Head chip, liquid ejection head, and liquid ejection apparatus

Abstract

The present disclosure provides a head chip, a liquid ejection head, and a liquid ejection apparatus. The head chip includes: a first nozzle that ejects liquid; a second nozzle that ejects liquid; a first pressure chamber that communicates with the first nozzle; a second pressure chamber that communicates with the first nozzle; a third pressure chamber that communicates with the second nozzle; a fourth pressure chamber that communicates with the second nozzle; a first piezoelectric body that generates pressure in the first pressure chamber; a second piezoelectric body that generates pressure in the second pressure chamber; a third piezoelectric body that generates pressure in the third pressure chamber; a fourth piezoelectric body that generates pressure in the fourth pressure chamber; a first independent electrode connected to the first piezoelectric body; a second independent electrode connected to the second piezoelectric body; a third independent electrode connected to the third piezoelectric body; a fourth independent electrode connected to the fourth piezoelectric body; a first common electrode commonly connected to the first piezoelectric body and the third piezoelectric body; and a second common electrode commonly connected to the second piezoelectric body and the fourth piezoelectric body, independently of the first common electrode.

Description

Technical Field

[0001] This disclosure relates to a head chip, a liquid jetting head, and a liquid jetting device. Background Technology

[0002] In liquid jetting devices, such as inkjet printers that use piezoelectric technology, a pressure chamber connected to the nozzle and a piezoelectric element that generates pressure variations in the pressure chamber are typically included. Here, for example, as disclosed in Patent Document 1, multiple pressure chambers and multiple piezoelectric elements are sometimes provided for a single nozzle.

[0003] The head unit described in Patent Document 1 includes a first pressure chamber and a second pressure chamber communicating with a nozzle, a first piezoelectric element corresponding to the first pressure chamber, a second piezoelectric element corresponding to the second pressure chamber, and a wiring board connected to a switching circuit. Here, the first and second piezoelectric elements each include a first electrode, a second electrode, and a piezoelectric layer sandwiched between the two electrodes. Furthermore, the first electrode of both the first and second piezoelectric elements is a common electrode connected to a common power supply line. In contrast, the second electrodes of both the first and second piezoelectric elements are independent electrodes. Independent drive signals are transmitted from the switching circuit to the respective second electrodes of the first and second piezoelectric elements.

[0004] However, in the past, for example as disclosed in Patent Document 2, the natural vibration frequency of the vibrating part formed by the piezoelectric element was sometimes measured. The method described in Patent Document 2 is based on the result of measuring the impedance when a specific Sin wave is input to the piezoelectric actuator using a measuring instrument such as an impedance analyzer, and then measuring the natural vibration frequency of the vibrating part formed by the piezoelectric actuator.

[0005] In Patent Document 1, each drive signal is transmitted from a switching circuit to a piezoelectric element corresponding to one of the two pressure chambers connected to a common nozzle. This increases the number of switching elements, potentially leading to a larger wiring board housing the switching circuit or excessive heating of the switching circuit. Therefore, it is possible to miniaturize the wiring board and suppress heating of the switching circuit by transmitting a common drive signal to the independent electrodes of the two piezoelectric elements corresponding to the common nozzle.

[0006] However, in Patent Document 1, the two piezoelectric elements corresponding to the shared nozzle are connected to the same shared electrode, and the power supply line for supplying power to this shared electrode is also shared. Therefore, in Patent Document 1, with a structure that transmits a shared drive signal to the independent electrodes of the two piezoelectric elements corresponding to the shared nozzle, it is impossible to use the method described in Patent Document 2 to measure the inherent vibration frequencies of the two vibrating parts corresponding to the shared nozzle separately. Therefore, in this case, it is impossible to determine whether a characteristic difference exists between the two vibrating parts. Under the above circumstances, it is desirable to achieve miniaturization of the head chip, suppression of heat generation, and performance testing for each pressure chamber in a structure that provides multiple pressure chambers for a single nozzle.

[0007] Patent Document 1: Japanese Patent Application Publication No. 2020-104456

[0008] Patent Document 2: Japanese Patent Application Publication No. 2018-51844 Summary of the Invention

[0009] To address the above-mentioned issues, the preferred embodiment of the present disclosure includes a head chip comprising: a first nozzle for spraying liquid; a second nozzle for spraying liquid; a first pressure chamber communicating with the first nozzle; a second pressure chamber communicating with the first nozzle; a third pressure chamber communicating with the second nozzle; a fourth pressure chamber communicating with the second nozzle; a first piezoelectric body that generates pressure in the first pressure chamber; a second piezoelectric body that generates pressure in the second pressure chamber; a third piezoelectric body that generates pressure in the third pressure chamber; a fourth piezoelectric body that generates pressure in the fourth pressure chamber; a first independent electrode connected to the first piezoelectric body; a second independent electrode connected to the second piezoelectric body; a third independent electrode connected to the third piezoelectric body; a fourth independent electrode connected to the fourth piezoelectric body; a first common electrode connected to both the first and third piezoelectric bodies in a shared manner; and a second common electrode independent of the first common electrode and connected to both the second and fourth piezoelectric bodies in a shared manner.

[0010] The liquid jetting head according to the preferred embodiment of this disclosure comprises: a head chip as described above; and a relay substrate connected to the head chip.

[0011] The liquid injection device according to the preferred embodiment of this disclosure includes: a liquid injection head of the aforementioned manner; and a wiring component connected to the liquid injection head. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the liquid injection device according to the first embodiment.

[0013] Figure 2 This is a block diagram of the head unit of the liquid injection device according to the first embodiment.

[0014] Figure 3 This is an exploded perspective view of the liquid injection head according to the first embodiment.

[0015] Figure 4 This is a diagram used to illustrate the operation of the drive circuit.

[0016] Figure 5 This is a cross-sectional view of the head chip according to the first embodiment.

[0017] Figure 6 This is a cross-sectional view of a piezoelectric element.

[0018] Figure 7 This is a schematic plan view for illustrating the piezoelectric element in the first embodiment.

[0019] Figure 8 This is a schematic diagram used to illustrate the wiring board in the first embodiment.

[0020] Figure 9 This is a schematic diagram used to illustrate the drive circuit in the first embodiment.

[0021] Figure 10 This is a schematic diagram used to illustrate the relay substrate in the first embodiment.

[0022] Figure 11 This diagram illustrates the performance testing of the head chip.

[0023] Figure 12 This is a schematic plan view used to illustrate the piezoelectric element in the second embodiment.

[0024] Figure 13 This is a schematic diagram used to illustrate the wiring board in the second embodiment.

[0025] Figure 14 This is a schematic plan view for illustrating the piezoelectric element in the third embodiment. Detailed Implementation

[0026] Hereinafter, preferred embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that the dimensions and scales of the various parts in the drawings may differ appropriately from actual dimensions, and some parts may be shown schematically for ease of understanding. Furthermore, the scope of this disclosure is not limited to these embodiments unless specifically limited in the following description.

[0027] For convenience, the following explanation will use intersecting X-axis, Y-axis, and Z-axis as appropriate. Hereinafter, one direction along the X-axis is designated X1, and the opposite direction is designated X2. Similarly, opposite directions along the Y-axis are designated Y1 and Y2. Furthermore, opposite directions along the Z-axis are designated Z1 and Z2. Additionally, the observation along the Z1 or Z2 direction will sometimes be referred to as "planar observation."

[0028] Here, typically, the Z-axis is a vertical axis, and the Z2 direction corresponds to the downward direction in the vertical direction. However, the Z-axis may not be a vertical axis, and may be inclined relative to the vertical axis. In addition, the X-axis, Y-axis, and Z-axis are typically orthogonal to each other, but are not limited to this; for example, they may intersect at an angle between 80° and 100°.

[0029] 1. First Implementation Method

[0030] 1-1. Liquid injection device

[0031] Figure 1 This is a schematic diagram of the liquid jetting apparatus 100 according to the first embodiment. The liquid jetting apparatus 100 is an inkjet printing apparatus that jets an ink, an example of a liquid, such as ink, as droplets onto a medium M. The liquid jetting apparatus 100 of this embodiment is a so-called row-type printing apparatus in which a plurality of nozzles for jetting ink are distributed across the entire width direction of the medium M. The medium M is typically printing paper. However, the medium M is not limited to printing paper, and may be any printing material such as resin film or cloth.

[0032] like Figure 1 As shown, the liquid injection device 100 includes a liquid container 10, a control unit 20, a conveying mechanism 30, multiple head units 40, and a circulation mechanism 50.

[0033] Liquid container 10 stores ink. Specific examples of liquid container 10 include, for instance, a detachable box relative to the liquid dispensing device 100, a bag-shaped ink pouch formed of a flexible film, and an ink canister capable of being replenished. Furthermore, the type of ink stored in liquid container 10 can be any type. The ink in liquid container 10 is transferred to auxiliary tank 51 via pump 11, which is disposed between liquid container 10 and auxiliary tank 51 (described later).

[0034] The control unit 20 controls the operation of various elements of the liquid injection device 100. The control unit 20 includes, for example, processing circuits such as a CPU (Central Processing Unit) or FPGA (Field Programmable Gate Array), and storage circuits such as semiconductor memory. Various programs and data are stored in these storage circuits. The processing circuit executes the programs and appropriately uses the data to achieve various controls.

[0035] The conveying mechanism 30 conveys the medium M under the control of the control unit 20. Figure 1 In the example shown, the conveying mechanism 30 conveys the medium M along the Y1 direction. The conveying mechanism 30 includes, for example, a conveying roller that is elongated along the X-axis and a motor that rotates the conveying roller. In addition, the conveying mechanism 30 is not limited to a structure using a conveying roller; for example, it can also be a structure using a roller or a seamless belt that conveys the medium M while it is being attracted to the outer peripheral surface by electrostatic force or the like.

[0036] Multiple head units 40, under the control of the control unit 20, spray ink supplied from the liquid container 10 via the circulation mechanism 50 from each of the multiple nozzles onto the medium M.

[0037] exist Figure 1 In the example shown, multiple head units 40 each have a liquid ejection head 41 and a drive module 42. The multiple liquid ejection heads 41 constitute a row head with multiple nozzles distributed across the entire range of the medium M in the X-axis direction, ejecting ink in the Z2 direction. The drive module 42 drives the liquid ejection heads 41 based on image information IP from the control unit 20. The image information IP is information based on data representing the image to be printed. Furthermore, the number of head units 40 is not limited to... Figure 1 The example shown represents any number of such numbers.

[0038] The circulation mechanism 50 is a mechanism that supplies ink to each head unit 40 and recovers ink discharged from each head unit 40 for resupply to the head unit 40. The circulation mechanism 50 includes, for example, a secondary tank 51 for storing ink supplied from the liquid container 10, a supply channel 53 for supplying ink from the secondary tank 51 to the head unit 40, a recovery channel 54 for recovering ink from the head unit to the secondary tank, and a pump 52 for transferring ink to these channels. Through the operation of the circulation mechanism 50, the increase in ink viscosity can be suppressed or the retention of air bubbles within the ink can be reduced.

[0039] 1-2. Head Unit

[0040] Figure 2 This is a block diagram of the head unit 40 of the liquid injection device 100 according to the first embodiment. As described above, the head unit 40 has a liquid injection head 41 and a drive module 42. The liquid injection head 41 and the drive module 42 are electrically connected to each other via a wiring component 43. Figure 3 This is an exploded perspective view of the liquid injection head 41. Additionally, in... Figure 3 The diagram also shows wiring component 43.

[0041] Wiring component 43 is a flexible component used to electrically connect the liquid injection head 41 and the drive module 42 to each other. Specifically, wiring component 43 is, for example, a flexible printed circuit board (FPC) or a flexible flat cable (FFC). Furthermore, the structure for electrically connecting the liquid injection head 41 and the drive module 42 is not limited to a structure using wiring component 43; for example, it can be a structure using B-to-B (Board to Board) connectors, or a structure using both B-to-B connectors and FPC, or B-to-B connectors and FFC.

[0042] like Figure 2 As shown, the drive module 42 includes a control circuit 42a, a power supply circuit 42b, drive signal output circuits 42c_1 to 42c_m, and a conversion circuit 42d. Furthermore, m is a natural number greater than 2, and corresponds to the number of head chips 41a (described later) mounted on the liquid injection head 41. Additionally, hereinafter, the drive signal output circuits 42c_1 to 42c_m are sometimes referred to as drive signal output circuits 42c. Furthermore, hereinafter, the symbols corresponding to the elements of the drive signal output circuits 42c_1 to 42c_m are appended with the suffixes "_1" to "_m".

[0043] The power supply circuit 42b receives power from a commercial power supply not shown in the diagram and generates a power supply potential GVDD, a ground potential GND, a high-potential side power supply potential VHV, and a low-potential side power supply potential VDD. These potentials are all constant potentials. Specifically, for example, the power supply potential GVDD is approximately 7.5V, the ground potential GND is approximately 0V, the power supply potential VHV is approximately 42V, and the power supply potential VDD is approximately 3.3V. These potentials are supplied to each of the drive signal output circuits 42c_1 to 42c_m. In addition, the ground potential GND, the power supply potential VHV, and the power supply potential VDD are supplied to the liquid injection head 41 via the wiring component 43, in addition to being supplied to the drive signal output circuits 42c_1 to 42c_m respectively.

[0044] The control circuit 42a is composed of a processing circuit such as a CPU or FPGA, and outputs various data and signals based on the image information IP input from the control unit 20.

[0045] Here, control circuit 42a generates printing data signals SI_1 to SI_m, latch signal LAT, conversion signal ch, and clock signal SCK based on image information IP. Each of these generated signals is input to conversion circuit 42d. Printing data signals SI_1 to SI_m are digital signals used to specify the type of operation of the piezoelectric element 400 (described later). Specifically, printing data signals SI_1 to SI_m specify the type of operation of the piezoelectric element 400 by specifying whether drive signals COM_A and COM_B are supplied to the piezoelectric element 400. Latch signal LAT and conversion signal CH are used in conjunction with printing data signals SI_1 to SI_m to determine the driving timing of the piezoelectric element 400. The timing of the pulses contained in these signals is determined based on clock signal SCK. Furthermore, hereinafter, printing data signals SI_1 to SI_m are sometimes referred to as printing data signals SI. Additionally, drive signals COM_A and COM_B are sometimes referred to as drive signals COM.

[0046] The conversion circuit 42d converts the printed data signals SI_1 to SI_m, the latch signal LAT, the conversion signal CH, and the clock signal SCK into differential signals such as LVDS (Low Voltage Differential Signaling), thereby generating a data signal DATA. The data signal DATA is input to the liquid injection head 41 via the wiring component 43. In addition, the data signal DATA is not limited to LVDS. For example, it can be a differential signal with high-speed transmission methods such as LVPECL (Low Voltage Positive Emitter Coupled Logic) or CML (Current Mode Logic), or it can be a signal in which some or all of the printed data signals SI_1 to SI_m, the latch signal LAT, the conversion signal CH, and the clock signal SCK are set to single-ended.

[0047] In addition, the control circuit 42a generates drive data dA and dB. The drive data dA and dB are respectively input to each of the drive signal output circuits 42c_1 to 42c_m.

[0048] The drive signal output circuit 42c generates a drive signal COM_A based on drive data dA and a drive signal COM_B based on drive data dB. Ground potential GND, power supply potential VHV, and power supply potential VDD are used in this generation. For example, after converting drive data dA from a digital signal to an analog signal, the drive signal output circuit 42c generates drive signal COM_A by amplifying the analog signal at the D stage. Similarly, after converting drive data dB from a digital signal to an analog signal, the drive signal output circuit 42c generates drive signal COM_B by amplifying the analog signal at the D stage. Drive signals COM_A and COM_B are respectively input to the liquid injection head 41 via wiring component 43.

[0049] In addition to generating drive signals COM_A and COM_B, the drive signal output circuit 42c also generates a bias potential VBS. The power supply potential GVDD is used in this generation. The bias potential VBS is a constant potential. The specific potential of the bias potential VBS is not particularly limited; for example, it can be a constant potential of approximately 5.5V or 6V, or it can be a ground potential. The bias potential VBS is input to the liquid injection head 41 via the wiring component 43. Furthermore, "constant potential" includes cases where a constant potential is considered after taking into account various variations such as potential variations caused by the operation of peripheral circuits, potential variations caused by deviations of circuit components, and potential variations caused by the temperature characteristics of circuit components.

[0050] The liquid injection head 41 has a recovery circuit 41b and head chips 41a_1 to 41a_m. For example... Figure 3 As shown, the liquid injection head 41 of this embodiment has six head chips 41a. Furthermore, hereinafter, each head chip 41a_1 to 41a_m will sometimes be referred to as head chip 41a.

[0051] The restoration circuit 41b restores the data signal DATA into a single-ended signal and separates it into signals corresponding to the head chips 41a_1 to 41a_m respectively.

[0052] Specifically, the restoration circuit 41b restores the data signal DATA to generate printing data signals SI_1 to SI_m, latch signals LAT, conversion signals ch, and clock signals SCK. Furthermore, the restoration circuit 41b separates the printing data signals SI_1 to SI_m, latch signals LAT, conversion signals ch, and clock signals SCK for each head chip 41a. These separated signals are then input to each head chip 41a. Here, the printing data signals SI_1 to SI_m correspond to head chips 41a_1 to 41a_m, respectively.

[0053] The recovery circuit 41b described above is mounted on the relay substrate 440. The relay substrate 440 is connected to the drive module 42 via the wiring component 43. Further details regarding the relay substrate 440 will be provided later. Figure 10 Let me explain.

[0054] Here, drive signals COM_A, COM_B, bias potential VBS, ground potential GND, power supply potential VHV, and power supply potential VDD are supplied from drive module 42 to each head chip 41a_1 to 41a_m via relay substrate 440. Furthermore, as described above, print data signal SI, latch signal LAT, conversion signal CH, and clock signal SCK are input from recovery circuit 41b to each head chip 41a_1 to 41a_m.

[0055] like Figure 3 As shown, the liquid jet head 41 includes a fixing plate 470, head chips 41a_1 to 41a_m, a holder 450, a relay substrate 440, and a flow channel structure 460, which are stacked in sequence. These stacked components constituting the liquid jet head 41 are fixed by fasteners such as adhesives or screws (not shown).

[0056] The fixing plate 470 has six openings 471 extending through the fixing plate 470 along the Z2 direction. Moreover, the six head chips 41a are fixed to the surface of the fixing plate 470 facing the Z1 direction such that the nozzle substrate 413 of the head chip 41a protrudes from the six openings 471 respectively.

[0057] The holder 450 is located on the Z1 direction side of the head chip 41a and houses the head chip 41a between it and the fixing plate 470. Two inlet portions 451 and two outlet portions 452 are provided on the Z1 direction-facing surface of the holder 450. The two inlet portions 451 communicate with a first supply channel hole (not shown) formed on the Z2 direction-facing surface of the holder 450 via a holder supply channel (not shown) formed inside the holder 450. This first supply channel hole is connected to the supply port H1 of the head chip 41a (described later). Furthermore, the two outlet portions 452 communicate with a first discharge channel hole (not shown) formed on the Z2 direction-facing surface of the holder 450 via a holder discharge channel (not shown) formed inside the holder 450. This first discharge channel hole is connected to the discharge port H2 of the head chip 41a (described later). Additionally, the holder 450 has six openings 453 extending along the Z1 direction. The wiring substrate 430 of each of the six head chips 41a is inserted into the six openings 453.

[0058] The relay substrate 440 is located in the Z1 direction of the holder 450. The relay substrate 440 has a connector 445 for connecting one end of a wiring component 43, which is used to electrically connect the drive module 42 and the liquid injection head 41. Furthermore, four openings 447 and two cutouts 448 are formed on the relay substrate 440. The wiring substrates 430 of head chips 41a_2 to 41a_5 are inserted into the four openings 447. Moreover, the respective wiring substrates 430 of head chips 41a_2 to 41a_5 inserted into the four openings 447 are electrically connected to the relay substrate 440 by soldering or the like. Furthermore, the wiring substrate 430 of head chip 41a_1 passes through one of the cutouts 448, and the wiring substrate 430 of head chip 41a_6 passes through the other of the cutouts 448. Furthermore, the wiring substrates 430 of the head chips 41a_1 and 41a_6, which pass through the two cutouts 448 respectively, are electrically connected to the relay substrate 440 by soldering or the like.

[0059] The flow channel structure 460 has two inlet portions 461 and two outlet portions 462 protruding in the Z1 direction on its Z1-oriented surface. The two inlet portions 461 communicate with, respectively, a second supply flow channel hole (not shown) formed on the Z2-oriented surface of the flow channel structure 460 via a flow channel (not shown) formed inside the flow channel structure 460. This second supply flow channel hole is connected to the inlet portion 451 of the retainer 450. A supply flow channel 53, for example, formed of a tube, is connected to each of the two inlet portions 461. Furthermore, the two outlet portions 472 communicate with, respectively, a second discharge flow channel hole (not shown) formed on the Z2-oriented surface of the flow channel structure 460 via a flow channel (not shown) formed inside the flow channel structure 460. This second discharge flow channel hole is connected to the outlet portion 452 of the retainer 450. A recovery flow channel 54, for example, formed of a tube, is connected to each of the two outlet portions 462.

[0060] Furthermore, a through hole 463 extending along the Z1 direction is formed in the flow channel structure 460. A wiring component 43, which is electrically connected to the relay substrate 440, is inserted through the through hole 463. In addition, a filter or the like may be provided inside the flow channel structure 460 to capture foreign matter contained in the ink flowing in the flow channel formed inside the flow channel structure 460.

[0061] Head chips 41a_1 to 41a_m each have drive circuits 410_1 to 410_m for driving the piezoelectric element 400 (piezoelectric body). The drive circuit 410 will be described below. Furthermore, detailed information about head chip 41a will be provided later based on… Figures 5 to 8This will be explained in detail below. Furthermore, in the following, drive circuits 410_1 to 410_m will sometimes be referred to as drive circuit 410.

[0062] The drive circuit 410 has multiple switching elements 410sw, which switch whether to supply drive signals COM_A and COM_B to the piezoelectric element 400 based on the clock signal SCK, the printed data signal SI, the conversion signal CH, and the latch signal LAT. Here, the actual waveform supplied to the piezoelectric element 400 in the waveforms of the drive signals COM_A and COM_B is the drive signal VOUT. Furthermore, the drive signal VOUT is supplied to one electrode (the independent electrode 401 described later) of a pair of electrodes of the piezoelectric element 400, and a bias potential VBS is supplied to the other electrode (the common electrode 403 described later). Additionally, an example of the conversion signal CH, the latch signal LAT, and the drive signals COM_A and COM_B will be provided later. Figure 4 Let me explain.

[0063] The aforementioned drive circuit 410 is mounted on the wiring board 430. The wiring board 430 electrically connects multiple piezoelectric elements 400 to the relay board 440. Further details regarding the wiring board 430 will be provided later. Figure 8 Let me explain.

[0064] As described above, the liquid injection device 100 includes a liquid injection head 41 and a wiring component 43 connected to the liquid injection head 41. Here, as mentioned earlier, the liquid injection head 41 includes at least one head chip 41a and a relay substrate 440 connected to the head chip 41a.

[0065] 1-3. Operation of the drive circuit 410

[0066] Figure 4 This is a diagram used to illustrate the operation of the drive circuit 410. (See diagram below.) Figure 4 As shown, the latch signal LAT includes a pulse PlsL for specifying a unit period Tu. Figure 4 In the example shown, the unit period Tu is defined as the period from the rising edge of pulse PlsL to the rising edge of the next pulse PlsL. The unit period Tu corresponds to the printing cycle in which dots are formed on the medium M by ink ejected from nozzle N. That is, the unit period Tu corresponds to the control cycle of the aforementioned drive circuit 410.

[0067] The conversion signal CH includes a pulse PlsC for dividing the unit period Tu into control period Tu1 and control period Tu2. Control period Tu1 and control period Tu2 are sequentially arranged as time elapses. Control period Tu1 is, for example, the period from the rising edge of pulse PlsL to the rising edge of the initial pulse PlsC. Control period Tu2 is, for example, the period from the rising edge of the initial pulse PlsC to the rising edge of the subsequent second pulse PlsC. Additionally, although in Figure 4 In the example shown, control periods Tu1 and Tu2 are of equal length, but this is not a limitation; control periods Tu1 and Tu2 can also be of different lengths. Furthermore, the switching signal CH can divide a unit period into more than three control periods.

[0068] The drive signal COM_A has pulse PA1 set during control period Tu1 and pulse PA2 set during control period Tu2. The drive signal COM_B has pulse PB1 set during control period Tu1 and pulse PB2 set during control period Tu2.

[0069] exist Figure 4 In the example shown, pulses PA1, PA2, and PB2 are potential pulses that drive the piezoelectric element 400 by causing pressure variations in the pressure chambers Ca and Cb (described later) that result in ink being ejected from the nozzle N (described later). In contrast, pulse PB1 is a potential pulse that drives the piezoelectric element 400 by causing pressure variations in the pressure chambers Ca and Cb (described later) that do not result in ink being ejected from the nozzle N (described later). Furthermore, the waveforms of pulses PA1, PA2, PB1, and PB2 are not limited to... Figure 4 The example shown is an arbitrary waveform. Furthermore, the pulse PB1 can also be a potential pulse that drives the piezoelectric element 400 in such a way that the pressure chambers Ca and Cb (described later) generate pressure variations of such intensity that ink is ejected from the nozzle N (described later).

[0070] The pulses PA1, PA2, PB1, and PB2 mentioned above are appropriately selected for each unit period Tu and used in the drive signal VOUT. This allows for adjustment of the amount of ink ejected from nozzle N, or for micro-vibration of the ink within nozzle N without ejecting ink from nozzle N.

[0071] 1-4. Head chip

[0072] Figure 5This is a cross-sectional view of the head chip 41a according to the first embodiment. For convenience, the following description will use the V-axis and W-axis in addition to the X-axis, Y-axis, and Z-axis. Furthermore, one direction along the V-axis is the V1 direction, and the direction opposite to the V1 direction is the V2 direction. Similarly, the opposite directions along the W-axis are the W1 direction and the W2 direction.

[0073] Here, the V-axis is the axis along the arrangement direction of the plurality of nozzles N, i.e., the nozzle array direction DN, as described later, and is the axis after rotating the Y-axis around the Z-axis by a predetermined angle. The W-axis is the axis after rotating the X-axis around the Z-axis by the predetermined angle. Therefore, although the V-axis and W-axis are typically orthogonal to each other, they are not limited to this; for example, they may intersect at an angle in the range of 80° to 100°. Furthermore, the predetermined angle, i.e., the angle between the V-axis and the Y-axis or the angle between the W-axis and the X-axis, is, for example, in the range of 40° to 60°.

[0074] like Figure 5 As shown, the head chip 41a includes a flow channel substrate 411, a pressure chamber substrate 412, a nozzle substrate 413, a vibration absorber 414, a vibrating plate 415, a cover 416, a housing 417, multiple piezoelectric elements 400, and a wiring substrate 430. Here, the pressure chamber substrate 412 and the vibrating plate 415 constitute an actuator substrate 420 that carries multiple piezoelectric elements 400.

[0075] The flow channel substrate 411 and the pressure chamber substrate 412 are sequentially stacked along the Z1 direction to form multiple independent flow channels P for supplying ink to multiple nozzles N. The multiple independent flow channels P are arranged in the direction along the V-axis. Each of the multiple independent flow channels P is connected to a different nozzle N and has a pressure chamber Ca, a pressure chamber Cb, a nozzle flow channel Nf, a supply flow channel Ra1, a discharge flow channel Ra2, a first longitudinal flow channel Na1, and a second longitudinal flow channel Na2. Hereinafter, each pressure chamber Ca and Cb will sometimes be referred to as pressure chamber C.

[0076] In the region located in the Z1 direction relative to the laminate formed by the flow channel substrate 411 and the pressure chamber substrate 412, a vibrating plate 415, multiple piezoelectric elements 400, covers 416, 417, and a wiring substrate 430 are provided. On the other hand, in the region located in the Z2 direction relative to the laminate, a nozzle substrate 413 and a vibration absorber 414 are provided. The various elements of the head chip 41a are plate-shaped components that are elongated in a direction generally along the V-axis, and are bonded to each other, for example, by an adhesive. A plurality of nozzles N are provided on the nozzle substrate 413. The plurality of nozzles N are arranged in a direction along the V-axis (the nozzle row direction DN described later). The plurality of nozzles N each penetrate the nozzle substrate 413 and are through holes through which ink passes.

[0077] Multiple pressure chambers Ca and multiple pressure chambers Cb are provided in the pressure chamber substrate 412. The multiple pressure chambers Ca are arranged in the direction along the V-axis. The multiple pressure chambers Cb are arranged in the direction along the V-axis relative to the multiple pressure chambers Ca in the W1 direction. Here, the pressure chambers Ca and Cb corresponding to the common nozzle N are arranged in the direction along the W-axis, and when viewed in the ejection direction of ink from the nozzle N, i.e., the Z2 direction, the nozzle N is disposed between the pressure chambers Ca and Cb corresponding to the common nozzle N. The pressure chambers Ca and Cb respectively penetrate the pressure chamber substrate 412 and are the gap between the flow channel substrate 411 and the vibrating plate 415.

[0078] The flow channel substrate 411 is provided with spaces R1a, R2a, nozzle flow channel Nf, supply flow channel Ra1 and discharge flow channel Ra2.

[0079] Spaces R1a and R2a are spaces that penetrate the flow channel substrate 411 along the Z-axis. Here, space R1a forms part of the first common liquid chamber R1. In addition, space R2a forms part of the second common liquid chamber R2. On the Z2-facing surface of the flow channel substrate 411, a vibration absorber 414 is provided to close the opening formed by spaces R1a and R2a.

[0080] The vibration absorber 414 is a layered component made of elastic material. The vibration absorber 414 forms part of the wall of the first common liquid chamber R1 and the second common liquid chamber R2, and absorbs pressure fluctuations in the first common liquid chamber R1 and the second common liquid chamber R2.

[0081] The nozzle flow channel Nf is the space that connects pressure chambers Ca and Cb. Figure 5 In the example shown, the nozzle channel Nf has a transverse channel Nf1, a first longitudinal channel Na1, and a second longitudinal channel Na2. The transverse channel Nf1 is a space provided in a groove on the surface of the channel substrate 411 facing the Z2 direction. Here, the nozzle substrate 413 forms part of the wall of the transverse channel Nf1. The first longitudinal channel Na1 and the second longitudinal channel Na2 extend along the Z-axis and are spaces penetrating the channel substrate 411. The first longitudinal channel Na1 connects the pressure chamber Ca to the transverse channel Nf1 and guides the ink from the pressure chamber Ca to the transverse channel Nf1. On the other hand, the second longitudinal channel Na2 connects the pressure chamber Cb to the transverse channel Nf1 and guides the ink from the transverse channel Nf1 to the pressure chamber Cb.

[0082] The supply channel Ra1 and the discharge channel Ra2 extend along the Z-axis and are spaces penetrating the channel substrate 411. The supply channel Ra1 connects the first common liquid chamber R1 to the pressure chamber Ca and supplies ink from the first common liquid chamber R1 to the pressure chamber Ca. Here, one end of the supply channel Ra1 opens on the Z1-oriented surface of the channel substrate 411. In contrast, the other end of the supply channel Ra1 is the upstream end of the independent channel P and opens on the wall of the first common liquid chamber R1 in the channel substrate 411. On the other hand, the discharge channel Ra2 connects the second common liquid chamber R2 to the pressure chamber Cb and discharges ink from the pressure chamber Cb to the second common liquid chamber R2. Here, one end of the discharge channel Ra2 opens on the Z1-oriented surface of the channel substrate 411. In contrast, the other end of the discharge channel Ra2 is the downstream end of the independent channel P and opens on the wall of the second common liquid chamber R2 in the channel substrate 411.

[0083] The vibrating plate 415 is a plate-shaped component capable of elastic vibration. Detailed information about the vibrating plate 415 will follow later. Figure 6 Let me explain.

[0084] On the Z1-oriented surface of the vibrating plate 415, a plurality of piezoelectric elements 400 corresponding to different pressure chambers C are provided. When viewed in planar view, the piezoelectric elements 400 overlap with their corresponding pressure chambers C. The piezoelectric elements 400 are supplied with a drive signal VOUT, causing the vibrating plate 415 to vibrate along with their own deformation. The pressure chambers C expand and contract with this vibration, thereby causing changes in the pressure of the ink within the pressure chambers C.

[0085] The outer casing 417 is used for storing ink. Spaces R1b and R2b are provided within the outer casing 417. Space R1b, together with the aforementioned space R1a, constitutes a first common liquid chamber R1. Furthermore, space R2b, together with the aforementioned space R2a, constitutes a second common liquid chamber R2. Additionally, a supply port H1 and a discharge port H2 are provided on the outer casing 417. The supply port H1 is a conduit communicating with the first common liquid chamber R1 and is connected to the supply flow channel 53 of the aforementioned circulation mechanism 50 via the aforementioned retainer 450 and the flow channel structure 460. Therefore, ink from the circulation mechanism 50 is supplied to the first common liquid chamber R1 via the supply port H1. On the other hand, the discharge port H2 is a conduit communicating with the second common liquid chamber R2 and is connected to the recovery flow channel 54 of the circulation mechanism 50 via the aforementioned retainer 450 and the flow channel structure 460. Therefore, ink in the second common liquid chamber R2 is discharged to the circulation mechanism 50 via the discharge port H2.

[0086] The cover 416 is a plate-shaped component disposed on the Z1-oriented surface of the vibrating plate 415, protecting the multiple piezoelectric elements 400 and strengthening the mechanical strength of the vibrating plate 415. Here, a space is formed between the cover 416 and the vibrating plate 415 to house the multiple piezoelectric elements 400.

[0087] The wiring board 430 is mounted on the Z1-oriented surface of the vibrating plate 415, and is a flexible wiring board such as an FPC (Flexible Printed Circuit) or FFC (Flexible Flat Cable). The aforementioned drive circuit 410 is mounted on the wiring board 430.

[0088] In the head chip 41a with the above structure, the ink is sequentially transferred to the first common liquid chamber R1, the supply channel Ra1, the pressure chamber Ca, the nozzle channel Nf, the pressure chamber Cb, the discharge channel Ra2, and the second common liquid chamber R2 by the operation of the aforementioned circulation mechanism 50. Furthermore, the operation period or timing of the circulation mechanism 50 is arbitrary.

[0089] Furthermore, the piezoelectric elements 400 corresponding to the pressure chambers Ca and Cb, which are connected to the common nozzle N, are simultaneously driven by the drive signal VOUT from the drive circuit 410, thereby causing pressure changes in pressure chambers Ca and Cb, and ink is ejected from the nozzle N along with these pressure changes. Figure 5 In the diagram, dashed arrows are used to indicate the flow of ink when the piezoelectric elements 400 corresponding to both pressure chambers Ca and Cb are driven simultaneously.

[0090] 1-5. Piezoelectric elements and actuator substrates

[0091] Figure 6 This is a cross-sectional view of the piezoelectric element 400. As described above, the actuator substrate 420 includes a pressure chamber substrate 412 having pressure chambers C and a vibrating plate 415. On the Z1-oriented surface of such actuator substrate 420, a piezoelectric element 400 is disposed for each pressure chamber C. The vibrating plate 415 is stacked on the pressure chamber substrate 412.

[0092] Here, in Figure 6 In the example shown, the vibrating plate 415 has a first layer 415a and a second layer 415b, which are stacked sequentially along the Z1 direction. The first layer 415a is, for example, an elastic film made of silicon oxide (SiO2). This elastic film is formed, for example, by thermally oxidizing one side of a single-crystal substrate. The second layer 415b is, for example, an insulating film made of zirconium oxide (ZrO2). This insulating film is formed, for example, by sputtering to form a zirconium layer, and then by thermally oxidizing the layer.

[0093] Furthermore, the first layer 415a is not limited to silicon oxide; for example, it may be composed of other elastic materials such as silicon monomers. The constituent material of the second layer 415b is not limited to zirconium oxide; for example, it may be other insulating materials such as silicon nitride. Additionally, other layers such as metal oxides may be interposed between the first layer 415a and the second layer 415b. Furthermore, part or all of the vibrating plate 415 may be integrally formed of the same material as the pressure chamber substrate 412. Alternatively, the vibrating plate 415 may be composed of a single layer of material.

[0094] Additionally, the vibrating plate 415 or at least a portion thereof (e.g., the second layer 415b) may also be integrally formed with the pressure chamber substrate 412. That is, in this specification, "the vibrating plate 415 is laminated on the pressure chamber substrate 412" means not only that the vibrating plate 415 or a portion thereof is laminated on the pressure chamber substrate 412, which is a material different from the vibrating plate 415 or a portion thereof, and is fixed relative to the pressure chamber substrate 412, but also that the vibrating plate 415 or a portion thereof is integrally formed of the same material as the pressure chamber substrate 412.

[0095] The piezoelectric element 400 has an independent electrode 401, a piezoelectric body 402 and a common electrode 403, which are stacked sequentially along the Z1 direction.

[0096] Additionally, other layers, such as those used to improve adhesion, may be appropriately placed between the layers of the piezoelectric element 400 or between the piezoelectric element 400 and the vibrating plate 415. Furthermore, a seed layer may be provided between the individual electrode 401 and the piezoelectric body 402. This seed layer has the function of improving the orientation of the piezoelectric body 402 during its formation. This seed layer may be made of, for example, titanium (Ti), or an oxide with a perovskite structure, such as Pb(Fe,Ti)O3.

[0097] Individual electrodes 401 are mounted on actuator substrate 420 and configured separately from each other for each piezoelectric element 400. A drive signal VOUT is supplied to the individual electrodes 401. Individual electrodes 401 may have, for example, a first layer made of titanium (Ti), a second layer made of platinum (Pt), and a third layer made of iridium (Ir), which are sequentially stacked along the Z1 direction. Individual electrodes 401 are formed, for example, by known film deposition techniques such as sputtering, and by known processing techniques such as photolithography and etching.

[0098] Furthermore, the structure of the independent electrode 401 is not limited to the aforementioned example. For example, either the aforementioned second or third layer may be omitted, or a layer made of iridium may be further provided between the aforementioned first and second layers. Alternatively, a layer made of an electrode material other than iridium and platinum may be used instead of the second and third layers, or a layer made of an electrode material other than iridium and platinum may be used in addition to the second and third layers. Examples of such electrode materials include aluminum (Al), nickel (Ni), gold (Au), and copper (Cu), among others. One of these metals may be used alone, or two or more may be used in combination in a laminated or alloyed manner.

[0099] A piezoelectric element 402 is disposed between an individual electrode 401 and a common electrode 403. Figure 6 In the example shown, the piezoelectric element 402 is individually provided for each piezoelectric element 400. Alternatively, the piezoelectric element 402 can be provided on multiple piezoelectric elements 400 in a shared manner. In this case, the piezoelectric element 402 is in the form of a strip extending continuously along the Y-axis across multiple piezoelectric elements 400.

[0100] The piezoelectric element 402 is composed of a piezoelectric material having a perovskite-type crystal structure represented by the general formula ABO3. Specifically, examples of such piezoelectric materials include lead titanate (PbTiO3), lead zirconate titanate (Pb(Zr,Ti)O3), lead zirconate (PbZrO3), lanthanum lead titanate ((Pb,La),TiO3), lanthanum lead zirconate titanate ((Pb,La)(Zr,Ti)O3), lead zirconate titanate niobate (Pb(Zr,Ti,Nb)O3), and lead magnesium zirconate titanate niobate (Pb(Zr,Ti)(Mg,Nb)O3). Among these, lead zirconate titanate is preferably used as the structural material of the piezoelectric element 402. Additionally, the piezoelectric element 402 may contain small amounts of other elements such as impurities.

[0101] The piezoelectric material 402 is formed, for example, by using a liquid-phase method such as sol-gel or MOD (metal organic decomposition) to form a precursor layer of the piezoelectric material, and then sintering the precursor layer to crystallize it. Here, although the piezoelectric material 402 is composed of a single layer, when it is composed of multiple layers, even if the thickness of the piezoelectric material 402 is increased, it has the advantage of easily improving the properties of the piezoelectric material 402.

[0102] The common electrode 403 is a strip-shaped common electrode extending continuously along the Y-axis, spanning multiple piezoelectric elements 400. A bias potential VBS is applied to the common electrode 403. Here, as will be discussed later... Figure 7As explained, the common electrode 403 is independent in the piezoelectric element 400 corresponding to pressure chamber Ca and the piezoelectric element 400 corresponding to pressure chamber Cb.

[0103] The common electrode 403 is made of metals such as iridium (Ir), titanium (Ti), platinum (Pt), aluminum (Al), nickel (Ni), gold (Au), and copper (Cu), or alloys or conductive oxides containing these metals. The common electrode 403 is formed, for example, by known film deposition techniques such as sputtering, and by known processing techniques such as photolithography and etching. Furthermore, the common electrode 403 may also be composed of multiple layers.

[0104] Figure 7 This is a schematic plan view used to illustrate the piezoelectric element 400 in the first embodiment. Figure 7 In this diagram, n nozzles N are shown as nozzles N_1 to N_n, pressure chambers Ca corresponding to nozzles N_1 to N_n are shown as pressure chambers Ca_1 to Ca_n, and pressure chambers Cb corresponding to nozzles N_1 to N_n are shown as pressure chambers Cb_1 to Cb_n. n is a natural number of 2 or more, and while not specifically limited, it is, for example, in the range of 200 or more and 600 or less. Here, nozzles N_1 to N_n are arranged in the nozzle row direction DN along the V-axis, forming a nozzle row LN. Furthermore, in Figure 7 The diagram illustrates a plurality of individual electrodes 401, a plurality of common electrodes 403, and a plurality of piezoelectric elements 402 disposed on an actuator substrate 420.

[0105] like Figure 7 As shown, the head chip 41a has independent electrodes 401_A1~401_An, independent electrodes 401_B1~401_Bn, piezoelectric bodies 402_A1~402_An, piezoelectric bodies 402_B1~402_Bn, a first common electrode 403_A, and a second common electrode 403_B.

[0106] Independent electrodes 401_A1 to 401_An are independent electrodes 401 corresponding to pressure chambers Ca_1 to Ca_n, respectively. Similarly, independent electrodes 401_B1 to 401_Bn are independent electrodes 401 corresponding to pressure chambers Cb_1 to Cb_n, respectively.

[0107] In this embodiment, the independent electrodes 401_A1 to 401_An and the independent electrodes 401_B1 to 401_Bn are independent on the actuator substrate 420. Here, the independent electrodes 401_A1 to 401_An each have a terminal portion 401a for connection to the wiring substrate 430. The independent electrodes 401_B1 to 401_Bn each have a terminal portion 401b for connection to the wiring substrate 430. The terminal portions 401a and 401b are arranged in the nozzle row direction DN. Figure 7 In the example shown, nozzles N_1 to N_n are respectively positioned between the corresponding terminal portions 401a and 401b when viewed in a planar view.

[0108] Piezoelectric elements 402_A1 to 402_An are piezoelectric elements 402 corresponding to pressure chambers Ca_1 to Ca_n, respectively. Therefore, corresponding independent electrodes 401_A1 to 401_An are connected to piezoelectric elements 402_A1 to 402_An. Similarly, piezoelectric elements 402_B1 to 402_Bn are piezoelectric elements 402 corresponding to pressure chambers Cb_1 to Cb_n, respectively. Therefore, corresponding independent electrodes 401_B1 to 401_Bn are connected to piezoelectric elements 402_B1 to 402_Bn.

[0109] The first common electrode 403_A is a common electrode 403 corresponding to pressure chambers Ca_1 to Ca_n. Therefore, the first common electrode 403_A is connected to piezoelectric bodies 402_A1 to 402_An in a common manner. Here, piezoelectric bodies 402_A1 to 402_An are located between the individual electrodes 401_A1 to 401_An and the first common electrode 403_A. Similarly, the second common electrode 403_B is a common electrode 403 corresponding to pressure chambers Cb_1 to Cb_n. Therefore, the second common electrode 403_B is connected to piezoelectric bodies 402_B1 to 402_Bn in a common manner. Here, piezoelectric bodies 402_B1 to 402_Bn are located between the individual electrodes 401_B1 to 401_Bn and the second common electrode 403_B.

[0110] The first common electrode 403_A and the second common electrode 403_B are independent on the actuator substrate 420. That is, the first common electrode 403_A and the second common electrode 403_B are arranged on the actuator substrate 420 in a spaced-apart manner.

[0111] Here, the first common electrode 403_A has two terminal portions 403a_A for connection with the wiring board 430. The two terminal portions 403a_A are disposed at or near both ends of the first common electrode 403_A in the nozzle row direction DN, and are arranged along the nozzle row direction DN on the same straight line as the aforementioned plurality of terminal portions 401a and plurality of terminal portions 401b.

[0112] Similarly, the second common electrode 403_B has two terminal portions 403a_B for connection to the wiring board 430. These two terminal portions 403a_B are disposed at or near both ends of the second common electrode 403_B in the nozzle row direction DN, and are arranged along the nozzle row direction DN on the same straight line as the aforementioned plurality of terminal portions 401a and 401b. Figure 7 In the example shown, the aforementioned two terminal portions 403a_A are arranged between the two terminal portions 403a_B.

[0113] Piezoelectric elements 400_A1 to 400_An are constructed using the independent electrodes 401_A1 to 401_An, piezoelectric bodies 402_A1 to 402_An, and a first common electrode 403_A. Piezoelectric elements 400_A1 to 400_An are piezoelectric elements 400 corresponding to pressure chambers Ca_1 to Ca_n. Similarly, piezoelectric elements 400_B1 to 400_Bn are constructed using the independent electrodes 401_B1 to 401_Bn, piezoelectric bodies 402_B1 to 402_Bn, and a second common electrode 403_B. Piezoelectric elements 400_B1 to 400_Bn are piezoelectric elements 400 corresponding to pressure chambers Cb_1 to Cb_n.

[0114] Here, among two nozzles N arbitrarily selected from nozzles N_1 to N_n, one is designated as the "first nozzle" and the other as the "second nozzle". Among the pressure chambers Ca and Cb connected to the first nozzle, one is designated as the "first pressure chamber" and the other as the "second pressure chamber". Among the pressure chambers Ca and Cb connected to the second nozzle, one is designated as the "third pressure chamber" and the other as the "fourth pressure chamber". However, for ease of explanation, below, nozzle N_1 is designated as the "first nozzle", nozzle N_2 as the "second nozzle", pressure chamber Ca_1 as the "first pressure chamber", pressure chamber Cb_1 as the "second pressure chamber", pressure chamber Ca_2 as the "third pressure chamber", and pressure chamber Cb_2 as the "fourth pressure chamber".

[0115] 1-6. Wiring board

[0116] Figure 8 This is a schematic diagram used to illustrate the wiring board 430 in the first embodiment. Figure 8As shown, the wiring board 430 has a first common wiring 431_A1, a second common wiring 431_B1, a third common wiring 431_A2, a fourth common wiring 431_B2, two signal lines 432_A, two signal lines 432_B, wirings 433a, 433b, 433c, 434a, 434b, 434c, 434d and independent wirings 435_1 to 435_n.

[0117] Here, the wiring board 430 has a first end E1 and a second end E2 facing in the opposite direction to the first end E1. The first end E1 is the end connected to the relay board 440. The second end E2 is the end connected to the actuator board 420. Figure 5 As shown, in this embodiment, the wiring board 430 is bent along a plane perpendicular to the direction along the Z-axis, with the first end E1 and the second end E2 respectively. Figure 8 In the example shown, the length of the first terminal E1 is shorter than the length of the second terminal E2. Furthermore, as mentioned earlier, a drive circuit 410 is mounted on the wiring board 430.

[0118] The first common wiring 431_A1, the second common wiring 431_B1, the third common wiring 431_A2, and the fourth common wiring 431_B2 are wirings used to transmit the bias potential VBS. The first common wiring 431_A1, the second common wiring 431_B1, the third common wiring 431_A2, and the fourth common wiring 431_B2 are respectively set from the first terminal E1 to the second terminal E2 without passing through the drive circuit 410.

[0119] Here, when viewed in the thickness direction of the wiring board 430, i.e., along the W-axis, a drive circuit 410 is arranged between the first common wiring 431_A1 and the second common wiring 431_B1 and the third common wiring 431_A2 and the fourth common wiring 431_B2. Figure 8 In the example shown, the first common wiring 431_A1 and the second common wiring 431_B1 are configured on the wiring board 430. Figure 8 On the left side of the wiring board 430, the third common wiring 431_A2 and the fourth common wiring 431_B2 are disposed on the wiring board 430. Figure 8 On the right side of the portion. In addition, the first common wiring 431_A1 and the third common wiring 431_A2 are configured between the second common wiring 431_B1 and the fourth common wiring 431_B2.

[0120] The first common wiring 431_A1 and the third common wiring 431_A2 are respectively connected to the two terminal portions 403a_A of the aforementioned actuator substrate 420 via the second terminal E2. Specifically, the first common wiring 431_A1 is connected to one of the two terminal portions 403a_A, and the third common wiring 431_A2 is connected to the other. Therefore, a bias potential VBS as a constant potential is supplied to the first common electrode 403_A via the first common wiring 431_A1 and the third common wiring 431_A2. As described above, the first common wiring 431_A1 and the third common wiring 431_A2 electrically connect the outside of the wiring substrate 430 to the first common electrode 403_A without passing through the drive circuit 410.

[0121] On the other hand, the second common wiring 431_B1 and the fourth common wiring 431_B2 are respectively connected to the two terminal portions 403a_B of the aforementioned actuator substrate 420 via the second terminal E2. Specifically, the second common wiring 431_B1 is connected to one of the two terminal portions 403a_B, and the fourth common wiring 431_B2 is connected to the other. Therefore, a bias potential VBS, which is a constant potential with the same potential as the first common wiring 431_A1, is supplied to the second common electrode 403_B via the second common wiring 431_B1 and the fourth common wiring 431_B2. As described above, the second common wiring 431_B1 and the fourth common wiring 431_B2 are independent of the first common wiring 431_A1 and the third common wiring 431_A2, and are electrically connected to the outside of the wiring substrate 430 and the second common electrode 403_B without passing through the drive circuit 410.

[0122] Two signal lines 432_A are used to transmit the drive signal COM_A. Similarly, two signal lines 432_B are used to transmit the drive signal COM_B. Signal lines 432_A and 432_B extend from the first terminal E1 toward the drive circuit 410 and are connected to it. Furthermore, signal lines 432_A and 432_B are connected to independent wirings 435_1 to 435_n via the drive circuit 410. Thus, signal lines 432_A and 432_B are electrically connected to the outside of the wiring board 430 and the independent wirings 435_1 to 435_n via the drive circuit 410.

[0123] Here, two signal lines 432_B and two signal lines 432_A are configured between the first common wiring 431_A1 and the third common wiring 431_A2. Figure 8In the example shown, two signal lines 432_B are configured between two signal lines 432_A. Furthermore, one of the two signal lines 432_A and one of the two signal lines 432_B are respectively configured on the wiring board 430. Figure 8 On the left side of the circuit, one of the two signal lines 432_A and the other of the two signal lines 432_B are respectively configured on the wiring board 430. Figure 8 On the right side of the middle.

[0124] Wiring 433a is used to transmit the power supply potential VDD. Wiring 433b is used to transmit the power supply potential VHV. Wiring 433c is used to transmit the ground potential GND. Wiring 434a is used to transmit the clock signal SCK. Wiring 434b is used to transmit the printed data signal SI. Wiring 434c is used to transmit the latch signal LAT. Wiring 434d is used to transmit the conversion signal CH. These wirings extend from the first terminal E1 toward the drive circuit 410 and are connected to the drive circuit 410.

[0125] exist Figure 8 In the example shown, wiring 433a, wiring 433b, wiring 433c, wiring 434a, wiring 434b, wiring 434c, and wiring 434d are arranged in that order. Furthermore, the order in which these wirings are configured is not limited to... Figure 8 The example shown is not arbitrary.

[0126] Independent wirings 435_1 to 435_n are used to transmit the drive signal VOUT. Independent wirings 435_1 to 435_n extend from the second terminal E2 toward the drive circuit 410 and are connected to the drive circuit 410.

[0127] Here, individual wirings 435_1 to 435_n correspond to the aforementioned nozzles N_1 to N_n, respectively, and are arranged in the order of individual wirings 435_1 to 435_n. Thus, individual wirings 435_1 to 435_n correspond to individual electrodes 401_A1 to 401_An, respectively. Furthermore, individual wirings 435_1 to 435_n correspond to individual electrodes 401_B1 to 401_Bn, respectively. Moreover, individual wirings 435_1 to 435_n are connected to their corresponding individual electrodes 401 on the aforementioned actuator substrate 420 via the second terminal E2.

[0128] In this embodiment, the independent wirings 435_1 to 435_n each branch midway and extend toward the second end E2. Therefore, each of the independent wirings 435_1 to 435_n has two portions that are provided on the second end E2 via the branch. Furthermore, these two portions are connected to corresponding terminal portions 401a and 401b. For example, independent wiring 435_1 branches in the wiring board 430 and is electrically connected to independent electrodes 401_A1 and 401_B1 respectively. Thus, a common drive signal VOUT is supplied to the two independent electrodes 401 corresponding to the common nozzle N.

[0129] Here, use Figure 9 The switching element 410sw of the drive circuit 410 will be described. Figure 9 This is a schematic diagram illustrating the drive circuit 410. Multiple switching elements 410sw include switching elements 410swa_1 to 410swa_n and switching elements 410swb_1 to 410swb_n. Switching elements 410swa_1 to 410swa_n are switching elements 410sw corresponding to each of the independent electrodes 401_A1 to 401_An and each of the independent electrodes 401_B1 to 401_Bn. Switching elements 410swa_1 to 410swa_n select whether to supply a drive signal COM_A to each piezoelectric element. Switching elements 410swb_1 to 410swb_n are switching elements 410sw corresponding to each of the independent electrodes 401_A1 to 401_An and each of the independent electrodes 401_B1 to 401_Bn. Switching elements 410swb_1 to 410swb_n select whether to supply drive signal COM_B to each piezoelectric element 400.

[0130] To give a specific example, switching element 410swa_1 selects whether to supply drive signal COM_A to independent electrodes 401_A1 and 401_B1, switching element 410swa_2 selects whether to supply drive signal COM_A to independent electrodes 401_A2 and 401_B2, switching element 410swb_1 selects whether to supply drive signal COM_B to independent electrodes 401_A1 and 401_B1, and switching element 410swb_2 selects whether to supply drive signal COM_B to independent electrodes 401_A2 and 401_B2.

[0131] In other words, multiple switching elements 410sw are arranged in a manner corresponding to each of the multiple nozzles N. Specifically, on two independent electrodes 401 corresponding to the same nozzle N, a shared switching element 410sw is used to select whether to supply a drive signal COM_A or a drive signal COM_B to the two independent electrodes 401. By configuring it in this way, compared to the case where each independent switching element 410sw is provided corresponding to each of the two independent electrodes 401, the number of switching elements 410sw can be reduced, and miniaturization and heat generation of the drive circuit 410 can be suppressed.

[0132] Here, drive signal COM_A or drive signal COM_B is an example of a "drive signal".

[0133] Furthermore, among the multiple switching elements 410sw, any one of the switching element 410swa_1 that selects whether to supply drive signal COM_A to independent electrode 401_A1 and independent electrode 401_B1, or the switching element 410swb_1 that selects whether to supply drive signal COM_B, is an example of a "first switching element". The independent electrode 401_A1 is an example of a "first independent electrode" corresponding to nozzle N_1, which is an example of a "first nozzle", and the independent electrode 401_B1 is an example of a "second independent electrode".

[0134] Similarly, among the multiple switching elements 410sw, any one of the switching elements 410sw2 that selects whether to supply drive signal COM_A to independent electrodes 401_A2 and 401_B2, or the switching element 410swb_2 that selects whether to supply drive signal COM_B, is an example of a "second switching element". The independent electrode 401_A2 is an example of a "third independent electrode" corresponding to nozzle N_2, which is an example of a "second nozzle", and the independent electrode 401_B2 is an example of a "fourth independent electrode".

[0135] 1-7. Relay substrate

[0136] Figure 10 This is a schematic diagram used to illustrate the relay substrate 440 in the first embodiment. Figure 10 As shown, the relay substrate 440 has second relay wirings 441_1, 441_2, two first relay wirings 442_A, two first relay wirings 442_B, and wirings 443a, 443b, 443c, 444a, 444b, 444c, and 444d. Figure 10The diagram illustrates a connector 445, any one of a plurality of openings 447, a first end E1 of a wiring board 430 inserted into the opening 447, second trunk wirings 441_1 and 441_2 corresponding to the wiring board 430, two first trunk wirings 442_A, two first trunk wirings 442_B, and wirings 443a, 443b, 443c, 444a, 444b, 444c, and 444d. Additionally, in Figure 10 In order to simplify the accompanying drawings, the relative positional relationships of connector 445 or opening 447, connecting part 446, second trunk wiring 441_1, 441_2, two first trunk wiring 442_A, two first trunk wiring 442_B and wiring 443a, 443b, 443c, 444a, 444b, 444c, 444d are different from the actual positional relationships.

[0137] Here, the relay substrate 440 has a connector 445. The connector 445 is a component for connecting to the aforementioned wiring component 43. Although the relay substrate 440 has the aforementioned recovery circuit 41b, Figure 10 The diagram is omitted. Additionally, the recovery circuit 41b can also be configured outside the connector 445. Although not shown, in this embodiment, the connector 445 is connected to the second trunk lines 441_1, 441_2, two first trunk lines 442_A, two first trunk lines 442_B, and lines 443a, 443b, 443c, 444a, 444b, 444c, and 444d, respectively, corresponding to the head chips 41a_1 to 41a_6.

[0138] The relay substrate 440 has a connection portion 446, which is a portion that is connected to the surface of the first end E1 of the wiring substrate 430 facing the Z2 direction.

[0139] Second trunk wirings 441_1 and 441_2 are wirings used to transmit the bias potential VBS. Second trunk wirings 441_1 and 441_2 are respectively provided from connector 445 to connection part 446.

[0140] Here, the second trunk line 441_1 is connected to both the first common line 431_A1 and the second common line 431_B1 of the aforementioned wiring board 430 via the connection portion 446. On the other hand, the second trunk line 441_2 is connected to both the third common line 431_A2 and the fourth common line 431_B2 of the aforementioned wiring board 430 via the connection portion 446.

[0141] Two first trunk lines 442_A are signal lines used to transmit drive signal COM_A. Conversely, two first trunk lines 442_B are signal lines used to transmit drive signal COM_B. First trunk lines 442_A and 442_B are respectively provided to cross from connector 445 to connection section 446.

[0142] Here, the two first trunk cables 442_A are connected to the two signal lines 432_A of the aforementioned wiring board 430 via the connecting portion 446. On the other hand, the two first trunk cables 442_B are connected to the two signal lines 432_B of the aforementioned wiring board 430 via the connecting portion 446.

[0143] Wiring 443a is used to transmit the power supply potential VDD. Wiring 443b is used to transmit the power supply potential VHV. Wiring 443c is used to transmit the ground potential GND. Wiring 444a is used to transmit the clock signal SCK. Wiring 444b is used to transmit the printed data signal SI. Wiring 444c is used to transmit the latch signal LAT. Wiring 444d is used to transmit the conversion signal CH. These wirings are respectively provided from connector 445 to connection part 446.

[0144] exist Figure 10 In the example shown, wiring 443a, wiring 443b, wiring 443c, wiring 444a, wiring 444b, wiring 444c, and wiring 444d are arranged in that order. Furthermore, the order in which these wirings are configured is not limited to... Figure 10 The example shown is in any order.

[0145] 1-8. Head chip detection

[0146] Figure 11 This diagram illustrates the performance testing of the head chip 41a. The performance testing of the head chip 41a is performed using a measuring tool 200 and switches 300_A and 300_B without connecting the relay substrate 440 to the head chip 41a.

[0147] The measuring instrument 200 is an impedance analyzer having a positive terminal and a negative terminal and measuring the impedance between them. The detection signal is, for example, a sine wave signal. However, the measuring instrument 200 is not limited to an impedance analyzer; it can also be, for example, a current meter or a capacitance meter.

[0148] The positive terminal of the measuring tool 200 is electrically connected to the input side of the drive circuit 410, specifically to at least one of signal lines 432_A and 432_B. On the other hand, the negative terminal of the measuring tool 200 is connected to the first common wiring 431_A1 and the third common wiring 431_A2 via switch 300_A, thereby electrically connecting to the first common electrode 403_A. Furthermore, the negative terminal of the measuring tool 200 is connected to the second common wiring 431_B1 and the fourth common wiring 431_B2 via switch 300_B, thereby electrically connecting to the second common electrode 403_B. The measuring tool 200 outputs a detection signal from the positive terminal as a drive signal COM. Furthermore, when performing performance testing on the head chip 41a, the drive circuit 410 is controlled by connecting wirings 433a, 433b, 433c, 434a, 434b, 434c, and 434d to a control device (not shown).

[0149] Switch 300_A switches between a state in which the first common electrode 403_A is electrically connected to the negative terminal of the measuring tool 200 and a state in which it is electrically connected to a constant potential VMB. Switch 300_B switches between a state in which the second common electrode 403_B is electrically connected to the negative terminal of the measuring tool 200 and a state in which it is electrically connected to a constant potential VMB. Although the constant potential VMB is not specifically limited, it is, for example, a constant potential in the range of 0V to 35V.

[0150] The detection of piezoelectric elements 400_A1 to 400_An is performed when switch 300_A electrically connects the first common electrode 403_A to the negative terminal of the measuring tool 200 and switch 300_B electrically connects the second common electrode 403_B to the constant potential VMB. Here, when detecting a desired piezoelectric element 400 among piezoelectric elements 400_A1 to 400_An, the measuring tool 200 controls the drive of the drive circuit 410 in such a way that the drive signal VOUT, which serves as the detection signal, is input only to that desired piezoelectric element 400. Specifically, for example, when detecting piezoelectric element 400_A1, the drive circuit 410 supplies the drive signal VOUT only to the independent wiring 435_1 connected to piezoelectric element 400_A1. At this time, since the second common electrode 403_B is electrically connected to the constant potential VMB via switch 300_B, piezoelectric element 400_A1, rather than piezoelectric element 400_B1, is positioned between the positive and negative terminals of the measuring tool 200. Therefore, even though the independent wiring 435_1 is a shared wiring for both piezoelectric elements 400_A1 and 400_B1, the impedance of only piezoelectric element 400_A1 can be measured.

[0151] This is because the first common electrode 403_A connected to piezoelectric elements 400_A1 to 400_An and the second common electrode 403_B connected to piezoelectric elements 400_B1 to 400_Bn are independent, and the first common wiring 431_A1 and the third common wiring 431_A2 connected to the first common electrode 403_A and the second common wiring 431_B1 and the fourth common wiring 431_B2 connected to the second common electrode 403_B are independent, so that the switch 300_A connected to the first common electrode 403_A and the switch 300_B connected to the second common electrode 403_B can be set separately.

[0152] On the other hand, the detection of piezoelectric elements 400_B1 to 400_Bn is performed when switch 300_A electrically connects the first common electrode 403_A to the constant potential VMB and switch 300_B electrically connects the second common electrode 403_B to the negative terminal of the measuring tool 200. Here, when detecting a desired piezoelectric element 400 among piezoelectric elements 400_B1 to 400_Bn, the measuring tool 200 controls the drive of the drive circuit 410 to input the drive signal VOUT for detection only to that desired piezoelectric element 400. Specifically, for example, when detecting piezoelectric element 400_B1, the drive circuit 410 supplies the drive signal VOUT only to the independent wiring 435_1 connected to piezoelectric element 400_B1. At this time, since the first common electrode 403_A is electrically connected to the constant potential VMB via switch 300_A, piezoelectric element 400_B1, rather than piezoelectric element 400_A1, is positioned between the positive and negative terminals of the measuring tool 200. Therefore, even though the independent wiring 435_1 is a shared wiring for both piezoelectric elements 400_A1 and 400_B1, the impedance of only piezoelectric element 400_B1 can be measured.

[0153] As described above, the head chip 41a includes a nozzle N_1 as an example of a "first nozzle", a nozzle N_2 as an example of a "second nozzle", a pressure chamber Ca_1 as an example of a "first pressure chamber", a pressure chamber Cb_1 as an example of a "second pressure chamber", a pressure chamber Ca_2 as an example of a "third pressure chamber", a pressure chamber Cb_2 as an example of a "fourth pressure chamber", a piezoelectric element 402_A1 as an example of a "first piezoelectric element", and a piezoelectric element as an example of a "second piezoelectric element". 402_B1, a piezoelectric body as an example of a "third piezoelectric body"; 402_A2, a piezoelectric body as an example of a "fourth piezoelectric body"; 402_B2, an independent electrode as an example of a "first independent electrode"; 401_A1, an independent electrode as an example of a "second independent electrode"; 401_B1, an independent electrode as an example of a "third independent electrode"; 401_A2, an independent electrode as an example of a "fourth independent electrode"; 401_B2, a first common electrode; 403_A, a second common electrode; 403_B.

[0154] Nozzles N_1 and N_2 respectively spray ink, exemplified as a "liquid". Pressure chambers Ca_1 and Cb_1 are connected to nozzle N_1. Pressure chambers Ca_2 and Cb_2 are connected to nozzle N_2. Piezoelectric element 402_A1 generates pressure in pressure chamber Ca_1. Piezoelectric element 402_B1 generates pressure in pressure chamber Cb_1. Piezoelectric element 402_A2 generates pressure in pressure chamber Ca_2. Piezoelectric element 402_B2 generates pressure in pressure chamber Cb_2. Independent electrode 401_A1 is connected to piezoelectric element 402_A1. Independent electrode 401_B1 is connected to piezoelectric element 402_B1. Independent electrode 401_A2 is connected to piezoelectric element 402_A2. Independent electrode 401_B2 is connected to piezoelectric element 402_B2. The first common electrode 403_A is connected to piezoelectric bodies 402_A1 and 402_A2 in a shared manner. The second common electrode 403_B is independent of the first common electrode 403_A and is connected to piezoelectric bodies 402_B1 and 402_B2 in a shared manner.

[0155] In the head chip 41a described above, since the first common electrode 403_A and the second common electrode 403_B are independent of each other, even if a structure is adopted to supply a common drive signal VOUT to the independent electrode 401 corresponding to the common nozzle N, signals can be supplied separately between the independent electrode 401_A1 or the independent electrode 401_A2 and the first common electrode 403_A, and between the independent electrode 401_B1 or the independent electrode 401_B2 and the second common electrode 403_B. Therefore, the head chip 41a can be miniaturized, and the performance of the piezoelectric element 400 can be detected separately for each pressure chamber C.

[0156] Furthermore, as described above, the head chip 41a includes a first common liquid chamber R1 connected to pressure chambers Ca_1 and Ca_2, and a second common liquid chamber R2 connected to pressure chambers Cb_1 and Cb_2. Therefore, ink can be supplied to each pressure chamber Ca from the first common liquid chamber R1 or the second common liquid chamber R2, or ink can be recovered from each pressure chamber Cb to the first common liquid chamber R1 or the second common liquid chamber R2.

[0157] Here, as described above, the first common liquid chamber R1 is a flow channel for supplying ink to pressure chambers Ca_1 and Ca_2. The second common liquid chamber R2 is a flow channel for recovering ink from pressure chambers Cb_1 and Cb_2. Therefore, an ink circulation structure can be realized in which ink is supplied from the first common liquid chamber R1 to each pressure chamber Ca and ink from each pressure chamber Cb is recovered from the second common liquid chamber R2.

[0158] Furthermore, as mentioned above, the head chip 41a includes a pressure chamber substrate 412 and a vibrating plate 415. The pressure chamber substrate 412 has pressure chambers Ca_1, Cb_1, Ca_2, and Cb_2, and the vibrating plate 415 is stacked on the pressure chamber substrate 412. Based on this, a piezoelectric element 402_A1 is located between an independent electrode 401_A1 and a first common electrode 403_A. A piezoelectric element 402_B1 is located between an independent electrode 401_B1 and a second common electrode 403_B. A piezoelectric element 402_A2 is located between an independent electrode 401_A2 and the first common electrode 403_A. A piezoelectric element 402_B2 is located between an independent electrode 401_B2 and the second common electrode 403_B. With this electrode configuration, performance testing of the head chip 41a can be performed for each pressure chamber C.

[0159] Furthermore, as described above, the head chip 41a includes a nozzle array LN composed of a plurality of nozzles N arranged in the nozzle array direction DN. Moreover, nozzles N_1 and N_2 are arranged in the nozzle array direction DN and constitute part of the nozzle array LN. Therefore, when viewed along the ejection direction from nozzle N_1 or nozzle N_2, nozzle N_1 can be positioned between pressure chamber Ca_1 and pressure chamber Cb_1, and nozzle N_2 can be positioned between pressure chamber Ca_2 and pressure chamber Cb_2.

[0160] Furthermore, as mentioned above, pressure chambers Ca_1 and Cb_1 are arranged in a direction intersecting the nozzle array direction DN. Pressure chambers Ca_2 and Cb_2 are arranged in a direction intersecting the nozzle array direction DN. Pressure chambers Ca_1 and Ca_2 are arranged in the nozzle array direction DN. Pressure chambers Cb_1 and Cb_2 are arranged in the nozzle array direction DN. Based on this, nozzle N_1 is positioned between pressure chambers Ca_1 and Cb_1 when viewed along the ejection direction of ink ejected from nozzle N_1 or nozzle N_2. Nozzle N_2 is positioned between pressure chambers Ca_2 and Cb_2 when viewed along the ejection direction of ink ejected from nozzle N_1 or nozzle N_2. Therefore, it is possible to apply voltages separately between the independent electrode 401_A1 or the independent electrode 401_A2 and the first common electrode 403_A, or between the independent electrode 401_B1 or the independent electrode 401_B2 and the second common electrode 403_B.

[0161] Furthermore, as described above, the head chip 41a includes a wiring board 430 on which a driving circuit 410 is mounted, the driving circuit 410 driving piezoelectric elements 402_A1, 402_B1, 402_A2, and 402_B2. The wiring board 430 also includes an independent wiring 435_1 (an example of a "first independent wiring"), an independent wiring 435_2 (an example of a "second independent wiring"), signal lines 432_A and 432_B, a first common wiring 431_A1, and a second common wiring 431_B1. Signal lines 432_A and 432_B are electrically connected to the outside of the wiring board 430 and the independent wiring 435_1 and 435_2 via the driving circuit 410. Independent wiring 435_1 electrically connects the drive circuit 410 to independent electrodes 401_A1 and 401_B1. Therefore, a common drive signal can be supplied to independent electrodes 401_A1 and 401_B1 using independent wiring 435_1. Independent wiring 435_2 electrically connects the drive circuit 410 to independent electrodes 401_A2 and 401_B2. Therefore, a common drive signal can be supplied to independent electrodes 401_A2 and 401_B2 using independent wiring 435_2.

[0162] The first common wiring 431_A1 electrically connects the outside of the wiring substrate 430 to the first common electrode 403_A without passing through the drive circuit 410. The second common wiring 431_B1, independent of the first common wiring 431_A1, electrically connects the outside of the wiring substrate 430 to the second common electrode 403_B without passing through the drive circuit 410. Therefore, a constant potential can be supplied from the outside of the wiring substrate 430 to the first common electrode 403_A using the first common wiring 431_A1, and a constant potential can be supplied from the outside of the wiring substrate 430 to the second common electrode 403_B using the second common wiring 431_B1.

[0163] Furthermore, as described above, the head chip 41a includes an actuator substrate 420. The actuator substrate 420 has pressure chambers Ca_1, Cb_1, Ca_2, and Cb_2, and is equipped with independent electrodes 401_A1, 401_B1, 401_A2, and 401_B2. Independent wiring 435_1 branches in the wiring substrate 430 and is electrically connected to independent electrodes 401_A1 and 401_B1 respectively. Independent wiring 435_2 branches in the wiring substrate 430 and is electrically connected to independent electrodes 401_A2 and 401_B2 respectively. Therefore, a wiring substrate 430 can be implemented in an actuator substrate 420 with a structure that allows for independent electrodes for each pressure chamber C. This actuator substrate 420 differs from the wiring substrate 430 in that the independent wiring is not branched and is independent. Furthermore, when each independent wiring is connected to a wiring substrate with a structure corresponding to each independent electrode, it is possible to realize a head chip that drives two piezoelectric elements 400 corresponding to the same nozzle N respectively.

[0164] Furthermore, as mentioned above, the first common wiring 431_A1 supplies a constant potential to the first common electrode 403_A. The second common wiring 431_B1 supplies a constant potential to the second common electrode 403_B, which is the same as that of the first common wiring 431_A1. Therefore, each piezoelectric element 402 can be driven in the same way as when the first common electrode 403_A and the second common electrode 403_B are shared.

[0165] Furthermore, as described above, each of signal lines 432_A and 432_B is supplied with a drive signal COM_A and a drive signal COM_B for driving piezoelectric elements 402_A1, 402_B1, 402_A2, and 402_B2, respectively. The drive circuit 410 includes multiple switching elements 410sw that select whether to supply drive signal COM_A to independent electrodes 401_A1 and 401_B1, and multiple switching elements 410sw that select whether to supply drive signal COM_A to independent electrodes 401_A2 and 401_B2. Furthermore, the drive circuit 410 includes multiple switching elements 410sw that select whether to supply drive signal COM_B to independent electrodes 401_A1 and 401_B1, and multiple switching elements 410sw that select whether to supply drive signal COM_B to independent electrodes 401_A2 and 401_B2. Therefore, compared to a structure that provides separate switching elements 410sw for multiple independent electrodes 401 corresponding to the same nozzle N, the number of switching elements 410sw can be reduced. As a result, the drive circuit 410 can be miniaturized.

[0166] Furthermore, as described above, the wiring substrate 430 has a third common wiring 431_A2 and a fourth common wiring 431_B2. The third common wiring 431_A2 is independent of the first common wiring 431_A1 and the second common wiring 431_B1, and electrically connects the outside of the wiring substrate 430 to the first common electrode 403_A without passing through the drive circuit 410. The fourth common wiring 431_B2 is independent of the first common wiring 431_A1, the second common wiring 431_B1, and the third common wiring 431_A2, and electrically connects the outside of the wiring substrate 430 to the second common electrode 403_B without passing through the drive circuit 410. Based on this, the drive circuit 410 is disposed between the first common wiring 431_A1 and the second common wiring 431_B1 and the third common wiring 431_A2 and the fourth common wiring 431_B2 when viewed along the thickness direction of the wiring substrate 430. Therefore, a constant potential for the common electrode 403 can be supplied to the vicinity of both ends in the longitudinal direction of the actuator substrate 420. As a result, the potential drop of the common electrode 403 caused by different positions in the nozzle row direction DN can be reduced.

[0167] Furthermore, as described above, the liquid injection head 41 has at least one head chip 41a and a relay substrate 440. The relay substrate 440 has a first relay wiring 442_A, 442_B electrically connected to signal lines 432_A, 432_B, and a second relay wiring 441_1 electrically connected to both the first shared wiring 431_A1 and the second shared wiring 431_B1 in a shared manner. Therefore, by sharing the first shared wiring 431_A1 and the second shared wiring 431_B1 through the second relay wiring 441_1, the wiring arrangement can be simplified. In addition, the thickness of the second relay wiring 441_1 can be increased, which results in the prevention of potential drop for the first shared wiring 431_A1 and the second shared wiring 431_B1.

[0168] In this embodiment, as described above, a wiring substrate 430 is connected to a plurality of head chips 41a on the relay substrate 440. Thus, when a liquid jet head 41 includes a plurality of head chips 41a, the yield rate during manufacturing of the liquid jet head 41 will be poor if performance testing cannot be performed on each head chip 41a. Therefore, in this case, being able to perform performance testing on each head chip 41a is particularly useful for improving the yield rate.

[0169] 2. Second Implementation Method

[0170] The second embodiment of this disclosure will now be described. The description will focus on the differences between this embodiment and the first embodiment.

[0171] Figure 12 This is a schematic plan view for explaining the piezoelectric element 400 in the second embodiment. In this embodiment, the individual electrodes 401_A1 to 401_An and the individual electrodes 401_B1 to 401_Bn are electrically connected to each other on the actuator substrate 420 for each nozzle N. Here, the individual electrodes 401_A1 to 401_An and the individual electrodes 401_B1 to 401_Bn have a terminal portion 401c for connection to the wiring substrate 430 for each nozzle N. The terminal portions 401c are arranged in the nozzle row direction DN. Figure 12 In the example shown, nozzles N_1 to N_n overlap with their corresponding terminal portions 401c when viewed in a plane.

[0172] Figure 13This is a schematic diagram for explaining the wiring board 430 in the second embodiment. In this embodiment, the individual wirings 435_1 to 435_n extend toward the second end E2 without branching. Furthermore, the individual wirings 435_1 to 435_n are each connected to their corresponding terminal portions 401c. Thus, a common drive signal VOUT is supplied to the two individual electrodes 401 corresponding to the common nozzle N.

[0173] According to the second embodiment described above, the head chip 41a can also be miniaturized, and detection can be performed individually for each pressure chamber C. In this embodiment, as described above, the independent electrodes 401_A1 and 401_B1 are electrically connected to each other on the actuator substrate 420. Therefore, the number of terminals on the wiring board 430 can be reduced.

[0174] Furthermore, as mentioned above, one end of independent wiring 435_1 is a terminal shared by independent electrodes 401_A1 and 401_B1, and one end of independent wiring 435_2 is a terminal shared by independent electrodes 401_A2 and 401_B2. Therefore, the number of terminals on the wiring board 430 can be reduced.

[0175] 3. Third Implementation Method

[0176] The third embodiment of this disclosure will now be described. The description will focus on the differences between this embodiment and the first embodiment.

[0177] Figure 14 This is a schematic plan view for explaining the piezoelectric element 400 in the third embodiment. This embodiment is identical to the second embodiment described above, except that the four pressure chambers C are connected to one nozzle N. Therefore, with n piezoelectric elements 400 corresponding to pressure chambers Ca and Cb respectively, the number of nozzles N constituting the nozzle array LN is n / 2.

[0178] In this embodiment, ink is ejected from the nozzle N by simultaneously driving the piezoelectric elements 400 corresponding to the four pressure chambers C that are connected to the common nozzle N.

[0179] Here, one of the two nozzles N arbitrarily selected from nozzles N_1 to N_n / 2 is designated as the "first nozzle," and the other as the "second nozzle." Of the two pressure chambers Ca and Cb connected to the first nozzle, any pressure chamber Ca is an example of the "first pressure chamber," and any pressure chamber Cb is an example of the "second pressure chamber." Of the two pressure chambers Ca and Cb connected to the second nozzle, any pressure chamber Ca is an example of the "third pressure chamber," and any pressure chamber Cb is an example of the "fourth pressure chamber." Furthermore, the independent electrode 401 corresponding to the "first pressure chamber" is the "first independent electrode," the independent electrode 401 corresponding to the "second pressure chamber" is the "second independent electrode," the independent electrode 401 corresponding to the "third pressure chamber" is the "third independent electrode," and the independent electrode 401 corresponding to the "fourth pressure chamber" is the "fourth independent electrode."

[0180] According to the third embodiment described above, it is also possible to achieve miniaturization of the head chip 41a, suppression of heat generation, and individual detection for each pressure chamber C.

[0181] 4. Variations

[0182] The methods illustrated above can be modified in a variety of ways. Below, specific modifications applicable to the aforementioned methods are illustrated. Methods arbitrarily selected from the following examples can be appropriately combined within the bounds of non-contradiction.

[0183] 4-1. Variation Example 1

[0184] Although the aforementioned embodiments illustrate structures using two drive signals COM_A and COM_B, the circuit is not limited to this structure. The number of types of drive signals input to the drive circuit 410 can be one or more. Furthermore, the number of pulses contained in the drive signal COM can be one or more.

[0185] 4-2. Variation Example 2

[0186] Although the aforementioned embodiments illustrate a structure in which multiple head chips 41a are mounted on the liquid injection head 41, the invention is not limited to this structure. The number of multiple head chips 41a mounted on the liquid injection head 41 is arbitrary and may be one.

[0187] 4-3. Variation Example 3

[0188] Although the aforementioned configurations illustrate structures with two or four pressure chambers C corresponding to one nozzle N, the configuration is not limited to these configurations, and the number of pressure chambers C corresponding to one nozzle N may, for example, be six or eight or more.

[0189] 4-4. Variation Example 4

[0190] Although the foregoing embodiments illustrate structures in which the ink used in the liquid jet head is circulated by a circulation mechanism, the embodiments are not limited to such structures and may also include structures without such a circulation mechanism.

[0191] 4-5. Variation Example 5

[0192] Although the aforementioned embodiments illustrate a row-type liquid jetting device 100 in which multiple nozzles N are distributed across the entire width of the medium M, the present invention can also be applied to a serial-type liquid jetting device in which a conveyor body equipped with a liquid jetting head 41 moves back and forth in the width direction of the medium M.

[0193] 4-6. Variation Example 6

[0194] The liquid jetting apparatus 100 illustrated in the foregoing embodiments can be used not only in printing equipment but also in various other devices such as fax machines and copiers; the application of the present invention is not particularly limited. However, the application of the liquid jetting apparatus is not limited to printing. For example, a liquid jetting apparatus that jets a solution of color material is used as an apparatus for manufacturing color filters for display devices such as liquid crystal display panels. Furthermore, a liquid jetting apparatus that jets a solution of conductive material is used as an apparatus for manufacturing wiring or electrodes for wiring substrates. Additionally, a liquid jetting apparatus that jets a solution of organic matter related to living organisms is used, for example, as an apparatus for manufacturing biochips.

[0195] 4-7. Variation Example 7

[0196] Although the drive module 42 together with the liquid injection head 41 constitutes the head unit 40 in the various embodiments described above, it is not limited to this structure. For example, the drive module 42 may also be part of the control unit 20.

[0197] Symbol Explanation

[0198] 10…Liquid container; 20…Control unit; 30…Conveying mechanism; 34…Pressure chamber base plate; 40…Head unit; 41…Liquid injection head; 41a…Head chip; 41a_1~41a_m…Head chip; 41b…Recovery circuit; 42…Drive module; 42a…Control circuit; 42b…Power supply circuit; 42c…Drive signal output circuit; 42c_1~42c_m…Drive signal output circuit; 42d…Conversion circuit; 43…Wiring components; 45…Drive circuit; 50…Circulation mechanism; 100…Liquid injection device; 200…Measuring tool; 300_A…Switch; 300_B…Switch; 400…Piezoelectric element; 400_A1~400_An…Piezoelectric element; 400_B1~4 00_Bn… Piezoelectric element; 401… Independent electrode; 401_A1… Independent electrode (first independent electrode); 401_A2… Independent electrode (third independent electrode); 401_B1… Independent electrode (second independent electrode); 401_B2… Independent electrode (fourth independent electrode); 401a… Terminal portion; 401b… Terminal portion; 401c… Terminal portion; 402… Piezoelectric body; 402_A1… Piezoelectric body (first piezoelectric body); 402_A2… Piezoelectric body (third piezoelectric body); 402_B1… Piezoelectric body (second piezoelectric body); 402_B2… Piezoelectric body (fourth piezoelectric body); 403… Common electrode; 403_A… First common electrode; 403_B… Second common electrode; 403a_A… Terminal Sub-section; 403a_B…Terminal section; 410…Drive circuit; 410_1~410_m…Drive circuit; 410sw…Switching element; 411…Flow channel substrate; 412…Pressure chamber substrate; 413…Nozzle substrate; 414…Vibration absorber; 415…Vibrating plate; 415a…First layer; 415b…Second layer; 416…Cover; 417…Outer shell; 420…Actuator substrate; 430…Wiring substrate; 431_A1…First common wiring; 431_A2…Third common wiring; 431_B1…Second common wiring; 431_B2…Fourth common wiring; 432_A…Signal line; 432_B…Signal line; 433a…Wiring; 433b…Wiring; 433c…Wiring; 434a… Wiring; 434b… Wiring; 434c… Wiring; 434d… Wiring; 435_1… Independent Wiring; 435_2… Independent Wiring; 440… Relay Board; 441_1… Second Relay Wiring; 441_2… Second Relay Wiring; 442_A… First Relay Wiring; 442_B… First Relay Wiring; 443a… Wiring; 443b… Wiring; 443c… Wiring; 444a… Wiring; 444b… Wiring; 444c… Wiring; 444d… Wiring; 445… Connector; 446… Connection Part; C… Pressure Chamber; CH… Conversion Signal; COM… Drive Signal; COM_A… Drive Signal; COM_B… Drive Signal; Ca… Pressure Chamber; Ca_1… Pressure Chamber (First Pressure Chamber);Ca_2…Pressure chamber (third pressure chamber); Cb…Pressure chamber; Cb_1…Pressure chamber (second pressure chamber); Cb_2…Pressure chamber (fourth pressure chamber); DATA…Data signal; DN…Nozzle array direction; E1…First end; E2…Second end; GND…Ground potential; GVDD…Power supply potential; H1…Supply port; H2…Discharge port; IP…Image information; LAT…Latch signal; LN…Nozzle array; M…Medium; N…Nozzle; N_1…Nozzle (first nozzle); N_2…Nozzle (second nozzle); Na1…First longitudinal channel; Na2…Second longitudinal channel; Nf…Nozzle channel; Nf1…Cross channel; P…Independent channel; PA1…Pulse; PA 2…pulse; PB1…pulse; PB2…pulse; PlsC…pulse; PlsL…pulse; R1…first common liquid chamber; R1a…space; R1b…space; R2…second common liquid chamber; R2a…space; R2b…space; Ra1…supply channel; Ra2…discharge channel; SCK…clock signal; SI…printing data signal; SI_1~SI_m…printing data signal; Tu…unit period; Tu1…control period; Tu2…control period; VBS…bias potential; VDD…power supply potential; VHV…power supply potential; VMB…constant potential; VOUT…drive signal; ch…conversion signal; dA…drive data; dB…drive data.

Claims

1. A head chip, characterized in that, have: The first nozzle sprays liquid; The second nozzle sprays liquid; A first pressure chamber, which is connected to the first nozzle; The second pressure chamber is connected to the first nozzle; The third pressure chamber is connected to the second nozzle; The fourth pressure chamber is connected to the second nozzle; A first piezoelectric element causes pressure to be generated in the first pressure chamber; The second piezoelectric element causes pressure to be generated in the second pressure chamber; A third piezoelectric element causes pressure to be generated in the third pressure chamber; A fourth piezoelectric element, which generates pressure in the fourth pressure chamber; A first independent electrode is connected to the first piezoelectric element; A second independent electrode is connected to the second piezoelectric element; A third independent electrode is connected to the third piezoelectric element; A fourth independent electrode is connected to the fourth piezoelectric element; A first common electrode is connected to the first piezoelectric body and the third piezoelectric body in a shared manner; The second common electrode is independent of the first common electrode and is connected to the second piezoelectric body and the fourth piezoelectric body in a shared manner. A wiring board, on which a drive circuit is mounted to drive the first piezoelectric element, the second piezoelectric element, the third piezoelectric element, and the fourth piezoelectric element. The wiring substrate has: The first independent wiring connects the drive circuit to the first independent electrode and the second independent electrode. The second independent wiring connects the drive circuit to the third independent electrode and the fourth independent electrode. The signal line is electrically connected to the outside of the wiring board and the first independent wiring and the second independent wiring via the driving circuit. The first common wiring connects the outside of the wiring board to the first common electrode without passing through the driving circuit. The second common wiring is independent of the first common wiring and is electrically connected to the outside of the wiring substrate and the second common electrode without passing through the driving circuit. A drive signal is supplied to the signal line to drive the first piezoelectric element, the second piezoelectric element, the third piezoelectric element, and the fourth piezoelectric element. The driving circuit includes: A first switching element selects whether to supply the drive signal to the first independent electrode and the second independent electrode; The second switching element selects whether to supply the drive signal to the third independent electrode and the fourth independent electrode.

2. The head chip as described in claim 1, characterized in that, have: The first common liquid chamber is connected to the first pressure chamber and the third pressure chamber; The second common liquid chamber is connected to the second pressure chamber and the fourth pressure chamber.

3. The head chip as described in claim 2, characterized in that, The first common liquid chamber is a flow channel for supplying liquid to the first pressure chamber and the third pressure chamber. The second common liquid chamber is a flow channel for recovering liquid from the second pressure chamber and the fourth pressure chamber.

4. The head chip according to any one of claims 1 to 3, characterized in that, have: A pressure chamber substrate having a first pressure chamber, a second pressure chamber, a third pressure chamber, and a fourth pressure chamber; A vibrating plate, which is stacked on the pressure chamber substrate, The first piezoelectric element is located between the first independent electrode and the first common electrode. The second piezoelectric element is located between the second independent electrode and the second common electrode. The third piezoelectric element is located between the third independent electrode and the first common electrode. The fourth piezoelectric element is located between the fourth independent electrode and the second common electrode.

5. The head chip as described in claim 1, characterized in that, It has a nozzle array, which consists of a plurality of nozzles arranged in a nozzle array direction. The first nozzle and the second nozzle are arranged in the direction of the nozzle array and form part of the nozzle array.

6. The head chip as described in claim 5, characterized in that, The first pressure chamber and the second pressure chamber are arranged in a direction intersecting the nozzle array direction. The third pressure chamber and the fourth pressure chamber are arranged in a direction that intersects the direction of the nozzle array. The first pressure chamber and the third pressure chamber are arranged in the direction of the nozzle array. The second pressure chamber and the fourth pressure chamber are arranged in the direction of the nozzle array. The first nozzle is positioned between the first pressure chamber and the second pressure chamber when viewed along the jetting direction of the liquid ejected from either the first nozzle or the second nozzle. The second nozzle is positioned between the third and fourth pressure chambers when viewed along the jetting direction of the liquid ejected from either the first or second nozzle.

7. The head chip as described in claim 1, characterized in that, have: A first nozzle flow channel, which connects the first pressure chamber and the second pressure chamber to the first nozzle, and is a space that connects the first pressure chamber and the second pressure chamber; The second nozzle flow channel connects the third pressure chamber and the fourth pressure chamber to the second nozzle, and is a space that connects the third pressure chamber and the fourth pressure chamber.

8. The head chip as described in claim 1, characterized in that, The device includes an actuator substrate having a first pressure chamber, a second pressure chamber, a third pressure chamber, and a fourth pressure chamber. The first common electrode and the second common electrode are disposed on the actuator substrate.

9. The head chip as described in claim 1, characterized in that, The actuator substrate includes a first pressure chamber, a second pressure chamber, a third pressure chamber, and a fourth pressure chamber, and is equipped with a first independent electrode, a second independent electrode, a third independent electrode, and a fourth independent electrode. The first independent wiring is electrically connected to the first independent electrode and the second independent electrode respectively by branching in the wiring substrate. The second independent wiring is electrically connected to the third independent electrode and the fourth independent electrode respectively by branching in the wiring substrate.

10. The head chip as described in claim 1, characterized in that, The actuator substrate includes a first pressure chamber, a second pressure chamber, a third pressure chamber, and a fourth pressure chamber, and is equipped with a first independent electrode, a second independent electrode, a third independent electrode, and a fourth independent electrode. The first independent electrode and the second independent electrode are electrically connected to each other on the actuator substrate. The third independent electrode and the fourth independent electrode are electrically connected to each other on the actuator substrate.

11. The head chip as described in claim 10, characterized in that, One end of the first independent wiring is a terminal shared by the first independent electrode and the second independent electrode. One end of the second independent wiring is a terminal shared by the third independent electrode and the fourth independent electrode.

12. The head chip according to any one of claims 1, 9 to 11, characterized in that, The first common wiring supplies a constant potential to the first common electrode. The second common wiring supplies a constant potential to the second common electrode, which is at the same potential as the first common wiring.

13. The head chip as described in claim 1, characterized in that, The wiring substrate has: The third common wiring is independent of the first common wiring and the second common wiring, and is electrically connected to the outside of the wiring substrate and the first common electrode without passing through the driving circuit. The fourth common wiring is independent of the first common wiring, the second common wiring, and the third common wiring, and is electrically connected to the outside of the wiring substrate and the second common electrode without passing through the driving circuit. The driving circuit is configured between the first common wiring and the second common wiring and the third common wiring and the fourth common wiring when viewed along the thickness direction of the wiring substrate.

14. A liquid injection head, characterized in that, have: At least one head chip as described in any one of claims 1, 9 to 13; Relay substrate, The relay substrate has: The first trunk wiring is electrically connected to the signal line; The second trunk line is electrically connected to the first common line and the second common line in a shared manner.

15. The liquid injection head as claimed in claim 14, characterized in that, At least one of the head chips is composed of multiple head chips. The relay substrate is connected to the respective wiring substrates of the plurality of head chips.

16. A liquid injection head, characterized in that, have: The head chip according to any one of claims 1 to 13; A relay substrate, which is connected to the head chip.

17. A liquid injection device, characterized in that, have: The liquid injection head according to any one of claims 14 to 16; Wiring components that are connected to the liquid injection head.

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