Liquid ejection head and recording apparatus

Abstract

To promote reduction in size.SOLUTION: A liquid discharge head includes a discharge member having a first surface for discharging a liquid and a second surface positioned on a side opposite to the first surface, and a plurality of piezoelectric elements positioned on the second surface. The discharge member includes a plurality of individual electrodes, a common electrode, an individual terminal arrangement part, and a common terminal. The plurality of individual electrodes are positioned on the second surface, and are connected to each of the plurality of piezoelectric elements. The common electrode is positioned on the second surface, and is commonly connected to the plurality of piezoelectric elements. The individual terminal arrangement part arranges a plurality of individual terminals connected to each of the plurality of individual electrodes side by side in a first direction, on the second surface. The common terminal is drawn from the common electrode on the second surface, and is positioned so as to be adjacent to the individual terminal arrangement part in a second direction crossing the first direction.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The disclosed embodiments relate to a liquid ejection head and a recording apparatus. [Background technology]

[0002] 2. Description of the Related Art Known printing devices include inkjet printers and inkjet plotters that use an inkjet recording method. Such inkjet printing devices are equipped with a liquid ejection head for ejecting liquid.

[0003] Such a liquid ejection head has, for example, a plurality of piezoelectric elements on the upper surface of an ejection member that ejects liquid from the lower surface. A plurality of individual electrodes are connected to the plurality of piezoelectric elements, respectively, for supplying drive signals to the plurality of piezoelectric elements. The plurality of individual electrodes are respectively connected to a plurality of individual terminals that are arranged in a line on the upper surface of the ejection member in the longitudinal direction of the ejection member. In addition, a common electrode that supplies a reference potential is commonly connected to the plurality of piezoelectric elements. The common terminal drawn from the common electrode is located adjacent to the area on the upper surface of the ejection member where the plurality of individual terminals are arranged in the longitudinal direction of the ejection member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-142075 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned liquid ejection head, for example, if the spacing between adjacent individual terminals is increased, the position of the common terminal will shift outward in the longitudinal direction of the ejection member, increasing the longitudinal size of the ejection member, which may hinder miniaturization.

[0006] One aspect of the embodiment has been made in view of the above, and aims to provide a liquid ejection head and a recording apparatus that can facilitate miniaturization. [Means for solving the problem]

[0007] A liquid ejection head according to one aspect of the embodiment includes an ejection member having a first surface for ejecting liquid and a second surface located opposite the first surface, and a plurality of piezoelectric elements located on the second surface. The ejection member includes a plurality of individual electrodes, a common electrode, an individual terminal arrangement section, and a common terminal. The plurality of individual electrodes are located on the second surface and connected to the plurality of piezoelectric elements, respectively. The common electrode is located on the second surface and commonly connected to the plurality of piezoelectric elements. The individual terminal arrangement section arranges a plurality of individual terminals connected to the plurality of individual electrodes respectively, aligned in a first direction on the second surface. The common terminal is drawn out from the common electrode on the second surface and located adjacent to the individual terminal arrangement section in a second direction intersecting the first direction. [Effects of the Invention]

[0008] According to one aspect of the embodiment, miniaturization can be promoted. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front view that schematically shows the front of a printer according to an embodiment. [Figure 2] FIG. 2 is a plan view that schematically shows a general plane of the printer according to the embodiment. [Figure 3] FIG. 3 is a schematic side view showing the internal configuration of the liquid ejection head according to the embodiment. [Figure 4] FIG. 4 is an enlarged cross-sectional view showing a connection portion between the discharge member and the flexible substrate according to the embodiment. [Figure 5] FIG. 5 is a plan view schematically showing the discharge member according to the embodiment. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI shown in FIG. [Figure 7]FIG. 7 is a cross-sectional view taken along line VII-VII shown in FIG. [Figure 8] FIG. 8 is a plan view schematically showing a flexible substrate according to an embodiment. [Figure 9] FIG. 9 is a plan view schematically showing a discharge member according to another embodiment 1. As shown in FIG. [Figure 10] FIG. 10 is a plan view schematically showing a discharge member according to another embodiment 2. As shown in FIG. [Figure 11] FIG. 11 is a cross-sectional view taken along line XI-XI shown in FIG. [Figure 12] FIG. 12 is a plan view schematically showing a discharge member according to another embodiment 3. As shown in FIG. [Figure 13] FIG. 13 is a cross-sectional view taken along line XIII-XIII shown in FIG. [Figure 14] FIG. 14 is a cross-sectional view taken along line XIV-XIV shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of a liquid ejection head and a recording apparatus disclosed in the present application will be described with reference to the accompanying drawings. Note that the present disclosure is not limited to the embodiments described below. It should be noted that the drawings are schematic, and the dimensional relationships and ratios of elements may differ from reality. Furthermore, the dimensional relationships and ratios may differ between the drawings.

[0011] Furthermore, in the following embodiments, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not necessarily mean "constant," "orthogonal," "perpendicular," or "parallel" in the strict sense. In other words, the above expressions allow for deviations due to, for example, manufacturing precision, installation precision, etc.

[0012] Furthermore, the embodiments can be combined as appropriate within the scope of not causing any contradiction in the processing content. Furthermore, the same components in the following embodiments are denoted by the same reference numerals, and redundant explanations will be omitted.

[0013] <Printer configuration> An overview of a printer 1, which is an example of a recording apparatus according to an embodiment, will be described using Figures 1 and 2. Figure 1 is a front view that schematically shows the general front surface of the printer 1 according to an embodiment. Figure 2 is a plan view that schematically shows the general plane of the printer 1 according to an embodiment. The printer 1 according to an embodiment is, for example, a color inkjet printer.

[0014] As shown in FIG. 1, the printer 1 includes a paper feed roller 2, a guide roller 3, an applicator 4, a head case 5, a plurality of conveying rollers 6, a plurality of frames 7, a plurality of liquid ejection heads 8, a conveying roller 9, a dryer 10, a conveying roller 11, a sensor unit 12, and a recovery roller 13.

[0015] Furthermore, the printer 1 has a control unit 14 that controls each part of the printer 1. The control unit 14 controls the operations of the paper feed roller 2, the guide roller 3, the coater 4, the head case 5, the plurality of conveying rollers 6, the plurality of frames 7, the plurality of liquid ejection heads 8, the conveying roller 9, the dryer 10, the conveying roller 11, the sensor unit 12, and the recovery roller 13.

[0016] Printer 1 records images and characters on printing paper P by causing droplets to land on the printing paper P. Before use, printing paper P is wound around paper feed roller 2 in a state where it can be pulled out. Printer 1 transports printing paper P from paper feed roller 2 through guide roller 3 and coater 4 into head case 5.

[0017] The coater 4 applies the coating agent evenly to the printing paper P. This allows the surface of the printing paper P to be treated, thereby improving the printing quality of the printer 1.

[0018] The head case 5 houses a plurality of transport rollers 6, a plurality of frames 7, and a plurality of liquid ejection heads 8. Inside the head case 5, a space is formed that is isolated from the outside, except for some parts that are connected to the outside, such as the part where the printing paper P enters and leaves.

[0019] At least one of the control factors such as temperature, humidity, and air pressure of the internal space of the head case 5 is controlled by the control unit 14 as necessary. The transport rollers 6 transport the printing paper P inside the head case 5 to the vicinity of the liquid ejection head 8.

[0020] The frame 7 is a rectangular flat plate, and is positioned above and in close proximity to the print paper P being transported by the transport rollers 6. As shown in FIG. 2, the frame 7 is positioned so that its longitudinal direction is perpendicular to the transport direction of the print paper P. Inside the head case 5, multiple (for example, four) frames 7 are positioned at predetermined intervals along the transport direction of the print paper P.

[0021] A liquid, such as ink, is supplied from a liquid tank (not shown) to the liquid ejection head 8. The liquid ejection head 8 ejects the liquid supplied from the liquid tank.

[0022] The control unit 14 controls the liquid ejection head 8 based on data such as images and characters, and ejects liquid 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.

[0023] The liquid ejection head 8 is fixed to the frame 7. The liquid ejection head 8 is positioned so that its longitudinal direction is perpendicular to the direction in which the printing paper P is transported.

[0024] 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 also be a so-called serial printer.

[0025] A serial printer is a printer that alternates between recording by moving the liquid ejection head 8 back and forth in a direction that intersects with the transport direction of the printing paper P, for example, in a direction that is approximately perpendicular to the direction, and transporting the printing paper P.

[0026] As shown in Fig. 2, a plurality of (for example, five) liquid ejection heads 8 are provided on one frame 7. Fig. 2 shows an example in which three liquid ejection heads 8 are positioned in front and two in the rear in the transport direction of the printing paper P, and the liquid ejection heads 8 are positioned in the transport direction of the printing paper P so that the centers of the liquid ejection heads 8 do not overlap.

[0027] A head group 8A is made up of multiple liquid ejection heads 8 mounted on one frame 7. The four head groups 8A are positioned along the transport direction of the printing paper P. The same color ink is supplied to the liquid ejection heads 8 belonging to the same head group 8A. This allows the printer 1 to print using four colors of ink using the four head groups 8A.

[0028] The colors of ink ejected from each liquid ejection head 8 are, for example, magenta (M), yellow (Y), cyan (C), and black (K). The control unit 14 controls each liquid ejection head 8 to eject ink of multiple colors onto the printing paper P, thereby printing a color image on the printing paper P.

[0029] In order to treat the surface of the printing paper P, a coating agent may be ejected onto the printing paper P from the liquid ejection head 8.

[0030] Furthermore, the number of liquid ejection heads 8 included in one head group 8A and the number of head groups 8A mounted on the printer 1 can be changed as appropriate depending on the object to be printed and the printing conditions. For example, if a single color is printed on the printing paper P and the printing range is to be printed with one liquid ejection head 8, the number of liquid ejection heads 8 mounted on the printer 1 may be one.

[0031] The printing paper P that has been printed inside the head case 5 is transported to the outside of the head case 5 by transport rollers 9 and passes through the inside of the dryer 10. The dryer 10 dries the printing paper P that has been printed. The printing paper P that has been dried in the dryer 10 is transported by transport rollers 11 and collected by collection rollers 13.

[0032] In the printer 1, by drying the printing paper P in the dryer 10, it is possible to prevent the printing paper P that is wound up in a pile on the collection roller 13 from sticking together and preventing the undried liquid from rubbing against each other.

[0033] The sensor unit 12 is composed of a position sensor, a speed sensor, a temperature sensor, etc. The control unit 14 can determine the state of each part of the printer 1 based on information from the sensor unit 12 and control each part of the printer 1.

[0034] The printer 1 described so far has been shown to use printing paper P as the printing object (i.e., recording medium), but the printing object in printer 1 is not limited to printing paper P, and the printing object may also be a roll of cloth, etc.

[0035] Furthermore, the printer 1 may transport the printing paper P on a conveyor belt instead of directly transporting the printing paper P. By using a conveyor belt, the printer 1 can print on sheets of paper, cut pieces of cloth, wood, tiles, and the like.

[0036] The printer 1 may also be configured to eject a liquid containing conductive particles from the liquid ejection head 8 to print wiring patterns for electronic devices.

[0037] The printer 1 may also produce chemicals by ejecting a predetermined amount of liquid chemicals or liquid containing chemicals from the liquid ejection head 8 toward a reaction vessel or the like.

[0038] The printer 1 may also include a cleaning unit that cleans the liquid ejection head 8. The cleaning unit cleans the liquid ejection head 8 by, for example, wiping or capping.

[0039] The wiping process is a process of removing liquid adhering to the liquid ejection head 8, for example, by wiping the surface of the area where the liquid is ejected, such as the first surface 20A of the liquid ejection head 8 (see Figure 3), with a flexible wiper.

[0040] The capping process is performed, for example, as follows: First, a cap is placed over the surface of the portion from which the liquid is ejected, for example, the first surface 20A of the liquid ejection head 8 (this is called capping). As a result, a substantially sealed space is formed between the portion from which the liquid is ejected and the cap.

[0041] Next, the liquid is repeatedly ejected from this sealed space, which allows the removal of liquids with higher viscosity than normal or foreign matter that may have clogged the ejection holes (nozzles) that eject the liquid.

[0042] <Configuration of liquid ejection head> Next, the configuration of the liquid ejection head 8 according to this embodiment will be described with reference to Fig. 3. Fig. 3 is a schematic side view showing the internal configuration of the liquid ejection head 8 according to this embodiment. Fig. 3 shows a side surface perpendicular to the longitudinal direction of the liquid ejection head 8.

[0043] For ease of understanding, FIG. 3 illustrates a three-dimensional Cartesian coordinate system including a Z-axis whose positive direction is the vertically upward direction. This Cartesian coordinate system may also be shown in other drawings used in the following description. For convenience, in the following description, the direction in which the first surface 20A of the liquid ejection head 8 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." The Y-axis direction corresponds to the longitudinal direction of the liquid ejection head 8, and the X-axis direction corresponds to the lateral direction of the liquid ejection head 8.

[0044] The liquid ejection head 8 includes an ejection member 20, a plurality of piezoelectric elements 30, a support substrate 40, a liquid supply member (not shown), a flexible substrate 50, and a driving IC 60. The ejection member 20, the plurality of piezoelectric elements 30, the support substrate 40, the liquid supply member (not shown), the flexible substrate 50, and the driving IC 60 are housed in a housing (not shown).

[0045] The discharge member 20 has a generally flat plate shape and has a first surface 20A from which liquid is discharged and a second surface 20B located on the opposite side of the first surface 20A. The second surface 20B has openings (not shown), and liquid is supplied to the interior of the discharge member 20 from a support substrate 40 (described below) through these openings. The second surface 20B has a plurality of discharge holes that discharge liquid onto the printing paper P. A flow path is located inside the discharge member 20, which allows liquid to flow from the second surface 20B to the first surface 20A. The flow path of the discharge member 20 has a plurality of pressure chambers that are respectively connected to the plurality of discharge holes.

[0046] The plurality of piezoelectric elements 30 are located on the second surface 20B of the discharge member 20. The plurality of piezoelectric elements 30 are located so as to overlap with each pressure chamber of the discharge member 20 in a plan view. The piezoelectric elements 30 are displaced upon receiving a drive signal, thereby changing the internal pressure of the corresponding pressure chamber.

[0047] The support substrate 40 is located on top of the discharge member 20. The support substrate 40 has a flow path therein, and supplies the liquid supplied from the liquid supply member to the discharge member 20. The support substrate 40 has a predetermined thickness that is thicker than the discharge member 20, and has the function of reinforcing the discharge member 20.

[0048] The liquid supply member is located on the support substrate 40. The liquid supply member has openings (not shown) at both ends in the main scanning direction, which is perpendicular to the sub-scanning direction, which is the transport direction of the printing paper P, and which is parallel to the printing paper P. The liquid supply member has a flow path inside, and liquid is supplied from the outside through the openings. The liquid supply member supplies liquid to the support substrate 40. The liquid supply member also stores the liquid to be supplied to the support substrate 40.

[0049] The flexible substrate 50 is a flexible wiring substrate, and has the function of transmitting drive signals and the like for the piezoelectric element 30 to the discharge member 20. As shown in FIG. 3, the liquid discharge head 8 has two flexible substrates 50. One end of the flexible substrate 50 is electrically connected to the discharge member 20, and the other end of the flexible substrate 50 is drawn out above the support substrate 40 and is electrically connected to another wiring substrate (not shown). The flexible substrate 50 has a connection surface that is connected to the discharge member 20 and an opposite surface that is located opposite the connection surface.

[0050] The driving IC 60 is mounted on the flexible substrate 50. The driving IC 60 drives the piezoelectric element 30 based on a driving signal sent from the control unit 14 (see FIG. 1). In this way, the driving IC 60 can control the driving of the liquid ejection head 8.

[0051] It should be noted that FIG. 3 shows an example of the configuration of the liquid ejection head 8, and the liquid ejection head 8 may further include members other than those shown in FIG.

[0052] <Configuration of the connection portion between the discharge member and the flexible substrate> Next, the configuration of the connection portion between the discharge member 20 and the flexible substrate 50 according to the embodiment will be described with reference to Fig. 4. Fig. 4 is an enlarged cross-sectional view showing the connection portion between the discharge member 20 and the flexible substrate 50 according to the embodiment. As shown in Fig. 4, the flexible substrate 50 is connected to the discharge member 20. A first electrode pad 27 and a plurality of second electrode pads 28 are arranged at an end of the discharge member 20. In addition, a common wiring 51 and a plurality of individual wirings 52 are arranged at an end of the flexible substrate 50.

[0053] The common wiring 51 of the flexible substrate 50 is bonded to the first electrode pad 27 of the discharge member 20. Furthermore, the multiple individual wirings 52 of the flexible substrate 50 are bonded to the multiple second electrode pads 28 of the discharge member 20, respectively. The common wiring 51 and the first electrode pad 27, and the individual wirings 52 and the second electrode pads 28 are bonded together by a conductive bonding material. For example, an anisotropic conductive film (ACF) can be used as this conductive bonding material.

[0054] <Configuration of the Discharge Member> Next, the configuration of the discharge member 20 according to the embodiment will be described with reference to Fig. 5 to Fig. 7. Fig. 5 is a plan view schematically showing the discharge member 20 according to the embodiment. Fig. 6 is a cross-sectional view taken along line VI-VI shown in Fig. 5. Fig. 7 is a cross-sectional view taken along line VII-VII shown in Fig. 5.

[0055] 5 is a diagram showing the configuration of the connection portion of the discharge member 20 with the flexible substrate 50, as viewed from the second surface 20B side. A plurality of piezoelectric elements 30 (see FIG. 3) are located on this second surface 20B.

[0056] As shown in FIG. 5, the ejection member 20 includes a plurality of individual electrodes 21, a common electrode 22, an individual terminal arrangement portion 24, and a common terminal 25.

[0057] The plurality of individual electrodes 21 are located on the second surface 20B. The plurality of individual electrodes 21 are electrically connected to the plurality of piezoelectric elements 30 (not shown in FIG. 5, see FIG. 3), respectively, and extend toward the individual terminal arrangement portion 24. The individual electrodes 21 are electrodes for supplying drive signals to the piezoelectric elements 30. The plurality of individual electrodes 21 have a plurality of linear portions 21a connected to the plurality of piezoelectric elements 30, respectively, and tapered portions 21b connected to the linear portions 21a, respectively, and reaching the plurality of individual terminals 23.

[0058] The common electrode 22 is located on the second surface 20B. The common electrode 22 is electrically connected in common to the plurality of piezoelectric elements 30 and extends in the X-axis direction. The common electrode 22 is an electrode for supplying a reference potential (ground potential) to the piezoelectric elements 30.

[0059] The individual terminal arrangement section 24 is configured by arranging a plurality of individual terminals 23 connected to the plurality of individual electrodes 21, respectively, side by side in the Y-axis direction (the longitudinal direction of the liquid ejection head 8) on the second surface 20B. The Y-axis direction is an example of a first direction. The plurality of individual terminals 23 have a larger pitch (spacing) than the plurality of individual electrodes 21. The individual terminal arrangement section 24 is located at a position closer to the periphery of the second surface 20B in the X-axis direction than the plurality of individual electrodes 21 and the common electrode 22.

[0060] The common terminal 25 is drawn out from the common electrode 22 on the second surface 20B and is positioned adjacent to the individual terminal arrangement section 24 in the X-axis direction (the short-side direction of the liquid ejection head 8). The X-axis direction is an example of a second direction. Since the common terminal 25 is positioned adjacent to the individual terminal arrangement section 24 in the X-axis direction, even if the interval between adjacent individual terminals 23 increases, the position of the common terminal 25 will not shift in the Y-axis direction. This does not change the size of the ejection member 20 in the Y-axis direction, which can facilitate miniaturization of the liquid ejection head 8.

[0061] Furthermore, the common terminal 25 is positioned adjacent to the plurality of individual electrodes 21 in the Y-axis direction (longitudinal direction of the liquid ejection head 8). By positioning the common terminal 25 adjacent to the plurality of individual electrodes 21 in the Y-axis direction, it is possible to realize a layout of the common terminal 25 that effectively utilizes the space adjacent to the plurality of individual electrodes 21, which has a smaller pitch (spacing) than the plurality of individual terminals 23. This further facilitates miniaturization of the liquid ejection head 8.

[0062] As shown in FIGS. 5 and 6, the ejection member 20 further includes an insulating film 26 and a first electrode pad 27.

[0063] The insulating film 26 is located on the second surface 20B so as to cover the individual electrodes 21 and the common electrode 22. The insulating film 26 has a first opening 26a at a position overlapping the common terminal 25. The insulating film 26 also has a second opening 26b (see FIG. 7) at a position overlapping the individual terminals 23.

[0064] The first electrode pad 27 is located on the insulating film 26. The first electrode pad 27 is electrically connected to the common terminal 25 through the first opening 26a. This allows the area of ​​the conductive portion of the common terminal 25 to be increased by the area of ​​the first electrode pad 27, thereby reducing the electrical resistance of the common terminal 25.

[0065] Furthermore, the first electrode pads 27 extend in the Y-axis direction (the longitudinal direction of the liquid ejection head 8) on the insulating film 26. This increases the bonding strength between the first electrode pads 27 and the common wiring 51 of the flexible substrate 50, thereby improving the connection reliability between the ejection member 20 and the flexible substrate 50.

[0066] The first electrode pad 27 extends over an area on the insulating film 26 that corresponds to the tapered portions 21b of the individual electrodes 21.

[0067] As shown in FIGS. 5 and 7, the discharge member 20 further includes a plurality of second electrode pads .

[0068] The second electrode pads 28 are located in the second openings 26b of the insulating film 26 and are electrically connected to the individual terminals 23, respectively. The second electrode pads 28 protrude from the second openings 26b. The height of the second electrode pads 28 relative to the upper surface of the insulating film 26 is substantially the same as the height of the first electrode pads 27 relative to the upper surface of the insulating film 26. By connecting the second electrode pads 28 to the individual terminals 23, the area of ​​the conductive portion of the individual terminals 23 can be increased by the area of ​​the second electrode pads 28, and therefore the electrical resistance of the individual terminals 23 can be reduced.

[0069] Furthermore, a portion of the insulating film 26 is located between adjacent second electrode pads 28. This reduces problems caused by ion migration between adjacent second electrode pads 28. Ion migration is a phenomenon in which metal on the anode side is ionized by an electric field caused by current flow, and the ionized metal migrates to the cathode, where it is regenerated as metal. If the insulating film 26 were not present between adjacent second electrode pads 28, moisture would easily penetrate, promoting the movement of metal due to the electric field and making ion migration more likely to occur. In contrast, by having a portion of the insulating film 26 located between adjacent second electrode pads 28, moisture penetration can be reduced compared to when the insulating film 26 is not present between adjacent second electrode pads 28, and as a result, problems caused by ion migration can be reduced.

[0070] <Configuration of flexible substrate 50> Next, the configuration of the flexible substrate 50 according to the embodiment will be described with reference to Fig. 8. Fig. 8 is a plan view schematically showing the flexible substrate 50 according to the embodiment.

[0071] 8 is a diagram showing the configuration of the connection portion of the flexible substrate 50 with the discharge member 20, as viewed from the opposite side of the connection surface. In FIG. 8, each element on the connection surface side of the flexible substrate 50 is shown by a hatched area.

[0072] 8, the flexible substrate 50 has a common wiring 51 corresponding to the common terminal 25 of the discharge member 20, and a plurality of individual wirings 52 corresponding to the plurality of individual terminals 23. The common wiring 51 is bonded to a first electrode pad 27 connected to the common terminal 25. The plurality of individual wirings 52 are bonded to a plurality of second electrode pads 28 connected to the plurality of individual terminals 23, respectively.

[0073] The common wiring 51 has a first portion 51a extending in the Y-axis direction (the longitudinal direction of the liquid ejection head 8). This reinforces the flexible substrate 50 in the Y-axis direction, thereby reducing the risk of damage to the flexible substrate 50 due to thermal expansion and contraction.

[0074] The common wiring 51 also has a second portion 51b that is connected to the first portion 51a and extends in the X-axis direction (the short-side direction of the liquid ejection head 8). The area of ​​the flexible substrate 50 where the multiple individual wirings 52 are located is surrounded by the first portion 51a and the second portion 51b. This allows the multiple individual wirings 52 to be protected by the common wiring 51, thereby reducing the risk of the individual wirings 52 being broken.

[0075] <Another embodiment> Fig. 9 is a plan view schematically showing a discharge member 20 according to another embodiment 1. As shown in Fig. 9, the first electrode pad 27 may extend to a position on the insulating film 26 closer to the piezoelectric element 30 (i.e., the upper side in Fig. 9) than the connection portion between the plurality of linear portions 21a and the plurality of tapered portions 21b. This allows the area of ​​the conductive portion of the common terminal 25 to be further enlarged by the area of ​​the first electrode pad 27, thereby further reducing the electrical resistance of the common terminal 25.

[0076] Fig. 10 is a plan view schematically showing an ejection member 20 according to another embodiment 2. Fig. 11 is a cross-sectional view taken along line XI-XI shown in Fig. 10. The ejection member 20 shown in Fig. 10 has an additional common electrode 29 between adjacent individual electrodes 21. The additional common electrode 29 extends to a position farther from the piezoelectric element 30 side (i.e., the upper side in Fig. 9) than the connection portion between the linear portion 21a and the tapered portion 21b of the individual electrode 21. A portion of the additional common electrode 29 is located at a position overlapping with the first electrode pad 27 in a plan view.

[0077] 11, the additional common electrode 29 penetrates the insulating film 26 and is electrically connected to the first electrode pad 27. This allows the area of ​​the first electrode pad 27 to be increased by the area of ​​the additional common electrode 29, thereby reducing the electrical resistance of the first electrode pad 27.

[0078] FIG. 12 is a plan view schematically showing a discharge member 20 according to another embodiment 3. FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 12. FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 12. As shown in FIGS. 12 to 14, the discharge member 20 according to another embodiment 3 differs from the discharge member 20 shown in FIGS. 5 to 7 in that the discharge member 20 does not have a first electrode pad 27 or a second electrode pad 28. That is, in the discharge member 20 according to another embodiment 3, the first electrode pad 27 is not located on the insulating film 26, and therefore the common terminal 25 is exposed from the first opening 26a of the insulating film 26. Furthermore, the second electrode pad 28 is not located in the second opening 26b of the insulating film 26, and therefore the individual terminal 23 is exposed from the second opening 26b.

[0079] When the flexible substrate 50 is connected to the discharge member 20, the common wiring 51 of the flexible substrate 50 is directly bonded to the common terminal 25 of the discharge member 20. Furthermore, the multiple individual wirings 52 of the flexible substrate 50 are bonded to the multiple individual terminals 23 of the discharge member 20, respectively. The common wiring 51 and the common terminal 25, and the individual wirings 52 and the individual terminals 23 are bonded together with a conductive bonding material. For example, an anisotropic conductive film (ACF) can be used as this conductive bonding material. In this way, the discharge member 20 does not have the first electrode pad 27 and the second electrode pad 28, thereby simplifying the configuration of the discharge member 20.

[0080] As described above, a liquid ejection head according to an embodiment (e.g., liquid ejection head 8) includes an ejection member (e.g., ejection member 20) having a first surface (e.g., first surface 20A) for ejecting liquid and a second surface (e.g., second surface 20B) located opposite the first surface, and a plurality of piezoelectric elements (e.g., piezoelectric elements 30) located on the second surface. The ejection member includes a plurality of individual electrodes (e.g., individual electrode 21), a common electrode (e.g., common electrode 22), an individual terminal arrangement section (e.g., individual terminal arrangement section 24), and a common terminal (e.g., common terminal 25). The plurality of individual electrodes are located on the second surface and are connected to the plurality of piezoelectric elements, respectively. The common electrode is located on the second surface and is commonly connected to the plurality of piezoelectric elements. The individual terminal arrangement section arranges a plurality of individual terminals (e.g., individual terminal 23) connected to the plurality of individual electrodes, arranged in a first direction (e.g., the Y-axis direction) on the second surface. The common terminal is drawn out from the common electrode on the second surface and is positioned adjacent to the individual terminal arrangement portion in a second direction (e.g., the X-axis direction) that intersects with the first direction, thereby facilitating miniaturization of the liquid ejection head according to the embodiment.

[0081] The common terminal may be positioned adjacent to the individual electrodes in the first direction, which makes it possible to further reduce the size of the liquid ejection head according to the embodiment.

[0082] The ejection member may further include an insulating film (e.g., insulating film 26) and a first electrode pad (e.g., first electrode pad 27). The insulating film may be located on the second surface so as to cover the plurality of individual electrodes and the common electrode, and may have a first opening (e.g., first opening 26a) at a position overlapping with the common terminal. The first electrode pad may be located on the insulating film and connected to the common terminal via the first opening. This allows the liquid ejection head according to the embodiment to reduce the electrical resistance of the common terminal.

[0083] Furthermore, the first electrode pads may extend in the first direction on the insulating film, which improves the connection reliability between the discharge member and the flexible substrate (for example, the flexible substrate 50) in the liquid discharge head according to the embodiment.

[0084] The insulating film may also have second openings (e.g., second openings 26b) at positions overlapping the individual terminals. The ejection member may further include a plurality of second electrode pads (e.g., second electrode pads 28) located in the second openings, connected to the individual terminals, and protruding from the second openings. A portion of the insulating film may be located between adjacent second electrode pads. This allows the liquid ejection head according to the embodiment to reduce problems caused by ion migration between adjacent second electrode pads.

[0085] Furthermore, the liquid ejection head according to the embodiment may further include a wiring substrate (e.g., flexible substrate 50) having a common wiring (e.g., common wiring 51) corresponding to the common terminal and a plurality of individual wirings (e.g., individual wirings 52) corresponding to the plurality of individual terminals. The common wiring may have a first portion (e.g., first portion 51a) extending in a first direction. This makes it possible for the liquid ejection head according to the embodiment to reduce the risk of damage to the wiring substrate due to thermal expansion and thermal contraction.

[0086] The common wiring may have a second portion (e.g., second portion 51b) that is connected to the first portion and extends in the second direction, and the region of the wiring board where the individual wirings are located may be surrounded by the first portion and the second portion. This allows the liquid ejection head according to the embodiment to reduce the risk of disconnection of the individual wirings.

[0087] Further advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0088] 1. Printer 8 Liquid ejection head 20 Discharge member 20A Page 1 20B 2nd side 21 individual electrodes 21a Straight section 21b Tapered portion 22 Common electrode 23 individual terminals 24 Individual terminal arrangement section 25 Common terminal 26 insulating film 26a 1st opening 26b 2nd opening 27 First electrode pad 28 Second electrode pad 29 Additional common electrode 30 Piezoelectric element 40 Support Board 50 Flexible PCB 51 Common wiring 51a Part 1 51b Part 2 52 Individual wiring

Claims

1. a discharge member having a first surface for discharging a liquid and a second surface located opposite to the first surface; a plurality of piezoelectric elements located on the second surface; Equipped with The discharge member is a plurality of individual electrodes located on the second surface and connected to the plurality of piezoelectric elements, respectively; a common electrode located on the second surface and connected in common to the plurality of piezoelectric elements; an individual terminal arrangement portion on the second surface, in which a plurality of individual terminals connected to the plurality of individual electrodes are arranged in a first direction; a common terminal that is drawn from the common electrode on the second surface and is positioned adjacent to the individual terminal arrangement portion in a direction in which the plurality of piezoelectric elements are arranged in a second direction intersecting the first direction; Equipped with The common terminal is positioned adjacent to the plurality of individual electrodes in the first direction, and is not positioned between the plurality of individual electrodes. Liquid ejection head.

2. The discharge member is an insulating film located on the second surface so as to cover the plurality of individual electrodes and the common electrode, the insulating film having a first opening at a position overlapping the common terminal; a first electrode pad located on the insulating film and connected to the common terminal through the first opening; The liquid ejection head according to claim 1 , further comprising:

3. The liquid ejection head according to claim 2 , wherein the first electrode pad extends in the first direction on the insulating film.

4. the insulating film has second openings at positions overlapping the plurality of individual terminals; The discharge member is a plurality of second electrode pads located in the second opening, connected to the plurality of individual terminals respectively, and protruding from the second opening; 3. The liquid ejection head according to claim 2, wherein a part of the insulating film is located between adjacent second electrode pads.

5. a wiring substrate having a common wiring corresponding to the common terminal and a plurality of individual wirings corresponding to the plurality of individual terminals; The liquid ejection head according to claim 1 , wherein the common wiring has a first portion extending in the first direction.

6. the common wiring has a second portion connected to the first portion and extending in the second direction; The liquid ejection head according to claim 5 , wherein an area of ​​the wiring board where the plurality of individual wirings are located is surrounded by the first portion and the second portion.

7. A recording apparatus comprising the liquid ejection head according to any one of claims 1 to 6.

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