Liquid dispensing head and liquid dispensing device

Abstract

To suppresses variations in voltage supplied to piezoelectric elements.SOLUTION: A liquid ejecting head includes a line of first pressure chambers, a line of second pressure chambers, a line of nozzles including nozzles arranged in a first direction, first piezoelectric bodies, first individual electrodes, a first common electrode, second piezoelectric bodies, second individual electrodes, a second common electrode, a wiring member, a first individual line that electrically couples the first individual electrode to the wiring member, a first common line that electrically couples the first common electrode to the wiring member, a second individual line that electrically couples the second individual electrode to the wiring member, and a second common line that electrically couples the second common electrode to the wiring member. The wiring member is electrically coupled to the first common line at a position shifted to one side in the first direction relative to a center in the first direction of the lines of first and second pressure chambers, and the wiring member is electrically coupled to the second common line at a position shifted to the other side in the first direction relative to the center in the first direction of the lines of first and second pressure chambers.SELECTED DRAWING: Figure 8

Description

Technical Field

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

Background Art

[0002] For example, a liquid ejection head includes a plurality of pressure chambers for storing liquid, a diaphragm formed on the pressure chambers, an actuator for driving the diaphragm, and a wiring member for supplying a signal to the actuator (see, for example, Patent Document 1). The actuator has an individual electrode provided for each of the plurality of pressure chambers, a common electrode provided commonly for the plurality of individual electrodes, and a piezoelectric body disposed between the individual electrode and the common electrode.

[0003] The liquid ejection head includes a nozzle row and a plurality of pressure chamber rows. The nozzle row includes a plurality of nozzles arranged in a predetermined direction. At least one pressure chamber is communicated with the nozzle. The pressure chamber row extends in the direction in which the nozzle row extends. The plurality of pressure chamber rows are spaced apart from each other in a direction intersecting the direction in which the nozzle row extends.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the liquid discharge head, the signal output from the drive circuit is supplied to the common electrode via the wiring board and common wiring. The common wiring extends along the first direction, which is the direction in which the pressure chamber row extends. The wiring board and the common wiring are electrically connected via a common wiring mounting section. The voltage supplied to the actuators further away from the common wiring mounting section is lower than the voltage supplied to the actuators closer to the common wiring mounting section. Specifically, since the common wiring mounting section is located at both ends of the common wiring in the first direction, a problem arises where the voltage supplied to the actuator located in the center is lower than the voltage supplied to the actuators located on the outside. Therefore, if there is a large variation in the supplied voltage among the multiple actuators arranged in the first direction, there is a risk that there will be a large variation in liquid discharge among the multiple nozzles arranged in the first direction. [Means for solving the problem]

[0006] A liquid discharge head according to one aspect of the present invention comprises: a first pressure chamber row in which a plurality of first pressure chambers are arranged in a first direction; a second pressure chamber row in which a plurality of second pressure chambers are arranged in a first direction and are provided at different positions in a second direction intersecting the first direction with the first pressure chambers; a nozzle row in which a plurality of nozzles, each communicating in common with the first and second pressure chambers, are arranged in a first direction; a first piezoelectric element provided corresponding to the plurality of first pressure chambers; a first individual electrode electrically connected to the first piezoelectric element and provided individually for the plurality of first pressure chambers; a first common electrode electrically connected to the first piezoelectric element and provided in common for the plurality of first pressure chambers; a second piezoelectric element provided corresponding to the plurality of second pressure chambers; a second individual electrode electrically connected to the second piezoelectric element and provided individually for the plurality of second pressure chambers; and the first piezoelectric element The device comprises a second common electrode electrically connected and provided in common to a plurality of first pressure chambers, a wiring member for supplying voltage to the first individual electrode, the first common electrode, the second individual electrode, and the second common electrode, a first individual wiring that electrically connects the first individual electrode and the wiring member, a first common wiring that electrically connects the first common electrode and the wiring member, a second individual wiring that electrically connects the second individual electrode and the wiring member, and a second common wiring that electrically connects the second common electrode and the wiring member. The wiring member and the first common wiring are electrically connected at a position shifted to one side along the first direction from the center in the first direction of the first and second pressure chamber rows, and the wiring member and the second common wiring are electrically connected at a position shifted to the other side along the first direction from the center in the first direction of the first and second pressure chamber rows.

[0007] A liquid discharge head according to one aspect of the present invention includes: a first pressure chamber row in which a plurality of first pressure chambers are arranged in a first direction; a second pressure chamber row in which a plurality of second pressure chambers are arranged in a first direction and provided at different positions in a second direction intersecting the first direction with respect to the first pressure chambers; a first nozzle row in which a plurality of first nozzles communicating with each of the plurality of first pressure chambers are arranged in a first direction; a second nozzle row in which a plurality of second nozzles communicating with each of the plurality of second pressure chambers are arranged in a first direction; a first piezoelectric body provided corresponding to the plurality of first pressure chambers; a first individual electrode electrically connected to the first piezoelectric body and provided individually for each of the plurality of first pressure chambers; a first common electrode electrically connected to the first piezoelectric body and provided in common for the plurality of first pressure chambers; a second piezoelectric body provided corresponding to the plurality of second pressure chambers; and a second piezoelectric body electrically connected to the second piezoelectric body and provided for each of the plurality of second pressure chambers. The device comprises individually provided second individual electrodes, a second common electrode electrically connected to a first piezoelectric element and provided in common for a plurality of first pressure chambers, a wiring member for supplying voltage to the first individual electrodes, the first common electrode, the second individual electrodes, and the second common electrode, a first individual wiring that electrically connects the first individual electrodes and the wiring member, a first common wiring that electrically connects the first common electrode and the wiring member, a second individual wiring that electrically connects the second individual electrodes and the wiring member, and a second common wiring that electrically connects the second common electrode and the wiring member. The wiring member and the first common wiring are electrically connected at a position shifted to one side along the first direction from the center of the first and second pressure chamber rows in the first direction, and the wiring member and the second common wiring are electrically connected at a position shifted to the other side along the first direction from the center of the first and second pressure chamber rows in the first direction.

[0008] A liquid dispensing device according to one aspect of the present invention comprises the above-mentioned liquid dispensing head and a control unit that controls the dispensing operation from the liquid dispensing head. [Brief explanation of the drawing]

[0009] [Figure 1] This is an exploded perspective view showing the liquid dispensing head according to Example 1. [Figure 2] This is a cross-sectional view showing the liquid dispensing head, specifically the cross-section along the line II-II in Figure 1. [Figure 3] This is a plan view showing the liquid dispensing head. [Figure 4] This is a cross-sectional view showing the cross-section along the line IV-IV in Figure 3. [Figure 5] This is a plan view showing the pressure chamber, individual electrodes, and COM wiring. [Figure 6] This is a plan view showing the common electrode and VBS wiring. [Figure 7] This is a cross-sectional view showing the cross-section along the line VII-VII in Figure 6. [Figure 8] This is a plan view showing an enlarged view of the main part of the liquid discharge head according to Example 1. [Figure 9] This is a cross-sectional view showing the cross-section along the line IX-IX in Figure 8. [Figure 10] This is a cross-sectional view showing a part of the liquid discharge head according to Example 2. [Figure 11] This is a plan view showing an enlarged view of the main part of the liquid discharge head according to Example 2. [Figure 12] This is a plan view showing an enlarged view of the main part of the liquid discharge head according to Example 3. [Figure 13] This is a plan view showing an enlarged view of the main part of the liquid discharge head according to Example 4. [Figure 14] This is a plan view showing an enlarged view of the main part of the liquid discharge head according to Example 5. [Figure 15] This is a cross-sectional view showing the pressure chamber on the A-row side of the liquid discharge head according to Example 6. [Figure 16] This is a cross-sectional view showing the pressure chamber on the B-row side of the liquid discharge head according to Example 6. [Figure 17] This is a cross-sectional view showing the liquid dispensing head according to Example 7. [Figure 18] This is a schematic diagram showing a liquid dispensing device equipped with a liquid dispensing head. [Figure 19] A block of liquid dispensing equipment equipped with a liquid dispensing head. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments for implementing the present invention will be described with reference to the drawings. However, in each figure, the dimensions and scales of each part are appropriately different from the actual ones. Further, the embodiments described below are preferred specific examples of the present invention, and thus various technically preferable limitations are imposed. However, the scope of the present invention is not limited to these embodiments unless there is a description specifically limiting the present invention in the following description.

[0011] In the following description, there may be cases where three mutually intersecting directions are described as the X-axis direction, the Y-axis direction, and the Z-axis direction. The X-axis direction includes the X1 direction and the X2 direction which are opposite to each other. The X-axis direction is an example of the second direction. The Y-axis direction includes the Y1 direction and the Y2 direction which are opposite to each other. The Y-axis direction is an example of the first direction. The Z-axis direction includes the Z1 direction and the Z2 direction which are opposite to each other. The Z1 direction is an example of the third direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are orthogonal. The Z-axis direction is usually a direction along the vertical direction, but the Z-axis direction may not be a direction along the vertical direction.

[0012] <Example 1> Referring to FIGS. 1 to 8, the liquid ejection head 10 according to Example 1 will be described. FIG. 1 is an exploded perspective view showing the liquid ejection head 10 according to the first embodiment. FIG. 2 is a cross-sectional view showing the liquid ejection head 10, and is a view showing a cross-section along the line II-II in FIG. 1. FIG. 3 is a plan view showing the liquid ejection head 10. FIG. 4 is a cross-sectional view showing a cut surface along the line IV-IV in FIG. 3. FIG. 5 is a plan view showing the pressure chamber CA, the individual electrode 51A, and the COM wiring 54A. FIG. 6 is a plan view showing the common electrode 52A and the VBS wiring 55A. The liquid ejection head 10 employs a circulation method for circulating the liquid flowing through the common liquid chambers RA, RB and the pressure chambers CA, CB.

[0013] As shown in Figure 1, the liquid discharge head 10 comprises a pressure chamber row CAL and a pressure chamber row CBL. The pressure chamber row CAL includes a plurality of pressure chambers CA arranged in the Y-axis direction. The pressure chamber row CBL includes a plurality of pressure chambers CB arranged in the Y-axis direction. Pressure chambers CA are an example of a "first pressure chamber," and pressure chambers CB are an example of a "second pressure chamber." The pressure chamber row CAL is an example of a "first pressure chamber row," and pressure chamber row CBL is an example of a "second pressure chamber row." As shown in Figures 1 and 3, the pressure chamber row CAL and the pressure chamber row CBL are spaced apart from each other in the X-axis direction. Note that while Figures 4 to 6 show the pressure chamber row CAL, the pressure chamber row CBL is similar in shape to the pressure chamber row CAL, so its illustration is omitted. Figure 3 shows some of the plurality of pressure chambers CA and CB.

[0014] Furthermore, the terms "A-row side" and "B-row side" are used in this specification. "A-row side" is used when referring to something related to the "pressure chamber row CAL," and "B-row side" is used when referring to something related to the "pressure chamber row CBL." For example, when it is written as "A-row side piezoelectric element 50A," it refers to the piezoelectric element 50A that changes the pressure of the liquid in the pressure chamber CA of the pressure chamber row CAL. When it is written as "A-row side VBS wiring 55A," it refers to the VBS wiring 55A that supplies voltage to the common electrode 52A of the piezoelectric element 50A.

[0015] Figure 3 also illustrates a center line OX that passes through the center of pressure chamber rows CAL and CBL in the Y-axis direction and extends in the X-axis direction. Pressure chamber row CAL includes pressure chambers CA0, CA1, and CA2. Pressure chamber CA0 is located in the center of the multiple pressure chambers CA in the Y-axis direction. Pressure chamber CA0 is the pressure chamber CA closest to the center line OX in the Y-axis direction. Note that if the center line OX exists between multiple pressure chambers CA, then all of the pressure chambers CA are considered to be pressure chamber CA0.

[0016] Pressure chamber CA1 is one of the multiple pressure chambers CA located at one end in the Y-axis direction. Pressure chamber CA1 is furthest from the center line OX in the Y1 direction in the Y-axis direction. Pressure chamber CA2 is one of the multiple pressure chambers CA located at the other end in the Y-axis direction in the Y-axis direction. Pressure chamber CA2 is furthest from the center line OX in the Y2 direction in the Y-axis direction.

[0017] The pressure chamber row CBL includes pressure chambers CB0, CB1, and CB2. Pressure chamber CB0 is located in the center of the multiple pressure chambers CB in the Y-axis direction. Pressure chamber CB0 is the pressure chamber CB closest to the center line OX in the Y-axis direction.

[0018] Pressure chamber CB1 is one of several pressure chambers CB located at one end in the Y-axis direction. Pressure chamber CB1 is furthest from the center line OX in the Y1 direction. Pressure chamber CA2 is one of several pressure chambers CA located at the other end in the Y-axis direction. Pressure chamber CB2 is furthest from the center line OX in the Y2 direction.

[0019] The liquid ejection head 10 comprises a nozzle plate 21, a compliance substrate 23, a communication plate 24, a pressure chamber substrate 25, a diaphragm 26, a sealing plate 27, and piezoelectric elements 50A and 50B. The liquid ejection head 10 also comprises a case 28 and a COF 60. COF is an abbreviation for Chip on Film. In this embodiment, a liquid ejection head 10 that ejects ink, which is an example of a liquid, will be described. The liquid is not limited to ink, and the liquid ejection head 10 can eject other liquids.

[0020] The thickness direction of the nozzle plate 21, compliance substrate 23, communication plate 24, pressure chamber substrate 25, diaphragm 26, sealing plate 27, and case 28 is aligned with the Z-axis direction. The nozzle plate 21 and compliance substrate 23 are located at the bottom of the liquid discharge head 10. The communication plate 24 is located in the Z2 direction of the nozzle plate 21 and compliance substrate 23. The pressure chamber substrate 25 is located in the Z2 direction of the communication plate 24. The diaphragm 26 is located in the Z2 direction of the pressure chamber substrate 25. Multiple piezoelectric elements 50A and 50B are formed on the diaphragm 26. The sealing plate 27 is located in the Z2 direction of the diaphragm 26. The sealing plate 27 covers the multiple piezoelectric elements 50. The case 28 is located on the communication plate 24. Piezoelectric element 50A is provided corresponding to pressure chamber CA. Piezoelectric element 50B is provided corresponding to pressure chamber CB. Piezoelectric element 50A may also be a "first piezoelectric element". Piezoelectric element 50B may also be referred to as the "second piezoelectric element." Furthermore, if there is no distinction between "piezoelectric element 50A" and "piezoelectric element 50B," it may be simply written as "piezoelectric element 50."

[0021] Next, the ink flow path 40 will be described. The liquid ejection head 10 has an ink flow path 40 formed therein. The flow path 40 includes a supply port 42A, an outlet port 42B, common liquid chambers RA, RB, intermediate flow paths 43A, 43B, pressure chambers CA, CB, connecting flow paths 45A to 45C, and a nozzle N.

[0022] The flow path 40 includes a plurality of individual flow paths 41. Each of the plurality of individual flow paths 41 is provided corresponding to a plurality of nozzles N. The individual flow paths 41 have individual flow paths 41A and individual flow paths 41B. Individual flow path 41A includes a relay flow path 43A, a pressure chamber CA, a connecting flow path 45A, and a part of the connecting flow path 45C. The common liquid chamber RA is in common with the plurality of individual flow paths 41A and supplies ink to the plurality of individual flow paths 41A. The common liquid chamber RA is an example of a common supply flow path. Individual flow path 41A is the portion of the individual flow path 41 upstream of the nozzles N.

[0023] The individual flow path 41B includes the relay flow path 43B, the pressure chamber CB, the communication flow path 45B, and a portion of the communication flow path 45C. The common liquid chamber RB is in common communication with multiple individual flow paths 41B. Ink is discharged into the common liquid chamber RB from multiple individual flow paths 41B. The common liquid chamber RB discharges ink from multiple individual flow paths 41B. The common liquid chamber RB is an example of a common discharge flow path.

[0024] The liquid ejection head 10 employs a circulation system in which the ink that has flowed through pressure chambers CA and CB is circulated. As shown in Figure 18, the liquid ejection head 10 is connected to a circulation mechanism 8 for circulating the ink. The circulation mechanism 8 is connected to a liquid container 2. The circulation mechanism 8 includes a supply channel 81 for supplying ink to the liquid ejection head 10, a recovery channel 82 for recovering the ink discharged from the liquid ejection head 10, and a pump 83 for transferring the ink. The supply channel 81 and the recovery channel 82 may be, for example, channels inside a tube. The supply channel 81 and the recovery channel 82 include channels formed by openings, grooves, recesses, etc.

[0025] The ink in the liquid container 2 is transferred by the pump 83, flows through the supply channel 81, passes through the supply port 42A, and flows into the common liquid chamber RA. Part of the common liquid chamber RA is formed in the communication plate 24, and part of the common liquid chamber RA is formed in the case 28. The ink in the common liquid chamber RA is supplied to the pressure chamber CA through the relay channel 43A. The ink in the pressure chamber CA is discharged from the nozzle N through the communication channels 45A and 45C.

[0026] Ink that is not ejected from nozzle N flows through communication channels 45C and 45B into pressure chamber CB. The ink in pressure chamber CB flows through relay channel 43B and is discharged into common liquid chamber RB. The ink in common liquid chamber RB flows through outlet 42B into recovery channel 82 and is collected in liquid container 2. Ink is circulated in this manner in liquid ejection head 10.

[0027] Next, the structure of the liquid discharge head 10 will be described. The nozzle plate 21 shown in Figures 1 and 2 has a plurality of nozzles N formed on it. The plurality of nozzles N constitute a nozzle row N1. The nozzle row N1 includes a plurality of nozzles N arranged in the Y-axis direction. The nozzles N are through holes that penetrate the nozzle plate 21 in the Z-axis direction.

[0028] The compliance substrate 23 is positioned on both sides of the nozzle plate 21 in the X-axis direction. The compliance substrate 23 includes a flexible film. The compliance substrate 23 forms the bottom surface of the common liquid chambers RA and RB. The compliance substrate 23 is deformable under the pressure of the ink. The compliance substrate 23 deforms under the pressure of the ink and can absorb pressure fluctuations of the ink in the liquid ejection head 10.

[0029] The connecting plate 24 has parts of the common liquid chambers RA and RB, intermediate passages 43A and 43B, and connecting passages 45A to 45C formed in it. The connecting plate 24 has through holes, grooves, or recesses formed in it. These through holes, grooves, or recesses form parts of the common liquid chambers RA and RB, intermediate passage 43, and connecting passage 45.

[0030] The common liquid chambers RA and RB are elongated in the Y-axis direction. The common liquid chambers RA and RB correspond to the arrangement of multiple nozzles N in the Y-axis direction. As shown in Figure 2, the upper portion of the common liquid chambers RA and RB is formed in the case 28, and the lower portion of the common liquid chambers RA and RB is formed in the communication plate 24. The lower portion of the common liquid chambers RA and RB formed in the communication plate 24 penetrates in the Z-axis direction. The portion of the common liquid chamber RA closest to the nozzle N is formed to a position that overlaps with the pressure chamber CA when viewed in the Z-axis direction. Similarly, the portion of the common liquid chamber RB closest to the nozzle N is formed to a position that overlaps with the pressure chamber CB when viewed in the Z-axis direction.

[0031] The relay channel 43A connects the pressure chamber CA and the common liquid chamber RA. Each of the multiple relay channels 43A is provided for a single pressure chamber CA. The multiple relay channels 43A are arranged at predetermined intervals in the Y-axis direction. The relay channel 43B connects the pressure chamber CB and the common liquid chamber RB. Each of the multiple relay channels 43B is provided for a single pressure chamber CB. The multiple relay channels 43B are arranged at predetermined intervals in the Y-axis direction.

[0032] The communication channel 45A communicates with pressure chamber CA and extends in the Z-axis direction. A communication channel 45A is provided for each of the multiple pressure chambers CA. The communication channel 45B communicates with pressure chamber CB and extends in the Z-axis direction. A communication channel 45B is provided for each of the multiple pressure chambers CB.

[0033] The communication channels 45A and 45B penetrate the communication plate 24 in the Z-axis direction. The communication channels 45A and 45B are spaced apart from each other in the X-axis direction. When viewed in the Z-axis direction, communication channel 45A is positioned to overlap with pressure chamber CA. When viewed in the Z-axis direction, communication channel 45B is positioned to overlap with pressure chamber CB. Communication channel 45C extends in the X-axis direction and connects communication channels 45A and 45B. Communication channel 45C is a groove recessed from the bottom surface of the communication plate 24. Communication channel 45C communicates with nozzle N. The multiple communication channels 45A to 45C are arranged at predetermined intervals in the Y-axis direction. The nozzle plate 21 is positioned to cover the communication channels 45A to 45C from below. Pressure chambers CA and CB are connected to each other by the communication channels 45A to 45C.

[0034] Multiple pressure chambers CA and CB are formed in the pressure chamber substrate 25. The pressure chambers CA and CB penetrate the pressure chamber substrate 25 in the Z-axis direction. The pressure chambers CA and CB have a predetermined volume. The pressure chambers CA and CB are spaced apart from each other in the X-axis direction. Multiple pressure chambers CA are provided for each of the multiple nozzles N. Multiple pressure chambers CA are arranged at predetermined intervals in the Y-axis direction. Multiple pressure chambers CB are provided for each of the multiple nozzles N. Multiple pressure chambers CB are arranged at predetermined intervals in the Y-axis direction. As described above, the pressure chamber row CAL includes multiple pressure chambers CA. The pressure chamber substrate 25 can be manufactured from, for example, a silicon single crystal substrate. The pressure chamber substrate 25 may be manufactured from other materials.

[0035] Figure 7 is a cross-sectional view showing a cross-section along the line VII-VII in Figure 6. As shown in Figures 4 and 7, the diaphragm 26 is positioned on the upper surface of the pressure chamber substrate 25. The diaphragm 26 covers the opening of the pressure chamber substrate 25. The portion of the diaphragm 26 that covers the opening of the pressure chamber substrate 25 constitutes the upper wall surface of the pressure chambers CA and CB.

[0036] As shown in Figure 7, the diaphragm 26 includes an elastic layer 26a and an insulating layer 26b. The elastic layer 26a is made of, for example, silicon dioxide (SiO2). The insulating layer 26b is made of, for example, zirconium dioxide (ZrO2). The elastic layer 26a is formed on the pressure chamber substrate 25, and the insulating layer 26b is formed on the elastic layer 26a.

[0037] Multiple piezoelectric elements 50A and 50B are formed on the diaphragm 26. The piezoelectric element 50A shown in Figure 6 is positioned to overlap with the pressure chamber CA when viewed in the Z-axis direction. The piezoelectric element 50B is positioned to overlap with the pressure chamber CB when viewed in the Z-axis direction. Piezoelectric elements 50A are provided for each of the multiple pressure chambers CA. Piezoelectric elements 50B are provided for each of the multiple pressure chambers CB.

[0038] The diaphragm 26 is driven by piezoelectric elements 50A and 50B and vibrates in the Z-axis direction. The diaphragm 26 forming the upper wall surface of pressure chamber CA is driven by piezoelectric element 50A on pressure chamber CA. The diaphragm 26 forming the upper wall surface of pressure chamber CB is driven by piezoelectric element 50B on pressure chamber CB. The total thickness of the diaphragm 26 is, for example, 2 μm or less. The total thickness of the diaphragm 26 may be 15 μm or less, 40 μm or less, or 100 μm or less. For example, if the total thickness of the diaphragm 26 is 15 μm or less, it may include a resin layer. The diaphragm 26 may be made of metal. Examples of metals include stainless steel and nickel. If the diaphragm 26 is made of metal, the plate thickness of the diaphragm 26 may be 15 μm or more and 100 μm or less.

[0039] As shown in Figures 4 and 7, the piezoelectric element 50A has individual electrodes 51A, a common electrode 52A, and a piezoelectric layer 53A. The piezoelectric element 50B has individual electrodes 51B, a common electrode 52B, and a piezoelectric layer 53B. Since the piezoelectric elements 50A and 50B have similar configurations, the description will mainly focus on the piezoelectric element 50A. The description of the piezoelectric element 50B may be omitted.

[0040] The individual electrodes 51A, the piezoelectric layer 53A, and the common electrode 52A are stacked in this order on the diaphragm 26. The piezoelectric layer 53A is sandwiched between the individual electrodes 51A and the common electrode 52A. The individual electrodes 51A are elongated in shape along the X-axis direction. Multiple individual electrodes 51A are arranged with spacing between them in the Y-axis direction. Multiple individual electrodes 51A are arranged for each of the multiple pressure chambers CA. As shown in Figures 5 and 6, multiple individual electrodes 51A are provided for each of the multiple pressure chambers CA. Similarly, multiple individual electrodes 51B are provided for each of the multiple pressure chambers CB. The individual electrodes 51A are positioned to overlap with the multiple pressure chambers CA when viewed in the Z-axis direction. The individual electrodes 51B are positioned to overlap with the multiple pressure chambers CB when viewed in the Z-axis direction.

[0041] The common electrodes 52A and 52B are strip-shaped and extend in the Y-axis direction. The common electrode 52A is continuous so as to cover multiple individual electrodes 51A. The common electrode 52B is continuous so as to cover multiple individual electrodes 51B.

[0042] The individual electrodes 51A and 51B include a base layer and an electrode layer. The base layer includes, for example, titanium (Ti). The electrode layer includes, for example, a low-resistance conductive material such as platinum (Pt) or iridium (Ir). The electrode layer may be formed from oxides such as strontium ruthenate (SrRuO3) and lanthanum nickelate (LaNiO3). The piezoelectric layers 53A and 53B are formed from known piezoelectric materials such as, for example, lead zirconate titanate (Pb(Zr,Ti)O3) or ceramics.

[0043] The common electrodes 52A and 52B include a base layer and an electrode layer. The base layer includes, for example, titanium. The electrode layer includes, for example, a low-resistance conductive material such as platinum or iridium. The electrode layer may be formed of oxides such as strontium ruthenate and lanthanum nickelate. In the piezoelectric layer 53A, the region between the individual electrode 51A and the common electrode 52A becomes the driving region. In the piezoelectric layer 53B, the region between the individual electrode 51B and the common electrode 52B becomes the driving region. Driving regions are formed on each of the multiple pressure chambers CA and CB.

[0044] A predetermined reference voltage is applied to the common electrodes 52A and 52B. The reference voltage is a constant voltage, and is set to a voltage higher than, for example, the ground voltage. A holding signal with a constant voltage is applied to the common electrodes 52A and 52B. A drive signal with a fluctuating voltage is applied to the individual electrodes 51A and 51B. A voltage equivalent to the difference between the reference voltage applied to the common electrode 52A and the drive signal supplied to the individual electrode 51A is applied to the piezoelectric layer 53A. Similarly, a voltage equivalent to the difference between the reference voltage applied to the common electrode 52B and the drive signal supplied to the individual electrode 51B is applied to the piezoelectric layer 53B. The drive signal corresponds to the amount of liquid discharged from the nozzle N.

[0045] When a voltage is applied between the individual electrode 51A and the common electrode 52A, the piezoelectric layer 53A deforms, and the piezoelectric element 50A generates energy to cause the diaphragm 26 to bend and deform. Similarly, when a voltage is applied between the individual electrode 51B and the common electrode 52B, the piezoelectric layer 53B deforms, and the piezoelectric element 50B generates energy to cause the diaphragm 26 to bend and deform.

[0046] The energy generated by the piezoelectric element 50A causes the diaphragm 26 to vibrate, changing the pressure of the liquid in pressure chamber CA, and the liquid in pressure chamber CA is discharged from nozzle N. The energy generated by the piezoelectric element 50B causes the diaphragm 26 to vibrate, changing the pressure of the liquid in pressure chamber CB, and the liquid in pressure chamber CB is discharged from nozzle N.

[0047] The sealing plate 27 has a rectangular shape when viewed in the Z-axis direction. The sealing plate 27 protects the multiple piezoelectric elements 50A and 50B and reinforces the mechanical strength of the pressure chamber substrate 25 and the diaphragm 26. The sealing plate 27 is bonded to the diaphragm 26, for example, by adhesive. The sealing plate 27 is fixed to the pressure chamber substrate 25 via the diaphragm 26.

[0048] As shown in Figures 1 and 2, the COF 60 comprises a flexible printed circuit board 61 and a drive circuit 62. The flexible printed circuit board 61 is a flexible printed circuit board. The flexible printed circuit board 61 is, for example, an FPC. The flexible printed circuit board 61 may also be, for example, an FFC. FPC is an abbreviation for Flexible Printed Circuit. FFC is an abbreviation for Flexible Flat Cable.

[0049] As shown in Figure 2, the flexible wiring board 61 is electrically connected to the individual electrodes 51A and 51B of the piezoelectric elements 50A and 50B via COM wiring 54A and 54B, which will be described later. The flexible wiring board 61 is also electrically connected to the common electrodes 52A and 52B of the piezoelectric elements 50A and 50B via VBS wiring 55A and 55B, which will be described later. The flexible wiring board 61 is electrically connected to a circuit board (not shown). The circuit board includes a drive signal generation circuit 32 as shown in Figure 19.

[0050] The drive circuit 62 is mounted on the flexible wiring board 61. The drive circuit 62 includes a switching element for driving the piezoelectric element 50. The drive circuit 62 is electrically connected to the control unit 30 shown in Figure 19 via the flexible wiring board 61 and the circuit board. The drive circuit 62 receives a drive signal Com output from the drive signal generation circuit 32. The switching element of the drive circuit 62 switches whether or not to supply the drive signal Com generated by the drive signal generation circuit 32 to the piezoelectric elements 50A and 50B. The drive circuit 62 supplies a drive voltage or current to the piezoelectric elements 50A and 50B to vibrate the diaphragm 26.

[0051] As shown in Figures 6 and 7, the liquid discharge head 10 is equipped with COM wiring 54A and 54B. COM wiring 54A is electrically connected to piezoelectric element 50A. COM wiring 54B is electrically connected to piezoelectric element 50B. Multiple COM wirings 54A are connected to multiple individual electrodes 51A. Multiple COM wirings 54B are connected to multiple individual electrodes 51B. Multiple individual electrodes 51A are arranged in the region where the pressure chamber row CAL is formed when viewed in the Z-axis direction. Multiple individual electrodes 51B are arranged in the region where the pressure chamber row CBL is formed when viewed in the Z-axis direction. Since COM wirings 54A and 54B have similar configurations, the explanation will mainly focus on COM wiring 54A, and the explanation of COM wiring 54B may be omitted.

[0052] Multiple COM wirings 54A and 54B extend in the X-axis direction and are drawn into the opening 27a of the sealing plate 27. The opening 27a is shown in Figures 1 and 2. Note that the COM wirings 54A and 54B are not shown in Figure 1. The opening 27a penetrates the sealing plate 27 in the Z-axis direction. When viewed in the Z-axis direction, it is electrically connected to the COF 60 at a position corresponding to the opening 27a. The COM wirings 54A and 54B are formed of a conductive material with lower resistance than the individual electrodes 51A and 51B. For example, the COM wirings 54A and 54B are conductive patterns with a structure in which a gold (Au) conductive film is laminated on the surface of a conductive film formed of nichrome (NiCr).

[0053] COM wiring 54A, 54B has an electrode layer 54a, a first adhesion layer 54b, and a first wiring layer 54c. The electrode layer 54a covers the end face of the piezoelectric layer 53 in the X2 direction. The end face in the X2 direction forms a plane that intersects with the X-axis direction. The first adhesion layer 54b covers the electrode layer 54a and the individual electrodes 51. The first adhesion layer 54b is in close contact with the electrode layer 54a and the individual electrodes 51. The first wiring layer 54c covers the first adhesion layer 54b. The first wiring layer 54c is electrically connected to the individual electrodes 51 via the first adhesion layer 54b.

[0054] Figure 8 is an enlarged plan view showing the main part of the liquid discharge head 10 according to Embodiment 1. COM wiring 54A and 54B are electrically connected to the flexible wiring board 61 via the COF mounting section 64 shown in Figures 3 and 8. The COF mounting section 64 includes a conductive layer that electrically connects the first wiring layer 54c and the wiring section of the flexible wiring board 61. Individual electrode 51A is electrically connected to the drive circuit 62 via COM wiring 54A, the COF mounting section 64, and the flexible wiring board 61. Individual electrode 51B is electrically connected to the drive circuit 62 via COM wiring 54B, the COF mounting section 64, and the flexible wiring board 61.

[0055] The liquid discharge head 10 includes VBS wiring 55A, 55B and VBS wiring mounting sections 56A, 56B, as shown in Figures 3 and 8. VBS wiring 55A is electrically connected to the common electrode 52A. VBS wiring 55B is electrically connected to the common electrode 52B. VBS wiring 55A is electrically connected to the COF 60 via the VBS wiring mounting section 56A. VBS wiring 55B is electrically connected to the COF 60 via the VBS wiring mounting section 56B. VBS wiring 55A is an example of "first common wiring". VBS wiring 55B is an example of "second common wiring".

[0056] As shown in Figure 7, the VBS wiring 55A and the COM wiring 54A are spaced apart in the X-axis direction. An insulating adhesive 59 is provided between the VBS wiring 55A and the COM wiring 54. The sealing plate 27 is bonded to the VBS wiring 55A, 55B, the piezoelectric layers 53A, 53B, and the COM wiring 54, etc., using the adhesive 59.

[0057] As shown in Figure 8, the VBS wiring 55A has a first portion 57A extending in the Y-axis direction and a second portion 58A extending in the X-axis direction from the end 57c of the first portion 57A. The first portion 57A is provided to cover the pressure chamber row CAL when viewed in the Z-axis direction. In the Y-axis direction, the first portion 57A extends to the outside of the pressure chamber row CAL. In the Y-axis direction, the length of the first portion 57A is longer than the length of the pressure chamber row CAL.

[0058] The first portion 57A has a first end 57c and a second end 57d. The first end 57c is the end in the Y1 direction, and the second end 57d is the end in the Y2 direction. The first end 57c is located in the Y1 direction relative to the pressure chamber row CAL. The second end 57b is located in the Y2 direction relative to the pressure chamber row CAL. In the Z-axis direction, a common electrode 52A is formed on the lower side of the first portion 57A. The VBS wiring 55A is arranged to cover the common electrode 52A in the Y-axis direction. The VBS wiring 55A is longer than the common electrode 52A in the Y-axis direction. The VBS wiring 55A may be shorter than the common electrode 52A in the Y-axis direction.

[0059] The second portion 58A extends in the X2 direction from the first end 57a of the first portion 57A. The second portion 58A is located in the Y1 direction of the COF mounting section 64 when viewed in the Z-axis direction. The VBS wiring 55A is not electrically connected to the COF mounting section 64.

[0060] Figure 9 is a cross-sectional view showing a cross-section along the IX-IX line in Figure 8. Figure 9 is a cross-sectional view showing the second portion 58A of the VBS wiring 55A, the VBS wiring mounting portion 56A, and the COF 60. As shown in Figures 8 and 9, the VBS wiring mounting portion 56A is formed on the second portion 58A of the VBS wiring 55A. The VBS wiring mounting portion 56A includes a conductive layer. The flexible wiring board 61 is electrically connected to the VBS wiring mounting portion 56A.

[0061] As shown in Figure 8, the VBS wiring 55B has a first portion 57B extending in the Y-axis direction and a second portion 58B extending in the X-axis direction from the end 57f of the first portion 57B. The first portion 57B is provided to cover the pressure chamber row CBL when viewed in the Z-axis direction. In the Y-axis direction, the first portion 57B extends to the outside of the pressure chamber row CBL. In the Y-axis direction, the length of the first portion 57B is longer than the length of the pressure chamber row CBL.

[0062] The first portion 57B has a first end 57e and a second end 57f. The first end 57e is the end in the Y1 direction, and the second end 57f is the end in the Y2 direction. The first end 57e is located in the Y1 direction relative to the pressure chamber row CBL. The second end 57f is located in the Y2 direction relative to the pressure chamber row CBL. In the Z-axis direction, a common electrode 52B is formed on the underside of the first portion 57B. The VBS wiring 55B is arranged to cover the common electrode 52B in the Y-axis direction. The VBS wiring 55B is longer than the common electrode 52B in the Y-axis direction. The VBS wiring 55B may be shorter than the common electrode 52B in the Y-axis direction.

[0063] The second portion 58A extends in the X2 direction from the first end 57a of the first portion 57A. The second portion 58A is located in the Y1 direction of the COF mounting section 64 when viewed in the Z-axis direction. The VBS wiring 55A is not electrically connected to the COF mounting section 64.

[0064] As shown in Figure 8, the VBS wiring mounting section 56B is formed on the second portion 58B of the VBS wiring 55B. The VBS wiring mounting section 56B includes a conductive layer. The flexible wiring board 61 is electrically connected to the VBS wiring mounting section 56B.

[0065] In this type of liquid discharge head 10, the VBS wiring 55A, which is electrically connected to the common electrode 52A of the pressure chamber row CAL, is electrically connected to the COF 60 via the VBS wiring mounting section 56A. The VBS wiring 55B, which is electrically connected to the common electrode 52B of the pressure chamber row CBL, is electrically connected to the COF 60 via the VBS wiring mounting section 56B. The VBS wiring mounting section 56A is positioned in the Y1 direction relative to the pressure chamber rows CAL and CBL in the Y-axis direction, and the VBS wiring mounting section 56B is positioned in the Y2 direction relative to the pressure chamber rows CAL and CBL in the Y-axis direction.

[0066] In the liquid discharge head 10, the VBS wiring mounting sections 56A and 56B are arranged on opposite sides of each other in the Y-axis direction. Of the multiple piezoelectric elements 50A corresponding to the pressure chamber row CAL, the voltage supplied to the common electrode 52A of piezoelectric element 50A1, which is closest to the VBS wiring mounting section 56A, is the highest, and the voltage supplied to the common electrode 52A of piezoelectric element 50A2, which is furthest from the VBS wiring mounting section 56A, is the lowest. This is due to the voltage drop caused by the electrical resistance of the VBS wiring 55A. Note that piezoelectric elements 50A1 and 50A2 are included in piezoelectric element 50A.

[0067] Of the multiple piezoelectric elements 50B corresponding to the pressure chamber array CBL, the voltage supplied to the common electrode 52A of piezoelectric element 50B2, which is closest to the VBS wiring mounting section 56B, is the highest, while the voltage supplied to the common electrode 52B of piezoelectric element 50B1, which is furthest from the VBS wiring mounting section 56B, is the lowest. This is due to the voltage drop caused by the electrical resistance of the VBS wiring 55B. Note that piezoelectric elements 50B1 and 50B2 are included in piezoelectric element 50B.

[0068] The pressure chamber CA1, located furthest in the Y1 direction among the multiple pressure chamber rows CAL, and the pressure chamber CB1, located furthest in the Y1 direction among the multiple pressure chamber rows CBL, are connected to a common nozzle N. The liquids in pressure chambers CA1 and CB1 are discharged from the same nozzle N.

[0069] The pressure chamber CA2, located furthest in the Y2 direction among the multiple pressure chamber rows CAL, and the pressure chamber CB2, located furthest in the Y2 direction among the multiple pressure chamber rows CBL, communicate with a common nozzle N. The liquid in pressure chambers CA2 and CB2 is discharged from the same nozzle N. The liquid in pressure chambers CA and CB, located at the same position in the Y-axis direction, is discharged from the same nozzle N.

[0070] <Challenges of conventional technology> Next, the problems of the conventional technology will be explained. In the conventional technology, the VBS wiring mounting section was located at both ends in the Y-axis direction. In the conventional technology, voltage was supplied to the VBS wiring connected to the piezoelectric element 50A of pressure chamber row CAL and the VBS wiring connected to the piezoelectric element 50B of pressure chamber row CBL via a common VBS wiring mounting section. As a result, in the Y-axis direction, the voltage supplied to the outer piezoelectric element 50 closer to the VBS wiring mounting section was high, while the voltage supplied to the central piezoelectric element 50 further from the VBS wiring mounting section was low.

[0071] In such conventional technologies, the superimposed effects of voltage drop lead to a problem where there is a large variation in the discharge of liquid from nozzles N that communicate with the outer pressure chambers CA and CB closer to the VBS wiring mounting area, and from nozzles N that communicate with the central pressure chambers CA and CB further away from the VBS wiring mounting area, in the Y-axis direction.

[0072] <Effects of Example 1> As described above, in the liquid discharge head 10 according to Embodiment 1, the VBS wiring mounting section 56A on the A-row side and the VBS wiring mounting section 56B on the B-row side are arranged on opposite sides in the Y-axis direction. Voltage is supplied from opposite directions to the VBS wiring 55A on the A-row side and the VBS wiring 55B on the B-row side. For example, for the pressure chamber CA1 located at the end in the Y1 direction, voltage is supplied from the closer VBS wiring mounting section 56A via the VBS wiring 55A, and for the pressure chamber CB1 located at the end in the Y1 direction, voltage is supplied from the farther VBS wiring mounting section 56B via the VBS wiring 55B. In this case, the voltage drop due to the VBS wiring 55A is smaller than the voltage drop due to the VBS wiring 55B. The effect of voltage drop based on the distance from the VBS wiring mounting sections 56A and 56B is canceled out in the piezoelectric element 50A on the A-row side and the piezoelectric element 50B on the B-row side. Therefore, variations in liquid discharge in multiple nozzles N are suppressed. As a result, the reliability of the liquid dispensing head 10 is improved.

[0073] <Example 2> Next, the liquid discharge head 10B according to Embodiment 2 will be described with reference to Figures 10 and 11. Figure 10 is a cross-sectional view showing a part of the liquid discharge head 10B according to Embodiment 2. Figure 11 is a plan view showing an enlarged view of the main part of the liquid discharge head 10B according to Embodiment 2. The differences between the liquid discharge head 10B according to Embodiment 2 and the liquid discharge head 10 of Embodiment 1 are that the VBS wiring 121A and 122A are provided in place of the VBS wiring 55A on the A column side, the VBS wiring 121B and 122B are provided in place of the VBS wiring 55B on the B column side, the VBS wiring mounting sections 56A and 127A are provided as VBS wiring mounting sections on the A column side, and the VBS wiring mounting sections 56B and 127B are provided as VBS wiring mounting sections on the B column side. In the description of Embodiment 2, explanations similar to those in Embodiment 1 may be omitted. VBS wiring 121A is an example of a "first common wiring". VBS wiring 121B is an example of a "second common wiring". VBS wiring 122A is an example of "third common wiring". VBS wiring 122B is an example of "fourth common wiring".

[0074] As shown in Figure 11, the liquid discharge head 10B has VBS wiring 121A, 122A on the A-row side and VBS wiring 121B, 122B on the B-row side. The VBS wiring 121A, 122A are electrically connected to the common electrode 52A on the A-row side. The VBS wiring 122B, 122B are electrically connected to the common electrode 52B on the B-row side.

[0075] VBS wiring 121A has a first portion 123A extending in the Y-axis direction and a second portion 124A extending in the X-axis direction from the end 123c of the first portion 123A. VBS wiring 122A has a first portion 125A extending in the Y-axis direction and a second portion 126A extending in the X-axis direction from the end 125d of the first portion 125A. The end 123c is the end closer to the pressure chamber CA1 in the Y-axis direction, and the end 125d is the end closer to the pressure chamber CA2 in the Y-axis direction.

[0076] The first portion 123A of VBS wiring 121A and the first portion 125A of VBS wiring 122A are spaced apart in the X-axis direction. The first portion 123A is located further from COF60 than the first portion 125A in the X-axis direction. In other words, the first portion 125A is located closer to the pressure chamber row CBL in the X-axis direction than the first portion 123A. Note that the side closer to COF60 in the X-axis direction may be referred to as the "inside," and the side further from COF60 as the "outside." Also, VBS wiring 121A may be referred to as the "outside VBS wiring 121A," and VBS wiring 122A may be referred to as the "inside VBS wiring 122A."

[0077] As shown in Figure 10, the first portion 125A of the inner VBS wiring 122A is electrically connected to the common electrode 52A in the X-axis direction at a position closer to the COF wiring 60 than the first portion 123A of the outer VBS wiring 121A.

[0078] VBS wiring 121B has a first portion 123B extending in the Y-axis direction and a second portion 124B extending in the X-axis direction from the end 123f of the first portion 123B. VBS wiring 122B has a first portion 125B extending in the Y-axis direction and a second portion 126B extending in the X-axis direction from the end 125e of the first portion 125B. The end 123f is the end closer to the pressure chamber CB2 in the Y-axis direction, and the end 125e is the end closer to the pressure chamber CB1 in the Y-axis direction.

[0079] The first portion 123B of VBS wiring 121B and the first portion 125B of VBS wiring 122B are spaced apart in the X-axis direction. The first portion 123B is located further from COF60 than the first portion 125B in the X-axis direction. In other words, the first portion 125B is located closer to the pressure chamber row CAL in the X-axis direction than the first portion 123B. Note that VBS wiring 121B may be referred to as "outer VBS wiring 121B" and VBS wiring 122B may be referred to as "inner VBS wiring 122B".

[0080] As shown in Figure 10, the first portion 125B of the inner VBS wiring 122B is electrically connected to the common electrode 52B in the X-axis direction at a position closer to the COF wiring 60 than the first portion 123B of the outer VBS wiring 121B.

[0081] As shown in Figure 11, the liquid discharge head 10B includes VBS wiring mounting sections 56A and 127A on the A-row side and VBS wiring mounting sections 56B and 127B on the B-row side. The VBS wiring mounting section 56A is positioned in the Y1 direction relative to the pressure chamber row CAL on the A row side. The VBS wiring mounting section 56A is electrically connected to the outer VBS wiring 121A. The VBS wiring mounting section 56A is provided in the second section 124A. The VBS wiring mounting section 127A is positioned in the Y2 direction relative to the pressure chamber row CAL on the A row side. The VBS wiring mounting section 127A is electrically connected to the inner VBS wiring 122A. The VBS wiring mounting section 127A is provided in the second section 126A.

[0082] The VBS wiring mounting section 56B is positioned in the Y2 direction relative to the pressure chamber row CBL on the B row side. The VBS wiring mounting section 56B is electrically connected to the outer VBS wiring 121B. The VBS wiring mounting section 56B is provided in the second section 124B. The VBS wiring mounting section 127B is positioned in the Y1 direction relative to the pressure chamber row CBL on the B row side. The VBS wiring mounting section 127B is electrically connected to the inner VBS wiring 122B. The VBS wiring mounting section 127B is provided in the second section 126B.

[0083] In the liquid discharge head 10B according to Embodiment 2, VBS wirings 121A and 122A are electrically connected to the common electrode 52A on the A-row side. VBS wiring 121A is electrically connected to COF 60 at one end, and VBS wiring 122A is electrically connected to COF 60 at the other end. Voltage is supplied to the common electrode 52B via VBS wiring mounting sections 56A and 127A located on opposite sides in the Y-axis direction. In the liquid discharge head 10B, VBS wirings 121B and 122B are electrically connected to the common electrode 52B on the B-row side. VBS wiring 121B is electrically connected to COF 60 at the other end, and VBS wiring 122B is electrically connected to COF 60 at the other end. Voltage is supplied to the common electrode 52B via VBS wiring mounting sections 56B and 127B located on opposite sides in the Y-axis direction. This reduces the effect of voltage drop on the common electrodes 52A and 52B, thereby suppressing variations in liquid discharge from multiple nozzles N aligned in the Y-axis direction.

[0084] <Example 3> Next, with reference to Figure 12, the liquid discharge head 10C according to Embodiment 3 will be described. Figure 12 is a plan view showing an enlarged view of the main part of the liquid discharge head according to Embodiment 3. The differences between the liquid discharge head 10C according to Embodiment 3 and the liquid discharge head 10B according to Embodiment 1 are that the VBS wiring 131A and 132A are provided in place of the VBS wiring 55A on the A column side, the VBS wiring 131B and 132B are provided in place of the VBS wiring 55B on the B column side, a connecting part 133 is provided to connect the VBS wiring 131A and the VBS wiring 131B, a connecting part 134 is provided to connect the VBS wiring 132A and the VBS wiring 132B, a VBS wiring mounting part 136 is provided on the connecting part 133, and a VBS wiring mounting part 137 is provided on the connecting part 134. In the description of Embodiment 3, explanations similar to those for Embodiments 1 and 2 may be omitted. The VBS wiring 131A is an example of a "first common wiring". VBS wiring 132B is an example of "second common wiring". VBS wiring 132A is an example of "third common wiring". VBS wiring 131B is an example of "fourth common wiring".

[0085] The liquid dispensing head 10C has VBS wiring 131A, 132A on the A-row side and VBS wiring 131B, 132B on the B-row side. VBS wiring 131A, 132A are electrically connected to the common electrode 52A on the A-row side. VBS wiring 132B, 132B are electrically connected to the common electrode 52B on the B-row side.

[0086] VBS wiring 131A and 132A extend in the Y-axis direction and are spaced apart from each other in the X-axis direction. VBS wiring 132A is positioned closer to COF60 than VBS wiring 131A in the X-axis direction. VBS wiring 131A extends beyond the pressure chamber row CAL in the Y1 direction. End 131c of VBS wiring 131A is located beyond the pressure chamber row CAL in the Y1 direction. VBS wiring 132A extends beyond the pressure chamber row CAL in the Y2 direction. End 132d of VBS wiring 132A is located beyond the pressure chamber row CAL in the Y2 direction.

[0087] VBS wiring 131B and 132B extend in the Y-axis direction and are spaced apart from each other in the X-axis direction. VBS wiring 132B is located closer to COF60 than VBS wiring 131B in the X-axis direction. VBS wiring 131B extends beyond pressure chamber row CBL in the Y1 direction. End 131e of VBS wiring 131B is located beyond pressure chamber row CAL in the Y1 direction. VBS wiring 132B extends beyond pressure chamber row CBL in the Y2 direction. End 132f of VBS wiring 132B is located beyond pressure chamber row CBL in the Y2 direction.

[0088] As described above, the liquid discharge head 10C comprises connecting parts 133, 134 and VBS wiring mounting parts 136, 137. Connecting part 133 extends in the X-axis direction and connects the ends 131c, 131e of the VBS wiring 131A, 131B. Connecting part 133 connects the outer VBS wiring 131A, 131B in the X-axis direction. Connecting part 133 is located in the Y1 direction relative to the pressure chamber rows CAL, CBL. The connecting part 133 is provided with a VBS wiring mounting part 136. The VBS wiring 131A, 131B are electrically connected to the COF 60 via the VBS wiring mounting part 136 and the connecting part 133. The VBS wiring 131A, 131B are electrically connected to the COF 60 at a position on one side of the pressure chamber rows CAL, CBL. "Position on one side" includes a position shifted in the Y1 direction relative to the center line OX in the Y-axis direction. Furthermore, the "position on the other side" described later includes positions that are shifted in the Y2 direction from the center line OX in the Y-axis direction.

[0089] The connecting portion 134 extends in the X-axis direction and connects the ends 132d and 131f of the VBS wiring 132A and 132B. The connecting portion 134 is located in the Y2 direction relative to the pressure chamber rows CAL and CBL. The connecting portion 134 is provided with a VBS wiring mounting portion 137. The VBS wiring 132A and 132B are electrically connected to the COF 60 via the VBS wiring mounting portion 137 and the connecting portion 134. The VBS wiring 132A and 132B are also electrically connected to the COF 60 at a location on the other side of the pressure chamber rows CAL and CBL.

[0090] In the liquid discharge head 10C according to this embodiment 3, the effect of voltage drop due to the VBS wiring 131A, 131B, 132A, and 132B in the Y-axis direction is also taken into consideration. With this liquid discharge head 10C, variations in liquid discharge from multiple nozzles N arranged in the Y-axis direction are suppressed.

[0091] <Example 4> Next, with reference to Figure 13, the liquid discharge head 10D according to Embodiment 4 will be described. Figure 13 is a plan view showing an enlarged view of the main part of the liquid discharge head according to Embodiment 4. The differences between the liquid discharge head 10D according to Embodiment 4 and the liquid discharge head 10B according to Embodiment 2 are that it is equipped with a connecting part 141 that connects the VBS wiring 121A and the VBS wiring 122B, and a VBS wiring mounting part 146 provided on the connecting part 141. In the description of Embodiment 4, explanations similar to those for Embodiments 1 to 3 may be omitted.

[0092] The liquid discharge head 10D has VBS wiring 121A, 122A on the A-row side and VBS wiring 121B, 122B on the B-row side. VBS wiring 121A, 122A are electrically connected to the common electrode 52A on the A-row side. VBS wiring 121B, 122B are electrically connected to the common electrode 52B on the B-row side.

[0093] The liquid discharge head 10D includes connecting sections 141 and 142 and VBS wiring mounting sections 146 and 147. The connecting section 141 extends in the X-axis direction and connects the ends 121c and 122e of the VBS wirings 121A and 122B. The end 121c of the VBS wiring 121A is located in the Y1 direction relative to the pressure chamber row CAL. The end 122e of the VBS wiring 122B is located in the Y1 direction relative to the pressure chamber row CBL. The connecting section 141 connects the outer VBS wiring 121A on the A row side and the inner VBS wiring 122B on the B row side. The connecting section 141 is located in the Y1 direction relative to the pressure chamber rows CAL and CBL. The connecting section 141 is provided with a VBS wiring mounting section 146. The VBS wirings 121A and 122B are electrically connected to the COF 60 via the VBS wiring mounting section 146 and the connecting section 141. VBS wiring 121A and 122B are electrically connected to COF60 at a location on one side of pressure chamber rows CAL and CBL.

[0094] The connecting section 142 extends in the X-axis direction and connects the ends 122d and 121f of the VBS wirings 122A and 121B. The end 122d of VBS wiring 122A is located in the Y2 direction relative to the pressure chamber row CAL. The end 121f of VBS wiring 121B is located in the Y2 direction relative to the pressure chamber row CBL. The connecting section 142 connects the inner VBS wiring 122A on the A row side and the outer VBS wiring 121B on the B row side. The connecting section 142 is located in the Y2 direction relative to the pressure chamber rows CAL and CBL. The connecting section 142 is provided with a VBS wiring mounting section 147. The VBS wirings 122A and 121B are electrically connected to the COF 60 via the VBS wiring mounting section 147 and the connecting section 142. The VBS wirings 122A and 121B are electrically connected to the COF 60 at a position on the other side of the pressure chamber rows CAL and CBL.

[0095] In the liquid discharge head 10D according to this embodiment 4, the effect of voltage drop due to the VBS wiring 121A, 121B, 122A, and 122B in the Y-axis direction is also taken into consideration. With this liquid discharge head 10D, variations in liquid discharge from multiple nozzles N arranged in the Y-axis direction are suppressed.

[0096] <Example 5> Next, with reference to Figure 14, the liquid discharge head 10E according to Example 5 will be described. Figure 14 is a plan view showing an enlarged view of the main part of the liquid discharge head according to Example 5. The difference between the liquid discharge head 10E according to Example 5 and the liquid discharge head 10 according to Example 1 is that it is equipped with VBS wiring 151A instead of VBS wiring 55A, and VBS wiring 151B instead of VBS wiring 55B and VBS wiring 55B. In the description of Example 5, explanations similar to those for Examples 1 to 4 may be omitted. VBS wiring 151A is an example of "first common wiring". VBS wiring 151B is an example of "second common wiring".

[0097] The liquid dispensing head 10E has a VBS wiring 151A on the A-row side and a VBS wiring 151B on the B-row side. The VBS wiring 151A is electrically connected to the common electrode 52A on the A-row side. The VBS wiring 151B is electrically connected to the common electrode 52B on the B-row side.

[0098] The VBS wiring 151A has a first portion 157A extending in the Y-axis direction, a second portion 158A extending from the first portion 157A in the Y1 direction, and a third portion 159A extending from the second portion 158A in the X2 direction. The first portion 157A is provided so as to cover the pressure chamber row CAL when viewed in the Z-axis direction. The first portion 157A has a length in the Y-axis direction that is opposite to the pressure chamber row CAL. In the Y-axis direction, the length of the first portion 157A is approximately the same as the length of the pressure chamber row CAL.

[0099] The third section 159A is provided with a VBS wiring implementation section 56A. The VBS wiring 151A is electrically connected to the COF 60 via the VBS wiring implementation section 56A.

[0100] The first portion 157A has a first end 157c and a second end 157d. The first end 157c is the end in the Y1 direction, and the second end 157d is the end in the Y2 direction. The first end 157c is located in the Y1 direction relative to the pressure chamber row CAL. The second end 157d is located in the Y2 direction relative to the pressure chamber row CAL. The width W1 of the first end 157c along the X-axis direction is wider than the width W2 of the second end 157d along the X-axis direction. In the Y-axis direction, the width W1 of the first end 157c closer to the VBS wiring mounting section 56A is wider than the width W2 of the second end 157d further from the VBS wiring mounting section 56A. The width of the first portion 157A is wider closer to the VBS wiring mounting section 56A and narrower further away from the VBS wiring mounting section 56A.

[0101] The VBS wiring 151B has a first portion 157B extending in the Y-axis direction, a second portion 158B extending from the first portion 157B in the Y2 direction, and a third portion 159B extending from the second portion 158B in the X1 direction. The first portion 157B is provided so as to cover the pressure chamber row CBL when viewed in the Z-axis direction. In the Y-axis direction, the first portion 157B has a length opposite to the pressure chamber row CBL. In the Y-axis direction, the length of the first portion 157B is approximately the same as the length of the pressure chamber row CBL.

[0102] The third section 159B is provided with a VBS wiring implementation section 56B. The VBS wiring 151B is electrically connected to the COF 60 via the VBS wiring implementation section 56B.

[0103] The first part 157B has a first end 157e and a second end 157f. The first end 157e is the end in the Y2 direction, and the second end 157f is the end in the Y2 direction. The first end 157e is located in the Y2 direction relative to the pressure chamber row CBL. The second end 157f is located in the Y2 direction relative to the pressure chamber row CBL. The width W3 of the first end 157e along the X-axis direction is narrower than the width W4 of the second end 157f along the X-axis direction. In the Y-axis direction, the width W4 of the second end 157d closer to the VBS wiring mounting section 56B is wider than the width W3 of the first end 157e further from the VBS wiring mounting section 56B. The width of the first part 157B is wider closer to the VBS wiring mounting section 56B and narrower further away from the VBS wiring mounting section 56B. The widths W1 and W4 are approximately the same length. Widths W2 and W3 are approximately the same length.

[0104] In the liquid discharge head 10E according to this embodiment 5, the width of the first portion 157A of the VBS wiring 151A on the A column side widens as it moves away from the center line OX in the Y1 direction and narrows as it moves away from the center line OX in the Y2 direction. On the other hand, the width of the first portion 157B of the VBS wiring 151B on the B column side narrows as it moves away from the center line OX in the Y1 direction and widens as it moves away from the center line OX in the Y2 direction.

[0105] In the liquid discharge head 10E according to this embodiment 5, the effect of voltage drop due to VBS wiring 151A and 151B in the Y-axis direction is also taken into consideration. With this liquid discharge head 10E, variations in liquid discharge from multiple nozzles N arranged in the Y-axis direction are suppressed.

[0106] <Example 6> Next, the liquid discharge head 10F according to Example 6 will be described with reference to Figures 15 and 16. Figure 15 is a cross-sectional view showing the pressure chambers CA1 and CA2 on the A-row side of the liquid discharge head 10F according to Example 6. The difference between the liquid discharge head 10F according to Example 6 and the liquid discharge head 10 according to Example 1 is that the thicknesses T1 to T4 of the VBS wiring 55A and 55B differ depending on their position in the Y-axis direction. In the description of Example 6, explanations similar to those for Examples 1 to 5 may be omitted. Thicknesses T1 to T4 are thicknesses along the Z-axis direction.

[0107] Pressure chamber CA1, shown in Figure 15, is one of several pressure chambers CA located at one end in the Y-axis direction. Pressure chamber CA2 is one of several pressure chambers CA located at the other end in the Y-axis direction. Pressure chamber CA1 is closest to the VBS wiring mounting section 56A in the Y-axis direction. Pressure chamber CA2 is furthest from the VBS wiring mounting section 56A in the Y-axis direction.

[0108] The thickness T1 of the VBS wiring 55A closer to pressure chamber CA1 is greater than the thickness T2 of the VBS wiring 55A closer to pressure chamber CA2. The thickness of the VBS wiring 55A increases as you move away from the center line OX in the Y1 direction, as shown in Figure 8, and decreases as you move away from the center line OX in the Y2 direction.

[0109] Pressure chamber CB1, shown in Figure 16, is one of several pressure chambers CB located at one end in the Y-axis direction. Pressure chamber CB2 is one of several pressure chambers CB located at the other end in the Y-axis direction. Pressure chamber CB1 is the furthest from the VBS wiring mounting section 56B in the Y-axis direction. Pressure chamber CB2 is the closest to the VBS wiring mounting section 56B in the Y-axis direction.

[0110] The thickness T3 of the VBS wiring 55B closer to pressure chamber CB1 is greater than the thickness T2 of the VBS wiring 55B closer to pressure chamber CB2. The thickness of the VBS wiring 55B decreases as you move away from the center line OX in the Y1 direction, as shown in Figure 8, and increases as you move away from the center line OX in the Y2 direction.

[0111] In the liquid discharge head 10F according to this embodiment 6, the width of the first portion 157A of the VBS wiring 151A on the A column side widens as it moves away from the center line OX in the Y1 direction and narrows as it moves away from the center line OX in the Y2 direction. On the other hand, the width of the first portion 157B of the VBS wiring 151B on the B column side narrows as it moves away from the center line OX in the Y1 direction and widens as it moves away from the center line OX in the Y2 direction.

[0112] In the liquid discharge head 10F according to this embodiment 6, the effect of voltage drop due to VBS wiring 151A and 151B in the Y-axis direction is also taken into consideration. With this liquid discharge head 10E, variations in liquid discharge from multiple nozzles N arranged in the Y-axis direction are suppressed.

[0113] <Example 7> Next, the liquid discharge head 10G according to Example 7 will be described with reference to Figures 11 and 17. Figure 17 is a cross-sectional view showing the liquid discharge head 10G according to Example 7. The differences between the liquid discharge head 10G according to Example 7 and the liquid discharge head 10B according to Example 1 shown in Figure 2 are that, instead of having a nozzle N that commonly communicates with the pressure chamber CA on the A-row side and the pressure chamber CB on the B-row side, it is equipped with a nozzle NA that communicates with the pressure chamber CA on the A-row side and a nozzle NB that communicates with the pressure chamber CB on the B-row side separately, and that the VBS wiring 55A, 55B is replaced with VBS wiring 121A, 121B, 122A, 122B. The VBS wiring 121A, 121B, 122A, 122B of the liquid discharge head 10G according to Example 7 are the same as the VBS wiring 121A, 121B, 122A, 122B of the liquid discharge head 10B according to Example 2 shown in Figure 11. In the description of Example 7, explanations similar to those for Examples 1 to 6 may be omitted.

[0114] The liquid discharge head 10G shown in Figure 17 is equipped with multiple pressure chambers CA and CB. Pressure chamber CA is connected to a common liquid chamber RA, an intermediate passage 43A, a connecting passage 45A, and a nozzle NA. Pressure chamber CB is connected to a common liquid chamber RB, an intermediate passage 43B, a connecting passage 45B, and a nozzle NB.

[0115] In the liquid discharge head 10G according to this embodiment 7, the effect of voltage drop due to VBS wiring 121A, 121B, 122A, and 122B in the Y-axis direction is also taken into consideration. As shown in Figure 11, the pressure chamber CA located at one end in the Y-axis direction is close to the VBS wiring mounting section 56A and far from the VBS wiring mounting section 127A. The common electrode 52A on the pressure chamber CA1 is electrically connected to the closer VBS wiring mounting section 56A via VBS wiring 121A, and is electrically connected to the farther VBS wiring mounting section 127A via VBS wiring 122A.

[0116] Pressure chamber CA2, located at the other end in the Y-axis direction, is far from VBS wiring mounting section 56A and close to VBS wiring mounting section 127A. The common electrode 52A on pressure chamber CA2 is electrically connected to the farther VBS wiring mounting section 56A via VBS wiring 121A, and is also electrically connected to the closer VBS wiring mounting section 127A via VBS wiring 122A. The common electrodes 52B of pressure chambers CB, CB1, and CB2 on the B-row side are also electrically connected to the opposite VBS wiring mounting sections 56B and 176B, respectively.

[0117] In the liquid discharge head 10G according to this embodiment 7, the effect of voltage drop due to VBS wiring 121A, 121B, 122A, 122B in the Y-axis direction is taken into consideration, so variations in liquid discharge in multiple nozzles NA, NB arranged in the Y-axis direction are suppressed.

[0118] The liquid discharge head 10G according to Example 7 is equipped with VBS wiring 121A, 121B, 122A, 122B and VBS wiring mounting sections 56A, 56B, 127A, 127B similar to those in Example 2 shown in Figure 11, but the arrangement of the VBS wiring 121A, 121B, 122A, 122B and VBS wiring mounting sections 56A, 56B, 127A, 127B is not limited thereto. The liquid discharge head 10G may also be configured to include VBS wiring 121A, 121B, 122A, 122B, 131A, 131B, 132A, 132B, for example, as shown in Figure 12 or Figure 13. Furthermore, the VBS wiring 121A, 121B, 122A, 122B of the liquid discharge head 10G may have different thicknesses T1 to T4 depending on their position in the Y-axis direction, similar to Example 6.

[0119] <Liquid discharge device> Next, a liquid dispensing device 1 equipped with a liquid dispensing head 10 will be described with reference to Figures 18 and 19. Figure 18 is a schematic diagram showing a liquid dispensing device 1 equipped with a liquid dispensing head 10. The liquid dispensing device 1 is equipped with the liquid dispensing head 10 according to the above-described embodiment 1. Figure 18 is a block diagram of the liquid dispensing device 1. Note that the liquid dispensing device 1 is not limited to a configuration equipped with the liquid dispensing head 10 according to embodiment 1. The liquid dispensing device 1 may be equipped with liquid dispensing heads 10B to 10G according to embodiments 2 to 7 instead of the liquid dispensing head 10 according to embodiment 1.

[0120] Liquid ejection device 1 is an inkjet printing device that ejects ink, an example of a "liquid," as droplets onto a medium PA. Liquid ejection device 1 is a serial-type printing device. Medium PA is typically printing paper. However, medium PA is not limited to printing paper and may be any material to be printed on, such as resin film or fabric.

[0121] The liquid dispensing device 1 comprises a liquid dispensing head 10 for dispensing ink, a liquid container 2 for storing ink, a carriage 3 on which the liquid dispensing head 10 is mounted, a carriage transport mechanism 4 for transporting the carriage 3, a medium transport mechanism 5 for transporting the medium PA, and a control unit 30. The control unit 30 is a control unit that controls the dispensing of the liquid.

[0122] Specific embodiments of the liquid container 2 include, for example, a cartridge detachable from the liquid dispensing device 1, a bag-shaped ink pack made of a flexible film, and an ink tank that can be refilled with ink. The type of ink stored in the liquid container 2 is arbitrary. The liquid dispensing device 1 may be equipped with multiple liquid containers 2 corresponding to, for example, four colors of ink. The four colors of ink may be, for example, cyan, magenta, yellow, and black. The liquid containers 2 may also be mounted on the carriage 3.

[0123] The liquid ejection device 1 includes a circulation mechanism 8 for circulating ink. The circulation mechanism 8 includes a supply channel 81 for supplying ink to the liquid ejection head 10, a recovery channel 82 for recovering the ink discharged from the liquid ejection head 10, and a pump 83 for transferring the ink.

[0124] The carriage transport mechanism 4 has a transport belt 4a and a motor for transporting the carriage 3. The medium transport mechanism 5 has transport rollers 5a and a motor for transporting the medium PA. The carriage transport mechanism 4 and the medium transport mechanism 5 are controlled by the control unit 30. The liquid dispensing device 1 transports the carriage 3 by the carriage transport mechanism 4 while the medium PA is transported by the medium transport mechanism 5, and prints by dispensing ink droplets onto the medium PA.

[0125] The liquid dispensing device 1 includes a linear encoder 6, as shown in Figure 19. It is positioned to detect the position of the carriage 3. The linear encoder 6 acquires information regarding the position of the carriage 3. As the carriage 3 moves, the linear encoder 6 outputs an encoder signal to the control unit 30.

[0126] The control unit 30 includes one or more CPUs 31. The control unit 30 may also include an FPGA instead of, or in addition to, the CPUs 31. The control unit 30 includes a storage unit 35. The storage unit 35 includes, for example, a ROM 36 and a RAM 37. The storage unit 35 may also include an EEPROM or a PROM. The storage unit 35 can store print data Img supplied from the host computer. The storage unit 35 stores the control program for the liquid dispensing device 1.

[0127] CPU is an abbreviation for Central Processing Unit. FPGA is an abbreviation for field-programmable gate array. RAM is an abbreviation for Random Access Memory. ROM is an abbreviation for Read Only Memory. EEPROME is an abbreviation for Electrically Erasable Programmable Read-Only Memory. PROM is an abbreviation for Programmable ROM.

[0128] The control unit 30 generates signals to control the operation of each part of the liquid dispensing device 1. The control unit 30 can generate a print signal SI and a waveform specification signal dCom. The print signal SI is a digital signal that specifies the type of operation of the liquid dispensing head 20. The print signal SI can specify whether or not to supply a drive signal Com to the piezoelectric element 50. The waveform specification signal dCom is a digital signal that defines the waveform of the drive signal Com. The drive signal Com is an analog signal for driving the piezoelectric element 50.

[0129] The liquid dispensing device 1 includes a drive signal generation circuit 32. The drive signal generation circuit 32 is electrically connected to the control unit 30. The drive signal generation circuit 32 includes a DA conversion circuit. The drive signal generation circuit 32 generates a drive signal Com having a waveform defined by a waveform specification signal dCom. When the control unit 30 receives an encoder signal from the linear encoder 6, it outputs a timing signal PTS to the drive signal generation circuit 32. The timing signal PTS defines the generation timing of the drive signal Com. The drive signal generation circuit 32 outputs the drive signal Com each time it receives the timing signal PTS.

[0130] The drive circuit 62 is electrically connected to the control unit 30 and the drive signal generation circuit 32. Based on the print signal SI, the drive circuit 62 switches whether or not to supply the drive signal Com to the piezoelectric element 50. Based on the print signal SI, latch signal LAT, and change signal CH supplied from the control unit 30, the drive circuit 62 can select the piezoelectric element 50 to which the drive signal Com is supplied. The latch signal LAT defines the latch timing of the print data Img. The change signal CH defines the selection timing of the drive pulse included in the drive signal Com.

[0131] The control unit 30 controls the ink ejection operation by the liquid ejection head 20. As described above, the control unit 30 drives the piezoelectric element 50 to fluctuate the ink pressure in the pressure chamber C and eject ink from the nozzle N. The control unit 30 controls the ejection operation when performing a printing operation.

[0132] The above-described liquid dispensing head 10 can be applied to such a liquid dispensing device 1. In the liquid dispensing device 1 equipped with the liquid dispensing head 10, the VBS wiring mounting section 56A on the A-row side and the VBS wiring mounting section 56B on the B-row side are arranged on opposite sides in the Y-axis direction. Voltage is supplied from opposite directions to the VBS wiring 55A on the A-row side and the VBS wiring 55B on the B-row side. As a result, the effect of voltage drop based on the distance from the VBS wiring mounting sections 56A and 56B is canceled out in the piezoelectric element 50A on the A-row side and the piezoelectric element 50B on the B-row side. Therefore, variations in liquid dispensing in multiple nozzles N are suppressed. As a result, the reliability of the liquid dispensing device 1 equipped with the liquid dispensing head 10 is improved.

[0133] <Example 1> Next, the liquid discharge head 10 according to Modification 1 will be described. The difference between the liquid discharge head 10 according to Modification 1 and the liquid discharge head 10 according to the embodiment is that the width of the VBS wiring 55A and 55B along the X-axis direction differs depending on the position in the Y-axis direction. Note that explanations similar to those given in Embodiments 1 to 7 above may be omitted.

[0134] In the liquid discharge head 10 according to Modification 1, a VBS wiring mounting section 56A is located at one end, and a VBS wiring mounting section 56B is located at the other end. VBS wiring 55A is electrically connected to the VBS wiring mounting section 56A, and VBS wiring 55B is electrically connected to the VBS wiring mounting section 56B.

[0135] In the liquid discharge head 10 according to Modification 1, the VBS wiring 55A is formed such that the electrical resistance of the VBS wiring 55A on the A column side decreases as you move along the Y-axis from one side to the other. Specifically, the width W11 at one end of the VBS wiring 55A is narrower than the width W12 at the other end of the VBS wiring 55A. Note that width W11 is in the same position in the Y-axis direction as width W1 shown in Figure 14, and width W12 is in the same position in the Y-axis direction as width W2.

[0136] In the liquid discharge head 10 according to Modification 1, the VBS wiring 55B is formed such that the electrical resistance of the VBS wiring 55B on the B column side decreases as you move along the Y axis from one side to the other. Specifically, the width W13 at one end of the VBS wiring 55B is wider than the width W14 at the other end of the VBS wiring 55B. Note that width W13 is at the same position in the Y axis direction as width W3 shown in Figure 14, and width W14 is at the same position in the Y axis direction as width W4.

[0137] In the liquid discharge head 10 according to this modified example 1, the effect of voltage drop due to VBS wiring 55A and 55B in the Y-axis direction is taken into consideration, so variations in liquid discharge in multiple nozzles NA and NB aligned in the Y-axis direction are suppressed.

[0138] <Modification 2> Next, the liquid discharge head 10 according to Modification 2 will be described. The difference between the liquid discharge head 10 according to Modification 2 and the liquid discharge head 10 according to the embodiment is that the thickness of the VBS wiring 55A and 55B along the Z-axis direction differs depending on the position in the Y-axis direction. Note that explanations similar to those given in the descriptions of Embodiments 1 to 7 and Modification 1 above may be omitted.

[0139] In the liquid discharge head 10 according to Modification 2, the VBS wiring 55A is formed such that the electrical resistance of the VBS wiring 55A on the A column side decreases as you move along the Y axis from one side to the other. Specifically, the thickness T11 at one end of the VBS wiring 55A is thinner than the thickness T12 at the other end of the VBS wiring 55A (T11 <T12)。

[0140] In the liquid discharge head 10 according to Modification 2, the VBS wiring 55B is formed such that the electrical resistance of the VBS wiring 55B on the B column side decreases as you move along the Y axis from one side to the other. Specifically, the thickness T13 at one end of the VBS wiring 55B is thicker than the thickness T14 at the other end of the VBS wiring 55B (T13 <T14)。

[0141] In the liquid discharge head 10 according to this modified example 2, the effect of voltage drop due to the VBS wiring 55A and 55B in the Y-axis direction is taken into consideration, so variations in liquid discharge in the multiple nozzles NA and NB aligned in the Y-axis direction are suppressed.

[0142] The embodiments described above merely represent typical forms of the present invention, and the present invention is not limited to the embodiments described above. Various modifications and additions are possible without departing from the spirit of the present invention.

[0143] In the above embodiment, the example is given where the VBS wirings 55A and 55B and COF 60 are electrically connected outside the pressure chamber rows CAL and CBL in the Y-axis direction. However, the position where the VBS wirings 55A and 55B and COF 60 are electrically connected is not limited to this. For example, the position where the VBS wiring 55A and COF 60 are electrically connected may be a position shifted in the Y1 direction from the center line OX. The position where the VBS wiring 55B and COF 60 are electrically connected may be a position shifted in the Y2 direction from the center line OX. For example, the position where the VBS wiring 55A and COF 60 are electrically connected may be a position that overlaps with the pressure chamber row CAL when viewed in the Z-axis direction, and may also be a position shifted in the Y1 direction from the center line OX. The position where the VBS wiring 55B and COF 60 are electrically connected may be a position that overlaps with the pressure chamber row CBL when viewed in the Z-axis direction, and may also be a position shifted in the Y2 direction from the center line OX. Note that "one side" is not limited to a position shifted in the Y1 direction from the center line OX, but may also be a position shifted in the Y2 direction. Similarly, "the other side" is not limited to a position shifted in the Y2 direction from the center line OX, but may also be a position shifted in the Y1 direction. "One side" and "the other side" are opposite each other when the center line OX is used as the reference point.

[0144] In the above-described embodiment 1, the VBS wiring 55A is electrically connected to COF60 at one end, but not at the other end. Similarly, in embodiment 1, the VBS wiring 55B is electrically connected to COF60 at the other end, but not at the one end.

[0145] Furthermore, while COM wiring 54A, COM54B, VBS wiring 55A, and VBS wiring 55B are each electrically connected to COF60, these COM wiring 54A, COM54B, VBS wiring 55A, and VBS wiring 55B are connected to different wiring sections of COF60, and not to a common wiring section.

[0146] VBS wiring 55A is arranged such that the wiring resistance differs from one side to the other in the Y-axis direction, and VBS wiring 55B is also arranged such that the wiring resistance differs from one side to the other in the Y-axis direction. As described above, the wiring resistance can be made different by changing the width or thickness of the VBS wiring.

[0147] For example, the VBS wiring on column A may be arranged such that the wiring resistance increases as you move from one side to the other in the Y-axis direction, and the VBS wiring on column B may be arranged such that the wiring resistance increases as you move from the other side to the one side in the Y-axis direction.

[0148] For example, the VBS wiring on column A may be arranged such that the wiring resistance decreases as you move from one side to the other in the Y-axis direction, and the VBS wiring on column B may be arranged such that the wiring resistance decreases as you move from the other side to the one side in the Y-axis direction.

[0149] In the above Example 1, a liquid discharge head 10 in which the liquid circulates is illustrated as an example, but the present invention may also be applied to a liquid discharge head 10 in which the liquid does not circulate.

[0150] In the above-described embodiment 1, we illustrated the case where a total of two pressure chambers, one first pressure chamber CA and one second pressure chamber CB, are connected to one nozzle N. However, a total of four pressure chambers may be connected to one nozzle N: two first pressure chambers CA adjacent to each other in the Y-axis direction and two second pressure chambers CB adjacent to each other in the Y-axis direction.

[0151] In the embodiments described above, a serial-type liquid dispensing device is illustrated in which a carriage equipped with a liquid dispensing head 10 is reciprocated in the width direction of the medium PA. However, the present invention may also be applied to a line-type liquid dispensing device 1 equipped with a line head that has multiple liquid dispensing heads 10.

[0152] The liquid ejection device 1 illustrated in the above-described embodiment can be used in various devices such as facsimile machines and photocopiers, in addition to equipment dedicated to printing. However, the applications of the liquid ejection device of the present invention are not limited to printing. For example, a liquid ejection device that ejects a colorant solution can be used as a manufacturing device for forming color filters for display devices such as liquid crystal display panels. A liquid ejection device that ejects a conductive material solution can be used as a manufacturing device for forming wiring and electrodes on a wiring board. A liquid ejection device that ejects a solution of organic matter related to living organisms can be used, for example, as a manufacturing device for producing biochips. [Explanation of symbols]

[0153] 1…Liquid dispensing device, 10, 10B, 10C, 10D, 10E, 10F, 10G…Liquid dispensing head, 30…Control unit, 51A…Individual electrode (1st individual electrode), 51B…Individual electrode (2nd individual electrode), 52A…Common electrode (1st common electrode), 52B…Common electrode (2nd common electrode), 53A…Piezoelectric layer (1st piezoelectric), 53B…Piezoelectric layer (2nd piezoelectric), 54A…COM wiring (1st individual wiring), 54B…COM wiring (2nd individual wiring), 55A…VBS wiring (1st common wiring), 55B…VBS wiring (2nd common wiring), 60…COF, 61…Flexible wiring board (wiring material), 121A…VBS wiring (1st common wiring), 121B…VBS wiring (2nd common wiring), 122A …VBS wiring (3rd common wiring), 122B…VBS wiring (4th common wiring), 131A…VBS wiring (1st common wiring), 131B…VBS wiring (4th common wiring), 132A…VBS wiring (3rd common wiring), 132B…VBS wiring (2nd common wiring), CA…Pressure chamber (1st pressure chamber), CB…Pressure chamber (2nd pressure chamber), CAL…Pressure chamber row (1st pressure chamber row), CBL…Pressure chamber row (2nd pressure chamber row), RA…Common liquid chamber (common supply channel), RB…Common liquid chamber (common discharge channel), OX…Centerline, N…Nozzle, N1…Nozzle row, NA…Nozzle (1st nozzle), NB…Nozzle (2nd nozzle), X…X-axis direction (2nd direction), Y…Y-axis direction (1st direction), Z…Z-axis direction (3rd direction).

Claims

1. A liquid dispensing head, A first pressure chamber row in which multiple first pressure chambers are arranged in a first direction, Multiple second pressure chambers are arranged in the first direction, and a row of second pressure chambers is provided at different positions in a second direction intersecting the first direction and the first pressure chambers. A plurality of nozzles, each in common with the first pressure chamber and the second pressure chamber, are arranged in a nozzle row in the first direction, A first piezoelectric element provided corresponding to the plurality of first pressure chambers, A first individual electrode is electrically connected to the first piezoelectric element and is provided individually for each of the plurality of first pressure chambers, A first common electrode is electrically connected to the first piezoelectric element and is provided in common to the plurality of first pressure chambers, A second piezoelectric element provided corresponding to the plurality of second pressure chambers, A second individual electrode is electrically connected to the second piezoelectric element and is provided individually for each of the plurality of second pressure chambers, A second common electrode is electrically connected to the second piezoelectric element and is provided in common to the plurality of second pressure chambers, A wiring member for supplying voltage to the first individual electrode, the first common electrode, the second individual electrode, and the second common electrode, The first individual electrode and the first individual wiring electrically connect the wiring member, A first common wiring that electrically connects the first common electrode and the wiring member, A second individual wiring that electrically connects the second individual electrode and the wiring member, The second common electrode and the second common wiring electrically connect the wiring member, The wiring member and the first common wiring are electrically connected at a position shifted to one side along the first direction from the center of the first and second pressure chamber rows in the first direction. The liquid discharge head is characterized in that the wiring member and the second common wiring are electrically connected at a position shifted to the other side along the first direction from the center of the first and second pressure chamber rows in the first direction.

2. The wiring member and the first common wiring are electrically connected at a position on one side of the end of the first and second pressure chamber rows. The liquid discharge head according to claim 1, characterized in that the wiring member and the second common wiring are electrically connected at a position on the other side of the other end of the first and second pressure chamber rows.

3. The first common wiring is provided such that the wiring resistance increases as it moves along the first direction from one side to the other side. The liquid dispensing head according to claim 1 or 2, characterized in that the second common wiring is provided such that the wiring resistance increases as it moves along the first direction from the other side to the one side.

4. The first common wiring is provided such that its width in the second direction decreases as it moves along the first direction from one side to the other side. The liquid dispensing head according to claim 3, characterized in that the second common wiring is provided such that its width in the second direction decreases as it moves along the first direction from the other side to the one side.

5. The first common wiring is provided such that, as it extends along the first direction from one side to the other side, the width in the third direction intersecting both the first and second directions decreases. The liquid dispensing head according to claim 3 or 4, characterized in that the second common wiring is provided such that its width in the third direction decreases as it moves along the first direction from the other side to the one side.

6. The first common wiring is provided such that the wiring resistance decreases as it moves along the first direction from one side to the other side. The liquid dispensing head according to claim 1 or 2, characterized in that the second common wiring is provided such that the wiring resistance decreases as it moves along the first direction from the other side to the one side.

7. The first common wiring is provided such that its width in the second direction increases as it moves along the first direction from one side to the other side. The liquid dispensing head according to claim 6, characterized in that the second common wiring is provided such that its width in the second direction increases as it moves along the first direction from the other side to the one side.

8. The first common wiring is provided such that, as it extends along the first direction from one side to the other side, the width in the third direction intersecting both the first and second directions increases. The liquid dispensing head according to claim 6 or 7, characterized in that the second common wiring is provided such that its width in the third direction increases as it moves along the first direction from the other side to the one side.

9. The liquid discharge head according to any one of claims 1 to 8, characterized in that the first individual wiring and the second individual wiring are provided in a range that overlaps with the first and second pressure chambers in the first direction.

10. A common supply channel that communicates with the plurality of first pressure chambers in common and supplies liquid, A liquid discharge head according to any one of claims 1 to 9, further comprising a common discharge channel that communicates in common with the plurality of second pressure chambers and discharges liquid.

11. The first common electrode and the wiring member are electrically connected, and a third common wiring, which is different from the first common wiring, The second common electrode and the wiring member are electrically connected, and a fourth common wiring, which is different from the second common wiring, is provided. The wiring member and the third common wiring are electrically connected at a position shifted to the other side along the first direction from the center of the first and second pressure chamber rows in the first direction. The liquid discharge head according to any one of claims 1 to 10, characterized in that the wiring member and the fourth common wiring are electrically connected at a position shifted to one side along the first direction from the center of the first and second pressure chamber rows in the first direction.

12. The third common wiring is electrically connected to the first common electrode at a position closer to the second pressure chamber row than the first common wiring in the second direction, The liquid discharge head according to claim 11, characterized in that the fourth common wiring is electrically connected to the second common electrode at a position closer to the first pressure chamber row than the second common wiring in the second direction.

13. The first common wiring and the third common wiring are electrically connected. The liquid dispensing head according to claim 12, wherein the second common wiring and the fourth common wiring are electrically connected.

14. The third common wiring is electrically connected to the first common electrode at a position closer to the second pressure chamber row than the first common wiring in the second direction, The fourth common wiring is electrically connected to the second common electrode at a position further away from the first pressure chamber row than the second common wiring in the second direction. The first common wiring and the fourth common wiring are electrically connected. The liquid dispensing head according to claim 11, characterized in that the second common wiring and the third common wiring are electrically connected.

15. A liquid dispensing head, A first pressure chamber row in which multiple first pressure chambers are arranged in a first direction, Multiple second pressure chambers are arranged in the first direction, and a row of second pressure chambers is provided at different positions in a second direction intersecting the first direction and the first pressure chambers. A plurality of first nozzles, each communicating with the plurality of first pressure chambers, are arranged in a first nozzle row in the first direction, A plurality of second nozzles, each communicating with the plurality of second pressure chambers, are arranged in a row of second nozzles in the first direction, A first piezoelectric element provided corresponding to the plurality of first pressure chambers, A first individual electrode is electrically connected to the first piezoelectric element and is provided individually for each of the plurality of first pressure chambers, A first common electrode is electrically connected to the first piezoelectric element and is provided in common to the plurality of first pressure chambers, A second piezoelectric element provided corresponding to the plurality of second pressure chambers, A second individual electrode is electrically connected to the second piezoelectric element and is provided individually for each of the plurality of second pressure chambers, A second common electrode is electrically connected to the second piezoelectric element and is provided in common to the plurality of second pressure chambers, A wiring member for supplying voltage to the first individual electrode, the first common electrode, the second individual electrode, and the second common electrode, The first individual electrode and the first individual wiring electrically connect the wiring member, A first common wiring that electrically connects the first common electrode and the wiring member, A second individual wiring that electrically connects the second individual electrode and the wiring member, A second common wiring that electrically connects the second common electrode and the wiring member, The first common electrode and the wiring member are electrically connected, and a third common wiring, which is different from the first common wiring, The second common electrode and the wiring member are electrically connected, and a fourth common wiring, which is different from the second common wiring, is provided. The wiring member and the first common wiring are electrically connected at a position shifted to one side along the first direction from the center of the first and second pressure chamber rows in the first direction. The wiring member and the second common wiring are electrically connected at a position shifted to the other side along the first direction from the center of the first and second pressure chamber rows in the first direction. The wiring member and the third common wiring are electrically connected at a position shifted to the other side along the first direction from the center of the first and second pressure chamber rows in the first direction. The wiring member and the fourth common wiring are electrically connected at a position shifted to one side along the first direction from the center of the first and second pressure chamber rows in the first direction. A liquid dispensing head characterized by the following features.

16. A liquid dispensing head according to any one of claims 1 to 15, A liquid dispensing device characterized by having a control unit that controls the dispensing operation from the liquid dispensing head.

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