flow path BA2, which is an element symmetrical to one supply flow path BA1, a plurality of connection flow paths BK2, which are elements symmetrical to the plurality of connection flow paths BK1, and a plurality of communication flow paths BR2, which are elements symmetrical 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 supply flow paths BA, the connection flow paths BK1 and the connection flow paths BK2 may be collectively referred to as connection flow paths BK, and the communication flow paths BR1 and the communication flow paths BR2 may be collectively referred to as communication flow paths BR.

[0028] 2 and 3, a pressure chamber substrate 23 is provided at a position in the Z2 direction as viewed from the communication plate 22. The pressure chamber substrate 23 is a plate-shaped member that is long in the Y-axis direction and extends approximately parallel to the XY plane. In the first embodiment, it is assumed that the pressure chamber substrate 23 is manufactured by processing a silicon single crystal substrate using semiconductor manufacturing technology, but the pressure chamber substrate 23 may be manufactured using any known material and manufacturing method.

[0029] Ink flow paths are formed in the pressure chamber substrate 23. Specifically, the pressure chamber substrate 23 is formed with a plurality of pressure chambers CV1 corresponding to the plurality of nozzles N1, a plurality of communication flow paths BC1 (not shown in FIG. 2) corresponding to the plurality of nozzles N1, and a plurality of communication flow paths BD1 (not shown in FIG. 2) corresponding to the plurality of nozzles N1, in correspondence with the nozzle row Ln1. As shown in FIG. 3, the communication flow path BC1 communicates with the connection flow path BK1 and is provided so as to extend in the X-axis direction at a position in the Z2 direction as viewed from the connection flow path BK1. The communication flow path BD1 communicates with the communication flow path BC1 and is provided so as to extend in the X-axis direction at a position in the X2 direction as viewed from the communication flow path BC1. The pressure chamber CV1 connects the X2-direction end of the communication flow path BD1 and the X1-direction end of the communication flow path BR1, and is provided so as to extend in the X-axis direction.

[0030] In addition, a plurality of pressure chambers CV2, which are elements symmetrical to the plurality of pressure chambers CV1, a plurality of communicating channels BC2, which are elements symmetrical to the plurality of communicating channels BC1, and a plurality of communicating channels BD2, which are elements symmetrical to the plurality of communicating channels BD1, are formed in the pressure chamber substrate 23, corresponding to the nozzle row Ln2. Hereinafter, the pressure chambers CV1 and CV2 may be collectively referred to as pressure chambers CV, the communicating channels BC1 and BC2 may be collectively referred to as communicating channels BC, and the communicating channels BD1 and BD2 may be collectively referred to as communicating channels BD.

[0031] 2 and 3, a diaphragm 24 is provided at a position in the Z2 direction as viewed from the pressure chamber substrate 23. The diaphragm 24 is a plate-like member that is elongated in the Y-axis direction and extends substantially parallel to the XY plane, and is a member that can vibrate elastically.

[0032] As shown in FIGS. 2 and 3, a plurality of piezoelectric elements PZ1 corresponding to the plurality of pressure chambers CV1 are provided at positions in the Z2 direction as viewed from the vibration plate 24, corresponding to the nozzle row Ln1. The piezoelectric elements PZ1 are drive elements that deform in response to changes in the potential of the drive signal Com. In other words, the piezoelectric elements PZ1 are an example of energy conversion elements that convert the electrical energy of the drive signal Com into kinetic energy. Specifically, the piezoelectric elements PZ1 are driven and deformed in response to changes in the potential of the drive signal Com. The vibration plate 24 vibrates in conjunction with the deformation of the piezoelectric elements PZ1, and this vibration fluctuates the pressure within the pressure chambers CV1. As the pressure within the pressure chambers CV1 fluctuates, ink filled inside the pressure chambers CV1 is ejected from the nozzles N1 via the communication flow path BR1.

[0033] Note that a plurality of piezoelectric elements PZ2, which are elements symmetrical to the plurality of piezoelectric elements PZ1, are provided corresponding to the nozzle row Ln2 at positions in the Z2 direction as viewed from the vibration plate 24. Hereinafter, the piezoelectric elements PZ1 and PZ2 may be collectively referred to as the piezoelectric elements PZ.

[0034] 2 and 3, a sealing substrate 25 for protecting the plurality of piezoelectric elements PZ is provided at a position in the Z2 direction as viewed from the diaphragm 24. The sealing substrate 25 is a plate-like member that is elongated in the Y-axis direction and extends substantially parallel to the XY plane. In the first embodiment, it is assumed that the sealing substrate 25 is manufactured by processing a silicon single crystal substrate using semiconductor manufacturing technology, but the sealing substrate 25 may be manufactured using any known material and manufacturing method.

[0035] 2 and 3, the sealing substrate 25 has two surfaces whose normal direction is the Z-axis direction, and the surface in the Z1 direction has a recess OB1 that defines a sealed space SP1 for accommodating a plurality of piezoelectric elements PZ1, corresponding to the nozzle row Ln1. The sealed space SP1 is a space for sealing the piezoelectric elements PZ1 and preventing the piezoelectric elements PZ1 from being deteriorated by the influence of moisture, etc. Hereinafter, when the sealing substrate 25 is viewed in a plan view in the Z1 direction, of the two walls that the recess OB1 has in the X-axis direction, the wall located in the X2 direction will be referred to as wall WA1, and the wall located in the X1 direction will be referred to as wall WB1.

[0036] In addition, the sealing substrate 25 is provided with a recess OB2 that corresponds to the nozzle row Ln2 and has a wall WA2 that is an element symmetrical to the wall WA1 and a wall WB2 that is an element symmetrical to the wall WB1, and that defines a sealed space SP2 that is an element symmetrical to the sealed space SP1. Hereinafter, the sealed spaces SP1 and SP2 may be collectively referred to as a sealed space SP, the recesses OB1 and OB2 may be collectively referred to as a recess OB, the walls WA1 and WA2 may be collectively referred to as a wall WA, and the walls WB1 and WB2 may be collectively referred to as a wall WB.

[0037] Further, the sealing substrate 25 is provided with a through hole 250. When the sealing substrate 25 is viewed in the Z1 direction, the through hole 250 is located between the sealed space SP1 and the sealed space SP2, and is a hole that penetrates from the Z1 direction surface of the sealing substrate 25 to the Z2 direction surface of the sealing substrate 25. The wiring substrate 4 is inserted into the through hole 250.

[0038] 2 and 3, a flow path forming substrate 26 is provided at a position in the Z2 direction as viewed from the communicating plate 22. The flow path forming substrate 26 is a plate-like member that is elongated in the Y-axis direction and extends substantially parallel to the XY plane. In the first embodiment, it is assumed that the flow path forming substrate 26 is formed by injection molding of a resin material, but the flow path forming substrate 26 may be manufactured using any known material and method.

[0039] An ink flow channel is formed in the flow channel forming substrate 26. Specifically, the flow channel forming substrate 26 is provided with one supply channel BB1 and one inlet HL1 corresponding to the nozzle row Ln1. The supply channel BB1 communicates with the supply channel BA1 and is provided so as to extend in the Y-axis direction at a position in the Z2 direction as viewed from the supply channel BA1. The inlet HL1 communicates with the supply channel BB1. Ink is supplied to the supply channel BB1 from the liquid container 93 via the inlet HL1. The ink supplied to the supply channel BB1 from the liquid container 93 via the inlet HL1 flows into the supply channel BA1. Some of the ink that flows into the supply channel BA1 passes through the connecting channel BK1 and fills the pressure chamber CV1. When the piezoelectric element PZ1 is driven by the drive signal Com, some of the ink filling the pressure chamber CV1 passes through the connecting channel BR1 and is ejected from the nozzle N1.

[0040] In addition, a supply flow path BB2, which is an element symmetrical to the supply flow path BB1, and an inlet HL2, which is an element symmetrical to the inlet HL1, are provided in the flow path forming substrate 26, corresponding to the nozzle row Ln2. Hereinafter, the supply flow path BB1 and the supply flow path BB2 may be collectively referred to as supply flow paths BB, and the inlet HL1 and the inlet HL2 may be collectively referred to as inlet HL.

[0041] Furthermore, a through hole 260 is provided in the flow path forming substrate 26. When the flow path forming substrate 26 is viewed in the Z1 direction, the through hole 260 is located between the supply flow path BB1 and the supply flow path BB2, and is a hole that penetrates from the Z1 direction surface of the flow path forming substrate 26 to the Z2 direction surface of the flow path forming substrate 26. The wiring substrate 4 is inserted into the through hole 260.

[0042] As shown in FIGS. 2 and 3, a wiring board 4 is mounted on the surface of the actuator substrate AT in the Z2 direction, which includes a diaphragm 24 and a piezoelectric structure 27. The wiring board 4 is a component for electrically connecting the liquid ejection head 1 to the control device 8. As the wiring board 4, for example, a flexible wiring board such as an FPC or an FFC is preferably adopted. 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 an electric circuit that switches whether to supply a drive signal Com to the piezoelectric element PZ under the control of a control signal SI.

[0043] As shown in FIGS. 2 and 3, at a position in the Z1 direction when viewed from the communication board 22, corresponding to the nozzle row Ln1, a compliance sheet CS1 is provided so as to block the supply flow path BA1 and the connection flow path BK1. The compliance sheet CS1 is a plate-like member that is long in the Y-axis direction and extends substantially parallel to the XY plane. The compliance 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.

[0044] Note that a compliance sheet CS2, which is an element symmetric to the compliance sheet CS1, is provided in the liquid ejection head 1 corresponding to the nozzle row Ln2. Hereinafter, the compliance sheet CS1 and the compliance sheet CS2 may be collectively referred to as the compliance sheet CS.

[0045] <<A.3. Structure of Liquid Ejection Head>> Hereinafter, the structure of the liquid ejection head 1 will be described while referring to FIGS. 4 to 7.

[0046] Fig. 4 is a cross-sectional view of the liquid ejection head 1 taken in the Y2 direction, in the vicinity of piezoelectric element PZ1 of the liquid ejection head 1. Fig. 5 is a cross-sectional view of the liquid ejection head 1 taken in the Y2 direction, in the vicinity of piezoelectric element PZ2 of the liquid ejection head 1. Note that for simplicity, Figs. 4 and 5 are drawn to different scales in the X-axis direction, and the actual scale may correspond to, for example, Fig. 3. For example, Fig. 4 illustrates the width of pressure chamber CV1 in the X-axis direction as being approximately the same as the sum of the widths of communicating flow channel BC1 and communicating flow channel BD1 in the X-axis direction, but in reality, as shown in Fig. 3, pressure chamber CV1 is larger.

[0047] 4 and 5, as described above, the liquid ejection head 1 includes the communication plate 22, the pressure chamber substrate 23, the vibration plate 24, the piezoelectric structure 27, and the sealing substrate 25. As described above, the configuration including the vibration plate 24 and the piezoelectric structure 27 is referred to as the actuator substrate AT, and the configuration including the actuator substrate AT, the pressure chamber substrate 23, and the sealing substrate 25 is referred to as the actuator chip AC.

[0048] 4 and 5, 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 an elastic film made of silicon oxide such as silicon dioxide (SiO2). The insulating layer 242 is an insulating layer made of zirconium oxide such as zirconium dioxide (ZrO2). The piezoelectric structure 27 is formed on the insulating layer 242.

[0049] As shown in Figure 4, the piezoelectric structure 27 corresponds to the nozzle row Ln1 and includes a plurality of piezoelectric elements PZ1 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 common to the plurality of nozzles N1, one common electrode QB1 common to the plurality of nozzles N1, one auxiliary electrode LA1 common to the plurality of nozzles N1, one auxiliary electrode LB1 common to the plurality of nozzles N1, one auxiliary electrode HC1 common to the plurality of nozzles N1, one auxiliary electrode Hx11 common to the plurality of nozzles N1, one auxiliary electrode Hx41 common to the plurality of nozzles N1, and one auxiliary layer Hy1 common to the plurality of nozzles N1.

[0050] As described above, the liquid ejection head 1 includes a plurality of piezoelectric elements PZ1 corresponding to the plurality of nozzles N1. The piezoelectric element PZ1 is a laminated body in which a piezoelectric body Qm is interposed between an individual electrode QC1 and a common electrode QB1. Specifically, when the liquid ejection head 1 is viewed from above in the Z1 direction, the piezoelectric element PZ1 is a portion where the individual electrode QC1, the common electrode QB1, and the piezoelectric body Qm overlap. In the first embodiment, as an example, it is assumed that the piezoelectric body Qm is provided in the piezoelectric element PZ1 at a position in the Z2 direction as viewed from the individual electrode QC1, and the common electrode QB1 is provided at a position in the Z2 direction as viewed from the piezoelectric body Qm. However, it is also possible that the piezoelectric body Qm is provided in the piezoelectric element PZ1 at a position in the Z1 direction as viewed from the individual electrode QC1, and the common electrode QB1 is provided at a position in the Z1 direction as viewed from the piezoelectric body Qm.

[0051] The individual electrode QC1 is formed of a conductive material such as platinum (Pt) or iridium (Ir), etc. The individual electrode QC1 is laminated on the diaphragm 24.

[0052] The piezoelectric body Qm is made of a piezoelectric material such as lead zirconate titanate (Pb(Zr,Ti)O3). Hereinafter, the portion of the piezoelectric body Qm that constitutes the multiple piezoelectric elements PZ1 will be referred to as the piezoelectric body driving region RK1, and the portion that is spaced apart from the piezoelectric body driving region RK1 in the X1 direction as viewed from the piezoelectric body driving region RK1 will be referred to as the piezoelectric body outer edge region RG1. The piezoelectric driving region RK1 is laminated on the individual electrode QC1. When the liquid ejection head 1 is viewed in a plane in the Z1 direction, the piezoelectric driving region RK1 is provided at a position where at least a portion of the piezoelectric driving region RK1 overlaps with at least a portion of the pressure chamber CV1 and also overlaps with at least a portion of the wall WA1. The piezoelectric outer edge region RG1 is laminated on the auxiliary electrode HC1. When the liquid ejection head 1 is viewed in a plan view in the Z1 direction, the piezoelectric outer edge region RG1 is provided at a position where at least a part of the piezoelectric outer edge region RG1 overlaps with at least a part of the wall WB1.

[0053] In the first embodiment, as an example, it is assumed that the piezoelectric body Qm is provided so that the width of the piezoelectric body driving 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.

[0054] The common electrode QB1 is made of a conductive material such as platinum (Pt) or iridium (Ir), etc. The common electrode QB1 is laminated on the piezoelectric body driving region RK1 of the piezoelectric body Qm.

[0055] The auxiliary electrode HC1 is made 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 arranged so as to be insulated from the individual electrode QC1. The individual wiring LC1 is made of a conductive material such as gold (Au). The individual wiring LC1 is laminated on the insulating layer 242, the individual electrode QC1, and the piezoelectric element driving region RK1. The individual wiring LC1 is electrically connected to the individual electrode QC1 and supplies a drive signal Com, supplied from the control device 8, to the individual electrode QC1. Note that in the first embodiment, it is assumed that the individual wiring LC1 is laminated directly on the individual electrode QC1, thereby electrically connecting the individual wiring LC1 and the individual electrode QC1, but the present invention is not limited to this. 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 element driving region RK1 of the piezoelectric element Qm. The auxiliary electrode LA1 is made of a conductive material such as gold (Au), and is stacked on the common electrode QB1. The auxiliary electrode LA1 is electrically connected to the common electrode QB1. The auxiliary electrode Hx11 is made of the same conductive material as the common electrode QB1 and is stacked on the auxiliary electrode HC1. The auxiliary electrode Hx11 is electrically connected to the common electrode QB1 and is insulated from the individual electrode QC1. The auxiliary electrode Hx41 is made of the same conductive material as the common electrode QB1 and is laminated on the piezoelectric outer edge region RG1. The auxiliary electrode Hx41 is electrically connected to the common electrode QB1 and is insulated from the individual electrode QC1. The auxiliary electrode LB1 is made of a conductive material such as gold (Au), and is stacked on the common electrode QB1, the auxiliary electrode HC1, the auxiliary electrode Hx11, and the auxiliary electrode Hx41, and electrically connects the common electrode QB1 to the auxiliary electrode HC1, the auxiliary electrode Hx11, and the auxiliary electrode Hx41.

[0056] The auxiliary layer Hy1 is made of a conductive material such as nichrome (NiCr). However, the auxiliary layer Hy1 may also be made of a non-conductive material. The auxiliary layer Hy1 is laminated on the piezoelectric body outer edge region RG1. The auxiliary layer Hy1 is arranged so as to be insulated from the individual electrode QC1 and the common electrode QB1.

[0057] 4, the piezoelectric structure 27 includes an adhesive layer 50. The adhesive layer 50 is made of an adhesive. The adhesive layer 50 bonds the individual wiring LC1, the piezoelectric driving region RK1, and the auxiliary electrode LA1 to a wall WA1 of the sealing substrate 25. The adhesive layer 50 also bonds the auxiliary electrode LB1, the piezoelectric outer edge region RG1, and the auxiliary layer Hy1 to a wall WB1 of the sealing substrate 25.

[0058] As shown in Figure 5, the piezoelectric structure 27 corresponds to the nozzle row Ln2 and includes a plurality of piezoelectric elements PZ2 which are symmetrical elements to the plurality of piezoelectric elements PZ1, a plurality of individual wirings LC2 which are symmetrical elements to the plurality of individual wirings LC1, a plurality of individual electrodes QC2 which are symmetrical elements to the plurality of individual electrodes QC1, one piezoelectric body Qm, one common electrode QB2 which is symmetrical element to the common electrode QB1, one auxiliary electrode LA2 which is symmetrical element to the auxiliary electrode LA1, one auxiliary electrode LB2 which is symmetrical element to the auxiliary electrode LB1, one auxiliary electrode HC2 which is symmetrical element to the auxiliary electrode HC1, one auxiliary electrode Hx12 which is symmetrical element to the auxiliary electrode Hx11, one auxiliary electrode Hx42 which is symmetrical element to the auxiliary electrode Hx41, and one auxiliary layer Hy2 which is symmetrical element to the auxiliary layer Hy1. Furthermore, the piezoelectric body Qm corresponds to the nozzle row Ln2 and includes a piezoelectric body driving region RK2 that is an element symmetrical to the piezoelectric body driving region RK1, and a piezoelectric body outer edge region RG2 that is an element symmetrical to the piezoelectric body outer edge region RG1. In the following, individual wiring LC1 and individual wiring LC2 may be collectively referred to as individual wiring LC, individual electrodes QC1 and individual electrodes QC2 may be collectively referred to as individual electrodes QC, common electrodes QB1 and common electrodes QB2 may be collectively referred to as common electrodes QB, auxiliary electrodes LA1 and auxiliary electrodes LA2 may be collectively referred to as auxiliary electrodes LA, auxiliary electrodes LB1 and auxiliary electrodes LB2 may be collectively referred to as auxiliary electrodes LB, auxiliary electrodes HC1 and auxiliary electrodes HC2 may be collectively referred to as auxiliary electrodes HC, auxiliary electrodes Hx11 and auxiliary electrodes Hx12 may be collectively referred to as auxiliary electrode Hx1, auxiliary electrodes Hx41 and auxiliary electrodes Hx42 may be collectively referred to as auxiliary electrode Hx4, auxiliary layers Hy1 and auxiliary layers Hy2 may be collectively referred to as auxiliary layers Hy, piezoelectric driving regions RK1 and piezoelectric driving regions RK2 may be collectively referred to as piezoelectric driving regions RK, and piezoelectric outer edge regions RG1 and piezoelectric outer edge regions RG2 may be collectively referred to as piezoelectric outer edge regions RG.

[0059] 4, as described above, the sealing substrate 25 is provided with a recess OB1 that defines a sealing space SP1 for accommodating a plurality of piezoelectric elements PZ1, corresponding to the nozzle row Ln1. Furthermore, the sealing substrate 25 is provided with a groove ON1 in the wall WB1, corresponding to the nozzle row Ln1, for accommodating excess adhesive of the adhesive contained in the adhesive layer 50.

[0060] 5, as described above, the sealing substrate 25 is provided with a recess OB2, which is an element symmetrical to the recess OB1, and a groove portion ON2, which is an element symmetrical to the groove portion ON1, corresponding to the nozzle row Ln2. Hereinafter, the groove portion ON1 and the groove portion ON2 may be collectively referred to as the groove portion ON.

[0061] Fig. 6 is a plan view of the actuator substrate AT provided in the liquid ejection head 1 when viewed in plan in the Z1 direction. In Fig. 6, in addition to the actuator substrate AT including the vibration plate 24 and the piezoelectric element Qm, the sealing substrate 25 provided at a position (above) in the Z2 direction as viewed from the actuator substrate AT, and a plurality of pressure chambers CV provided at a position (below) in the Z1 direction as viewed from the actuator substrate AT are indicated by dashed lines.

[0062] As described above, the actuator substrate AT has the diaphragm 24 and the piezoelectric body Qm laminated on the diaphragm 24.

[0063] 6, as described above, the piezoelectric body Qm has a piezoelectric body driving region RK1 that extends in the Y-axis direction in correspondence with the nozzle row Ln1. When the liquid ejection head 1 is viewed from above, the piezoelectric body driving region RK1 is provided so as to overlap with the multiple pressure chambers CV1 and at least a portion of the wall WA1. It should be noted that the piezoelectric body driving region RK1 is provided with a plurality of openings KK1. The openings KK1 are through-holes that penetrate the piezoelectric body driving region RK1 in the Z-axis direction. When the liquid ejection head 1 is viewed in a plan view, each opening KK1 is provided in the piezoelectric body driving region RK1 between two adjacent pressure chambers CV1 among the plurality of pressure chambers CV1. Because the piezoelectric body driving region RK1 is provided with 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 prevent vibrations caused by the drive from propagating to the piezoelectric element PZ1 corresponding to the other of the two adjacent pressure chambers CV1. Furthermore, it has been found that the boundary between the piezoelectric body Qm's active portion (piezoelectric body driving region RK1) and its adjacent inactive portion in the X2 direction is prone to damage to the piezoelectric body with use. Because the moving and non-moving portions of the piezoelectric body Qm are adjacent to each other when driven, the difference in strain of the piezoelectric body Qm increases, leading to damage. To mitigate this, in this embodiment, the boundary is positioned so that it overlaps with the wall WA1 when the liquid ejection head 1 is viewed from above, and the wall WA1 presses against the boundary. This reduces the movement of the portion of the piezoelectric body driving region RK1 that overlaps with the wall WA1, thereby reducing the damage. To achieve this configuration, as described above, a portion of the piezoelectric body driving region RK1 is positioned so that it overlaps with the wall WA when viewed from above. Even in a position overlapping with wall WA1 in plan view, if the piezoelectric element Qm is provided at a distance from the piezoelectric element drive region RK1, as in the position overlapping with wall WB1 in plan view described below, it is possible to achieve the effects of reducing foreign matter contamination, sealing performance due to vibration transmission, and suppressing degradation of ejection characteristics. However, the wall WA1 side is more susceptible to damage at the boundary between the active and inactive parts during use than the wall WB1 side. This is thought to be due to the fact that the wall WA1 side is closer to the nozzle N1, which could prevent ejection itself if damage occurs, and because the drive signal Com is applied to the individual electrode QC1 from the wall WA1 side, the voltage drop is smaller on the wall WA1 side than on the wall WB1, making it more likely to receive a large voltage. Therefore, in this embodiment, we prioritized reducing damage during use on the wall WA1 side, so a portion of the piezoelectric element drive region RK1 overlaps with wall WA in plan view.

[0064] As described above, the piezoelectric element Qm has a piezoelectric element driving region RK2 that corresponds to the nozzle row Ln2 and is an element symmetrical to the piezoelectric element driving region RK1. The piezoelectric element driving region RK2 has a plurality of openings KK2 that are elements symmetrical to the plurality of openings KK1.

[0065] 6, the piezoelectric body Qm has a piezoelectric body outer edge region RG1 corresponding to the nozzle row Ln1. When the liquid ejection head 1 is viewed from above, the piezoelectric body outer edge region RG1 overlaps with at least a portion of the wall WB1 and is spaced apart from the piezoelectric body driving region RK1.

[0066] The piezoelectric outer edge region RG1 has an extending portion RGy extending in the Y-axis direction at a position in the X1 direction as viewed from the piezoelectric drive region RK1, and two extending portions RGx extending in the X-axis direction at positions in the Y1 direction and the Y2 direction as viewed from the piezoelectric drive region RK1. The extending portion RGy has a central portion RGm that overlaps with the pressure chambers CV1 when viewed from the liquid ejection head 1 in the X-axis direction, and end portions RGs that do not overlap with the pressure chambers CV1 when viewed from the liquid ejection head 1 in the X-axis direction. In the first embodiment, as an example, it is assumed that the piezoelectric outer edge region RG1 is provided so 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. In the first embodiment, as an example, it is assumed that the piezoelectric outer edge region RG1 is provided so that the width of the central portion RGm in the X-axis direction is longer than the width of the extending portion RGx in the Y-axis direction.

[0067] As described above, the piezoelectric element Qm has a piezoelectric element outer edge region RG2 that corresponds to the nozzle row Ln2 and is an element symmetrical to the piezoelectric element outer edge region RG1. The piezoelectric element outer edge region RG2 has an extension portion RGy and an extension portion RGx.

[0068] 6, the piezoelectric body Qm has a piezoelectric body central region RP1 that extends in the Y-axis direction in correspondence with the nozzle row Ln1. The piezoelectric body central region RP1 is provided so as to overlap with the wiring substrate 4 when the liquid ejection head 1 is viewed in plan. A conductive wiring (not shown) is provided above the piezoelectric body central region RP1 to electrically connect the wiring provided on the wiring substrate 4 and the individual wiring LC.

[0069] Also, as described above, the piezoelectric body Qm includes a piezoelectric body central region RP2, which is an element symmetric to the piezoelectric body central region RP1, corresponding to the nozzle row Ln2. Hereinafter, the piezoelectric body central region RP1 and the piezoelectric body central region RP2 may be collectively referred to as the piezoelectric body central region RP.

[0070] FIG. 7 is a plan view of the pressure chamber substrate 23 provided in the liquid discharge head 1, showing the vicinity of the pressure chamber CV1 in a plan view in the Z1 direction.

[0071] As shown in FIG. 7, in the pressure chamber substrate 23, a communication flow path BC1 and a communication flow path BD1 that communicate with the pressure chamber CV1 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 communicates with 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 the cross-sectional area of the pressure chamber CV1 and smaller than the cross-sectional area of the communication flow path BC1. For example, when the pressure chamber substrate 23 is viewed in a plan view 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. Note that a portion of the pressure chamber substrate 23 that defines the wall surface of the communication flow path BD1 is referred to as a throttle portion SB1.

[0072] Also, in the pressure chamber substrate 23, as described above, 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.

[0073] <<A.4. Reference Example>> Hereinafter, in order to clarify the characteristics of the liquid discharge head 1 according to the first embodiment, the liquid discharge head 1Z according to Reference Example 1 and the liquid discharge head 1W according to Reference Example 2 will be described.

[0074] Fig. 8 is a cross-sectional view of the liquid ejection head 1Z according to Reference Example 1 when viewed in the Y2 direction. Fig. 9 is a plan view of the actuator substrate AT-Z provided in the liquid ejection head 1Z when viewed in the Z1 direction.

[0075] 8 and 9, the liquid ejection head 1Z differs from the liquid ejection head 1 according to the first embodiment in that it includes a piezoelectric structure 27Z including a piezoelectric element QmZ instead of the piezoelectric structure 27 including the piezoelectric element Qm. The piezoelectric element QmZ differs from the piezoelectric element Qm according to the first embodiment in that it includes a piezoelectric element extending region RZ1 corresponding to the nozzle row Ln1 instead of the piezoelectric element driving region RK1 and the piezoelectric element outer edge region RG1.

[0076] 8 and 9, when the liquid ejection head 1Z is viewed in a plane in the Z1 direction, the piezoelectric element extending region RZ1 is provided in a range where at least a portion of the piezoelectric element extending region RZ1 overlaps with the pressure chamber CV1, where at least a portion of the piezoelectric element extending region RZ1 overlaps with at least a portion of the wall WA1, and where at least a portion of the piezoelectric element extending region RZ1 overlaps with at least a portion of the wall WB1. In other words, the piezoelectric element extending region RZ1 of the piezoelectric element QmZ is a region obtained by expanding the extension ranges of the piezoelectric element driving region RK1 and the piezoelectric element outer edge region RG1 of the piezoelectric element Qm, as in the conventional technology, so that the piezoelectric element driving region RK1 and the piezoelectric element outer edge region RG1 are connected into one.

[0077] Liquid ejection head 1Z also differs from liquid ejection head 1 according to the first embodiment in that it includes piezoelectric element PZ-Z1 instead of piezoelectric element PZ1. Piezoelectric element PZ-Z1 also differs from piezoelectric element PZ1 according to the first embodiment in that it includes piezoelectric body QmZ instead of piezoelectric body Qm. Piezoelectric structure 27Z also differs from piezoelectric structure 27 according to the first embodiment in that it includes auxiliary electrode LBZ1 laminated on piezoelectric body QmZ instead of auxiliary electrode LB1. Piezoelectric structure 27Z also differs from piezoelectric structure 27 according to the first embodiment in that it does not include auxiliary electrodes Hx11 and Hx41.

[0078] 8, the region of the piezoelectric element extending region RZ1 of the piezoelectric element QmZ that constitutes the piezoelectric element PZ-Z1 will be referred to as the piezoelectric element driving region RZK1. Also, hereinafter, the portion of the piezoelectric element extending region RZ1 that is located below the wall WB1 and supports the wall WB1 will be referred to as the piezoelectric element outer edge region RZG1. Also, hereinafter, the portion of the piezoelectric element extending region RZ1 between the piezoelectric element driving region RZK1 and the piezoelectric element outer edge region RZG1 will be referred to as the piezoelectric element connection region RZM1.

[0079] It is assumed that the liquid ejection head 1Z has a configuration that is approximately symmetrical with respect to a plane normal to the X-axis direction. Specifically, the liquid ejection head 1Z corresponds to the nozzle row Ln2 and includes a piezoelectric body extending region RZ2 that is an element symmetrical to the piezoelectric body extending region RZ1, a piezoelectric element PZ-Z2 that is an element symmetrical to the piezoelectric element PZ-Z1, and an auxiliary electrode LBZ2 that is an element symmetrical to the auxiliary electrode LBZ1. Hereinafter, the piezoelectric body extending region RZ1 and the piezoelectric body extending region RZ2 may be collectively referred to as the piezoelectric body extending region RZ, the piezoelectric elements PZ-Z1 and the piezoelectric elements PZ-Z2 may be collectively referred to as the piezoelectric elements PZ-Z, and the auxiliary electrodes LBZ1 and LBZ2 may be collectively referred to as the auxiliary electrodes LBZ.

[0080] Thus, in the liquid ejection head 1Z according to Reference Example 1, the piezoelectric body extending region RZ1 of the piezoelectric body QmZ includes a piezoelectric body driving 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 driving 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. In Reference Example 1, the piezoelectric body extending region RZ1 includes the piezoelectric body connection region RZM1 and has a wide area. Therefore, compared to an embodiment that does not include the piezoelectric body connection region RZM1, there is a higher possibility that foreign matter will be mixed in between the actuator substrate AT-Z and the sealing substrate 25 when the actuator substrate AT-Z includes the piezoelectric structure 27Z including the piezoelectric body QmZ and the sealing substrate 25 are bonded together with the adhesive layer 50. If foreign matter gets mixed in 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, the influence of the foreign matter may cause the piezoelectric element PZ-Z1 to be driven in a manner different from that specified by the drive signal Com. In other words, if foreign matter gets mixed in between the actuator substrate AT-Z and the sealing substrate 25, the influence of the foreign matter may cause a decrease in the ink ejection performance from the liquid ejection head 1Z.

[0081] In contrast, in the first embodiment, the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 included in the piezoelectric body Qm are spaced apart from each other. That is, according to the first embodiment, the piezoelectric body driving region RK1 located above the pressure chamber CV1 and constituting the piezoelectric element PZ1, and the piezoelectric body outer edge region RG1 located below the wall WB1, are spaced apart from each other. Therefore, according to the first embodiment, the area of the piezoelectric body Qm as viewed in the Z-axis direction can be reduced compared to Reference Example 1. As a result, according to the first embodiment, it is possible to reduce the possibility of foreign matter being mixed between the actuator substrate AT and the sealing substrate 25 compared to Reference Example 1, and it is possible to reduce the possibility of the ink ejection performance from the liquid ejection head 1 being degraded due to the influence of foreign matter mixed between the actuator substrate AT and the sealing substrate 25.

[0082] Furthermore, 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 driving region RZK1 of the piezoelectric extension region RZ1 of the piezoelectric element QmZ vibrates, the vibrations generated in the piezoelectric driving region RZK1 are transmitted to the piezoelectric outer edge region RZG1 via the piezoelectric connection region RZM1. In Reference Example 1, the vibrations transmitted to the piezoelectric outer edge region RZG1 displace 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. When the sealing substrate 25 is displaced, the sealing performance of the sealing space SP1 for the piezoelectric element PZ-Z1 deteriorates. Furthermore, when the pressure chamber substrate 23 is displaced, the volume and shape of the pressure chamber CV1 change, thereby deteriorating the ink ejection performance from the liquid ejection head 1Z. Thus, according to Reference Example 1, there is a high possibility that vibrations transmitted from the piezoelectric driving region RZK1 via the piezoelectric connection region RZM1 to the piezoelectric outer edge region RZG1 will result in a decrease in the sealing ability of the piezoelectric element PZ-Z1 and a decrease in the ejection performance of the liquid ejection head 1Z.

[0083] In contrast to this, in the first embodiment, as described above, the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are spaced apart, and therefore the degree to which vibrations generated in the piezoelectric body driving region RK1 when the piezoelectric element PZ1 is driven by the drive signal Com are transmitted to the piezoelectric body outer edge region RG1 can be reduced compared to Reference Example 1. Therefore, according to the first embodiment, it is possible to reduce deterioration in the sealing performance for the piezoelectric element PZ1 and also reduce deterioration in the ejection performance of the liquid ejection head 1 compared to Reference Example 1.

[0084] Fig. 10 is a cross-sectional view of the liquid ejection head 1W according to Reference Example 2 when viewed in the Y2 direction. Fig. 11 is a plan view of the actuator substrate AT-W provided in the liquid ejection head 1W when viewed in the Z1 direction.

[0085] 10 and 11, the liquid ejection head 1W differs from the liquid ejection head 1 according to the first embodiment in that it includes a piezoelectric structure 27W including a piezoelectric element QmW instead of the piezoelectric structure 27 including the piezoelectric element Qm. The piezoelectric element QmW differs from the piezoelectric element Qm according to the first embodiment in that it does not include a piezoelectric element outer edge region RG1 corresponding to the nozzle row Ln1. In other words, the piezoelectric element QmW includes a piezoelectric element driving region RK1 and a piezoelectric element central region RP1 corresponding to the nozzle row Ln1.

[0086] Liquid ejection head 1W also differs from liquid ejection head 1 according to the first embodiment in that it includes a piezoelectric element PZ-W1 instead of piezoelectric element PZ1. Piezoelectric element PZ-W1 also differs from piezoelectric element PZ1 according to the first embodiment in that it includes a piezoelectric body QmW instead of piezoelectric body Qm. Piezoelectric structure 27W also differs from piezoelectric structure 27 according to the first embodiment in that it includes an auxiliary electrode LBW1 laminated on piezoelectric body QmZ instead of auxiliary electrode LB1. Piezoelectric structure 27W also differs from piezoelectric structure 27 according to the first embodiment in that it does not include auxiliary electrodes Hx11, Hx41, and HC1.

[0087] It is assumed that the liquid ejection head 1W has a configuration that is approximately plane-symmetrical with respect to a plane normal to the X-axis direction. Specifically, the liquid ejection head 1W corresponds to the nozzle row Ln2 and is equipped with a piezoelectric element PZ-W2 that is an element symmetrical to the piezoelectric element PZ-W1, and an auxiliary electrode LBW2 that is an element symmetrical to the auxiliary electrode LBW1. Hereinafter, the piezoelectric elements PZ-W1 and PZ-W2 may be collectively referred to as piezoelectric element PZ-W, and the auxiliary electrodes LBW1 and LBW2 may be collectively referred to as auxiliary electrode LBW.

[0088] As described above, in the liquid ejection head 1W according to Reference Example 2, the piezoelectric body QmW has a piezoelectric body driving region RK1 having a smaller area than the piezoelectric body outer edge region RG1. Therefore, according to Reference Example 2, compared to an embodiment in which the liquid ejection head 1Z is provided with a piezoelectric body QmZ having a piezoelectric body outer edge region RZG1 with a larger area, as in Reference Example 1, it is possible to reduce the possibility of foreign matter getting mixed in between the actuator substrate AT-W and the sealing substrate 25 when bonding the actuator substrate AT-W and the sealing substrate 25 with the adhesive layer 50.

[0089] 10, in the piezoelectric structure 27W according to Reference Example 2, in addition to the adhesive layer 50 and the individual electrode QC1, the piezoelectric element QmW, the individual wiring LC1, and the auxiliary electrode LA1 are provided below the wall WA1, while only the adhesive layer 50 and the auxiliary layer Hy1 are provided below the wall WB1. That is, in Reference Example 2, the thickness of the adhesive layer 50 below the wall WA1 is different from the thickness of the adhesive layer 50 below the wall WB1. Therefore, compared to Reference Example 1, in Reference Example 2, the adhesion between the piezoelectric structure 27W and the sealing substrate 25 is weaker, and the strength of the actuator chip including the actuator substrate AT-W and the sealing substrate 25 is lower.

[0090] In contrast, in the first embodiment, the piezoelectric body Qm includes a piezoelectric outer edge region RG1 in addition to the piezoelectric drive region RK1. Further, in the first embodiment, the individual wiring LC1 and the auxiliary electrode LA1 are provided on the piezoelectric drive region RK1, and the auxiliary electrode LB1 is provided on the piezoelectric outer edge region RG1. Therefore, in the first embodiment, the thickness of the adhesive layer 50 at the lower part of the wall WA1 and the thickness of the adhesive layer 50 at the lower part of the wall WB1 can be made substantially the same. For this reason, compared with Reference Example 2, the first embodiment can improve the adhesion between the piezoelectric structure 27 and the sealing substrate 25, and thereby increase the strength of the actuator chip AC including the actuator substrate AT and the sealing substrate 25.

[0091] As described above, according to the first embodiment, it is possible to achieve both the reduction of the possibility of foreign matter mixing between the actuator substrate AT and the sealing substrate 25, the reduction of the possibility of deterioration of the sealing performance of the piezoelectric element PZ1 by the sealing substrate 25, and the securing of the strength of the actuator chip AC.

[0092] <<A.5. Conclusion of the First Embodiment>> As described above, the liquid ejection head 1 according to the first embodiment is a liquid ejection head 1 comprising: a pressure chamber substrate 23 in which a plurality of pressure chambers CV are provided, including a pressure chamber CV1 extending in the X1 direction and a pressure chamber CV2 that is provided at a position different from the pressure chamber CV1 in the X1 direction and extends in the X1 direction; and a sealing substrate 25 that is arranged in the Z2 direction as viewed from the pressure chamber substrate 23 and is provided with a plurality of piezoelectric elements PZ, each of which includes a piezoelectric body Qm, a common electrode QB, and an individual electrode QC, a recess OB1 that accommodates the piezoelectric element PZ1 of the plurality of piezoelectric elements PZ that corresponds to the pressure chamber CV1, and a recess OB2 that accommodates the piezoelectric element PZ2 of the plurality of piezoelectric elements PZ that corresponds to the pressure chamber CV2. When the liquid ejection head 1 is viewed in a plane in the Z1 direction, the electric body Qm has a piezoelectric body driving region RK1 that overlaps with the pressure chamber CV1, a piezoelectric body outer edge region RG1 that overlaps with wall WB1 of the two walls of the recess OB1 in the X1 direction, a piezoelectric body driving region RK2 that overlaps with the pressure chamber CV2, and a piezoelectric body outer edge region RG2 that overlaps with wall WB2 of the two walls of the recess OB2 in the X1 direction, and is characterized in that 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 spaced apart from the piezoelectric body outer edge region RG1, and 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 spaced apart from the piezoelectric body outer edge region RG2.

[0093] As described above, according to the liquid ejection head 1 of the first embodiment, the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are spaced apart, which reduces the possibility of foreign matter entering between the piezoelectric body Qm and the sealing substrate 25 compared to an embodiment in which the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are continuously provided, and further reduces the possibility that, even if foreign matter does enter between the piezoelectric body Qm and the sealing substrate 25, the relative positional relationship between the piezoelectric body Qm and the sealing substrate 25 will fluctuate due to the foreign matter. Therefore, according to the first embodiment, it is possible to suppress fluctuations in ejection characteristics due to foreign matter entering between the piezoelectric body Qm and the sealing substrate 25 compared to an embodiment in which the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are continuously provided. Furthermore, according to the first embodiment, compared to the aspect in which the piezoelectric driving region RK1 and the piezoelectric outer edge region RG1 are continuously arranged, it is possible to suppress fluctuations in the relative positional relationship between the piezoelectric body Qm and the sealing substrate 25 due to foreign matter mixed between the piezoelectric body Qm and the sealing substrate 25, and to suppress fluctuations in the ejection characteristics due to fluctuations in the relative positional relationship between the piezoelectric body Qm and the sealing substrate 25.

[0094] Furthermore, according to the liquid ejection head 1 of the first embodiment, the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are spaced apart from each other. This reduces the degree to which vibrations generated in the piezoelectric body driving region RK1 when the piezoelectric element PZ1 is driven by the drive signal Com are transmitted to the piezoelectric body outer edge region RG1, compared to an embodiment in which the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are continuously provided. Therefore, according to the first embodiment, compared to an embodiment in which the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are continuously provided, the possibility of displacement of the pressure chamber substrate 23 due to vibrations in the piezoelectric body outer edge region RG1 is reduced, and the possibility of fluctuations in the volume and shape of the pressure chamber CV1 due to displacement of the pressure chamber substrate 23 is reduced. As a result, according to the first embodiment, it is possible to suppress fluctuations in the ejection performance of the liquid ejection head 1 due to fluctuations in the volume and shape of the pressure chamber CV1, compared to an embodiment in which the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are continuously provided.

[0095] In the first embodiment, the X1 direction is an example of the "first direction," the Z2 direction is an example of the "upper," 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," and the recess OB2 is an example of a "second recess", the sealing substrate 25 is an example of a "sealing plate", the piezoelectric driving region RK1 is an example of a "first region", the piezoelectric outer edge region RG1 is an example of a "second region", the piezoelectric driving region RK2 is an example of a "third region", the piezoelectric outer edge region RG2 is an example of a "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".

[0096] Furthermore, in the first embodiment, the liquid ejection head 1 has components corresponding to the nozzle row Ln1 and components corresponding to the nozzle row Ln2, but the present invention is not limited to this. The liquid ejection head 1 may have components corresponding to one nozzle row Ln. That is, the liquid ejection head 1 according to the first embodiment is a liquid ejection head comprising: a pressure chamber substrate having a first pressure chamber extending in a first direction; a first piezoelectric element arranged on the upper part of the pressure chamber substrate and including a piezoelectric body, an upper electrode, and a lower electrode; and a sealing plate arranged on the upper part of the first piezoelectric element and having a first recess for accommodating the first piezoelectric element, wherein the piezoelectric body has a first region that overlaps with the first pressure chamber when the liquid ejection head is viewed in a plane in the vertical direction, and a second region that overlaps with one of two walls of the first recess in the first direction, and the first region is arranged spaced apart from the second region.

[0097] Furthermore, in the liquid ejection head 1 according to the first embodiment, the piezoelectric driving region RK1 may be characterized in that, when the liquid ejection head 1 is viewed in a plane, it overlaps with wall WA1, one of the two walls of the recess OB1, in the X1 direction.

[0098] In the first embodiment, the wall WA1 is an example of "the other of the two walls of the first recess."

[0099] Furthermore, the liquid ejection head 1 according to the first embodiment may be characterized in that an auxiliary electrode LA1 containing Au is formed above at least a portion of the piezoelectric driving region RK1.

[0100] Therefore, the liquid ejection head 1 according to the first embodiment can reduce the resistance of the common electrode QB1 provided on the piezoelectric driving region RK1, thereby reducing the possibility that the potential of the common electrode QB1 will deviate from the desired potential. This makes it possible for the liquid ejection head 1 according to the first embodiment to suppress a decrease in the ejection performance of the liquid ejection head 1 caused by the potential of the common electrode QB1 deviating from the desired potential.

[0101] In the first embodiment, the auxiliary electrode LA1 is an example of a "conductive layer."

[0102] Furthermore, the liquid ejection head 1 according to the first embodiment may be characterized in that an auxiliary layer Hy1 containing NiCr is formed on at least a portion of the piezoelectric outer edge region RG1.

[0103] Therefore, in the liquid ejection head 1 of the first embodiment, the piezoelectric body Qm and the sealing substrate 25 can be easily bonded with an adhesive, compared to an embodiment in which the auxiliary layer Hy1 is not provided on the piezoelectric body outer edge region RG1.

[0104] Furthermore, the liquid ejection head 1 according to the first embodiment may be characterized in that the width of the piezoelectric driving region RK1 in the X1 direction is longer than the width of the piezoelectric outer edge region RG1 in the X1 direction.

[0105] Therefore, in the liquid ejection head 1 of the first embodiment, compared to an embodiment in which the width of the piezoelectric driving region RK1 in the X1 direction is shorter than the width of the piezoelectric outer edge region RG1 in the X1 direction, it is possible to increase the amplitude of the piezoelectric driving region RK1 when the piezoelectric element PZ1 is driven, thereby ensuring good ejection performance of the liquid ejection head 1.

[0106] Furthermore, in the liquid ejection head 1 according to the first embodiment, the piezoelectric outer edge region RG1 may have a central portion RGm that overlaps with multiple pressure chambers CV when the piezoelectric outer edge region RG1 is viewed in the X1 direction, and end portions RGs that do not overlap with the multiple pressure chambers CV when the piezoelectric outer edge region RG1 is viewed in the X1 direction, and the width of the central portion RGm in the X1 direction may be greater than the width of the end portions RGs in the X1 direction.

[0107] Therefore, compared to an embodiment in which the width of the center portion RGm in the X1 direction is shorter than the width of the end portions RGs in the X1 direction, the liquid ejection head 1 according to the first embodiment can ensure the strength of the center portion RGm, which is the portion of the piezoelectric outer edge region RG1 through which vibrations from the piezoelectric drive region RK1 propagate when the piezoelectric element PZ is driven. Furthermore, compared to an embodiment in which the width of the end portions RGs in the X1 direction is longer than the width of the center 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 by reducing the area of the piezoelectric body Qm. In other words, the liquid ejection head 1 according to the first embodiment can both ensure the strength of the portion of the piezoelectric outer edge region RG1 through which vibrations from the piezoelectric drive region RK1 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 by reducing the area of the piezoelectric body Qm.

[0108] In the first embodiment, the central portion RGm is an example of a "first partial region," and the end portions RGs are an example of a "second partial region."

[0109] Also, in the liquid ejection head 1 according to the first embodiment, the plurality of pressure chambers CV include a plurality of pressure chambers CV1 arranged along the Y1 direction intersecting the X1 direction. The piezoelectric outer edge region RG1 has an extending portion RGx extending in the X1 direction and an extending portion RGy extending in the Y1 direction. The extending portion RGx has a first extending portion region overlapping the plurality of pressure chambers CV1 when viewed in the Y1 direction, and the extending portion RGy has a central portion RGm (an example of the "second extending portion region") overlapping the plurality of pressure chambers CV1 when viewed in the X1 direction. The width of the second extending portion region in the X1 direction may be longer than the width of the first extending portion region in the Y1 direction.

[0110] Therefore, compared with a mode in which the width of the second extending portion region in the X1 direction is shorter than the width of the first extending portion region in the Y1 direction, in the liquid ejection head 1 according to the first embodiment, among the piezoelectric outer edge regions RG1, it is possible to ensure the strength of the second extending portion region, which is a portion where vibration propagates from the piezoelectric driving region RK1 when the piezoelectric element PZ is driven. Further, compared with a mode in which the width of the first extending portion region in the Y1 direction is longer than the width of the second extending portion region in the X1 direction, in the liquid ejection head 1 according to the first embodiment, it is possible to reduce the possibility of foreign matter mixing between the piezoelectric body Qm and the sealing substrate 25 due to the reduction of 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 achieve both ensuring the strength of the portion where vibration propagates from the piezoelectric driving region RK1 when the piezoelectric element PZ is driven among the piezoelectric outer edge regions RG1 and reducing the possibility of foreign matter mixing between the piezoelectric body Qm and the sealing substrate 25 due to the reduction of the area of the piezoelectric body Qm.

[0111] In the first embodiment, the Y1 direction is an example of the "second direction", the extending portion RGx is an example of the "first extending region", and the extending portion RGy is an example of the "second extending region".

[0112] <<B. Second Embodiment>> Hereinafter, a liquid discharge device according to a second embodiment will be described while referring to FIGS. 12 and 13. In each of the embodiments exemplified below, for elements whose operations and functions are the same as those of the first embodiment, the reference numerals used in the description of the first embodiment are reused, and detailed descriptions thereof are appropriately omitted as needed.

[0113] <<B.1. Outline of Liquid Discharge Head According to Second Embodiment>> The liquid discharge device according to the second embodiment is different from the liquid discharge device 100 according to the first embodiment in that it includes a liquid discharge head 1B instead of the liquid discharge head 1.

[0114] FIG. 12 is a cross-sectional view of the liquid discharge head 1B when viewed in cross-section in the Y2 direction for the liquid discharge head 1B according to the second embodiment. FIG. 13 is a plan view of the actuator substrate AT-B provided on the liquid discharge head 1B when viewed in plan in the Z1 direction for the actuator substrate AT-B.

[0115] As shown in FIGS. 12 and 13, the liquid discharge head 1B is different from the liquid discharge head 1 according to the first embodiment in that it includes a piezoelectric structure 27B having a piezoelectric body QmB 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 the piezoelectric drive region RK1, the piezoelectric outer edge region RG1, and the piezoelectric central region RP1, it further includes a piezoelectric support region RS1.

[0116] Here, as shown in FIGS. 12 and 13, the piezoelectric support region RS1 is located between the piezoelectric drive region RK1 and the piezoelectric outer edge region RG1 in the X-axis direction, and is provided separated from the piezoelectric drive region RK1 and the piezoelectric outer edge region RG1.

[0117] Also, the piezoelectric support region RS1 is provided at a position where at least a part of the piezoelectric support region RS1 and at least a part of the wall WB1 overlap when the liquid discharge head 1B is viewed in plan in the Z1 direction. In the following description, the region including the end portion of the wall WB1 in the X-axis direction located in the X1 direction will be referred to as the end portion Wt1, and the region including the end portion located in the X2 direction will be referred to as the end portion Wt2. In the second embodiment, the piezoelectric support region RS1 is provided at a position where at least a portion of the piezoelectric support region RS1 overlaps with at least a portion of the end portion Wt2 when the liquid ejection head 1B is viewed in a plane in the Z1 direction. Furthermore, the piezoelectric outer edge region RG1 is provided at a position where at least a portion of the piezoelectric outer edge region RG1 overlaps with at least a portion of the end portion Wt1 when the liquid ejection head 1B is viewed in a plane in the Z1 direction. However, the present invention is not limited to this configuration. The piezoelectric support region RS1 may be provided at a position where the piezoelectric support region RS1 does not overlap with the end portion Wt2 when the liquid ejection head 1B is viewed in a plane in the Z1 direction. Furthermore, the piezoelectric outer edge region RG1 may be provided at a position where the piezoelectric outer edge region RG1 and the end region Wt1 do not overlap when the liquid ejection head 1B is viewed in a plan view in the Z1 direction.

[0118] In the second embodiment, as an example, it is assumed that the piezoelectric body support region RS1 is provided at a position where at least a portion of the piezoelectric body support region RS1 and at least a portion of the throttle portion SB1 overlap when the liquid ejection head 1B is viewed in a plane in the Z1 direction. However, the present invention is not limited to this aspect. The piezoelectric body support region RS1 may be provided at a position where the piezoelectric body support region RS1 and the throttle portion SB1 do not overlap when the liquid ejection head 1B is viewed in a plane in the Z1 direction.

[0119] In the second embodiment, as an example, it is assumed that the piezoelectric body QmB is provided so that the width of the piezoelectric body driving region RK1 in the X-axis direction is greater than the width of the piezoelectric body outer edge region RG1 in the X-axis direction, and the width of the piezoelectric body outer edge region RG1 in the X-axis direction is greater than the width of the piezoelectric body support region RS1 in the X-axis direction. However, the width of the piezoelectric body outer edge region RG1 in the X-axis direction may be less than or equal to the width of the piezoelectric body support region RS1 in the X-axis direction.

[0120] 13, the second embodiment is assumed to have an extending portion RSy1 that extends in the X-axis direction at a position in the Y1 direction as viewed from the plurality of pressure chambers CV1 of the liquid ejection head 1B, and an extending portion RSy2 that extends in the X-axis direction at a position in the Y2 direction as viewed from the plurality of pressure chambers CV1 of the liquid ejection head 1B. That is, the second embodiment is assumed to have a case in which the piezoelectric support region RS1 is provided so as to surround the plurality of pressure chambers CV1 of the liquid ejection head 1.

[0121] Liquid ejection head 1B also differs from liquid ejection head 1 according to the first embodiment in that it includes a piezoelectric element PZ-B1 instead of piezoelectric element PZ1. Piezoelectric element PZ-B1 also differs from piezoelectric element PZ1 according to the first embodiment in that it includes a piezoelectric body QmB instead of piezoelectric body Qm. Piezoelectric structure 27B also differs from piezoelectric structure 27 according to the first embodiment in that it includes an auxiliary electrode Hx21 laminated on piezoelectric body support region RS1 and an auxiliary electrode Hx31 laminated on auxiliary electrode HC1. Piezoelectric structure 27B also differs from piezoelectric structure 27 according to the first embodiment in that it includes an auxiliary electrode LBB1 instead of auxiliary electrode LB1. The auxiliary electrode LBB1 is laminated on the common electrode QB1, the piezoelectric element QmB, the auxiliary electrode Hx11, the auxiliary electrode Hx21 provided on the piezoelectric element support region RS1, the auxiliary electrode Hx31, the auxiliary electrode Hx41 provided on the piezoelectric element outer edge region RG1, and the auxiliary electrode HC1. Note that the auxiliary electrode LBB1 only needs to be laminated on at least a portion of the common electrode QB1 provided on the piezoelectric element drive region RK1 and at least a portion of the auxiliary electrode Hx21 provided on the piezoelectric element support region RS1. Like the auxiliary electrode LB1, the auxiliary electrode LBB1 is formed of a conductive material such as gold (Au).

[0122] Incidentally, it is assumed that the liquid ejection head 1B has a substantially plane-symmetric configuration with a plane having the X-axis direction as the normal direction as the symmetric plane. Specifically, corresponding to the nozzle row Ln2, the liquid ejection head 1B includes a piezoelectric body support region RS2, which is an element symmetric to the piezoelectric body support region RS1, a piezoelectric element PZ-B2, which is an element symmetric to the piezoelectric element PZ-B1, and an auxiliary electrode LBB2, which is an element symmetric to the auxiliary electrode LBB1. 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.

[0123] <<B.2. Conclusion of the Second Embodiment>> As described above, the liquid ejection head 1B according to the second embodiment includes a pressure chamber substrate 23 provided with a plurality of pressure chambers CV including a pressure chamber CV1 extending in the X1 direction, and a piezoelectric element PZ-B1 disposed at a position in the Z2 direction when viewed from the pressure chamber substrate 23 so as to correspond to the pressure chamber CV1, and including a piezoelectric body QmB, a common electrode QB, and an individual electrode QC. The liquid ejection head 1B further includes a sealing substrate 25 provided with a recess OB1 for accommodating the piezoelectric element PZ-B1 and disposed at a position in the Z2 direction when viewed from the piezoelectric element PZ-B1. The piezoelectric body QmB has a piezoelectric body drive region RK1 extending from a position overlapping the pressure chamber CV1 to a position overlapping a wall WA1 among two walls of the recess OB1 in the X1 direction when the liquid ejection head 1B is viewed in plan with respect to the Z1 direction, a piezoelectric body outer edge region RG1 overlapping a wall WB1 among two walls of the recess OB1 in the X1 direction, and a piezoelectric body support region RS1 overlapping a wall WB1 among two walls of the recess OB1 in the X1 direction. The piezoelectric body support region RS1 is located between the piezoelectric body drive region RK1 and the piezoelectric body outer edge region RG1 in the X1 direction and is provided separately from the piezoelectric body drive region RK1 and the piezoelectric body outer edge region RG1.

[0124] Thus, according to the liquid ejection head 1B of the second embodiment, the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are spaced apart, which reduces the possibility of foreign matter entering between the piezoelectric body QmB and the sealing substrate 25 compared to an embodiment in which the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are continuously provided, and further reduces the possibility that, even if foreign matter does enter between the piezoelectric body QmB and the sealing substrate 25, the relative positional relationship between the piezoelectric body QmB and the sealing substrate 25 will fluctuate due to the foreign matter. Therefore, according to the second embodiment, as with the first embodiment, it is possible to suppress fluctuations in ejection characteristics due to foreign matter entering between the piezoelectric body QmB and the sealing substrate 25 compared to an embodiment in which the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are continuously provided.

[0125] Furthermore, according to the liquid ejection head 1B of the second embodiment, the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are provided at a distance from each other, and therefore, compared to an embodiment in which the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are provided continuously, the degree to which vibrations generated in the piezoelectric body driving region RK1 when the piezoelectric element PZ-B1 is driven by the drive signal Com are transmitted to the piezoelectric body outer edge region RG1 can be reduced. Therefore, according to the second embodiment, as with the first embodiment, compared to an embodiment in which the piezoelectric body driving region RK1 and the piezoelectric body outer edge region RG1 are provided continuously, the possibility of displacement of the pressure chamber substrate 23 due to vibrations of the piezoelectric body outer edge region RG1 is reduced, and the possibility of fluctuations in the volume and shape of the pressure chamber CV1 due to displacement of the pressure chamber substrate 23 can be reduced.

[0126] Furthermore, according to the liquid ejection head 1B of the second embodiment, since the piezoelectric body QmB has a piezoelectric body support region RS1, pressure is more easily transmitted from the piezoelectric body QmB to the sealing substrate 25 in the process of bonding the actuator substrate AT-B including the piezoelectric body QmB to the sealing substrate 25, or in the process of bonding the actuator chip including the actuator substrate AT-B and the sealing substrate 25 to other components such as the communicating plate 22, compared to an embodiment that does not have a piezoelectric body support region RS1, thereby enabling reliable bonding to be achieved in each bonding process.

[0127] 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 portion," 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 recess OB1 is an example of the "first recess," the sealing substrate 25 is an example of the "sealing plate," the piezoelectric driving region RK1 is an example of the "first region," the piezoelectric outer edge region RG1 is an example of the "second region," the piezoelectric support region RS1 is an example of the "fifth region," the wall WA1 is an example of "one of the two walls that the first recess has," and the wall WB1 is an example of "the other of the two walls that the first recess has."

[0128] Furthermore, in the liquid ejection head 1B of the second embodiment, the piezoelectric support region RS1 may be characterized in that, when the liquid ejection head 1 is viewed in a plane, it overlaps with the end region Wt2 of the end of the wall WB1 that is close to the recess OB1.

[0129] Thus, in the liquid ejection head 1B of the second embodiment, the piezoelectric support region RS1 and the end region Wt2 of the wall WB1 overlap, so that pressure is more easily transmitted from the piezoelectric QmB to the sealing substrate 25 compared to a configuration in which the piezoelectric support region RS1 and the wall WB do not overlap, thereby achieving reliable adhesion in each bonding process.

[0130] Furthermore, the liquid ejection head 1B according to the second embodiment may be characterized in that an auxiliary electrode LA1 containing Au is formed on the upper part of at least a portion of the piezoelectric driving region RK1, and an auxiliary electrode LBB1 containing Au is formed on the upper part of at least a portion of the piezoelectric support region RS1.

[0131] Therefore, the liquid ejection head 1B according to the second embodiment has a low resistance common electrode QB1 provided on the piezoelectric driving region RK1, and is able to reduce the possibility that the potential of the common electrode QB1 will deviate from the desired potential. This makes it possible for the liquid ejection head 1B according to the second embodiment to suppress a decrease in the ejection performance of the liquid ejection head 1B caused by the potential of the common electrode QB1 deviating from the desired potential.

[0132] In the second embodiment, the auxiliary electrode LA1 is an example of a "first conductive layer," and the auxiliary electrode LBB1 is an example of a "second conductive layer."

[0133] Furthermore, the liquid ejection head 1B according to the second embodiment may be characterized in that an auxiliary layer Hy1 containing NiCr is formed on at least a portion of the piezoelectric outer edge region RG1.

[0134] Therefore, in the liquid ejection head 1B of the second embodiment, the piezoelectric body QmB and the sealing substrate 25 can be easily bonded with an adhesive, compared to an embodiment in which the auxiliary layer Hy1 is not provided on the piezoelectric body outer edge region RG1.

[0135] Furthermore, the liquid ejection head 1B according to the second embodiment may be characterized in that the width of the piezoelectric driving 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 support region RS1 in the X1 direction.

[0136] Therefore, the liquid ejection head 1B of the second embodiment enables stronger adhesion between the piezoelectric body QmB and the sealing substrate 25 compared to an embodiment in which the width of the piezoelectric body outer edge region RG1 in the X1 direction is shorter than the width of the piezoelectric body support region RS1 in the X1 direction.

[0137] Furthermore, in the liquid ejection head 1B according to the second embodiment, the multiple pressure chambers CV may include multiple pressure chambers CV1 arranged along the Y1 direction that intersects with the X1 direction, and the piezoelectric support region RS1 may extend so as to surround the multiple pressure chambers CV1.

[0138] Therefore, in the liquid ejection head 1B of the second embodiment, compared to an embodiment in which the piezoelectric support region RS1 is arranged only on one side as viewed from the multiple pressure chambers CV1, pressure is more easily transmitted from the piezoelectric body QmB to the sealing substrate 25 in the process of bonding the actuator substrate AT-B including the piezoelectric body QmB to the sealing substrate 25, or in the process of bonding the actuator chip including the actuator substrate AT-B and the sealing substrate 25 to other components such as the communicating plate 22, thereby achieving reliable bonding in each bonding process.

[0139] In the second embodiment, the Y1 direction is an example of the "second direction."

[0140] Furthermore, in the liquid ejection head 1B according to the second embodiment, the pressure chamber substrate 23 may be characterized in that it has a communicating flow path BD1 that connects the communicating flow path BC1, through which ink is supplied, to the pressure chamber CV1, and includes a throttling portion SB1 that defines the wall surface of the communicating flow path BD1, which has a cross-sectional area smaller than that of the communicating flow path BC1 and the pressure chamber CV1, and the piezoelectric support region RS1 overlaps with the throttling portion SB1 when the liquid ejection head 1B is viewed in a plane.

[0141] Therefore, in the liquid ejection head 1B of the second embodiment, compared to an embodiment in which the piezoelectric support region RS1 does not overlap with the constriction portion SB1, pressure is more easily transmitted from the piezoelectric body QmB to the sealing substrate 25 in the process of bonding the actuator substrate AT-B including the piezoelectric body QmB to the sealing substrate 25, or in the process of bonding the actuator chip including the actuator substrate AT-B and the sealing substrate 25 to other components such as the communicating plate 22, thereby achieving reliable bonding in each bonding process.

[0142] In the second embodiment, the ink is an example of a "liquid", the communication channel BC1 is an example of a "supply chamber", and the communication channel BD1 is an example of a "communication port".

[0143] <<B. Modified Example>> Each of the embodiments illustrated above can be variously modified. Specific modified forms are illustrated below. Two or more forms arbitrarily selected from the following illustrations can be appropriately combined within a range that does not conflict with each other.

[0144] <Modified Example 1> The liquid ejection device may include a liquid ejection head 1C instead of the liquid ejection head 1 or the liquid ejection head 1B described above.

[0145] FIG. 14 is a cross-sectional view of the liquid ejection head 1C according to this modified example when viewed in cross-section in the Y2 direction.

[0146] As shown in FIG. 14, the liquid ejection head 1C differs 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 differs 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, but does not include auxiliary electrodes Hx11, Hx31, Hx41, and HC1. The auxiliary electrodes HC11, HC12, and 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 support region RS1. The auxiliary electrode HC12 is provided on the insulating layer 242 in the piezoelectric body outer edge region RG1. The auxiliary layer HC13 is provided on the insulating layer 242 in the piezoelectric body outer edge region RG1 so as to be insulated from the auxiliary electrode HC12 at a position in the X1 direction as viewed 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 body outer edge region RG1.

[0147] In this modified example, the piezoelectric driving region RK1 and the piezoelectric outer edge region RG1 are also spaced apart, so that the degree to which the vibrations generated in the piezoelectric driving region RK1 when the piezoelectric element PZ-B1 is driven by the drive signal Com are transmitted to the piezoelectric outer edge region RG1 can be reduced compared to an embodiment in which the piezoelectric driving region RK1 and the piezoelectric outer edge region RG1 are continuously arranged.

[0148] <Variation 2> In the first and second embodiments and Modification 1 described above, a serial-type liquid ejection device in which the storage case 921 carrying the liquid ejection head 1, 1B, or 1C is moved back and forth in the X-axis direction is exemplified, but the present invention is not limited to such an embodiment. The liquid ejection device may also be a line-type liquid ejection device in which multiple nozzles N are distributed across the entire width of the medium PP.

[0149] <Variation 3> The liquid ejection devices exemplified in the first and second embodiments and modified examples 1 and 2 described above can be employed in various devices such as facsimile machines and copiers, as well as devices dedicated to printing. However, the use of the liquid ejection device of the present invention is not limited to printing. For example, a liquid ejection device that ejects a solution of a color material is used as a manufacturing device for forming color filters for liquid crystal display devices. Furthermore, a liquid ejection device that ejects a solution of a conductive material is used as a manufacturing device for forming wiring and electrodes for a wiring substrate. [Explanation of symbols]

[0150] 1...liquid ejection head, 1B...liquid ejection head, 21...nozzle substrate, 22...communicating plate, 23...pressure chamber substrate, 24...vibration plate, 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...outer edge region of piezoelectric body, RG2...outer edge region of piezoelectric body, RK1...piezoelectric body driving region, RK2...piezoelectric body driving region, RS1...piezoelectric body support region, WA1...wall, WB1...wall.

Claims

1. a pressure chamber substrate provided with a plurality of pressure chambers including a first pressure chamber extending in a first direction; a first piezoelectric element disposed on the pressure chamber substrate so as to correspond to the first pressure chamber, the first piezoelectric element including a piezoelectric body, an upper electrode, and a lower electrode; a sealing plate having a first recess for accommodating the first piezoelectric element and disposed above the first piezoelectric element; A liquid ejection head comprising: When the liquid ejection head is viewed from above in the vertical direction, the piezoelectric body has a first region extending from a position overlapping with the first pressure chamber to a position overlapping with one of two walls of the first recess in the first direction, a second region overlapping with the other of the two walls of the first recess in the first direction, and a fifth region overlapping with the other wall, the fifth region is located between the first region and the second region in the first direction and is spaced apart from the first region and the second region; A liquid ejection head characterized by:

2. the fifth region overlaps with an end region of the other wall that is close to the first recess when the liquid ejection head is viewed from above; 2. The liquid ejection head according to claim 1, wherein the liquid ejection head comprises: a first electrode;

3. a first conductive layer containing Au is formed on at least a portion of the first region; a second conductive layer containing Au is formed on at least a portion of the fifth region; 2. The liquid ejection head according to claim 1, wherein the liquid ejection head comprises: a first electrode;

4. an auxiliary layer containing NiCr is formed on at least a portion of the second region; 2. The liquid ejection head according to claim 1, wherein the liquid ejection head comprises: a first electrode;

5. a width of the first region in the first direction is greater than a width of the second region in the first direction; The width of the second region in the first direction is greater than the width of the fifth region in the first direction.

2. The liquid ejection head according to claim 1, wherein the liquid ejection head comprises: a first electrode;

6. the plurality of pressure chambers include a plurality of first pressure chambers arranged along a second direction intersecting the first direction, the fifth region extends so as to surround the plurality of first pressure chambers; 2. The liquid ejection head according to claim 1, wherein the liquid ejection head comprises: a first electrode;

7. the pressure chamber substrate includes a communication port that communicates the first pressure chamber with a supply chamber to which liquid is supplied, the communication port including a throttle portion that defines a wall surface of the communication port having a cross-sectional area smaller than those of the supply chamber and the first pressure chamber; the fifth region overlaps with the throttle portion when the liquid ejection head is viewed in a plan view; 2. The liquid ejection head according to claim 1, wherein the liquid ejection head comprises: a first electrode;

8. A liquid ejection head according to any one of claims 1 to 7, A liquid ejection device characterized by:

Images