Liquid dispensing head and recording device

Abstract

This liquid dispensing head is provided with a vibration plate, a plurality of pressure chambers, a plurality of piezoelectric elements, and a sealing member. The vibration plate has a first surface and a second surface positioned on the opposite side to the first surface. The plurality of pressure chambers face the first surface and are positioned along one direction. The plurality of piezoelectric elements are positioned on the second surface so as to respectively overlap the plurality of pressure chambers in plan view. The sealing member is a frame-shaped sealing member and is positioned on the second surface so as to surround the plurality of piezoelectric elements in plan view.

Description

【Technical Field】 [Figure 1] , 【0006】 , , 【0001】 The disclosed embodiments relate to a liquid ejection head and a recording apparatus. 【Background Art】 【0002】 As a printing apparatus which is one of recording apparatuses for recording images and characters, an inkjet printer or an inkjet plotter using an inkjet recording method is known. Such an inkjet printing apparatus (recording apparatus) is equipped with a liquid ejection head for ejecting a liquid. 【0003】 In such a liquid ejection head, a sealing member is provided so as to individually surround each piezoelectric element on a diaphragm provided with a plurality of piezoelectric elements for ejecting a liquid, thereby protecting each piezoelectric element from liquid leakage from the flow path and moisture in the outside air (for example, see Patent Document 1). 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2021-176710 【Summary of the Invention】 【0005】 A liquid ejection head according to an aspect of the embodiment includes a diaphragm, a plurality of pressure chambers, a plurality of piezoelectric elements, and a sealing member. The diaphragm has a first surface and a second surface located on the side opposite to the first surface. The plurality of pressure chambers face the first surface and are arranged side by side in one direction. The plurality of piezoelectric elements are located on the second surface so as to overlap the plurality of pressure chambers in a plan view. The sealing member is a frame-shaped sealing member and is located on the second surface so as to surround the plurality of piezoelectric elements in a plan view. 【Brief Description of the Drawings】 【0006】 [Figure 1] FIG. 1 is a front view schematically showing a schematic front of a printer according to an embodiment. [Figure 2] Figure 2 is a schematic plan view showing a general plan of the printer according to this embodiment. [Figure 3] Figure 3 is a plan view showing a schematic configuration of the liquid discharge head according to the embodiment. [Figure 4] Figure 4 is a cross-sectional view along the line IV-IV shown in Figure 3. [Figure 5] Figure 5 is a plan view showing a schematic configuration of a liquid discharge head according to another embodiment 1. [Figure 6A] Figure 6A is a plan view showing a schematic configuration of a liquid discharge head according to another embodiment 2. [Figure 6B] Figure 6B is a plan view showing a schematic configuration of a liquid discharge head according to another embodiment 3. [Figure 7] Figure 7 is a cross-sectional view along the line VII-VII shown in Figure 6A or Figure 6B. [Modes for carrying out the invention] 【0007】 The embodiments of the liquid dispensing head and recording device disclosed herein will be described below with reference to the attached drawings. However, the embodiments described below are not limiting to this disclosure. Furthermore, it should be noted that the drawings are schematic, and the dimensional relationships and ratios of each element may differ from reality. In addition, there may be differences in dimensional relationships and ratios between different parts of the drawings. 【0008】 Furthermore, in the embodiments described below, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not require strict adherence to "constant," "orthogonal," "perpendicular," or "parallel" conditions. In other words, each of the above expressions allows for deviations such as manufacturing accuracy or installation accuracy. 【0009】 [Embodiment] <Printer Configuration> An overview of a printer 1, which is an example of a recording device according to the embodiment, will be described using Figures 1 and 2. Figure 1 is a schematic front view showing a general front view of the printer 1 according to the embodiment. Figure 2 is a schematic plan view showing a general top view of the printer 1 according to the embodiment. The printer 1 according to the embodiment is, for example, a color inkjet printer equipped with an inkjet head, which is a liquid ejection head. 【0010】 As shown in Figure 1, the printer 1 comprises a paper feed roller 2, a guide roller 3, a coating machine 4, a head case 5, multiple transport rollers 6, multiple frames 7, multiple liquid discharge heads 8, a transport roller 9, a dryer 10, a transport roller 11, a sensor unit 12, and a recovery roller 13. 【0011】 Furthermore, the printer 1 has a control unit 14 that controls each part of the printer 1. The control unit 14 controls the operation of the paper feed roller 2, guide roller 3, coating machine 4, head case 5, multiple transport rollers 6, multiple frames 7, multiple liquid discharge heads 8, transport roller 9, dryer 10, transport roller 11, sensor unit 12, and recovery roller 13. 【0012】 Printer 1 records images and characters on the printing paper P by causing droplets ejected by the liquid ejection head 8 to land on the paper P. Before use, the printing paper P is wound onto the paper feed roller 2 in a retractable state. Printer 1 transports the printing paper P from the paper feed roller 2 to the inside of the head case 5 via the guide roller 3 and the coating machine 4. 【0013】 The coating machine 4 uniformly applies the coating agent to the printing paper P. This allows the printing paper P to undergo surface treatment, thereby improving the print quality of the printer 1. 【0014】 The head case 5 houses a plurality of conveying rollers 6, a plurality of frames 7, and a plurality of liquid ejection heads 8. Inside the head case 5, except for a part such as a portion where the printing paper P enters and exits, which is connected to the outside, a space isolated from the outside is formed. 【0015】 The internal space of the head case 5 is controlled by the control unit 14 for at least one of the control factors such as temperature, humidity, and air pressure, as required. The conveying roller 6 conveys the printing paper P inside the head case 5 to the vicinity of the liquid ejection head 8. 【0016】 The frame 7 is, for example, a rectangular flat plate and is positioned close above the printing paper P conveyed by the conveying roller 6. Also, as shown in FIG. 2, the frame 7 is positioned such that its longitudinal direction is orthogonal to the conveying direction of the printing paper P. And inside the head case 5, a plurality (for example, four) of frames 7 are positioned at a predetermined interval along the conveying direction of the printing paper P. 【0017】 In the following description, the conveying direction of the printing paper P may be referred to as the "sub-scanning direction", and the direction orthogonal to such sub-scanning direction and parallel to the printing paper P may be referred to as the "main scanning direction". 【0018】 The liquid ejection head 8 is a so-called circulation type liquid ejection head that ejects liquid while circulating the liquid inside. The liquid ejection head 8 is supplied with liquid, for example, ink, from a liquid tank of a circulation device (not shown). The liquid ejection head 8 ejects the liquid supplied from the liquid tank of such a circulation device. The liquid ejection head 8 collects the liquid that has not been ejected and sends the collected liquid back to the liquid tank of the circulation device. 【0019】 The control unit 14 controls the liquid ejection head 8 based on data such as images and characters, and causes the liquid (droplets) to be ejected toward the printing paper P. The distance between the liquid ejection head 8 and the printing paper P is, for example, about 0.5 to 20 mm. 【0020】 The liquid ejection head 8 is fixed to the frame 7. The liquid ejection head 8 is fixed to the frame 7, for example, at both longitudinal ends. The liquid ejection head 8 is fixed to the frame 7 such that the longitudinal direction is parallel to the main scanning direction. 【0021】 That is, the printer 1 according to the embodiment is a so-called line printer in which the liquid ejection head 8 is fixed inside the printer 1. Note that the printer 1 according to the embodiment is not limited to a line printer and may be a so-called serial printer. 【0022】 A serial printer is a printer that alternately performs an operation of recording while moving the liquid ejection head 8 in a direction intersecting the conveyance direction of the printing paper P, for example, a direction substantially orthogonal to it, and the conveyance of the printing paper P. 【0023】 As shown in FIG. 2, a plurality (for example, five) of liquid ejection heads 8 are provided on one frame 7. FIG. 2 shows an example in which two liquid ejection heads 8 are arranged in front and three liquid ejection heads 8 are arranged in the rear in the sub-scanning direction, and the liquid ejection heads 8 are arranged so that the centers of the respective liquid ejection heads 8 do not overlap in the sub-scanning direction. 【0024】 And, a head group 8A is constituted by a plurality of liquid ejection heads 8 provided on one frame 7. The four head groups 8A are positioned along the sub-scanning direction. The same color ink is supplied to the liquid ejection heads 8 belonging to the same head group 8A. Thereby, the printer 1 can perform printing with four-color ink using the four head groups 8A. 【0025】 The colors of the inks ejected from each head group 8A are, for example, magenta (M), yellow (Y), cyan (C), and black (K). The control unit 14 can print a color image on the printing paper P by controlling each head group 8A to eject a plurality of colors of ink onto the printing paper P. 【0026】 Furthermore, in order to treat the surface of the printing paper P, a coating agent may be dispensed onto the printing paper P from the liquid ejection head 8. 【0027】 Furthermore, the number of liquid ejection heads 8 included in one head group 8A, and the number of head groups 8A installed in printer 1, can be appropriately changed depending on the object to be printed or the printing conditions. For example, if the color to be printed on the printing paper P is a single color, and the printing is limited to the area that can be printed with one liquid ejection head 8 or head group 8A, then the number of liquid ejection heads 8 or head group 8A installed in printer 1 may be as small as one. 【0028】 The printed paper P, which has been processed inside the head case 5, is transported to the outside of the head case 5 by the transport roller 9 and passes through the inside of the dryer 10. The dryer 10 dries the printed paper P. The dried printed paper P is transported by the transport roller 11 and collected by the recovery roller 13. 【0029】 In printer 1, drying the printing paper P in the dryer 10 prevents the overlapping printing paper P from sticking together and prevents friction from undried liquid in the recovery roller 13. 【0030】 The sensor unit 12 is composed of, for example, a position sensor, a speed sensor, a temperature sensor, and so on. Based on the information from the sensor unit 12, the control unit 14 can determine the state of each part of the printer 1 and control each part of the printer 1. 【0031】 The printer 1 described so far has shown the case where printing paper P is used as the printing target (i.e., recording medium), but the printing target in printer 1 is not limited to printing paper P; a roll of cloth or other material may also be used as the printing target. 【0032】 Furthermore, the printer 1 described above may transport the printing paper P on a conveyor belt instead of directly transporting it. By using a conveyor belt, the printer 1 can print on sheets of paper or cut cloth, wood, tiles, etc. 【0033】 Furthermore, the printer 1 described above may print wiring patterns for electronic devices, etc., by ejecting a liquid containing conductive particles from the liquid ejection head 8. 【0034】 Furthermore, the printer 1 described above may also produce chemical products by ejecting a predetermined amount of liquid chemical agent or a liquid containing a chemical agent from the liquid ejection head 8 toward a reaction vessel or the like. 【0035】 Furthermore, the printer 1 described above may also include a cleaning unit for cleaning the liquid ejection head 8. The cleaning unit cleans the liquid ejection head 8, for example, by wiping or capping. 【0036】 Wiping is a process that removes liquid adhering to the surface of the liquid dispensing head 8 by wiping the surface of the liquid dispensing part of the liquid dispensing head 8 with a flexible wiper. 【0037】 Furthermore, the capping process is carried out, for example, as follows: First, a cap is placed over the part of the liquid dispensing head 8 from which the liquid is dispensed, for example, the bottom surface 8e of the liquid dispensing head 8 (see Figure 4) (this is called capping). This creates a substantially sealed space between the bottom surface 8e and the cap. 【0038】 Next, the liquid is repeatedly discharged into this sealed space. This removes any liquid with a higher viscosity than standard and any foreign matter that may have been clogging the nozzle 28 (see Figure 4). 【0039】 <Configuration of the liquid dispensing head> Next, the configuration of the liquid dispensing head 8 according to the embodiment will be described with reference to Figures 3 and 4. Figure 3 is a plan view showing a schematic configuration of the liquid dispensing head according to the embodiment. Figure 4 is a cross-sectional view along the line IV-IV shown in Figure 3. 【0040】 For the sake of clarity, Figure 3 illustrates a three-dimensional Cartesian coordinate system that includes the Z-axis, with the vertically upward direction being the positive direction. This Cartesian coordinate system may also be shown in other diagrams used in the following explanation. Furthermore, for convenience, in the following explanation, the direction in which the bottom surface 8e of the liquid discharge head 8 (see Figure 4) is located, i.e., the negative Z-axis direction, may be referred to as "down" or "downward," and the positive Z-axis direction may be referred to as "up" or "upward." 【0041】 As shown in Figures 3 and 4, the liquid discharge head 8 comprises a diaphragm 21, a plurality of pressure chambers 22, a pressure chamber girder 23, a plurality of piezoelectric elements 24, a sealing member 25, a flow path member 26, and a nozzle layer 27. 【0042】 The diaphragm 21 is located on a plurality of pressure chambers 22 and pressure chamber girders 23. The diaphragm 21 is a plate-like member formed of, for example, silicon, and has a first surface 21a which is a main surface and a second surface 21b which is located on the opposite side of the first surface 21a. 【0043】 Multiple pressure chambers 22 face the first surface 21a of the diaphragm 21. Each pressure chamber 22 is a hollow region with a roughly rectangular planar shape and rounded corners. As shown in Figure 3, the multiple pressure chambers 22 are arranged in the X-axis direction with their longitudinal direction aligned with the Y-axis direction. Liquid is supplied into each pressure chamber 22 through the flow path 26a of the flow path member 26 and the opening 21c of the diaphragm 21 (see Figure 4). 【0044】 The pressure chamber girders 23 are located around each pressure chamber 22, separating each pressure chamber 22 from the others. 【0045】 Multiple piezoelectric elements 24 are positioned on the second surface 21b of the diaphragm 21 so as to overlap with multiple pressure chambers 22 in a plan view. Each piezoelectric element 24 deforms in the Z-axis direction (vertical direction) together with the diaphragm 21 when energized, thereby changing the internal pressure of the corresponding pressure chamber 22 via the diaphragm 21. 【0046】 The sealing member 25 has an overall frame shape and is positioned on the second surface 21b of the diaphragm 21 so as to surround the multiple piezoelectric elements 24 in a plan view. In other words, the sealing member 25 seals the multiple piezoelectric elements 24 together. By positioning the sealing member 25 to surround the multiple piezoelectric elements 24, the space occupied by the sealing member 25 on the diaphragm 21 (second surface 21b) can be reduced compared to a structure in which the sealing member 25 surrounds each piezoelectric element 24 individually. As a result, miniaturization of the liquid discharge head 8 in the planar direction can be promoted. 【0047】 Furthermore, by positioning the sealing member 25 to surround the entirety of the multiple piezoelectric elements 24, the multiple piezoelectric elements 24 can be arranged in close proximity to each other on the diaphragm 21 (second surface 21b), thereby achieving high integration of the piezoelectric elements 24 in the planar direction of the liquid discharge head 8. 【0048】 Furthermore, by positioning the sealing member 25 to surround the entirety of the multiple piezoelectric elements 24, the contact area when joining the diaphragm 21 and the flow channel member 26 via the sealing member 25 is minimized, thereby suppressing the occurrence of defects in the sealing member 25. This improves the reliability of the connection provided by the sealing member 25. 【0049】 The sealing member 25 is made of metal. The metal forming the sealing member 25 is preferably a metal that has excellent resistance to the liquid supplied into the interior of each pressure chamber 22 through the flow path 26a of the flow path member 26 and the opening 21c of the diaphragm 21. As such a metal, for example, gold (Au) or an alloy containing gold (Au) can be used. As an alloy containing gold (Au), for example, a gold (Au)-tin (Sn) alloy, a gold (Au)-silicon (Si) alloy, or a gold (Au)-germanium (Ge) alloy can be used. Since the sealing member 25 is made of metal, its resistance to the liquid supplied into the interior of each pressure chamber 22 is improved, and thus the reliability of the connection by the sealing member 25 is further improved. 【0050】 Furthermore, the sealing member 25 may be formed from a resin, such as benzocyclobutene resin, instead of metal. When a resin such as benzocyclobutene resin is used, the sealing member 25 can be formed and sealed at a lower temperature compared to when metal is used, thus reducing the thermal load on the piezoelectric element 24. In this case, it is advantageous for maintaining the desired element characteristics of the piezoelectric element 24 after sealing. 【0051】 The flow channel member 26 is joined to the second surface 21b of the diaphragm 21 via a sealing member 25. The joining of the flow channel member 26 and the second surface 21b via the sealing member 25 is performed, for example, by diffusion bonding. 【0052】 The flow channel member 26 has a flow channel 26a that penetrates the flow channel member 26 in the thickness direction (Z-axis direction). Since the liquid discharge head 8 is a circulating type liquid discharge head, the flow channel member 26 has two flow channels 26a corresponding to one pressure chamber 22. One of the two flow channels 26a is a supply flow channel for supplying liquid to the pressure chamber 22 inside the head 8, and the other is a recovery flow channel for recovering liquid from the pressure chamber 22 inside the head 8. The flow channel member 26 also has a cavity (not indicated) on its lower surface (the surface facing the second surface 21b) for housing and sealing the piezoelectric element 24. 【0053】 The nozzle layer 27 is located on the bottom surface 8e side of the liquid discharge head 8 and closes the lower end of the pressure chamber 22. The nozzle layer 27 has nozzles 28 corresponding to each of the multiple pressure chambers 22. The nozzles 28 are through holes that penetrate the nozzle layer 27 in the thickness direction (Z-axis direction). The liquid supplied into each pressure chamber 22 is discharged to the outside as droplets from the nozzles 28 when pressure is applied to the pressure chamber 22 via the diaphragm 21 due to the deformation of the piezoelectric element 24. 【0054】 Here, the details of the joint between the flow channel member 26 and the second surface 21b of the diaphragm 21 via the sealing member 25 will be further explained with reference to Figures 3 and 4. 【0055】 As shown in Figure 4, the diaphragm 21 has through-hole openings 21c at positions corresponding to the flow channels 26a on the second surface 21b, connecting the flow channels 26a to each pressure chamber 22. Since the flow channel member 26 has two flow channels 26a corresponding to one pressure chamber 22, the diaphragm 21 has two openings 21c at positions corresponding to the two flow channels 26a on the second surface 21b, respectively, connecting the two flow channels 26a to the corresponding pressure chamber 22. 【0056】 As shown in Figures 3 and 4, the sealing member 25 has a ring-shaped sealing portion 251 positioned between the second surface 21b of the diaphragm 21 and the flow path member 26, so as to surround the periphery of the flow path 26a and the opening 21c in a plan view. Since the flow path member 26 has two flow paths 26a corresponding to one pressure chamber 22, the sealing member 25 has two sealing portions 251 corresponding to one pressure chamber 22. The sealing portions 251 seal the periphery of the flow path 26a and the opening 21c. Because the sealing member 25 has sealing portions 251, the sealing of multiple piezoelectric elements 24 and the sealing of the periphery of the flow path 26a and the opening 21c are performed collectively by a single sealing member 25, thereby promoting miniaturization of the liquid discharge head 8 in the planar direction. Furthermore, since multiple sealing portions 251 are connected to each other and form part of a frame-shaped sealing member 25, the sealing of multiple piezoelectric elements 24 and the sealing of the periphery of the flow path 26a and opening 21c can be performed simultaneously in that portion, thus reducing the amount of sealing material. 【0057】 Furthermore, as shown in Figure 3, the sealing member 25 is formed in a rectangular frame shape including a long side and a short side in a plan view. The long side of the sealing member 25 extends along the X-axis. The short side of the sealing member 25 extends along the Y-axis. The width W1 of at least a portion of the long side of the sealing member 25 is greater than the width W2 of the short side of the sealing member 25. In the example in Figure 3, a ring-shaped sealing portion 251 is formed on a portion of the long side of the sealing member 25, and the width W1 corresponding to the outer diameter of the sealing portion 251 is greater than the width W2. Because the width W1 is greater than the width W2, the contact area per unit length between the long side of the sealing member 25 including the portion with width W1 and the second surface 21b is greater than the contact area per unit length between the short side of the sealing member 25 with width W2 and the second surface 21b. Thermal stress caused by the difference in thermal expansion coefficients between the sealing member 25 and the diaphragm 21 tends to be greater on the long side of the sealing member 25 than on the short side. In contrast, since the bonding area per unit length of the long side of the sealing member 25 is larger than the bonding area per unit length of the short side, even when thermal stress caused by the difference in thermal expansion coefficients between the sealing member 25 and the diaphragm 21 is applied more strongly to the long side of the sealing member 25 than to the short side, the occurrence of damage to the long side of the sealing member 25 is reduced. Therefore, the reliability of the connection by the sealing member 25 is improved. 【0058】 Furthermore, the corners of the rectangular frame-shaped sealing member 25 may be rounded, as shown in Figure 3. By rounding the corners of the sealing member 25, the concentration of thermal stress at the corners caused by the difference in thermal expansion coefficients between the sealing member 25 and the diaphragm 21 can be mitigated, thereby reducing the occurrence of damage at the corners of the sealing member 25. This also improves the reliability of the connection provided by the sealing member 25. 【0059】 Figures 3 and 4 show an example of the configuration of the liquid dispensing head 8. The liquid dispensing head 8 may further include components other than those shown in Figures 3 and 4. 【0060】 [Another embodiment] Figure 5 is a plan view showing a schematic configuration of a liquid discharge head 8 according to another embodiment 1. As shown in Figure 5, the sealing member 25 in another embodiment 1 is electrically connected to a ground electrode G (hatching omitted). The ground electrode G is formed, for example, on the second surface 21b of the diaphragm 21 (see Figure 4) and is connected to the ground potential. The sealing member 25 is connected to such ground electrode G via ground wiring 25a. 【0061】 Here, the liquid supplied into each pressure chamber 22 through the flow path 26a of the flow channel member 26 and the opening 21c of the diaphragm 21 contains, for example, a dispersant to disperse the components in the liquid. The dispersant contained in the liquid is electrically charged, and if such charge accumulates due to electrical attraction with the sealing member 25 surrounding the periphery of the flow path 26a and the opening 21c, the components in the liquid may aggregate against the sealing member 25 (sealing portion 251). In contrast, in another embodiment 1, the sealing member 25 is connected to the ground electrode G, so that the charge accumulated on the sealing member 25 is released to the ground electrode G, thereby reducing the aggregation of components in the liquid against the sealing member 25 (sealing portion 251). 【0062】 Figure 6A is a plan view showing a schematic configuration of a liquid dispensing head 8 according to another embodiment 2. Figure 6B is a plan view showing a schematic configuration of a liquid dispensing head 8 according to another embodiment 3. Figure 7 is a cross-sectional view along line VII-VII shown in Figure 6A or Figure 6B. The liquid dispensing head 8 shown in Figures 6A, 6B, and 7 is a so-called non-recirculating type liquid dispensing head that dispenses the supplied liquid without recovering it. In this case, the liquid dispensing head 8 is supplied with liquid, for example, ink, from a liquid tank (not shown). The liquid dispensing head 8 dispenses the liquid supplied from the liquid tank without recirculating and recovering it. 【0063】 Since the liquid discharge head 8 is a non-circulating liquid discharge head, the flow path member 26 has one flow path 26a corresponding to one pressure chamber 22, as shown in Figures 6A and 6B. This flow path 26a is a supply flow path for supplying liquid to the pressure chamber 22 inside the head 8. 【0064】 As shown in Figure 7, the diaphragm 21 has through-hole openings 21c at positions corresponding to the flow path 26a on the second surface 21b, connecting the flow path 26a to each pressure chamber 22. In another embodiment 2 shown in Figure 6A and another embodiment 3 shown in Figure 6B, the openings 21c only need to connect one pressure chamber 22 to one corresponding flow path 26a. Therefore, it is not necessary to continuously form openings 21c on both long sides of the sealing member 25 corresponding to each pressure chamber 22, as in the example embodiment. Accordingly, in another embodiment 2, openings 21c and sealing portions 251 are arranged alternately on both long sides of the sealing member 25 corresponding to each pressure chamber 22. In another embodiment 3, openings 21c and sealing portions 251 are arranged continuously on one long side of the sealing member 25 corresponding to each pressure chamber 22, as in the example embodiment. 【0065】 As shown in Figures 6A, 6B, and 7, the sealing member 25 has a ring-shaped sealing portion 251 positioned between the second surface 21b of the diaphragm 21 and the flow path member 26 so as to surround the periphery of the flow path 26a and the opening 21c in a plan view. The sealing portion 251 seals the periphery of the flow path 26a and the opening 21c. Because the sealing member 25 has a sealing portion 251, the sealing of the multiple piezoelectric elements 24 and the sealing of the periphery of the flow path 26a and the opening 21c are performed collectively by a single sealing member 25. This promotes miniaturization of the liquid discharge head 8 in the planar direction. 【0066】 In another embodiment 2, the openings 21c and sealing portions 251 are alternately arranged on both long sides of the sealing member 25. Therefore, the gaps between the sealing portions 251, which are wider than those in the example embodiment and another embodiment 3, can be connected by a pattern of a desired width, such as the same width as or wider than the width of the short side of the sealing member 25, to form a frame-shaped sealing member 25. In this other embodiment 2, there is more leeway in the arrangement and routing of the flow path 26a, which has the advantage of greater design freedom for the flow path 26a in the head. 【0067】 Furthermore, in another embodiment 3, the opening 21c and the sealing portion 251 are arranged continuously with one of the long sides of the sealing member 25, so the sealing portion 251 can be formed in the same way as the long side in the example embodiment. In this other embodiment 3, the arrangement and routing of the flow path 26a can be aligned throughout the entire head, which has the advantage of simplifying the design and manufacture of the flow path 26a and enabling smooth ink supply and ejection throughout the entire head. 【0068】 As described above, the liquid discharge head according to the embodiment (for example, liquid discharge head 8) comprises a diaphragm (for example, diaphragm 21), a plurality of pressure chambers (for example, pressure chambers 22), a plurality of piezoelectric elements (for example, piezoelectric elements 24), and a sealing member (for example, sealing member 25). The diaphragm has a first surface (for example, first surface 21a) and a second surface (for example, second surface 21b) located opposite to the first surface. The plurality of pressure chambers face the first surface of the diaphragm and are arranged in one direction (for example, in the X-axis direction). The plurality of piezoelectric elements are positioned on the second surface of the diaphragm so as to overlap with the plurality of pressure chambers in a plan view. The sealing member is a frame-shaped sealing member and is positioned on the second surface of the diaphragm so as to surround the plurality of piezoelectric elements in a plan view. As a result, the liquid discharge head according to the embodiment can be made smaller in the planar direction of the liquid discharge head. 【0069】 Furthermore, the liquid discharge head according to the embodiment may further include a flow channel member (e.g., flow channel member 26) having a flow channel (e.g., flow channel 26a) that penetrates in the thickness direction, joined to the second surface of the diaphragm via a sealing member. The diaphragm may have through-hole openings (e.g., opening 21c) at positions corresponding to the flow channels on the second surface that connect the flow channels to each pressure chamber. The sealing member may have a sealing portion (e.g., sealing portion 251) positioned between the second surface of the diaphragm and the flow channel member so as to surround the periphery of the flow channel and opening in a plan view. As a result, according to the liquid discharge head according to the embodiment, the sealing of multiple piezoelectric elements and the sealing of the periphery of the flow channel and opening are performed collectively by a single sealing member, thereby promoting miniaturization of the liquid discharge head in the planar direction. 【0070】 Furthermore, the sealing member may be formed in the shape of a rectangular frame including a long side and a short side in a plan view. The width of at least a portion of the long side of the sealing member (for example, the width W1 including the sealing portion) may be greater than the width of the short side of the sealing member (for example, the width W2). As a result, according to the liquid discharge head of the embodiment, even when thermal stress caused by the difference in thermal expansion coefficients between the sealing member and the diaphragm is applied more strongly to the long side of the sealing member than to the short side, the occurrence of damage to the long side of the sealing member is reduced. Therefore, the reliability of the connection by the sealing member is improved. 【0071】 Furthermore, the corners of the sealing member, which is formed in a rectangular frame shape, may be rounded. As a result, according to the liquid discharge head of this embodiment, the concentration of thermal stress at the corners caused by the difference in thermal expansion coefficients between the sealing member and the diaphragm can be mitigated, thereby reducing the occurrence of damage at the corners of the sealing member. Therefore, the reliability of the connection by the sealing member is improved. 【0072】 Furthermore, the sealing member may be made of metal. The metal may be gold (Au) or an alloy containing gold (Au). As a result, according to the liquid discharge head of the embodiment, the resistance of the sealing member to the liquid supplied into each pressure chamber is improved, and the reliability of the connection by the sealing member is further improved. 【0073】 Furthermore, the sealing member may be electrically connected to the ground electrode. As a result, according to the liquid discharge head of this embodiment, the charge accumulated on the sealing member is released to the ground electrode, thereby reducing the aggregation of components in the liquid against the sealing member. 【0074】 Furthermore, the sealing member may be formed from benzocyclobutene resin. This allows the liquid dispensing head according to the embodiment to form and seal the sealing member at a lower temperature compared to the case where metal is used, thereby reducing the thermal load on the piezoelectric element. This is advantageous for maintaining the desired element characteristics of the piezoelectric element after sealing. 【0075】 Further effects and alternative embodiments can be readily derived by those skilled in the art. Therefore, broader aspects of this disclosure are not limited to the specific details and representative embodiments expressed and described above. Accordingly, various modifications are possible without departing from the spirit or scope of the overall concept of the invention as defined by the appended claims and their equivalents. [Explanation of symbols] 【0076】 1. Printer (recording device) 8 liquid dispensing heads 14 Control Unit 22 Pressure chamber 24 Piezoelectric elements 25 Sealing member 26 Flow channel members 26a Flow channel 251 Sealing part G Ground electrode

Claims

[Claim 1] A diaphragm having a first surface and a second surface located opposite to the first surface, A plurality of pressure chambers facing the first surface and arranged in a line in one direction, A plurality of piezoelectric elements are positioned on the second surface such that they overlap with the plurality of pressure chambers in a plan view, A frame-shaped sealing member positioned on the second surface so as to surround the plurality of piezoelectric elements in a plan view, A flow channel member having a plurality of channels penetrating in the thickness direction, which is joined to the second surface via the sealing member, Equipped with, The diaphragm has through-holes at positions on the second surface corresponding to the flow channels, connecting each of the flow channels and each of the pressure chambers. The sealing member is a liquid discharge head having a sealing portion positioned between the second surface and the flow path member so as to surround the periphery of the opening in a plan view. [Claim 2] The sealing member is formed in a rectangular frame shape including a long side and a short side when viewed from above. The liquid dispensing head according to claim 1, wherein the width of at least a portion of the long side of the sealing member is greater than the width of the short side of the sealing member. [Claim 3] The sealing member is formed in a rectangular frame shape including a long side and a short side when viewed from above. The liquid dispensing head according to claim 1, wherein the corners of the sealing member are rounded. [Claim 4] The liquid dispensing head according to claim 1, wherein the sealing member is made of metal. [Claim 5] The liquid dispensing head according to claim 4, wherein the metal is gold (Au) or an alloy containing gold (Au). [Claim 6] The liquid dispensing head according to claim 4, wherein the sealing member is electrically connected to the ground electrode. [Claim 7] The liquid dispensing head according to claim 1, wherein the sealing member is formed of benzocyclobutene resin. [Claim 8] A recording device comprising a liquid dispensing head according to any one of claims 1 to 7. [Claim 9] The sealing member includes a long side portion and a short edge portion in a plan view. The aforementioned long side portion includes the sealing portion. The liquid dispensing head according to claim 1. [Claim 10] When viewed from above, the sealing member overlaps with both ends of the pressure chamber in the longitudinal direction. The liquid dispensing head according to claim 1. [Claim 11] The flow channel member has a recess with an opening on the surface facing the second surface, The plurality of piezoelectric elements are located between the recess and the plurality of pressure chambers. The liquid dispensing head according to claim 1. [Claim 12] At least some of the plurality of piezoelectric elements are housed in the recess. The liquid dispensing head according to claim 11.

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