Liquid ejecting head and liquid ejecting apparatus

Abstract

This application provides a liquid jet head and a liquid jetting device capable of detecting residual vibrations after liquid jetting with high precision. The liquid jet head includes: a plurality of nozzles arranged along a first direction; a first piezoelectric element; a second piezoelectric element; a pressure chamber driven by the first piezoelectric element to impart pressure for jetting liquid from the nozzles; and a detection chamber for detecting residual vibrations caused by the pressure of the liquid imparted by the pressure chamber by the second piezoelectric element. In top view, the width of the active portion of the second piezoelectric element (i.e., the second active portion) in the first direction is greater than the width of the active portion of the first piezoelectric element (i.e., the first active portion) in the first direction.

Description

Technical Field

[0001] This invention relates to a liquid ejector head that ejects liquid from a nozzle and a liquid ejection device equipped with a liquid ejector head, and particularly to an inkjet recording head that ejects ink as a liquid and an inkjet recording device. Background Technology

[0002] Liquid ejection devices, such as inkjet printers and plotters, include liquid ejection heads that eject liquids, such as ink stored in ink cartridges or ink cans, into droplets. The liquid ejection head includes: a nozzle for ejecting liquid; a pressure chamber connected to the nozzle; and a drive element that causes pressure fluctuations in the liquid within the pressure chamber. The liquid ejection head generates these pressure fluctuations through the drive element, causing droplets to be ejected from the nozzle. Furthermore, the liquid ejection head can detect residual vibrations in the liquid within the pressure chamber after ejection to determine nozzle blockage or liquid viscosity (see, for example, Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-147363

[0004] However, in Patent Document 1, the following problem exists: since the same piezoelectric element and the same pressure chamber are used for driving the liquid jet and detecting the residual vibration after the liquid jet, therefore, if the test Figure 1 When liquid is being sprayed while residual vibration is being detected simultaneously, the driving frequency used for liquid spraying is sometimes limited, preventing the achievement of sufficient throughput.

[0005] Therefore, although it was considered to separate the pressure chamber and piezoelectric element for residual vibration detection from the pressure chamber and piezoelectric element for liquid injection, the structure of the piezoelectric element for detection in this case was not fully explored, resulting in the problem of inefficient detection. Summary of the Invention

[0006] The present invention, which solves the above-mentioned technical problems, provides a liquid injection head characterized by comprising: a plurality of nozzles arranged along a first direction; a first piezoelectric element; a second piezoelectric element; a pressure chamber driven by the first piezoelectric element to impart pressure for injecting liquid from the nozzles; and a detection chamber for detecting residual vibrations of the pressure of the liquid imparted by the pressure chamber by the second piezoelectric element. In a top view, the width of the active portion of the second piezoelectric element (i.e., the second active portion) in the first direction is greater than the width of the active portion of the first piezoelectric element (i.e., the first active portion) in the first direction.

[0007] Another aspect of the present invention is a liquid injection head, characterized by comprising: a plurality of nozzles arranged along a first direction; a first piezoelectric element; a second piezoelectric element; a pressure chamber driven by the first piezoelectric element to impart pressure for injecting liquid from the nozzles; and a detection chamber for detecting residual vibrations of the pressure of the liquid imparted by the pressure chamber by the second piezoelectric element, wherein, in top view, the area of ​​the active portion of the second piezoelectric element, i.e., the second active portion, is larger than the area of ​​the active portion of the first piezoelectric element, i.e., the first active portion.

[0008] Furthermore, another aspect of the present invention is a liquid injection device, characterized in that it comprises a liquid injection head as described in any of the above-described aspects and a liquid storage section for supplying liquid to the liquid injection head. Attached Figure Description

[0009] Figure 1 This is an exploded perspective view of the liquid injection head according to Embodiment 1.

[0010] Figure 2 This is a top view of the pressure chamber substrate and the connecting plate involved in Embodiment 1.

[0011] Figure 3 This is a cross-sectional view of the liquid injection head according to Embodiment 1.

[0012] Figure 4 This is a top view of the first piezoelectric element, the second piezoelectric element, and the pressure chamber substrate involved in Embodiment 1.

[0013] Figure 5 This is a cross-sectional view of the first piezoelectric element and the pressure chamber substrate involved in Embodiment 1.

[0014] Figure 6 This is a cross-sectional view of the second piezoelectric element and the pressure chamber substrate involved in Embodiment 1.

[0015] Figure 7 This is a cross-sectional view of the first piezoelectric element and the pressure chamber substrate according to Embodiment 1.

[0016] Figure 8 This is a cross-sectional view of the second piezoelectric element and the pressure chamber substrate involved in Embodiment 1.

[0017] Figure 9 This is a top view of the first piezoelectric element, the second piezoelectric element, and the pressure chamber substrate involved in Embodiment 2.

[0018] Figure 10 This is a diagram showing the schematic configuration of a liquid injection device according to one embodiment.

[0019] Explanation of reference numerals in the attached figures

[0020] H…Liquid jet head, S…Media, Tin…Supply pipe, Tout…Discharge pipe, 1…Liquid jetting device, 3…Liquid storage section, 4…Control section, 5…Transporting mechanism, 6…Moving mechanism, 7…Pump, 10…Pressure chamber base plate, 11…Partition wall, 12…Pressure chamber, 13…Ink supply path, 14…Absorption chamber, 15…Detection chamber, 16A, 16B…Flow path, 17…Partition wall, 20…Nozzle plate, 20a…Nozzle surface, 21…Nozzle, 30…Protective base Plate, 31A~31C…receiving part, 32…opening part, 33A, 33B…flow path, 40…shell, 41A, 41B…flow path, 42…supply port, 43…discharge port, 44…through hole, 50…vibrating plate, 50a…elastic membrane, 50b…insulating membrane, 51…first vibrating plate, 52…second vibrating plate, 53…third vibrating plate, 61…first lower electrode, 62…second lower electrode, 63…third lower electrode, 71…first piezoelectric layer, 7 1a…First recess, 72…Second piezoelectric layer, 72a…Second recess, 73…Third piezoelectric layer, 81…First upper electrode, 82…Second upper electrode, 83…Third upper electrode, 91A…First independent lead electrode, 91B…First common lead electrode, 92A…Second independent lead electrode, 92B…Second common lead electrode, 93…First extension portion, 94…Second extension portion, 100A, 100B…Common liquid chamber, 110…Flexible Substrate, 111…control circuit, 120…connecting plate, 121A, 121B…flow path, 122…discharge connecting path, 123…connecting path, 124…recycling path, 130A, 130B…plastic substrate, 131…sealing film, 132…fixed substrate, 133…opening, 134…plastic part, 301…first piezoelectric element, 302…second piezoelectric element, 303…third piezoelectric element, 311…first active part, 312…second active part. Detailed Implementation

[0021] The present invention will now be described in detail based on embodiments. However, the following description is an illustration of one aspect of the present invention and can be modified arbitrarily within the scope of the present invention. Components labeled with the same reference numerals in each figure are shown as the same component and their descriptions are appropriately omitted. Furthermore, in each figure, X, Y, and Z represent three spatial axes that are orthogonal to each other. In this specification, the directions along these axes will be defined as the X direction, Y direction, and Z direction. The direction in which the arrows in each figure point will be defined as the positive (+) direction, and the opposite direction of the arrows will be defined as the negative (-) direction. Additionally, the Z direction indicates the vertical direction, the +Z direction indicates vertically downward, and the -Z direction indicates vertically upward. Furthermore, the directions of the three spatial axes, which are not limited to positive and negative directions, will be described as the X-axis direction, Y-axis direction, and Z-axis direction. Furthermore, in each of the following embodiments, as an example, the "first direction" will be defined as the X-axis direction, and the "jet direction" will be defined as the +Z direction. Additionally, "down" will be the +Z direction, and "up" will be the -Z direction. Furthermore, the view along the Z-axis direction will be referred to as "top view."

[0022] Implementation Method 1

[0023] Figure 1 This is an exploded perspective view of the liquid injection head H according to Embodiment 1 of the present invention. Figure 2 This is a top view of the pressure chamber base plate 10 and the connecting plate 120 along the +Z direction. Figure 3 It includes Figure 2 A cross-sectional view of the liquid jet head H along line AA′. Figure 4 This is a top view of the first piezoelectric element 301, the second piezoelectric element 302, and the pressure chamber substrate 10 viewed along the +Z direction. Figure 5 yes Figure 4 BB′ line section view. Figure 6 yes Figure 4 A cross-sectional view along the CC' line. Figure 7 yes Figure 4 DD′ line section view. Figure 8 yes Figure 4 EE′ line section view.

[0024] The liquid ejector head H is configured as the ink ejection head in the printer. Ink is directed to the liquid ejector head H, and a portion of it is ejected from the nozzle 21 toward an external medium, such as printing media. Since the ink is circulated, ink not ejected from the nozzle 21 is discharged from the liquid ejector head H. Therefore, in this specification, the terms "supply side" and "discharge side" are sometimes used. "Supply side" refers to the portion of the liquid flow path upstream of the pressure chamber described later. Additionally, the portion associated with the portion upstream of the pressure chamber is sometimes referred to as the "supply side." "Discharge side" refers to the portion of the liquid flow path downstream of the pressure chamber 12.

[0025] It should be noted that the "discharge side" does not include nozzle 21, which will be described later. Additionally, the portion associated with the part further downstream of pressure chamber 12 is sometimes referred to as the "discharge side." Furthermore, it is sometimes referred to as the "recovery side" instead of the "discharge side." It should be noted that the liquid is not limited to ink; the liquid jet head H can be configured to eject other liquids.

[0026] As shown in the figure, the liquid jet head, with H facing -Z, includes a nozzle plate 20, a connecting plate 120, a pressure chamber base plate 10, a protective base plate 30, and a housing 40 in sequence.

[0027] The pressure chamber substrate 10 is made of, for example, a silicon substrate, a glass substrate, an SOI substrate, or various ceramic substrates.

[0028] On the pressure chamber substrate 10, a plurality of pressure chambers 12 are arranged side by side along the X-axis. The plurality of pressure chambers 12 are arranged in a straight line along the X-axis such that they are in the same position in the Y-axis direction. Two pressure chambers 12 that are adjacent to each other in the X-axis direction are separated by a partition wall 11.

[0029] Multiple pressure chambers 12 are each formed through a through-hole that extends the pressure chamber substrate 10 from its -Z-direction surface to its +Z-direction surface along the Z-axis, and a portion of each pressure chamber 12 is defined by the -Z-direction surface of the connecting plate 120. Here, a "through-hole" refers to a space defined by a side surface connecting the -Z-direction surface to the +Z-direction surface of the pressure chamber substrate 10. This side surface can be inclined relative to the Z-axis direction; that is, the through-hole can also be defined by an inclined surface.

[0030] Furthermore, the pressure chamber substrate 10 has an ink supply path 13 for each pressure chamber 12, which is connected to one end of the pressure chamber 12 in the +Y direction. The ink supply path 13 is defined by a through hole penetrating the pressure chamber substrate 10 along the Z-axis direction, and is formed in the X-axis direction with a width narrower than that of the pressure chamber 12, maintaining a constant flow resistance for ink flowing from upstream into the pressure chamber 12. In other words, the ink supply path 13 functions as a so-called throttling section. It should be noted that the ink supply path 13 is not limited to a configuration that shortens its width in the X-axis direction; its height in the Z-axis direction can also be shortened. The connection point to the ink supply path 13 is referred to as the pressure chamber 12. Furthermore, the surface of the pressure chamber 12 in the -Z direction is defined by the first vibrating plate 51, and the surface of the ink supply path 13 in the -Z direction is defined by the vibrating plate.

[0031] Additionally, the pressure chamber substrate 10 has an absorption chamber 14, which is connected to an end opposite to the end of the ink supply path 13 that communicates with the pressure chamber 12 in the Y-axis direction, i.e., the end in the +Y direction. The absorption chamber 14 is defined by a through hole that penetrates the pressure chamber substrate 10 in the Z-axis direction. That is, the pressure chamber 12 and the absorption chamber 14 are connected via the ink supply path 13. The absorption chamber 14 is continuously arranged along the X-axis direction throughout a plurality of ink supply paths 13. The surface of the absorption chamber 14 in the -Z direction is defined by a third vibrating plate 53. Such an absorption chamber 14 functions as a damper for absorbing vibrations of ink. It should be noted that the absorption chamber 14 is not necessary and may be omitted.

[0032] Furthermore, the pressure chamber substrate 10 has a detection chamber 15 located in the Y-axis direction opposite to the ink supply path 13 of the pressure chamber 12, i.e., in the -Y direction, and separated from the pressure chamber 12 in the Y-axis direction. The detection chamber 15 is defined by a through hole penetrating the pressure chamber substrate 10 along the Z-axis direction and by the surface of the connecting plate 120 facing the -Z direction. That is, the pressure chamber substrate 10 has a partition wall 17 disposed between the pressure chamber 12 and the detection chamber 15, and defines the side surfaces of the pressure chamber 12 and the detection chamber 15 in the Y-axis direction. A plurality of detection chambers 15 are arranged side by side along the X-axis direction. That is, a plurality of detection chambers 15 are arranged in a straight line along the X-axis direction such that they are at the same position in the Y-axis direction. Two detection chambers 15 adjacent to each other in the X-axis direction are separated by a partition wall 11. It should be noted that, in this embodiment, as Figure 5 as well as Figure 6 As shown, the upper surface of the detection chamber 15 facing the -Z direction has a width W2 in the X-axis direction that is the same as the upper surface of the pressure chamber 12 facing the -Z direction in the X-axis direction that has a width W4, and the detection chamber 15 is arranged with the same spacing as the pressure chamber 12 in the X-axis direction. Furthermore, as... Figure 7 as well as Figure 8 As shown, the length L2 of the upper surface of the detection chamber 15 facing the -Z direction in the Y-axis direction is less than the length L4 of the upper surface of the pressure chamber 12 facing the -Z direction in the Y-axis direction. That is, in a top view along the +Z direction, the area of ​​the upper surface of the detection chamber 15 facing the -Z direction is less than the area of ​​the upper surface of the pressure chamber 12 facing the -Z direction. In this embodiment, since the pressure chamber 12 and the detection chamber 15 are provided to penetrate the pressure chamber substrate 10 throughout the Z-axis direction, their heights in the Z-axis direction are the same. Therefore, the volume of the detection chamber 15 is less than the volume of the pressure chamber 12.

[0033] Alternatively, the length L2 of the detection chamber 15 can be set to be the same as the length L4 of the pressure chamber 12. In this case, the width W2 of the detection chamber 15 in the X-axis direction can be set to be smaller than the width W4 of the pressure chamber 12 in the X-axis direction, so that the area of ​​the upper surface of the detection chamber 15 facing the -Z direction when viewed from above in the +Z direction is smaller than the area of ​​the upper surface of the pressure chamber 12 facing the -Z direction, and the volume of the detection chamber 15 is smaller than the volume of the pressure chamber 12. Alternatively, the width of the detection chamber 15 in the X-axis direction and the length in the Y-axis direction can be set to be the same as the pressure chamber 12, and the area and volume of the detection chamber 15 when viewed from above in the +Z direction can be set to be the same as the pressure chamber 12.

[0034] It is worth mentioning that the widths W2 and W4 of the pressure chamber 12 and the lengths L2 and L4 of the detection chamber 15 in the X-axis direction and the Y-axis direction are respectively the largest dimensions of the upper surface in the -Z direction defined by the first vibration plate 51 and the second vibration plate 52.

[0035] Furthermore, flow paths 16A and 16B are formed at both ends of the pressure chamber substrate 10 in the Y-axis direction, namely, on both outer sides of the pressure chamber 12, the absorption chamber 14, and the detection chamber 15. These flow paths 16A and 16B constitute part of the common liquid chambers 100A and 100B that are commonly connected to the plurality of pressure chambers 12. In this embodiment, a common liquid chamber 100A on the supply side and a common liquid chamber 100B on the discharge side are formed in the liquid injection head H, and flow paths 16A constituting part of the common liquid chamber 100A on the supply side and flow paths 16B constituting part of the common liquid chamber 100B on the discharge side are provided on the pressure chamber substrate 10. These flow paths 16A and 16B are provided to penetrate the pressure chamber substrate 10 in the Z-axis direction.

[0036] A connecting plate 120 and a nozzle plate 20 are sequentially stacked on the surface of the pressure chamber substrate 10 facing the +Z direction.

[0037] The connecting plate 120 has flow paths 121A and 121B that constitute a portion of the common liquid chambers 100A and 100B, respectively. Flow path 121A is a flow path that constitutes a portion of the common liquid chamber 100A on the supply side. When viewed along the Z-axis, it extends through the connecting plate 120 in the Z-axis direction and is positioned to overlap with flow path 16A of the pressure chamber substrate 10. Furthermore, when viewed along the Z-axis, flow path 121A extends along the -Y direction and is positioned to overlap with the end of the absorption chamber 14 in the +Y direction. Thus, flow path 121A and the end of the absorption chamber 14 of the pressure chamber substrate 10 in the -Y direction are connected along the Z-axis. Flow path 121B is a flow path that constitutes a portion of the common liquid chamber 100B on the discharge side. When viewed along the Z-axis, it extends through the connecting plate 120 throughout the Z-axis direction and is positioned to overlap with flow path 16B of the pressure chamber substrate 10. Furthermore, when viewed along the Z-axis, the flow path 121B extends along the +Y direction to a position overlapping with the end of the detection chamber 15 in the -Y direction. The portion of the flow path 121B extending along the +Y direction does not penetrate the connecting plate 120 along the Z-axis, but has a concave shape with an opening on the surface facing the +Z direction. Additionally, the connecting plate 120 is provided with a discharge connecting path 122 that connects the detection chamber 15 and the flow path 121B, through which ink from the detection chamber 15 is discharged into the flow path 121B.

[0038] In addition, the connecting plate 120 includes: a connecting path 123 that independently connects each pressure chamber 12 and each nozzle 21; and a recovery path 124 for recovering the ink in the connecting path 123 and the pressure chamber 12 to the outside of the liquid jet head H.

[0039] The connecting passage 123 is defined by a through hole that passes through the connecting plate 120 along the Z-axis direction. Therefore, the end of the connecting passage 123 in the -Z direction is connected to the pressure chamber 12, and the end in the +Z direction is connected to the nozzle 21. Multiple such connecting passages 123 and pressure chambers 12 are independently provided, that is, independently in the X-axis direction.

[0040] The width of the connecting path 123 in the Y-axis direction gradually decreases as it moves towards the +Z direction. That is, the two sides of the connecting path 123 in the Y-axis direction become inclined surfaces that slope towards the Z-axis direction. Specifically, the side of the connecting path 123 in the -Y direction is composed of an inclined surface that slopes towards the -Z direction as it moves towards the -Y direction. Furthermore, the side of the connecting path 123 in the +Y direction is composed of an inclined surface that slopes towards the +Z direction as it moves towards the -Y direction.

[0041] The recycling path 124 is defined by a recess in the connecting plate 120 facing the +Z direction from the -Z direction and connected to the connecting path 123. It should be noted that, in this specification, a "recess" refers to a space that is open on one side of the substrate and not open on the opposite side; that is, a space that does not penetrate the substrate along its thickness but is provided on a portion of its thickness. In this embodiment, the recycling path 124 is open on the surface of the connecting plate 120 facing the -Z direction and not open on the surface facing the +Z direction; that is, it does not penetrate the connecting plate 120 along the Z-axis direction but is provided on a portion of its thickness in the Z-axis direction. Therefore, the recess forming the recycling path 124 does not open on the surface of the connecting plate 120 facing the +Z direction.

[0042] In other words, the recovery path 124 is not defined by the nozzle plate 20 fixed to the surface of the connecting plate 120 in the +Z direction. Multiple such recovery paths 124 are independently provided relative to each pressure chamber 12, i.e., independently in the X-axis direction. Furthermore, the recovery path 124 extends from the connection port with the connecting path 123 in the -Y direction. That is, when viewed along the +Z direction, the absorption chamber 14 and ink supply path 13 constituting the supply path, the pressure chamber 12 and connecting path 123, and the recovery path 124 are arranged side-by-side in the -Y direction.

[0043] The end of the recycling path 124 in the +Y direction is connected to the connecting path 123, and the end in the -Y direction extends to a position overlapping with the end of the detection chamber 15 in the +Y direction when viewed along the Z-axis.

[0044] The width of the recovery path 124 in the X-axis direction can be smaller than, or the same as, the width of the connecting path 123 in the X-axis direction. By setting the width of the recovery path 124 in the X-axis direction to be smaller than that of the connecting path 123, the flow path cross-sectional area of ​​the recovery path 124 can be reduced, and the flow rate of the ink flowing within the recovery path 124 can be increased. This facilitates the removal of air bubbles from the recovery path 124 to the outside. Furthermore, by setting the width of the recovery path 124 in the X-axis direction to be the same as that of the connecting path 123 in the X-axis direction, a step due to the difference in width will not be formed at the connection between the connecting path 123 and the recovery path 124, thereby suppressing poor air bubble removal caused by air bubbles getting stuck at the step.

[0045] It should be noted that the connecting path 123 is defined by the partition wall 11 on both sides in the X-axis direction, and by the nozzle plate 20 in the +Z direction.

[0046] Furthermore, viewed along the +Z direction, the recovery path 124 is positioned overlapping with the pressure chamber 12, and the recovery path 124 connects to the pressure chamber 12 in the overlapping area. That is, the recovery path 124 is provided with an opening on the -Z direction-facing surface of the connecting plate 120, and the pressure chamber 12 extends from the connecting path 123 in the -Y direction. Therefore, the opening of the recovery path 124 on the -Z direction-facing surface of the connecting plate 120 and the portion of the pressure chamber 12 extending from the connecting path 123 in the -Y direction are connected in the Z-axis direction. Thus, by directly connecting the recovery path 124 to the pressure chamber 12, even if bubbles enter the pressure chamber 12 from the connecting path 123, the bubbles in the pressure chamber 12 can be discharged to the recovery path 124. It is worth noting that if the recovery path 124 is not directly connected to the pressure chamber 12 but only connected to the connecting path 123, it is difficult for bubbles entering the pressure chamber 12 to move to the recovery path 124 via the connecting path 123.

[0047] The nozzle plate 20 is a plate-shaped component joined to the surface of the connecting plate 120 opposite to that of the pressure chamber substrate 10, i.e., facing the +Z direction. A plurality of nozzles 21 are formed on the nozzle plate 20, and these nozzles 21 are connected to each pressure chamber 12 via a connecting passage 123. In this embodiment, the plurality of nozzles 21 are arranged side-by-side in a row along the X-axis direction. Such a nozzle plate 20 is preferably made of a silicon substrate or an SOI substrate. It should be noted that the material of the nozzle plate 20 is not limited to this; it can also be made of a glass substrate, various ceramic substrates, metal substrates such as stainless steel substrates, organic materials such as polyimide resin, etc. In this embodiment, the surface of the nozzle 21 opening facing the +Z direction is referred to as the nozzle surface 20a.

[0048] In this configuration, ink in the common liquid chamber 100A is supplied to the nozzle 21 via the absorption chamber 14, ink supply path 13, pressure chamber 12, and connecting path 123. Furthermore, ink not ejected from the nozzle 21 within the pressure chamber 12 and connecting path 123 is recovered back to the common liquid chamber 100B via the recovery path 124, detection chamber 15, and discharge connecting path 122. In other words, in this embodiment, the "independent supply path" that is independently connected to and supplies ink to the nozzle 21 includes the ink supply path 13, pressure chamber 12, and connecting path 123. Similarly, the "independent recovery path" that is independently connected to and recovers ink not ejected from the nozzle 21 includes the connecting path 123, pressure chamber 12, recovery path 124, and detection chamber 15. It should be noted that if the discharge connecting path 122 is provided independently of the detection chamber 15, then the independent recovery path includes the discharge connecting path 122. Additionally, the discharge connecting path 122 may extend to multiple detection chambers 15, i.e., be continuously provided throughout the X-axis direction. It should be noted that in this embodiment, the independent supply path, independent discharge path, and nozzle 21 are collectively referred to as "independent flow path". Furthermore, the flow path shared and connected by multiple independent flow paths is referred to as "common flow path". In this embodiment, common liquid chambers 100A and 100B are provided as common flow paths. Thus, by forming part of the independent flow path rather than the common flow path with the detection chamber 15 and pressure chamber 12, residual vibration of each pressure chamber 12 can be detected independently through the detection chamber 15, and ejection defects of each nozzle 21 can be detected independently. Furthermore, by forming part of the independent recovery path with the detection chamber 15, compared to the case where the detection chamber 15 is formed as part of the independent supply path, the flow path length of the independent supply path can be shortened. Therefore, the flow path length of the independent supply path can be shortened, pressure loss can be reduced, and the occurrence of poor ink supply to the pressure chamber 12 can be suppressed.

[0049] Furthermore, in this embodiment, since the recovery path 124 is connected to the connecting path 123, which is located further in the +Z direction than the pressure chamber 12, air bubbles introduced from the nozzle 21 and entering the connecting path 123, as well as air bubbles entering the connecting path 123 from the ink supply path 13, can be discharged into the recovery path 124 before rising in the pressure chamber 12 due to buoyancy. Therefore, the air bubble discharge performance of the recovery path 124 can be improved.

[0050] On the surface of the pressure chamber substrate 10 facing the -Z direction, as described above, a first piezoelectric element 301, a second piezoelectric element 302, and a third piezoelectric element 303 are stacked via a first vibrating plate 51, a second vibrating plate 52, and a third vibrating plate 53.

[0051] In this embodiment, the first vibrating plate 51, the second vibrating plate 52, and the third vibrating plate 53 have the same layered structure with the same thickness and the same material. Therefore, from now on, without distinguishing between the first vibrating plate 51, the second vibrating plate 52, and the third vibrating plate 53, they will be referred to as vibrating plate 50. Of course, the first vibrating plate 51, the second vibrating plate 52, and the third vibrating plate 53 may also have different layered structures with different film thicknesses, materials, etc.

[0052] The first vibrating plate 51, for example, has an elastic membrane 50a made of silicon oxide and an insulating membrane 50b made of zirconium oxide disposed on the -Z direction-facing surface of the elastic membrane 50a. In this embodiment, the second vibrating plate 52 and the third vibrating plate 53 are disposed continuously with the first vibrating plate 51. That is, the second vibrating plate 52 and the third vibrating plate 53 have the elastic membrane 50a and the insulating membrane 50b. It should be noted that the vibrating plate 50 may be composed only of the elastic membrane 50a, or only of the insulating membrane 50b, or may be composed of other membranes besides the elastic membrane 50a and the insulating membrane 50b. The portion of the vibrating plate 50 disposed on the -Z direction-facing surface of the pressure chamber substrate 10 that covers the opening in the -Z direction-facing surface of the pressure chamber substrate 10 and the portion covering the detection chamber 15 is referred to as the first vibrating plate 51, the portion covering the detection chamber 15 is referred to as the second vibrating plate 52, and the portion covering the absorption chamber 14 is referred to as the third vibrating plate 53. It should be noted that the pressure chamber substrate 10 and a portion of the vibrating plate 50, namely the elastic membrane 50a, can be formed integrally. In this case, the recesses serving as the pressure chamber 12, ink supply path 13, absorption chamber 14, and detection chamber 15 can also be formed by etching the surface of the pressure chamber substrate 10 facing the +Z direction along the -Z direction. In this case, the bottom surface of the recess becomes the elastic membrane 50a. Alternatively, the entire vibrating plate 50 and the pressure chamber substrate 10 can be formed integrally.

[0053] The first piezoelectric element 301, the second piezoelectric element 302, and the third piezoelectric element 303 each have electrodes on their upper surface (facing the -Z direction) and lower surface (facing the +Z direction) of a piezoelectric body made of a piezoelectric material composed of a perovskite composite oxide with the chemical formula ABO3. When a voltage is applied between the upper and lower electrodes, the piezoelectric body, held between the two electrodes, deforms due to the electrostrictive effect. Conversely, if a force is applied externally to deform the piezoelectric body, a voltage is generated between the electrodes due to the piezoelectric effect. In this embodiment, the first piezoelectric element 301, the second piezoelectric element 302, and the third piezoelectric element 303 have roughly the same configuration, but the first piezoelectric element 301 is used as a piezoelectric element that causes the first vibrating plate 51 to vibrate by applying a voltage between the electrodes, and the second piezoelectric element 302 generates pressure by applying vibration to the second vibrating plate 52 from the outside, thereby serving as a piezoelectric element for detecting vibration. Although the third piezoelectric element 303 has the same structure as the other piezoelectric elements, its upper and lower electrodes are not electrically connected; instead, it serves as a mass for absorbing pressure changes in the ink in the absorption chamber 14. Furthermore, in this embodiment, the first piezoelectric element 301, the second piezoelectric element 302, and the third piezoelectric element 303 are formed simultaneously using the same material. This reduces manufacturing costs. Of course, the first piezoelectric element 301, the second piezoelectric element 302, and the third piezoelectric element 303 can also be formed using different materials through different manufacturing processes.

[0054] First, the first piezoelectric element 301 will be described. The first piezoelectric element 301 includes a first lower electrode 61, a first piezoelectric layer 71, and a first upper electrode 81, which are sequentially stacked on the first vibrating plate 51. This first piezoelectric element 301 is also called a piezoelectric actuator, referring to the portion including the first lower electrode 61, the first piezoelectric layer 71, and the first upper electrode 81. Furthermore, the portion in which piezoelectric strain is generated in the first piezoelectric layer 71 when a voltage is applied between the first lower electrode 61 and the first upper electrode 81 is called the first active portion 311. Conversely, the portion in which piezoelectric strain is not generated in the first piezoelectric layer 71 is called the non-active portion. That is, the first active portion 311 refers to the portion of the first piezoelectric layer 71 sandwiched between the first lower electrode 61 and the first upper electrode 81. In other words, the first active portion 311 refers to the portion where the first piezoelectric layer 71, the first lower electrode 61, and the first upper electrode 81 overlap along the Z-axis. In this embodiment, a first active portion 311 is formed in each pressure chamber 12. That is, a plurality of first active portions 311 are formed in the first piezoelectric element 301. The plurality of first active portions 311 are arranged side by side along the X-axis direction. The plurality of first active portions 311 serve as driving elements that cause pressure changes in the ink within the pressure chamber 12. Furthermore, generally, the electrode of one of the first active portions 311 is set as an independent electrode for each first active portion 311, and the electrode of the other is set as a common electrode shared by the plurality of first active portions 311. In this embodiment, the first lower electrode 61 is set as an independent electrode, and the first upper electrode 81 is set as a common electrode. In addition, the portion of the first piezoelectric element 301 that faces the pressure chamber 12 in the Z-axis direction is called a flexible portion, and the outer portion that does not face the pressure chamber 12 in the Z-axis direction is called a non-flexible portion.

[0055] Here, the first lower electrode 61 is divided into individual electrodes for each first active portion 311 by each pressure chamber 12. The first lower electrode 61 is formed with a width narrower than the width of the pressure chamber 12 in the X-axis direction. That is, in the X-axis direction, the end of the first lower electrode 61 is located inside the region opposite to the pressure chamber 12. In addition, the end of the first lower electrode 61 in the -Y direction is positioned outside the pressure chamber 12. At the end of the first lower electrode 61 in the -Y direction, the end positioned outside the pressure chamber 12 is not covered by the first piezoelectric layer 71 and is connected to a first independent lead electrode 91A as a lead-out wiring.

[0056] The first piezoelectric layer 71 is continuously provided in the X-axis direction with a predetermined width in the Y-axis direction. Furthermore, the first piezoelectric layer 71 has a first recess 71a corresponding to each partition wall 11. The width of the first recess 71a in the X-axis direction is the same as or wider than the width of each partition wall 11. In this embodiment, the width of the first recess 71a in the X-axis direction is wider than the width of the partition wall 11. Therefore, since the rigidity of the portions of the vibrating plate 50 corresponding to the two ends of the pressure chamber 12 in the X-axis direction, i.e., the so-called arms of the vibrating plate 50, is suppressed, the displacement efficiency of the first piezoelectric element 301 can be improved. It should be noted that the first recess 71a may be provided through the first piezoelectric layer 71 in the thickness direction, i.e., the Z-axis direction, or it may be provided in the middle of the thickness of the first piezoelectric layer 71 without penetrating through it.

[0057] In other words, the bottom surface of the first recess 71a can completely remove the first piezoelectric layer 71, or a portion of the first piezoelectric layer 71 may remain. In this embodiment, the first recess 71a is provided to penetrate the first piezoelectric layer 71 along the Z-axis direction, and the bottom surface of the first recess 71a is defined by the vibrating plate 50.

[0058] The first upper electrode 81 is continuously disposed across the surface of the first piezoelectric layer 71 facing the -Z direction, forming a common electrode shared by multiple first active portions 311. The first upper electrode 81 is continuously disposed across the X-axis direction with a predetermined width in the Y-axis direction. In addition, the first upper electrode 81 is also disposed on the inner surface of the first recess 71a, that is, on the side surface of the first recess 71a of the first piezoelectric layer 71, and on the vibrating plate 50 which serves as the bottom surface of the first recess 71a. Of course, the first upper electrode 81 may be disposed only on a portion of the inner surface of the first recess 71a, or it may be disposed across the entire surface of the first recess 71a.

[0059] In this first piezoelectric element 301, the two ends of the first active portion 311 in the X-axis direction are defined by the two ends of the first lower electrode 61 in the X-axis direction. Furthermore, the end of the first active portion 311 in the -Y direction is defined by the end of the first upper electrode 81 in the -Y direction, and the end of the first active portion 311 in the +Y direction is defined by the end of the first lower electrode 61 in the +Y direction. It should be noted that the first lower electrode 61 is positioned to overlap with the center of the pressure chamber 12 in the X-axis direction. That is, the first active portion 311 is positioned to overlap with the center of the pressure chamber 12 in the X-axis direction. Similarly, the first active portion 311 is positioned to overlap with the center of the pressure chamber 12 in the Y-axis direction. It should be noted that the center of the pressure chamber 12 in the X-axis direction refers to the intersection of the diagonals of the pressure chamber 12 when viewed from above along the +Z direction, taking into account the opening of the pressure chamber 12 in the -Z direction.

[0060] Additionally, a first independent lead electrode 91A is drawn from the first lower electrode 61 as a lead-out wiring. Furthermore, a first common lead electrode 91B is drawn from the first upper electrode 81 as a lead-out wiring. Although the first independent lead electrode 91A and the first common lead electrode 91B are constructed from the same layer, they are electrically discontinuous. Furthermore, the first independent lead electrode 91A and the first common lead electrode 91B are constructed from a sealing layer (not shown) and a conductive layer disposed on the -Z direction-oriented side of the sealing layer.

[0061] Furthermore, the first common lead electrode 91B includes a first extension portion 93, which is provided in the Y-axis direction across the boundary between the flexible and non-flexible portions on the respective walls of the pressure chamber 12 on both sides. A portion of the first extension portion 93 is provided on the first upper electrode 81, or at both ends of the first upper electrode 81 and the first piezoelectric layer 71 in the Y-axis direction. The first extension portion 93 is continuously provided along the X-axis direction of the plurality of first active portions 311, and is continuous with the first common lead electrode 91B at both ends in the X-axis direction. That is, when viewed from above in the +Z direction, the first common lead electrode 91B with the first extension portion 93 is continuously arranged to surround the periphery of the plurality of first active portions 311. In other words, the first extension portion 93 refers to two portions of the first common lead electrode 91B provided along the X-axis direction.

[0062] Thus, by providing the first extension portion 93, the voltage drop of the first upper electrode 81 in the X-axis direction can be suppressed, and the decrease and unevenness of the ejection characteristics of the ink ejected from each nozzle 21 can be suppressed. In particular, in this embodiment, by providing the first extension portion 93 at each of the two ends of the first active portion 311 in the Y-axis direction, the cross-sectional area along the YZ plane defined by the Y-axis and Z-axis of the first extension portion 93 can be increased, the resistance value can be set relatively small, and the voltage drop can be effectively suppressed. In addition, by providing the first extension portion 93 at a position that overlaps with the boundary between the flexible portion and the non-flexible portion when viewed in the +Z direction, the rigidity of the boundary between the flexible portion and the non-flexible portion can be improved, and the damage of the first piezoelectric layer 71 under stress concentration at the boundary between the flexible portion and the non-flexible portion can be suppressed. Furthermore, by providing the first extension setting portion 93 along the Y-axis at the two ends of the first active portion 311 where the deformation amount is relatively small, rather than at the central portion where the deformation amount is relatively large, it is possible to suppress the first extension setting portion 93 from hindering the deformation of the first active portion 311, and to suppress the significant decrease in the deformation amount of the first piezoelectric element 301.

[0063] Furthermore, a flexible wiring substrate, i.e., a flexible substrate 110, is connected to the end opposite to the end connected to the first independent lead electrode 91A and the first common lead electrode 91B and the end connected to the first piezoelectric element 301. The flexible substrate 110 is electrically connected to the control unit 4, and the flexible substrate 110 exchanges signals that drive the first piezoelectric element 301 and detection signals corresponding to residual vibrations generated in the second piezoelectric element 302 between the flexible substrate 110 and the control unit 4 via the control circuit 111. That is, the control circuit 111 has multiple switching elements that select whether to supply the respective drive signals used to drive the first piezoelectric element 301 to each of the first piezoelectric element 301. That is, the flexible substrate 110 in this embodiment is a COF (Chip On Film). It should be noted that the control circuit 111 may not be provided on the flexible substrate 110. That is, the flexible substrate 110 may also be an FFC (Flexible Flat Cable), FPC (Flexible Printed Circuits), etc.

[0064] The third vibrating plate 53 covers the portion of the pressure chamber substrate 10 that corresponds to the absorption chamber 14 in the opening facing the -Z direction. As described above, the third vibrating plate 53 is formed continuously with the first vibrating plate 51. That is, the third vibrating plate 53 has an elastic membrane 50a and an insulating membrane 50b. The third vibrating plate 53 deforms under the pressure of the ink in the absorption chamber 14, and absorbs the pressure variation of the ink in the absorption chamber 14.

[0065] Furthermore, a third piezoelectric element 303 is stacked on the surface of the third vibrating plate 53 facing the -Z direction. The third piezoelectric element 303, when viewed along the Z-axis, is positioned overlapping the absorption chamber 14. Like the first piezoelectric element 301, the third piezoelectric element 303 has a third lower electrode 63, a third piezoelectric layer 73, and a third upper electrode 83 sequentially stacked on the third vibrating plate 53. The third lower electrode 63, the third piezoelectric layer 73, and the third upper electrode 83 are made of the same material as the first lower electrode 61, the first piezoelectric layer 71, and the first upper electrode 81 of the first piezoelectric element 301. It should be noted that the third piezoelectric element 303 differs from the first piezoelectric element 301, and the third lower electrode 63 is continuously arranged throughout the X-axis direction. Of course, the third lower electrode 63 can also be divided into multiple parts relative to one absorption chamber 14. Furthermore, the third piezoelectric element 303 is not necessarily required and may be omitted.

[0066] The second vibrating plate 52 covers the portion of the pressure chamber substrate 10 that corresponds to the detection chamber 15 in the opening facing the -Z direction. The second vibrating plate 52 is continuously formed with the first vibrating plate 51. That is, the second vibrating plate 52 has an elastic membrane 50a and an insulating membrane 50b. Of course, each layer of the second vibrating plate 52 can be formed simultaneously with the first vibrating plate 51 or formed independently. The second vibrating plate 52 can deform according to the pressure change of the ink in the detection chamber 15. Multiple second vibrating plates 52 correspond to multiple detection chambers 15 and deform independently.

[0067] Furthermore, a second piezoelectric element 302 is stacked on the -Z direction-facing surface of the second vibrating plate 52. The second piezoelectric element 302 is positioned to overlap with the detection chamber 15 when viewed along the Z-axis. Like the first piezoelectric element 301, the second piezoelectric element 302 includes a second lower electrode 62, a second piezoelectric layer 72, and a second upper electrode 82, which are sequentially stacked on the second vibrating plate 52. The portion of the second piezoelectric layer 72 that generates piezoelectric strain when a voltage is applied between the second lower electrode 62 and the second upper electrode 82 is called the second active portion 312. Conversely, the portion of the second piezoelectric layer 72 that does not generate piezoelectric strain is called the non-active portion. That is, the second active portion 312 refers to the portion of the second piezoelectric layer 72 sandwiched between the second lower electrode 62 and the second upper electrode 82. In other words, the second active portion 312 refers to the portion where the second piezoelectric layer 72, the second lower electrode 62, and the second upper electrode 82 overlap along the Z-axis. In this embodiment, a second active portion 312 is formed in each detection chamber 15. That is, a plurality of second active portions 312 are formed in the second piezoelectric element 302. These plurality of second active portions 312 serve as detection elements for detecting pressure changes within the detection chamber 15. Furthermore, generally, the electrode of one of the second active portions 312 is configured as an independent electrode for each second active portion 312, and the electrode of the other is configured as a common electrode shared by the plurality of second active portions 312. In this embodiment, the second lower electrode 62 is configured as an independent electrode, and the second upper electrode 82 is configured as a common electrode. In addition, the portion of the second piezoelectric element 302 that faces the detection chamber 15 in the Z-axis direction is called a flexible portion, and the portion on the outside that does not face the detection chamber 15 in the Z-axis direction is called a non-flexible portion.

[0068] Here, the second lower electrode 62 is divided into individual electrodes for each second active portion 312 by each detection chamber 15. The second lower electrode 62 is formed with a width narrower than the width of the detection chamber 15 in the X-axis direction. That is, in the X-axis direction, the end of the second lower electrode 62 is located inside the region opposite to the detection chamber 15. In addition, the end of the second lower electrode 62 in the +Y direction is positioned outside the detection chamber 15. At the end of the second lower electrode 62 in the +Y direction, the end positioned outside the detection chamber 15 is not covered by the second piezoelectric layer 72 and is connected to a second independent lead electrode 92A as a lead wire.

[0069] The second piezoelectric layer 72 is continuously provided in the X-axis direction with a predetermined width in the Y-axis direction. Furthermore, the second piezoelectric layer 72 has a second recess 72a corresponding to each partition wall 11. The width of the second recess 72a in the X-axis direction is the same as or wider than the width of each partition wall 11. In this embodiment, the width of the second recess 72a in the X-axis direction is wider than the width of the partition wall 11. Therefore, since the rigidity of the portions of the vibrating plate 50 corresponding to the two ends of the detection chamber 15 in the X-axis direction, i.e., the so-called arms of the vibrating plate 50, is suppressed, the displacement efficiency of the second piezoelectric element 302 can be improved. It should be noted that the second recess 72a can be provided through the second piezoelectric layer 72 in the thickness direction, i.e., the Z-axis direction, just like the first recess 71a, or it can be provided at the midpoint of the thickness of the second piezoelectric layer 72 without penetrating through it.

[0070] The second upper electrode 82 is continuously disposed across the surface of the second piezoelectric layer 72 facing the -Z direction, forming a common electrode shared by multiple second active portions 312. The second upper electrode 82 is continuously disposed across the X-axis direction with a predetermined width in the Y-axis direction. In addition, the second upper electrode 82 is also disposed on the inner surface of the second recess 72a, that is, on the side surface of the second recess 72a of the second piezoelectric layer 72, and on the vibrating plate 50 which serves as the bottom surface of the second recess 72a. Of course, the second upper electrode 82 may be disposed only on a portion of the inner surface of the second recess 72a, or it may be disposed across the entire surface of the second recess 72a.

[0071] It should be noted that the width of the second piezoelectric layer 72 and the second upper electrode 82 in the X-axis direction can be the same as or different from the width of the first piezoelectric layer 71 and the first upper electrode 81 in the X-axis direction.

[0072] In this second piezoelectric element 302, the two ends of the second active portion 312 in the X-axis direction are defined by the two ends of the second lower electrode 62 in the X-axis direction. Furthermore, the end of the second active portion 312 in the -Y direction is defined by the end of the second lower electrode 62 in the -Y direction, and the end of the second active portion 312 in the +Y direction is defined by the end of the second upper electrode 82 in the +Y direction. It should be noted that the second lower electrode 62 is positioned to overlap with the center of the detection chamber 15 in the X-axis direction. That is, the second active portion 312 is positioned to overlap with the center of the detection chamber 15 in the X-axis direction. Similarly, the second active portion 312 is positioned to overlap with the center of the detection chamber 15 in the Y-axis direction. It should be noted that the center of the detection chamber 15 in the X-axis direction refers to the intersection of the diagonals of the detection chamber 15 when viewed from above along the +Z direction, taking into account the opening of the detection chamber 15 in the -Z direction.

[0073] A second independent lead electrode 92A is drawn from the second lower electrode 62 as a lead-out wiring. Additionally, a second common lead electrode 92B is drawn from the second upper electrode 82 as a lead-out wiring. The second independent lead electrode 92A and the second common lead electrode 92B are formed in the same layer, but are electrically discontinuous. It should be noted that in this embodiment, the first independent lead electrode 91A, the first common lead electrode 91B, the second independent lead electrode 92A, and the second common lead electrode 92B are formed on the same layer. Therefore, the first independent lead electrode 91A, the first common lead electrode 91B, the second independent lead electrode 92A, and the second common lead electrode 92B can be formed simultaneously, and costs can be reduced.

[0074] Furthermore, the second common lead electrode 92B includes a second extension portion 94, which is provided in the Y-axis direction across the boundary between the flexible and non-flexible portions on the respective walls of both sides of the detection chamber 15. A portion of the second extension portion 94 is provided above the second upper electrode 82, or at both ends of the second upper electrode 82 and the second piezoelectric layer 72 in the Y-axis direction. The second extension portion 94 is continuously provided throughout the X-axis direction of the plurality of second active portions 312, and is continuous with the second common lead electrode 92B at both ends in the X-axis direction. That is, when viewed from above in the +Z direction, the second common lead electrode 92B with the second extension portion 94 is continuously arranged to surround the periphery of the plurality of second active portions 312. In other words, the second extension portion 94 refers to the two portions of the second common lead electrode 92B provided along the X-axis direction.

[0075] Thus, by providing the second extension portion 94, the voltage drop of the second upper electrode 82 in the X-axis direction can be suppressed, and the detection efficiency of pressure variation of ink in the detection chamber 15 of the second active portion 312 can be improved. Furthermore, by positioning the second extension portion 94 at a position overlapping the boundary between the flexible and non-flexible portions when viewed along the +Z direction, the rigidity of the boundary between the flexible and non-flexible portions can be improved, and damage to the second piezoelectric layer 72 under stress concentration at the boundary between the flexible and non-flexible portions can be suppressed. Additionally, by positioning the second extension portion 94 along the Y-axis at the two ends of the second active portion 312 where the deformation is relatively small, rather than at the central portion where the deformation is relatively large, the obstruction of the deformation of the second active portion 312 by the second extension portion 94 can be suppressed, and the significant decrease in the deformation of the second piezoelectric element 302 can be suppressed.

[0076] Furthermore, the end opposite to the end connected to the second independent lead electrode 92A and the second common lead electrode 92B and the second piezoelectric element 302 is connected to the flexible substrate 110.

[0077] Here, if the pressure of the ink in the pressure chamber 12 is changed by the first piezoelectric element 301, causing ink droplets to be ejected from the nozzle 21, the pressure change in the pressure chamber 12 will remain for a predetermined period after the ink droplets are ejected. This is called residual vibration. Since the pressure change of the ink in the pressure chamber 12 also propagates to the ink in the detection chamber 15 via the recovery path 124, the second piezoelectric element 302 detects the residual vibration in the detection chamber 15. That is, the second piezoelectric element 302 detects the residual vibration as a voltage signal by the starting voltage generated when the residual vibration of the ink in the detection chamber 15 changes. Furthermore, the control circuit 111 extracts information such as the state of the residual vibration, such as the period and amplitude of the residual vibration, from the voltage signal generated in the second piezoelectric element 302 and outputs it to the control unit 4. The control unit 4 detects poor ink droplet ejection based on the information such as the period and amplitude of the residual vibration.

[0078] Here, as Figures 4-6As shown, in a top-view observation along the +Z direction, the width W1 of the second active portion 312 in the X-axis direction is greater than the width W3 of the first active portion 311 in the X-axis direction. In this embodiment, the end of the second active portion 312 in the X-axis direction is defined by the second lower electrode 62, and the end of the first active portion 311 in the X-axis direction is defined by the first lower electrode 61. Therefore, in a top-view observation along the +Z direction, the width W1 of the second active portion 312 in the X-axis direction is equal to the width W1 of the second lower electrode 62 in the X-axis direction, and the width W3 of the first active portion 311 in the X-axis direction is equal to the width W3 of the first lower electrode 61 in the X-axis direction. That is, the width W1 of the second lower electrode 62 in the X-axis direction is greater than the width W3 of the first lower electrode 61 in the X-axis direction.

[0079] In addition, such as Figure 4 , Figure 7 as well as Figure 8 As shown, in a top-down view along the +Z direction, the length L1 of the second active part 312 in the Y-axis direction is less than the length L3 of the second active part 312 in the Y-axis direction.

[0080] Thus, by relatively increasing the width W1 of the second active portion 312 in the X-axis direction, the amount of strain in the second active portion 312 is increased. This allows the output voltage due to pressure fluctuations within the detection chamber 15 to be increased, thereby improving the detection accuracy of pressure fluctuations within the detection chamber 15. Furthermore, by relatively reducing the width W3 of the first active portion 311 in the X-axis direction, crosstalk between adjacent first active portions 311 along the X-axis direction can be suppressed. Specifically, if the width W3 of the first active portion 311 in the X-axis direction is reduced, the distance d1 between adjacent first active portions 311 along the X-axis direction increases. Therefore, since the vibration of one of the two adjacent first active portions 311 is attenuated before being transmitted to the other, the influence of the vibration of one first active portion 311 on the other, i.e., crosstalk, can be suppressed. Here, the second active part 312 is strained primarily due to residual vibration generated within the detection chamber 15 by the driving of the first active part 311. Therefore, since the strain of the second active part 312 is smaller than that of the first active part 311, crosstalk is unlikely to occur between two adjacent second active parts 312 along the X-axis direction. Even if the distance d2 between adjacent second active parts 312 along the X-axis direction is reduced, problems caused by crosstalk are unlikely to arise. Therefore, by making the width W1 of the second active part 312 in the X-axis direction greater than the width W3 of the first active part 311 in the X-axis direction, the detection accuracy of the residual vibration of the second active part 312 can be improved, and crosstalk of the first active part 311 can be suppressed.

[0081] Furthermore, when the widths of the second active part 312 in the X-axis direction are set to W1, the detection chamber 15 in the X-axis direction to W2, the first active part 311 in the X-axis direction to W3, and the pressure chamber 12 in the X-axis direction to W4, the relationship W1 / W2 > W3 / W4 is satisfied. In this embodiment, since the widths W2 of the detection chamber 15 and W4 of the pressure chamber 12 are the same, the relationship W1 / W2 > W3 / W4 is satisfied by making the width W1 of the second active part 312 greater than the width W3 of the first active part 311. By defining the relationship between the width W1 of the second active part 312, the width W2 of the detection chamber 15, the width W3 of the first active part 311, and the width W4 of the pressure chamber 12, the second active part 312 can be configured with the largest possible width relative to the detection chamber 15, which has a finite width W2 in the X-axis direction, and the amount of strain of the second active part 312 can be increased to improve the detection accuracy of the residual vibration of the second active part 312.

[0082] Furthermore, when viewed from above in the +Z direction, if the area of ​​the second active part 312 is set to S1, the area of ​​the detection chamber 15 is set to S2, the area of ​​the first active part 311 is set to S3, and the area of ​​the pressure chamber 12 is set to S4, the relationship S1 / S2 > S3 / S4 is satisfied. By defining the relationship between the area S1 of the second active part 312, the area S2 of the detection chamber 15, the area S3 of the first active part 311, and the area S4 of the pressure chamber 12 in this way, the second active part 312 can be arranged with the largest possible area relative to the detection chamber 15, which has a limited area, and the amount of strain of the second active part 312 can be increased to improve the detection accuracy of the residual vibration of the second active part 312. Furthermore, since the area S3 of the first active part 311 can be set with a relatively small area relative to the pressure chamber 12, the deformation of the first active part 311 can be reduced, and the vibration of one first active part 311 can be suppressed from affecting the other first active part 311, i.e., crosstalk, in two adjacent first active parts 311.

[0083] In addition, such as Figure 4As shown, preferably, the distance d1 between two adjacent first active portions 311 along the X-axis is greater than the width W3 of the first active portion 311 along the X-axis. By making the distance d1 between two adjacent first active portions 311 along the X-axis greater than the width W3 of the first active portion 311 along the X-axis, crosstalk generated between adjacent first active portions 311 along the X-axis can be reduced. It should be noted that preferably, the distance d1 between two adjacent first active portions 311 along the X-axis is greater than the width W1 of the second active portion 312 along the X-axis. Therefore, the distance d1 between two adjacent first active portions 311 along the X-axis can be increased, and crosstalk generated between adjacent first active portions 311 along the X-axis can be further reduced.

[0084] In addition, such as Figure 4 As shown, preferably, the width W1 of the second active portion 312 in the X-axis direction is greater than the distance d2 between two adjacent second active portions 312 in the X-axis direction. By making the width W1 of the second active portion 312 in the X-axis direction greater than the distance d2 between two second active portions 312 in the X-axis direction, the width W1 of the second active portion 312 can be relatively increased, and the detection accuracy of the residual vibration of the second active portion 312 can be improved. It should be noted that the distances d1 and d2 are the minimum dimensions of the intervals along the X-axis direction when viewed from above in the +Z direction.

[0085] Furthermore, in this embodiment, as described above, the length L2 of the detection chamber 15 in the Y-axis direction is less than the length L4 of the pressure chamber 12 in the Y-axis direction. In this embodiment, since the width W2 of the detection chamber 15 in the X-axis direction is less than the width W4 of the pressure chamber 12 in the X-axis direction, the area of ​​the detection chamber 15 is smaller than the area of ​​the pressure chamber 12 when viewed from above along the +Z direction. In this embodiment, since both the pressure chamber 12 and the detection chamber 15 are provided to penetrate the pressure chamber substrate 10 throughout the Z-axis direction, their heights in the Z-axis direction are the same. Therefore, the volume of the detection chamber 15 is smaller than the volume of the pressure chamber 12. By reducing the size of the detection chamber 15 in this way, the plasticity of the detection chamber 15 is reduced, and the overall plasticity of the independent flow path is reduced, thus enabling high-frequency driving of the first active part 311. Furthermore, if the plasticity of the detection chamber 15 is reduced, the second vibrating plate 52 corresponding to the detection chamber 15 will become difficult to strain. However, by making the width W1 of the second active part 312 in the X-axis direction greater than the width W3 of the first active part 311, the strain of the second active part 312 is increased, thereby improving the detection accuracy of the second active part 312 in detecting residual vibrations within the detection chamber 15. In other words, if the second vibrating plate 52 corresponding to the detection chamber 15 is difficult to strain, the deformation of the second active part 312 will be smaller, and the voltage output from the second active part 312 will be smaller. However, by increasing the width W1 of the second active part 312, the second active part 312 can be strained relatively larger and output a larger voltage, thus improving the detection accuracy. It is worth mentioning that, instead of making the length L1 of the detection chamber 15 in the Y-axis direction smaller than the length L4 of the pressure chamber 12 in the Y-axis direction, for example, even if one of the second vibration plate 52 corresponding to the detection chamber 15 is thicker than the first vibration plate 51 corresponding to the pressure chamber 12, is made of a harder material, or has a higher Young's modulus, the same effect can be obtained.

[0086] Furthermore, the pressure chamber 12 and the detection chamber 15 are disposed on the same pressure chamber substrate 10, which is located between the pressure chamber 12 and the detection chamber 15, and has a partition wall 17 that divides the sides of the pressure chamber 12 and the detection chamber 15 in the Y-axis direction. By dividing the detection chamber 15 and the pressure chamber 12 using the partition wall 17, it is difficult for the deformation of the second vibrating plate 52 corresponding to the second active part 312 to absorb the pressure generated in the pressure chamber 12 due to the first active part 311, and the first active part 311 can be driven at high frequency to perform high-frequency ink ejection. It is worth mentioning that if the pressure chamber 12 and the detection chamber 15 are not separated by the partition wall 17, that is, if the first active part 311 and the second active part 312 are provided in a common space that is continuous with the pressure chamber 12 and the detection chamber 15, the pressure generated in the pressure chamber 12 due to the first active part 311 can be easily absorbed by the deformation of the second vibration plate 52 corresponding to the second active part 312, and the first active part 311 cannot be driven at high frequency.

[0087] A protective substrate 30, approximately the same size as the pressure chamber substrate 10, is bonded to the surface of the pressure chamber substrate 10 facing the -Z direction. The protective substrate 30 has receiving portions 31A to 31C, which are spaces that respectively protect the first piezoelectric element 301, the second piezoelectric element 302, and the third piezoelectric element 303. The receiving portions 31A to 31C have concave shapes with openings on the surface of the protective substrate 30 facing the +Z direction. A plurality of first piezoelectric elements 301 are received in receiving portion 31A. A plurality of second piezoelectric elements 302 are received in receiving portion 31B. A single third piezoelectric element 303 is received in receiving portion 31C. Furthermore, the protective substrate 30 has an opening 32 extending along the Z-axis between the two receiving portions 31A and 31B arranged side-by-side along the Y-axis. The ends of the first independent lead electrode 91A and the first common lead electrode 91B extending from the electrodes of the first piezoelectric element 301, and the second independent lead electrode 92A and the second common lead electrode 92B extending from the electrodes of the second piezoelectric element 302, extend outwards into the opening 32. Furthermore, the first independent lead electrode 91A, the first common lead electrode 91B, the second independent lead electrode 92A, the second common lead electrode 92B, and the flexible substrate 110 are electrically connected within the opening 32. This opening 32, when viewed along the Z-axis, is positioned to overlap with the recovery path 124.

[0088] In other words, the flexible substrate 110 is joined to various lead electrodes 91A, 91B, 92A, 92B, etc., extending from the first piezoelectric element 301 and the second piezoelectric element 302 on the vibrating plate 50 at a position where it overlaps with the recovery path 124 when viewed along the -Z direction of the vibrating plate 50. In other words, the flexible substrate 110 is connected to the vibrating plate 50 between the pressure chamber 12 and the detection chamber 15 in the Y-axis direction. In other words, the flexible substrate 110 is connected to the vibrating plate 50 at a position where it overlaps with the flow path where the pressure chamber substrate 10 is not provided, when viewed along the -Z direction. Here, the vibrating plate 50 is prone to deformation due to the pressure applied to the pressure chamber 12 and the deformation due to pressure variations within the detection chamber 15. Therefore, for example, if a recovery path is provided on the pressure chamber substrate 10, the vibrating plate 50 on the recovery path is thin, and the flexible substrate 110 is connected to the vibrating plate 50 on the recovery path, making the vibrating plate 50 prone to cracking due to stress when connecting the flexible substrate 110. In this embodiment, the recovery path 124 is provided on the connecting plate 120, and the flexible substrate 110 is connected to the vibrating plate 50 at a position that overlaps with the flow path where the pressure chamber substrate 10 is not provided when viewed along the -Z direction. Therefore, the area of ​​the vibrating plate 50 to which the flexible substrate 110 is connected is supported by the pressure chamber substrate 10. Thus, cracking of the vibrating plate 50 due to stress when the flexible substrate 110 is connected to the vibrating plate 50 can be suppressed.

[0089] Such a protective substrate 30 is preferably made of silicon substrate or SOI substrate. It should be noted that the material of the protective substrate 30 is not limited to this, and can also be made of glass substrate, various ceramic substrates, stainless steel substrates, and other metal substrates.

[0090] Additionally, the protective substrate 30 has a flow path 33A that forms part of the common liquid chamber 100A on the supply side and a flow path 33B that forms part of the common liquid chamber 100B on the discharge side. Flow paths 33A and 33B are provided through the protective substrate 30 along the Z-axis direction. Flow path 33A is located in the +Y direction of the receiving portion 31C, and flow path 33B is located in the -Y direction of the receiving portion 31B.

[0091] The housing 40 is located in the -Z direction of the protective substrate 30. The housing 40 has a flow path 41A that forms part of a common liquid chamber 100A on the supply side and a flow path 41B that forms part of a common liquid chamber 100B on the discharge side. Flow path 41A is positioned to overlap with and communicate with flow path 33A of the protective substrate 30 when viewed along the Z-axis. Similarly, flow path 41B is positioned to overlap with and communicate with flow path 33B of the protective substrate 30 when viewed along the Z-axis. Flow paths 41A and 41B have concave shapes that open onto the surface of the housing 40 facing the +Z direction. The housing 40 also includes a supply port 42 for supplying ink to flow path 41A and a discharge port 43 for discharging ink from flow path 41B to the outside. Such a housing 40 may be made of, for example, metal or resin.

[0092] In this embodiment, the common liquid chamber 100A on the supply side is constructed via a flow path 41A provided in the housing 40, a flow path 33A provided in the protective substrate 30, a flow path 16A provided in the pressure chamber substrate 10, and a flow path 121A provided in the connecting plate 120. Similarly, the common liquid chamber 100B on the discharge side is constructed via a flow path 41B provided in the housing 40, a flow path 33B provided in the protective substrate 30, a flow path 16B provided in the pressure chamber substrate 10, and a flow path 121B provided in the connecting plate 120. Ink from a liquid storage section (not shown) is supplied to the common liquid chamber 100A on the supply side via the supply port 42. The ink in the common liquid chamber 100A on the supply side flows to the common liquid chamber 100B on the discharge side via the absorption chamber 14, the ink supply path 13, the pressure chamber 12, the recovery path 124, and the detection chamber 15. In addition, the ink in the common liquid chamber 100B on the discharge side is discharged from the discharge port 43 to the outside of the liquid jet head H.

[0093] Additionally, the housing 40 has a through hole 44 communicating with the opening 32 of the protective substrate 30. The through hole 44 extends through the housing 40 in the Z-axis direction. Furthermore, the flexible substrate 110 of the pressure chamber substrate 10, which is connected to the first piezoelectric element 301 and the second piezoelectric element 302 on the vibrating plate 50, is led out to the Z-direction facing side of the housing 40 through the opening 32 of the protective substrate 30 and the through hole 44 of the housing 40.

[0094] Furthermore, a supply-side malleable substrate 130A and a discharge-side malleable substrate 130B are provided on the surfaces of the openings of the flow paths 121A and 121B of the connecting plate 120 facing the +Z direction. In this embodiment, the supply-side malleable substrate 130A and the discharge-side malleable substrate 130B have the same configuration. Therefore, the supply-side malleable substrate 130A will be described below, but the discharge-side malleable substrate 130B also has the same configuration.

[0095] In this embodiment, the malleable substrate 130A includes: a sealing film 131, which is made of a flexible thin film; and a fixing substrate 132, which is made of a rigid material such as metal. The region of the fixing substrate 132 opposite to the common liquid chamber 100A becomes an opening 133 that is completely removed in the thickness direction, and the surface of the common liquid chamber 100A in the +Z direction becomes a malleable portion 134 defined only by the sealing film 131. By deforming through such a malleable portion 134, pressure fluctuations of the ink within the common liquid chamber 100A can be absorbed, and unevenness in the ejection characteristics such as the flight speed and weight of the ink droplets ejected from the nozzle 21 can be suppressed.

[0096] Implementation Method 2

[0097] Figure 9 This is a top view of the first piezoelectric element 301, the second piezoelectric element 302, and the pressure chamber substrate 10 according to Embodiment 2 of the present invention, viewed along the +Z direction.

[0098] like Figure 9 As shown, the length L1 of the second active portion 312 of the second piezoelectric element 302 in the Y-axis direction is the same as the length L3 of the first active portion 311 of the first piezoelectric element 301 in the Y-axis direction.

[0099] In addition, similar to Embodiment 1 described above, the width W1 of the second active portion 312 in the X-axis direction is greater than the width W3 of the first active portion 311 in the X-axis direction.

[0100] Therefore, when viewed from above along the +Z direction, the area of ​​the second active part 312, that is, the area S1 defined by the width W1 and length L1 in the X-axis direction, is greater than the area of ​​the first active part 311, that is, the area S3 defined by the width W3 and length L3 in the X-axis direction.

[0101] By making the area S1 of the second active part 312 larger than the area S3 of the first active part 311, the area S1 of the second active part 312 can be relatively increased, thus increasing the amount of strain. This also increases the voltage output from the second active part 312 and improves the detection accuracy of the residual vibration of the second active part 312. Furthermore, by reducing the area S3 of the first active part 311, the deformation of the first active part 311 can be reduced, and crosstalk (i.e., the vibration of one first active part 311 affecting the other) can be suppressed between two adjacent first active parts 311. It should be noted that since the second active part 312 strains mainly due to pressure changes within the detection chamber 15 caused by the driving of the first active part 311, i.e., residual vibration, the amount of strain is smaller compared to the first active part 311. Therefore, even if the area S1 of the second active part 312 is increased, crosstalk is difficult to generate between two second active parts 312 that are adjacent to each other along the X-axis.

[0102] Furthermore, by making the area S1 of the second active part 312 larger than the area S3 of the first active part 311, as described above, the ratio of the area S1 of the second active part 312 to the area S2 of the detection chamber 15 and the ratio of the area S3 of the first active part 311 to the area S4 of the pressure chamber 12 easily satisfy the relationship S1 / S2 > S3 / S4. Therefore, relative to the detection chamber 15 which has a limited area, the second active part 312 can be provided with the largest possible area, thereby increasing the amount of strain of the second active part 312 and improving the detection accuracy of the residual vibration of the second active part 312.

[0103] Furthermore, similarly to Embodiment 1 described above, in this embodiment, since the width W1 of the second active portion 312 is greater than the width W3 of the first active portion 311, and thus the area S1 is greater than the area S2, crosstalk between adjacent first active portions 311 along the X-axis can be suppressed by relatively reducing the width W3 of the first active portion 311 in the X-axis direction. In other words, if the width W3 of the first active portion 311 in the X-axis direction is reduced, the distance d1 between adjacent first active portions 311 along the X-axis direction increases. Therefore, in two adjacent first active portions 311, since the vibration of one first active portion 311 attenuates before being transmitted to the other, crosstalk, caused by the vibration of one first active portion 311, can be suppressed. Here, the second active portion 312 mainly strains due to residual vibration generated within the detection chamber 15 by the driving of the first active portion 311. Therefore, since the strain of the second active portion 312 is smaller than that of the first active portion 311, crosstalk is unlikely to occur between two adjacent second active portions 312 along the X-axis direction. Even if the distance d2 between adjacent second active portions 312 along the X-axis direction is reduced, problems caused by crosstalk are unlikely to occur. Therefore, by making the width W1 of the second active portion 312 in the X-axis direction greater than the width W3 of the first active portion 311 in the X-axis direction, the detection accuracy of the residual vibration of the second active portion 312 can be improved and the crosstalk of the first active portion 311 can be suppressed.

[0104] Furthermore, in this embodiment, similar to Embodiment 1 described above, the widths W1 of the second active part 312 in the X-axis direction, W2 of the detection chamber 15 in the X-axis direction, W3 of the first active part 311 in the X-axis direction, and W4 of the pressure chamber 12 in the X-axis direction are such that W1 / W2 > W3 / W4. In this embodiment, similar to Embodiment 1 described above, the widths W2 of the detection chamber 15 and W4 of the pressure chamber 12 are the same. Therefore, by making the width W1 of the second active part 312 greater than the width W3 of the first active part 311, the relationship W1 / W2 > W3 / W4 is satisfied. By defining the relationship between the width W1 of the second active part 312, the width W2 of the detection chamber 15, the width W3 of the first active part 311, and the width W4 of the pressure chamber 12, the second active part 312 can be configured with the largest possible width relative to the detection chamber 15, which has a finite width W2 in the X-axis direction, and the amount of strain of the second active part 312 can be increased to improve the detection accuracy of the residual vibration of the second active part 312.

[0105] Furthermore, similarly to Embodiment 1 described above, in this embodiment, it is preferable that the distance d1 between two adjacent first active portions 311 along the X-axis is greater than the width W3 of the first active portions 311 along the X-axis. By making the distance d1 between two adjacent first active portions 311 along the X-axis greater than the width W3 of the first active portions 311 along the X-axis, crosstalk generated between adjacent first active portions 311 along the X-axis can be reduced. It should be noted that it is preferable that the distance d1 between two adjacent first active portions 311 along the X-axis is greater than the width W1 of the second active portion 312 along the X-axis. As a result, the distance d1 between two adjacent first active portions 311 along the X-axis can be increased, and crosstalk generated between adjacent first active portions 311 along the X-axis can be further reduced.

[0106] Furthermore, similarly to Embodiment 1 described above, in this embodiment, it is preferable that the width W1 of the second active portion 312 in the X-axis direction is greater than the distance d2 between two adjacent second active portions 312 in the X-axis direction. By making the width W1 of the second active portion 312 in the X-axis direction greater than the distance d2 between two second active portions 312 in the X-axis direction, the width W1 of the second active portion 312 can be relatively increased, and the detection accuracy of the residual vibration of the second active portion 312 can be improved. It should be noted that the distances d1 and d2 are the minimum dimensions of the intervals along the X-axis direction when viewed from above in the +Z direction.

[0107] Furthermore, in this embodiment, similar to Embodiment 1 described above, the length L2 of the detection chamber 15 in the Y-axis direction is less than the length L4 of the pressure chamber 12 in the Y-axis direction. In this embodiment, since the width W2 of the detection chamber 15 in the X-axis direction is less than the width W4 of the pressure chamber 12 in the X-axis direction, the area of ​​the detection chamber 15 is smaller than the area of ​​the pressure chamber 12 when viewed from above along the +Z direction. In this embodiment, since both the pressure chamber 12 and the detection chamber 15 are provided to penetrate the pressure chamber substrate 10 throughout the Z-axis direction, their heights in the Z-axis direction are the same. Therefore, the volume of the detection chamber 15 is smaller than the volume of the pressure chamber 12. By reducing the size of the detection chamber 15 in this way, the plasticity of the detection chamber 15 is reduced, thereby reducing the overall plasticity of the independent flow path, and thus enabling high-frequency driving of the first active part 311. Furthermore, if the plasticity of the detection chamber 15 is reduced, the second vibrating plate 52 corresponding to the detection chamber 15 will become difficult to strain. However, by making the width W1 of the second active part 312 in the X-axis direction greater than the width W3 of the first active part 311, the strain of the second active part 312 is increased, thereby improving the detection accuracy of the second active part 312 in detecting residual vibrations within the detection chamber 15. In other words, if the second vibrating plate 52 corresponding to the detection chamber 15 is difficult to strain, the deformation of the second active part 312 will be smaller, and the voltage output from the second active part 312 will be smaller. However, by increasing the width W1 of the second active part 312, the second active part 312 can be strained relatively larger and output a larger voltage, thus improving the detection accuracy. It is worth mentioning that, instead of making the length L1 of the detection chamber 15 in the Y-axis direction smaller than the length L4 of the pressure chamber 12 in the Y-axis direction, for example, even if one of the second vibration plate 52 corresponding to the detection chamber 15 is thicker than the first vibration plate 51 corresponding to the pressure chamber 12, is made of a harder material, or has a higher Young's modulus, the same effect can be obtained.

[0108] Furthermore, in this embodiment, similar to Embodiment 1 described above, the pressure chamber 12 and the detection chamber 15 are disposed on the same pressure chamber substrate 10, which is located between the pressure chamber 12 and the detection chamber 15, and has a partition wall 17 that defines the sides of the pressure chamber 12 and the detection chamber 15 in the Y-axis direction. By utilizing the partition wall 17 (see reference...) Figure 3The partition wall 17 divides the detection chamber 15 and the pressure chamber 12, making it difficult for the deformation of the second vibrating plate 52 corresponding to the second active part 312 to absorb the pressure generated in the pressure chamber 12 due to the first active part 311. This makes it possible to drive the first active part 311 at high frequency and eject ink at high frequency. It is worth mentioning that if the pressure chamber 12 and the detection chamber 15 are not divided by the partition wall 17, that is, if the first active part 311 and the second active part 312 are provided in a continuous common space with the pressure chamber 12 and the detection chamber 15, it is easy for the deformation of the second vibrating plate 52 corresponding to the second active part 312 to absorb the pressure generated in the pressure chamber 12 due to the first active part 311, making it impossible to drive the first active part 311 at high frequency.

[0109] It should be noted that, as in Embodiment 1 described above, even if the length L1 of the second active part 312 in the Y-axis direction is shorter than the length L3 of the first active part 311 in the Y-axis direction, if the width W1 of the second active part 312 in the X-axis direction is sufficiently greater than the width W3 of the first active part 311 in the X-axis direction, then in a top view observed along the +Z direction, the area of ​​the second active part 312 is also greater than the area of ​​the first active part 311.

[0110] Furthermore, in this embodiment, by making the length L2 of the second active portion 312 the same as the length L1 of the first active portion 311, and making the width W1 of the second active portion 312 greater than the width W3 of the first active portion 311, the area S1 of the second active portion 312 can be made larger than the area S3 of the first active portion 311 when viewed from above in the +Z direction, but this is not particularly limited. For example, the width W1 of the second active portion 312 can also be the same as the width W3 of the first active portion 311, and the length L1 of the second active portion 312 can be longer than the length L3 of the first active portion 311, thereby making the area S1 of the second active portion 312 greater than the area S3 of the first active portion 311. Alternatively, the area S1 of the second active portion 312 can be made larger than the area S3 of the first active portion 311 by making one of the width W1 and length L1 of the second active portion 312 smaller than the width W3 and length L3 of the first active portion 311, and making the other of the width W1 and length L1 of the second active portion 312 larger than the width W3 and length L3 of the first active portion 311.

[0111] Other implementation methods

[0112] The various embodiments of the present invention have been described above, but the basic structure of the present invention is not limited to the above content.

[0113] For example, in the embodiments described above, although in the first piezoelectric element 301, the first lower electrode 61 constitutes an independent electrode for each of the first active portions 311, and the first upper electrode 81 constitutes a common electrode for multiple first active portions 311, this is not particularly limited to this. Alternatively, the first lower electrode 61 may constitute a common electrode for multiple first active portions 311, and the first upper electrode 81 may constitute an independent electrode for each of the first active portions 311. Similarly, for the second piezoelectric element 302, the second lower electrode 62 may constitute a common electrode for multiple second active portions 312, and the second upper electrode 82 may constitute an independent electrode for each second active portion 312. Thus, when the first upper electrode 81 and the second upper electrode 82 are independent electrodes, by changing the width of the first upper electrode 81 and the second upper electrode 82 in the X-axis direction, the width of the second active portion 312 in the X-axis direction can be made greater than the width of the first active portion 311. In addition, by changing the area of ​​the first upper electrode 81 and the second upper electrode 82 when viewed from above in the +Z direction, the area of ​​the second active part 312 can be made larger than the area of ​​the first active part 311.

[0114] Furthermore, in the above embodiments, although the recovery path 124 is formed in the recess of the connecting plate 120, it is not particularly limited. The recovery path 124 may be provided through the connecting plate 120 in the Z-axis direction, or it may be provided on the pressure chamber substrate 10, or it may be provided on both the pressure chamber 12 and the connecting plate 120.

[0115] In addition, the liquid injection head H of each of the above embodiments is mounted on the liquid injection device 1. Figure 10 This is a diagram showing the schematic configuration of a liquid injection device 1 according to an embodiment of the present invention.

[0116] As shown in the figure, the liquid jetting device 1 is a so-called serial printer that prints by conveying a medium S along the X-axis and moving the liquid jetting head H back and forth along the Y-axis while jetting (also called jetting) liquid from the liquid jetting head H toward the medium S in the +Z direction. It should be noted that the medium S can be any material such as resin film or cloth, in addition to recording paper. Furthermore, the direction of the back-and-forth movement of the liquid jetting head H is not limited to the Y-axis direction; it can also be a direction inclined relative to both the X-axis and Y-axis directions.

[0117] The liquid injection device 1 includes a liquid injection head H, a liquid storage unit 3, a control unit 4, a conveying mechanism 5 for delivering the medium S, and a moving mechanism 6.

[0118] The liquid jet head H sprays the liquid supplied from the liquid storage unit 3 as droplets in the +Z direction.

[0119] The liquid storage unit 3 stores the liquid ejected from the liquid ejection head H. Examples of liquid storage units 3 include ink cartridges that can be detached from the liquid ejection device 1, ink bags in the shape of flexible films, and ink cans that can be refilled with ink.

[0120] The supply pipe Tin and the discharge pipe Tout are connected to the liquid storage section 3.

[0121] The supply pipe Tin is the pipe that supplies ink from the liquid storage section 3, which is set to a predetermined pressure by the pump 7, to the liquid jet head H. The discharge pipe Tout is the pipe that returns the ink recovered from the liquid jet head H to the liquid storage section 3.

[0122] Additionally, although not specifically illustrated, the liquid storage unit 3 can also be divided into a main ink tank and a secondary ink tank. Alternatively, the secondary ink tank can be connected to the liquid ejector head H, replenishing the liquid consumed by the liquid droplets ejected from the liquid ejector head H from the main ink tank to the secondary ink tank.

[0123] The control unit 4 includes, for example, a control device such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array), and a storage device such as a semiconductor memory. Additionally, the control unit 4 also includes a power supply device for supplying power from an external power source, such as a commercial power supply, to the various components of the liquid jetting device 1. The control unit 4 is electrically connected to the liquid jetting head H via the aforementioned flexible substrate 110. The control unit 4 executes the program stored in the storage device through the control device to comprehensively control the various components of the liquid jetting device 1.

[0124] The conveying mechanism 5 is a mechanism for conveying the medium S along the X-axis direction. For example, it has a conveying roller 5a, which is rotated by a conveying motor controlled by the control unit 4.

[0125] The moving mechanism 6 is a mechanism for reciprocating the liquid injection head H along the Y-axis direction. It includes a holding body 6a that holds the liquid injection head H and an annular belt, i.e., a conveyor belt 6b, that is, is mounted along the Y-axis direction. The control unit 4 controls the drive of a conveyor motor (not shown) to rotate the conveyor belt 6b, and moves the conveyor belt 6b and the holding body 6a, which fixes the liquid injection head H to the conveyor belt 6b, reciprocating along the Y-axis direction. It should be noted that the liquid storage unit 3 can also be mounted on the holding body 6a together with the liquid injection head H. Although the holding body 6a holds one liquid injection head H, it is also acceptable for the holding body 6a to hold two or more liquid injection heads H.

[0126] Under the control of the control unit 4, the liquid jet head H performs an ejection operation, which involves ejecting ink supplied from the liquid storage unit 3 from multiple nozzles 21 as ink droplets in the +Z direction. The control unit 4 functions as an ejection control unit to control the ink ejection from the liquid jet head H. The ejection operation of the liquid jet head H is performed in parallel with the transport of the medium S in the X-axis direction by the transport mechanism 5 and the reciprocating movement of the liquid jet head H in the Y-axis direction by the moving mechanism 6, thereby performing what is known as printing by applying ink to the medium S.

[0127] It should be pointed out that, in Figure 10 In the example shown, the liquid jetting device 1 illustrates a device in which the liquid jetting head H is mounted on the holder 6a and moves along the main scanning direction, but it is not particularly limited. For example, the invention can also be applied to a so-called line printer in which the liquid jetting head H is fixed and printing is performed only by moving the medium S along the sub-scanning direction.

[0128] Furthermore, this invention is broadly applicable to the entire category of liquid ejection heads and liquid ejection devices, and can naturally also be applied to liquid ejection heads and liquid ejection devices for ejecting liquids other than ink. Other examples of liquid ejection heads include various recording heads used in image recording devices such as printers, color material ejection heads used in the manufacture of color filters for liquid crystal displays, electrode material ejection heads used in the formation of electrodes for organic EL displays and FED (field emission displays), and biological organic matter ejection heads used in the manufacture of biochips; these can also be applied to liquid ejection devices equipped with the aforementioned liquid ejection heads.

[0129] appendix

[0130] Based on the methods illustrated above, the following structure can be understood, for example.

[0131] Option 1, as a preferred embodiment, involves a liquid injection head comprising: a plurality of nozzles arranged along a first direction; a first piezoelectric element; a second piezoelectric element; a pressure chamber driven by the first piezoelectric element to impart pressure for injecting liquid from the nozzles; and a detection chamber for detecting residual vibrations of the pressure of the liquid imparted by the pressure chamber by the second piezoelectric element. In a top-view view, the width of the active portion of the second piezoelectric element, i.e., the second active portion, in the first direction is greater than the width of the active portion of the first piezoelectric element, i.e., the first active portion, in the first direction.

[0132] Accordingly, by making the width of the second active portion of the second piezoelectric element greater than the width of the first active portion of the first piezoelectric element in the first direction, the amount of strain in the second active portion can be increased, and the voltage output by the second active portion due to pressure changes in the detection chamber can be increased, thereby improving the detection accuracy of pressure changes in the detection chamber. Furthermore, by making the width of the first active portion less than the width of the second active portion in the first direction, the distance between two adjacent first active portions along the first direction can be increased. Therefore, in two adjacent first active portions, since the vibration of one first active portion attenuates before being transmitted to the other first active portion, the influence of the vibration of one first active portion on the other first active portion 311, i.e., so-called crosstalk, can be suppressed.

[0133] In embodiment 2, a specific example of embodiment 1, the liquid injection head includes: a plurality of first active portions, including the first active portions; a plurality of second active portions, including the second active portions; a first independent electrode independently connected to the plurality of first active portions; and a second independent electrode independently connected to the plurality of second active portions, wherein the width of the second independent electrode in the first direction is greater than the width of the first independent electrode in the first direction. Accordingly, the widths of the first active portions and the second active portions can be easily adjusted by varying the widths of the first independent electrode and the second independent electrode.

[0134] In Scheme 3, a specific example of Scheme 1, when the width of the second active part in the first direction is set to W1, the width of the upper surface of the detection chamber in the first direction is set to W2, the width of the first active part in the first direction is set to W3, and the width of the upper surface of the pressure chamber in the first direction is set to W4, W1 / W2 > W3 / W4 holds true. Accordingly, since the second active part can be configured with the largest possible width relative to the detection chamber, which has a finite width in the first direction, the amount of strain in the second active part can be increased, thereby improving the detection accuracy of the residual vibration of the second active part.

[0135] In Scheme 4, a specific example of Scheme 1, from a top-down view, when the area of ​​the second active part is set as S1, the area of ​​the detection chamber as S2, the area of ​​the first active part as S3, and the area of ​​the pressure chamber as S4, S1 / S2 > S3 / S4 holds true. Accordingly, the second active part can be provided with the largest possible area relative to the detection chamber, which has a limited area. Therefore, the amount of strain in the second active part can be increased to improve the detection accuracy of the residual vibration of the second active part. Furthermore, since the area S3 of the first active part can be provided with a relatively small area relative to the area S4 of the pressure chamber, the deformation of the first active part 311 can be reduced, and in two adjacent first active parts 311, the influence of the vibration of one first active part on the other, i.e., crosstalk, can be suppressed.

[0136] In embodiment 5, a specific example of embodiment 1, the liquid injection head includes a plurality of first active portions, each including the first active portion, wherein the distance between the plurality of first active portions in the first direction is greater than the width of the first active portion in the first direction. Accordingly, the distance between two adjacent first active portions along the first direction can be increased, and crosstalk between the two first active portions can be suppressed.

[0137] In embodiment 6, a specific example of embodiment 5, the liquid injection head includes a plurality of second active portions, each comprising a second active portion. The width of the second active portion in the first direction is greater than the distance between the plurality of second active portions in the first direction. Accordingly, by making the width of the second active portion in the first direction greater than the distance between adjacent second active portions along the first direction, the width of the second active portion in the first direction can be maximized. Therefore, the amount of strain in the second active portion can be increased, the output voltage can be increased, and the detection accuracy of residual vibration can be improved.

[0138] In Scheme 7, a specific example of Scheme 1, the detection chamber is smaller than the pressure chamber. Accordingly, by relatively reducing the size of the detection chamber, the plasticity of the detection chamber and the overall plasticity of the independent flow path can be reduced. Therefore, high-frequency driving of the first active part is possible. Furthermore, if the plasticity of the detection chamber is reduced, the second active part corresponding to the detection chamber becomes less susceptible to strain. However, by increasing the width of the second active part in the first direction, the amount of strain increases, thereby improving the detection accuracy of the residual vibration of the second active part.

[0139] In embodiment 8, a specific example of embodiment 1, the liquid jet head includes: a pressure chamber substrate on which the pressure chamber and the detection chamber are disposed; and a vibrating plate disposed on the pressure chamber substrate, defining the pressure chamber and the detection chamber. The pressure chamber substrate has a partition wall disposed between the pressure chamber and the detection chamber, defining the sides of the pressure chamber and the detection chamber. Accordingly, by using the partition wall to divide the detection chamber and the pressure chamber, the second active part can be made less susceptible to absorbing pressure fluctuations in the liquid within the pressure chamber caused by the first active part. Therefore, the first active part can be driven at high frequency, and droplets can be ejected at high frequency.

[0140] In embodiment 9, a specific example of embodiment 1, the liquid injection head has an independent flow path communicating independently with the plurality of nozzles, and the pressure chamber and the detection chamber are included in the independent flow path. Accordingly, since the pressure chamber and the detection chamber are included in independent flow paths rather than a common flow path, residual vibration of each pressure chamber can be detected independently by the second active part. Therefore, poor ejection of droplets from each nozzle communicating with each pressure chamber can be detected independently by the second active part.

[0141] In embodiment 10, a specific example of embodiment 9, the independent flow path has an independent supply path and an independent recovery path. The independent supply path supplies liquid to the nozzle, and the independent recovery path recovers liquid that is not ejected from the nozzle. The detection chamber is included in the independent recovery path. Accordingly, by placing the detection chamber in the independent recovery path, compared to placing the detection chamber in the independent supply path, the flow path length of the independent supply path can be shortened, the pressure loss in the independent supply path can be reduced, and poor liquid supply can be suppressed. Furthermore, by placing the detection chamber in the independent recovery path, the second active unit can independently detect residual vibration in each pressure chamber and can independently detect poor ejection of droplets from each nozzle.

[0142] As a preferred embodiment, the liquid injection head of embodiment 11 includes: a plurality of nozzles arranged along a first direction; a first piezoelectric element; a second piezoelectric element; a pressure chamber driven by the first piezoelectric element to impart pressure for injecting liquid from the nozzles; and a detection chamber for detecting residual vibrations of the pressure of the liquid imparted by the pressure chamber by the second piezoelectric element, wherein, in top view, the area of ​​the active portion of the second piezoelectric element, i.e., the second active portion, is larger than the area of ​​the active portion of the first piezoelectric element, i.e., the first active portion.

[0143] Accordingly, by making the area of ​​the second active part larger than that of the first active part, the area of ​​the second active part can be relatively increased, thereby increasing the amount of strain and increasing the voltage output from the second active part, thus improving the detection accuracy of the residual vibration of the second active part. Furthermore, by reducing the area of ​​the first active part, the deformation of the first active part can be reduced, and crosstalk (i.e., the vibration of one first active part affecting the other first active part) can be suppressed between two adjacent first active parts.

[0144] As a preferred embodiment, embodiment 12 relates to a liquid injection device comprising a liquid injection head as described in any of the above embodiments and a liquid storage section for supplying liquid to the liquid injection head.

[0145] Accordingly, the residual vibration of pressure change of liquid in pressure chamber can be detected with high precision by the second active part, and the poor ejection of droplets from nozzle can be detected with high precision.

Claims

1. A liquid injection head, characterized in that, have: Multiple nozzles are arranged along a first direction; First piezoelectric element; Second piezoelectric element; The pressure chamber, driven by the first piezoelectric element, imparts pressure for ejecting liquid from the nozzle; as well as The detection chamber uses the second piezoelectric element to detect residual vibrations caused by the pressure applied to the liquid in the pressure chamber. When viewed from above, the width of the active portion of the second piezoelectric element, i.e., the second active portion, in the first direction is greater than the width of the active portion of the first piezoelectric element, i.e., the first active portion, in the first direction.

2. The liquid injection head according to claim 1, characterized in that, The liquid injection head includes: Including a plurality of first active units, including the first active unit; Including a plurality of second active units, including the second active unit; The first independent electrode is independently connected to the plurality of first active parts; as well as The second independent electrode is independently connected to the plurality of second active parts. The width of the second independent electrode in the first direction is greater than the width of the first independent electrode in the first direction.

3. The liquid injection head according to claim 1, characterized in that, When the width of the second active part in the first direction is set to W1, the width of the upper surface of the detection chamber in the first direction is set to W2, the width of the first active part in the first direction is set to W3, and the width of the upper surface of the pressure chamber in the first direction is set to W4, W1 / W2 > W3 / W4 holds true.

4. The liquid injection head according to claim 1, characterized in that, From an overhead view When the area of ​​the second active part is set as S1, the area of ​​the detection chamber is set as S2, the area of ​​the first active part is set as S3, and the area of ​​the pressure chamber is set as S4, S1 / S2 > S3 / S4 holds true.

5. The liquid injection head according to claim 1, characterized in that, The liquid injection head includes a plurality of first active parts, including the first active part. The distance between the plurality of first active units in the first direction is greater than the width of the first active unit in the first direction.

6. The liquid injection head according to claim 5, characterized in that, The liquid injection head includes a plurality of second active parts, each including the second active part. The width of the second active portion in the first direction is greater than the distance between the plurality of second active portions in the first direction.

7. The liquid injection head according to claim 1, characterized in that, The detection chamber is smaller than the pressure chamber.

8. The liquid injection head according to claim 1, characterized in that, The liquid injection head includes: A pressure chamber substrate is provided with the pressure chamber and the detection chamber; and A vibrating plate, disposed on the pressure chamber base plate, defines the pressure chamber and the detection chamber. The pressure chamber substrate has a partition wall disposed between the pressure chamber and the detection chamber, and defines the sides of the pressure chamber and the detection chamber.

9. The liquid injection head according to claim 1, characterized in that, The liquid injection head has an independent flow path that is independently connected to the plurality of nozzles. The pressure chamber and the detection chamber are included in the independent flow path.

10. The liquid injection head according to claim 9, characterized in that, The independent flow path has an independent supply path and an independent recovery path. The independent supply path supplies liquid to the nozzle, and the independent recovery path recovers liquid that was not ejected from the nozzle. The detection chamber is included in the independent recovery path.

11. A liquid injection head, characterized in that, have: Multiple nozzles are arranged along a first direction; First piezoelectric element; Second piezoelectric element; The pressure chamber, driven by the first piezoelectric element, imparts pressure for ejecting liquid from the nozzle; as well as The detection chamber uses the second piezoelectric element to detect residual vibrations caused by the pressure applied to the liquid in the pressure chamber. When viewed from above, the area of ​​the active part of the second piezoelectric element, i.e., the second active part, is larger than the area of ​​the active part of the first piezoelectric element, i.e., the first active part.

12. A liquid injection device, characterized in that, have: The liquid injection head according to any one of claims 1 to 11 and the liquid storage section for supplying liquid to the liquid injection head.

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