Liquid dispensing head and liquid dispensing device

Abstract

To improve the discharge characteristics. [Solution] A pressure chamber substrate in which a plurality of pressure chambers are arranged in the direction of arrangement, a diaphragm, a first electrode, a first thin-film piezoelectric material, a second electrode, a second thin-film piezoelectric material, a third electrode, a third thin-film piezoelectric material, and a fourth electrode are stacked in this order from bottom to top along the direction of arrangement and the extension direction intersecting the direction of arrangement, with the set of the first electrode and the third electrode being designated as the first set, and the set of the second electrode and the fourth electrode being designated as the second set. One of the first and second sets is a set of multiple common electrodes that are provided in common to the plurality of pressure chambers and to which a reference voltage that does not change over time is applied, and the other of the first and second sets is a set of multiple individual electrodes that are provided individually to the plurality of pressure chambers so as to extend in the extension direction and to which a driving voltage that changes over time is applied.

Description

Technical Field

[0001] The present invention relates to a liquid ejection head and a liquid ejection device.

Background Art

[0002] Conventionally, a liquid ejection device including a liquid ejection head that ejects a liquid such as ink onto a medium such as printing paper has been proposed. As such a liquid ejection device, a piezoelectric inkjet printer is known. In the piezoelectric method, a piezoelectric element that vibrates a diaphragm constituting a part of the wall surface of a pressure chamber is used. By vibrating the diaphragm with the piezoelectric element, the liquid filled in the pressure chamber is ejected from the nozzle.

[0003] In the piezoelectric element included in the liquid ejection head described in Patent Document 1, a first common electrode, a lower piezoelectric layer of a thin film, an individual electrode, an upper piezoelectric layer of a thin film, and a second common electrode are laminated in this order. That is, the piezoelectric element has a configuration in which two thin film piezoelectric bodies are laminated.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the conventional liquid ejection head, the ejection characteristics may not be sufficient.

Means for Solving the Problems

[0006] A liquid discharge head according to a preferred embodiment of the present disclosure is a liquid discharge head comprising: a pressure chamber substrate having a plurality of pressure chambers arranged in a row in the direction of arrangement; a diaphragm; a first electrode; a first thin-film piezoelectric material; a second electrode; a second thin-film piezoelectric material; a third electrode; a third thin-film piezoelectric material; and a fourth electrode, all of which are stacked in this order from bottom to top along the row of arrangement direction and the extension direction intersecting the row of arrangement direction, wherein the set of the first electrode and the third electrode is designated as the first set, and the set of the second electrode and the fourth electrode is designated as the second set, wherein one of the first set and the second set is a set of a plurality of common electrodes that are commonly provided for the plurality of pressure chambers and to which a reference voltage that does not change over time is applied, and the other of the first set and the second set is a set of a plurality of individual electrodes that are individually provided for the plurality of pressure chambers so as to extend in the extension direction and to which a drive voltage that changes over time is applied.

[0007] A liquid dispensing device according to a preferred embodiment of the present disclosure comprises the above-described liquid dispensing head and a control unit that controls the dispensing operation from the liquid dispensing head. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic diagram showing the liquid dispensing device 100 according to the first embodiment. [Figure 2] Figure 1 shows an exploded perspective view of the liquid discharge head 1. [Figure 3] This is a cross-sectional view of a part of the liquid discharge head 1 shown in Figure 2, specifically the cross-sectional view taken along line III-III in Figure 2. [Figure 4] This is a cross-sectional view of a part of the liquid discharge head 1 shown in Figure 2, specifically the cross-sectional view along line IV-IV in Figure 2. [Figure 5] Figure 3 shows an enlarged cross-sectional view of the liquid discharge head 1 region AR. [Figure 6] A diagram showing the planar arrangement of the individual electrodes 7D and the common electrode 7C. [Figure 7] A diagram illustrating the drive voltage Com and the reference voltage VBS. [Figure 8] A diagram illustrating an example of the applied voltage Ea across four thin-film piezoelectric elements 7P. [Figure 9] A cross-sectional view of a portion of the liquid discharge head 1a in the second embodiment. [Figure 10] This is an enlarged cross-sectional view of region AR when liquid discharge head 1 shown in Figure 3 is replaced with liquid discharge head 1a. [Figure 11] A cross-sectional view of a portion of the liquid discharge head 1b in the third embodiment. [Figure 12] This is an enlarged cross-sectional view of region AR when liquid discharge head 1 shown in Figure 3 is replaced with liquid discharge head 1b. [Figure 13] This is an enlarged cross-sectional view of region AR when the liquid discharge head 1 shown in Figure 3 is replaced with the liquid discharge head 1c in the fourth embodiment. [Figure 14] A diagram showing the planar arrangement of the individual electrodes 7D and the common electrode 7C in the fourth embodiment. [Figure 15] This is an enlarged cross-sectional view of region AR when the liquid discharge head 1 shown in Figure 3 is replaced with the liquid discharge head 1d in the fifth embodiment. [Figure 16] A diagram showing the planar arrangement of the individual electrodes 7D and the common electrode 7C in the fifth embodiment. [Figure 17] A cross-sectional view of a portion of the liquid discharge head 1e in the sixth embodiment. [Modes for carrying out the invention]

[0009] Preferred embodiments of this disclosure will be described below with reference to the attached drawings. Note that the dimensions or scale of each part in the drawings may differ from the actual dimensions as appropriate, and some parts are shown schematically for ease of understanding. Furthermore, the scope of this disclosure is not limited to these forms unless otherwise stated in the following description. Note that "equal" includes not only cases where they are exactly equal, but also cases where there is a difference of the magnitude of measurement error. Also, "elements α and β are stacked" means that elements α and β are aligned vertically, and it is not necessary for elements α and β to be in direct contact.

[0010] The following description is made using the X-axis, Y-axis, and Z-axis that intersect each other as appropriate. One direction along the X-axis is referred to as the X1 direction, and the direction opposite to the X1 direction is referred to as the X2 direction. The directions opposite to each other along the Y-axis are referred to as the Y1 direction and the Y2 direction. The directions opposite to each other along the Z-axis are referred to as the Z1 direction and the Z2 direction. Looking in the direction along the Z-axis is referred to as "plan view". The Z-axis is typically a vertical axis. The Z1 direction is the upper side, and the Z2 direction is the lower side. However, the Z-axis does not have to be a vertical axis. Also, the X-axis, Y-axis, and Z-axis typically intersect at right angles to each other, but are not limited to this, and for example, they may intersect at an angle within the range of 80° or more and 100° or less.

[0011] 1. Embodiment 1-1. Overall Configuration of Liquid Discharge Device 100 FIG. 1 is a configuration diagram schematically showing a liquid discharge device 100 according to the first embodiment. The liquid discharge device 100 is an inkjet printing device that discharges ink, which is an example of a liquid, as droplets onto a medium M. The medium M is typically printing paper. Note that the medium M is not limited to printing paper, and for example, it may be a printing target of any material such as a resin film or fabric.

[0012] As shown in FIG. 1, a liquid container 90 for storing ink is attached to the liquid discharge device 100. Specific examples of the liquid container 90 include, for example, a cartridge that is detachable from the liquid discharge device 100, a bag-shaped ink pack formed of a flexible film, and an ink tank that can be refilled with ink. Note that the type of ink stored in the liquid container 90 is arbitrary.

[0013] The liquid dispensing device 100 includes a control unit 91, a transport mechanism 92, a moving mechanism 93, and a liquid dispensing head 1. The control unit 91 includes, for example, a processing circuit such as a CPU (Central Processing Unit) or FPGA (Field Programmable Gate Array) and a storage circuit such as a semiconductor memory, and controls the dispensing operation from the liquid dispensing head 1. The control unit 91 includes a voltage application circuit 910 that dispenses ink from the nozzle N by controlling the drive of a piezoelectric element 7, which will be described later. The voltage application circuit 910 applies a reference voltage VBS and a drive voltage Com, which will be described later, to the piezoelectric element 7. In this embodiment, unless otherwise specified, when defining a voltage difference, the difference between the voltage at the bottom of the piezoelectric element and the voltage at the top of the piezoelectric element is described as the "voltage difference". Note that the control unit 91 is an example of a "control unit".

[0014] The transport mechanism 92 transports the medium M in the Y2 direction under the control of the control unit 91. The moving mechanism 93 reciprocates the liquid discharge head 1 in the X1 and X2 directions under the control of the control unit 91. In the example shown in Figure 1, the moving mechanism 93 has a roughly box-shaped transport body 931 called a carriage that houses the liquid discharge head 1, and a transport belt 932 to which the transport body 931 is fixed. The number of liquid discharge heads 1 mounted on the transport body 931 is not limited to one, but may be multiple. In addition to the liquid discharge heads 1, a liquid container 90 may also be mounted on the transport body 931.

[0015] The liquid discharge head 1, under the control of the control unit 91, discharges ink supplied from the liquid container 90 onto the medium M from each of the multiple nozzles N in the Z2 direction. This discharge is performed in parallel with the transport of the medium M by the transport mechanism 92 and the reciprocating movement of the liquid discharge head 1 by the moving mechanism 93, thereby forming an image of ink on the surface of the medium M.

[0016] The liquid ejection device 100 includes a liquid ejection head 1 (described later) and a control unit 91. The control unit 91 includes a voltage application circuit 910 that ejects ink from the nozzle N.

[0017] 1-2. Overall configuration of the liquid dispensing head Figure 2 is an exploded perspective view of the liquid discharge head 1 shown in Figure 1. Figure 3 is a cross-sectional view of a part of the liquid discharge head 1 shown in Figure 2, specifically the cross-sectional view taken along line III-III in Figure 2. As shown in Figure 2, the liquid discharge head 1 has a plurality of nozzles N arranged in the direction along the Y axis. In the example shown in Figure 2, the plurality of nozzles N are divided into a first row L1 and a second row L2, which are spaced apart from each other in the direction along the X axis. Each of the first row L1 and the second row L2 is a set of a plurality of nozzles N arranged linearly in the direction along the Y axis. The elements associated with each nozzle N in the first row L1 and the elements associated with each nozzle N in the second row L2 of the liquid discharge head 1 are approximately symmetrical with respect to the direction along the X axis. In the following description, the elements corresponding to the first row L1 will be described in detail, and the description of the elements corresponding to the second row L2 will be omitted as appropriate.

[0018] The positions of the multiple nozzles N in the first row L1 and the multiple nozzles N in the second row L2 along the Y-axis may coincide or differ. Furthermore, elements related to each nozzle N in either the first row L1 or the second row L2 may be omitted.

[0019] As shown in Figures 2 and 3, the liquid discharge head 1 includes a nozzle plate 11, a vibration absorber 12, a flow path substrate 13, a pressure chamber substrate 14, a diaphragm 15, a wiring substrate 16, a housing 17, and a drive circuit 20. Each of the nozzle plate 11, vibration absorber 12, flow path substrate 13, pressure chamber substrate 14, diaphragm 15, wiring substrate 16, and housing 17 is a long, plate-shaped member in the direction along the Y axis. The nozzle plate 11, flow path substrate 13, pressure chamber substrate 14, diaphragm 15, and wiring substrate 16 are arranged in this order in the Z1 direction.

[0020] The nozzle plate 11 is a plate-shaped member on which a plurality of nozzles N are formed. Each of the plurality of nozzles N is a circular through-hole through which ink passes. The nozzles N eject ink by the vibration of the diaphragm 15. The nozzle plate 11 is joined to the flow path substrate 13, for example, by adhesive.

[0021] The flow channel substrate 13 has flow channels formed therein for supplying ink to multiple nozzles N. Specifically, the flow channel substrate 13 has a space Ra, multiple supply channels 131, multiple communication channels 132, and a supply liquid chamber 133. Space Ra is an elongated opening extending in the direction along the Y axis when viewed in a plan view along the Z axis. Each of the supply channels 131 and communication channels 132 is a through-hole formed for each nozzle N. The supply liquid chamber 133 is an elongated space extending in the direction along the Y axis across multiple nozzles N, and connects space Ra and the multiple supply channels 131 to each other. Each of the multiple communication channels 132 overlaps in a plan view with one nozzle N corresponding to that communication channel 132. The pressure chamber substrate 14 is joined to the flow channel substrate 13, for example, by adhesive.

[0022] Multiple pressure chambers C are provided in the pressure chamber substrate 14. The multiple pressure chambers C are arranged in a direction along the Y axis. Each pressure chamber C is formed for each nozzle N and is a long, elongated space that extends in a direction along the X axis in a plan view. The pressure chamber C is a space located between the flow path substrate 13 and the diaphragm 15. The pressure chamber C communicates with the nozzle N via the communication flow path 132 and also communicates with space Ra via the supply flow path 131 and the supply liquid chamber 133. The direction along the Y axis in which the multiple pressure chambers C are arranged is an example of an "arrangement direction".

[0023] The nozzle plate 11, the flow channel substrate 13, and the pressure chamber substrate 14 are each manufactured by processing a silicon single crystal substrate using, for example, dry etching or wet etching. However, other known methods may be used as appropriate for the manufacture of the nozzle plate 11, the flow channel substrate 13, and the pressure chamber substrate 14.

[0024] A diaphragm 15 is positioned on the surface of the pressure chamber substrate 14 facing the Z1 direction. The diaphragm 15 is a plate-shaped member that is elastically vibrable.

[0025] Multiple piezoelectric elements 7, corresponding to nozzles N, are arranged on the surface of the diaphragm 15 facing the Z1 direction. Each piezoelectric element 7 is elongated and extends along the X-axis in a plan view. The multiple piezoelectric elements 7 correspond to multiple pressure chambers C and are arranged along the Y-axis. The piezoelectric elements 7 deform when a voltage is applied. When the diaphragm 15 vibrates in conjunction with this deformation, the pressure in the pressure chambers C fluctuates, causing ink to be ejected from the nozzles N.

[0026] The housing 17 is a case for storing ink supplied to multiple pressure chambers C. As shown in Figure 3, a space Rb is formed in the housing 17. The space Rb in the housing 17 and the space Ra in the flow channel substrate 13 are in communication with each other. The space composed of space Ra and space Rb functions as a liquid storage chamber R, which is a reservoir for storing ink supplied to multiple pressure chambers C. Ink is supplied to the liquid storage chamber R through an inlet 171 formed in the housing 17. The ink in the liquid storage chamber R is supplied to the pressure chambers C via the supply liquid chamber 133 and each supply flow channel 131.

[0027] The vibration absorber 12 is a flexible film that forms the wall surface of the liquid storage chamber R. The vibration absorber 12 is a compliance substrate that absorbs pressure fluctuations of the ink in the liquid storage chamber R.

[0028] The wiring board 16 is a plate-shaped member on which wiring for electrically connecting the drive circuit 20 and the plurality of piezoelectric elements 7 is formed. The surface of the wiring board 16 facing the Z2 direction is joined to the diaphragm 15 via a plurality of conductive bumps 16B. On the other hand, the drive circuit 20 is mounted on the surface of the wiring board 16 facing the Z1 direction. The drive circuit 20 is an IC (Integrated Circuit) chip that outputs a drive voltage Com and a reference voltage VBS for driving each piezoelectric element 7.

[0029] As shown in Figure 2, the ends of the external wiring 21 are joined to the surface of the wiring board 16 facing the Z1 direction. The external wiring 21 is composed of connecting components such as FPC (Flexible Printed Circuits) or FFC (Flexible Flat Cable). The wiring board 16 has a plurality of wires 22 that electrically connect the external wiring 21 and the drive circuit 20, and a plurality of wires 23 to which the drive voltage Com and reference voltage VBS output from the drive circuit 20 are supplied.

[0030] Note that the wiring board 16 is not limited to a rigid board, but may also be an FPC (Flexible Printed Circuits) or FFC (Flexible Flat Cable), for example. In this case, the wiring board 16 may also serve as the external wiring 21.

[0031] 1-3.Vibration plate 15 Figure 4 is a cross-sectional view of a portion of the liquid discharge head 1 shown in Figure 2. The cross-sectional view shown in Figure 2 is the cross-section along line IV-IV in Figure 2. Figure 5 is an enlarged cross-sectional view of region AR of the liquid discharge head 1 shown in Figure 3. The diaphragm 15 shown in Figures 4 and 5 vibrates in response to the vibration of the piezoelectric element 7. The diaphragm 15 has, for example, a first layer 151 and a second layer 152. The first layer 151 and the second layer 152 are stacked in this order from bottom to top, i.e., in the Z1 direction.

[0032] The first layer 151 is an elastic film composed of, for example, silicon oxide (SiO2). This elastic film is formed, for example, by thermal oxidation of one side of a silicon single crystal substrate. The second layer 152 is an insulating film composed of, for example, zirconium oxide (ZrO2). This insulating film is formed, for example, by forming a zirconium layer by sputtering and then thermally oxidizing the layer. Zirconium oxide has excellent electrical insulation properties, mechanical strength, and toughness. Therefore, by including the second layer 152 containing zirconium oxide in the diaphragm 15, the characteristics of the diaphragm 15 can be improved.

[0033] Furthermore, other layers, such as metal oxides, may be interposed between the first layer 151 and the second layer 152. Also, part or all of the diaphragm 15 may be integrally formed with the pressure chamber substrate 14. In addition, the diaphragm 15 may be composed of layers of a single material.

[0034] 1-4. Piezoelectric element 7 As shown in Figure 3, the piezoelectric element 7 overlaps the aforementioned pressure chamber C in a plan view. As shown in Figures 4 and 5, the piezoelectric element 7 is arranged on the diaphragm 15. The piezoelectric element 7 includes a first common electrode 7C1, a first thin-film piezoelectric body 7P1, a first individual electrode 7D1, a second thin-film piezoelectric body 7P2, a second common electrode 7C2, a third thin-film piezoelectric body 7P3, a second individual electrode 7D2, a fourth thin-film piezoelectric body 7P4, and a third common electrode 7C3. The aforementioned pressure chamber substrate 14, diaphragm 15, first common electrode 7C1, first thin-film piezoelectric body 7P1, first individual electrode 7D1, second thin-film piezoelectric body 7P2, second common electrode 7C2, third thin-film piezoelectric body 7P3, second individual electrode 7D2, fourth thin-film piezoelectric body 7P4, and third common electrode 7C3 are stacked in this order from bottom to top. Furthermore, other layers, such as layers to improve adhesion, may be appropriately interposed between the layers of the piezoelectric element 7, or between the piezoelectric element 7 and the diaphragm 15. An example of a "stacking direction" is the direction along the Z-axis, which is the direction in which the elements of the piezoelectric element 7 are stacked.

[0035] In the first embodiment, the first common electrode 7C1 is an example of the "first electrode," the first individual electrode 7D1 is an example of the "second electrode," the second common electrode 7C2 is an example of the "third electrode," the second individual electrode 7D2 is an example of the "fourth electrode," and the third common electrode 7C3 is an example of the "fifth electrode." The combination of the first common electrode 7C1 and the second common electrode 7C2 is an example of the "first set," and the combination of the first individual electrode 7D1 and the second individual electrode 7D2 is an example of the "second set."

[0036] In the first embodiment, the two electrodes included in the pair of the first common electrode 7C1 and the second common electrode 7C2 are an example of "multiple common electrodes". Also, the first common electrode 7C1, the second common electrode 7C2, and the third common electrode 7C3 are also an example of "multiple common electrodes". Furthermore, the two electrodes included in the pair of the first individual electrode 7D1 and the second individual electrode 7D2 are an example of "multiple individual electrodes".

[0037] In the following, the first common electrode 7C1, the second common electrode 7C2, and the third common electrode 7C3 may be referred to collectively as the common electrode 7C. Similarly, the first thin-film piezoelectric element 7P1, the second thin-film piezoelectric element 7P2, the third thin-film piezoelectric element 7P3, and the fourth thin-film piezoelectric element 7P4 may be referred to collectively as the thin-film piezoelectric element 7P. Furthermore, the first individual electrode 7D1 and the second individual electrode 7D2 may be referred to collectively as the individual electrode 7D. As described above, the piezoelectric element 7 in the first embodiment has three common electrodes 7C, two individual electrodes 7D, and four thin-film piezoelectric elements 7P. No other thin-film piezoelectric elements 7P are formed above the third common electrode 7C3.

[0038] In a plan view along the Z-axis, the thin-film piezoelectric element 7P is separated from the multiple piezoelectric elements 7 by through-holes HO (described later) in the area that overlaps with the pressure chamber C, but it is connected in the area that does not overlap with the pressure chamber C and is a continuous component. However, the thin-film piezoelectric element 7P does not have to be a continuous component. Also, some of the four thin-film piezoelectric elements 7P may be a continuous component, while the remaining thin-film piezoelectric elements 7P may not be a continuous component.

[0039] 1-4a. Common electrode 7C The common electrode 7C is provided in common for the aforementioned multiple pressure chambers C. The common electrode 7C is a strip-shaped element that extends along the Y-axis so as to be continuous with the multiple pressure chambers C. A reference voltage VBS that does not change over time is applied to the common electrode 7C.

[0040] Examples of materials for the common electrode 7C include metallic materials or alloys such as platinum (Pt), iridium (Ir), aluminum (Al), nickel (Ni), gold (Au), and copper (Cu). The common electrode 7C may be a single layer or multiple layers. For example, the common electrode 7C has a laminated structure in which a layer made of platinum is stacked on top of a layer made of iridium.

[0041] 1-4b.Individual electrode 7D Individual electrodes 7D are provided individually for each of the multiple pressure chambers C. A time-varying drive voltage Com is applied to the individual electrodes 7D. In this embodiment, the same drive voltage Com is applied to each of the two individual electrodes 7D.

[0042] Examples of materials for the individual electrodes 7D include metal materials or alloys such as platinum, iridium, aluminum, nickel, gold, and copper. The individual electrodes 7D may be a single layer or multiple layers.

[0043] As can be seen from Figure 5, the length LD1 of the first individual electrode 7D1 along the X-axis is longer than the length LD2 of the second individual electrode 7D2 along the X-axis. In other words, of the two individual electrodes 7D, the length along the X-axis of the individual electrode 7D located relatively lower is longer than the length along the X-axis of the individual electrode 7D located upper. More specifically, the position of the end of the first individual electrode 7D1 in the X2 direction is approximately the same as the position of the end of the second individual electrode 7D2 in the X2 direction, and the position of the end of the first individual electrode 7D1 in the X1 direction is located in the X1 direction more than the position of the end of the second individual electrode 7D2 in the X2 direction. Note that the first individual electrode 7D1 is an example of "one individual electrode located relatively lower than the other of the two individual electrodes," and the second individual electrode 7D2 is an example of "the other individual electrode."

[0044] Furthermore, the length LC1 of the first common electrode 7C1 along the X-axis is longer than the length LC2 of the second common electrode 7C2 along the X-axis. Length LC2 is longer than the length LC3 of the third common electrode 7C3 along the X-axis. In other words, the further down the three common electrodes 7C are located, the longer their length along the X-axis. More specifically, the position of the end of the first common electrode 7C1 in the X2 direction, the position of the end of the second common electrode 7C2 in the X2 direction, and the position of the end of the third common electrode 7C3 in the X2 direction are approximately the same. The position of the end of the first common electrode 7C1 in the X2 direction is located further in the X1 direction than the position of the end of the second common electrode 7C2 in the X2 direction. The position of the end of the second common electrode 7C2 in the X2 direction is located further in the X1 direction than the position of the end of the third common electrode 7C3 in the X2 direction.

[0045] 1-4c. Thin-film piezoelectric material 7P The thin-film piezoelectric material 7P is composed of a composite oxide. Specifically, the thin-film piezoelectric material 7P is composed of a piezoelectric material having a perovskite crystal structure. Examples of such piezoelectric materials include lead titanate (PbTiO3), lead zirconate titanate (PZT:Pb(Zr,Ti)O3), lead zirconate (PbZrO3), lead lanthanum titanate ((Pb,La),TiO3), lead lanthanum zirconate titanate ((Pb,La)(Zr,Ti)O3), lead zirconium niobate titanate (Pb(Zr,Ti,Nb)O3), and lead zirconium magnesium niobate titanate (Pb(Zr,Ti)(Mg,Nb)O3). Among these, lead zirconate titanate (PZT) is preferably used as the constituent material of the thin-film piezoelectric material. The thin-film piezoelectric material may contain small amounts of other elements such as impurities. Each of the four thin-film piezoelectric elements 7P may be a single layer or multiple layers.

[0046] Each of the four thin-film piezoelectric elements 7P may be made of the same material, but it is preferable that some of them be made of different materials. Depending on the type of piezoelectric element 7 to be formed, the desired physical properties of each of the four thin-film piezoelectric elements 7P may differ. For this reason, if each of the four thin-film piezoelectric elements 7P is made of the same material, the degree of design freedom is reduced, and it becomes difficult to achieve optimal physical properties for each of the four thin-film piezoelectric elements 7P. By making each of the four thin-film piezoelectric elements 7P from different materials, it is possible to design optimal physical properties for each of the four thin-film piezoelectric elements 7P. Therefore, it is possible to find the desired piezoelectric element 7. Even if each of the four thin-film piezoelectric elements 7P is made of the same multiple materials, the distribution ratio of the multiple materials may be the same or different.

[0047] From another perspective, it is preferable that each of the four thin-film piezoelectric elements 7P is made of the same material. Having each of the four thin-film piezoelectric elements 7P be made of the same material simplifies manufacturing and makes it easier to design desired physical properties, for example, simply by controlling the film thickness.

[0048] Furthermore, each of the four thin-film piezoelectric elements 7P is a thin film. Specifically, the thickness of each of the four thin-film piezoelectric elements 7P is preferably 5 μm or less, and more preferably 2 μm or less. Note that the thicknesses of each of the four thin-film piezoelectric elements 7P may be the same or different.

[0049] As can be seen from Figures 4 and 5, each of the four thin-film piezoelectric elements 7P is formed to cover a portion of at least one of the three common electrodes 7C and the two individual electrodes 7D. Specifically, as shown in Figure 5, the first thin-film piezoelectric element 7P1 is formed to cover the first common electrode 7C1 at its end in the X1 direction. As shown in Figure 4, the second thin-film piezoelectric element 7P2 is formed to cover the first individual electrode 7D1 at its ends in the Y1 and Y2 directions, and at its end in the X1 direction, it is formed to cover the first individual electrode 7D1, the first thin-film piezoelectric element 7P1, and the first common electrode 7C1. As shown in Figure 5, the third thin-film piezoelectric element 7P3 is formed to cover the second common electrode 7C2 at its end in the X1 direction. As shown in Figure 4, the fourth thin-film piezoelectric element 7P4 is formed to cover the second individual electrode 7D2 at its ends in the Y1 and Y2 directions, and as shown in Figure 5, it is formed to cover the second individual electrode 7D2, the third thin-film piezoelectric element 7P3, and the second common electrode 7C2 at its end in the X1 direction. Therefore, the thickness of each of the four thin-film piezoelectric elements 7P differs between the parts that overlap with the electrodes and other components in a plan view and the parts that do not. Accordingly, as shown in Figure 4, the thinnest thickness TP1 of the first thin-film piezoelectric element 7P1, the thinnest thickness TP2 of the second thin-film piezoelectric element 7P2, the thinnest thickness TP3 of the third thin-film piezoelectric element 7P3, and the thinnest thickness TP4 of the fourth thin-film piezoelectric element 7P4 are preferably 5 μm or less, and more preferably 2 μm or less.

[0050] Figure 6 shows the planar arrangement of the individual electrodes 7D and the common electrode 7C. As shown in Figure 6, each individual electrode 7D is elongated and extends along the X-axis. Multiple individual electrodes 7D are spaced apart from each other and arranged along the Y-axis. As shown in Figure 5, one end of each individual electrode 7D in the longitudinal direction along the X-axis is connected to an individual wiring section 73 for applying the drive voltage Com. The direction along the X-axis in which each individual electrode 7D extends is an example of the "extension direction".

[0051] The individual wiring section 73 is provided such that it short-circuits the first individual electrode 7D1 and the second individual electrode 7D2. Specifically, the individual wiring section 73 has a first wiring section 731, a second wiring section 732, a third wiring section 733, a fourth wiring section 734, and a fifth wiring section 735. The first wiring section 731 extends in the direction along the X-axis and is provided above the third thin-film piezoelectric body 7P3, specifically above the fourth thin-film piezoelectric body 7P4. The second wiring section 732 branches off from the first wiring section 731 and extends in the direction along the Z-axis, penetrating the second thin-film piezoelectric body 7P2 and the fourth thin-film piezoelectric body 7P4, and connects to the first individual electrode 7D1. Specifically, the second wiring section 732 penetrates the contact hole H1 that penetrates the second thin-film piezoelectric body 7P2 and the fourth thin-film piezoelectric body 7P4. The third wiring section 733 branches off from the first wiring section 731, extends along the Z-axis so as to penetrate the fourth thin-film piezoelectric element 7P4, and connects to the second individual electrode 7D2. Specifically, the third wiring section 733 is provided so as to penetrate the contact hole H2 that penetrates the fourth thin-film piezoelectric element 7P4. As can be seen from Figure 5, when viewed along the Y-axis, the second wiring section 732 is located between the fourth wiring section 734 and the third wiring section 733. The fourth wiring section 734 extends along the Z-axis along the X1-direction side of the second thin-film piezoelectric element 7P2 and the fourth thin-film piezoelectric element 7P4, connects to the first wiring section 731 at its Z1-direction end, and connects to the fifth wiring section 735 at its Z2-direction end. The fifth wiring section 735 is provided on the Z1-direction-facing surface of the diaphragm 15 and connects to the wiring 70 that extends along the Y-axis. The wiring 70 is electrically connected to the drive circuit 20 mounted on the wiring board 16 via the aforementioned conductive bumps 16B. Thus, the two individual electrodes 7D are electrically connected to the drive circuit 20 via the individual wiring section 73 and the wiring 70.

[0052] As can be seen from Figure 5, the length T32 of the second wiring section 732 in the direction along the Z axis is longer than the length T33 of the third wiring section 733 in the direction along the Z axis. The length T33 is equal to the thinnest thickness TP4 of the fourth thin-film piezoelectric material 7P4. The length T32 is the sum of the thickness TP4, the thickness of the second individual electrode 7D2, the thickness TP3, the thickness of the second common electrode 7C2, and the thickness TP2. As shown in Figure 14, in a plan view, the cross-sectional area S32 of the second wiring section 732 is approximately the same as the cross-sectional area S33 of the third wiring section 733, but may be different.

[0053] As shown in Figure 6, the common electrode 7C is connected to a common wiring section 74 for applying a reference voltage VBS to the common electrode 7C. The common wiring section 74 is provided so as to short-circuit the three common electrodes 7C. The common wiring section 74 has a sixth wiring section 746, a seventh wiring section 747, and an eighth wiring section 748. The sixth wiring section 746 is shaped like a flat plate bent in two places, and in plan view it is U-shaped with each vertex being approximately right angle. More specifically, the sixth wiring section 746 is formed to cover a part of the side surface in the Y1 direction, a part of the side surface in the Y2 direction, and all of the side surface in the X2 direction of the second thin-film piezoelectric body 7P2 and the fourth thin-film piezoelectric body 7P4. The sixth wiring section 746 is connected to the third common electrode 7C3 at its end in the Z1 direction and to the first common electrode 7C1 and the seventh wiring section 747 at its end in the Z2 direction. Furthermore, the sixth wiring section 746 is connected to the second common electrode 7C2 at a position on the Z1-direction surface of the second thin-film piezoelectric element 7P2 in the Z-axis direction. The seventh wiring section 747 is a flat plate shape with a notch on its edge in the X1 direction on the Z1-direction surface of the diaphragm 15. More specifically, in a plan view, the seventh wiring section 747 is provided on a part of the Y1-direction side surface, a part of the Y2-direction side surface, and near the X2-direction side surface of the second thin-film piezoelectric element 7P2 and the fourth thin-film piezoelectric element 7P4, without overlapping with the fourth thin-film piezoelectric element 7P4. The eighth wiring section 748 is provided on the Z1-direction surface of the diaphragm 15, extending in a direction along the X-axis. The X2-direction end of the eighth wiring section 748 is connected to the seventh wiring section 747. The eighth wiring section 748 is electrically connected to the drive circuit 20 mounted on the wiring board 16 via the aforementioned conductive bumps 16B. As a result, the three common electrodes 7C are electrically connected to the drive circuit 20 via the common wiring section 74.

[0054] Furthermore, as can be seen from Figure 5, the individual wiring section 73 is located in the X1 direction relative to the two individual electrodes 7D, and the common wiring section 74 is located in the X2 direction relative to the three common electrodes 7C. In plan view, the second wiring section 732 does not overlap with the first common electrode 7C1. Compared to the configuration in which the second wiring section 732 overlaps with the first common electrode 7C1 in plan view, this embodiment can suppress deformation of the first thin-film piezoelectric body 7P1 at position P1. Position P1 is within the first thin-film piezoelectric body 7P1 and is the same position as the second wiring section 732 in the direction along the X axis. By suppressing deformation of the first thin-film piezoelectric body 7P1 at position P1, it is possible to prevent the second wiring section 732 from peeling off from the first individual electrode 7D1. To suppress the delamination of the second wiring portion 732 from the first individual electrode 7D1, one could consider increasing the cross-sectional area of ​​the second wiring portion 732 and increasing the contact area with the first individual electrode 7D1. However, increasing the cross-sectional area of ​​the second wiring portion 732 is equivalent to increasing the diameter of the contact hole H1, and increasing the diameter of the contact hole H1 reduces the strength of the second thin-film piezoelectric body 7P2. Therefore, according to the first embodiment, it is possible to suppress the delamination of the second wiring portion 732 from the first individual electrode 7D1 while maintaining the strength of the second thin-film piezoelectric body 7P2. Similarly, in a plan view, the third wiring portion 733 does not overlap with the second common electrode 7C2. Compared to an embodiment in which the third wiring portion 733 overlaps with the second common electrode 7C2 in a plan view, this embodiment can suppress deformation of the second thin-film piezoelectric body 7P2 at position P2. Position P2 is within the second thin-film piezoelectric body 7P2 and is the same position as the third wiring portion 733 in the direction along the X axis.

[0055] 1-5. Operation of the piezoelectric element 7 Figure 7 is a diagram illustrating the driving voltage Com and the reference voltage VBS. In Figure 7, the horizontal axis represents time, and the vertical axis represents voltage [V]. A voltage is applied to the piezoelectric element 7 by the voltage application circuit 910 described above. Specifically, the voltage application circuit 910 applies a voltage to the four thin-film piezoelectric elements 7P via three common electrodes 7C and two individual electrodes 7D. The first thin-film piezoelectric element 7P1 deforms according to the voltage applied between the first common electrode 7C1 and the first individual electrode 7D1. The second thin-film piezoelectric element 7P2 deforms according to the voltage applied between the first individual electrode 7D1 and the second common electrode 7C2. The third thin-film piezoelectric element 7P3 deforms according to the voltage applied between the second common electrode 7C2 and the second individual electrode 7D2. The fourth thin-film piezoelectric element 7P4 deforms according to the voltage applied between the second individual electrode 7D2 and the third common electrode 7C3.

[0056] A drive voltage Com is applied to each of the two individual electrodes 7D, corresponding to the ink ejection amount. The drive voltage Com changes over time. The drive voltage Com includes a drive waveform WCom. The drive waveform WCom repeats for a unit period Tu. The drive waveform WCom includes an intermediate voltage Ek, a maximum voltage En, and a minimum voltage Em. The maximum voltage En is the maximum value of the drive voltage Com. The minimum voltage Em is the minimum value of the drive voltage Com. The drive waveform WCom decreases from the intermediate voltage Ek to the minimum voltage Em, maintains the minimum voltage Em, then increases from the minimum voltage Em to the maximum voltage En, maintains the maximum voltage En, and then decreases to the intermediate voltage Ek. Note that the drive waveform WCom shown in Figure 7 is just an example, and the drive voltage Com may have other waveforms.

[0057] A constant reference voltage VBS is applied to each of the three common electrodes 7C, regardless of the ink ejection rate. The reference voltage VBS remains constant over time. In the illustrated example, the reference voltage VBS is higher than the minimum voltage Em of the drive voltage Com, but is not limited to this. The reference voltage VBS may also be at GND potential, i.e., 0[V].

[0058] Figure 8 shows an example of the applied voltage Ea across the four thin-film piezoelectric elements 7P. The applied voltage Ea shown in Figure 8 is the value obtained by subtracting the reference voltage VBS from the drive voltage Com shown in Figure 7 at each time point.

[0059] When the driving voltage Com and the reference voltage VBS are applied, the difference between the driving voltage Com and the reference voltage VBS is applied to the first thin-film piezoelectric element 7P1 between the first common electrode 7C1 and the first individual electrode 7D1, causing the first thin-film piezoelectric element 7P1 to deform. Similarly, when the driving voltage Com and the reference voltage VBS are applied, the difference between the driving voltage Com and the reference voltage VBS is applied to the second thin-film piezoelectric element 7P2 between the second common electrode 7C2 and the first individual electrode 7D1, causing the second thin-film piezoelectric element 7P2 to deform. Furthermore, when the driving voltage Com and the reference voltage VBS are applied, the difference between the driving voltage Com and the reference voltage VBS is applied to the third thin-film piezoelectric element 7P3 between the second common electrode 7C2 and the second individual electrode 7D2, causing the third thin-film piezoelectric element 7P3 to deform. Furthermore, when the driving voltage Com and the reference voltage VBS are applied, the difference between the driving voltage Com and the reference voltage VBS is applied to the fourth thin-film piezoelectric element 7P4 between the third common electrode 7C3 and the second individual electrode 7D2, causing the fourth thin-film piezoelectric element 7P4 to deform.

[0060] When the maximum voltage EN shown in Figure 8 is applied to the four thin-film piezoelectric elements 7P, the first thin-film piezoelectric element 7P1 and the third thin-film piezoelectric element 7P3 are affected by an electric field directed in the Z2 direction. The second thin-film piezoelectric element 7P2 and the fourth thin-film piezoelectric element 7P4 are affected by an electric field directed in the Z1 direction. Thus, although the direction of the electric field affecting the four thin-film piezoelectric elements 7P is different, the magnitude of the electric field is the same.

[0061] The piezoelectric element 7, which includes the four thin-film piezoelectric elements 7P described above, deforms in the Z1 direction during the expansion period T2, when the voltage is reduced from the intermediate voltage EK to the minimum voltage EM as shown in Figure 8, causing the pressure chamber C to expand. In other words, the piezoelectric element 7 deforms upward to expand the pressure chamber C. As a result, ink is drawn into the pressure chamber C. Next, during the contraction period T1, when the voltage is increased from the minimum voltage EM to the maximum voltage EN, causing the pressure chamber C to contract, the piezoelectric element 7 and the diaphragm 15 deform in the Z2 direction. In other words, the piezoelectric element 7 deforms downward to contract the pressure chamber C. As a result, the ink in the pressure chamber C is ejected from the nozzle N.

[0062] 1-6. Summary of the First Embodiment The following is a summary of the liquid discharge head 1 in the first embodiment. The liquid discharge head 1 consists of a pressure chamber substrate 14 on which a plurality of pressure chambers C are arranged in line along the Y axis, a diaphragm 15, a first common electrode 7C1, a first thin-film piezoelectric body 7P1, a first individual electrode 7D1, a second thin-film piezoelectric body 7P2, a second common electrode 7C2, a third thin-film piezoelectric body 7P3, and a second individual electrode 7D2, which are stacked in this order from bottom to top along the Z axis. The first set consists of the first common electrode 7C1 and the second common electrode 7C2, and the second set consists of the first individual electrode 7D1 and the second individual electrode 7D2. The first set consists of a plurality of common electrodes 7C that are commonly provided for the plurality of pressure chambers C and to which a reference voltage VBS that does not change over time is applied, and the second set consists of a plurality of individual electrodes 7D that are individually provided for the plurality of pressure chambers C, extending in the direction along the X axis, and to which a driving voltage Com that changes over time is applied. According to the first embodiment, since four thin-film piezoelectric elements 7P are stacked, the displacement per unit voltage can be increased compared to the embodiment in which two thin-film piezoelectric elements 7P are stacked. Therefore, when the same voltage applied to the piezoelectric element 7 in the first embodiment as the voltage applied to the two thin-film piezoelectric elements in the embodiment in which two thin-film piezoelectric elements are stacked is applied, the discharge characteristics can be improved. Alternatively, by lowering the voltage applied to the piezoelectric element 7 in the first embodiment, costs can be reduced by replacing it with a component with a lower rated voltage while maintaining the discharge characteristics. Discharge characteristics include, for example, the discharge volume and / or discharge speed.

[0063] Furthermore, the liquid discharge head 1 includes a common wiring section 74 for applying a reference voltage VBS to a plurality of common electrodes 7C included in the first set, and individual wiring sections 73 for applying a drive voltage Com to a plurality of individual electrodes 7D included in the second set.

[0064] Furthermore, the individual wiring section 73 is provided such that multiple individual electrodes 7D included in the second set are short-circuited to each other. By short-circuiting multiple individual electrodes 7D, the individual wiring section 73 can be used as a common wiring for multiple individual electrodes 7D. Therefore, according to the first embodiment, the area occupied by the wiring can be reduced compared to a configuration in which each of the multiple individual electrodes 7D has its own separate wiring. By reducing the area occupied by the wiring, the liquid discharge head 1 can be made smaller.

[0065] Furthermore, the individual wiring section 73 includes a first wiring section 731 provided above the third thin-film piezoelectric element 7P3, a second wiring section 732 branching from the first wiring section 731 and extending in a direction along the Z-axis so as to penetrate the second thin-film piezoelectric element 7P2 and connecting to the first individual electrode 7D1, and a third wiring section 733 branching from the first wiring section 731 and extending in a direction along the Z-axis and connecting to the second individual electrode 7D2. According to the first embodiment, the first wiring section 731 is used as a common wiring for the first individual electrode 7D1 and the second individual electrode 7D2, while the second wiring section 732 can supply a drive voltage Com to the first individual electrode 7D1 and the third wiring section 733 can supply a drive voltage Com to the second individual electrode 7D2.

[0066] Furthermore, the common wiring section 74 is provided such that it short-circuits the multiple common electrodes 7C included in the first set. According to the first embodiment, by short-circuiting multiple common electrodes 7C, the common wiring section 74 can be used as a common wiring for multiple common electrodes 7C. Therefore, according to the first embodiment, the area occupied by the wiring can be reduced compared to a configuration in which separate wiring exists for each of the multiple common electrodes 7C.

[0067] Furthermore, the fourth thin-film piezoelectric material 7P4 and the third common electrode 7C3 are further stacked on the upper side of the second individual electrode 7D2 in this order, and no other thin-film piezoelectric material 7P is formed on the upper side of the third common electrode 7C3. According to the first embodiment, compared to an embodiment in which two thin-film piezoelectric elements 7P are stacked, four thin-film piezoelectric elements 7P are stacked, which allows for a larger displacement per unit voltage.

[0068] Furthermore, the first common electrode 7C1, the second common electrode 7C2, and the third common electrode 7C3 are multiple common electrodes 7C, and the first individual electrode 7D1 and the second individual electrode 7D2 are multiple individual electrodes 7D. According to the first embodiment, a driving voltage Com and a reference voltage VBS can be applied to four thin-film piezoelectric elements 7P using five electrodes.

[0069] Furthermore, the multiple individual electrodes 7D consist of two individual electrodes 7D, and the length LD1 along the X-axis of the first individual electrode 7D1, which is the individual electrode 7D located relatively lower than the other individual electrode 7D, is longer than the length LD2 along the X-axis of the second individual electrode 7D2, which is the other individual electrode 7D. In the configuration where length LD2 is longer than length LD1, the second wiring section 732 and the second individual electrode 7D2 overlap, requiring a through hole to be provided in the second individual electrode 7D2, which increases the manufacturing process of the piezoelectric element 7. Furthermore, in the configuration where length LD2 is longer than length LD1, the first individual electrode 7D1 is shortened, which reduces the active region of the piezoelectric element 7 and deteriorates the discharge characteristics. Therefore, according to the first embodiment, compared to the configuration where length LD2 is longer than length LD1, the discharge characteristics of the liquid discharge head 1 can be maintained while suppressing the increase in the manufacturing process of the piezoelectric element 7.

[0070] Furthermore, the liquid dispensing device 100 includes a liquid dispensing head 1 and a control unit 91 that controls the dispensing operation from the liquid dispensing head 1. According to the first embodiment, a liquid dispensing device 100 can be provided that can increase the amount of displacement per unit voltage compared to a configuration in which two thin-film piezoelectric elements 7P are stacked.

[0071] 2. Second Embodiment The first embodiment had four thin-film piezoelectric elements 7P, but is not limited to this. The second embodiment will be described below.

[0072] 2-1. Piezoelectric element 7a in the second embodiment Figure 9 is a cross-sectional view of a part of the liquid discharge head 1a in the second embodiment. The cross-sectional view shown in Figure 9 is the cross-section along line IV-IV in Figure 2 when the liquid discharge head 1 shown in Figure 2 is replaced with the liquid discharge head 1a. Figure 10 is an enlarged cross-sectional view of region AR when the liquid discharge head 1 shown in Figure 3 is replaced with the liquid discharge head 1a. The liquid discharge head 1a differs from the liquid discharge head 1 in that it has a piezoelectric element 7a instead of the piezoelectric element 7.

[0073] The piezoelectric element 7a comprises a first individual electrode 7D1a, a first thin-film piezoelectric body 7P1a, a first common electrode 7C1a, a second thin-film piezoelectric body 7P2a, a second individual electrode 7D2a, a third thin-film piezoelectric body 7P3a, and a second common electrode 7C2a. The first individual electrode 7D1a, the first thin-film piezoelectric body 7P1a, the first common electrode 7C1a, the second thin-film piezoelectric body 7P2a, the second individual electrode 7D2a, the third thin-film piezoelectric body 7P3a, and the second common electrode 7C2a are stacked in this order from bottom to top.

[0074] In the following, the first individual electrode 7D1a and the second individual electrode 7D2a may be referred to collectively as individual electrode 7Da without distinction. Also, the first thin-film piezoelectric body 7P1a, the second thin-film piezoelectric body 7P2a, and the third thin-film piezoelectric body 7P3a may be referred to collectively as thin-film piezoelectric body 7Pa without distinction. Furthermore, the first common electrode 7C1a and the second common electrode 7C2a may be referred to collectively as common electrode 7Ca without distinction. As described above, the piezoelectric element 7a in the second embodiment has two common electrodes 7Ca, two individual electrodes 7Da, and three thin-film piezoelectric bodies 7Pa. No other thin-film piezoelectric body is formed above the second common electrode 7C2a.

[0075] In the second embodiment, the first individual electrode 7D1a is an example of the "first electrode," the first common electrode 7C1a is an example of the "second electrode," the second individual electrode 7D2a is an example of the "third electrode," and the second common electrode 7C2a is an example of the "fourth electrode." Furthermore, the combination of the first individual electrode 7D1a and the second individual electrode 7D2a is an example of the "first set," and the combination of the first common electrode 7C1a and the second common electrode 7C2a is an example of the "second set."

[0076] In the first embodiment, the two electrodes included in the pair of the first individual electrode 7D1a and the second individual electrode 7D2a are an example of "multiple individual electrodes". Also, the two electrodes included in the pair of the first common electrode 7C1a and the second common electrode 7C2a are an example of "multiple common electrodes".

[0077] As can be seen from Figure 10, the length LD1a of the first individual electrode 7D1a along the X-axis is longer than the length LD2a of the second individual electrode 7D2a along the X-axis. In other words, of the two individual electrodes 7Da, the length along the X-axis of the individual electrode 7Da located relatively lower is longer than the length along the X-axis of the individual electrode 7Da located upper. More specifically, the position of the end of the first individual electrode 7D1a in the X2 direction is approximately the same as the position of the end of the second individual electrode 7D2a in the X2 direction, and the position of the end of the first individual electrode 7D1a in the X1 direction is located in the X1 direction more than the position of the end of the second individual electrode 7D2a in the X2 direction. In the second embodiment, the first individual electrode 7D1a is an example of "one of the two individual electrodes located relatively lower," and the second individual electrode 7D2a is an example of "the other individual electrode."

[0078] Furthermore, the length LC1a of the first common electrode 7C1a along the X-axis is longer than the length LC2a of the second common electrode 7C2a along the X-axis. The lower the two common electrodes 7Ca are located, the longer their length along the X-axis. More specifically, the position of the end of the first common electrode 7C1a in the X2 direction is approximately the same as the position of the end of the second common electrode 7C2a in the X2 direction. The position of the end of the first common electrode 7C1a in the X2 direction is located in the X1 direction more than the position of the end of the second common electrode 7C2a in the X2 direction.

[0079] Similar to the first embodiment, each of the three thin-film piezoelectric elements 7Pa is a thin film. Specifically, the thickness of each of the three thin-film piezoelectric elements 7Pa is preferably 5 μm or less, and more preferably 2 μm or less.

[0080] As can be seen from Figures 9 and 10, each of the three thin-film piezoelectric elements 7Pa is formed to cover a portion of at least one of the two common electrodes 7Ca and the two individual electrodes 7Da. Specifically, the first thin-film piezoelectric element 7P1a is formed to cover the first individual electrode 7D1a at its ends in the Y1, Y2, X1, and X2 directions, as shown in Figures 9 and 10. The second thin-film piezoelectric element 7P2a is formed to cover the first individual electrode 7D1a at its end in the X1 direction, as shown in Figure 10. The third thin-film piezoelectric element 7P3a is formed to cover the second individual electrode 7D2a at its ends in the Y1 and Y2 directions, as shown in Figure 9, and to cover the second individual electrode 7D2a, the second thin-film piezoelectric element 7P2a, and the first common electrode 7C1a at its ends in the X1 and X2 directions, as shown in Figure 10. Therefore, the thickness of each of the three thin-film piezoelectric elements 7P differs in the portion that overlaps with the electrodes, etc., and the portion that does not overlap with them in a plan view. Accordingly, as shown in Figure 9, the thinnest thickness TP1a of the first thin-film piezoelectric element 7P1a, the thinnest thickness TP2a of the second thin-film piezoelectric element 7P2a, and the thinnest thickness TP3a ​​of the third thin-film piezoelectric element 7P3a are preferably 5 μm or less, and more preferably 2 μm or less.

[0081] As shown in Figure 10, one end of each individual electrode 7Da in the longitudinal direction along the X-axis is connected to an individual wiring section 73a for applying a drive voltage Com. The individual wiring section 73a is provided so as to short-circuit the first individual electrode 7D1 and the second individual electrode 7D2. Specifically, the individual wiring section 73a has a first wiring section 731a, a second wiring section 732a, a third wiring section 733a, a fourth wiring section 734, and a fifth wiring section 735. The first wiring section 731a is provided above the third thin-film piezoelectric body 7P3a. The second wiring section 732a branches off from the first wiring section 731a and extends in the direction along the Z-axis so as to penetrate the first thin-film piezoelectric body 7P1a and the third thin-film piezoelectric body 7P3a, and is connected to the first individual electrode 7D1a. The second wiring section 732a penetrates the contact hole H1a that penetrates the first thin-film piezoelectric element 7P1a and the third thin-film piezoelectric element 7P3a. The third wiring section 733a branches off from the first wiring section 731a, extends along the Z-axis so as to penetrate the third thin-film piezoelectric element 7P3a, and connects to the second individual electrode 7D2a. Specifically, the third wiring section 733a is provided so as to penetrate the contact hole H2a that penetrates the third thin-film piezoelectric element 7P3a. As can be seen from Figure 9, when viewed along the Y-axis, the second wiring section 732a is located between the fourth wiring section 734 and the third wiring section 733a.

[0082] As can be seen from Figure 5, the length T32a of the second wiring section 732a in the direction along the Z axis is longer than the length T33a of the third wiring section 733a in the direction along the Z axis.

[0083] The common wiring section 74 in the second embodiment differs from the common wiring section 74 in the first embodiment in that it is provided in such a way as to short-circuit the two common electrodes 7C. Specifically, the common wiring section 74 in the second embodiment differs from the common wiring section 74 in the first embodiment in that it has a sixth wiring section 746a instead of a sixth wiring section 746. The sixth wiring section 746a is connected to the second common electrode 7C2a at its end in the Z1 direction, to the first common electrode 7C1 at the position of the Z1 direction plane of the second thin-film piezoelectric material 7P2 in the Z axis, and to the seventh wiring section 747 at its end in the Z2 direction.

[0084] Furthermore, as can be seen from Figure 9, in a plan view, the third wiring section 733a does not overlap with the first common electrode 7C1a.

[0085] 2-2. Summary of the Second Embodiment The following is a summary of the liquid discharge head 1a in the second embodiment. The liquid discharge head 1a consists of a pressure chamber substrate 14, a diaphragm 15, a first individual electrode 7D1a, a first thin-film piezoelectric body 7P1a, a first common electrode 7C1a, a second thin-film piezoelectric body 7P2a, a second individual electrode 7D2a, a third thin-film piezoelectric body 7P3a, and a second common electrode 7C2a, which are stacked in this order from bottom to top along the Z-axis. The first set consists of the first individual electrode 7D1a and the second individual electrode 7D2a, and the second set consists of the first common electrode 7C1a and the second common electrode 7C2a. The first set consists of multiple individual electrodes 7Da, and the second set consists of multiple common electrodes 7C. According to the second embodiment, since three thin-film piezoelectric elements 7Pa are stacked, the amount of displacement per unit voltage can be increased compared to the embodiment in which two thin-film piezoelectric elements 7Pa are stacked.

[0086] Furthermore, the individual wiring section 73a includes a first wiring section 731a provided above the third thin-film piezoelectric body 7P3a, a second wiring section 732a branching from the first wiring section 731a, extending in a direction along the Z-axis so as to penetrate the first thin-film piezoelectric body 7P1a, and connecting to the first individual electrode 7D1a, and a third wiring section 733a branching from the first wiring section 731a, extending in a direction along the Z-axis, and connecting to the second individual electrode 7D2a. According to the second embodiment, the first wiring section 731a is used as a common wiring for the first individual electrode 7D1a and the second individual electrode 7D2a, while the second wiring section 732a can supply a drive voltage Com to the first individual electrode 7D1a, and the third wiring section 733a can supply a drive voltage Com to the second individual electrode 7D2a.

[0087] Furthermore, no other thin-film piezoelectric material 7Pa is formed on the upper side of the second common electrode 7C2a. According to the second embodiment, since three thin-film piezoelectric elements 7Pa are stacked, the amount of displacement per unit voltage can be increased compared to the embodiment in which two thin-film piezoelectric elements 7Pa are stacked.

[0088] The first individual electrode 7D1a and the second individual electrode 7D2a are multiple individual electrodes 7Da, and the first common electrode 7C1a and the second common electrode 7C2a are multiple common electrodes 7Ca. According to the second embodiment, a driving voltage Com and a reference voltage VBS can be applied to three thin-film piezoelectric elements 7Pa using four electrodes.

[0089] Furthermore, the multiple individual electrodes 7Da consist of two individual electrodes 7Da, and the length LD1a along the X-axis of the first individual electrode 7D1a, which is the individual electrode 7Da located relatively lower than the other individual electrode 7Da, is longer than the length LD2a along the X-axis of the second individual electrode 7D2a, which is the other individual electrode 7Da. According to the second embodiment, similar to the first embodiment, compared to the embodiment in which the length LD2a is longer than the length LD1a, it is possible to maintain the discharge characteristics of the liquid discharge head 1a while suppressing an increase in the manufacturing process of the piezoelectric element 7a.

[0090] 3. Third Embodiment In the first and second embodiments, the uppermost electrode of the piezoelectric element 7 was a common electrode 7C, but it may also be an individual electrode 7D. However, if the uppermost electrode of the piezoelectric element 7 is an individual electrode 7D, there will be areas where the thin-film piezoelectric material 7P is exposed. When the thin-film piezoelectric material 7P is exposed, the discharge characteristics of the thin-film piezoelectric material 7P may deteriorate due to moisture in the atmosphere, etc. Therefore, the piezoelectric element 7b in the third embodiment has a protective film that protects the thin-film piezoelectric material 7P from moisture. The third embodiment will be described below.

[0091] 3-1. Piezoelectric element 7b in the third embodiment Figure 11 is a cross-sectional view of a portion of the liquid discharge head 1b in the third embodiment. In Figure 11, the cross-section is shown along line IV-IV in Figure 2 when the liquid discharge head 1 shown in Figure 2 is replaced with the liquid discharge head 1b. Figure 12 is an enlarged cross-sectional view of region AR when the liquid discharge head 1 shown in Figure 3 is replaced with the liquid discharge head 1b. The liquid discharge head 1b differs from the liquid discharge head 1 in that it has a piezoelectric element 7b instead of the piezoelectric element 7.

[0092] The piezoelectric element 7b differs from the piezoelectric element 7 in the first embodiment in that it does not have a fourth thin-film piezoelectric body 7P4 and a third common electrode 7C3, and instead of a third thin-film piezoelectric body 7P3, it has a third thin-film piezoelectric body 7P3b and a water-resistant protective film 7G1. In the third embodiment, the first thin-film piezoelectric body 7P1, the second thin-film piezoelectric body 7P2, and the third thin-film piezoelectric body 7P3b may be referred to simply as thin-film piezoelectric body 7P without distinction.

[0093] The third thin-film piezoelectric element 7P3b differs from the third thin-film piezoelectric element 7P3b in that, as shown in Figure 12, it is formed to cover the second common electrode 7C2 at its end in the X1 direction.

[0094] The water-resistant protective film 7G1 is laminated on the upper side of the second individual electrode 7D2. More specifically, in the third embodiment, the water-resistant protective film 7G1 is formed to cover the second individual electrode 7D2, the third thin-film piezoelectric element 7P3, and the second common electrode 7C2 and the first common electrode 7C1. However, the water-resistant protective film 7G1 only needs to be formed to cover at least the third thin-film piezoelectric element 7P3.

[0095] The material for the water-resistant protective film 7G1 can be any material that has moisture resistance, for example, silicon oxide (SiO₂) x ), tantalum oxide (TaO x ), aluminum oxide (AlO x It is preferable to use inorganic insulating materials such as ), and in particular, aluminum oxide (AlO), which is an inorganic amorphous material. xFor example, it is preferable to use alumina (Al2O3). When aluminum oxide is used as the material for the water-resistant protective film 7G1, even if the film thickness of the water-resistant protective film 7G1 is relatively thin, around 100 nm, it is possible to sufficiently prevent moisture permeation in high-humidity environments.

[0096] In the third embodiment, one end of each individual electrode 7D in the longitudinal direction along the X-axis is connected to an individual wiring section 73b for applying a drive voltage Com. The individual wiring section 73b differs from the individual wiring section 73 in that it does not have a third wiring section 733, has a first wiring section 731b instead of a first wiring section 731, and has a second wiring section 732b instead of a second wiring section 732.

[0097] The first wiring section 731b is located above the third thin-film piezoelectric element 7P3 and connects to the second individual electrode 7D2 at its end in the X2 direction. That is, the first wiring section 731b functions as a lead wire for the second individual electrode 7D2. The second wiring section 732b branches off from the first wiring section 731 and extends along the Z-axis, penetrating the second thin-film piezoelectric element 7P2 and the third thin-film piezoelectric element 7P3, and connects to the first individual electrode 7D1. Specifically, the second wiring section 732b penetrates the contact hole H1b that penetrates the second thin-film piezoelectric element 7P2 and the third thin-film piezoelectric element 7P3.

[0098] The common wiring section 74 in the third embodiment differs from the common wiring section 74 in the first embodiment in that it is provided in such a way as to short-circuit the two common electrodes 7C. The common wiring section 74 in the third embodiment also differs from the common wiring section 74 in the first embodiment in that it has a sixth wiring section 746b instead of a sixth wiring section 746. The sixth wiring section 746b is connected to the second common electrode 7C2 at its end in the Z1 direction and to the first common electrode 7C1 and the seventh wiring section 747 at its end in the Z2 direction.

[0099] 3-2. Summary of the Third Embodiment In the third embodiment, the liquid discharge head 1b, like the liquid discharge head 1 in the first embodiment, has three thin-film piezoelectric elements 7P stacked on top of each other, so the amount of displacement per unit voltage can be increased compared to the embodiment in which two thin-film piezoelectric elements 7P are stacked. In the first embodiment, the liquid discharge head 1 does not need to have a water-resistant protective film 7G1 because the third common electrode 7C3 also functions as a water-resistant protective film compared to the liquid discharge head 1b. Similarly, in the second embodiment, the liquid discharge head 1a does not need to have a water-resistant protective film 7G1 because the second common electrode 7C2a also functions as a water-resistant protective film compared to the liquid discharge head 1b.

[0100] 4. Fourth Embodiment In the fourth embodiment, in a plan view, the cross-sectional area of ​​the second wiring section 732 of the individual wiring section 73 is made larger than the cross-sectional area of ​​the third wiring section 733. The fourth embodiment will be described below.

[0101] Figure 13 is an enlarged cross-sectional view of region AR when the liquid discharge head 1 shown in Figure 3 is replaced with the liquid discharge head 1c in the fourth embodiment. Figure 14 is a diagram showing the planar arrangement of the individual electrodes 7D and the common electrode 7C in the fourth embodiment. The liquid discharge head 1c differs from the liquid discharge head 1 in that it has an individual wiring section 73c instead of the individual wiring section 73. The individual wiring section 73c differs from the individual wiring section 73 in that it has a second wiring section 732c instead of the second wiring section 732, and a third wiring section 733c instead of the third wiring section 733.

[0102] As shown in Figure 13, the length T32 of the second wiring section 732c in the direction along the Z axis is longer than the length T33 of the third wiring section 733c in the direction along the Z axis. Also, as shown in Figure 14, in a plan view, the cross-sectional area S32c of the second wiring section 732c is larger than the cross-sectional area S33c of the third wiring section 733c. In the fifth embodiment, the width of the second wiring section 732c in the direction along the Y axis and the width of the third wiring section 733c in the direction along the Y axis are approximately the same, and as shown in Figure 13, the width D32 of the second wiring section 732c in the direction along the X axis is longer than the width D33 of the third wiring section 733c in the direction along the X axis.

[0103] In the fourth embodiment described above, the length T32 is longer than the length T33, and the cross-sectional area S32c is larger than the cross-sectional area S33c. Generally, the resistance of a wire increases with increasing wire length and decreases with increasing cross-sectional area. Furthermore, the voltage drop increases with increasing resistance. As can be seen from Figure 13, since length T32 is longer than length T33, the resistance of the second wiring section 732 in the first embodiment is greater than the resistance of the third wiring section 733 in the first embodiment. Therefore, in the first embodiment, the voltage applied to the first individual electrode 7D1 is lower than the voltage applied to the second individual electrode 7D2. Thus, in the fourth embodiment, since the cross-sectional area S32c is larger than the cross-sectional area S33c, the voltage applied to the first individual electrode 7D1 and the voltage applied to the second individual electrode 7D2 can be made closer to the same value compared to the first embodiment.

[0104] In addition, the fourth embodiment is a configuration in which the cross-sectional area S32c is set to be larger than the cross-sectional area S33c for the individual wiring section 73 of the first embodiment, but the fourth embodiment can also be applied to the individual wiring section 73a of the second embodiment. Specifically, in a plan view, the cross-sectional area of ​​the second wiring section 732a of the individual wiring section 73a of the second embodiment may be larger than the cross-sectional area of ​​the third wiring section 733a of the individual wiring section 73a.

[0105] 5. Fifth Embodiment The fifth embodiment differs from the above-described embodiments in that it is provided to connect individual wiring to a plurality of individual electrodes 7D. The fifth embodiment will be described below.

[0106] Figure 15 is an enlarged cross-sectional view of region AR when the liquid discharge head 1 shown in Figure 3 is replaced with the liquid discharge head 1d in the fifth embodiment. Figure 16 is a diagram showing the planar arrangement of the individual electrodes 7D and the common electrode 7C in the fifth embodiment. The liquid discharge head 1c differs from the liquid discharge head 1 in that it has a piezoelectric element 7d instead of the piezoelectric element 7, and an individual wiring section 73d instead of the individual wiring section 73.

[0107] The piezoelectric element 7d differs from the piezoelectric element 7 in that it has a first individual electrode 7D1d instead of the first individual electrode 7D1. As shown in Figure 16, the first individual electrode 7D1d is formed in an L-shape. Specifically, as shown in Figure 16, the first individual electrode 7D1d has a first electrode portion 7D1da and a second electrode portion 7D1db. The first electrode portion 7D1da extends in the direction along the X-axis and connects to the second electrode portion 7D1db at its end in the X1 direction. The second electrode portion 7D1db extends in the direction along the Y-axis. In the following description, the first individual electrode 7D1d and the second individual electrode 7D2 may be referred to simply as individual electrode 7Dd without distinction. In the fifth embodiment, the first individual electrode 7D1d is formed in an L-shape, but the second individual electrode 7D2 may also be formed in an L-shape.

[0108] The individual wiring section 73d includes a first wiring section 731d1, a first wiring section 731d2, a second wiring section 732d, a third wiring section 733d, a fourth wiring section 734d1, a fourth wiring section 734d2, a fifth wiring section 735d1, and a fifth wiring section 735d2. The first wiring section 731d1, the second wiring section 732d, the fourth wiring section 734d1, and the fifth wiring section 735d1 are wiring for supplying a drive voltage Com to the first individual electrode 7D1d. The first wiring section 731d2, the third wiring section 733d, the fourth wiring section 734d2, and the fifth wiring section 735d2 are wiring for supplying a drive voltage Com to the second individual electrode 7D2. As can be seen from Figures 15 and 16, the Y-axis position of each wire in the individual wiring section 73d that supplies the drive voltage Com to the first individual electrode 7D1d is different from the Y-axis position of each wire that supplies the drive voltage Com to the second individual electrode 7D2.

[0109] The cross-sectional view shown in Figure 15 shows the cross-section of the Y-axis position of each wiring in the individual wiring section 73d that supplies the drive voltage Com to the second individual electrode 7D2. In Figure 15, for the sake of ease of understanding each element of the individual wiring section 73d, the width of the first wiring section 731d1 along the Z-axis is shown to be shorter than the width of the first wiring section 731d2 along the Z-axis. However, in reality, the width of the first wiring section 731d1 along the Z-axis may be the same as or different from the width of the first wiring section 731d2 along the Z-axis. The same applies to the relationship between the width of the fourth wiring section 734d1 along the X-axis and the width of the fourth wiring section 734d2 along the X-axis, and the relationship between the width of the fifth wiring section 735d1 along the Z-axis and the width of the fifth wiring section 735d2 along the Z-axis.

[0110] The first wiring section 731d1 and the first wiring section 731d2 extend in the direction along the X-axis and are provided above the fourth thin-film piezoelectric element 7P4. The second wiring section 732d extends in the direction along the Z-axis and is provided to pass through the contact hole H1d that penetrates the second thin-film piezoelectric element 7P2 and the fourth thin-film piezoelectric element 7P4. The second wiring section 732d connects to the X2 end of the first wiring section 731d1 at its Z1 end and to the second electrode section 7D1db at its Z2 end. The third wiring section 733d extends in the direction along the Z-axis and is provided to pass through the contact hole H2d that penetrates the fourth thin-film piezoelectric element 7P4. The third wiring section 733d connects to the X2 end of the first wiring section 731d2 at its Z1 end and to the second individual electrode 7D2 at its Z2 end.

[0111] The fourth wiring section 734d1 and the fourth wiring section 734d2 extend along the Z-axis direction along the X1 direction side surfaces of the second thin-film piezoelectric body 7P2 and the fourth thin-film piezoelectric body 7P4. The fourth wiring section 734d1 connects to the first wiring section 731d1 at its Z1 direction end and to the fifth wiring section 735d1 at its Z2 direction end. The fourth wiring section 734d2 connects to the first wiring section 731d2 at its Z1 direction end and to the fifth wiring section 735d2 at its Z2 direction end. The fifth wiring sections 735d1 and 735d2 are provided on the Z1 direction-facing surface of the diaphragm 15 and are connected to the wiring 70. Accordingly, the first individual electrode 7D1d and the second individual electrode 7D2 are electrically connected to the drive circuit 20 via the individual wiring section 73d.

[0112] In the fifth embodiment, the individual wiring section 73d is provided to connect individual wiring to the two individual electrodes 7Dd. Therefore, in the fifth embodiment, different drive voltages Com can be supplied to each of the two individual electrodes 7Dd. For example, if the total length of the wiring for supplying the drive voltage Com to the first individual electrode 7D1d is different from the total length of the wiring for supplying the drive voltage Com to the second individual electrode 7D2, the voltage applied to the two individual electrodes 7Dd may differ even if the same drive voltage Com is to be supplied to both individual electrodes 7Dd. Therefore, in the fifth embodiment, by supplying different drive voltages Com to each of the two individual electrodes 7Dd, the voltage applied to the first individual electrode 7D1d and the voltage applied to the second individual electrode 7D2 can be made closer to the same.

[0113] In addition, the fifth embodiment is configured to connect individual wiring to the two individual electrodes 7D of the first embodiment, but the fifth embodiment can also be applied to the second embodiment. Specifically, it may be configured to connect individual wiring to the two individual electrodes 7Da of the second embodiment.

[0114] 6. Sixth Embodiment Figure 17 is a cross-sectional view of a portion of the liquid discharge head 1e in the sixth embodiment. The cross-sectional view shown in Figure 17 is the cross-section along line IV-IV in Figure 2 when the liquid discharge head 1 shown in Figure 2 is replaced with the liquid discharge head 1e. The liquid discharge head 1e differs from the liquid discharge head 1 in that it has a piezoelectric element 7e instead of the piezoelectric element 7.

[0115] The piezoelectric element 7e differs from the piezoelectric element 7 in that it has a first thin-film piezoelectric element 7P1e instead of the first thin-film piezoelectric element 7P1, a second thin-film piezoelectric element 7P2e instead of the second thin-film piezoelectric element 7P2, a third thin-film piezoelectric element 7P3e instead of the third thin-film piezoelectric element 7P3, and a fourth thin-film piezoelectric element 7P4e instead of the fourth thin-film piezoelectric element 7P4.

[0116] As shown in Figure 17, the second thin-film piezoelectric element 7P2e is formed to cover the first thin-film piezoelectric element 7P1e and the first individual electrode 7D1 at its ends in the Y1 and Y2 directions. As shown in Figure 17, the fourth thin-film piezoelectric element 7P4e is formed to cover the third thin-film piezoelectric element 7P3e and the second individual electrode 7D2 at its ends in the Y1 and Y2 directions.

[0117] 7. Variations Each of the forms exemplified above can be modified in various ways. Specific examples of modifications that can be applied to each of the aforementioned forms are given below. Two or more forms arbitrarily selected from the following examples can be combined as appropriate, provided they do not contradict each other.

[0118] 7-1. First variation In each of the embodiments described above, the common wiring section 74 is provided so as to short-circuit a plurality of common electrodes 7C, but it is not limited to this. For example, in the first modified example, the common wiring section 74 may be provided so as to connect individual wiring to a plurality of common electrodes 7C. By providing the common wiring section 74 so as to connect individual wiring to a plurality of common electrodes 7C, for example, in the first embodiment, the reference voltage VBS applied to the first common electrode 7C1, the second common electrode 7C2, and the third common electrode 7C3 can be set to be different.

[0119] 7-2. Second Variation Inclusive of the above embodiments, the piezoelectric element 7 may have 3 to n thin-film piezoelectric elements 7P and n+1 electrodes. The n+1 electrodes may alternate between common electrodes 7C and individual electrodes 7D from bottom to top. For example, the piezoelectric element 7 may have 5 thin-film piezoelectric elements 7P and 6 electrodes. There are two possible configurations for the 6 electrodes: The first configuration is one in which the lowest electrode is a common electrode 7C. The second configuration is one in which the lowest electrode is an individual electrode 7D. When the uppermost electrode is an individual electrode 7D, it is preferable that the uppermost thin-film piezoelectric element 7P is covered with a water-resistant protective film, as described in the third embodiment.

[0120] 7-3. Third Variation In the embodiments described above, a serial-type liquid dispensing device in which a transporter 931 equipped with a liquid dispensing head 1 is reciprocated has been illustrated. However, this disclosure can also be applied to a line-type liquid dispensing device in which a plurality of nozzles N are distributed across the entire width of the medium M.

[0121] 7-4. Other variations The liquid dispensing apparatus described above can be used in various devices, including not only equipment dedicated to printing, but also facsimile machines and photocopiers. However, the applications of the liquid dispensing apparatus of this disclosure are not limited to printing. For example, a liquid dispensing apparatus that dispenses a colorant solution can be used as a manufacturing apparatus for forming color filters for liquid crystal display devices. Also, a liquid dispensing apparatus that dispenses a conductive material solution can be used as a manufacturing apparatus for forming wiring and electrodes on a wiring board. [Explanation of symbols]

[0122] 1,1a,1b,1c,1d,1e…Liquid dispensing head, 7…Piezoelectric element, 7C1,7C1a…First common electrode, 7C2,7C2a…Second common electrode, 7C3…Third common electrode, 7D1,7D1a,7D1d…First individual electrode, 7D1da…First electrode section, 7D1db…Second electrode section, 7D2,7D2a…Second individual electrode, 7G1…Water-resistant protective film, 7P1,7P1a,7P1e…First thin-film piezoelectric, 7P2,7P2a,7P2e…Second thin-film piezoelectric, 7P3,7P3a,7P3b,7P3e…Third thin-film piezoelectric, 7P4,7P4e…Fourth thin-film piezoelectric Body, 7a, 7b, 7d, 7e... Piezoelectric element, 11... Nozzle plate, 12... Vibration absorber, 13... Flow channel substrate, 14... Pressure chamber substrate, 15... Diaphragm, 16... Wiring substrate, 16B... Bump, 17... Housing section, 20... Drive circuit, 21... External wiring, 22, 23, 70... Wiring, 73, 73a, 73b, 73c, 73d... Individual wiring section, 74... Common wiring section, 90... Liquid container, 91... Control unit, 92... Conveyor mechanism, 93... Moving mechanism, 100... Liquid discharge device, 131... Supply channel, 132... Communicating channel, 133... Supply liquid chamber, 151... First layer, 152... Second layer, 17 1...Inlet, 731, 731a, 731b, 731d1, 731d2...First wiring section, 732, 732a, 732b, 732c, 732d...Second wiring section, 733, 733a, 733c, 733d...Third wiring section, 734, 734d1, 734d2...Fourth wiring section, 735, 735d1, 735d2...Fifth wiring section, 746, 746a, 746b...Sixth wiring section, 747...Seventh wiring section, 748...Eighth wiring section, 910...Voltage application circuit, 931...Conveyor body, 932...Conveyor belt, AR...Area, C...Pressure chamber, Com...Drive voltage, EK...Intermediate power Pressure, EM...Minimum voltage, EN...Maximum voltage, Ea...Applied voltage, Ek...Intermediate voltage, Em...Minimum voltage, En...Maximum voltage, H1, H1a, H1b, H1d, H2, H2a, H2d...Contact hole, HO...Through hole, L1...First row, L2...Second row, M...Media, N...Nozzle, R...Liquid storage chamber, Ra, Rb...Space, S32, S32c, S33, S33c...Cross-sectional area, T1...Contraction period, T2...Expansion period, TP1, TP1a, TP2, TP2a, TP3, TP3a, TP4...Thickness, Tu...Unit period, VBS...Reference voltage, WCom...Drive waveform.

Claims

1. A liquid dispensing head, A pressure chamber substrate having multiple pressure chambers arranged in the direction of the arrangement, The diaphragm and First electrode and, First thin-film piezoelectric material, The second electrode and The second thin-film piezoelectric material, The third electrode and A third thin-film piezoelectric material, The fourth electrode and the other are stacked in this order from bottom to top along the arrangement direction and the stacking direction that intersects the extension direction that intersects the arrangement direction, When the set of the first electrode and the third electrode is designated as the first set, and the set of the second electrode and the fourth electrode is designated as the second set, One of the first set and the second set is a set of multiple common electrodes that are provided in common to the multiple pressure chambers and to which a reference voltage that does not change over time is applied, A liquid discharge head characterized in that the other of the first set and the second set is a set of multiple individual electrodes that are individually provided for the multiple pressure chambers so as to extend in the extending direction, and to which a drive voltage that changes over time is applied.

2. A common wiring section for applying the reference voltage to the plurality of common electrodes included in one of the sets, The liquid dispensing head according to claim 1, further comprising: individual wiring sections for applying the drive voltage to the plurality of individual electrodes included in the other set.

3. The liquid dispensing head according to claim 2, characterized in that the individual wiring section is provided such that it short-circuits the plurality of individual electrodes included in the other set.

4. The aforementioned individual wiring section is A first wiring section provided above the third thin-film piezoelectric material, A second wiring section branches off from the first wiring section, extends in the stacking direction so as to penetrate the second thin-film piezoelectric material, and connects to the second electrode, The liquid discharge head according to claim 3, further comprising a third wiring section that branches off from the first wiring section, extends in the stacking direction, and connects to the fourth electrode.

5. The length of the second wiring section in the stacking direction is longer than the length of the third wiring section in the stacking direction. The liquid discharge head according to claim 4, characterized in that the cross-sectional area of ​​the second wiring portion when viewed from the stacking direction is larger than the cross-sectional area of ​​the third wiring portion when viewed from the stacking direction.

6. The aforementioned individual wiring section is A first wiring section provided above the third thin-film piezoelectric material, A second wiring section branches off from the first wiring section, extends in the stacking direction so as to penetrate the first thin-film piezoelectric material, and connects to the first electrode, The liquid dispensing head according to claim 3, further comprising a third wiring section that branches off from the first wiring section, extends in the stacking direction, and connects to the third electrode.

7. The length of the second wiring section in the stacking direction is longer than the length of the third wiring section in the stacking direction. The liquid dispensing head according to claim 6, characterized in that the cross-sectional area of ​​the second wiring portion when viewed from the stacking direction is larger than the cross-sectional area of ​​the third wiring portion when viewed from the stacking direction.

8. The liquid dispensing head according to claim 2, characterized in that the common wiring section is provided such that it short-circuits the plurality of common electrodes included in one of the sets.

9. On the upper side of the fourth electrode, A fourth thin-film piezoelectric material, The fifth electrode and the others are further stacked in this order. The liquid dispensing head according to claim 1, characterized in that no other thin-film piezoelectric material is formed on the upper side of the fifth electrode.

10. The first electrode, the third electrode, and the fifth electrode are the plurality of common electrodes, The liquid dispensing head according to claim 9, characterized in that the second electrode and the fourth electrode are the plurality of individual electrodes.

11. The liquid dispensing head according to claim 1, characterized in that no other thin-film piezoelectric material is formed on the upper side of the fourth electrode.

12. The first electrode and the third electrode are the plurality of individual electrodes, The liquid dispensing head according to claim 11, characterized in that the second electrode and the fourth electrode are the plurality of common electrodes.

13. The aforementioned plurality of individual electrodes consist of two individual electrodes, The liquid dispensing head according to claim 1, characterized in that the length of one of the two individual electrodes located relatively lower along the extending direction is longer than the length of the other individual electrode along the extending direction.

14. A liquid dispensing head according to any one of claims 1 to 13, A liquid dispensing device characterized by having a control unit that controls the dispensing operation from the liquid dispensing head.

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