Liquid dispensing head

Abstract

To provide a liquid dispensing head with high signal transmission accuracy in analog signal wiring. [Solution] The liquid discharge head comprises a piezoelectric substrate having a plurality of piezoelectric elements, a wiring board, and a flexible printed circuit board electrically connecting the piezoelectric substrate and the wiring board, wherein the flexible printed circuit board has a plurality of drive signal wirings for transmitting drive signals to drive the plurality of piezoelectric elements, analog signal wiring for transmitting analog signals, and constant voltage wiring that is maintained at a constant voltage, and the constant voltage wiring is arranged between the drive signal wiring and the analog signal wiring in a first direction intersecting the direction in which the constant voltage wiring is arranged.

Description

Technical Field

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

Background Art

[0002] Conventionally, a liquid ejection device including a liquid ejection head that ejects a liquid such as ink onto a medium such as printing paper has been proposed. As the liquid ejection head, a head that ejects the liquid filled in a pressure chamber from a nozzle by vibrating a diaphragm that constitutes a wall surface of the pressure chamber with a piezoelectric element is known.

[0003] Generally, piezoelectric elements are provided corresponding to each of a plurality of nozzles. By driving each piezoelectric element according to a drive signal, a predetermined amount of liquid is ejected from the corresponding nozzle at a predetermined timing. As a result, dots are formed on the medium. A piezoelectric element is a capacitive load like a capacitor electrically. Therefore, in order to operate the piezoelectric element of each nozzle, it is necessary to supply sufficient current to the piezoelectric element.

[0004] Patent Document 1 discloses a liquid ejection head having a plurality of nozzles arranged in a row of 300 or more per inch and a wiring structure for stably driving each of the plurality of nozzles.

[0005] Patent Document 2 discloses a technique for improving the ejection accuracy of a liquid ejection head by arranging a resistance wiring near a nozzle and correcting a drive signal for ejection using the electrical resistance value of the resistance wiring. The liquid ejection head of the document has a temperature information output circuit as an analysis unit and a control circuit. The temperature information output circuit outputs a temperature corresponding to the electrical resistance value of the resistance wiring as an analog sensor as a temperature information signal that is an analog signal. The control circuit corrects a control signal based on the temperature information signal. Based on the control signal, the signal waveform of the drive signal is corrected.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Patent No. 7483318 [Patent Document 2] Japanese Patent Publication No. 2024-051474 [Overview of the project] [Problems that the invention aims to solve]

[0007] In liquid dispensing heads with high nozzle density, care had to be taken to ensure that noise was not superimposed on the analog signals output from analog sensors located near the nozzles before they could be transmitted to the analysis unit.

[0008] In light of the circumstances described herein, the inventors have discovered a new wiring design method that provides high signal transmission accuracy in analog signal wiring for transmitting analog signals. [Means for solving the problem]

[0009] A liquid discharge head according to a preferred embodiment of the present invention comprises a piezoelectric substrate having a plurality of piezoelectric elements, a wiring board, and a flexible printed circuit board electrically connecting the piezoelectric substrate and the wiring board, wherein the flexible printed circuit board has a plurality of drive signal wirings for transmitting drive signals to drive the plurality of piezoelectric elements, analog signal wiring for transmitting analog signals, and constant voltage wiring that is maintained at a constant voltage, and the constant voltage wiring is arranged between the drive signal wiring and the analog signal wiring in a first direction intersecting the direction in which the constant voltage wiring is arranged. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram illustrating the configuration of a liquid dispensing device according to the first embodiment. [Figure 2] This figure shows the functional configuration of the liquid dispensing device shown in Figure 1. [Figure 3] Figure 2 is a cross-sectional view of the liquid dispensing head. [Figure 4]Figure 3 is an exploded perspective view showing the liquid dispensing module. [Figure 5] Figure 4 is an exploded perspective view of the head chip of the liquid dispensing module. [Figure 6] Figure 5 is a cross-sectional view showing a piezoelectric substrate. [Figure 7] Figure 5 is a cross-sectional view showing a piezoelectric substrate. [Figure 8] Figure 5 is a plan view of the piezoelectric substrate. [Figure 9] This figure shows a flexible printed circuit board as shown in Figure 4. [Figure 10] Figure 9 is a perspective view showing a portion of the flexible printed circuit board. [Figure 11] Figure 9 is a perspective view showing a portion of the flexible printed circuit board. [Figure 12] Figure 9 shows the mounting area and its vicinity in an unbent state of the flexible printed circuit board. [Figure 13] Figure 9 is a diagram illustrating the connection between the various wirings on the flexible printed circuit board shown and the various electrodes provided on the piezoelectric substrate. [Modes for carrying out the invention]

[0011] Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings. Note that the dimensions or scale of each part in the drawings may differ from the actual dimensions as appropriate, and some parts are shown schematically for ease of understanding. Furthermore, the scope of the present invention is not limited to these embodiments unless otherwise stated in the following description. Also, "element β on element γ" is not limited to a configuration in which element γ and element β are in direct contact, but also includes configurations in which element γ and element β are not in direct contact. "Element γ and element β are equal" means that element γ and element β are substantially equal, including manufacturing tolerances, etc.

[0012] 1. First Embodiment 1-1. Overall configuration of the liquid dispensing device 100 FIG. 1 is a schematic diagram illustrating the configuration of a liquid ejection device 100 according to the first embodiment. Hereinafter, for convenience of explanation, the X-axis, Y-axis, and Z-axis that are orthogonal to each other will be appropriately used for explanation. Also, one direction along the X-axis is denoted as the X1 direction, and the direction opposite to the X1 direction is denoted as the X2 direction. Similarly, one direction along the Y-axis is denoted as the Y1 direction, and the direction opposite to the Y1 direction is denoted as the Y2 direction. One direction along the Z-axis is denoted as the Z1 direction, and the direction opposite to the Z1 direction is denoted as the Z2 direction. Looking in the direction along the Z-axis is referred to as "plan view". The Z-axis is typically a vertical axis. The Z2 direction is the upper side, and the Z1 direction is the lower side. However, the Z-axis does not necessarily have to be a vertical axis. Also, the X-axis, Y-axis, and Z-axis are typically orthogonal to each other, but are not limited thereto, and for example, they may intersect at an angle within the range of 80° or more and 100° or less.

[0013] The liquid ejection device 100 in FIG. 1 is an inkjet printing device that ejects a liquid such as ink onto a medium 90. The liquid ejection device 100 is of a serial head type. The medium 90 is typically printing paper, but a printing target of any material such as a resin film or fabric can be used as the medium 90. Also, a liquid container 9 for storing the liquid is installed in the liquid ejection device 100. For example, a cartridge that is detachable from the liquid ejection device 100, a bag-shaped liquid pack formed of a flexible film, or a liquid tank that can be replenished with the liquid is used as the liquid container 9.

[0014] The liquid ejection device 100 includes a control unit 10, a medium conveyance mechanism 15, a movement mechanism 14, and a liquid ejection head 200.

[0015] The control unit 10 includes one or more processing circuits such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array), and one or more storage circuits such as a semiconductor memory, and comprehensively controls each element of the liquid ejection device 100.

[0016] The media transport mechanism 15 transports the media 90 in a direction along the Y-axis under the control of the control unit 10. The media transport mechanism 15 includes a transport motor 151 and a plurality of transport rollers 152. The transport motor 151 operates based on the control of the control unit 10. The plurality of transport rollers 152 rotate in accordance with the operation of the transport motor 151. As the plurality of transport rollers 152 rotate, the media 90 is transported in a direction along the Y-axis, which is the transport direction.

[0017] The moving mechanism 14, under the control of the control unit 10, reciprocates the carriage 20C, on which the liquid discharge head 200 is mounted, along the X-axis. The moving mechanism 14 includes a carriage motor 141 and an endless belt 142. The carriage motor 141 operates based on the control of the control unit 10. The endless belt 142 rotates in accordance with the operation of the carriage motor 141. As a result, the carriage 20C, which is fixed to the endless belt 142, reciprocates along the X-axis, which is the scanning axis. The moving mechanism 14 is also fitted with a linear encoder 16, shown in Figure 2 (described later), for outputting a detection signal based on the position of the carriage 20C.

[0018] The liquid dispensing head 200 dispenses liquid supplied from the liquid container 9 onto the medium 90 from multiple nozzles under the control of the control unit 10. As the medium 90 is transported by the medium transport mechanism 15 and the carriage 20C is reciprocated by the moving mechanism 14, each liquid dispensing head 200 dispenses liquid onto the medium 90, thereby forming an image on the surface of the medium 90.

[0019] The liquid dispensing device 100 is a serial head type in which the liquid dispensing head 200 moves back and forth on the medium 90. However, the liquid dispensing device 100 may also be a line head type in which the liquid dispensing head 200 is fixed.

[0020] Figure 2 shows the functional configuration of the liquid dispensing device 100 shown in Figure 1.

[0021] The control unit 10 includes a control circuit 11, a drive circuit 12, and a reference voltage signal output circuit 13. The control circuit 11 receives image information signals, including image data, from an external device such as a host computer that is communicatively connected to the outside of the liquid dispensing device 100. Based on the image information signals, the control circuit 11 generates various signals for controlling the liquid dispensing device 100 and outputs them to the corresponding configurations.

[0022] In addition to the image information signal, the control circuit 11 receives a detection signal from the linear encoder 16 based on the scanning position of the carriage 20C. Based on this detection signal, the control circuit 11 determines the scanning position of the liquid discharge head 200 mounted on the carriage 20C. The control circuit 11 generates a control signal Ctrl-C to control the movement of the liquid discharge head 200 according to the scanning position of the liquid discharge head 200 and outputs it to the carriage motor 141. The control circuit 11 also generates a control signal Ctrl-T to control the transport of the medium 90 and outputs it to the transport motor 151.

[0023] The control circuit 11 generates and outputs a control signal Ctrl-H for controlling the liquid discharge head 200 based on the aforementioned image information signal and the scanning position of the liquid discharge head 200. The control signal Ctrl-H includes a head control signal, a change signal, a latch signal, and a clock signal.

[0024] The control circuit 11 generates a physical information request signal TD at a predetermined timing to acquire physical information such as temperature, humidity, and pressure of the liquid discharge head 200, and outputs it to the liquid discharge head 200. The control circuit 11 also receives a physical information signal TI output by the liquid discharge head 200 in response to the physical information request signal TD. Furthermore, the control circuit 11 corrects the control signals Ctrl-H, Ctrl-C, and Ctrl-T based on the physical information signal TI. The control circuit 11 may also stop the operation of the liquid discharge device 100 based on the physical information signal TI.

[0025] The control circuit 11 outputs a base drive signal dO, which is a digital signal, to the drive circuit 12. The drive circuit 12 converts the base drive signal dO to an analog signal, amplifies it to generate a drive signal COM, and outputs the drive signal COM to the liquid discharge head 200.

[0026] The reference voltage signal output circuit 13 generates a reference voltage signal VBS and outputs it to the liquid discharge head 200. The reference voltage signal VBS is a constant potential signal that serves as a reference for driving the piezoelectric element E, described later, which is located in the liquid discharge head 200. The reference voltage signal VBS is, for example, the ground potential or a DC voltage signal with a constant potential.

[0027] The liquid discharge head 200 includes liquid discharge modules 20-1 to 20-n and a physical information output circuit 25. Each of the liquid discharge modules 20-1 to 20-n also includes a drive signal selection circuit 21, an analog signal detection circuit 22, and piezoelectric elements E-1 to Em.

[0028] The liquid discharge modules 20-1 to 20-n receive the control signal Ctrl-H, the drive signal COM, and the reference voltage signal VBS. Specifically, the control signal Ctrl-H and the drive signal COM are input to the drive signal selection circuit 21. Based on the control signal Ctrl-H, the drive signal selection circuit 21 generates drive signals Vout-1 to Vout-m by selecting or deselecting the signal waveform of the drive signal COM. Note that drive signal Vout-1 corresponds to piezoelectric element E-1, and drive signal Vout-m corresponds to piezoelectric element Em. The drive signal selection circuit 21 individually inputs drive signals Vout-1 to Vout-m to one end of the corresponding piezoelectric elements E-1 to Em. In addition, the reference voltage signal VBS is commonly input to the other end of piezoelectric elements E-1 to Em. Piezoelectric elements E-1 to Em are driven by the potential difference between the drive signals Vout-1 to Vout-m and the reference voltage signal VBS. Then, an amount of liquid is dispensed according to the drive of each piezoelectric element E-1 to Em. Note that n and m are natural numbers.

[0029] Note that liquid dispensing modules 20-1 to 20-n all have the same configuration and may be referred to as liquid dispensing module 20 when there is no need to distinguish between them. Piezoelectric elements E-1 to Em all have the same configuration and may be referred to as piezoelectric element E when there is no need to distinguish between them. Drive signals Vout-1 to Vout-m may be referred to as drive signal Vout, corresponding to piezoelectric element E.

[0030] The analog signal detection circuit 22 detects analog signals TH-1 to TH-n corresponding to physical information such as temperature, humidity, and pressure of the liquid discharge modules 20-1 to 20-n, and outputs them to the physical information output circuit 25. In other words, the analog signal detection circuit 22 is a physical information detection unit that detects physical information such as temperature, humidity, and pressure of the liquid discharge module 20. Therefore, for example, if the physical information is temperature, the analog signal detection circuit 22 corresponds to a "temperature detection unit" that detects the temperature of the pressure chamber C1 of the liquid discharge module 20, which will be described later.

[0031] If liquid discharge modules 20-1 to 20-n are not distinguished, the signal detected by the analog signal detection circuit 22 is referred to as the analog signal TH.

[0032] The physical information output circuit 25 receives analog signals TH-1 to TH-n and a physical information request signal TD as inputs. The physical information output circuit 25 amplifies and holds each of the analog signals TH-1 to TH-n. Then, in response to the physical information request signal TD, the physical information output circuit 25 outputs the corresponding signal from among the amplified signals of the held analog signals TH-1 to TH-n as the physical information signal TI. The physical information output circuit 25 includes an amplification circuit for amplifying the analog signals TH-1 to TH-n, a processor such as a microcomputer that outputs the physical information signal TI, and a memory circuit for holding the analog signals TH-1 to TH-n.

[0033] 1-2. Liquid dispensing head 200 Figure 3 is an exploded perspective view of the liquid discharge head 200 shown in Figure 2. The liquid discharge head 200 shown in Figure 3 comprises a filter section 59, a communication member 54, a wiring board 27, a liquid distribution section 60, and a plurality of liquid discharge modules 20. The filter section 59, the communication member 54, the wiring board 27, the liquid distribution section 60, and the plurality of liquid discharge modules 20 are arranged in this order in the Z1 direction.

[0034] The liquid dispensing modules 20, in the illustrated example, consist of six liquid dispensing modules 20. The liquid dispensing modules 20 are spaced apart from each other and arranged along the X-axis. Each liquid dispensing module 20 includes a flexible printed circuit board 4.

[0035] The filter section 59 is an element that removes air bubbles and foreign matter contained in the liquid supplied from the liquid container 9. The filter section 59 is a flat plate made of resin material. The filter section 59 is also provided with four filters 596, for example, depending on the type of liquid. The filter section 59 is also provided with four supply ports SI3 for supplying the liquid 9 from the liquid container 9 to the filter section 59.

[0036] The connecting member 54 is a flat plate made of an elastic material. The connecting member 54 has multiple through holes 542 through which the liquid from the filter section 59 flows.

[0037] The wiring board 27 is a board on which wiring is formed for transmitting drive signals and power supply voltage to each liquid discharge module 20. The wiring board 27 is provided in common for multiple liquid discharge modules 20. For example, the physical information output circuit 25 shown in Figure 2 is mounted on the wiring board 27. In addition, the wiring board 27 has connection terminals (not shown) to which the flexible printed circuit boards 4 of each liquid discharge module 20 are electrically connected, and the wiring board 27 and the flexible printed circuit boards 4 are electrically connected.

[0038] The liquid distribution unit 60 is a component that distributes the liquid supplied through the through-holes 542 of the communication member 54 to each liquid discharge module 20. The liquid distribution unit 60 is composed of a laminate of multiple flat plate members. The liquid distribution unit 60 is made of a resin material. The liquid distribution unit 60 is also provided with a through-hole 60C through which the flexible printed circuit board 4 is inserted.

[0039] Note that the liquid discharge head 200 in Figure 3 is just an example, and additional elements may be added to or omitted from the liquid discharge head 200. For example, the holder 29 and the distribution channel member 28 may be integrated. Furthermore, the arrangement of the elements of the liquid discharge head 200 is not limited to the example in Figure 3. For example, the wiring board 27 may be located to the side of multiple liquid discharge modules 20.

[0040] 1-3. Liquid Dispensing Module 20 Figure 4 is a cross-sectional view showing the liquid ejection module 20 of Figure 3. Figure 5 is an exploded perspective view of the head chip 3 of the liquid ejection module 20 of Figure 4. As mentioned above, the liquid ejection module 20 includes the head chip 3 and the flexible printed circuit board 4. The Z-axis is the axis along the direction of liquid ejection by the liquid ejection head 200.

[0041] As illustrated in Figure 5, the head tip 3 of the liquid discharge module 20 is equipped with a plurality of nozzles N arranged along the Y-axis. The plurality of nozzles N are divided into a first nozzle row La and a second nozzle row Lb, which are spaced apart from each other and arranged side by side along the X-axis. The second nozzle row Lb is arranged side by side in the direction along the first nozzle row La. Each of the first nozzle row La and the second nozzle row Lb is a set of a plurality of nozzles N arranged linearly along the Y-axis. The liquid discharge module 20 has a structure in which the elements associated with each nozzle N in the first nozzle row La and the elements associated with each nozzle N in the second nozzle row Lb are arranged substantially symmetrically. In the following description, the elements corresponding to the first nozzle row La will be described in detail, and the description of the elements corresponding to the second nozzle row Lb will be omitted as appropriate.

[0042] As illustrated in Figures 3 and 4, the head chip 3 comprises a channel forming substrate 31, a pressure chamber substrate 32, a diaphragm 33, a nozzle substrate 37, a vibration absorber 38, a plurality of piezoelectric elements E, a sealant 35, and a channel housing 36. Each of the channel forming substrate 31, pressure chamber substrate 32, diaphragm 33, nozzle substrate 37, vibration absorber 38, sealant 35, and channel housing 36 is a long, plate-shaped member along the Y-axis. The nozzle substrate 37, channel forming substrate 31, pressure chamber substrate 32, diaphragm 33, and sealant 35 are arranged in this order in the Z2 direction. The diaphragm 33 and the plurality of piezoelectric elements E constitute the piezoelectric substrate 30.

[0043] The nozzle substrate 37 is a plate-shaped member on which a plurality of nozzles N are formed. The nozzle substrate 37 includes a first nozzle row La and a second nozzle row Lb. Each of the plurality of nozzles N is a circular through-hole for discharging liquid. The nozzle substrate 37 is bonded to the Z1 direction surface of the flow path forming substrate 31, for example, by an adhesive.

[0044] The channel-forming substrate 31 forms channels through which liquid flows. Specifically, the channel-forming substrate 31 has a space Ra, an intermediate liquid chamber Rb, a plurality of supply channels 312, and a plurality of communication channels 314. Space Ra is an elongated opening formed along the Y-axis. Each of the supply channels 312 and communication channels 314 is a through-hole formed for each nozzle N. Each communication channel 314 overlaps a corresponding nozzle N in a plan view from the Z1 direction. The intermediate liquid chamber Rb is an elongated space formed along the Y-axis across multiple nozzles N, and connects space Ra and the plurality of supply channels 312 to each other. A pressure chamber substrate 32 is bonded to the Z2 direction surface of the channel-forming substrate 31 with adhesive.

[0045] The pressure chamber substrate 32 is connected to the piezoelectric substrate 30. The pressure chamber substrate 32 is provided with a pressure chamber C1 whose volume changes due to the deformation of the piezoelectric substrate 30. The pressure chamber substrate 32 can also be considered to partition the pressure chamber C1. The pressure chamber substrate 32 is made of silicon oxide. Liquid discharged from the nozzle N is stored in the pressure chamber C1. The pressure chamber C1 is located between the nozzle substrate 37 and the diaphragm 33 and is a space formed by the inner wall surface of the pressure chamber substrate 32. A pressure chamber C1 is formed for each nozzle N. The pressure chamber C1 is an elongated space and extends in the X1 direction. Multiple pressure chambers C1 are arranged along the Y axis. Each pressure chamber C1 communicates with the communication channel 314 and the supply channel 312. Therefore, the pressure chamber C1 communicates with the nozzle N via the communication channel 314 and with the space Ra via the supply channel 312 and the intermediate liquid chamber Rb.

[0046] The nozzle substrate 37, the channel-forming substrate 31, and the pressure chamber substrate 32 are manufactured by processing a silicon (Si) single crystal substrate using semiconductor manufacturing technologies such as photolithography and etching. However, known materials and manufacturing methods can be arbitrarily used for the manufacture of the nozzle substrate 37, the channel-forming substrate 31, and the pressure chamber substrate 32.

[0047] The diaphragm 33 of the piezoelectric substrate 30 is connected to the surface of the pressure chamber substrate 32 opposite to the flow channel forming substrate 31. The diaphragm 33 is positioned on the pressure chamber C1 and is elastically deformable. The diaphragm 33 vibrates when driven by the piezoelectric element E. The diaphragm 33 is a plate-like member formed in a long rectangular shape along the Y-axis in a plan view. The diaphragm 33 and the pressure chamber may be an integrated structure, or they may be separate structures joined together with an adhesive or the like.

[0048] A piezoelectric element E is formed on the surface of the diaphragm 33 opposite to the pressure chamber C1. A piezoelectric element E is provided for each pressure chamber C1. The piezoelectric element E is elongated in length along the X-axis in a plan view. The piezoelectric element E is a driving element that is driven when a driving signal is applied, and it applies pressure to the liquid in the pressure chamber C1.

[0049] The seal 35 is bonded to the diaphragm 33, for example, by adhesive. The seal 35 is a structure that protects multiple piezoelectric elements E and reinforces the mechanical strength of the pressure chamber substrate 32 and the diaphragm 33. A recess is formed in the seal 35 on the surface facing the diaphragm 33. Multiple piezoelectric elements E are housed inside this recess. The seal 35 also has a space 353 through which the flexible printed circuit board 4 is inserted.

[0050] Furthermore, a vibration absorber 38 is bonded to the Z1-direction surface of the channel-forming substrate 31, for example, by an adhesive. The vibration absorber 38 is a flexible film that constitutes the wall surface of space Ra.

[0051] The flow path housing 36 is joined to the flow path forming substrate 31, for example, by an adhesive. The flow path housing 36 is a case for storing liquid supplied to a plurality of pressure chambers C1. The flow path housing 36 is formed, for example, by injection molding of a resin material. The flow path housing 36 has a space Rc, a supply port 361, and a space 362. The supply port 361 is a conduit through which liquid is supplied from the liquid container 9 via the distribution flow path member 28, and communicates with space Rc. Space Rc communicates with space Ra of the flow path forming substrate 31. The space composed of space Rc and space Ra functions as a liquid storage chamber R for storing liquid supplied to the plurality of pressure chambers C1. Liquid supplied from the liquid container 9 and passing through the supply port 361 is stored in the liquid storage chamber R. The liquid stored in the liquid storage chamber R branches from the relay liquid chamber Rb to each supply flow path 312 and is supplied in parallel to the plurality of pressure chambers C1. Furthermore, space 362 overlaps with space 353 of the encapsulant 35 in a plan view. The flexible printed circuit board 4 is inserted through spaces 353 and 362.

[0052] The flexible printed circuit board 4 is connected to the diaphragm 33. The flexible printed circuit board 4 electrically connects the piezoelectric substrate 30 and the wiring substrate 27. The flexible printed circuit board 4 is a mounting component with multiple wirings formed on it. For example, the flexible printed circuit board 4 is an FPC (Flexible Printed Circuit) or COF (Chip On Film), and is a flexible circuit board. The drive signal selection circuit 21 shown in Figure 2 is mounted on the flexible printed circuit board 4.

[0053] In this liquid discharge module 20, when the piezoelectric element E is deflected by the application of voltage, the diaphragm 33 deflects, i.e., vibrates, in a direction that reduces the volume of the pressure chamber C1. As a result, the pressure in the pressure chamber C1 changes, and the liquid in the pressure chamber C1 is discharged from the nozzle N. After the liquid is discharged, the piezoelectric element E returns to its original position.

[0054] Furthermore, although the liquid discharge module 20 includes all the elements shown in Figures 4 and 5, the components of the liquid discharge module 20 do not necessarily have to include all of these elements, and may also include additional elements.

[0055] 1-3. Piezoelectric substrate 30 Figures 6 and 7 are cross-sectional views showing the piezoelectric substrate 30 of Figure 5, respectively. Figure 8 is a plan view of the piezoelectric substrate 30 of Figure 5.

[0056] In the examples shown in Figures 6 and 7, the diaphragm 33 of the piezoelectric substrate 30 is composed of a laminate including a first layer 331 and a second layer 332. The first layer 331 is in contact with the pressure chamber substrate 32. The second layer 332 is positioned above the first layer 331. The second layer 332 is located closer to the piezoelectric element E than the first layer 331. The second layer 332 is made of zirconium oxide (ZrO x It is formed of an insulating material such as ). The first layer 331 is formed, for example, by thermal oxidation of a part of the pressure chamber substrate 32. The second layer 332 is formed, for example, by known film deposition techniques such as sputtering. The diaphragm 33 may consist of one layer or three or more layers.

[0057] The piezoelectric element E mainly comprises individual electrodes 51, a piezoelectric layer 53, and a common electrode 52. The individual electrodes 51, the piezoelectric layer 53, and the common electrode 52 are stacked in a direction along the Z-axis, which is the stacking direction. The piezoelectric layer 53 also has a plurality of piezoelectric parts 531. Note that the piezoelectric layer 53 is not shown in Figure 8.

[0058] The individual electrodes 51 are provided above the diaphragm 33. Each individual electrode 51 is an individual electrode provided for each piezoelectric element E. A drive signal Vout is applied to the individual electrodes 51. The individual electrodes 51 are elongated in shape along the X-axis. Multiple individual electrodes 51 are arranged along the Y-axis with spacing between them. The individual electrodes 51 contain a conductive material such as metal.

[0059] The piezoelectric layer 53 is provided above the individual electrodes 51. The piezoelectric layer 53 is, for example, a strip-shaped dielectric film that is continuous along the Y-axis across the plurality of piezoelectric elements E. The piezoelectric layer 53 is, for example, a strip extending along the Y-axis and is separated for each piezoelectric element E by forming a plurality of notches. Due to the formation of a plurality of notches, the piezoelectric layer 53 has a plurality of piezoelectric portions 531. The aforementioned plurality of individual electrodes 51 are provided corresponding to the plurality of piezoelectric portions 531. The piezoelectric layer 53 is composed of, for example, a piezoelectric material having a perovskite-type crystal structure.

[0060] Examples of the piezoelectric material include lead titanate (PbTiO3), lead zirconate titanate (PZT: Pb(Zr,Ti)O3), lead zirconate (PbZrO3), lead lanthanum titanate ((Pb,La),TiO3), lead lanthanum zirconate titanate ((Pb,La)(Zr,Ti)O3), lead zirconium niobate titanate (Pb(Zr,Ti,Nb)O3), and lead zirconium magnesium niobate titanate (Pb(Zr,Ti)(Mg,Nb)O3). Among these, lead zirconate titanate (PZT) is preferably used as the constituent material of the piezoelectric layer 53.

[0061] The common electrode 52 is provided above the piezoelectric layer 53. The common electrode 52 is a strip-shaped common electrode that extends along the Y-axis so as to be continuous across multiple piezoelectric elements E. The common electrode 52 is provided in common with the multiple piezoelectric parts 531 mentioned above. A reference voltage signal VBS is applied to the common electrode 52. The common electrode 52 contains a conductive material such as metal.

[0062] A voltage equivalent to the difference between the reference voltage signal VBS applied to the common electrode 52 and the drive signal Vout corresponding to the discharge amount supplied to the individual electrodes 51 is applied to the piezoelectric unit 531. When a voltage is applied between the individual electrodes 51 and the common electrode 52, the piezoelectric unit 531 deforms, causing the piezoelectric element E to bend and deform, i.e., vibrate.

[0063] Furthermore, a weight portion 380 is provided above the common electrode 52, in contact with the common electrode 52. As shown in Figure 8, the weight portion 380 is in the shape of a rectangular frame. The weight portion 380 functions as a weight to suppress excessive vibration of the diaphragm 33. A connecting electrode 381 is also connected to the weight portion 380. The connecting electrode 381 is connected to the flexible printed circuit board 4. A reference voltage signal VBS is applied to the aforementioned common electrode 52 via the connecting electrode 381 and the weight portion 380. The weight portion 380 contains a metal, such as gold.

[0064] Furthermore, as shown in Figures 6 and 8, a connecting electrode 39 is connected to each of the individual electrodes 51. The connecting electrode 39 is connected to the flexible printed circuit board 4. A drive signal Vout is applied to the individual electrodes 51 via the connecting electrode 39. The connecting electrode 39 contains a metal, such as gold.

[0065] In the examples shown in Figures 6 and 7, individual electrodes 51 are provided below the piezoelectric layer 53, and a common electrode 52 is provided above the piezoelectric layer 53. However, the common electrode 52 may be provided below the piezoelectric layer 53, and the individual electrodes 51 may be provided above the piezoelectric layer 53.

[0066] 1-4. Flexible Printed Circuit Board 4 Figure 9 shows the flexible printed circuit board 4 shown in Figure 4. Figure 10 is a perspective view showing a part of the flexible printed circuit board 4 shown in Figure 9, and is an enlarged view of area A in Figure 9. Figure 11 shows the mounting area 271 of the flexible printed circuit board 4 shown in Figure 9.

[0067] The length of the flexible printed circuit board 4 along the Y-axis is approximately equal to, for example, the length from one end to the other of the first nozzle row La. As shown in Figure 4, a portion of the flexible printed circuit board 4 is connected to the piezoelectric substrate 30, and the remainder extends from the piezoelectric substrate 30 in the Z2 direction. As shown in Figure 10, the flexible printed circuit board 4 has a mounting area 271, a non-mounting area 272, and a curved portion 273. The flexible printed circuit board 4 also has a region at its Z2 end that is connected to the wiring board 27.

[0068] The mounting area 271 is the portion connected to the piezoelectric substrate 30 and extends in the XY plane. The non-mounted area 272 is the portion not directly connected to the piezoelectric substrate 30. The non-mounted area 272 extends in the YZ plane and extends from the piezoelectric substrate 30 in the Z1 direction. Mounted components 275, as shown in Figure 9, are provided in the non-mounted area 272. Mounted components 275 include, for example, the drive signal selection circuit 21 and the analog signal detection circuit 22 shown in Figure 2. Also, as shown in Figure 10, the curved portion 273 is the boundary portion between the mounting area 271 and the non-mounted area 272. The curved portion 273 is the portion that is bent at approximately 90 degrees so that the flexible printed circuit board 4 is curved.

[0069] The flexible printed circuit board 4 comprises a base material 270, a plurality of wirings 411, a plurality of drive signal wirings 41, a plurality of constant voltage wirings 42, a plurality of second constant voltage wirings 43, an analog signal wiring 44, a second analog signal wiring 45, and mounted components 275. Figure 9 shows some of the various wirings on the flexible printed circuit board 4, but the detailed illustration of the area around the mounted components 275 among the various wirings is omitted because it would complicate understanding.

[0070] The flexible printed circuit board 4 does not necessarily have to have mounted components 275. In this case, the drive signal selection circuit 21 and the analog signal detection circuit 22 are provided on the wiring board 27 to which one end of the flexible printed circuit board 4 is connected, or on another board. In this case, multiple drive signal wires 41 are electrically connected to the wiring board 27.

[0071] The base material 270 is an insulator formed from a resin such as polyimide. The base material 270 is a flexible film-like member. Multiple drive signal wires 41, multiple constant voltage wires 42, multiple second constant voltage wires 43, analog signal wires 44, and second analog signal wires 45 are formed on the base material 270. These wires are covered in an insulator formed from a resin such as polyimide in the non-mounted area 272. The directions in which the multiple drive signal wires 41, multiple constant voltage wires 42, multiple second constant voltage wires 43, analog signal wires 44, and second analog signal wires 45 are arranged are approximately the same, and are approximately along the Z-axis.

[0072] The multiple wirings 411 are positioned in the Z2 direction relative to the multiple drive signal wirings 41. The multiple wirings 411 are located in the central part of the base material 270 along the Y axis. The multiple wirings 411 are spaced apart from each other and aligned along the Y axis. The multiple wires 411 connect to the wiring board 27 and the mounted component 275, and are input-side wires for inputting input signals (e.g., drive signal COM, latch signal, clock signal) to the mounted component 275. The multiple wires 411 may also include wires used as power supply voltages for various configurations of the mounted component 275 and the liquid discharge module 20.

[0073] Multiple drive signal wires 41 are located in the Z1 direction on the base material 270 and are provided in the central part of the base material 270 along the Y axis. The multiple drive signal wires 41 are spaced apart from each other and aligned along the Y axis. The direction along the Y axis corresponds to the "first direction". The multiple drive signal wires 41 are output-side wires that connect to the mounted component 275 and send drive signals Vout to the multiple piezoelectric elements E. The multiple drive signal wires 41 correspond one-to-one with the multiple individual electrodes 51.

[0074] The constant voltage wiring 42 and the second constant voltage wiring 43 are located on the outside of the base material 270 in the Y-axis direction, and are arranged to sandwich the group of multiple drive signal wirings 41 in the Y-axis direction. In addition, the constant voltage wiring 42 and the second constant voltage wiring 43 are arranged to sandwich the group of multiple wirings 411 in the Y-axis direction. The constant voltage wiring 42 and the second constant voltage wiring 43 are not connected to the mounted components 275, but are arranged to connect the input side located in the Z2 direction to the output side located in the Z1 direction of the flexible printed circuit board 4. The constant voltage wiring 42 and the second constant voltage wiring 43 are a single wire on the input side in the Z2 direction and in the non-mounted area 272, but are divided into multiple wires in the mounted area 271. For example, the constant voltage wiring 42 and the second constant voltage wiring 43 are divided into eight wires in the mounted area 271. The divided multiple constant voltage wirings 42 and multiple second constant voltage wirings 43 are spaced apart from each other and aligned along the Y axis.

[0075] Because the constant voltage wiring 42 and the second constant voltage wiring 43 are divided into multiple wirings in the mounting area 271, the surface area to which adhesive adheres when multiple wirings are connected can be increased. As a result, the flexible printed circuit board 4 becomes less likely to peel off from the piezoelectric substrate 30, and disconnection of the constant voltage wiring 42 and the second constant voltage wiring 43 can be suppressed. Furthermore, because the constant voltage wiring 42 and the second constant voltage wiring 43 are divided into multiple wirings in the mounting area 271, it is possible to suppress contact failure even if misalignment occurs when connecting to the connecting electrode 381 of the piezoelectric substrate 30 in the mounting area 271.

[0076] Furthermore, the width of one constant voltage wiring 42 and the width of one second constant voltage wiring 43 in the mounting area 271 may be equal to the width of the drive signal wiring 41. Also, the distance between multiple constant voltage wirings 42 and the distance between multiple second constant voltage wirings 43 in the mounting area 271 may be equal to the distance between multiple drive signal wirings 41. In this case, the surface area to which the adhesive adheres to the constant voltage wiring 42, second constant voltage wiring 43, and drive signal wiring 41 becomes equal, and variations in adhesion between wiring can be suppressed.

[0077] In this explanation, the constant voltage wiring 42 and the second constant voltage wiring 43 in the implementation area 271 may be referred to as multiple constant voltage wirings 42 and multiple second constant voltage wirings 43. Furthermore, the number of constant voltage wirings 42 and second constant voltage wirings 43 in the mounting area 271 is not limited to eight; it may be one or more. Multiple constant voltage wirings 42 and multiple second constant voltage wirings 43 may be formed extending from the mounting area 271 to the non-mounting area 272. In addition, the constant voltage wirings 42 and second constant voltage wirings 43 may be divided into multiple wirings on the input side located in the Z2 direction. Furthermore, the width of the constant voltage wiring 42 and the second constant voltage wiring 43 in the mounting area 271, as well as the distance between the wirings, may be set arbitrarily.

[0078] Each of the constant voltage wiring 42 and the second constant voltage wiring 43 is maintained at a constant voltage. A reference voltage signal VBS is applied to each of the constant voltage wiring 42 and the second constant voltage wiring 43. Multiple constant voltage wirings 42 and multiple second constant voltage wirings 43 are electrically connected to a common electrode 52.

[0079] The analog signal wiring 44 is located outside the constant voltage wiring 42. The second analog signal wiring 45 is a different wiring from the analog signal wiring 44 and is located outside the second constant voltage wiring 43. Both the analog signal wiring 44 and the second analog signal wiring 45 transmit the analog signal TH. Note that there may be two or more analog signal wirings 44. Similarly, there may be two or more second analog signal wirings 45.

[0080] The materials for the multiple drive signal wirings 41, multiple constant voltage wirings 42, multiple second constant voltage wirings 43, analog signal wirings 44, and second analog signal wirings 45 are not particularly limited as long as they are conductive materials, and include metals such as gold (Au), copper (Cu), titanium (Ti), tungsten (W), nickel (Ni), chromium (Cr), platinum (Pt), and aluminum (Al).

[0081] As shown in Figures 9-11, the constant voltage wiring 42 is arranged between multiple drive signal wirings 41 and analog signal wirings 44 in the direction along the Y-axis, which is the "first direction" intersecting the direction in which the constant voltage wiring 42 is arranged. The second analog signal wiring 45 has the same configuration as the analog signal wiring 44, so it is not shown. Furthermore, the following description will focus on the analog signal wiring 44. The second analog signal wiring 45 exhibits the same function and effect as the analog signal wiring 44.

[0082] Each drive signal wire 41 is a wire that sends a drive signal Vout to the piezoelectric element E. Therefore, noise is easily generated around multiple drive signal wires 41. Consequently, if an analog signal wire 44 is adjacent to a drive signal wire 41, noise generated from the drive signal wire 41 is easily superimposed on the analog signal wire 44. In particular, in this embodiment, a voltage of approximately 43V is applied to the drive signal wire 41, while a voltage of approximately 3V is applied to the analog signal wire 44. Therefore, if they are adjacent, the analog signal wire 44 is susceptible to noise from the drive signal wire 41. In contrast, in this embodiment, a constant voltage wiring 42 is arranged between the drive signal wiring 41 and the analog signal wiring 44. Therefore, the constant voltage wiring 42 functions as a noise shield. Consequently, it is possible to suppress noise generated from the drive signal wiring 41 from being superimposed on the analog signal wiring 44. Thus, a wiring design method with high signal transmission accuracy in the analog signal wiring 44 can be provided.

[0083] Similarly, the second constant voltage wiring 43 is arranged in the direction along the Y-axis, sandwiched between the drive signal wiring 41 and the second analog signal wiring 45. Therefore, the second constant voltage wiring 43 functions as a noise shield. Thus, it is possible to suppress noise generated from the drive signal wiring 41 from being carried over to the second analog signal wiring 45.

[0084] In this embodiment, the drive signal wiring 41 is subjected to a voltage of approximately 43V, the analog signal wiring 44 and the second analog signal wiring 45 are subjected to a voltage of approximately 3V, and the constant voltage wiring 42 and the second constant voltage wiring 43 are subjected to a constant voltage of approximately 5V, but this is not limited to these values. The voltage applied to each wiring can be set arbitrarily. In addition, the constant voltage wiring 42 and the second constant voltage wiring 43 may be wiring connected to GND or wiring to which a constant voltage is applied, such as the power supply voltage for various configurations.

[0085] Furthermore, along the Y-axis, the multiple drive signal wires 41 are sandwiched between the constant voltage wire 42 and the second constant voltage wire 43. This makes it possible to more effectively suppress noise generated in the multiple drive signal wires 41 from affecting the analog signal wire 44 and the second analog signal wire 45.

[0086] For example, the second analog signal wiring 45 does not need to be provided. In this case, the multiple drive signal wirings 41 do not need to be sandwiched between the constant voltage wiring 42 and the second constant voltage wiring 43. In this case, the analog signal wiring 44 only needs to be located outside the constant voltage wiring 42.

[0087] Furthermore, the second analog signal wiring 45 may be provided on the same side as the analog signal wiring 44 on the flexible printed circuit board 4. In this case, the analog signal wiring 44 and the second analog signal wiring 45 should be located outside the constant voltage wiring 42.

[0088] Furthermore, in the direction along the Y-axis, the flexible printed circuit board 4 has no other wiring between its edge 279 and the analog signal wiring 44; in other words, the analog signal wiring 44 is provided on the outermost edge of the flexible printed circuit board 4 along the Y-axis. The edge 279 is in a direction that intersects with the extending direction of the first nozzle row La and is an edge that extends along the YZ plane.

[0089] By placing the analog signal wiring 44 on the outermost part of the flexible printed circuit board 4, it is possible to suppress noise from other wiring from being superimposed on the analog signal wiring 44.

[0090] Similarly, in the direction along the Y-axis, the flexible printed circuit board 4 has no other wiring between its edge 279 and the second analog signal wiring 45; in other words, the second analog signal wiring 45 is provided on the outermost edge of the flexible printed circuit board 4 along the Y-axis. By providing the second analog signal wiring 45 on the outermost edge of the flexible printed circuit board 4, it is possible to suppress noise from other wiring from being superimposed on the second analog signal wiring 45.

[0091] Furthermore, the direction of the current flowing through each of the multiple drive signal wires 41 is opposite to the direction of the current flowing through the constant voltage wire 42 and the second constant voltage wire 43. As a result, the magnetic field generated from the current flowing through each drive signal wire 41 and the magnetic field generated from the current flowing through the constant voltage wire 42 and the second constant voltage wire 43 are in opposite directions and cancel each other out. As a result, noise generated from each drive signal wire 41 can be more effectively suppressed from being superimposed on the analog signal wire 44 and the second analog signal wire 45.

[0092] Furthermore, the piezoelectric substrate 30 preferably has 300 or more piezoelectric elements E. The more piezoelectric elements E there are, the more drive signal wiring 41 there are. In this case, the current flowing through the multiple drive signal wiring 41 becomes larger, and the sum of the noise increases. As a result, noise is more likely to be superimposed on the analog signal wiring 44 and the second analog signal wiring 45. Moreover, since the ON / OFF state of the current is set for each drive signal Vout of the piezoelectric elements E, noise is generated randomly. For this reason, when a large number of piezoelectric elements E are provided, such as 300 or more piezoelectric elements E, it is particularly beneficial to arrange constant voltage wiring 42 between the numerous drive signal wiring 41 and the analog signal wiring 44, and to arrange a second constant voltage wiring 43 between the numerous drive signal wiring 41 and the second analog signal wiring 45.

[0093] Furthermore, the number of piezoelectric elements E may be less than 300.

[0094] Furthermore, in the mounting area 271, the width of the analog signal wiring 44 is greater than the width of the constant voltage wiring 42. This width is the width when the flexible printed circuit board 4 is viewed from above. By making the width of the analog signal wiring 44 greater than the width of each constant voltage wiring 42, the durability of the flexible printed circuit board 4 against stress when connecting it to the piezoelectric substrate 30 can be improved. By increasing the width of the analog signal wiring 44, which is the outer region of the flexible printed circuit board 4, the contact area between the analog signal wiring 44 and the piezoelectric substrate 30 is increased. As a result, the rigidity of the outer part of the flexible printed circuit board 4 can be increased, thereby increasing the rigidity of the entire mounting area 271 of the flexible printed circuit board 4. Thus, peeling or lifting of the flexible printed circuit board 4 from the piezoelectric substrate 30 can be suppressed, and disconnection can be suppressed. In addition, stress can be suppressed on the constant voltage wiring 42 and the multiple drive signal wiring 41 which are located inside the analog signal wiring 44.

[0095] Figure 12 shows the mounting area 271 and its vicinity when the flexible printed circuit board 4 shown in Figure 9 is not bent. As shown in Figure 12, the mounting area 271 includes a first area S1, a second area S2, and a third area S3. The first area S1 is the area where multiple drive signal wirings 41 are arranged. The second area S2 is the area where analog signal wirings 44 are arranged. The third area S3 is the area where constant voltage wirings 42 are arranged. The first area S1, the third area S3, and the second area S2 are arranged in this order along the Y-axis. The second area S2 is located furthest out along the Y-axis.

[0096] Furthermore, the second region S2 is smaller than the first region S1. The larger size of the second region S2 allows for the arrangement of a large number of drive signal wires 41 on the base material 270, such as more than 300 drive signal wires 41.

[0097] Furthermore, the planar area of ​​the second region S2 is smaller than the size, i.e., the planar area, of the third region S3.

[0098] Furthermore, in the non-mounted area 272, the width of the analog signal wiring 44 may be smaller than the width of the constant voltage wiring 42. In this case, since the width of the constant voltage wiring 42 is larger than the width of the analog signal wiring 44 in the non-mounted area 272, noise generated from the drive signal wiring 41 can be further suppressed from being superimposed on the analog signal wiring 44 in the non-mounted area 272.

[0099] Furthermore, the analog signal wiring 44 has a first part 441 and a second part 442 in the mounting area 271. The first part 441 has a first width W1 which is the length along the Y axis. The second part 442 is located at the end 2710 of the mounting area 271, which is the end side of the mounting area 271 opposite to the curved part 273. The second part 442 also has a second width W2 which is narrower than the first width W1.

[0100] The wide first section 441 allows for more reliable connection between the analog signal wiring 44 and the piezoelectric substrate 30 in the mounting area 271. In particular, the analog signal wiring 44 is located on the outermost side along the Y-axis of the flexible printed circuit board 4 and is susceptible to misalignment during mounting of the flexible printed circuit board 4, as well as peeling or lifting of the flexible printed circuit board 4. By providing the wide first section 441, a more reliable connection can be achieved even if misalignment occurs. Furthermore, because the connection is more reliable, the contact resistance generated in the first section 441 can be reduced. Furthermore, by making the second width W2 of the second part 442 narrower than the first width W1 of the first part 441, the amount of material used for the second part 442 can be reduced.

[0101] Note that the width of section 441 in Part 1 and section 442 in Part 2 may be the same.

[0102] Furthermore, the constant voltage wiring 42 is exposed to the outside at end 2710, which is the side surface of one end of the flexible printed circuit board 4. Similarly, the second part 442 of the analog signal wiring 44 is exposed to the outside at end 2710. And, in the direction along the Y axis, the distance L2 between the second part 442 and the constant voltage wiring 42 is greater than the distance L1 between the first part 441 and the constant voltage wiring 42.

[0103] The end portion 2710 of the flexible printed circuit board 4 is formed by cutting the board after the analog signal wiring 44 has been laid on the base material 270 and the process inspection has been completed. In this case, a portion of the analog signal wiring 44 is exposed, and burrs may be generated on the cut surface of the end portion 2710. Various wirings such as the analog signal wiring 44 contain metals such as Cu and are easily oxidized. Therefore, if an oxide film is formed on the burrs and the formation of the oxide film progresses, there is a risk that a portion of the analog signal wiring 44 and the constant voltage wiring 42 may become electrically connected. Therefore, by increasing the distance between the second portion 442 of the analog signal wiring 44 and the constant voltage wiring 42, the aforementioned risk of electrical connection can be suppressed.

[0104] On the other hand, since no burrs are generated in part 1 441, there is no risk of electrical connection between part 1 441 and the constant voltage wiring 42. Therefore, by making the distance L1 between part 1 441 and the constant voltage wiring 42 smaller than the distance L2, the distance between the analog signal wiring 44 and the constant voltage wiring 42 can be reduced, and the flexible printed circuit board 4 can be miniaturized.

[0105] The distance L2 between the second part 442 and the constant voltage wiring 42 may be less than or equal to the distance L1 between the first part 441 and the constant voltage wiring 42.

[0106] Furthermore, the analog signal wiring 44 has a third section 443. The third section 443 is connected to the first section 441. The third section 443 has a third width W3 which is narrower than the first width W1 of the first section 441. The third width W3 is wider than the width W20 of the constant voltage wiring 42. The third width W3 is wider than the second width W2.

[0107] By making the width of the first part 441 located in the mounting area 271 larger than the width of the third part 443 located in the non-mounting area 272, it is possible to suppress disconnection of various wirings when they peel off or lift from the base material 270 in the mounting area 271. In addition, by making the third part 443 narrower than the first part 441 located in the mounting area 271, the amount of material used for the analog signal wiring 44 can be reduced. Furthermore, by making the third width W3 of the third part 443, which is located outside the constant voltage wiring 42, larger than the constant voltage wiring 42, the durability of the flexible printed circuit board 4 can be increased.

[0108] Furthermore, the third width W3 of part 3 443 may be greater than or equal to the first width W1 of part 1 441. Also, the third width W3 of part 3 may be less than or equal to the width of the constant voltage wiring 42.

[0109] Furthermore, in the direction along the Y-axis, the second part 442 and the third part 443 are arranged asymmetrically with respect to the first part 441. Specifically, when the flexible printed circuit board 4 is not bent, the first part 441 is rectangular in plan view. The second part 442 is connected to one corner of the first part 441, and the third part 443 is connected to the corner of the first part 441 opposite to that corner. The distance L3 between the third part 443 and the constant voltage wiring 42 is smaller than the distance L2 between the second part 442 and the constant voltage wiring 42. By making the distance L3 between the third part 443 and the constant voltage wiring 42 shorter, the flexible printed circuit board 4 can be miniaturized. Also, by making the distance L2 between the second part 442 and the constant voltage wiring 42 larger, it is possible to suppress the second part 442 and the constant voltage wiring 42 from being electrically connected externally.

[0110] The distance L2 between the third part 443 and the constant voltage wiring 42 may be greater than or equal to the distance L2 between the second part 442 and the constant voltage wiring 42.

[0111] Furthermore, the first part 441 is provided across the curved portion 273. Therefore, the first part 441 extends outward from the mounting area 271. In this embodiment, the first part 441, which has a larger area, is located in the curved portion, rather than the second part 442 and the third part 443. Therefore, the rigidity of the flexible printed circuit board 4 can be ensured when the flexible printed circuit board 4 is bent. In addition, the presence of the first part 441 can suppress the bending back when the board is bent.

[0112] Part 1 441 does not have material that constitutes the analog signal wiring 44, and has an opening 44H provided in the analog signal wiring 44. The opening 44H functions as an alignment mark used for positioning when mounting the flexible printed circuit board 4 on the piezoelectric substrate 30. By providing the opening 44H, which is an alignment mark, in the analog signal wiring 44, the overall size of the flexible printed circuit board 4 can be reduced compared to a configuration in which it is provided separately in a location other than the analog signal wiring 44.

[0113] The opening 44H is a hole through which the analog signal wiring 44 passes, but does not penetrate the base material 270. However, the opening 44H may also penetrate the base material 270 in addition to the analog signal wiring 44. The alignment marks may be provided on parts of the base material 270 where no wiring is provided.

[0114] Furthermore, as shown in Figure 9, the substrate 270 is provided with two identification marks 2701 and two through holes 270H. Each identification mark 2701 is a thin film containing metal and is circular in the illustrated example. Each identification mark 2701 is provided, for example, to identify the flexible printed circuit board 4. Two through holes 270H are provided in a one-to-one correspondence with the two identification marks 2701. One corresponding through hole 270H is provided below each identification mark 2701.

[0115] Each through-hole 270H is a hole that penetrates the flexible printed circuit board 4. Each through-hole 270H is provided, for example, for positioning the flexible printed circuit board 4 with other components. In addition, a portion of the analog signal wiring 44 is arranged so as to surround one of the two through-holes 270H. The second analog signal wiring 45 is arranged so as to surround the other of the two through-holes 270H.

[0116] By arranging the analog signal wiring 44 around one of the through-holes 270H, the rigidity around the through-hole 270H can be increased. If the analog signal wiring 44 is made of metal plating, the area around the through-hole 270H is surrounded by the metal plating, thus preventing corrosion. Since the second analog signal wiring 45 is also provided around the other through-hole 270H, the same effect as described above can be obtained.

[0117] Note that the two identification marks 2701 and the two through holes 270H may be omitted as appropriate.

[0118] Furthermore, as shown in Figure 8, a first resistance wiring 46 and a second resistance wiring 47 are provided on the surface of the piezoelectric substrate 30 facing the Z2 direction. The first resistance wiring 46 is provided along the first nozzle row La in a plan view. The second resistance wiring 47 is provided along the second nozzle row Lb in a plan view. In this embodiment, one end of the first resistance wiring 46 and one end of the second resistance wiring 47 are connected to the analog signal wiring 44. The other end of the first resistance wiring 46 and the other end of the second resistance wiring 47 are connected to the second analog signal wiring 45. Therefore, the first resistance wiring 46 and the second resistance wiring 47 are connected in parallel.

[0119] The parallel connection of the first resistance wiring 46 and the second resistance wiring 47 allows for lower resistance compared to the case where the first resistance wiring 46 and the second resistance wiring 47 are connected in series. Therefore, the analog signal TH can be acquired with low power. Furthermore, since the first resistance wiring 46 is provided along the first nozzle row La and the second resistance wiring 47 is provided along the second nozzle row Lb, the average information of the first nozzle row La and the second nozzle row Lb can be acquired.

[0120] Furthermore, the first resistance wiring 46 and the second resistance wiring 47 may each be arranged in a part of the nozzle row. In addition, other resistance wiring may be provided in addition to the first resistance wiring 46 and the second resistance wiring 47.

[0121] Furthermore, the analog signal wiring 44 and the second analog signal wiring 45 are electrically connected to an analog signal detection circuit 22 provided on the flexible printed circuit board 4. When the analog signal detection circuit 22 is a "temperature detection unit", the ejection of the liquid ejection module 20 can be controlled to suit the temperature of the ink in the pressure chamber C1 using the analog signal TH. Also, ejection characteristics are easily affected by temperature. For this reason, it is preferable that the analog signal detection circuit 22 can detect minute changes in temperature. According to this embodiment, since a constant voltage wiring 42 is provided between the drive signal wiring 41 and the analog signal wiring 44, noise generated from the drive signal wiring 41 can be suppressed from being superimposed on the analog signal wiring 44. Similarly, since a second constant voltage wiring 43 is provided between the drive signal wiring 41 and the second analog signal wiring 45, noise generated from the drive signal wiring 41 can be suppressed from being superimposed on the second analog signal wiring 45. Therefore, minute changes in temperature can be detected based on the signal output from the analog signal detection circuit 22.

[0122] The resistance value of the first resistance wiring 46 is prone to change in response to temperature changes in the multiple pressure chambers C1 corresponding to the first nozzle row La. The resistance value of the second resistance wiring 47 is prone to change in response to temperature changes in the multiple pressure chambers C1 corresponding to the second nozzle row Lb. When the analog signal detection circuit 22 is a "temperature detection unit", the analog signal detection circuit 22 outputs an analog signal TH relating to the resistance values ​​of the first resistance wiring 46 and the second resistance wiring 47 as a physical information signal TI relating to temperature.

[0123] Furthermore, the first resistance wiring 46 and the second resistance wiring 47 are arranged in a bellows-like manner so as to reciprocate multiple times along the Y-axis. As a result, the wiring length of the first resistance wiring 46 and the second resistance wiring 47 is increased, making it possible to increase the resistance of the first resistance wiring 46 and the second resistance wiring 47.

[0124] Furthermore, in the implementation area 271, the widths of the first resistor wiring 46 and the second resistor wiring 47 are smaller than the first part 441 of the analog signal wiring 44. By using such wiring widths, the resistance values ​​of the first resistor wiring 46 and the second resistor wiring 47 can be made larger than the values ​​of other resistors present on the detection circuit, such as contact resistance.

[0125] Because the analog signal wiring 44 is located on the outermost edge of the flexible printed circuit board 4 along the Y-axis, it is susceptible to misalignment, peeling, and lifting in the mounting area when mounting the flexible printed circuit board 4. In addition, since the wiring width of the first resistance wiring 46 and the second resistance wiring 47 is reduced in order to increase their resistance, if misalignment, peeling, or lifting occurs in the mounting area 271, the contact resistance between the analog signal wiring 44 and the first resistance wiring 46 and the second resistance wiring 47 may increase.

[0126] Figure 13 is a diagram illustrating the connection state between the various wirings of the flexible printed circuit board shown in Figure 9 and the various electrodes of the piezoelectric substrate 30. As shown in Figure 13, in this embodiment, the first width W1 of the first part 441 of the analog signal wiring 44 in the mounting area 271 is larger than the width of the other analog signal wirings 44, and is also larger than the widths of the first resistance wiring 46 and the second resistance wiring 47, respectively. Therefore, the connection between the analog signal wiring 44 and the first resistance wiring 46 and the second resistance wiring 47 is made more reliable, and connection failures can be suppressed. As a result, the contact resistance between the analog signal wiring 44 and the first resistance wiring 46 and the second resistance wiring 47 can be reduced.

[0127] As described above, by increasing the resistance of the first resistance wiring 46 and the second resistance wiring 47 while lowering the contact resistance between the analog signal wiring 44 and the first resistance wiring 46 and the second resistance wiring 47, changes in the resistance values ​​of the first resistance wiring 46 and the second resistance wiring 47 can be detected with higher precision. Therefore, the amount of temperature change in the first nozzle row La and the second nozzle row Lb can be detected with higher precision.

[0128] Furthermore, this embodiment can also suppress variations in contact resistance among multiple liquid discharge modules 20. When the contact resistance values ​​differ among multiple liquid discharge modules, calibration is required to correct errors in the detected values ​​caused by variations in contact resistance. In this embodiment, the influence of contact resistance can be reduced, thus eliminating the need for calibration.

[0129] 2. Variations The embodiments illustrated above can be modified in various ways. Specific examples of modifications that can be applied to the aforementioned embodiments are given below. Two or more embodiments arbitrarily selected from the following examples can be combined as appropriate, to the extent that they do not contradict each other.

[0130] 2-1. First variation

[0131] The first resistor wire 46 is connected to the analog signal wire 44 and the second analog signal wire 45. On the other hand, the second resistor wire 47 is not connected to the analog signal wire 44 and the second analog signal wire 45. In this case, the second resistor wire 47 is connected to an analog signal wire different from the analog signal wire 44 and the second analog signal wire 45.

[0132] In this modified example, one resistor wire is connected to one analog signal wire. Therefore, it is possible to detect the temperature change of either the first nozzle row La or the second nozzle row Lb. The second resistor wiring 47 is not connected to the analog signal wiring 44 and the second analog signal wiring 45, but may be connected to, for example, the constant voltage wiring 42 or the second constant voltage wiring 43.

[0133] 2-2. Other variations In this embodiment, the first resistance wiring 46 and the second resistance wiring 47 are provided to detect changes in ink temperature within the pressure chamber C1, but are not limited to this. For example, the first resistance wiring 46 and the second resistance wiring 47 may be wiring for detecting the temperature and humidity of the liquid ejection module 20 other than the pressure chamber C1, the temperature and humidity near the liquid ejection module 20, or the ink pressure near the pressure chamber C1. The "liquid dispensing head" may be a circulating type head having a so-called circulation channel.

[0134] Liquid dispensing devices can be used in various types of equipment, including not only printing equipment but also facsimile machines and photocopiers. The applications of liquid dispensing devices are not limited to printing. For example, liquid dispensing devices that dispense colorant solutions are used as manufacturing equipment to form color filters for display devices such as liquid crystal display panels. Liquid dispensing devices that dispense conductive material solutions are used as manufacturing equipment to form wiring and electrodes on wiring boards. Furthermore, liquid dispensing devices that dispense solutions of organic substances related to living organisms are used, for example, as manufacturing equipment to produce biochips.

[0135] Although the present invention has been described above based on preferred embodiments, the present invention is not limited to the embodiments described above. Furthermore, the configuration of each part of the present invention can be replaced with any configuration that performs a similar function to the embodiments described above, and any configuration can be added.

[0136] 3. Addendum From the above embodiments or modifications, for example, the following embodiments can be understood.

[0137] A liquid discharge head according to a first embodiment, which is a preferred example of the present disclosure, comprises a piezoelectric substrate having a plurality of piezoelectric elements, a wiring board, and a flexible printed circuit board electrically connecting the piezoelectric substrate and the wiring board, wherein the flexible printed circuit board has a plurality of drive signal wirings for transmitting drive signals to drive the plurality of piezoelectric elements, analog signal wiring for transmitting analog signals, and constant voltage wiring held at a constant voltage, wherein the constant voltage wiring is arranged between the drive signal wiring and the analog signal wiring in a first direction intersecting the direction in which the constant voltage wiring is arranged.

[0138] This liquid dispensing head suppresses noise generated from the drive signal wiring from being superimposed on the analog signal wiring. Therefore, it provides a wiring design method with high signal transmission accuracy in analog signal wiring. This has been newly discovered.

[0139] In a liquid discharge head of the second embodiment, which is a preferred example of the first embodiment, the flexible printed circuit board is held at a constant voltage and has a second constant voltage wiring different from the constant voltage wiring, and in the first direction, the plurality of drive signal wirings are sandwiched between the constant voltage wiring and the second constant voltage wiring.

[0140] With such a liquid dispensing head, it is possible to suppress noise generated from the drive signal wiring from being superimposed on the analog signal wiring.

[0141] In the liquid discharge head of the third embodiment, which is a preferred example of the second embodiment, the flexible printed circuit board has no wiring between the edge of the flexible printed circuit board and the analog signal wiring in the first direction.

[0142] Such a liquid dispensing head can suppress noise generated from other wiring from being superimposed on the analog signal wiring.

[0143] In a liquid discharge head of a fourth embodiment, which is a preferred example of any of the first to third embodiments, the piezoelectric substrate has a plurality of piezoelectric parts, a common electrode provided in common to the plurality of piezoelectric parts, and a plurality of individual electrodes provided corresponding to the plurality of piezoelectric parts, the plurality of drive signal wirings are electrically connected one-to-one to the plurality of individual electrodes, the constant voltage wiring is electrically connected to the common electrode, and the direction of the current flowing through each of the plurality of drive signal wirings is opposite to the direction of the current flowing through the constant voltage wiring.

[0144] With such a liquid dispensing head, it is possible to suppress noise generated from the drive signal wiring from being superimposed on the analog signal wiring.

[0145] In a liquid discharge head of the fifth embodiment, which is a preferred example of any of the first to fourth embodiments, the flexible printed circuit board has a mounting area in which the plurality of drive signal wirings, the analog signal wirings, and the constant voltage wirings are connected to the piezoelectric substrate, and in the mounting area, the width of the analog signal wirings is greater than the width of the constant voltage wirings.

[0146] Such a liquid dispensing head can suppress stress on constant voltage wiring and multiple drive signal wiring that are located inside the analog signal wiring.

[0147] In the liquid discharge head of the sixth embodiment, which is a preferred example of the fifth embodiment, the width of the constant voltage wiring is greater than the width of the analog signal wiring in the non-mounted area of ​​the flexible printed circuit board, which is different from the mounted area.

[0148] With such a liquid dispensing head, it is possible to further suppress noise generated from the drive signal wiring from being superimposed on the analog signal wiring.

[0149] In a liquid discharge head of the seventh embodiment, which is a preferred example of any of the first to sixth embodiments, the piezoelectric substrate has 300 or more piezoelectric elements, and the plurality of drive signal wirings are electrically connected to the 300 or more piezoelectric elements.

[0150] The more piezoelectric elements there are, the easier it becomes for noise to be introduced into the analog signal wiring. In this case, it is particularly beneficial to have low-voltage wiring between the drive signal wiring and the analog signal wiring.

[0151] In the eighth embodiment, which is a preferred example of any of the first to seventh embodiments, the flexible printed circuit board has a mounting area in which the plurality of drive signal wirings, the analog signal wirings, and the constant voltage wirings are connected to the piezoelectric substrate, and the analog signal wiring has a first portion having a first width in the mounting area and a second portion having a second width that is narrower than the first portion and is located at the edge of the mounting area than the first portion.

[0152] With such a liquid dispensing head, the wide first section allows for more reliable connection between analog signal wiring and the wiring board in the mounting area.

[0153] In the liquid discharge head of the ninth embodiment, which is a preferred example of the eighth embodiment, the constant voltage wiring is exposed to the outside on the side surface of the flexible printed circuit board, the second portion of the analog signal wiring is exposed to the outside on the side surface, and in the first direction, the distance between the second portion and the constant voltage wiring is greater than the distance between the first portion and the constant voltage wiring.

[0154] With such a liquid dispensing head, by increasing the distance between the second part of the analog signal wiring and the constant voltage wiring, it is possible to suppress the electrical connection between the second part and the constant voltage wiring.

[0155] In a liquid discharge head of the tenth embodiment, which is a preferred example of the ninth embodiment, the analog signal wiring is a third part connected to the first part, the third part being narrower than the first part and wider than the constant voltage wiring.

[0156] With this liquid dispensing head, by making the first part located in the mounting area thicker than the third part, the strength of the wiring in the mounting area can be increased, and disconnection in the event of peeling or lifting can be suppressed.

[0157] In the liquid discharge head of the 11th embodiment, which is a preferred example of the 10th embodiment, the distance between the 3rd part and the constant voltage wiring in the first direction is smaller than the distance between the 2nd part and the constant voltage wiring.

[0158] With such a liquid dispensing head, the wiring board can be miniaturized by shortening the distance between the third part and the constant voltage wiring. In addition, by increasing the distance between the second part and the constant voltage wiring, it is possible to prevent the second part and the constant voltage wiring from becoming electrically connected.

[0159] In the liquid discharge head of the twelfth embodiment, which is a preferred example of any of the seventh to eleventh embodiments, the first part extends outside the mounting area.

[0160] With such a liquid dispensing head, the presence of the first part can suppress the unbending when it is bent.

[0161] In the liquid dispensing head of the 13th embodiment, which is a preferred example of any of the 7th to 11 embodiments, the first part is not provided with the material constituting the analog signal wiring, and has an opening provided in the analog signal wiring.

[0162] With this liquid discharge head, by providing the alignment mark opening in the analog signal wiring, it is possible to reduce the overall size of the flexible printed circuit board compared to a configuration where the alignment mark is provided separately in a location other than the analog signal wiring.

[0163] In the liquid discharge head of the 14th embodiment, which is a preferred example of any of the 1 to 13 embodiments, the analog signal wiring is arranged around a through-hole that penetrates the flexible printed circuit board.

[0164] With this type of liquid dispensing head, the rigidity around the through-hole can be increased by arranging analog signal wiring around the through-hole. Furthermore, corrosion can be prevented.

[0165] A liquid discharge head of the 15th embodiment, which is a preferred example of any of the 1 to 14 embodiments, comprises a nozzle substrate including a first nozzle row and a second nozzle row arranged in parallel in the direction along the first nozzle row, a first resistance wiring provided along the first nozzle row, and a second resistance wiring provided along the second nozzle row, wherein the first resistance wiring and the second resistance wiring are connected to the analog signal wiring.

[0166] In this type of liquid dispensing head, the first and second resistor wires are connected in parallel. Therefore, compared to a series connection, lower resistance can be achieved, allowing for the acquisition of analog signals with low power consumption.

[0167] A liquid discharge head according to the 16th embodiment, which is a preferred example of any of the 1 to 14 embodiments, comprises a nozzle substrate including a first nozzle row and a second nozzle row arranged in parallel in the direction along the first nozzle row, a first resistor wiring provided along the first nozzle row, and a second resistor wiring provided along the second nozzle row, wherein the first resistor wiring is connected to the analog signal wiring, and the second resistor wiring is not connected to the analog signal wiring.

[0168] With such a liquid dispensing head, it is possible to detect the change in temperature for at least the first nozzle row.

[0169] A liquid discharge head according to the 17th embodiment, which is a preferred example of any of the 1 to 16 embodiments, comprises a pressure chamber substrate connected to the piezoelectric substrate, the pressure chamber substrate having a pressure chamber whose volume changes due to deformation of the piezoelectric substrate, the piezoelectric substrate having a temperature sensing unit for detecting the temperature of the pressure chamber, and the analog signal wiring being electrically connected to the temperature sensing unit.

[0170] With this liquid dispensing head, minute changes in temperature can be detected based on the signal output from the temperature detection unit. [Explanation of Symbols]

[0171] 3…Head chip, 4…Flexible printed circuit board, 10…Control unit, 20…Liquid discharge module, 27…Wiring board, 30…Piezoelectric substrate, 31…Flow channel forming substrate, 32…Pressure chamber substrate, 33…Diaphragm, 37…Nozzle substrate, 41…Drive signal wiring, 42…Constant voltage wiring, 43…Second constant voltage wiring, 44…Analog signal wiring, 45…Second analog signal wiring, 46…First resistance wiring, 47…Second resistance wiring, 51…Individual electrodes, 52…Common electrodes, 53…Piezoelectric layer, 90…Medium, 100…Liquid discharge device, 200…Liquid discharge head, 270…Substrate, 270H…Through hole, 271…Mounting area 272...Unmounted area, 273...Curved part, 279...Edge, 441...First part, 442...Second part, 443...Third part, 44H...Opening, 531...Piezoelectric part, 2701...Identification mark, 2710...End, C1...Pressure chamber, COM...Drive signal, E...Piezoelectric element, L1...Distance, L2...Distance, L3...Distance, La...First nozzle row, Lb...Second nozzle row, N...Nozzle, S1...First area, S2...Second area, S3...Third area, TD...Physical information request signal, TH...Analog signal, TI...Physical information signal, VBS...Reference voltage signal, Vout...Drive signal, W1...First width, W2...Second width, W3...Third width.

Claims

1. A piezoelectric substrate having multiple piezoelectric elements, Wiring board and The system comprises a flexible printed circuit board that electrically connects the piezoelectric substrate and the wiring board, The aforementioned flexible printed circuit board is Multiple drive signal wirings for transmitting drive signals to drive the multiple piezoelectric elements, Analog signal wiring that transmits analog signals, It has a constant voltage wiring that is maintained at a constant voltage, The constant voltage wiring is arranged between the drive signal wiring and the analog signal wiring in a first direction intersecting the direction in which the constant voltage wiring is arranged. A liquid dispensing head characterized by the following features.

2. In the liquid discharge head according to claim 1, The flexible printed circuit board is held at a constant voltage and has a second constant voltage wiring different from the constant voltage wiring, In the first direction, The aforementioned multiple drive signal wirings are sandwiched between the constant voltage wiring and the second constant voltage wiring. A liquid dispensing head characterized by the following features.

3. In the liquid dispensing head according to claim 2, The flexible printed circuit board has no wiring between its edge and the analog signal wiring in the first direction. A liquid dispensing head characterized by the following features.

4. In the liquid dispensing head according to any one of claims 1 to 3, The piezoelectric substrate has a plurality of piezoelectric parts, a common electrode provided in common to the plurality of piezoelectric parts, and a plurality of individual electrodes provided corresponding to the plurality of piezoelectric parts. The aforementioned plurality of drive signal wirings are electrically connected one-to-one to the plurality of individual electrodes, The constant voltage wiring is electrically connected to the common electrode, The direction of the current flowing through each of the aforementioned multiple drive signal wires is opposite to the direction of the current flowing through the constant voltage wire. A liquid dispensing head characterized by the following features.

5. In the liquid dispensing head according to any one of claims 1 to 3, In the flexible printed circuit board, the area where the plurality of drive signal wirings, the analog signal wirings, and the constant voltage wirings are connected to the piezoelectric substrate is defined as the mounting area. In the aforementioned implementation area, The width of the analog signal wiring is greater than the width of the constant voltage wiring. A liquid dispensing head characterized by the following features.

6. In the liquid discharge head according to claim 5, In the non-mounted area of ​​the flexible printed circuit board, which is different from the mounted area, the width of the constant voltage wiring is greater than the width of the analog signal wiring. A liquid dispensing head characterized by the following features.

7. In the liquid dispensing head according to any one of claims 1 to 3, The piezoelectric substrate has 300 or more piezoelectric elements, The aforementioned multiple drive signal wirings are electrically connected to the 300 or more piezoelectric elements. A liquid dispensing head characterized by the following features.

8. In the liquid dispensing head according to any one of claims 1 to 3, In the flexible printed circuit board, the area where the plurality of drive signal wirings, the analog signal wirings, and the constant voltage wirings are connected to the piezoelectric substrate is defined as the mounting area. The analog signal wiring in the mounting area is The first part, which is the first panel, It has a second part which is located at the edge of the mounting area, and which has a second width that is narrower than the first width, A liquid dispensing head characterized by the following features.

9. In the liquid dispensing head according to claim 8, The constant voltage wiring is exposed to the outside at one end of the flexible printed circuit board. The second part of the analog signal wiring is exposed to the outside at one end. In the first direction, the distance between the second part and the constant voltage wiring is greater than the distance between the first part and the constant voltage wiring. A liquid dispensing head characterized by the following features.

10. In the liquid dispensing head according to claim 9, The analog signal wiring has a third part that connects to the first part, and the third part is narrower than the first part and wider than the constant voltage wiring. A liquid dispensing head characterized by the following features.

11. In the liquid dispensing head according to claim 10, In the first direction, the distance between the third part and the constant voltage wiring is smaller than the distance between the second part and the constant voltage wiring. A liquid dispensing head characterized by the following features.

12. In the liquid dispensing head according to claim 8, The first part extends outside the mounting area, A liquid dispensing head characterized by the following features.

13. In the liquid dispensing head according to claim 8, The first part is not provided with the material constituting the analog signal wiring, and has an opening provided in the analog signal wiring. A liquid dispensing head characterized by the following features.

14. In the liquid dispensing head according to any one of claims 1 to 3, The aforementioned analog signal wiring is arranged around the through-holes that penetrate the flexible printed circuit board. A liquid dispensing head characterized by the following features.

15. In the liquid dispensing head according to any one of claims 1 to 3, A nozzle substrate including a first nozzle row and a second nozzle row arranged in parallel along the first nozzle row, A first resistor wiring provided along the first nozzle row, It has a second resistor wiring provided along the second nozzle row, The first resistor wiring and the second resistor wiring are connected to the analog signal wiring. A liquid dispensing head characterized by the following features.

16. In the liquid dispensing head according to any one of claims 1 to 3, A nozzle substrate including a first nozzle row and a second nozzle row arranged in parallel along the first nozzle row, A first resistor wiring provided along the first nozzle row, It has a second resistor wiring provided along the second nozzle row, The first resistor wiring is connected to the analog signal wiring, The second resistor wiring is not connected to the analog signal wiring. A liquid dispensing head characterized by the following features.

17. In the liquid dispensing head according to any one of claims 1 to 3, A pressure chamber substrate connected to the piezoelectric substrate, comprising the pressure chamber substrate having a pressure chamber whose volume changes due to deformation of the piezoelectric substrate, The piezoelectric substrate has a temperature sensing unit for detecting the temperature of the pressure chamber, The analog signal wiring is electrically connected to the temperature sensing unit. A liquid dispensing head characterized by the following features.

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